| File: | src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaOverload.cpp |
| Warning: | line 9808, column 44 Called C++ object pointer is null |
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| 1 | //===--- SemaOverload.cpp - C++ Overloading -------------------------------===// |
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | // |
| 9 | // This file provides Sema routines for C++ overloading. |
| 10 | // |
| 11 | //===----------------------------------------------------------------------===// |
| 12 | |
| 13 | #include "clang/AST/ASTContext.h" |
| 14 | #include "clang/AST/CXXInheritance.h" |
| 15 | #include "clang/AST/DeclObjC.h" |
| 16 | #include "clang/AST/DependenceFlags.h" |
| 17 | #include "clang/AST/Expr.h" |
| 18 | #include "clang/AST/ExprCXX.h" |
| 19 | #include "clang/AST/ExprObjC.h" |
| 20 | #include "clang/AST/TypeOrdering.h" |
| 21 | #include "clang/Basic/Diagnostic.h" |
| 22 | #include "clang/Basic/DiagnosticOptions.h" |
| 23 | #include "clang/Basic/PartialDiagnostic.h" |
| 24 | #include "clang/Basic/SourceManager.h" |
| 25 | #include "clang/Basic/TargetInfo.h" |
| 26 | #include "clang/Sema/Initialization.h" |
| 27 | #include "clang/Sema/Lookup.h" |
| 28 | #include "clang/Sema/Overload.h" |
| 29 | #include "clang/Sema/SemaInternal.h" |
| 30 | #include "clang/Sema/Template.h" |
| 31 | #include "clang/Sema/TemplateDeduction.h" |
| 32 | #include "llvm/ADT/DenseSet.h" |
| 33 | #include "llvm/ADT/Optional.h" |
| 34 | #include "llvm/ADT/STLExtras.h" |
| 35 | #include "llvm/ADT/SmallPtrSet.h" |
| 36 | #include "llvm/ADT/SmallString.h" |
| 37 | #include <algorithm> |
| 38 | #include <cstdlib> |
| 39 | |
| 40 | using namespace clang; |
| 41 | using namespace sema; |
| 42 | |
| 43 | using AllowedExplicit = Sema::AllowedExplicit; |
| 44 | |
| 45 | static bool functionHasPassObjectSizeParams(const FunctionDecl *FD) { |
| 46 | return llvm::any_of(FD->parameters(), [](const ParmVarDecl *P) { |
| 47 | return P->hasAttr<PassObjectSizeAttr>(); |
| 48 | }); |
| 49 | } |
| 50 | |
| 51 | /// A convenience routine for creating a decayed reference to a function. |
| 52 | static ExprResult |
| 53 | CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl, |
| 54 | const Expr *Base, bool HadMultipleCandidates, |
| 55 | SourceLocation Loc = SourceLocation(), |
| 56 | const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){ |
| 57 | if (S.DiagnoseUseOfDecl(FoundDecl, Loc)) |
| 58 | return ExprError(); |
| 59 | // If FoundDecl is different from Fn (such as if one is a template |
| 60 | // and the other a specialization), make sure DiagnoseUseOfDecl is |
| 61 | // called on both. |
| 62 | // FIXME: This would be more comprehensively addressed by modifying |
| 63 | // DiagnoseUseOfDecl to accept both the FoundDecl and the decl |
| 64 | // being used. |
| 65 | if (FoundDecl != Fn && S.DiagnoseUseOfDecl(Fn, Loc)) |
| 66 | return ExprError(); |
| 67 | DeclRefExpr *DRE = new (S.Context) |
| 68 | DeclRefExpr(S.Context, Fn, false, Fn->getType(), VK_LValue, Loc, LocInfo); |
| 69 | if (HadMultipleCandidates) |
| 70 | DRE->setHadMultipleCandidates(true); |
| 71 | |
| 72 | S.MarkDeclRefReferenced(DRE, Base); |
| 73 | if (auto *FPT = DRE->getType()->getAs<FunctionProtoType>()) { |
| 74 | if (isUnresolvedExceptionSpec(FPT->getExceptionSpecType())) { |
| 75 | S.ResolveExceptionSpec(Loc, FPT); |
| 76 | DRE->setType(Fn->getType()); |
| 77 | } |
| 78 | } |
| 79 | return S.ImpCastExprToType(DRE, S.Context.getPointerType(DRE->getType()), |
| 80 | CK_FunctionToPointerDecay); |
| 81 | } |
| 82 | |
| 83 | static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, |
| 84 | bool InOverloadResolution, |
| 85 | StandardConversionSequence &SCS, |
| 86 | bool CStyle, |
| 87 | bool AllowObjCWritebackConversion); |
| 88 | |
| 89 | static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, |
| 90 | QualType &ToType, |
| 91 | bool InOverloadResolution, |
| 92 | StandardConversionSequence &SCS, |
| 93 | bool CStyle); |
| 94 | static OverloadingResult |
| 95 | IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, |
| 96 | UserDefinedConversionSequence& User, |
| 97 | OverloadCandidateSet& Conversions, |
| 98 | AllowedExplicit AllowExplicit, |
| 99 | bool AllowObjCConversionOnExplicit); |
| 100 | |
| 101 | static ImplicitConversionSequence::CompareKind |
| 102 | CompareStandardConversionSequences(Sema &S, SourceLocation Loc, |
| 103 | const StandardConversionSequence& SCS1, |
| 104 | const StandardConversionSequence& SCS2); |
| 105 | |
| 106 | static ImplicitConversionSequence::CompareKind |
| 107 | CompareQualificationConversions(Sema &S, |
| 108 | const StandardConversionSequence& SCS1, |
| 109 | const StandardConversionSequence& SCS2); |
| 110 | |
| 111 | static ImplicitConversionSequence::CompareKind |
| 112 | CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc, |
| 113 | const StandardConversionSequence& SCS1, |
| 114 | const StandardConversionSequence& SCS2); |
| 115 | |
| 116 | /// GetConversionRank - Retrieve the implicit conversion rank |
| 117 | /// corresponding to the given implicit conversion kind. |
| 118 | ImplicitConversionRank clang::GetConversionRank(ImplicitConversionKind Kind) { |
| 119 | static const ImplicitConversionRank |
| 120 | Rank[(int)ICK_Num_Conversion_Kinds] = { |
| 121 | ICR_Exact_Match, |
| 122 | ICR_Exact_Match, |
| 123 | ICR_Exact_Match, |
| 124 | ICR_Exact_Match, |
| 125 | ICR_Exact_Match, |
| 126 | ICR_Exact_Match, |
| 127 | ICR_Promotion, |
| 128 | ICR_Promotion, |
| 129 | ICR_Promotion, |
| 130 | ICR_Conversion, |
| 131 | ICR_Conversion, |
| 132 | ICR_Conversion, |
| 133 | ICR_Conversion, |
| 134 | ICR_Conversion, |
| 135 | ICR_Conversion, |
| 136 | ICR_Conversion, |
| 137 | ICR_Conversion, |
| 138 | ICR_Conversion, |
| 139 | ICR_Conversion, |
| 140 | ICR_Conversion, |
| 141 | ICR_OCL_Scalar_Widening, |
| 142 | ICR_Complex_Real_Conversion, |
| 143 | ICR_Conversion, |
| 144 | ICR_Conversion, |
| 145 | ICR_Writeback_Conversion, |
| 146 | ICR_Exact_Match, // NOTE(gbiv): This may not be completely right -- |
| 147 | // it was omitted by the patch that added |
| 148 | // ICK_Zero_Event_Conversion |
| 149 | ICR_C_Conversion, |
| 150 | ICR_C_Conversion_Extension |
| 151 | }; |
| 152 | return Rank[(int)Kind]; |
| 153 | } |
| 154 | |
| 155 | /// GetImplicitConversionName - Return the name of this kind of |
| 156 | /// implicit conversion. |
| 157 | static const char* GetImplicitConversionName(ImplicitConversionKind Kind) { |
| 158 | static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { |
| 159 | "No conversion", |
| 160 | "Lvalue-to-rvalue", |
| 161 | "Array-to-pointer", |
| 162 | "Function-to-pointer", |
| 163 | "Function pointer conversion", |
| 164 | "Qualification", |
| 165 | "Integral promotion", |
| 166 | "Floating point promotion", |
| 167 | "Complex promotion", |
| 168 | "Integral conversion", |
| 169 | "Floating conversion", |
| 170 | "Complex conversion", |
| 171 | "Floating-integral conversion", |
| 172 | "Pointer conversion", |
| 173 | "Pointer-to-member conversion", |
| 174 | "Boolean conversion", |
| 175 | "Compatible-types conversion", |
| 176 | "Derived-to-base conversion", |
| 177 | "Vector conversion", |
| 178 | "SVE Vector conversion", |
| 179 | "Vector splat", |
| 180 | "Complex-real conversion", |
| 181 | "Block Pointer conversion", |
| 182 | "Transparent Union Conversion", |
| 183 | "Writeback conversion", |
| 184 | "OpenCL Zero Event Conversion", |
| 185 | "C specific type conversion", |
| 186 | "Incompatible pointer conversion" |
| 187 | }; |
| 188 | return Name[Kind]; |
| 189 | } |
| 190 | |
| 191 | /// StandardConversionSequence - Set the standard conversion |
| 192 | /// sequence to the identity conversion. |
| 193 | void StandardConversionSequence::setAsIdentityConversion() { |
| 194 | First = ICK_Identity; |
| 195 | Second = ICK_Identity; |
| 196 | Third = ICK_Identity; |
| 197 | DeprecatedStringLiteralToCharPtr = false; |
| 198 | QualificationIncludesObjCLifetime = false; |
| 199 | ReferenceBinding = false; |
| 200 | DirectBinding = false; |
| 201 | IsLvalueReference = true; |
| 202 | BindsToFunctionLvalue = false; |
| 203 | BindsToRvalue = false; |
| 204 | BindsImplicitObjectArgumentWithoutRefQualifier = false; |
| 205 | ObjCLifetimeConversionBinding = false; |
| 206 | CopyConstructor = nullptr; |
| 207 | } |
| 208 | |
| 209 | /// getRank - Retrieve the rank of this standard conversion sequence |
| 210 | /// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the |
| 211 | /// implicit conversions. |
| 212 | ImplicitConversionRank StandardConversionSequence::getRank() const { |
| 213 | ImplicitConversionRank Rank = ICR_Exact_Match; |
| 214 | if (GetConversionRank(First) > Rank) |
| 215 | Rank = GetConversionRank(First); |
| 216 | if (GetConversionRank(Second) > Rank) |
| 217 | Rank = GetConversionRank(Second); |
| 218 | if (GetConversionRank(Third) > Rank) |
| 219 | Rank = GetConversionRank(Third); |
| 220 | return Rank; |
| 221 | } |
| 222 | |
| 223 | /// isPointerConversionToBool - Determines whether this conversion is |
| 224 | /// a conversion of a pointer or pointer-to-member to bool. This is |
| 225 | /// used as part of the ranking of standard conversion sequences |
| 226 | /// (C++ 13.3.3.2p4). |
| 227 | bool StandardConversionSequence::isPointerConversionToBool() const { |
| 228 | // Note that FromType has not necessarily been transformed by the |
| 229 | // array-to-pointer or function-to-pointer implicit conversions, so |
| 230 | // check for their presence as well as checking whether FromType is |
| 231 | // a pointer. |
| 232 | if (getToType(1)->isBooleanType() && |
| 233 | (getFromType()->isPointerType() || |
| 234 | getFromType()->isMemberPointerType() || |
| 235 | getFromType()->isObjCObjectPointerType() || |
| 236 | getFromType()->isBlockPointerType() || |
| 237 | First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) |
| 238 | return true; |
| 239 | |
| 240 | return false; |
| 241 | } |
| 242 | |
| 243 | /// isPointerConversionToVoidPointer - Determines whether this |
| 244 | /// conversion is a conversion of a pointer to a void pointer. This is |
| 245 | /// used as part of the ranking of standard conversion sequences (C++ |
| 246 | /// 13.3.3.2p4). |
| 247 | bool |
| 248 | StandardConversionSequence:: |
| 249 | isPointerConversionToVoidPointer(ASTContext& Context) const { |
| 250 | QualType FromType = getFromType(); |
| 251 | QualType ToType = getToType(1); |
| 252 | |
| 253 | // Note that FromType has not necessarily been transformed by the |
| 254 | // array-to-pointer implicit conversion, so check for its presence |
| 255 | // and redo the conversion to get a pointer. |
| 256 | if (First == ICK_Array_To_Pointer) |
| 257 | FromType = Context.getArrayDecayedType(FromType); |
| 258 | |
| 259 | if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType()) |
| 260 | if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) |
| 261 | return ToPtrType->getPointeeType()->isVoidType(); |
| 262 | |
| 263 | return false; |
| 264 | } |
| 265 | |
| 266 | /// Skip any implicit casts which could be either part of a narrowing conversion |
| 267 | /// or after one in an implicit conversion. |
| 268 | static const Expr *IgnoreNarrowingConversion(ASTContext &Ctx, |
| 269 | const Expr *Converted) { |
| 270 | // We can have cleanups wrapping the converted expression; these need to be |
| 271 | // preserved so that destructors run if necessary. |
| 272 | if (auto *EWC = dyn_cast<ExprWithCleanups>(Converted)) { |
| 273 | Expr *Inner = |
| 274 | const_cast<Expr *>(IgnoreNarrowingConversion(Ctx, EWC->getSubExpr())); |
| 275 | return ExprWithCleanups::Create(Ctx, Inner, EWC->cleanupsHaveSideEffects(), |
| 276 | EWC->getObjects()); |
| 277 | } |
| 278 | |
| 279 | while (auto *ICE = dyn_cast<ImplicitCastExpr>(Converted)) { |
| 280 | switch (ICE->getCastKind()) { |
| 281 | case CK_NoOp: |
| 282 | case CK_IntegralCast: |
| 283 | case CK_IntegralToBoolean: |
| 284 | case CK_IntegralToFloating: |
| 285 | case CK_BooleanToSignedIntegral: |
| 286 | case CK_FloatingToIntegral: |
| 287 | case CK_FloatingToBoolean: |
| 288 | case CK_FloatingCast: |
| 289 | Converted = ICE->getSubExpr(); |
| 290 | continue; |
| 291 | |
| 292 | default: |
| 293 | return Converted; |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | return Converted; |
| 298 | } |
| 299 | |
| 300 | /// Check if this standard conversion sequence represents a narrowing |
| 301 | /// conversion, according to C++11 [dcl.init.list]p7. |
| 302 | /// |
| 303 | /// \param Ctx The AST context. |
| 304 | /// \param Converted The result of applying this standard conversion sequence. |
| 305 | /// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the |
| 306 | /// value of the expression prior to the narrowing conversion. |
| 307 | /// \param ConstantType If this is an NK_Constant_Narrowing conversion, the |
| 308 | /// type of the expression prior to the narrowing conversion. |
| 309 | /// \param IgnoreFloatToIntegralConversion If true type-narrowing conversions |
| 310 | /// from floating point types to integral types should be ignored. |
| 311 | NarrowingKind StandardConversionSequence::getNarrowingKind( |
| 312 | ASTContext &Ctx, const Expr *Converted, APValue &ConstantValue, |
| 313 | QualType &ConstantType, bool IgnoreFloatToIntegralConversion) const { |
| 314 | assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++")((void)0); |
| 315 | |
| 316 | // C++11 [dcl.init.list]p7: |
| 317 | // A narrowing conversion is an implicit conversion ... |
| 318 | QualType FromType = getToType(0); |
| 319 | QualType ToType = getToType(1); |
| 320 | |
| 321 | // A conversion to an enumeration type is narrowing if the conversion to |
| 322 | // the underlying type is narrowing. This only arises for expressions of |
| 323 | // the form 'Enum{init}'. |
| 324 | if (auto *ET = ToType->getAs<EnumType>()) |
| 325 | ToType = ET->getDecl()->getIntegerType(); |
| 326 | |
| 327 | switch (Second) { |
| 328 | // 'bool' is an integral type; dispatch to the right place to handle it. |
| 329 | case ICK_Boolean_Conversion: |
| 330 | if (FromType->isRealFloatingType()) |
| 331 | goto FloatingIntegralConversion; |
| 332 | if (FromType->isIntegralOrUnscopedEnumerationType()) |
| 333 | goto IntegralConversion; |
| 334 | // -- from a pointer type or pointer-to-member type to bool, or |
| 335 | return NK_Type_Narrowing; |
| 336 | |
| 337 | // -- from a floating-point type to an integer type, or |
| 338 | // |
| 339 | // -- from an integer type or unscoped enumeration type to a floating-point |
| 340 | // type, except where the source is a constant expression and the actual |
| 341 | // value after conversion will fit into the target type and will produce |
| 342 | // the original value when converted back to the original type, or |
| 343 | case ICK_Floating_Integral: |
| 344 | FloatingIntegralConversion: |
| 345 | if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) { |
| 346 | return NK_Type_Narrowing; |
| 347 | } else if (FromType->isIntegralOrUnscopedEnumerationType() && |
| 348 | ToType->isRealFloatingType()) { |
| 349 | if (IgnoreFloatToIntegralConversion) |
| 350 | return NK_Not_Narrowing; |
| 351 | const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted); |
| 352 | assert(Initializer && "Unknown conversion expression")((void)0); |
| 353 | |
| 354 | // If it's value-dependent, we can't tell whether it's narrowing. |
| 355 | if (Initializer->isValueDependent()) |
| 356 | return NK_Dependent_Narrowing; |
| 357 | |
| 358 | if (Optional<llvm::APSInt> IntConstantValue = |
| 359 | Initializer->getIntegerConstantExpr(Ctx)) { |
| 360 | // Convert the integer to the floating type. |
| 361 | llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType)); |
| 362 | Result.convertFromAPInt(*IntConstantValue, IntConstantValue->isSigned(), |
| 363 | llvm::APFloat::rmNearestTiesToEven); |
| 364 | // And back. |
| 365 | llvm::APSInt ConvertedValue = *IntConstantValue; |
| 366 | bool ignored; |
| 367 | Result.convertToInteger(ConvertedValue, |
| 368 | llvm::APFloat::rmTowardZero, &ignored); |
| 369 | // If the resulting value is different, this was a narrowing conversion. |
| 370 | if (*IntConstantValue != ConvertedValue) { |
| 371 | ConstantValue = APValue(*IntConstantValue); |
| 372 | ConstantType = Initializer->getType(); |
| 373 | return NK_Constant_Narrowing; |
| 374 | } |
| 375 | } else { |
| 376 | // Variables are always narrowings. |
| 377 | return NK_Variable_Narrowing; |
| 378 | } |
| 379 | } |
| 380 | return NK_Not_Narrowing; |
| 381 | |
| 382 | // -- from long double to double or float, or from double to float, except |
| 383 | // where the source is a constant expression and the actual value after |
| 384 | // conversion is within the range of values that can be represented (even |
| 385 | // if it cannot be represented exactly), or |
| 386 | case ICK_Floating_Conversion: |
| 387 | if (FromType->isRealFloatingType() && ToType->isRealFloatingType() && |
| 388 | Ctx.getFloatingTypeOrder(FromType, ToType) == 1) { |
| 389 | // FromType is larger than ToType. |
| 390 | const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted); |
| 391 | |
| 392 | // If it's value-dependent, we can't tell whether it's narrowing. |
| 393 | if (Initializer->isValueDependent()) |
| 394 | return NK_Dependent_Narrowing; |
| 395 | |
| 396 | if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) { |
| 397 | // Constant! |
| 398 | assert(ConstantValue.isFloat())((void)0); |
| 399 | llvm::APFloat FloatVal = ConstantValue.getFloat(); |
| 400 | // Convert the source value into the target type. |
| 401 | bool ignored; |
| 402 | llvm::APFloat::opStatus ConvertStatus = FloatVal.convert( |
| 403 | Ctx.getFloatTypeSemantics(ToType), |
| 404 | llvm::APFloat::rmNearestTiesToEven, &ignored); |
| 405 | // If there was no overflow, the source value is within the range of |
| 406 | // values that can be represented. |
| 407 | if (ConvertStatus & llvm::APFloat::opOverflow) { |
| 408 | ConstantType = Initializer->getType(); |
| 409 | return NK_Constant_Narrowing; |
| 410 | } |
| 411 | } else { |
| 412 | return NK_Variable_Narrowing; |
| 413 | } |
| 414 | } |
| 415 | return NK_Not_Narrowing; |
| 416 | |
| 417 | // -- from an integer type or unscoped enumeration type to an integer type |
| 418 | // that cannot represent all the values of the original type, except where |
| 419 | // the source is a constant expression and the actual value after |
| 420 | // conversion will fit into the target type and will produce the original |
| 421 | // value when converted back to the original type. |
| 422 | case ICK_Integral_Conversion: |
| 423 | IntegralConversion: { |
| 424 | assert(FromType->isIntegralOrUnscopedEnumerationType())((void)0); |
| 425 | assert(ToType->isIntegralOrUnscopedEnumerationType())((void)0); |
| 426 | const bool FromSigned = FromType->isSignedIntegerOrEnumerationType(); |
| 427 | const unsigned FromWidth = Ctx.getIntWidth(FromType); |
| 428 | const bool ToSigned = ToType->isSignedIntegerOrEnumerationType(); |
| 429 | const unsigned ToWidth = Ctx.getIntWidth(ToType); |
| 430 | |
| 431 | if (FromWidth > ToWidth || |
| 432 | (FromWidth == ToWidth && FromSigned != ToSigned) || |
| 433 | (FromSigned && !ToSigned)) { |
| 434 | // Not all values of FromType can be represented in ToType. |
| 435 | const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted); |
| 436 | |
| 437 | // If it's value-dependent, we can't tell whether it's narrowing. |
| 438 | if (Initializer->isValueDependent()) |
| 439 | return NK_Dependent_Narrowing; |
| 440 | |
| 441 | Optional<llvm::APSInt> OptInitializerValue; |
| 442 | if (!(OptInitializerValue = Initializer->getIntegerConstantExpr(Ctx))) { |
| 443 | // Such conversions on variables are always narrowing. |
| 444 | return NK_Variable_Narrowing; |
| 445 | } |
| 446 | llvm::APSInt &InitializerValue = *OptInitializerValue; |
| 447 | bool Narrowing = false; |
| 448 | if (FromWidth < ToWidth) { |
| 449 | // Negative -> unsigned is narrowing. Otherwise, more bits is never |
| 450 | // narrowing. |
| 451 | if (InitializerValue.isSigned() && InitializerValue.isNegative()) |
| 452 | Narrowing = true; |
| 453 | } else { |
| 454 | // Add a bit to the InitializerValue so we don't have to worry about |
| 455 | // signed vs. unsigned comparisons. |
| 456 | InitializerValue = InitializerValue.extend( |
| 457 | InitializerValue.getBitWidth() + 1); |
| 458 | // Convert the initializer to and from the target width and signed-ness. |
| 459 | llvm::APSInt ConvertedValue = InitializerValue; |
| 460 | ConvertedValue = ConvertedValue.trunc(ToWidth); |
| 461 | ConvertedValue.setIsSigned(ToSigned); |
| 462 | ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth()); |
| 463 | ConvertedValue.setIsSigned(InitializerValue.isSigned()); |
| 464 | // If the result is different, this was a narrowing conversion. |
| 465 | if (ConvertedValue != InitializerValue) |
| 466 | Narrowing = true; |
| 467 | } |
| 468 | if (Narrowing) { |
| 469 | ConstantType = Initializer->getType(); |
| 470 | ConstantValue = APValue(InitializerValue); |
| 471 | return NK_Constant_Narrowing; |
| 472 | } |
| 473 | } |
| 474 | return NK_Not_Narrowing; |
| 475 | } |
| 476 | |
| 477 | default: |
| 478 | // Other kinds of conversions are not narrowings. |
| 479 | return NK_Not_Narrowing; |
| 480 | } |
| 481 | } |
| 482 | |
| 483 | /// dump - Print this standard conversion sequence to standard |
| 484 | /// error. Useful for debugging overloading issues. |
| 485 | LLVM_DUMP_METHOD__attribute__((noinline)) void StandardConversionSequence::dump() const { |
| 486 | raw_ostream &OS = llvm::errs(); |
| 487 | bool PrintedSomething = false; |
| 488 | if (First != ICK_Identity) { |
| 489 | OS << GetImplicitConversionName(First); |
| 490 | PrintedSomething = true; |
| 491 | } |
| 492 | |
| 493 | if (Second != ICK_Identity) { |
| 494 | if (PrintedSomething) { |
| 495 | OS << " -> "; |
| 496 | } |
| 497 | OS << GetImplicitConversionName(Second); |
| 498 | |
| 499 | if (CopyConstructor) { |
| 500 | OS << " (by copy constructor)"; |
| 501 | } else if (DirectBinding) { |
| 502 | OS << " (direct reference binding)"; |
| 503 | } else if (ReferenceBinding) { |
| 504 | OS << " (reference binding)"; |
| 505 | } |
| 506 | PrintedSomething = true; |
| 507 | } |
| 508 | |
| 509 | if (Third != ICK_Identity) { |
| 510 | if (PrintedSomething) { |
| 511 | OS << " -> "; |
| 512 | } |
| 513 | OS << GetImplicitConversionName(Third); |
| 514 | PrintedSomething = true; |
| 515 | } |
| 516 | |
| 517 | if (!PrintedSomething) { |
| 518 | OS << "No conversions required"; |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | /// dump - Print this user-defined conversion sequence to standard |
| 523 | /// error. Useful for debugging overloading issues. |
| 524 | void UserDefinedConversionSequence::dump() const { |
| 525 | raw_ostream &OS = llvm::errs(); |
| 526 | if (Before.First || Before.Second || Before.Third) { |
| 527 | Before.dump(); |
| 528 | OS << " -> "; |
| 529 | } |
| 530 | if (ConversionFunction) |
| 531 | OS << '\'' << *ConversionFunction << '\''; |
| 532 | else |
| 533 | OS << "aggregate initialization"; |
| 534 | if (After.First || After.Second || After.Third) { |
| 535 | OS << " -> "; |
| 536 | After.dump(); |
| 537 | } |
| 538 | } |
| 539 | |
| 540 | /// dump - Print this implicit conversion sequence to standard |
| 541 | /// error. Useful for debugging overloading issues. |
| 542 | void ImplicitConversionSequence::dump() const { |
| 543 | raw_ostream &OS = llvm::errs(); |
| 544 | if (isStdInitializerListElement()) |
| 545 | OS << "Worst std::initializer_list element conversion: "; |
| 546 | switch (ConversionKind) { |
| 547 | case StandardConversion: |
| 548 | OS << "Standard conversion: "; |
| 549 | Standard.dump(); |
| 550 | break; |
| 551 | case UserDefinedConversion: |
| 552 | OS << "User-defined conversion: "; |
| 553 | UserDefined.dump(); |
| 554 | break; |
| 555 | case EllipsisConversion: |
| 556 | OS << "Ellipsis conversion"; |
| 557 | break; |
| 558 | case AmbiguousConversion: |
| 559 | OS << "Ambiguous conversion"; |
| 560 | break; |
| 561 | case BadConversion: |
| 562 | OS << "Bad conversion"; |
| 563 | break; |
| 564 | } |
| 565 | |
| 566 | OS << "\n"; |
| 567 | } |
| 568 | |
| 569 | void AmbiguousConversionSequence::construct() { |
| 570 | new (&conversions()) ConversionSet(); |
| 571 | } |
| 572 | |
| 573 | void AmbiguousConversionSequence::destruct() { |
| 574 | conversions().~ConversionSet(); |
| 575 | } |
| 576 | |
| 577 | void |
| 578 | AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { |
| 579 | FromTypePtr = O.FromTypePtr; |
| 580 | ToTypePtr = O.ToTypePtr; |
| 581 | new (&conversions()) ConversionSet(O.conversions()); |
| 582 | } |
| 583 | |
| 584 | namespace { |
| 585 | // Structure used by DeductionFailureInfo to store |
| 586 | // template argument information. |
| 587 | struct DFIArguments { |
| 588 | TemplateArgument FirstArg; |
| 589 | TemplateArgument SecondArg; |
| 590 | }; |
| 591 | // Structure used by DeductionFailureInfo to store |
| 592 | // template parameter and template argument information. |
| 593 | struct DFIParamWithArguments : DFIArguments { |
| 594 | TemplateParameter Param; |
| 595 | }; |
| 596 | // Structure used by DeductionFailureInfo to store template argument |
| 597 | // information and the index of the problematic call argument. |
| 598 | struct DFIDeducedMismatchArgs : DFIArguments { |
| 599 | TemplateArgumentList *TemplateArgs; |
| 600 | unsigned CallArgIndex; |
| 601 | }; |
| 602 | // Structure used by DeductionFailureInfo to store information about |
| 603 | // unsatisfied constraints. |
| 604 | struct CNSInfo { |
| 605 | TemplateArgumentList *TemplateArgs; |
| 606 | ConstraintSatisfaction Satisfaction; |
| 607 | }; |
| 608 | } |
| 609 | |
| 610 | /// Convert from Sema's representation of template deduction information |
| 611 | /// to the form used in overload-candidate information. |
| 612 | DeductionFailureInfo |
| 613 | clang::MakeDeductionFailureInfo(ASTContext &Context, |
| 614 | Sema::TemplateDeductionResult TDK, |
| 615 | TemplateDeductionInfo &Info) { |
| 616 | DeductionFailureInfo Result; |
| 617 | Result.Result = static_cast<unsigned>(TDK); |
| 618 | Result.HasDiagnostic = false; |
| 619 | switch (TDK) { |
| 620 | case Sema::TDK_Invalid: |
| 621 | case Sema::TDK_InstantiationDepth: |
| 622 | case Sema::TDK_TooManyArguments: |
| 623 | case Sema::TDK_TooFewArguments: |
| 624 | case Sema::TDK_MiscellaneousDeductionFailure: |
| 625 | case Sema::TDK_CUDATargetMismatch: |
| 626 | Result.Data = nullptr; |
| 627 | break; |
| 628 | |
| 629 | case Sema::TDK_Incomplete: |
| 630 | case Sema::TDK_InvalidExplicitArguments: |
| 631 | Result.Data = Info.Param.getOpaqueValue(); |
| 632 | break; |
| 633 | |
| 634 | case Sema::TDK_DeducedMismatch: |
| 635 | case Sema::TDK_DeducedMismatchNested: { |
| 636 | // FIXME: Should allocate from normal heap so that we can free this later. |
| 637 | auto *Saved = new (Context) DFIDeducedMismatchArgs; |
| 638 | Saved->FirstArg = Info.FirstArg; |
| 639 | Saved->SecondArg = Info.SecondArg; |
| 640 | Saved->TemplateArgs = Info.take(); |
| 641 | Saved->CallArgIndex = Info.CallArgIndex; |
| 642 | Result.Data = Saved; |
| 643 | break; |
| 644 | } |
| 645 | |
| 646 | case Sema::TDK_NonDeducedMismatch: { |
| 647 | // FIXME: Should allocate from normal heap so that we can free this later. |
| 648 | DFIArguments *Saved = new (Context) DFIArguments; |
| 649 | Saved->FirstArg = Info.FirstArg; |
| 650 | Saved->SecondArg = Info.SecondArg; |
| 651 | Result.Data = Saved; |
| 652 | break; |
| 653 | } |
| 654 | |
| 655 | case Sema::TDK_IncompletePack: |
| 656 | // FIXME: It's slightly wasteful to allocate two TemplateArguments for this. |
| 657 | case Sema::TDK_Inconsistent: |
| 658 | case Sema::TDK_Underqualified: { |
| 659 | // FIXME: Should allocate from normal heap so that we can free this later. |
| 660 | DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; |
| 661 | Saved->Param = Info.Param; |
| 662 | Saved->FirstArg = Info.FirstArg; |
| 663 | Saved->SecondArg = Info.SecondArg; |
| 664 | Result.Data = Saved; |
| 665 | break; |
| 666 | } |
| 667 | |
| 668 | case Sema::TDK_SubstitutionFailure: |
| 669 | Result.Data = Info.take(); |
| 670 | if (Info.hasSFINAEDiagnostic()) { |
| 671 | PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt( |
| 672 | SourceLocation(), PartialDiagnostic::NullDiagnostic()); |
| 673 | Info.takeSFINAEDiagnostic(*Diag); |
| 674 | Result.HasDiagnostic = true; |
| 675 | } |
| 676 | break; |
| 677 | |
| 678 | case Sema::TDK_ConstraintsNotSatisfied: { |
| 679 | CNSInfo *Saved = new (Context) CNSInfo; |
| 680 | Saved->TemplateArgs = Info.take(); |
| 681 | Saved->Satisfaction = Info.AssociatedConstraintsSatisfaction; |
| 682 | Result.Data = Saved; |
| 683 | break; |
| 684 | } |
| 685 | |
| 686 | case Sema::TDK_Success: |
| 687 | case Sema::TDK_NonDependentConversionFailure: |
| 688 | llvm_unreachable("not a deduction failure")__builtin_unreachable(); |
| 689 | } |
| 690 | |
| 691 | return Result; |
| 692 | } |
| 693 | |
| 694 | void DeductionFailureInfo::Destroy() { |
| 695 | switch (static_cast<Sema::TemplateDeductionResult>(Result)) { |
| 696 | case Sema::TDK_Success: |
| 697 | case Sema::TDK_Invalid: |
| 698 | case Sema::TDK_InstantiationDepth: |
| 699 | case Sema::TDK_Incomplete: |
| 700 | case Sema::TDK_TooManyArguments: |
| 701 | case Sema::TDK_TooFewArguments: |
| 702 | case Sema::TDK_InvalidExplicitArguments: |
| 703 | case Sema::TDK_CUDATargetMismatch: |
| 704 | case Sema::TDK_NonDependentConversionFailure: |
| 705 | break; |
| 706 | |
| 707 | case Sema::TDK_IncompletePack: |
| 708 | case Sema::TDK_Inconsistent: |
| 709 | case Sema::TDK_Underqualified: |
| 710 | case Sema::TDK_DeducedMismatch: |
| 711 | case Sema::TDK_DeducedMismatchNested: |
| 712 | case Sema::TDK_NonDeducedMismatch: |
| 713 | // FIXME: Destroy the data? |
| 714 | Data = nullptr; |
| 715 | break; |
| 716 | |
| 717 | case Sema::TDK_SubstitutionFailure: |
| 718 | // FIXME: Destroy the template argument list? |
| 719 | Data = nullptr; |
| 720 | if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) { |
| 721 | Diag->~PartialDiagnosticAt(); |
| 722 | HasDiagnostic = false; |
| 723 | } |
| 724 | break; |
| 725 | |
| 726 | case Sema::TDK_ConstraintsNotSatisfied: |
| 727 | // FIXME: Destroy the template argument list? |
| 728 | Data = nullptr; |
| 729 | if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) { |
| 730 | Diag->~PartialDiagnosticAt(); |
| 731 | HasDiagnostic = false; |
| 732 | } |
| 733 | break; |
| 734 | |
| 735 | // Unhandled |
| 736 | case Sema::TDK_MiscellaneousDeductionFailure: |
| 737 | break; |
| 738 | } |
| 739 | } |
| 740 | |
| 741 | PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() { |
| 742 | if (HasDiagnostic) |
| 743 | return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic)); |
| 744 | return nullptr; |
| 745 | } |
| 746 | |
| 747 | TemplateParameter DeductionFailureInfo::getTemplateParameter() { |
| 748 | switch (static_cast<Sema::TemplateDeductionResult>(Result)) { |
| 749 | case Sema::TDK_Success: |
| 750 | case Sema::TDK_Invalid: |
| 751 | case Sema::TDK_InstantiationDepth: |
| 752 | case Sema::TDK_TooManyArguments: |
| 753 | case Sema::TDK_TooFewArguments: |
| 754 | case Sema::TDK_SubstitutionFailure: |
| 755 | case Sema::TDK_DeducedMismatch: |
| 756 | case Sema::TDK_DeducedMismatchNested: |
| 757 | case Sema::TDK_NonDeducedMismatch: |
| 758 | case Sema::TDK_CUDATargetMismatch: |
| 759 | case Sema::TDK_NonDependentConversionFailure: |
| 760 | case Sema::TDK_ConstraintsNotSatisfied: |
| 761 | return TemplateParameter(); |
| 762 | |
| 763 | case Sema::TDK_Incomplete: |
| 764 | case Sema::TDK_InvalidExplicitArguments: |
| 765 | return TemplateParameter::getFromOpaqueValue(Data); |
| 766 | |
| 767 | case Sema::TDK_IncompletePack: |
| 768 | case Sema::TDK_Inconsistent: |
| 769 | case Sema::TDK_Underqualified: |
| 770 | return static_cast<DFIParamWithArguments*>(Data)->Param; |
| 771 | |
| 772 | // Unhandled |
| 773 | case Sema::TDK_MiscellaneousDeductionFailure: |
| 774 | break; |
| 775 | } |
| 776 | |
| 777 | return TemplateParameter(); |
| 778 | } |
| 779 | |
| 780 | TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() { |
| 781 | switch (static_cast<Sema::TemplateDeductionResult>(Result)) { |
| 782 | case Sema::TDK_Success: |
| 783 | case Sema::TDK_Invalid: |
| 784 | case Sema::TDK_InstantiationDepth: |
| 785 | case Sema::TDK_TooManyArguments: |
| 786 | case Sema::TDK_TooFewArguments: |
| 787 | case Sema::TDK_Incomplete: |
| 788 | case Sema::TDK_IncompletePack: |
| 789 | case Sema::TDK_InvalidExplicitArguments: |
| 790 | case Sema::TDK_Inconsistent: |
| 791 | case Sema::TDK_Underqualified: |
| 792 | case Sema::TDK_NonDeducedMismatch: |
| 793 | case Sema::TDK_CUDATargetMismatch: |
| 794 | case Sema::TDK_NonDependentConversionFailure: |
| 795 | return nullptr; |
| 796 | |
| 797 | case Sema::TDK_DeducedMismatch: |
| 798 | case Sema::TDK_DeducedMismatchNested: |
| 799 | return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs; |
| 800 | |
| 801 | case Sema::TDK_SubstitutionFailure: |
| 802 | return static_cast<TemplateArgumentList*>(Data); |
| 803 | |
| 804 | case Sema::TDK_ConstraintsNotSatisfied: |
| 805 | return static_cast<CNSInfo*>(Data)->TemplateArgs; |
| 806 | |
| 807 | // Unhandled |
| 808 | case Sema::TDK_MiscellaneousDeductionFailure: |
| 809 | break; |
| 810 | } |
| 811 | |
| 812 | return nullptr; |
| 813 | } |
| 814 | |
| 815 | const TemplateArgument *DeductionFailureInfo::getFirstArg() { |
| 816 | switch (static_cast<Sema::TemplateDeductionResult>(Result)) { |
| 817 | case Sema::TDK_Success: |
| 818 | case Sema::TDK_Invalid: |
| 819 | case Sema::TDK_InstantiationDepth: |
| 820 | case Sema::TDK_Incomplete: |
| 821 | case Sema::TDK_TooManyArguments: |
| 822 | case Sema::TDK_TooFewArguments: |
| 823 | case Sema::TDK_InvalidExplicitArguments: |
| 824 | case Sema::TDK_SubstitutionFailure: |
| 825 | case Sema::TDK_CUDATargetMismatch: |
| 826 | case Sema::TDK_NonDependentConversionFailure: |
| 827 | case Sema::TDK_ConstraintsNotSatisfied: |
| 828 | return nullptr; |
| 829 | |
| 830 | case Sema::TDK_IncompletePack: |
| 831 | case Sema::TDK_Inconsistent: |
| 832 | case Sema::TDK_Underqualified: |
| 833 | case Sema::TDK_DeducedMismatch: |
| 834 | case Sema::TDK_DeducedMismatchNested: |
| 835 | case Sema::TDK_NonDeducedMismatch: |
| 836 | return &static_cast<DFIArguments*>(Data)->FirstArg; |
| 837 | |
| 838 | // Unhandled |
| 839 | case Sema::TDK_MiscellaneousDeductionFailure: |
| 840 | break; |
| 841 | } |
| 842 | |
| 843 | return nullptr; |
| 844 | } |
| 845 | |
| 846 | const TemplateArgument *DeductionFailureInfo::getSecondArg() { |
| 847 | switch (static_cast<Sema::TemplateDeductionResult>(Result)) { |
| 848 | case Sema::TDK_Success: |
| 849 | case Sema::TDK_Invalid: |
| 850 | case Sema::TDK_InstantiationDepth: |
| 851 | case Sema::TDK_Incomplete: |
| 852 | case Sema::TDK_IncompletePack: |
| 853 | case Sema::TDK_TooManyArguments: |
| 854 | case Sema::TDK_TooFewArguments: |
| 855 | case Sema::TDK_InvalidExplicitArguments: |
| 856 | case Sema::TDK_SubstitutionFailure: |
| 857 | case Sema::TDK_CUDATargetMismatch: |
| 858 | case Sema::TDK_NonDependentConversionFailure: |
| 859 | case Sema::TDK_ConstraintsNotSatisfied: |
| 860 | return nullptr; |
| 861 | |
| 862 | case Sema::TDK_Inconsistent: |
| 863 | case Sema::TDK_Underqualified: |
| 864 | case Sema::TDK_DeducedMismatch: |
| 865 | case Sema::TDK_DeducedMismatchNested: |
| 866 | case Sema::TDK_NonDeducedMismatch: |
| 867 | return &static_cast<DFIArguments*>(Data)->SecondArg; |
| 868 | |
| 869 | // Unhandled |
| 870 | case Sema::TDK_MiscellaneousDeductionFailure: |
| 871 | break; |
| 872 | } |
| 873 | |
| 874 | return nullptr; |
| 875 | } |
| 876 | |
| 877 | llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() { |
| 878 | switch (static_cast<Sema::TemplateDeductionResult>(Result)) { |
| 879 | case Sema::TDK_DeducedMismatch: |
| 880 | case Sema::TDK_DeducedMismatchNested: |
| 881 | return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex; |
| 882 | |
| 883 | default: |
| 884 | return llvm::None; |
| 885 | } |
| 886 | } |
| 887 | |
| 888 | bool OverloadCandidateSet::OperatorRewriteInfo::shouldAddReversed( |
| 889 | OverloadedOperatorKind Op) { |
| 890 | if (!AllowRewrittenCandidates) |
| 891 | return false; |
| 892 | return Op == OO_EqualEqual || Op == OO_Spaceship; |
| 893 | } |
| 894 | |
| 895 | bool OverloadCandidateSet::OperatorRewriteInfo::shouldAddReversed( |
| 896 | ASTContext &Ctx, const FunctionDecl *FD) { |
| 897 | if (!shouldAddReversed(FD->getDeclName().getCXXOverloadedOperator())) |
| 898 | return false; |
| 899 | // Don't bother adding a reversed candidate that can never be a better |
| 900 | // match than the non-reversed version. |
| 901 | return FD->getNumParams() != 2 || |
| 902 | !Ctx.hasSameUnqualifiedType(FD->getParamDecl(0)->getType(), |
| 903 | FD->getParamDecl(1)->getType()) || |
| 904 | FD->hasAttr<EnableIfAttr>(); |
| 905 | } |
| 906 | |
| 907 | void OverloadCandidateSet::destroyCandidates() { |
| 908 | for (iterator i = begin(), e = end(); i != e; ++i) { |
| 909 | for (auto &C : i->Conversions) |
| 910 | C.~ImplicitConversionSequence(); |
| 911 | if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction) |
| 912 | i->DeductionFailure.Destroy(); |
| 913 | } |
| 914 | } |
| 915 | |
| 916 | void OverloadCandidateSet::clear(CandidateSetKind CSK) { |
| 917 | destroyCandidates(); |
| 918 | SlabAllocator.Reset(); |
| 919 | NumInlineBytesUsed = 0; |
| 920 | Candidates.clear(); |
| 921 | Functions.clear(); |
| 922 | Kind = CSK; |
| 923 | } |
| 924 | |
| 925 | namespace { |
| 926 | class UnbridgedCastsSet { |
| 927 | struct Entry { |
| 928 | Expr **Addr; |
| 929 | Expr *Saved; |
| 930 | }; |
| 931 | SmallVector<Entry, 2> Entries; |
| 932 | |
| 933 | public: |
| 934 | void save(Sema &S, Expr *&E) { |
| 935 | assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast))((void)0); |
| 936 | Entry entry = { &E, E }; |
| 937 | Entries.push_back(entry); |
| 938 | E = S.stripARCUnbridgedCast(E); |
| 939 | } |
| 940 | |
| 941 | void restore() { |
| 942 | for (SmallVectorImpl<Entry>::iterator |
| 943 | i = Entries.begin(), e = Entries.end(); i != e; ++i) |
| 944 | *i->Addr = i->Saved; |
| 945 | } |
| 946 | }; |
| 947 | } |
| 948 | |
| 949 | /// checkPlaceholderForOverload - Do any interesting placeholder-like |
| 950 | /// preprocessing on the given expression. |
| 951 | /// |
| 952 | /// \param unbridgedCasts a collection to which to add unbridged casts; |
| 953 | /// without this, they will be immediately diagnosed as errors |
| 954 | /// |
| 955 | /// Return true on unrecoverable error. |
| 956 | static bool |
| 957 | checkPlaceholderForOverload(Sema &S, Expr *&E, |
| 958 | UnbridgedCastsSet *unbridgedCasts = nullptr) { |
| 959 | if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) { |
| 960 | // We can't handle overloaded expressions here because overload |
| 961 | // resolution might reasonably tweak them. |
| 962 | if (placeholder->getKind() == BuiltinType::Overload) return false; |
| 963 | |
| 964 | // If the context potentially accepts unbridged ARC casts, strip |
| 965 | // the unbridged cast and add it to the collection for later restoration. |
| 966 | if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast && |
| 967 | unbridgedCasts) { |
| 968 | unbridgedCasts->save(S, E); |
| 969 | return false; |
| 970 | } |
| 971 | |
| 972 | // Go ahead and check everything else. |
| 973 | ExprResult result = S.CheckPlaceholderExpr(E); |
| 974 | if (result.isInvalid()) |
| 975 | return true; |
| 976 | |
| 977 | E = result.get(); |
| 978 | return false; |
| 979 | } |
| 980 | |
| 981 | // Nothing to do. |
| 982 | return false; |
| 983 | } |
| 984 | |
| 985 | /// checkArgPlaceholdersForOverload - Check a set of call operands for |
| 986 | /// placeholders. |
| 987 | static bool checkArgPlaceholdersForOverload(Sema &S, |
| 988 | MultiExprArg Args, |
| 989 | UnbridgedCastsSet &unbridged) { |
| 990 | for (unsigned i = 0, e = Args.size(); i != e; ++i) |
| 991 | if (checkPlaceholderForOverload(S, Args[i], &unbridged)) |
| 992 | return true; |
| 993 | |
| 994 | return false; |
| 995 | } |
| 996 | |
| 997 | /// Determine whether the given New declaration is an overload of the |
| 998 | /// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if |
| 999 | /// New and Old cannot be overloaded, e.g., if New has the same signature as |
| 1000 | /// some function in Old (C++ 1.3.10) or if the Old declarations aren't |
| 1001 | /// functions (or function templates) at all. When it does return Ovl_Match or |
| 1002 | /// Ovl_NonFunction, MatchedDecl will point to the decl that New cannot be |
| 1003 | /// overloaded with. This decl may be a UsingShadowDecl on top of the underlying |
| 1004 | /// declaration. |
| 1005 | /// |
| 1006 | /// Example: Given the following input: |
| 1007 | /// |
| 1008 | /// void f(int, float); // #1 |
| 1009 | /// void f(int, int); // #2 |
| 1010 | /// int f(int, int); // #3 |
| 1011 | /// |
| 1012 | /// When we process #1, there is no previous declaration of "f", so IsOverload |
| 1013 | /// will not be used. |
| 1014 | /// |
| 1015 | /// When we process #2, Old contains only the FunctionDecl for #1. By comparing |
| 1016 | /// the parameter types, we see that #1 and #2 are overloaded (since they have |
| 1017 | /// different signatures), so this routine returns Ovl_Overload; MatchedDecl is |
| 1018 | /// unchanged. |
| 1019 | /// |
| 1020 | /// When we process #3, Old is an overload set containing #1 and #2. We compare |
| 1021 | /// the signatures of #3 to #1 (they're overloaded, so we do nothing) and then |
| 1022 | /// #3 to #2. Since the signatures of #3 and #2 are identical (return types of |
| 1023 | /// functions are not part of the signature), IsOverload returns Ovl_Match and |
| 1024 | /// MatchedDecl will be set to point to the FunctionDecl for #2. |
| 1025 | /// |
| 1026 | /// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced into a class |
| 1027 | /// by a using declaration. The rules for whether to hide shadow declarations |
| 1028 | /// ignore some properties which otherwise figure into a function template's |
| 1029 | /// signature. |
| 1030 | Sema::OverloadKind |
| 1031 | Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, |
| 1032 | NamedDecl *&Match, bool NewIsUsingDecl) { |
| 1033 | for (LookupResult::iterator I = Old.begin(), E = Old.end(); |
| 1034 | I != E; ++I) { |
| 1035 | NamedDecl *OldD = *I; |
| 1036 | |
| 1037 | bool OldIsUsingDecl = false; |
| 1038 | if (isa<UsingShadowDecl>(OldD)) { |
| 1039 | OldIsUsingDecl = true; |
| 1040 | |
| 1041 | // We can always introduce two using declarations into the same |
| 1042 | // context, even if they have identical signatures. |
| 1043 | if (NewIsUsingDecl) continue; |
| 1044 | |
| 1045 | OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); |
| 1046 | } |
| 1047 | |
| 1048 | // A using-declaration does not conflict with another declaration |
| 1049 | // if one of them is hidden. |
| 1050 | if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I)) |
| 1051 | continue; |
| 1052 | |
| 1053 | // If either declaration was introduced by a using declaration, |
| 1054 | // we'll need to use slightly different rules for matching. |
| 1055 | // Essentially, these rules are the normal rules, except that |
| 1056 | // function templates hide function templates with different |
| 1057 | // return types or template parameter lists. |
| 1058 | bool UseMemberUsingDeclRules = |
| 1059 | (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() && |
| 1060 | !New->getFriendObjectKind(); |
| 1061 | |
| 1062 | if (FunctionDecl *OldF = OldD->getAsFunction()) { |
| 1063 | if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { |
| 1064 | if (UseMemberUsingDeclRules && OldIsUsingDecl) { |
| 1065 | HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); |
| 1066 | continue; |
| 1067 | } |
| 1068 | |
| 1069 | if (!isa<FunctionTemplateDecl>(OldD) && |
| 1070 | !shouldLinkPossiblyHiddenDecl(*I, New)) |
| 1071 | continue; |
| 1072 | |
| 1073 | Match = *I; |
| 1074 | return Ovl_Match; |
| 1075 | } |
| 1076 | |
| 1077 | // Builtins that have custom typechecking or have a reference should |
| 1078 | // not be overloadable or redeclarable. |
| 1079 | if (!getASTContext().canBuiltinBeRedeclared(OldF)) { |
| 1080 | Match = *I; |
| 1081 | return Ovl_NonFunction; |
| 1082 | } |
| 1083 | } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) { |
| 1084 | // We can overload with these, which can show up when doing |
| 1085 | // redeclaration checks for UsingDecls. |
| 1086 | assert(Old.getLookupKind() == LookupUsingDeclName)((void)0); |
| 1087 | } else if (isa<TagDecl>(OldD)) { |
| 1088 | // We can always overload with tags by hiding them. |
| 1089 | } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) { |
| 1090 | // Optimistically assume that an unresolved using decl will |
| 1091 | // overload; if it doesn't, we'll have to diagnose during |
| 1092 | // template instantiation. |
| 1093 | // |
| 1094 | // Exception: if the scope is dependent and this is not a class |
| 1095 | // member, the using declaration can only introduce an enumerator. |
| 1096 | if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) { |
| 1097 | Match = *I; |
| 1098 | return Ovl_NonFunction; |
| 1099 | } |
| 1100 | } else { |
| 1101 | // (C++ 13p1): |
| 1102 | // Only function declarations can be overloaded; object and type |
| 1103 | // declarations cannot be overloaded. |
| 1104 | Match = *I; |
| 1105 | return Ovl_NonFunction; |
| 1106 | } |
| 1107 | } |
| 1108 | |
| 1109 | // C++ [temp.friend]p1: |
| 1110 | // For a friend function declaration that is not a template declaration: |
| 1111 | // -- if the name of the friend is a qualified or unqualified template-id, |
| 1112 | // [...], otherwise |
| 1113 | // -- if the name of the friend is a qualified-id and a matching |
| 1114 | // non-template function is found in the specified class or namespace, |
| 1115 | // the friend declaration refers to that function, otherwise, |
| 1116 | // -- if the name of the friend is a qualified-id and a matching function |
| 1117 | // template is found in the specified class or namespace, the friend |
| 1118 | // declaration refers to the deduced specialization of that function |
| 1119 | // template, otherwise |
| 1120 | // -- the name shall be an unqualified-id [...] |
| 1121 | // If we get here for a qualified friend declaration, we've just reached the |
| 1122 | // third bullet. If the type of the friend is dependent, skip this lookup |
| 1123 | // until instantiation. |
| 1124 | if (New->getFriendObjectKind() && New->getQualifier() && |
| 1125 | !New->getDescribedFunctionTemplate() && |
| 1126 | !New->getDependentSpecializationInfo() && |
| 1127 | !New->getType()->isDependentType()) { |
| 1128 | LookupResult TemplateSpecResult(LookupResult::Temporary, Old); |
| 1129 | TemplateSpecResult.addAllDecls(Old); |
| 1130 | if (CheckFunctionTemplateSpecialization(New, nullptr, TemplateSpecResult, |
| 1131 | /*QualifiedFriend*/true)) { |
| 1132 | New->setInvalidDecl(); |
| 1133 | return Ovl_Overload; |
| 1134 | } |
| 1135 | |
| 1136 | Match = TemplateSpecResult.getAsSingle<FunctionDecl>(); |
| 1137 | return Ovl_Match; |
| 1138 | } |
| 1139 | |
| 1140 | return Ovl_Overload; |
| 1141 | } |
| 1142 | |
| 1143 | bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, |
| 1144 | bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs, |
| 1145 | bool ConsiderRequiresClauses) { |
| 1146 | // C++ [basic.start.main]p2: This function shall not be overloaded. |
| 1147 | if (New->isMain()) |
| 1148 | return false; |
| 1149 | |
| 1150 | // MSVCRT user defined entry points cannot be overloaded. |
| 1151 | if (New->isMSVCRTEntryPoint()) |
| 1152 | return false; |
| 1153 | |
| 1154 | FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); |
| 1155 | FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); |
| 1156 | |
| 1157 | // C++ [temp.fct]p2: |
| 1158 | // A function template can be overloaded with other function templates |
| 1159 | // and with normal (non-template) functions. |
| 1160 | if ((OldTemplate == nullptr) != (NewTemplate == nullptr)) |
| 1161 | return true; |
| 1162 | |
| 1163 | // Is the function New an overload of the function Old? |
| 1164 | QualType OldQType = Context.getCanonicalType(Old->getType()); |
| 1165 | QualType NewQType = Context.getCanonicalType(New->getType()); |
| 1166 | |
| 1167 | // Compare the signatures (C++ 1.3.10) of the two functions to |
| 1168 | // determine whether they are overloads. If we find any mismatch |
| 1169 | // in the signature, they are overloads. |
| 1170 | |
| 1171 | // If either of these functions is a K&R-style function (no |
| 1172 | // prototype), then we consider them to have matching signatures. |
| 1173 | if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || |
| 1174 | isa<FunctionNoProtoType>(NewQType.getTypePtr())) |
| 1175 | return false; |
| 1176 | |
| 1177 | const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType); |
| 1178 | const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType); |
| 1179 | |
| 1180 | // The signature of a function includes the types of its |
| 1181 | // parameters (C++ 1.3.10), which includes the presence or absence |
| 1182 | // of the ellipsis; see C++ DR 357). |
| 1183 | if (OldQType != NewQType && |
| 1184 | (OldType->getNumParams() != NewType->getNumParams() || |
| 1185 | OldType->isVariadic() != NewType->isVariadic() || |
| 1186 | !FunctionParamTypesAreEqual(OldType, NewType))) |
| 1187 | return true; |
| 1188 | |
| 1189 | // C++ [temp.over.link]p4: |
| 1190 | // The signature of a function template consists of its function |
| 1191 | // signature, its return type and its template parameter list. The names |
| 1192 | // of the template parameters are significant only for establishing the |
| 1193 | // relationship between the template parameters and the rest of the |
| 1194 | // signature. |
| 1195 | // |
| 1196 | // We check the return type and template parameter lists for function |
| 1197 | // templates first; the remaining checks follow. |
| 1198 | // |
| 1199 | // However, we don't consider either of these when deciding whether |
| 1200 | // a member introduced by a shadow declaration is hidden. |
| 1201 | if (!UseMemberUsingDeclRules && NewTemplate && |
| 1202 | (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), |
| 1203 | OldTemplate->getTemplateParameters(), |
| 1204 | false, TPL_TemplateMatch) || |
| 1205 | !Context.hasSameType(Old->getDeclaredReturnType(), |
| 1206 | New->getDeclaredReturnType()))) |
| 1207 | return true; |
| 1208 | |
| 1209 | // If the function is a class member, its signature includes the |
| 1210 | // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. |
| 1211 | // |
| 1212 | // As part of this, also check whether one of the member functions |
| 1213 | // is static, in which case they are not overloads (C++ |
| 1214 | // 13.1p2). While not part of the definition of the signature, |
| 1215 | // this check is important to determine whether these functions |
| 1216 | // can be overloaded. |
| 1217 | CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old); |
| 1218 | CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New); |
| 1219 | if (OldMethod && NewMethod && |
| 1220 | !OldMethod->isStatic() && !NewMethod->isStatic()) { |
| 1221 | if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) { |
| 1222 | if (!UseMemberUsingDeclRules && |
| 1223 | (OldMethod->getRefQualifier() == RQ_None || |
| 1224 | NewMethod->getRefQualifier() == RQ_None)) { |
| 1225 | // C++0x [over.load]p2: |
| 1226 | // - Member function declarations with the same name and the same |
| 1227 | // parameter-type-list as well as member function template |
| 1228 | // declarations with the same name, the same parameter-type-list, and |
| 1229 | // the same template parameter lists cannot be overloaded if any of |
| 1230 | // them, but not all, have a ref-qualifier (8.3.5). |
| 1231 | Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) |
| 1232 | << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); |
| 1233 | Diag(OldMethod->getLocation(), diag::note_previous_declaration); |
| 1234 | } |
| 1235 | return true; |
| 1236 | } |
| 1237 | |
| 1238 | // We may not have applied the implicit const for a constexpr member |
| 1239 | // function yet (because we haven't yet resolved whether this is a static |
| 1240 | // or non-static member function). Add it now, on the assumption that this |
| 1241 | // is a redeclaration of OldMethod. |
| 1242 | auto OldQuals = OldMethod->getMethodQualifiers(); |
| 1243 | auto NewQuals = NewMethod->getMethodQualifiers(); |
| 1244 | if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() && |
| 1245 | !isa<CXXConstructorDecl>(NewMethod)) |
| 1246 | NewQuals.addConst(); |
| 1247 | // We do not allow overloading based off of '__restrict'. |
| 1248 | OldQuals.removeRestrict(); |
| 1249 | NewQuals.removeRestrict(); |
| 1250 | if (OldQuals != NewQuals) |
| 1251 | return true; |
| 1252 | } |
| 1253 | |
| 1254 | // Though pass_object_size is placed on parameters and takes an argument, we |
| 1255 | // consider it to be a function-level modifier for the sake of function |
| 1256 | // identity. Either the function has one or more parameters with |
| 1257 | // pass_object_size or it doesn't. |
| 1258 | if (functionHasPassObjectSizeParams(New) != |
| 1259 | functionHasPassObjectSizeParams(Old)) |
| 1260 | return true; |
| 1261 | |
| 1262 | // enable_if attributes are an order-sensitive part of the signature. |
| 1263 | for (specific_attr_iterator<EnableIfAttr> |
| 1264 | NewI = New->specific_attr_begin<EnableIfAttr>(), |
| 1265 | NewE = New->specific_attr_end<EnableIfAttr>(), |
| 1266 | OldI = Old->specific_attr_begin<EnableIfAttr>(), |
| 1267 | OldE = Old->specific_attr_end<EnableIfAttr>(); |
| 1268 | NewI != NewE || OldI != OldE; ++NewI, ++OldI) { |
| 1269 | if (NewI == NewE || OldI == OldE) |
| 1270 | return true; |
| 1271 | llvm::FoldingSetNodeID NewID, OldID; |
| 1272 | NewI->getCond()->Profile(NewID, Context, true); |
| 1273 | OldI->getCond()->Profile(OldID, Context, true); |
| 1274 | if (NewID != OldID) |
| 1275 | return true; |
| 1276 | } |
| 1277 | |
| 1278 | if (getLangOpts().CUDA && ConsiderCudaAttrs) { |
| 1279 | // Don't allow overloading of destructors. (In theory we could, but it |
| 1280 | // would be a giant change to clang.) |
| 1281 | if (!isa<CXXDestructorDecl>(New)) { |
| 1282 | CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New), |
| 1283 | OldTarget = IdentifyCUDATarget(Old); |
| 1284 | if (NewTarget != CFT_InvalidTarget) { |
| 1285 | assert((OldTarget != CFT_InvalidTarget) &&((void)0) |
| 1286 | "Unexpected invalid target.")((void)0); |
| 1287 | |
| 1288 | // Allow overloading of functions with same signature and different CUDA |
| 1289 | // target attributes. |
| 1290 | if (NewTarget != OldTarget) |
| 1291 | return true; |
| 1292 | } |
| 1293 | } |
| 1294 | } |
| 1295 | |
| 1296 | if (ConsiderRequiresClauses) { |
| 1297 | Expr *NewRC = New->getTrailingRequiresClause(), |
| 1298 | *OldRC = Old->getTrailingRequiresClause(); |
| 1299 | if ((NewRC != nullptr) != (OldRC != nullptr)) |
| 1300 | // RC are most certainly different - these are overloads. |
| 1301 | return true; |
| 1302 | |
| 1303 | if (NewRC) { |
| 1304 | llvm::FoldingSetNodeID NewID, OldID; |
| 1305 | NewRC->Profile(NewID, Context, /*Canonical=*/true); |
| 1306 | OldRC->Profile(OldID, Context, /*Canonical=*/true); |
| 1307 | if (NewID != OldID) |
| 1308 | // RCs are not equivalent - these are overloads. |
| 1309 | return true; |
| 1310 | } |
| 1311 | } |
| 1312 | |
| 1313 | // The signatures match; this is not an overload. |
| 1314 | return false; |
| 1315 | } |
| 1316 | |
| 1317 | /// Tries a user-defined conversion from From to ToType. |
| 1318 | /// |
| 1319 | /// Produces an implicit conversion sequence for when a standard conversion |
| 1320 | /// is not an option. See TryImplicitConversion for more information. |
| 1321 | static ImplicitConversionSequence |
| 1322 | TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType, |
| 1323 | bool SuppressUserConversions, |
| 1324 | AllowedExplicit AllowExplicit, |
| 1325 | bool InOverloadResolution, |
| 1326 | bool CStyle, |
| 1327 | bool AllowObjCWritebackConversion, |
| 1328 | bool AllowObjCConversionOnExplicit) { |
| 1329 | ImplicitConversionSequence ICS; |
| 1330 | |
| 1331 | if (SuppressUserConversions) { |
| 1332 | // We're not in the case above, so there is no conversion that |
| 1333 | // we can perform. |
| 1334 | ICS.setBad(BadConversionSequence::no_conversion, From, ToType); |
| 1335 | return ICS; |
| 1336 | } |
| 1337 | |
| 1338 | // Attempt user-defined conversion. |
| 1339 | OverloadCandidateSet Conversions(From->getExprLoc(), |
| 1340 | OverloadCandidateSet::CSK_Normal); |
| 1341 | switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, |
| 1342 | Conversions, AllowExplicit, |
| 1343 | AllowObjCConversionOnExplicit)) { |
| 1344 | case OR_Success: |
| 1345 | case OR_Deleted: |
| 1346 | ICS.setUserDefined(); |
| 1347 | // C++ [over.ics.user]p4: |
| 1348 | // A conversion of an expression of class type to the same class |
| 1349 | // type is given Exact Match rank, and a conversion of an |
| 1350 | // expression of class type to a base class of that type is |
| 1351 | // given Conversion rank, in spite of the fact that a copy |
| 1352 | // constructor (i.e., a user-defined conversion function) is |
| 1353 | // called for those cases. |
| 1354 | if (CXXConstructorDecl *Constructor |
| 1355 | = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { |
| 1356 | QualType FromCanon |
| 1357 | = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); |
| 1358 | QualType ToCanon |
| 1359 | = S.Context.getCanonicalType(ToType).getUnqualifiedType(); |
| 1360 | if (Constructor->isCopyConstructor() && |
| 1361 | (FromCanon == ToCanon || |
| 1362 | S.IsDerivedFrom(From->getBeginLoc(), FromCanon, ToCanon))) { |
| 1363 | // Turn this into a "standard" conversion sequence, so that it |
| 1364 | // gets ranked with standard conversion sequences. |
| 1365 | DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction; |
| 1366 | ICS.setStandard(); |
| 1367 | ICS.Standard.setAsIdentityConversion(); |
| 1368 | ICS.Standard.setFromType(From->getType()); |
| 1369 | ICS.Standard.setAllToTypes(ToType); |
| 1370 | ICS.Standard.CopyConstructor = Constructor; |
| 1371 | ICS.Standard.FoundCopyConstructor = Found; |
| 1372 | if (ToCanon != FromCanon) |
| 1373 | ICS.Standard.Second = ICK_Derived_To_Base; |
| 1374 | } |
| 1375 | } |
| 1376 | break; |
| 1377 | |
| 1378 | case OR_Ambiguous: |
| 1379 | ICS.setAmbiguous(); |
| 1380 | ICS.Ambiguous.setFromType(From->getType()); |
| 1381 | ICS.Ambiguous.setToType(ToType); |
| 1382 | for (OverloadCandidateSet::iterator Cand = Conversions.begin(); |
| 1383 | Cand != Conversions.end(); ++Cand) |
| 1384 | if (Cand->Best) |
| 1385 | ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function); |
| 1386 | break; |
| 1387 | |
| 1388 | // Fall through. |
| 1389 | case OR_No_Viable_Function: |
| 1390 | ICS.setBad(BadConversionSequence::no_conversion, From, ToType); |
| 1391 | break; |
| 1392 | } |
| 1393 | |
| 1394 | return ICS; |
| 1395 | } |
| 1396 | |
| 1397 | /// TryImplicitConversion - Attempt to perform an implicit conversion |
| 1398 | /// from the given expression (Expr) to the given type (ToType). This |
| 1399 | /// function returns an implicit conversion sequence that can be used |
| 1400 | /// to perform the initialization. Given |
| 1401 | /// |
| 1402 | /// void f(float f); |
| 1403 | /// void g(int i) { f(i); } |
| 1404 | /// |
| 1405 | /// this routine would produce an implicit conversion sequence to |
| 1406 | /// describe the initialization of f from i, which will be a standard |
| 1407 | /// conversion sequence containing an lvalue-to-rvalue conversion (C++ |
| 1408 | /// 4.1) followed by a floating-integral conversion (C++ 4.9). |
| 1409 | // |
| 1410 | /// Note that this routine only determines how the conversion can be |
| 1411 | /// performed; it does not actually perform the conversion. As such, |
| 1412 | /// it will not produce any diagnostics if no conversion is available, |
| 1413 | /// but will instead return an implicit conversion sequence of kind |
| 1414 | /// "BadConversion". |
| 1415 | /// |
| 1416 | /// If @p SuppressUserConversions, then user-defined conversions are |
| 1417 | /// not permitted. |
| 1418 | /// If @p AllowExplicit, then explicit user-defined conversions are |
| 1419 | /// permitted. |
| 1420 | /// |
| 1421 | /// \param AllowObjCWritebackConversion Whether we allow the Objective-C |
| 1422 | /// writeback conversion, which allows __autoreleasing id* parameters to |
| 1423 | /// be initialized with __strong id* or __weak id* arguments. |
| 1424 | static ImplicitConversionSequence |
| 1425 | TryImplicitConversion(Sema &S, Expr *From, QualType ToType, |
| 1426 | bool SuppressUserConversions, |
| 1427 | AllowedExplicit AllowExplicit, |
| 1428 | bool InOverloadResolution, |
| 1429 | bool CStyle, |
| 1430 | bool AllowObjCWritebackConversion, |
| 1431 | bool AllowObjCConversionOnExplicit) { |
| 1432 | ImplicitConversionSequence ICS; |
| 1433 | if (IsStandardConversion(S, From, ToType, InOverloadResolution, |
| 1434 | ICS.Standard, CStyle, AllowObjCWritebackConversion)){ |
| 1435 | ICS.setStandard(); |
| 1436 | return ICS; |
| 1437 | } |
| 1438 | |
| 1439 | if (!S.getLangOpts().CPlusPlus) { |
| 1440 | ICS.setBad(BadConversionSequence::no_conversion, From, ToType); |
| 1441 | return ICS; |
| 1442 | } |
| 1443 | |
| 1444 | // C++ [over.ics.user]p4: |
| 1445 | // A conversion of an expression of class type to the same class |
| 1446 | // type is given Exact Match rank, and a conversion of an |
| 1447 | // expression of class type to a base class of that type is |
| 1448 | // given Conversion rank, in spite of the fact that a copy/move |
| 1449 | // constructor (i.e., a user-defined conversion function) is |
| 1450 | // called for those cases. |
| 1451 | QualType FromType = From->getType(); |
| 1452 | if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && |
| 1453 | (S.Context.hasSameUnqualifiedType(FromType, ToType) || |
| 1454 | S.IsDerivedFrom(From->getBeginLoc(), FromType, ToType))) { |
| 1455 | ICS.setStandard(); |
| 1456 | ICS.Standard.setAsIdentityConversion(); |
| 1457 | ICS.Standard.setFromType(FromType); |
| 1458 | ICS.Standard.setAllToTypes(ToType); |
| 1459 | |
| 1460 | // We don't actually check at this point whether there is a valid |
| 1461 | // copy/move constructor, since overloading just assumes that it |
| 1462 | // exists. When we actually perform initialization, we'll find the |
| 1463 | // appropriate constructor to copy the returned object, if needed. |
| 1464 | ICS.Standard.CopyConstructor = nullptr; |
| 1465 | |
| 1466 | // Determine whether this is considered a derived-to-base conversion. |
| 1467 | if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) |
| 1468 | ICS.Standard.Second = ICK_Derived_To_Base; |
| 1469 | |
| 1470 | return ICS; |
| 1471 | } |
| 1472 | |
| 1473 | return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, |
| 1474 | AllowExplicit, InOverloadResolution, CStyle, |
| 1475 | AllowObjCWritebackConversion, |
| 1476 | AllowObjCConversionOnExplicit); |
| 1477 | } |
| 1478 | |
| 1479 | ImplicitConversionSequence |
| 1480 | Sema::TryImplicitConversion(Expr *From, QualType ToType, |
| 1481 | bool SuppressUserConversions, |
| 1482 | AllowedExplicit AllowExplicit, |
| 1483 | bool InOverloadResolution, |
| 1484 | bool CStyle, |
| 1485 | bool AllowObjCWritebackConversion) { |
| 1486 | return ::TryImplicitConversion(*this, From, ToType, SuppressUserConversions, |
| 1487 | AllowExplicit, InOverloadResolution, CStyle, |
| 1488 | AllowObjCWritebackConversion, |
| 1489 | /*AllowObjCConversionOnExplicit=*/false); |
| 1490 | } |
| 1491 | |
| 1492 | /// PerformImplicitConversion - Perform an implicit conversion of the |
| 1493 | /// expression From to the type ToType. Returns the |
| 1494 | /// converted expression. Flavor is the kind of conversion we're |
| 1495 | /// performing, used in the error message. If @p AllowExplicit, |
| 1496 | /// explicit user-defined conversions are permitted. |
| 1497 | ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType, |
| 1498 | AssignmentAction Action, |
| 1499 | bool AllowExplicit) { |
| 1500 | if (checkPlaceholderForOverload(*this, From)) |
| 1501 | return ExprError(); |
| 1502 | |
| 1503 | // Objective-C ARC: Determine whether we will allow the writeback conversion. |
| 1504 | bool AllowObjCWritebackConversion |
| 1505 | = getLangOpts().ObjCAutoRefCount && |
| 1506 | (Action == AA_Passing || Action == AA_Sending); |
| 1507 | if (getLangOpts().ObjC) |
| 1508 | CheckObjCBridgeRelatedConversions(From->getBeginLoc(), ToType, |
| 1509 | From->getType(), From); |
| 1510 | ImplicitConversionSequence ICS = ::TryImplicitConversion( |
| 1511 | *this, From, ToType, |
| 1512 | /*SuppressUserConversions=*/false, |
| 1513 | AllowExplicit ? AllowedExplicit::All : AllowedExplicit::None, |
| 1514 | /*InOverloadResolution=*/false, |
| 1515 | /*CStyle=*/false, AllowObjCWritebackConversion, |
| 1516 | /*AllowObjCConversionOnExplicit=*/false); |
| 1517 | return PerformImplicitConversion(From, ToType, ICS, Action); |
| 1518 | } |
| 1519 | |
| 1520 | /// Determine whether the conversion from FromType to ToType is a valid |
| 1521 | /// conversion that strips "noexcept" or "noreturn" off the nested function |
| 1522 | /// type. |
| 1523 | bool Sema::IsFunctionConversion(QualType FromType, QualType ToType, |
| 1524 | QualType &ResultTy) { |
| 1525 | if (Context.hasSameUnqualifiedType(FromType, ToType)) |
| 1526 | return false; |
| 1527 | |
| 1528 | // Permit the conversion F(t __attribute__((noreturn))) -> F(t) |
| 1529 | // or F(t noexcept) -> F(t) |
| 1530 | // where F adds one of the following at most once: |
| 1531 | // - a pointer |
| 1532 | // - a member pointer |
| 1533 | // - a block pointer |
| 1534 | // Changes here need matching changes in FindCompositePointerType. |
| 1535 | CanQualType CanTo = Context.getCanonicalType(ToType); |
| 1536 | CanQualType CanFrom = Context.getCanonicalType(FromType); |
| 1537 | Type::TypeClass TyClass = CanTo->getTypeClass(); |
| 1538 | if (TyClass != CanFrom->getTypeClass()) return false; |
| 1539 | if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { |
| 1540 | if (TyClass == Type::Pointer) { |
| 1541 | CanTo = CanTo.castAs<PointerType>()->getPointeeType(); |
| 1542 | CanFrom = CanFrom.castAs<PointerType>()->getPointeeType(); |
| 1543 | } else if (TyClass == Type::BlockPointer) { |
| 1544 | CanTo = CanTo.castAs<BlockPointerType>()->getPointeeType(); |
| 1545 | CanFrom = CanFrom.castAs<BlockPointerType>()->getPointeeType(); |
| 1546 | } else if (TyClass == Type::MemberPointer) { |
| 1547 | auto ToMPT = CanTo.castAs<MemberPointerType>(); |
| 1548 | auto FromMPT = CanFrom.castAs<MemberPointerType>(); |
| 1549 | // A function pointer conversion cannot change the class of the function. |
| 1550 | if (ToMPT->getClass() != FromMPT->getClass()) |
| 1551 | return false; |
| 1552 | CanTo = ToMPT->getPointeeType(); |
| 1553 | CanFrom = FromMPT->getPointeeType(); |
| 1554 | } else { |
| 1555 | return false; |
| 1556 | } |
| 1557 | |
| 1558 | TyClass = CanTo->getTypeClass(); |
| 1559 | if (TyClass != CanFrom->getTypeClass()) return false; |
| 1560 | if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) |
| 1561 | return false; |
| 1562 | } |
| 1563 | |
| 1564 | const auto *FromFn = cast<FunctionType>(CanFrom); |
| 1565 | FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo(); |
| 1566 | |
| 1567 | const auto *ToFn = cast<FunctionType>(CanTo); |
| 1568 | FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo(); |
| 1569 | |
| 1570 | bool Changed = false; |
| 1571 | |
| 1572 | // Drop 'noreturn' if not present in target type. |
| 1573 | if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) { |
| 1574 | FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false)); |
| 1575 | Changed = true; |
| 1576 | } |
| 1577 | |
| 1578 | // Drop 'noexcept' if not present in target type. |
| 1579 | if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) { |
| 1580 | const auto *ToFPT = cast<FunctionProtoType>(ToFn); |
| 1581 | if (FromFPT->isNothrow() && !ToFPT->isNothrow()) { |
| 1582 | FromFn = cast<FunctionType>( |
| 1583 | Context.getFunctionTypeWithExceptionSpec(QualType(FromFPT, 0), |
| 1584 | EST_None) |
| 1585 | .getTypePtr()); |
| 1586 | Changed = true; |
| 1587 | } |
| 1588 | |
| 1589 | // Convert FromFPT's ExtParameterInfo if necessary. The conversion is valid |
| 1590 | // only if the ExtParameterInfo lists of the two function prototypes can be |
| 1591 | // merged and the merged list is identical to ToFPT's ExtParameterInfo list. |
| 1592 | SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos; |
| 1593 | bool CanUseToFPT, CanUseFromFPT; |
| 1594 | if (Context.mergeExtParameterInfo(ToFPT, FromFPT, CanUseToFPT, |
| 1595 | CanUseFromFPT, NewParamInfos) && |
| 1596 | CanUseToFPT && !CanUseFromFPT) { |
| 1597 | FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo(); |
| 1598 | ExtInfo.ExtParameterInfos = |
| 1599 | NewParamInfos.empty() ? nullptr : NewParamInfos.data(); |
| 1600 | QualType QT = Context.getFunctionType(FromFPT->getReturnType(), |
| 1601 | FromFPT->getParamTypes(), ExtInfo); |
| 1602 | FromFn = QT->getAs<FunctionType>(); |
| 1603 | Changed = true; |
| 1604 | } |
| 1605 | } |
| 1606 | |
| 1607 | if (!Changed) |
| 1608 | return false; |
| 1609 | |
| 1610 | assert(QualType(FromFn, 0).isCanonical())((void)0); |
| 1611 | if (QualType(FromFn, 0) != CanTo) return false; |
| 1612 | |
| 1613 | ResultTy = ToType; |
| 1614 | return true; |
| 1615 | } |
| 1616 | |
| 1617 | /// Determine whether the conversion from FromType to ToType is a valid |
| 1618 | /// vector conversion. |
| 1619 | /// |
| 1620 | /// \param ICK Will be set to the vector conversion kind, if this is a vector |
| 1621 | /// conversion. |
| 1622 | static bool IsVectorConversion(Sema &S, QualType FromType, |
| 1623 | QualType ToType, ImplicitConversionKind &ICK) { |
| 1624 | // We need at least one of these types to be a vector type to have a vector |
| 1625 | // conversion. |
| 1626 | if (!ToType->isVectorType() && !FromType->isVectorType()) |
| 1627 | return false; |
| 1628 | |
| 1629 | // Identical types require no conversions. |
| 1630 | if (S.Context.hasSameUnqualifiedType(FromType, ToType)) |
| 1631 | return false; |
| 1632 | |
| 1633 | // There are no conversions between extended vector types, only identity. |
| 1634 | if (ToType->isExtVectorType()) { |
| 1635 | // There are no conversions between extended vector types other than the |
| 1636 | // identity conversion. |
| 1637 | if (FromType->isExtVectorType()) |
| 1638 | return false; |
| 1639 | |
| 1640 | // Vector splat from any arithmetic type to a vector. |
| 1641 | if (FromType->isArithmeticType()) { |
| 1642 | ICK = ICK_Vector_Splat; |
| 1643 | return true; |
| 1644 | } |
| 1645 | } |
| 1646 | |
| 1647 | if (ToType->isSizelessBuiltinType() || FromType->isSizelessBuiltinType()) |
| 1648 | if (S.Context.areCompatibleSveTypes(FromType, ToType) || |
| 1649 | S.Context.areLaxCompatibleSveTypes(FromType, ToType)) { |
| 1650 | ICK = ICK_SVE_Vector_Conversion; |
| 1651 | return true; |
| 1652 | } |
| 1653 | |
| 1654 | // We can perform the conversion between vector types in the following cases: |
| 1655 | // 1)vector types are equivalent AltiVec and GCC vector types |
| 1656 | // 2)lax vector conversions are permitted and the vector types are of the |
| 1657 | // same size |
| 1658 | // 3)the destination type does not have the ARM MVE strict-polymorphism |
| 1659 | // attribute, which inhibits lax vector conversion for overload resolution |
| 1660 | // only |
| 1661 | if (ToType->isVectorType() && FromType->isVectorType()) { |
| 1662 | if (S.Context.areCompatibleVectorTypes(FromType, ToType) || |
| 1663 | (S.isLaxVectorConversion(FromType, ToType) && |
| 1664 | !ToType->hasAttr(attr::ArmMveStrictPolymorphism))) { |
| 1665 | ICK = ICK_Vector_Conversion; |
| 1666 | return true; |
| 1667 | } |
| 1668 | } |
| 1669 | |
| 1670 | return false; |
| 1671 | } |
| 1672 | |
| 1673 | static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, |
| 1674 | bool InOverloadResolution, |
| 1675 | StandardConversionSequence &SCS, |
| 1676 | bool CStyle); |
| 1677 | |
| 1678 | /// IsStandardConversion - Determines whether there is a standard |
| 1679 | /// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the |
| 1680 | /// expression From to the type ToType. Standard conversion sequences |
| 1681 | /// only consider non-class types; for conversions that involve class |
| 1682 | /// types, use TryImplicitConversion. If a conversion exists, SCS will |
| 1683 | /// contain the standard conversion sequence required to perform this |
| 1684 | /// conversion and this routine will return true. Otherwise, this |
| 1685 | /// routine will return false and the value of SCS is unspecified. |
| 1686 | static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, |
| 1687 | bool InOverloadResolution, |
| 1688 | StandardConversionSequence &SCS, |
| 1689 | bool CStyle, |
| 1690 | bool AllowObjCWritebackConversion) { |
| 1691 | QualType FromType = From->getType(); |
| 1692 | |
| 1693 | // Standard conversions (C++ [conv]) |
| 1694 | SCS.setAsIdentityConversion(); |
| 1695 | SCS.IncompatibleObjC = false; |
| 1696 | SCS.setFromType(FromType); |
| 1697 | SCS.CopyConstructor = nullptr; |
| 1698 | |
| 1699 | // There are no standard conversions for class types in C++, so |
| 1700 | // abort early. When overloading in C, however, we do permit them. |
| 1701 | if (S.getLangOpts().CPlusPlus && |
| 1702 | (FromType->isRecordType() || ToType->isRecordType())) |
| 1703 | return false; |
| 1704 | |
| 1705 | // The first conversion can be an lvalue-to-rvalue conversion, |
| 1706 | // array-to-pointer conversion, or function-to-pointer conversion |
| 1707 | // (C++ 4p1). |
| 1708 | |
| 1709 | if (FromType == S.Context.OverloadTy) { |
| 1710 | DeclAccessPair AccessPair; |
| 1711 | if (FunctionDecl *Fn |
| 1712 | = S.ResolveAddressOfOverloadedFunction(From, ToType, false, |
| 1713 | AccessPair)) { |
| 1714 | // We were able to resolve the address of the overloaded function, |
| 1715 | // so we can convert to the type of that function. |
| 1716 | FromType = Fn->getType(); |
| 1717 | SCS.setFromType(FromType); |
| 1718 | |
| 1719 | // we can sometimes resolve &foo<int> regardless of ToType, so check |
| 1720 | // if the type matches (identity) or we are converting to bool |
| 1721 | if (!S.Context.hasSameUnqualifiedType( |
| 1722 | S.ExtractUnqualifiedFunctionType(ToType), FromType)) { |
| 1723 | QualType resultTy; |
| 1724 | // if the function type matches except for [[noreturn]], it's ok |
| 1725 | if (!S.IsFunctionConversion(FromType, |
| 1726 | S.ExtractUnqualifiedFunctionType(ToType), resultTy)) |
| 1727 | // otherwise, only a boolean conversion is standard |
| 1728 | if (!ToType->isBooleanType()) |
| 1729 | return false; |
| 1730 | } |
| 1731 | |
| 1732 | // Check if the "from" expression is taking the address of an overloaded |
| 1733 | // function and recompute the FromType accordingly. Take advantage of the |
| 1734 | // fact that non-static member functions *must* have such an address-of |
| 1735 | // expression. |
| 1736 | CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); |
| 1737 | if (Method && !Method->isStatic()) { |
| 1738 | assert(isa<UnaryOperator>(From->IgnoreParens()) &&((void)0) |
| 1739 | "Non-unary operator on non-static member address")((void)0); |
| 1740 | assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode()((void)0) |
| 1741 | == UO_AddrOf &&((void)0) |
| 1742 | "Non-address-of operator on non-static member address")((void)0); |
| 1743 | const Type *ClassType |
| 1744 | = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); |
| 1745 | FromType = S.Context.getMemberPointerType(FromType, ClassType); |
| 1746 | } else if (isa<UnaryOperator>(From->IgnoreParens())) { |
| 1747 | assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() ==((void)0) |
| 1748 | UO_AddrOf &&((void)0) |
| 1749 | "Non-address-of operator for overloaded function expression")((void)0); |
| 1750 | FromType = S.Context.getPointerType(FromType); |
| 1751 | } |
| 1752 | |
| 1753 | // Check that we've computed the proper type after overload resolution. |
| 1754 | // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't |
| 1755 | // be calling it from within an NDEBUG block. |
| 1756 | assert(S.Context.hasSameType(((void)0) |
| 1757 | FromType,((void)0) |
| 1758 | S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()))((void)0); |
| 1759 | } else { |
| 1760 | return false; |
| 1761 | } |
| 1762 | } |
| 1763 | // Lvalue-to-rvalue conversion (C++11 4.1): |
| 1764 | // A glvalue (3.10) of a non-function, non-array type T can |
| 1765 | // be converted to a prvalue. |
| 1766 | bool argIsLValue = From->isGLValue(); |
| 1767 | if (argIsLValue && |
| 1768 | !FromType->isFunctionType() && !FromType->isArrayType() && |
| 1769 | S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { |
| 1770 | SCS.First = ICK_Lvalue_To_Rvalue; |
| 1771 | |
| 1772 | // C11 6.3.2.1p2: |
| 1773 | // ... if the lvalue has atomic type, the value has the non-atomic version |
| 1774 | // of the type of the lvalue ... |
| 1775 | if (const AtomicType *Atomic = FromType->getAs<AtomicType>()) |
| 1776 | FromType = Atomic->getValueType(); |
| 1777 | |
| 1778 | // If T is a non-class type, the type of the rvalue is the |
| 1779 | // cv-unqualified version of T. Otherwise, the type of the rvalue |
| 1780 | // is T (C++ 4.1p1). C++ can't get here with class types; in C, we |
| 1781 | // just strip the qualifiers because they don't matter. |
| 1782 | FromType = FromType.getUnqualifiedType(); |
| 1783 | } else if (FromType->isArrayType()) { |
| 1784 | // Array-to-pointer conversion (C++ 4.2) |
| 1785 | SCS.First = ICK_Array_To_Pointer; |
| 1786 | |
| 1787 | // An lvalue or rvalue of type "array of N T" or "array of unknown |
| 1788 | // bound of T" can be converted to an rvalue of type "pointer to |
| 1789 | // T" (C++ 4.2p1). |
| 1790 | FromType = S.Context.getArrayDecayedType(FromType); |
| 1791 | |
| 1792 | if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { |
| 1793 | // This conversion is deprecated in C++03 (D.4) |
| 1794 | SCS.DeprecatedStringLiteralToCharPtr = true; |
| 1795 | |
| 1796 | // For the purpose of ranking in overload resolution |
| 1797 | // (13.3.3.1.1), this conversion is considered an |
| 1798 | // array-to-pointer conversion followed by a qualification |
| 1799 | // conversion (4.4). (C++ 4.2p2) |
| 1800 | SCS.Second = ICK_Identity; |
| 1801 | SCS.Third = ICK_Qualification; |
| 1802 | SCS.QualificationIncludesObjCLifetime = false; |
| 1803 | SCS.setAllToTypes(FromType); |
| 1804 | return true; |
| 1805 | } |
| 1806 | } else if (FromType->isFunctionType() && argIsLValue) { |
| 1807 | // Function-to-pointer conversion (C++ 4.3). |
| 1808 | SCS.First = ICK_Function_To_Pointer; |
| 1809 | |
| 1810 | if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts())) |
| 1811 | if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) |
| 1812 | if (!S.checkAddressOfFunctionIsAvailable(FD)) |
| 1813 | return false; |
| 1814 | |
| 1815 | // An lvalue of function type T can be converted to an rvalue of |
| 1816 | // type "pointer to T." The result is a pointer to the |
| 1817 | // function. (C++ 4.3p1). |
| 1818 | FromType = S.Context.getPointerType(FromType); |
| 1819 | } else { |
| 1820 | // We don't require any conversions for the first step. |
| 1821 | SCS.First = ICK_Identity; |
| 1822 | } |
| 1823 | SCS.setToType(0, FromType); |
| 1824 | |
| 1825 | // The second conversion can be an integral promotion, floating |
| 1826 | // point promotion, integral conversion, floating point conversion, |
| 1827 | // floating-integral conversion, pointer conversion, |
| 1828 | // pointer-to-member conversion, or boolean conversion (C++ 4p1). |
| 1829 | // For overloading in C, this can also be a "compatible-type" |
| 1830 | // conversion. |
| 1831 | bool IncompatibleObjC = false; |
| 1832 | ImplicitConversionKind SecondICK = ICK_Identity; |
| 1833 | if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { |
| 1834 | // The unqualified versions of the types are the same: there's no |
| 1835 | // conversion to do. |
| 1836 | SCS.Second = ICK_Identity; |
| 1837 | } else if (S.IsIntegralPromotion(From, FromType, ToType)) { |
| 1838 | // Integral promotion (C++ 4.5). |
| 1839 | SCS.Second = ICK_Integral_Promotion; |
| 1840 | FromType = ToType.getUnqualifiedType(); |
| 1841 | } else if (S.IsFloatingPointPromotion(FromType, ToType)) { |
| 1842 | // Floating point promotion (C++ 4.6). |
| 1843 | SCS.Second = ICK_Floating_Promotion; |
| 1844 | FromType = ToType.getUnqualifiedType(); |
| 1845 | } else if (S.IsComplexPromotion(FromType, ToType)) { |
| 1846 | // Complex promotion (Clang extension) |
| 1847 | SCS.Second = ICK_Complex_Promotion; |
| 1848 | FromType = ToType.getUnqualifiedType(); |
| 1849 | } else if (ToType->isBooleanType() && |
| 1850 | (FromType->isArithmeticType() || |
| 1851 | FromType->isAnyPointerType() || |
| 1852 | FromType->isBlockPointerType() || |
| 1853 | FromType->isMemberPointerType())) { |
| 1854 | // Boolean conversions (C++ 4.12). |
| 1855 | SCS.Second = ICK_Boolean_Conversion; |
| 1856 | FromType = S.Context.BoolTy; |
| 1857 | } else if (FromType->isIntegralOrUnscopedEnumerationType() && |
| 1858 | ToType->isIntegralType(S.Context)) { |
| 1859 | // Integral conversions (C++ 4.7). |
| 1860 | SCS.Second = ICK_Integral_Conversion; |
| 1861 | FromType = ToType.getUnqualifiedType(); |
| 1862 | } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) { |
| 1863 | // Complex conversions (C99 6.3.1.6) |
| 1864 | SCS.Second = ICK_Complex_Conversion; |
| 1865 | FromType = ToType.getUnqualifiedType(); |
| 1866 | } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || |
| 1867 | (ToType->isAnyComplexType() && FromType->isArithmeticType())) { |
| 1868 | // Complex-real conversions (C99 6.3.1.7) |
| 1869 | SCS.Second = ICK_Complex_Real; |
| 1870 | FromType = ToType.getUnqualifiedType(); |
| 1871 | } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { |
| 1872 | // FIXME: disable conversions between long double and __float128 if |
| 1873 | // their representation is different until there is back end support |
| 1874 | // We of course allow this conversion if long double is really double. |
| 1875 | |
| 1876 | // Conversions between bfloat and other floats are not permitted. |
| 1877 | if (FromType == S.Context.BFloat16Ty || ToType == S.Context.BFloat16Ty) |
| 1878 | return false; |
| 1879 | if (&S.Context.getFloatTypeSemantics(FromType) != |
| 1880 | &S.Context.getFloatTypeSemantics(ToType)) { |
| 1881 | bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty && |
| 1882 | ToType == S.Context.LongDoubleTy) || |
| 1883 | (FromType == S.Context.LongDoubleTy && |
| 1884 | ToType == S.Context.Float128Ty)); |
| 1885 | if (Float128AndLongDouble && |
| 1886 | (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) == |
| 1887 | &llvm::APFloat::PPCDoubleDouble())) |
| 1888 | return false; |
| 1889 | } |
| 1890 | // Floating point conversions (C++ 4.8). |
| 1891 | SCS.Second = ICK_Floating_Conversion; |
| 1892 | FromType = ToType.getUnqualifiedType(); |
| 1893 | } else if ((FromType->isRealFloatingType() && |
| 1894 | ToType->isIntegralType(S.Context)) || |
| 1895 | (FromType->isIntegralOrUnscopedEnumerationType() && |
| 1896 | ToType->isRealFloatingType())) { |
| 1897 | // Conversions between bfloat and int are not permitted. |
| 1898 | if (FromType->isBFloat16Type() || ToType->isBFloat16Type()) |
| 1899 | return false; |
| 1900 | |
| 1901 | // Floating-integral conversions (C++ 4.9). |
| 1902 | SCS.Second = ICK_Floating_Integral; |
| 1903 | FromType = ToType.getUnqualifiedType(); |
| 1904 | } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { |
| 1905 | SCS.Second = ICK_Block_Pointer_Conversion; |
| 1906 | } else if (AllowObjCWritebackConversion && |
| 1907 | S.isObjCWritebackConversion(FromType, ToType, FromType)) { |
| 1908 | SCS.Second = ICK_Writeback_Conversion; |
| 1909 | } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, |
| 1910 | FromType, IncompatibleObjC)) { |
| 1911 | // Pointer conversions (C++ 4.10). |
| 1912 | SCS.Second = ICK_Pointer_Conversion; |
| 1913 | SCS.IncompatibleObjC = IncompatibleObjC; |
| 1914 | FromType = FromType.getUnqualifiedType(); |
| 1915 | } else if (S.IsMemberPointerConversion(From, FromType, ToType, |
| 1916 | InOverloadResolution, FromType)) { |
| 1917 | // Pointer to member conversions (4.11). |
| 1918 | SCS.Second = ICK_Pointer_Member; |
| 1919 | } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) { |
| 1920 | SCS.Second = SecondICK; |
| 1921 | FromType = ToType.getUnqualifiedType(); |
| 1922 | } else if (!S.getLangOpts().CPlusPlus && |
| 1923 | S.Context.typesAreCompatible(ToType, FromType)) { |
| 1924 | // Compatible conversions (Clang extension for C function overloading) |
| 1925 | SCS.Second = ICK_Compatible_Conversion; |
| 1926 | FromType = ToType.getUnqualifiedType(); |
| 1927 | } else if (IsTransparentUnionStandardConversion(S, From, ToType, |
| 1928 | InOverloadResolution, |
| 1929 | SCS, CStyle)) { |
| 1930 | SCS.Second = ICK_TransparentUnionConversion; |
| 1931 | FromType = ToType; |
| 1932 | } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS, |
| 1933 | CStyle)) { |
| 1934 | // tryAtomicConversion has updated the standard conversion sequence |
| 1935 | // appropriately. |
| 1936 | return true; |
| 1937 | } else if (ToType->isEventT() && |
| 1938 | From->isIntegerConstantExpr(S.getASTContext()) && |
| 1939 | From->EvaluateKnownConstInt(S.getASTContext()) == 0) { |
| 1940 | SCS.Second = ICK_Zero_Event_Conversion; |
| 1941 | FromType = ToType; |
| 1942 | } else if (ToType->isQueueT() && |
| 1943 | From->isIntegerConstantExpr(S.getASTContext()) && |
| 1944 | (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) { |
| 1945 | SCS.Second = ICK_Zero_Queue_Conversion; |
| 1946 | FromType = ToType; |
| 1947 | } else if (ToType->isSamplerT() && |
| 1948 | From->isIntegerConstantExpr(S.getASTContext())) { |
| 1949 | SCS.Second = ICK_Compatible_Conversion; |
| 1950 | FromType = ToType; |
| 1951 | } else { |
| 1952 | // No second conversion required. |
| 1953 | SCS.Second = ICK_Identity; |
| 1954 | } |
| 1955 | SCS.setToType(1, FromType); |
| 1956 | |
| 1957 | // The third conversion can be a function pointer conversion or a |
| 1958 | // qualification conversion (C++ [conv.fctptr], [conv.qual]). |
| 1959 | bool ObjCLifetimeConversion; |
| 1960 | if (S.IsFunctionConversion(FromType, ToType, FromType)) { |
| 1961 | // Function pointer conversions (removing 'noexcept') including removal of |
| 1962 | // 'noreturn' (Clang extension). |
| 1963 | SCS.Third = ICK_Function_Conversion; |
| 1964 | } else if (S.IsQualificationConversion(FromType, ToType, CStyle, |
| 1965 | ObjCLifetimeConversion)) { |
| 1966 | SCS.Third = ICK_Qualification; |
| 1967 | SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion; |
| 1968 | FromType = ToType; |
| 1969 | } else { |
| 1970 | // No conversion required |
| 1971 | SCS.Third = ICK_Identity; |
| 1972 | } |
| 1973 | |
| 1974 | // C++ [over.best.ics]p6: |
| 1975 | // [...] Any difference in top-level cv-qualification is |
| 1976 | // subsumed by the initialization itself and does not constitute |
| 1977 | // a conversion. [...] |
| 1978 | QualType CanonFrom = S.Context.getCanonicalType(FromType); |
| 1979 | QualType CanonTo = S.Context.getCanonicalType(ToType); |
| 1980 | if (CanonFrom.getLocalUnqualifiedType() |
| 1981 | == CanonTo.getLocalUnqualifiedType() && |
| 1982 | CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) { |
| 1983 | FromType = ToType; |
| 1984 | CanonFrom = CanonTo; |
| 1985 | } |
| 1986 | |
| 1987 | SCS.setToType(2, FromType); |
| 1988 | |
| 1989 | if (CanonFrom == CanonTo) |
| 1990 | return true; |
| 1991 | |
| 1992 | // If we have not converted the argument type to the parameter type, |
| 1993 | // this is a bad conversion sequence, unless we're resolving an overload in C. |
| 1994 | if (S.getLangOpts().CPlusPlus || !InOverloadResolution) |
| 1995 | return false; |
| 1996 | |
| 1997 | ExprResult ER = ExprResult{From}; |
| 1998 | Sema::AssignConvertType Conv = |
| 1999 | S.CheckSingleAssignmentConstraints(ToType, ER, |
| 2000 | /*Diagnose=*/false, |
| 2001 | /*DiagnoseCFAudited=*/false, |
| 2002 | /*ConvertRHS=*/false); |
| 2003 | ImplicitConversionKind SecondConv; |
| 2004 | switch (Conv) { |
| 2005 | case Sema::Compatible: |
| 2006 | SecondConv = ICK_C_Only_Conversion; |
| 2007 | break; |
| 2008 | // For our purposes, discarding qualifiers is just as bad as using an |
| 2009 | // incompatible pointer. Note that an IncompatiblePointer conversion can drop |
| 2010 | // qualifiers, as well. |
| 2011 | case Sema::CompatiblePointerDiscardsQualifiers: |
| 2012 | case Sema::IncompatiblePointer: |
| 2013 | case Sema::IncompatiblePointerSign: |
| 2014 | SecondConv = ICK_Incompatible_Pointer_Conversion; |
| 2015 | break; |
| 2016 | default: |
| 2017 | return false; |
| 2018 | } |
| 2019 | |
| 2020 | // First can only be an lvalue conversion, so we pretend that this was the |
| 2021 | // second conversion. First should already be valid from earlier in the |
| 2022 | // function. |
| 2023 | SCS.Second = SecondConv; |
| 2024 | SCS.setToType(1, ToType); |
| 2025 | |
| 2026 | // Third is Identity, because Second should rank us worse than any other |
| 2027 | // conversion. This could also be ICK_Qualification, but it's simpler to just |
| 2028 | // lump everything in with the second conversion, and we don't gain anything |
| 2029 | // from making this ICK_Qualification. |
| 2030 | SCS.Third = ICK_Identity; |
| 2031 | SCS.setToType(2, ToType); |
| 2032 | return true; |
| 2033 | } |
| 2034 | |
| 2035 | static bool |
| 2036 | IsTransparentUnionStandardConversion(Sema &S, Expr* From, |
| 2037 | QualType &ToType, |
| 2038 | bool InOverloadResolution, |
| 2039 | StandardConversionSequence &SCS, |
| 2040 | bool CStyle) { |
| 2041 | |
| 2042 | const RecordType *UT = ToType->getAsUnionType(); |
| 2043 | if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) |
| 2044 | return false; |
| 2045 | // The field to initialize within the transparent union. |
| 2046 | RecordDecl *UD = UT->getDecl(); |
| 2047 | // It's compatible if the expression matches any of the fields. |
| 2048 | for (const auto *it : UD->fields()) { |
| 2049 | if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, |
| 2050 | CStyle, /*AllowObjCWritebackConversion=*/false)) { |
| 2051 | ToType = it->getType(); |
| 2052 | return true; |
| 2053 | } |
| 2054 | } |
| 2055 | return false; |
| 2056 | } |
| 2057 | |
| 2058 | /// IsIntegralPromotion - Determines whether the conversion from the |
| 2059 | /// expression From (whose potentially-adjusted type is FromType) to |
| 2060 | /// ToType is an integral promotion (C++ 4.5). If so, returns true and |
| 2061 | /// sets PromotedType to the promoted type. |
| 2062 | bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { |
| 2063 | const BuiltinType *To = ToType->getAs<BuiltinType>(); |
| 2064 | // All integers are built-in. |
| 2065 | if (!To) { |
| 2066 | return false; |
| 2067 | } |
| 2068 | |
| 2069 | // An rvalue of type char, signed char, unsigned char, short int, or |
| 2070 | // unsigned short int can be converted to an rvalue of type int if |
| 2071 | // int can represent all the values of the source type; otherwise, |
| 2072 | // the source rvalue can be converted to an rvalue of type unsigned |
| 2073 | // int (C++ 4.5p1). |
| 2074 | if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && |
| 2075 | !FromType->isEnumeralType()) { |
| 2076 | if (// We can promote any signed, promotable integer type to an int |
| 2077 | (FromType->isSignedIntegerType() || |
| 2078 | // We can promote any unsigned integer type whose size is |
| 2079 | // less than int to an int. |
| 2080 | Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) { |
| 2081 | return To->getKind() == BuiltinType::Int; |
| 2082 | } |
| 2083 | |
| 2084 | return To->getKind() == BuiltinType::UInt; |
| 2085 | } |
| 2086 | |
| 2087 | // C++11 [conv.prom]p3: |
| 2088 | // A prvalue of an unscoped enumeration type whose underlying type is not |
| 2089 | // fixed (7.2) can be converted to an rvalue a prvalue of the first of the |
| 2090 | // following types that can represent all the values of the enumeration |
| 2091 | // (i.e., the values in the range bmin to bmax as described in 7.2): int, |
| 2092 | // unsigned int, long int, unsigned long int, long long int, or unsigned |
| 2093 | // long long int. If none of the types in that list can represent all the |
| 2094 | // values of the enumeration, an rvalue a prvalue of an unscoped enumeration |
| 2095 | // type can be converted to an rvalue a prvalue of the extended integer type |
| 2096 | // with lowest integer conversion rank (4.13) greater than the rank of long |
| 2097 | // long in which all the values of the enumeration can be represented. If |
| 2098 | // there are two such extended types, the signed one is chosen. |
| 2099 | // C++11 [conv.prom]p4: |
| 2100 | // A prvalue of an unscoped enumeration type whose underlying type is fixed |
| 2101 | // can be converted to a prvalue of its underlying type. Moreover, if |
| 2102 | // integral promotion can be applied to its underlying type, a prvalue of an |
| 2103 | // unscoped enumeration type whose underlying type is fixed can also be |
| 2104 | // converted to a prvalue of the promoted underlying type. |
| 2105 | if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { |
| 2106 | // C++0x 7.2p9: Note that this implicit enum to int conversion is not |
| 2107 | // provided for a scoped enumeration. |
| 2108 | if (FromEnumType->getDecl()->isScoped()) |
| 2109 | return false; |
| 2110 | |
| 2111 | // We can perform an integral promotion to the underlying type of the enum, |
| 2112 | // even if that's not the promoted type. Note that the check for promoting |
| 2113 | // the underlying type is based on the type alone, and does not consider |
| 2114 | // the bitfield-ness of the actual source expression. |
| 2115 | if (FromEnumType->getDecl()->isFixed()) { |
| 2116 | QualType Underlying = FromEnumType->getDecl()->getIntegerType(); |
| 2117 | return Context.hasSameUnqualifiedType(Underlying, ToType) || |
| 2118 | IsIntegralPromotion(nullptr, Underlying, ToType); |
| 2119 | } |
| 2120 | |
| 2121 | // We have already pre-calculated the promotion type, so this is trivial. |
| 2122 | if (ToType->isIntegerType() && |
| 2123 | isCompleteType(From->getBeginLoc(), FromType)) |
| 2124 | return Context.hasSameUnqualifiedType( |
| 2125 | ToType, FromEnumType->getDecl()->getPromotionType()); |
| 2126 | |
| 2127 | // C++ [conv.prom]p5: |
| 2128 | // If the bit-field has an enumerated type, it is treated as any other |
| 2129 | // value of that type for promotion purposes. |
| 2130 | // |
| 2131 | // ... so do not fall through into the bit-field checks below in C++. |
| 2132 | if (getLangOpts().CPlusPlus) |
| 2133 | return false; |
| 2134 | } |
| 2135 | |
| 2136 | // C++0x [conv.prom]p2: |
| 2137 | // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted |
| 2138 | // to an rvalue a prvalue of the first of the following types that can |
| 2139 | // represent all the values of its underlying type: int, unsigned int, |
| 2140 | // long int, unsigned long int, long long int, or unsigned long long int. |
| 2141 | // If none of the types in that list can represent all the values of its |
| 2142 | // underlying type, an rvalue a prvalue of type char16_t, char32_t, |
| 2143 | // or wchar_t can be converted to an rvalue a prvalue of its underlying |
| 2144 | // type. |
| 2145 | if (FromType->isAnyCharacterType() && !FromType->isCharType() && |
| 2146 | ToType->isIntegerType()) { |
| 2147 | // Determine whether the type we're converting from is signed or |
| 2148 | // unsigned. |
| 2149 | bool FromIsSigned = FromType->isSignedIntegerType(); |
| 2150 | uint64_t FromSize = Context.getTypeSize(FromType); |
| 2151 | |
| 2152 | // The types we'll try to promote to, in the appropriate |
| 2153 | // order. Try each of these types. |
| 2154 | QualType PromoteTypes[6] = { |
| 2155 | Context.IntTy, Context.UnsignedIntTy, |
| 2156 | Context.LongTy, Context.UnsignedLongTy , |
| 2157 | Context.LongLongTy, Context.UnsignedLongLongTy |
| 2158 | }; |
| 2159 | for (int Idx = 0; Idx < 6; ++Idx) { |
| 2160 | uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); |
| 2161 | if (FromSize < ToSize || |
| 2162 | (FromSize == ToSize && |
| 2163 | FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { |
| 2164 | // We found the type that we can promote to. If this is the |
| 2165 | // type we wanted, we have a promotion. Otherwise, no |
| 2166 | // promotion. |
| 2167 | return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); |
| 2168 | } |
| 2169 | } |
| 2170 | } |
| 2171 | |
| 2172 | // An rvalue for an integral bit-field (9.6) can be converted to an |
| 2173 | // rvalue of type int if int can represent all the values of the |
| 2174 | // bit-field; otherwise, it can be converted to unsigned int if |
| 2175 | // unsigned int can represent all the values of the bit-field. If |
| 2176 | // the bit-field is larger yet, no integral promotion applies to |
| 2177 | // it. If the bit-field has an enumerated type, it is treated as any |
| 2178 | // other value of that type for promotion purposes (C++ 4.5p3). |
| 2179 | // FIXME: We should delay checking of bit-fields until we actually perform the |
| 2180 | // conversion. |
| 2181 | // |
| 2182 | // FIXME: In C, only bit-fields of types _Bool, int, or unsigned int may be |
| 2183 | // promoted, per C11 6.3.1.1/2. We promote all bit-fields (including enum |
| 2184 | // bit-fields and those whose underlying type is larger than int) for GCC |
| 2185 | // compatibility. |
| 2186 | if (From) { |
| 2187 | if (FieldDecl *MemberDecl = From->getSourceBitField()) { |
| 2188 | Optional<llvm::APSInt> BitWidth; |
| 2189 | if (FromType->isIntegralType(Context) && |
| 2190 | (BitWidth = |
| 2191 | MemberDecl->getBitWidth()->getIntegerConstantExpr(Context))) { |
| 2192 | llvm::APSInt ToSize(BitWidth->getBitWidth(), BitWidth->isUnsigned()); |
| 2193 | ToSize = Context.getTypeSize(ToType); |
| 2194 | |
| 2195 | // Are we promoting to an int from a bitfield that fits in an int? |
| 2196 | if (*BitWidth < ToSize || |
| 2197 | (FromType->isSignedIntegerType() && *BitWidth <= ToSize)) { |
| 2198 | return To->getKind() == BuiltinType::Int; |
| 2199 | } |
| 2200 | |
| 2201 | // Are we promoting to an unsigned int from an unsigned bitfield |
| 2202 | // that fits into an unsigned int? |
| 2203 | if (FromType->isUnsignedIntegerType() && *BitWidth <= ToSize) { |
| 2204 | return To->getKind() == BuiltinType::UInt; |
| 2205 | } |
| 2206 | |
| 2207 | return false; |
| 2208 | } |
| 2209 | } |
| 2210 | } |
| 2211 | |
| 2212 | // An rvalue of type bool can be converted to an rvalue of type int, |
| 2213 | // with false becoming zero and true becoming one (C++ 4.5p4). |
| 2214 | if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { |
| 2215 | return true; |
| 2216 | } |
| 2217 | |
| 2218 | return false; |
| 2219 | } |
| 2220 | |
| 2221 | /// IsFloatingPointPromotion - Determines whether the conversion from |
| 2222 | /// FromType to ToType is a floating point promotion (C++ 4.6). If so, |
| 2223 | /// returns true and sets PromotedType to the promoted type. |
| 2224 | bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { |
| 2225 | if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) |
| 2226 | if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { |
| 2227 | /// An rvalue of type float can be converted to an rvalue of type |
| 2228 | /// double. (C++ 4.6p1). |
| 2229 | if (FromBuiltin->getKind() == BuiltinType::Float && |
| 2230 | ToBuiltin->getKind() == BuiltinType::Double) |
| 2231 | return true; |
| 2232 | |
| 2233 | // C99 6.3.1.5p1: |
| 2234 | // When a float is promoted to double or long double, or a |
| 2235 | // double is promoted to long double [...]. |
| 2236 | if (!getLangOpts().CPlusPlus && |
| 2237 | (FromBuiltin->getKind() == BuiltinType::Float || |
| 2238 | FromBuiltin->getKind() == BuiltinType::Double) && |
| 2239 | (ToBuiltin->getKind() == BuiltinType::LongDouble || |
| 2240 | ToBuiltin->getKind() == BuiltinType::Float128)) |
| 2241 | return true; |
| 2242 | |
| 2243 | // Half can be promoted to float. |
| 2244 | if (!getLangOpts().NativeHalfType && |
| 2245 | FromBuiltin->getKind() == BuiltinType::Half && |
| 2246 | ToBuiltin->getKind() == BuiltinType::Float) |
| 2247 | return true; |
| 2248 | } |
| 2249 | |
| 2250 | return false; |
| 2251 | } |
| 2252 | |
| 2253 | /// Determine if a conversion is a complex promotion. |
| 2254 | /// |
| 2255 | /// A complex promotion is defined as a complex -> complex conversion |
| 2256 | /// where the conversion between the underlying real types is a |
| 2257 | /// floating-point or integral promotion. |
| 2258 | bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { |
| 2259 | const ComplexType *FromComplex = FromType->getAs<ComplexType>(); |
| 2260 | if (!FromComplex) |
| 2261 | return false; |
| 2262 | |
| 2263 | const ComplexType *ToComplex = ToType->getAs<ComplexType>(); |
| 2264 | if (!ToComplex) |
| 2265 | return false; |
| 2266 | |
| 2267 | return IsFloatingPointPromotion(FromComplex->getElementType(), |
| 2268 | ToComplex->getElementType()) || |
| 2269 | IsIntegralPromotion(nullptr, FromComplex->getElementType(), |
| 2270 | ToComplex->getElementType()); |
| 2271 | } |
| 2272 | |
| 2273 | /// BuildSimilarlyQualifiedPointerType - In a pointer conversion from |
| 2274 | /// the pointer type FromPtr to a pointer to type ToPointee, with the |
| 2275 | /// same type qualifiers as FromPtr has on its pointee type. ToType, |
| 2276 | /// if non-empty, will be a pointer to ToType that may or may not have |
| 2277 | /// the right set of qualifiers on its pointee. |
| 2278 | /// |
| 2279 | static QualType |
| 2280 | BuildSimilarlyQualifiedPointerType(const Type *FromPtr, |
| 2281 | QualType ToPointee, QualType ToType, |
| 2282 | ASTContext &Context, |
| 2283 | bool StripObjCLifetime = false) { |
| 2284 | assert((FromPtr->getTypeClass() == Type::Pointer ||((void)0) |
| 2285 | FromPtr->getTypeClass() == Type::ObjCObjectPointer) &&((void)0) |
| 2286 | "Invalid similarly-qualified pointer type")((void)0); |
| 2287 | |
| 2288 | /// Conversions to 'id' subsume cv-qualifier conversions. |
| 2289 | if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) |
| 2290 | return ToType.getUnqualifiedType(); |
| 2291 | |
| 2292 | QualType CanonFromPointee |
| 2293 | = Context.getCanonicalType(FromPtr->getPointeeType()); |
| 2294 | QualType CanonToPointee = Context.getCanonicalType(ToPointee); |
| 2295 | Qualifiers Quals = CanonFromPointee.getQualifiers(); |
| 2296 | |
| 2297 | if (StripObjCLifetime) |
| 2298 | Quals.removeObjCLifetime(); |
| 2299 | |
| 2300 | // Exact qualifier match -> return the pointer type we're converting to. |
| 2301 | if (CanonToPointee.getLocalQualifiers() == Quals) { |
| 2302 | // ToType is exactly what we need. Return it. |
| 2303 | if (!ToType.isNull()) |
| 2304 | return ToType.getUnqualifiedType(); |
| 2305 | |
| 2306 | // Build a pointer to ToPointee. It has the right qualifiers |
| 2307 | // already. |
| 2308 | if (isa<ObjCObjectPointerType>(ToType)) |
| 2309 | return Context.getObjCObjectPointerType(ToPointee); |
| 2310 | return Context.getPointerType(ToPointee); |
| 2311 | } |
| 2312 | |
| 2313 | // Just build a canonical type that has the right qualifiers. |
| 2314 | QualType QualifiedCanonToPointee |
| 2315 | = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); |
| 2316 | |
| 2317 | if (isa<ObjCObjectPointerType>(ToType)) |
| 2318 | return Context.getObjCObjectPointerType(QualifiedCanonToPointee); |
| 2319 | return Context.getPointerType(QualifiedCanonToPointee); |
| 2320 | } |
| 2321 | |
| 2322 | static bool isNullPointerConstantForConversion(Expr *Expr, |
| 2323 | bool InOverloadResolution, |
| 2324 | ASTContext &Context) { |
| 2325 | // Handle value-dependent integral null pointer constants correctly. |
| 2326 | // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 |
| 2327 | if (Expr->isValueDependent() && !Expr->isTypeDependent() && |
| 2328 | Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) |
| 2329 | return !InOverloadResolution; |
| 2330 | |
| 2331 | return Expr->isNullPointerConstant(Context, |
| 2332 | InOverloadResolution? Expr::NPC_ValueDependentIsNotNull |
| 2333 | : Expr::NPC_ValueDependentIsNull); |
| 2334 | } |
| 2335 | |
| 2336 | /// IsPointerConversion - Determines whether the conversion of the |
| 2337 | /// expression From, which has the (possibly adjusted) type FromType, |
| 2338 | /// can be converted to the type ToType via a pointer conversion (C++ |
| 2339 | /// 4.10). If so, returns true and places the converted type (that |
| 2340 | /// might differ from ToType in its cv-qualifiers at some level) into |
| 2341 | /// ConvertedType. |
| 2342 | /// |
| 2343 | /// This routine also supports conversions to and from block pointers |
| 2344 | /// and conversions with Objective-C's 'id', 'id<protocols...>', and |
| 2345 | /// pointers to interfaces. FIXME: Once we've determined the |
| 2346 | /// appropriate overloading rules for Objective-C, we may want to |
| 2347 | /// split the Objective-C checks into a different routine; however, |
| 2348 | /// GCC seems to consider all of these conversions to be pointer |
| 2349 | /// conversions, so for now they live here. IncompatibleObjC will be |
| 2350 | /// set if the conversion is an allowed Objective-C conversion that |
| 2351 | /// should result in a warning. |
| 2352 | bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, |
| 2353 | bool InOverloadResolution, |
| 2354 | QualType& ConvertedType, |
| 2355 | bool &IncompatibleObjC) { |
| 2356 | IncompatibleObjC = false; |
| 2357 | if (isObjCPointerConversion(FromType, ToType, ConvertedType, |
| 2358 | IncompatibleObjC)) |
| 2359 | return true; |
| 2360 | |
| 2361 | // Conversion from a null pointer constant to any Objective-C pointer type. |
| 2362 | if (ToType->isObjCObjectPointerType() && |
| 2363 | isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { |
| 2364 | ConvertedType = ToType; |
| 2365 | return true; |
| 2366 | } |
| 2367 | |
| 2368 | // Blocks: Block pointers can be converted to void*. |
| 2369 | if (FromType->isBlockPointerType() && ToType->isPointerType() && |
| 2370 | ToType->castAs<PointerType>()->getPointeeType()->isVoidType()) { |
| 2371 | ConvertedType = ToType; |
| 2372 | return true; |
| 2373 | } |
| 2374 | // Blocks: A null pointer constant can be converted to a block |
| 2375 | // pointer type. |
| 2376 | if (ToType->isBlockPointerType() && |
| 2377 | isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { |
| 2378 | ConvertedType = ToType; |
| 2379 | return true; |
| 2380 | } |
| 2381 | |
| 2382 | // If the left-hand-side is nullptr_t, the right side can be a null |
| 2383 | // pointer constant. |
| 2384 | if (ToType->isNullPtrType() && |
| 2385 | isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { |
| 2386 | ConvertedType = ToType; |
| 2387 | return true; |
| 2388 | } |
| 2389 | |
| 2390 | const PointerType* ToTypePtr = ToType->getAs<PointerType>(); |
| 2391 | if (!ToTypePtr) |
| 2392 | return false; |
| 2393 | |
| 2394 | // A null pointer constant can be converted to a pointer type (C++ 4.10p1). |
| 2395 | if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { |
| 2396 | ConvertedType = ToType; |
| 2397 | return true; |
| 2398 | } |
| 2399 | |
| 2400 | // Beyond this point, both types need to be pointers |
| 2401 | // , including objective-c pointers. |
| 2402 | QualType ToPointeeType = ToTypePtr->getPointeeType(); |
| 2403 | if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() && |
| 2404 | !getLangOpts().ObjCAutoRefCount) { |
| 2405 | ConvertedType = BuildSimilarlyQualifiedPointerType( |
| 2406 | FromType->getAs<ObjCObjectPointerType>(), |
| 2407 | ToPointeeType, |
| 2408 | ToType, Context); |
| 2409 | return true; |
| 2410 | } |
| 2411 | const PointerType *FromTypePtr = FromType->getAs<PointerType>(); |
| 2412 | if (!FromTypePtr) |
| 2413 | return false; |
| 2414 | |
| 2415 | QualType FromPointeeType = FromTypePtr->getPointeeType(); |
| 2416 | |
| 2417 | // If the unqualified pointee types are the same, this can't be a |
| 2418 | // pointer conversion, so don't do all of the work below. |
| 2419 | if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) |
| 2420 | return false; |
| 2421 | |
| 2422 | // An rvalue of type "pointer to cv T," where T is an object type, |
| 2423 | // can be converted to an rvalue of type "pointer to cv void" (C++ |
| 2424 | // 4.10p2). |
| 2425 | if (FromPointeeType->isIncompleteOrObjectType() && |
| 2426 | ToPointeeType->isVoidType()) { |
| 2427 | ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, |
| 2428 | ToPointeeType, |
| 2429 | ToType, Context, |
| 2430 | /*StripObjCLifetime=*/true); |
| 2431 | return true; |
| 2432 | } |
| 2433 | |
| 2434 | // MSVC allows implicit function to void* type conversion. |
| 2435 | if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() && |
| 2436 | ToPointeeType->isVoidType()) { |
| 2437 | ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, |
| 2438 | ToPointeeType, |
| 2439 | ToType, Context); |
| 2440 | return true; |
| 2441 | } |
| 2442 | |
| 2443 | // When we're overloading in C, we allow a special kind of pointer |
| 2444 | // conversion for compatible-but-not-identical pointee types. |
| 2445 | if (!getLangOpts().CPlusPlus && |
| 2446 | Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { |
| 2447 | ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, |
| 2448 | ToPointeeType, |
| 2449 | ToType, Context); |
| 2450 | return true; |
| 2451 | } |
| 2452 | |
| 2453 | // C++ [conv.ptr]p3: |
| 2454 | // |
| 2455 | // An rvalue of type "pointer to cv D," where D is a class type, |
| 2456 | // can be converted to an rvalue of type "pointer to cv B," where |
| 2457 | // B is a base class (clause 10) of D. If B is an inaccessible |
| 2458 | // (clause 11) or ambiguous (10.2) base class of D, a program that |
| 2459 | // necessitates this conversion is ill-formed. The result of the |
| 2460 | // conversion is a pointer to the base class sub-object of the |
| 2461 | // derived class object. The null pointer value is converted to |
| 2462 | // the null pointer value of the destination type. |
| 2463 | // |
| 2464 | // Note that we do not check for ambiguity or inaccessibility |
| 2465 | // here. That is handled by CheckPointerConversion. |
| 2466 | if (getLangOpts().CPlusPlus && FromPointeeType->isRecordType() && |
| 2467 | ToPointeeType->isRecordType() && |
| 2468 | !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && |
| 2469 | IsDerivedFrom(From->getBeginLoc(), FromPointeeType, ToPointeeType)) { |
| 2470 | ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, |
| 2471 | ToPointeeType, |
| 2472 | ToType, Context); |
| 2473 | return true; |
| 2474 | } |
| 2475 | |
| 2476 | if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() && |
| 2477 | Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) { |
| 2478 | ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, |
| 2479 | ToPointeeType, |
| 2480 | ToType, Context); |
| 2481 | return true; |
| 2482 | } |
| 2483 | |
| 2484 | return false; |
| 2485 | } |
| 2486 | |
| 2487 | /// Adopt the given qualifiers for the given type. |
| 2488 | static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){ |
| 2489 | Qualifiers TQs = T.getQualifiers(); |
| 2490 | |
| 2491 | // Check whether qualifiers already match. |
| 2492 | if (TQs == Qs) |
| 2493 | return T; |
| 2494 | |
| 2495 | if (Qs.compatiblyIncludes(TQs)) |
| 2496 | return Context.getQualifiedType(T, Qs); |
| 2497 | |
| 2498 | return Context.getQualifiedType(T.getUnqualifiedType(), Qs); |
| 2499 | } |
| 2500 | |
| 2501 | /// isObjCPointerConversion - Determines whether this is an |
| 2502 | /// Objective-C pointer conversion. Subroutine of IsPointerConversion, |
| 2503 | /// with the same arguments and return values. |
| 2504 | bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, |
| 2505 | QualType& ConvertedType, |
| 2506 | bool &IncompatibleObjC) { |
| 2507 | if (!getLangOpts().ObjC) |
| 2508 | return false; |
| 2509 | |
| 2510 | // The set of qualifiers on the type we're converting from. |
| 2511 | Qualifiers FromQualifiers = FromType.getQualifiers(); |
| 2512 | |
| 2513 | // First, we handle all conversions on ObjC object pointer types. |
| 2514 | const ObjCObjectPointerType* ToObjCPtr = |
| 2515 | ToType->getAs<ObjCObjectPointerType>(); |
| 2516 | const ObjCObjectPointerType *FromObjCPtr = |
| 2517 | FromType->getAs<ObjCObjectPointerType>(); |
| 2518 | |
| 2519 | if (ToObjCPtr && FromObjCPtr) { |
| 2520 | // If the pointee types are the same (ignoring qualifications), |
| 2521 | // then this is not a pointer conversion. |
| 2522 | if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), |
| 2523 | FromObjCPtr->getPointeeType())) |
| 2524 | return false; |
| 2525 | |
| 2526 | // Conversion between Objective-C pointers. |
| 2527 | if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { |
| 2528 | const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); |
| 2529 | const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); |
| 2530 | if (getLangOpts().CPlusPlus && LHS && RHS && |
| 2531 | !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( |
| 2532 | FromObjCPtr->getPointeeType())) |
| 2533 | return false; |
| 2534 | ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, |
| 2535 | ToObjCPtr->getPointeeType(), |
| 2536 | ToType, Context); |
| 2537 | ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); |
| 2538 | return true; |
| 2539 | } |
| 2540 | |
| 2541 | if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { |
| 2542 | // Okay: this is some kind of implicit downcast of Objective-C |
| 2543 | // interfaces, which is permitted. However, we're going to |
| 2544 | // complain about it. |
| 2545 | IncompatibleObjC = true; |
| 2546 | ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, |
| 2547 | ToObjCPtr->getPointeeType(), |
| 2548 | ToType, Context); |
| 2549 | ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); |
| 2550 | return true; |
| 2551 | } |
| 2552 | } |
| 2553 | // Beyond this point, both types need to be C pointers or block pointers. |
| 2554 | QualType ToPointeeType; |
| 2555 | if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) |
| 2556 | ToPointeeType = ToCPtr->getPointeeType(); |
| 2557 | else if (const BlockPointerType *ToBlockPtr = |
| 2558 | ToType->getAs<BlockPointerType>()) { |
| 2559 | // Objective C++: We're able to convert from a pointer to any object |
| 2560 | // to a block pointer type. |
| 2561 | if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { |
| 2562 | ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); |
| 2563 | return true; |
| 2564 | } |
| 2565 | ToPointeeType = ToBlockPtr->getPointeeType(); |
| 2566 | } |
| 2567 | else if (FromType->getAs<BlockPointerType>() && |
| 2568 | ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { |
| 2569 | // Objective C++: We're able to convert from a block pointer type to a |
| 2570 | // pointer to any object. |
| 2571 | ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); |
| 2572 | return true; |
| 2573 | } |
| 2574 | else |
| 2575 | return false; |
| 2576 | |
| 2577 | QualType FromPointeeType; |
| 2578 | if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) |
| 2579 | FromPointeeType = FromCPtr->getPointeeType(); |
| 2580 | else if (const BlockPointerType *FromBlockPtr = |
| 2581 | FromType->getAs<BlockPointerType>()) |
| 2582 | FromPointeeType = FromBlockPtr->getPointeeType(); |
| 2583 | else |
| 2584 | return false; |
| 2585 | |
| 2586 | // If we have pointers to pointers, recursively check whether this |
| 2587 | // is an Objective-C conversion. |
| 2588 | if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && |
| 2589 | isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, |
| 2590 | IncompatibleObjC)) { |
| 2591 | // We always complain about this conversion. |
| 2592 | IncompatibleObjC = true; |
| 2593 | ConvertedType = Context.getPointerType(ConvertedType); |
| 2594 | ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); |
| 2595 | return true; |
| 2596 | } |
| 2597 | // Allow conversion of pointee being objective-c pointer to another one; |
| 2598 | // as in I* to id. |
| 2599 | if (FromPointeeType->getAs<ObjCObjectPointerType>() && |
| 2600 | ToPointeeType->getAs<ObjCObjectPointerType>() && |
| 2601 | isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, |
| 2602 | IncompatibleObjC)) { |
| 2603 | |
| 2604 | ConvertedType = Context.getPointerType(ConvertedType); |
| 2605 | ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); |
| 2606 | return true; |
| 2607 | } |
| 2608 | |
| 2609 | // If we have pointers to functions or blocks, check whether the only |
| 2610 | // differences in the argument and result types are in Objective-C |
| 2611 | // pointer conversions. If so, we permit the conversion (but |
| 2612 | // complain about it). |
| 2613 | const FunctionProtoType *FromFunctionType |
| 2614 | = FromPointeeType->getAs<FunctionProtoType>(); |
| 2615 | const FunctionProtoType *ToFunctionType |
| 2616 | = ToPointeeType->getAs<FunctionProtoType>(); |
| 2617 | if (FromFunctionType && ToFunctionType) { |
| 2618 | // If the function types are exactly the same, this isn't an |
| 2619 | // Objective-C pointer conversion. |
| 2620 | if (Context.getCanonicalType(FromPointeeType) |
| 2621 | == Context.getCanonicalType(ToPointeeType)) |
| 2622 | return false; |
| 2623 | |
| 2624 | // Perform the quick checks that will tell us whether these |
| 2625 | // function types are obviously different. |
| 2626 | if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() || |
| 2627 | FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || |
| 2628 | FromFunctionType->getMethodQuals() != ToFunctionType->getMethodQuals()) |
| 2629 | return false; |
| 2630 | |
| 2631 | bool HasObjCConversion = false; |
| 2632 | if (Context.getCanonicalType(FromFunctionType->getReturnType()) == |
| 2633 | Context.getCanonicalType(ToFunctionType->getReturnType())) { |
| 2634 | // Okay, the types match exactly. Nothing to do. |
| 2635 | } else if (isObjCPointerConversion(FromFunctionType->getReturnType(), |
| 2636 | ToFunctionType->getReturnType(), |
| 2637 | ConvertedType, IncompatibleObjC)) { |
| 2638 | // Okay, we have an Objective-C pointer conversion. |
| 2639 | HasObjCConversion = true; |
| 2640 | } else { |
| 2641 | // Function types are too different. Abort. |
| 2642 | return false; |
| 2643 | } |
| 2644 | |
| 2645 | // Check argument types. |
| 2646 | for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams(); |
| 2647 | ArgIdx != NumArgs; ++ArgIdx) { |
| 2648 | QualType FromArgType = FromFunctionType->getParamType(ArgIdx); |
| 2649 | QualType ToArgType = ToFunctionType->getParamType(ArgIdx); |
| 2650 | if (Context.getCanonicalType(FromArgType) |
| 2651 | == Context.getCanonicalType(ToArgType)) { |
| 2652 | // Okay, the types match exactly. Nothing to do. |
| 2653 | } else if (isObjCPointerConversion(FromArgType, ToArgType, |
| 2654 | ConvertedType, IncompatibleObjC)) { |
| 2655 | // Okay, we have an Objective-C pointer conversion. |
| 2656 | HasObjCConversion = true; |
| 2657 | } else { |
| 2658 | // Argument types are too different. Abort. |
| 2659 | return false; |
| 2660 | } |
| 2661 | } |
| 2662 | |
| 2663 | if (HasObjCConversion) { |
| 2664 | // We had an Objective-C conversion. Allow this pointer |
| 2665 | // conversion, but complain about it. |
| 2666 | ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); |
| 2667 | IncompatibleObjC = true; |
| 2668 | return true; |
| 2669 | } |
| 2670 | } |
| 2671 | |
| 2672 | return false; |
| 2673 | } |
| 2674 | |
| 2675 | /// Determine whether this is an Objective-C writeback conversion, |
| 2676 | /// used for parameter passing when performing automatic reference counting. |
| 2677 | /// |
| 2678 | /// \param FromType The type we're converting form. |
| 2679 | /// |
| 2680 | /// \param ToType The type we're converting to. |
| 2681 | /// |
| 2682 | /// \param ConvertedType The type that will be produced after applying |
| 2683 | /// this conversion. |
| 2684 | bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType, |
| 2685 | QualType &ConvertedType) { |
| 2686 | if (!getLangOpts().ObjCAutoRefCount || |
| 2687 | Context.hasSameUnqualifiedType(FromType, ToType)) |
| 2688 | return false; |
| 2689 | |
| 2690 | // Parameter must be a pointer to __autoreleasing (with no other qualifiers). |
| 2691 | QualType ToPointee; |
| 2692 | if (const PointerType *ToPointer = ToType->getAs<PointerType>()) |
| 2693 | ToPointee = ToPointer->getPointeeType(); |
| 2694 | else |
| 2695 | return false; |
| 2696 | |
| 2697 | Qualifiers ToQuals = ToPointee.getQualifiers(); |
| 2698 | if (!ToPointee->isObjCLifetimeType() || |
| 2699 | ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing || |
| 2700 | !ToQuals.withoutObjCLifetime().empty()) |
| 2701 | return false; |
| 2702 | |
| 2703 | // Argument must be a pointer to __strong to __weak. |
| 2704 | QualType FromPointee; |
| 2705 | if (const PointerType *FromPointer = FromType->getAs<PointerType>()) |
| 2706 | FromPointee = FromPointer->getPointeeType(); |
| 2707 | else |
| 2708 | return false; |
| 2709 | |
| 2710 | Qualifiers FromQuals = FromPointee.getQualifiers(); |
| 2711 | if (!FromPointee->isObjCLifetimeType() || |
| 2712 | (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong && |
| 2713 | FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak)) |
| 2714 | return false; |
| 2715 | |
| 2716 | // Make sure that we have compatible qualifiers. |
| 2717 | FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing); |
| 2718 | if (!ToQuals.compatiblyIncludes(FromQuals)) |
| 2719 | return false; |
| 2720 | |
| 2721 | // Remove qualifiers from the pointee type we're converting from; they |
| 2722 | // aren't used in the compatibility check belong, and we'll be adding back |
| 2723 | // qualifiers (with __autoreleasing) if the compatibility check succeeds. |
| 2724 | FromPointee = FromPointee.getUnqualifiedType(); |
| 2725 | |
| 2726 | // The unqualified form of the pointee types must be compatible. |
| 2727 | ToPointee = ToPointee.getUnqualifiedType(); |
| 2728 | bool IncompatibleObjC; |
| 2729 | if (Context.typesAreCompatible(FromPointee, ToPointee)) |
| 2730 | FromPointee = ToPointee; |
| 2731 | else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee, |
| 2732 | IncompatibleObjC)) |
| 2733 | return false; |
| 2734 | |
| 2735 | /// Construct the type we're converting to, which is a pointer to |
| 2736 | /// __autoreleasing pointee. |
| 2737 | FromPointee = Context.getQualifiedType(FromPointee, FromQuals); |
| 2738 | ConvertedType = Context.getPointerType(FromPointee); |
| 2739 | return true; |
| 2740 | } |
| 2741 | |
| 2742 | bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, |
| 2743 | QualType& ConvertedType) { |
| 2744 | QualType ToPointeeType; |
| 2745 | if (const BlockPointerType *ToBlockPtr = |
| 2746 | ToType->getAs<BlockPointerType>()) |
| 2747 | ToPointeeType = ToBlockPtr->getPointeeType(); |
| 2748 | else |
| 2749 | return false; |
| 2750 | |
| 2751 | QualType FromPointeeType; |
| 2752 | if (const BlockPointerType *FromBlockPtr = |
| 2753 | FromType->getAs<BlockPointerType>()) |
| 2754 | FromPointeeType = FromBlockPtr->getPointeeType(); |
| 2755 | else |
| 2756 | return false; |
| 2757 | // We have pointer to blocks, check whether the only |
| 2758 | // differences in the argument and result types are in Objective-C |
| 2759 | // pointer conversions. If so, we permit the conversion. |
| 2760 | |
| 2761 | const FunctionProtoType *FromFunctionType |
| 2762 | = FromPointeeType->getAs<FunctionProtoType>(); |
| 2763 | const FunctionProtoType *ToFunctionType |
| 2764 | = ToPointeeType->getAs<FunctionProtoType>(); |
| 2765 | |
| 2766 | if (!FromFunctionType || !ToFunctionType) |
| 2767 | return false; |
| 2768 | |
| 2769 | if (Context.hasSameType(FromPointeeType, ToPointeeType)) |
| 2770 | return true; |
| 2771 | |
| 2772 | // Perform the quick checks that will tell us whether these |
| 2773 | // function types are obviously different. |
| 2774 | if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() || |
| 2775 | FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) |
| 2776 | return false; |
| 2777 | |
| 2778 | FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); |
| 2779 | FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); |
| 2780 | if (FromEInfo != ToEInfo) |
| 2781 | return false; |
| 2782 | |
| 2783 | bool IncompatibleObjC = false; |
| 2784 | if (Context.hasSameType(FromFunctionType->getReturnType(), |
| 2785 | ToFunctionType->getReturnType())) { |
| 2786 | // Okay, the types match exactly. Nothing to do. |
| 2787 | } else { |
| 2788 | QualType RHS = FromFunctionType->getReturnType(); |
| 2789 | QualType LHS = ToFunctionType->getReturnType(); |
| 2790 | if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) && |
| 2791 | !RHS.hasQualifiers() && LHS.hasQualifiers()) |
| 2792 | LHS = LHS.getUnqualifiedType(); |
| 2793 | |
| 2794 | if (Context.hasSameType(RHS,LHS)) { |
| 2795 | // OK exact match. |
| 2796 | } else if (isObjCPointerConversion(RHS, LHS, |
| 2797 | ConvertedType, IncompatibleObjC)) { |
| 2798 | if (IncompatibleObjC) |
| 2799 | return false; |
| 2800 | // Okay, we have an Objective-C pointer conversion. |
| 2801 | } |
| 2802 | else |
| 2803 | return false; |
| 2804 | } |
| 2805 | |
| 2806 | // Check argument types. |
| 2807 | for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams(); |
| 2808 | ArgIdx != NumArgs; ++ArgIdx) { |
| 2809 | IncompatibleObjC = false; |
| 2810 | QualType FromArgType = FromFunctionType->getParamType(ArgIdx); |
| 2811 | QualType ToArgType = ToFunctionType->getParamType(ArgIdx); |
| 2812 | if (Context.hasSameType(FromArgType, ToArgType)) { |
| 2813 | // Okay, the types match exactly. Nothing to do. |
| 2814 | } else if (isObjCPointerConversion(ToArgType, FromArgType, |
| 2815 | ConvertedType, IncompatibleObjC)) { |
| 2816 | if (IncompatibleObjC) |
| 2817 | return false; |
| 2818 | // Okay, we have an Objective-C pointer conversion. |
| 2819 | } else |
| 2820 | // Argument types are too different. Abort. |
| 2821 | return false; |
| 2822 | } |
| 2823 | |
| 2824 | SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos; |
| 2825 | bool CanUseToFPT, CanUseFromFPT; |
| 2826 | if (!Context.mergeExtParameterInfo(ToFunctionType, FromFunctionType, |
| 2827 | CanUseToFPT, CanUseFromFPT, |
| 2828 | NewParamInfos)) |
| 2829 | return false; |
| 2830 | |
| 2831 | ConvertedType = ToType; |
| 2832 | return true; |
| 2833 | } |
| 2834 | |
| 2835 | enum { |
| 2836 | ft_default, |
| 2837 | ft_different_class, |
| 2838 | ft_parameter_arity, |
| 2839 | ft_parameter_mismatch, |
| 2840 | ft_return_type, |
| 2841 | ft_qualifer_mismatch, |
| 2842 | ft_noexcept |
| 2843 | }; |
| 2844 | |
| 2845 | /// Attempts to get the FunctionProtoType from a Type. Handles |
| 2846 | /// MemberFunctionPointers properly. |
| 2847 | static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) { |
| 2848 | if (auto *FPT = FromType->getAs<FunctionProtoType>()) |
| 2849 | return FPT; |
| 2850 | |
| 2851 | if (auto *MPT = FromType->getAs<MemberPointerType>()) |
| 2852 | return MPT->getPointeeType()->getAs<FunctionProtoType>(); |
| 2853 | |
| 2854 | return nullptr; |
| 2855 | } |
| 2856 | |
| 2857 | /// HandleFunctionTypeMismatch - Gives diagnostic information for differeing |
| 2858 | /// function types. Catches different number of parameter, mismatch in |
| 2859 | /// parameter types, and different return types. |
| 2860 | void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag, |
| 2861 | QualType FromType, QualType ToType) { |
| 2862 | // If either type is not valid, include no extra info. |
| 2863 | if (FromType.isNull() || ToType.isNull()) { |
| 2864 | PDiag << ft_default; |
| 2865 | return; |
| 2866 | } |
| 2867 | |
| 2868 | // Get the function type from the pointers. |
| 2869 | if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) { |
| 2870 | const auto *FromMember = FromType->castAs<MemberPointerType>(), |
| 2871 | *ToMember = ToType->castAs<MemberPointerType>(); |
| 2872 | if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) { |
| 2873 | PDiag << ft_different_class << QualType(ToMember->getClass(), 0) |
| 2874 | << QualType(FromMember->getClass(), 0); |
| 2875 | return; |
| 2876 | } |
| 2877 | FromType = FromMember->getPointeeType(); |
| 2878 | ToType = ToMember->getPointeeType(); |
| 2879 | } |
| 2880 | |
| 2881 | if (FromType->isPointerType()) |
| 2882 | FromType = FromType->getPointeeType(); |
| 2883 | if (ToType->isPointerType()) |
| 2884 | ToType = ToType->getPointeeType(); |
| 2885 | |
| 2886 | // Remove references. |
| 2887 | FromType = FromType.getNonReferenceType(); |
| 2888 | ToType = ToType.getNonReferenceType(); |
| 2889 | |
| 2890 | // Don't print extra info for non-specialized template functions. |
| 2891 | if (FromType->isInstantiationDependentType() && |
| 2892 | !FromType->getAs<TemplateSpecializationType>()) { |
| 2893 | PDiag << ft_default; |
| 2894 | return; |
| 2895 | } |
| 2896 | |
| 2897 | // No extra info for same types. |
| 2898 | if (Context.hasSameType(FromType, ToType)) { |
| 2899 | PDiag << ft_default; |
| 2900 | return; |
| 2901 | } |
| 2902 | |
| 2903 | const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType), |
| 2904 | *ToFunction = tryGetFunctionProtoType(ToType); |
| 2905 | |
| 2906 | // Both types need to be function types. |
| 2907 | if (!FromFunction || !ToFunction) { |
| 2908 | PDiag << ft_default; |
| 2909 | return; |
| 2910 | } |
| 2911 | |
| 2912 | if (FromFunction->getNumParams() != ToFunction->getNumParams()) { |
| 2913 | PDiag << ft_parameter_arity << ToFunction->getNumParams() |
| 2914 | << FromFunction->getNumParams(); |
| 2915 | return; |
| 2916 | } |
| 2917 | |
| 2918 | // Handle different parameter types. |
| 2919 | unsigned ArgPos; |
| 2920 | if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) { |
| 2921 | PDiag << ft_parameter_mismatch << ArgPos + 1 |
| 2922 | << ToFunction->getParamType(ArgPos) |
| 2923 | << FromFunction->getParamType(ArgPos); |
| 2924 | return; |
| 2925 | } |
| 2926 | |
| 2927 | // Handle different return type. |
| 2928 | if (!Context.hasSameType(FromFunction->getReturnType(), |
| 2929 | ToFunction->getReturnType())) { |
| 2930 | PDiag << ft_return_type << ToFunction->getReturnType() |
| 2931 | << FromFunction->getReturnType(); |
| 2932 | return; |
| 2933 | } |
| 2934 | |
| 2935 | if (FromFunction->getMethodQuals() != ToFunction->getMethodQuals()) { |
| 2936 | PDiag << ft_qualifer_mismatch << ToFunction->getMethodQuals() |
| 2937 | << FromFunction->getMethodQuals(); |
| 2938 | return; |
| 2939 | } |
| 2940 | |
| 2941 | // Handle exception specification differences on canonical type (in C++17 |
| 2942 | // onwards). |
| 2943 | if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified()) |
| 2944 | ->isNothrow() != |
| 2945 | cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified()) |
| 2946 | ->isNothrow()) { |
| 2947 | PDiag << ft_noexcept; |
| 2948 | return; |
| 2949 | } |
| 2950 | |
| 2951 | // Unable to find a difference, so add no extra info. |
| 2952 | PDiag << ft_default; |
| 2953 | } |
| 2954 | |
| 2955 | /// FunctionParamTypesAreEqual - This routine checks two function proto types |
| 2956 | /// for equality of their argument types. Caller has already checked that |
| 2957 | /// they have same number of arguments. If the parameters are different, |
| 2958 | /// ArgPos will have the parameter index of the first different parameter. |
| 2959 | bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType, |
| 2960 | const FunctionProtoType *NewType, |
| 2961 | unsigned *ArgPos) { |
| 2962 | for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(), |
| 2963 | N = NewType->param_type_begin(), |
| 2964 | E = OldType->param_type_end(); |
| 2965 | O && (O != E); ++O, ++N) { |
| 2966 | // Ignore address spaces in pointee type. This is to disallow overloading |
| 2967 | // on __ptr32/__ptr64 address spaces. |
| 2968 | QualType Old = Context.removePtrSizeAddrSpace(O->getUnqualifiedType()); |
| 2969 | QualType New = Context.removePtrSizeAddrSpace(N->getUnqualifiedType()); |
| 2970 | |
| 2971 | if (!Context.hasSameType(Old, New)) { |
| 2972 | if (ArgPos) |
| 2973 | *ArgPos = O - OldType->param_type_begin(); |
| 2974 | return false; |
| 2975 | } |
| 2976 | } |
| 2977 | return true; |
| 2978 | } |
| 2979 | |
| 2980 | /// CheckPointerConversion - Check the pointer conversion from the |
| 2981 | /// expression From to the type ToType. This routine checks for |
| 2982 | /// ambiguous or inaccessible derived-to-base pointer |
| 2983 | /// conversions for which IsPointerConversion has already returned |
| 2984 | /// true. It returns true and produces a diagnostic if there was an |
| 2985 | /// error, or returns false otherwise. |
| 2986 | bool Sema::CheckPointerConversion(Expr *From, QualType ToType, |
| 2987 | CastKind &Kind, |
| 2988 | CXXCastPath& BasePath, |
| 2989 | bool IgnoreBaseAccess, |
| 2990 | bool Diagnose) { |
| 2991 | QualType FromType = From->getType(); |
| 2992 | bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; |
| 2993 | |
| 2994 | Kind = CK_BitCast; |
| 2995 | |
| 2996 | if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() && |
| 2997 | From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) == |
| 2998 | Expr::NPCK_ZeroExpression) { |
| 2999 | if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy)) |
| 3000 | DiagRuntimeBehavior(From->getExprLoc(), From, |
| 3001 | PDiag(diag::warn_impcast_bool_to_null_pointer) |
| 3002 | << ToType << From->getSourceRange()); |
| 3003 | else if (!isUnevaluatedContext()) |
| 3004 | Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer) |
| 3005 | << ToType << From->getSourceRange(); |
| 3006 | } |
| 3007 | if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { |
| 3008 | if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) { |
| 3009 | QualType FromPointeeType = FromPtrType->getPointeeType(), |
| 3010 | ToPointeeType = ToPtrType->getPointeeType(); |
| 3011 | |
| 3012 | if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && |
| 3013 | !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { |
| 3014 | // We must have a derived-to-base conversion. Check an |
| 3015 | // ambiguous or inaccessible conversion. |
| 3016 | unsigned InaccessibleID = 0; |
| 3017 | unsigned AmbiguousID = 0; |
| 3018 | if (Diagnose) { |
| 3019 | InaccessibleID = diag::err_upcast_to_inaccessible_base; |
| 3020 | AmbiguousID = diag::err_ambiguous_derived_to_base_conv; |
| 3021 | } |
| 3022 | if (CheckDerivedToBaseConversion( |
| 3023 | FromPointeeType, ToPointeeType, InaccessibleID, AmbiguousID, |
| 3024 | From->getExprLoc(), From->getSourceRange(), DeclarationName(), |
| 3025 | &BasePath, IgnoreBaseAccess)) |
| 3026 | return true; |
| 3027 | |
| 3028 | // The conversion was successful. |
| 3029 | Kind = CK_DerivedToBase; |
| 3030 | } |
| 3031 | |
| 3032 | if (Diagnose && !IsCStyleOrFunctionalCast && |
| 3033 | FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) { |
| 3034 | assert(getLangOpts().MSVCCompat &&((void)0) |
| 3035 | "this should only be possible with MSVCCompat!")((void)0); |
| 3036 | Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj) |
| 3037 | << From->getSourceRange(); |
| 3038 | } |
| 3039 | } |
| 3040 | } else if (const ObjCObjectPointerType *ToPtrType = |
| 3041 | ToType->getAs<ObjCObjectPointerType>()) { |
| 3042 | if (const ObjCObjectPointerType *FromPtrType = |
| 3043 | FromType->getAs<ObjCObjectPointerType>()) { |
| 3044 | // Objective-C++ conversions are always okay. |
| 3045 | // FIXME: We should have a different class of conversions for the |
| 3046 | // Objective-C++ implicit conversions. |
| 3047 | if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) |
| 3048 | return false; |
| 3049 | } else if (FromType->isBlockPointerType()) { |
| 3050 | Kind = CK_BlockPointerToObjCPointerCast; |
| 3051 | } else { |
| 3052 | Kind = CK_CPointerToObjCPointerCast; |
| 3053 | } |
| 3054 | } else if (ToType->isBlockPointerType()) { |
| 3055 | if (!FromType->isBlockPointerType()) |
| 3056 | Kind = CK_AnyPointerToBlockPointerCast; |
| 3057 | } |
| 3058 | |
| 3059 | // We shouldn't fall into this case unless it's valid for other |
| 3060 | // reasons. |
| 3061 | if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) |
| 3062 | Kind = CK_NullToPointer; |
| 3063 | |
| 3064 | return false; |
| 3065 | } |
| 3066 | |
| 3067 | /// IsMemberPointerConversion - Determines whether the conversion of the |
| 3068 | /// expression From, which has the (possibly adjusted) type FromType, can be |
| 3069 | /// converted to the type ToType via a member pointer conversion (C++ 4.11). |
| 3070 | /// If so, returns true and places the converted type (that might differ from |
| 3071 | /// ToType in its cv-qualifiers at some level) into ConvertedType. |
| 3072 | bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, |
| 3073 | QualType ToType, |
| 3074 | bool InOverloadResolution, |
| 3075 | QualType &ConvertedType) { |
| 3076 | const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); |
| 3077 | if (!ToTypePtr) |
| 3078 | return false; |
| 3079 | |
| 3080 | // A null pointer constant can be converted to a member pointer (C++ 4.11p1) |
| 3081 | if (From->isNullPointerConstant(Context, |
| 3082 | InOverloadResolution? Expr::NPC_ValueDependentIsNotNull |
| 3083 | : Expr::NPC_ValueDependentIsNull)) { |
| 3084 | ConvertedType = ToType; |
| 3085 | return true; |
| 3086 | } |
| 3087 | |
| 3088 | // Otherwise, both types have to be member pointers. |
| 3089 | const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); |
| 3090 | if (!FromTypePtr) |
| 3091 | return false; |
| 3092 | |
| 3093 | // A pointer to member of B can be converted to a pointer to member of D, |
| 3094 | // where D is derived from B (C++ 4.11p2). |
| 3095 | QualType FromClass(FromTypePtr->getClass(), 0); |
| 3096 | QualType ToClass(ToTypePtr->getClass(), 0); |
| 3097 | |
| 3098 | if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && |
| 3099 | IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass)) { |
| 3100 | ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), |
| 3101 | ToClass.getTypePtr()); |
| 3102 | return true; |
| 3103 | } |
| 3104 | |
| 3105 | return false; |
| 3106 | } |
| 3107 | |
| 3108 | /// CheckMemberPointerConversion - Check the member pointer conversion from the |
| 3109 | /// expression From to the type ToType. This routine checks for ambiguous or |
| 3110 | /// virtual or inaccessible base-to-derived member pointer conversions |
| 3111 | /// for which IsMemberPointerConversion has already returned true. It returns |
| 3112 | /// true and produces a diagnostic if there was an error, or returns false |
| 3113 | /// otherwise. |
| 3114 | bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, |
| 3115 | CastKind &Kind, |
| 3116 | CXXCastPath &BasePath, |
| 3117 | bool IgnoreBaseAccess) { |
| 3118 | QualType FromType = From->getType(); |
| 3119 | const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); |
| 3120 | if (!FromPtrType) { |
| 3121 | // This must be a null pointer to member pointer conversion |
| 3122 | assert(From->isNullPointerConstant(Context,((void)0) |
| 3123 | Expr::NPC_ValueDependentIsNull) &&((void)0) |
| 3124 | "Expr must be null pointer constant!")((void)0); |
| 3125 | Kind = CK_NullToMemberPointer; |
| 3126 | return false; |
| 3127 | } |
| 3128 | |
| 3129 | const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); |
| 3130 | assert(ToPtrType && "No member pointer cast has a target type "((void)0) |
| 3131 | "that is not a member pointer.")((void)0); |
| 3132 | |
| 3133 | QualType FromClass = QualType(FromPtrType->getClass(), 0); |
| 3134 | QualType ToClass = QualType(ToPtrType->getClass(), 0); |
| 3135 | |
| 3136 | // FIXME: What about dependent types? |
| 3137 | assert(FromClass->isRecordType() && "Pointer into non-class.")((void)0); |
| 3138 | assert(ToClass->isRecordType() && "Pointer into non-class.")((void)0); |
| 3139 | |
| 3140 | CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, |
| 3141 | /*DetectVirtual=*/true); |
| 3142 | bool DerivationOkay = |
| 3143 | IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass, Paths); |
| 3144 | assert(DerivationOkay &&((void)0) |
| 3145 | "Should not have been called if derivation isn't OK.")((void)0); |
| 3146 | (void)DerivationOkay; |
| 3147 | |
| 3148 | if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). |
| 3149 | getUnqualifiedType())) { |
| 3150 | std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); |
| 3151 | Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) |
| 3152 | << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); |
| 3153 | return true; |
| 3154 | } |
| 3155 | |
| 3156 | if (const RecordType *VBase = Paths.getDetectedVirtual()) { |
| 3157 | Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) |
| 3158 | << FromClass << ToClass << QualType(VBase, 0) |
| 3159 | << From->getSourceRange(); |
| 3160 | return true; |
| 3161 | } |
| 3162 | |
| 3163 | if (!IgnoreBaseAccess) |
| 3164 | CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, |
| 3165 | Paths.front(), |
| 3166 | diag::err_downcast_from_inaccessible_base); |
| 3167 | |
| 3168 | // Must be a base to derived member conversion. |
| 3169 | BuildBasePathArray(Paths, BasePath); |
| 3170 | Kind = CK_BaseToDerivedMemberPointer; |
| 3171 | return false; |
| 3172 | } |
| 3173 | |
| 3174 | /// Determine whether the lifetime conversion between the two given |
| 3175 | /// qualifiers sets is nontrivial. |
| 3176 | static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals, |
| 3177 | Qualifiers ToQuals) { |
| 3178 | // Converting anything to const __unsafe_unretained is trivial. |
| 3179 | if (ToQuals.hasConst() && |
| 3180 | ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone) |
| 3181 | return false; |
| 3182 | |
| 3183 | return true; |
| 3184 | } |
| 3185 | |
| 3186 | /// Perform a single iteration of the loop for checking if a qualification |
| 3187 | /// conversion is valid. |
| 3188 | /// |
| 3189 | /// Specifically, check whether any change between the qualifiers of \p |
| 3190 | /// FromType and \p ToType is permissible, given knowledge about whether every |
| 3191 | /// outer layer is const-qualified. |
| 3192 | static bool isQualificationConversionStep(QualType FromType, QualType ToType, |
| 3193 | bool CStyle, bool IsTopLevel, |
| 3194 | bool &PreviousToQualsIncludeConst, |
| 3195 | bool &ObjCLifetimeConversion) { |
| 3196 | Qualifiers FromQuals = FromType.getQualifiers(); |
| 3197 | Qualifiers ToQuals = ToType.getQualifiers(); |
| 3198 | |
| 3199 | // Ignore __unaligned qualifier if this type is void. |
| 3200 | if (ToType.getUnqualifiedType()->isVoidType()) |
| 3201 | FromQuals.removeUnaligned(); |
| 3202 | |
| 3203 | // Objective-C ARC: |
| 3204 | // Check Objective-C lifetime conversions. |
| 3205 | if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime()) { |
| 3206 | if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) { |
| 3207 | if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals)) |
| 3208 | ObjCLifetimeConversion = true; |
| 3209 | FromQuals.removeObjCLifetime(); |
| 3210 | ToQuals.removeObjCLifetime(); |
| 3211 | } else { |
| 3212 | // Qualification conversions cannot cast between different |
| 3213 | // Objective-C lifetime qualifiers. |
| 3214 | return false; |
| 3215 | } |
| 3216 | } |
| 3217 | |
| 3218 | // Allow addition/removal of GC attributes but not changing GC attributes. |
| 3219 | if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() && |
| 3220 | (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) { |
| 3221 | FromQuals.removeObjCGCAttr(); |
| 3222 | ToQuals.removeObjCGCAttr(); |
| 3223 | } |
| 3224 | |
| 3225 | // -- for every j > 0, if const is in cv 1,j then const is in cv |
| 3226 | // 2,j, and similarly for volatile. |
| 3227 | if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals)) |
| 3228 | return false; |
| 3229 | |
| 3230 | // If address spaces mismatch: |
| 3231 | // - in top level it is only valid to convert to addr space that is a |
| 3232 | // superset in all cases apart from C-style casts where we allow |
| 3233 | // conversions between overlapping address spaces. |
| 3234 | // - in non-top levels it is not a valid conversion. |
| 3235 | if (ToQuals.getAddressSpace() != FromQuals.getAddressSpace() && |
| 3236 | (!IsTopLevel || |
| 3237 | !(ToQuals.isAddressSpaceSupersetOf(FromQuals) || |
| 3238 | (CStyle && FromQuals.isAddressSpaceSupersetOf(ToQuals))))) |
| 3239 | return false; |
| 3240 | |
| 3241 | // -- if the cv 1,j and cv 2,j are different, then const is in |
| 3242 | // every cv for 0 < k < j. |
| 3243 | if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() && |
| 3244 | !PreviousToQualsIncludeConst) |
| 3245 | return false; |
| 3246 | |
| 3247 | // Keep track of whether all prior cv-qualifiers in the "to" type |
| 3248 | // include const. |
| 3249 | PreviousToQualsIncludeConst = |
| 3250 | PreviousToQualsIncludeConst && ToQuals.hasConst(); |
| 3251 | return true; |
| 3252 | } |
| 3253 | |
| 3254 | /// IsQualificationConversion - Determines whether the conversion from |
| 3255 | /// an rvalue of type FromType to ToType is a qualification conversion |
| 3256 | /// (C++ 4.4). |
| 3257 | /// |
| 3258 | /// \param ObjCLifetimeConversion Output parameter that will be set to indicate |
| 3259 | /// when the qualification conversion involves a change in the Objective-C |
| 3260 | /// object lifetime. |
| 3261 | bool |
| 3262 | Sema::IsQualificationConversion(QualType FromType, QualType ToType, |
| 3263 | bool CStyle, bool &ObjCLifetimeConversion) { |
| 3264 | FromType = Context.getCanonicalType(FromType); |
| 3265 | ToType = Context.getCanonicalType(ToType); |
| 3266 | ObjCLifetimeConversion = false; |
| 3267 | |
| 3268 | // If FromType and ToType are the same type, this is not a |
| 3269 | // qualification conversion. |
| 3270 | if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) |
| 3271 | return false; |
| 3272 | |
| 3273 | // (C++ 4.4p4): |
| 3274 | // A conversion can add cv-qualifiers at levels other than the first |
| 3275 | // in multi-level pointers, subject to the following rules: [...] |
| 3276 | bool PreviousToQualsIncludeConst = true; |
| 3277 | bool UnwrappedAnyPointer = false; |
| 3278 | while (Context.UnwrapSimilarTypes(FromType, ToType)) { |
| 3279 | if (!isQualificationConversionStep( |
| 3280 | FromType, ToType, CStyle, !UnwrappedAnyPointer, |
| 3281 | PreviousToQualsIncludeConst, ObjCLifetimeConversion)) |
| 3282 | return false; |
| 3283 | UnwrappedAnyPointer = true; |
| 3284 | } |
| 3285 | |
| 3286 | // We are left with FromType and ToType being the pointee types |
| 3287 | // after unwrapping the original FromType and ToType the same number |
| 3288 | // of times. If we unwrapped any pointers, and if FromType and |
| 3289 | // ToType have the same unqualified type (since we checked |
| 3290 | // qualifiers above), then this is a qualification conversion. |
| 3291 | return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); |
| 3292 | } |
| 3293 | |
| 3294 | /// - Determine whether this is a conversion from a scalar type to an |
| 3295 | /// atomic type. |
| 3296 | /// |
| 3297 | /// If successful, updates \c SCS's second and third steps in the conversion |
| 3298 | /// sequence to finish the conversion. |
| 3299 | static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, |
| 3300 | bool InOverloadResolution, |
| 3301 | StandardConversionSequence &SCS, |
| 3302 | bool CStyle) { |
| 3303 | const AtomicType *ToAtomic = ToType->getAs<AtomicType>(); |
| 3304 | if (!ToAtomic) |
| 3305 | return false; |
| 3306 | |
| 3307 | StandardConversionSequence InnerSCS; |
| 3308 | if (!IsStandardConversion(S, From, ToAtomic->getValueType(), |
| 3309 | InOverloadResolution, InnerSCS, |
| 3310 | CStyle, /*AllowObjCWritebackConversion=*/false)) |
| 3311 | return false; |
| 3312 | |
| 3313 | SCS.Second = InnerSCS.Second; |
| 3314 | SCS.setToType(1, InnerSCS.getToType(1)); |
| 3315 | SCS.Third = InnerSCS.Third; |
| 3316 | SCS.QualificationIncludesObjCLifetime |
| 3317 | = InnerSCS.QualificationIncludesObjCLifetime; |
| 3318 | SCS.setToType(2, InnerSCS.getToType(2)); |
| 3319 | return true; |
| 3320 | } |
| 3321 | |
| 3322 | static bool isFirstArgumentCompatibleWithType(ASTContext &Context, |
| 3323 | CXXConstructorDecl *Constructor, |
| 3324 | QualType Type) { |
| 3325 | const auto *CtorType = Constructor->getType()->castAs<FunctionProtoType>(); |
| 3326 | if (CtorType->getNumParams() > 0) { |
| 3327 | QualType FirstArg = CtorType->getParamType(0); |
| 3328 | if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType())) |
| 3329 | return true; |
| 3330 | } |
| 3331 | return false; |
| 3332 | } |
| 3333 | |
| 3334 | static OverloadingResult |
| 3335 | IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType, |
| 3336 | CXXRecordDecl *To, |
| 3337 | UserDefinedConversionSequence &User, |
| 3338 | OverloadCandidateSet &CandidateSet, |
| 3339 | bool AllowExplicit) { |
| 3340 | CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion); |
| 3341 | for (auto *D : S.LookupConstructors(To)) { |
| 3342 | auto Info = getConstructorInfo(D); |
| 3343 | if (!Info) |
| 3344 | continue; |
| 3345 | |
| 3346 | bool Usable = !Info.Constructor->isInvalidDecl() && |
| 3347 | S.isInitListConstructor(Info.Constructor); |
| 3348 | if (Usable) { |
| 3349 | bool SuppressUserConversions = false; |
| 3350 | if (Info.ConstructorTmpl) |
| 3351 | S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl, |
| 3352 | /*ExplicitArgs*/ nullptr, From, |
| 3353 | CandidateSet, SuppressUserConversions, |
| 3354 | /*PartialOverloading*/ false, |
| 3355 | AllowExplicit); |
| 3356 | else |
| 3357 | S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From, |
| 3358 | CandidateSet, SuppressUserConversions, |
| 3359 | /*PartialOverloading*/ false, AllowExplicit); |
| 3360 | } |
| 3361 | } |
| 3362 | |
| 3363 | bool HadMultipleCandidates = (CandidateSet.size() > 1); |
| 3364 | |
| 3365 | OverloadCandidateSet::iterator Best; |
| 3366 | switch (auto Result = |
| 3367 | CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) { |
| 3368 | case OR_Deleted: |
| 3369 | case OR_Success: { |
| 3370 | // Record the standard conversion we used and the conversion function. |
| 3371 | CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function); |
| 3372 | QualType ThisType = Constructor->getThisType(); |
| 3373 | // Initializer lists don't have conversions as such. |
| 3374 | User.Before.setAsIdentityConversion(); |
| 3375 | User.HadMultipleCandidates = HadMultipleCandidates; |
| 3376 | User.ConversionFunction = Constructor; |
| 3377 | User.FoundConversionFunction = Best->FoundDecl; |
| 3378 | User.After.setAsIdentityConversion(); |
| 3379 | User.After.setFromType(ThisType->castAs<PointerType>()->getPointeeType()); |
| 3380 | User.After.setAllToTypes(ToType); |
| 3381 | return Result; |
| 3382 | } |
| 3383 | |
| 3384 | case OR_No_Viable_Function: |
| 3385 | return OR_No_Viable_Function; |
| 3386 | case OR_Ambiguous: |
| 3387 | return OR_Ambiguous; |
| 3388 | } |
| 3389 | |
| 3390 | llvm_unreachable("Invalid OverloadResult!")__builtin_unreachable(); |
| 3391 | } |
| 3392 | |
| 3393 | /// Determines whether there is a user-defined conversion sequence |
| 3394 | /// (C++ [over.ics.user]) that converts expression From to the type |
| 3395 | /// ToType. If such a conversion exists, User will contain the |
| 3396 | /// user-defined conversion sequence that performs such a conversion |
| 3397 | /// and this routine will return true. Otherwise, this routine returns |
| 3398 | /// false and User is unspecified. |
| 3399 | /// |
| 3400 | /// \param AllowExplicit true if the conversion should consider C++0x |
| 3401 | /// "explicit" conversion functions as well as non-explicit conversion |
| 3402 | /// functions (C++0x [class.conv.fct]p2). |
| 3403 | /// |
| 3404 | /// \param AllowObjCConversionOnExplicit true if the conversion should |
| 3405 | /// allow an extra Objective-C pointer conversion on uses of explicit |
| 3406 | /// constructors. Requires \c AllowExplicit to also be set. |
| 3407 | static OverloadingResult |
| 3408 | IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, |
| 3409 | UserDefinedConversionSequence &User, |
| 3410 | OverloadCandidateSet &CandidateSet, |
| 3411 | AllowedExplicit AllowExplicit, |
| 3412 | bool AllowObjCConversionOnExplicit) { |
| 3413 | assert(AllowExplicit != AllowedExplicit::None ||((void)0) |
| 3414 | !AllowObjCConversionOnExplicit)((void)0); |
| 3415 | CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion); |
| 3416 | |
| 3417 | // Whether we will only visit constructors. |
| 3418 | bool ConstructorsOnly = false; |
| 3419 | |
| 3420 | // If the type we are conversion to is a class type, enumerate its |
| 3421 | // constructors. |
| 3422 | if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { |
| 3423 | // C++ [over.match.ctor]p1: |
| 3424 | // When objects of class type are direct-initialized (8.5), or |
| 3425 | // copy-initialized from an expression of the same or a |
| 3426 | // derived class type (8.5), overload resolution selects the |
| 3427 | // constructor. [...] For copy-initialization, the candidate |
| 3428 | // functions are all the converting constructors (12.3.1) of |
| 3429 | // that class. The argument list is the expression-list within |
| 3430 | // the parentheses of the initializer. |
| 3431 | if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || |
| 3432 | (From->getType()->getAs<RecordType>() && |
| 3433 | S.IsDerivedFrom(From->getBeginLoc(), From->getType(), ToType))) |
| 3434 | ConstructorsOnly = true; |
| 3435 | |
| 3436 | if (!S.isCompleteType(From->getExprLoc(), ToType)) { |
| 3437 | // We're not going to find any constructors. |
| 3438 | } else if (CXXRecordDecl *ToRecordDecl |
| 3439 | = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { |
| 3440 | |
| 3441 | Expr **Args = &From; |
| 3442 | unsigned NumArgs = 1; |
| 3443 | bool ListInitializing = false; |
| 3444 | if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) { |
| 3445 | // But first, see if there is an init-list-constructor that will work. |
| 3446 | OverloadingResult Result = IsInitializerListConstructorConversion( |
| 3447 | S, From, ToType, ToRecordDecl, User, CandidateSet, |
| 3448 | AllowExplicit == AllowedExplicit::All); |
| 3449 | if (Result != OR_No_Viable_Function) |
| 3450 | return Result; |
| 3451 | // Never mind. |
| 3452 | CandidateSet.clear( |
| 3453 | OverloadCandidateSet::CSK_InitByUserDefinedConversion); |
| 3454 | |
| 3455 | // If we're list-initializing, we pass the individual elements as |
| 3456 | // arguments, not the entire list. |
| 3457 | Args = InitList->getInits(); |
| 3458 | NumArgs = InitList->getNumInits(); |
| 3459 | ListInitializing = true; |
| 3460 | } |
| 3461 | |
| 3462 | for (auto *D : S.LookupConstructors(ToRecordDecl)) { |
| 3463 | auto Info = getConstructorInfo(D); |
| 3464 | if (!Info) |
| 3465 | continue; |
| 3466 | |
| 3467 | bool Usable = !Info.Constructor->isInvalidDecl(); |
| 3468 | if (!ListInitializing) |
| 3469 | Usable = Usable && Info.Constructor->isConvertingConstructor( |
| 3470 | /*AllowExplicit*/ true); |
| 3471 | if (Usable) { |
| 3472 | bool SuppressUserConversions = !ConstructorsOnly; |
| 3473 | // C++20 [over.best.ics.general]/4.5: |
| 3474 | // if the target is the first parameter of a constructor [of class |
| 3475 | // X] and the constructor [...] is a candidate by [...] the second |
| 3476 | // phase of [over.match.list] when the initializer list has exactly |
| 3477 | // one element that is itself an initializer list, [...] and the |
| 3478 | // conversion is to X or reference to cv X, user-defined conversion |
| 3479 | // sequences are not cnosidered. |
| 3480 | if (SuppressUserConversions && ListInitializing) { |
| 3481 | SuppressUserConversions = |
| 3482 | NumArgs == 1 && isa<InitListExpr>(Args[0]) && |
| 3483 | isFirstArgumentCompatibleWithType(S.Context, Info.Constructor, |
| 3484 | ToType); |
| 3485 | } |
| 3486 | if (Info.ConstructorTmpl) |
| 3487 | S.AddTemplateOverloadCandidate( |
| 3488 | Info.ConstructorTmpl, Info.FoundDecl, |
| 3489 | /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs), |
| 3490 | CandidateSet, SuppressUserConversions, |
| 3491 | /*PartialOverloading*/ false, |
| 3492 | AllowExplicit == AllowedExplicit::All); |
| 3493 | else |
| 3494 | // Allow one user-defined conversion when user specifies a |
| 3495 | // From->ToType conversion via an static cast (c-style, etc). |
| 3496 | S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, |
| 3497 | llvm::makeArrayRef(Args, NumArgs), |
| 3498 | CandidateSet, SuppressUserConversions, |
| 3499 | /*PartialOverloading*/ false, |
| 3500 | AllowExplicit == AllowedExplicit::All); |
| 3501 | } |
| 3502 | } |
| 3503 | } |
| 3504 | } |
| 3505 | |
| 3506 | // Enumerate conversion functions, if we're allowed to. |
| 3507 | if (ConstructorsOnly || isa<InitListExpr>(From)) { |
| 3508 | } else if (!S.isCompleteType(From->getBeginLoc(), From->getType())) { |
| 3509 | // No conversion functions from incomplete types. |
| 3510 | } else if (const RecordType *FromRecordType = |
| 3511 | From->getType()->getAs<RecordType>()) { |
| 3512 | if (CXXRecordDecl *FromRecordDecl |
| 3513 | = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { |
| 3514 | // Add all of the conversion functions as candidates. |
| 3515 | const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions(); |
| 3516 | for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) { |
| 3517 | DeclAccessPair FoundDecl = I.getPair(); |
| 3518 | NamedDecl *D = FoundDecl.getDecl(); |
| 3519 | CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); |
| 3520 | if (isa<UsingShadowDecl>(D)) |
| 3521 | D = cast<UsingShadowDecl>(D)->getTargetDecl(); |
| 3522 | |
| 3523 | CXXConversionDecl *Conv; |
| 3524 | FunctionTemplateDecl *ConvTemplate; |
| 3525 | if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) |
| 3526 | Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); |
| 3527 | else |
| 3528 | Conv = cast<CXXConversionDecl>(D); |
| 3529 | |
| 3530 | if (ConvTemplate) |
| 3531 | S.AddTemplateConversionCandidate( |
| 3532 | ConvTemplate, FoundDecl, ActingContext, From, ToType, |
| 3533 | CandidateSet, AllowObjCConversionOnExplicit, |
| 3534 | AllowExplicit != AllowedExplicit::None); |
| 3535 | else |
| 3536 | S.AddConversionCandidate(Conv, FoundDecl, ActingContext, From, ToType, |
| 3537 | CandidateSet, AllowObjCConversionOnExplicit, |
| 3538 | AllowExplicit != AllowedExplicit::None); |
| 3539 | } |
| 3540 | } |
| 3541 | } |
| 3542 | |
| 3543 | bool HadMultipleCandidates = (CandidateSet.size() > 1); |
| 3544 | |
| 3545 | OverloadCandidateSet::iterator Best; |
| 3546 | switch (auto Result = |
| 3547 | CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) { |
| 3548 | case OR_Success: |
| 3549 | case OR_Deleted: |
| 3550 | // Record the standard conversion we used and the conversion function. |
| 3551 | if (CXXConstructorDecl *Constructor |
| 3552 | = dyn_cast<CXXConstructorDecl>(Best->Function)) { |
| 3553 | // C++ [over.ics.user]p1: |
| 3554 | // If the user-defined conversion is specified by a |
| 3555 | // constructor (12.3.1), the initial standard conversion |
| 3556 | // sequence converts the source type to the type required by |
| 3557 | // the argument of the constructor. |
| 3558 | // |
| 3559 | QualType ThisType = Constructor->getThisType(); |
| 3560 | if (isa<InitListExpr>(From)) { |
| 3561 | // Initializer lists don't have conversions as such. |
| 3562 | User.Before.setAsIdentityConversion(); |
| 3563 | } else { |
| 3564 | if (Best->Conversions[0].isEllipsis()) |
| 3565 | User.EllipsisConversion = true; |
| 3566 | else { |
| 3567 | User.Before = Best->Conversions[0].Standard; |
| 3568 | User.EllipsisConversion = false; |
| 3569 | } |
| 3570 | } |
| 3571 | User.HadMultipleCandidates = HadMultipleCandidates; |
| 3572 | User.ConversionFunction = Constructor; |
| 3573 | User.FoundConversionFunction = Best->FoundDecl; |
| 3574 | User.After.setAsIdentityConversion(); |
| 3575 | User.After.setFromType(ThisType->castAs<PointerType>()->getPointeeType()); |
| 3576 | User.After.setAllToTypes(ToType); |
| 3577 | return Result; |
| 3578 | } |
| 3579 | if (CXXConversionDecl *Conversion |
| 3580 | = dyn_cast<CXXConversionDecl>(Best->Function)) { |
| 3581 | // C++ [over.ics.user]p1: |
| 3582 | // |
| 3583 | // [...] If the user-defined conversion is specified by a |
| 3584 | // conversion function (12.3.2), the initial standard |
| 3585 | // conversion sequence converts the source type to the |
| 3586 | // implicit object parameter of the conversion function. |
| 3587 | User.Before = Best->Conversions[0].Standard; |
| 3588 | User.HadMultipleCandidates = HadMultipleCandidates; |
| 3589 | User.ConversionFunction = Conversion; |
| 3590 | User.FoundConversionFunction = Best->FoundDecl; |
| 3591 | User.EllipsisConversion = false; |
| 3592 | |
| 3593 | // C++ [over.ics.user]p2: |
| 3594 | // The second standard conversion sequence converts the |
| 3595 | // result of the user-defined conversion to the target type |
| 3596 | // for the sequence. Since an implicit conversion sequence |
| 3597 | // is an initialization, the special rules for |
| 3598 | // initialization by user-defined conversion apply when |
| 3599 | // selecting the best user-defined conversion for a |
| 3600 | // user-defined conversion sequence (see 13.3.3 and |
| 3601 | // 13.3.3.1). |
| 3602 | User.After = Best->FinalConversion; |
| 3603 | return Result; |
| 3604 | } |
| 3605 | llvm_unreachable("Not a constructor or conversion function?")__builtin_unreachable(); |
| 3606 | |
| 3607 | case OR_No_Viable_Function: |
| 3608 | return OR_No_Viable_Function; |
| 3609 | |
| 3610 | case OR_Ambiguous: |
| 3611 | return OR_Ambiguous; |
| 3612 | } |
| 3613 | |
| 3614 | llvm_unreachable("Invalid OverloadResult!")__builtin_unreachable(); |
| 3615 | } |
| 3616 | |
| 3617 | bool |
| 3618 | Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { |
| 3619 | ImplicitConversionSequence ICS; |
| 3620 | OverloadCandidateSet CandidateSet(From->getExprLoc(), |
| 3621 | OverloadCandidateSet::CSK_Normal); |
| 3622 | OverloadingResult OvResult = |
| 3623 | IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, |
| 3624 | CandidateSet, AllowedExplicit::None, false); |
| 3625 | |
| 3626 | if (!(OvResult == OR_Ambiguous || |
| 3627 | (OvResult == OR_No_Viable_Function && !CandidateSet.empty()))) |
| 3628 | return false; |
| 3629 | |
| 3630 | auto Cands = CandidateSet.CompleteCandidates( |
| 3631 | *this, |
| 3632 | OvResult == OR_Ambiguous ? OCD_AmbiguousCandidates : OCD_AllCandidates, |
| 3633 | From); |
| 3634 | if (OvResult == OR_Ambiguous) |
| 3635 | Diag(From->getBeginLoc(), diag::err_typecheck_ambiguous_condition) |
| 3636 | << From->getType() << ToType << From->getSourceRange(); |
| 3637 | else { // OR_No_Viable_Function && !CandidateSet.empty() |
| 3638 | if (!RequireCompleteType(From->getBeginLoc(), ToType, |
| 3639 | diag::err_typecheck_nonviable_condition_incomplete, |
| 3640 | From->getType(), From->getSourceRange())) |
| 3641 | Diag(From->getBeginLoc(), diag::err_typecheck_nonviable_condition) |
| 3642 | << false << From->getType() << From->getSourceRange() << ToType; |
| 3643 | } |
| 3644 | |
| 3645 | CandidateSet.NoteCandidates( |
| 3646 | *this, From, Cands); |
| 3647 | return true; |
| 3648 | } |
| 3649 | |
| 3650 | // Helper for compareConversionFunctions that gets the FunctionType that the |
| 3651 | // conversion-operator return value 'points' to, or nullptr. |
| 3652 | static const FunctionType * |
| 3653 | getConversionOpReturnTyAsFunction(CXXConversionDecl *Conv) { |
| 3654 | const FunctionType *ConvFuncTy = Conv->getType()->castAs<FunctionType>(); |
| 3655 | const PointerType *RetPtrTy = |
| 3656 | ConvFuncTy->getReturnType()->getAs<PointerType>(); |
| 3657 | |
| 3658 | if (!RetPtrTy) |
| 3659 | return nullptr; |
| 3660 | |
| 3661 | return RetPtrTy->getPointeeType()->getAs<FunctionType>(); |
| 3662 | } |
| 3663 | |
| 3664 | /// Compare the user-defined conversion functions or constructors |
| 3665 | /// of two user-defined conversion sequences to determine whether any ordering |
| 3666 | /// is possible. |
| 3667 | static ImplicitConversionSequence::CompareKind |
| 3668 | compareConversionFunctions(Sema &S, FunctionDecl *Function1, |
| 3669 | FunctionDecl *Function2) { |
| 3670 | CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1); |
| 3671 | CXXConversionDecl *Conv2 = dyn_cast_or_null<CXXConversionDecl>(Function2); |
| 3672 | if (!Conv1 || !Conv2) |
| 3673 | return ImplicitConversionSequence::Indistinguishable; |
| 3674 | |
| 3675 | if (!Conv1->getParent()->isLambda() || !Conv2->getParent()->isLambda()) |
| 3676 | return ImplicitConversionSequence::Indistinguishable; |
| 3677 | |
| 3678 | // Objective-C++: |
| 3679 | // If both conversion functions are implicitly-declared conversions from |
| 3680 | // a lambda closure type to a function pointer and a block pointer, |
| 3681 | // respectively, always prefer the conversion to a function pointer, |
| 3682 | // because the function pointer is more lightweight and is more likely |
| 3683 | // to keep code working. |
| 3684 | if (S.getLangOpts().ObjC && S.getLangOpts().CPlusPlus11) { |
| 3685 | bool Block1 = Conv1->getConversionType()->isBlockPointerType(); |
| 3686 | bool Block2 = Conv2->getConversionType()->isBlockPointerType(); |
| 3687 | if (Block1 != Block2) |
| 3688 | return Block1 ? ImplicitConversionSequence::Worse |
| 3689 | : ImplicitConversionSequence::Better; |
| 3690 | } |
| 3691 | |
| 3692 | // In order to support multiple calling conventions for the lambda conversion |
| 3693 | // operator (such as when the free and member function calling convention is |
| 3694 | // different), prefer the 'free' mechanism, followed by the calling-convention |
| 3695 | // of operator(). The latter is in place to support the MSVC-like solution of |
| 3696 | // defining ALL of the possible conversions in regards to calling-convention. |
| 3697 | const FunctionType *Conv1FuncRet = getConversionOpReturnTyAsFunction(Conv1); |
| 3698 | const FunctionType *Conv2FuncRet = getConversionOpReturnTyAsFunction(Conv2); |
| 3699 | |
| 3700 | if (Conv1FuncRet && Conv2FuncRet && |
| 3701 | Conv1FuncRet->getCallConv() != Conv2FuncRet->getCallConv()) { |
| 3702 | CallingConv Conv1CC = Conv1FuncRet->getCallConv(); |
| 3703 | CallingConv Conv2CC = Conv2FuncRet->getCallConv(); |
| 3704 | |
| 3705 | CXXMethodDecl *CallOp = Conv2->getParent()->getLambdaCallOperator(); |
| 3706 | const FunctionProtoType *CallOpProto = |
| 3707 | CallOp->getType()->getAs<FunctionProtoType>(); |
| 3708 | |
| 3709 | CallingConv CallOpCC = |
| 3710 | CallOp->getType()->castAs<FunctionType>()->getCallConv(); |
| 3711 | CallingConv DefaultFree = S.Context.getDefaultCallingConvention( |
| 3712 | CallOpProto->isVariadic(), /*IsCXXMethod=*/false); |
| 3713 | CallingConv DefaultMember = S.Context.getDefaultCallingConvention( |
| 3714 | CallOpProto->isVariadic(), /*IsCXXMethod=*/true); |
| 3715 | |
| 3716 | CallingConv PrefOrder[] = {DefaultFree, DefaultMember, CallOpCC}; |
| 3717 | for (CallingConv CC : PrefOrder) { |
| 3718 | if (Conv1CC == CC) |
| 3719 | return ImplicitConversionSequence::Better; |
| 3720 | if (Conv2CC == CC) |
| 3721 | return ImplicitConversionSequence::Worse; |
| 3722 | } |
| 3723 | } |
| 3724 | |
| 3725 | return ImplicitConversionSequence::Indistinguishable; |
| 3726 | } |
| 3727 | |
| 3728 | static bool hasDeprecatedStringLiteralToCharPtrConversion( |
| 3729 | const ImplicitConversionSequence &ICS) { |
| 3730 | return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) || |
| 3731 | (ICS.isUserDefined() && |
| 3732 | ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr); |
| 3733 | } |
| 3734 | |
| 3735 | /// CompareImplicitConversionSequences - Compare two implicit |
| 3736 | /// conversion sequences to determine whether one is better than the |
| 3737 | /// other or if they are indistinguishable (C++ 13.3.3.2). |
| 3738 | static ImplicitConversionSequence::CompareKind |
| 3739 | CompareImplicitConversionSequences(Sema &S, SourceLocation Loc, |
| 3740 | const ImplicitConversionSequence& ICS1, |
| 3741 | const ImplicitConversionSequence& ICS2) |
| 3742 | { |
| 3743 | // (C++ 13.3.3.2p2): When comparing the basic forms of implicit |
| 3744 | // conversion sequences (as defined in 13.3.3.1) |
| 3745 | // -- a standard conversion sequence (13.3.3.1.1) is a better |
| 3746 | // conversion sequence than a user-defined conversion sequence or |
| 3747 | // an ellipsis conversion sequence, and |
| 3748 | // -- a user-defined conversion sequence (13.3.3.1.2) is a better |
| 3749 | // conversion sequence than an ellipsis conversion sequence |
| 3750 | // (13.3.3.1.3). |
| 3751 | // |
| 3752 | // C++0x [over.best.ics]p10: |
| 3753 | // For the purpose of ranking implicit conversion sequences as |
| 3754 | // described in 13.3.3.2, the ambiguous conversion sequence is |
| 3755 | // treated as a user-defined sequence that is indistinguishable |
| 3756 | // from any other user-defined conversion sequence. |
| 3757 | |
| 3758 | // String literal to 'char *' conversion has been deprecated in C++03. It has |
| 3759 | // been removed from C++11. We still accept this conversion, if it happens at |
| 3760 | // the best viable function. Otherwise, this conversion is considered worse |
| 3761 | // than ellipsis conversion. Consider this as an extension; this is not in the |
| 3762 | // standard. For example: |
| 3763 | // |
| 3764 | // int &f(...); // #1 |
| 3765 | // void f(char*); // #2 |
| 3766 | // void g() { int &r = f("foo"); } |
| 3767 | // |
| 3768 | // In C++03, we pick #2 as the best viable function. |
| 3769 | // In C++11, we pick #1 as the best viable function, because ellipsis |
| 3770 | // conversion is better than string-literal to char* conversion (since there |
| 3771 | // is no such conversion in C++11). If there was no #1 at all or #1 couldn't |
| 3772 | // convert arguments, #2 would be the best viable function in C++11. |
| 3773 | // If the best viable function has this conversion, a warning will be issued |
| 3774 | // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11. |
| 3775 | |
| 3776 | if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings && |
| 3777 | hasDeprecatedStringLiteralToCharPtrConversion(ICS1) != |
| 3778 | hasDeprecatedStringLiteralToCharPtrConversion(ICS2)) |
| 3779 | return hasDeprecatedStringLiteralToCharPtrConversion(ICS1) |
| 3780 | ? ImplicitConversionSequence::Worse |
| 3781 | : ImplicitConversionSequence::Better; |
| 3782 | |
| 3783 | if (ICS1.getKindRank() < ICS2.getKindRank()) |
| 3784 | return ImplicitConversionSequence::Better; |
| 3785 | if (ICS2.getKindRank() < ICS1.getKindRank()) |
| 3786 | return ImplicitConversionSequence::Worse; |
| 3787 | |
| 3788 | // The following checks require both conversion sequences to be of |
| 3789 | // the same kind. |
| 3790 | if (ICS1.getKind() != ICS2.getKind()) |
| 3791 | return ImplicitConversionSequence::Indistinguishable; |
| 3792 | |
| 3793 | ImplicitConversionSequence::CompareKind Result = |
| 3794 | ImplicitConversionSequence::Indistinguishable; |
| 3795 | |
| 3796 | // Two implicit conversion sequences of the same form are |
| 3797 | // indistinguishable conversion sequences unless one of the |
| 3798 | // following rules apply: (C++ 13.3.3.2p3): |
| 3799 | |
| 3800 | // List-initialization sequence L1 is a better conversion sequence than |
| 3801 | // list-initialization sequence L2 if: |
| 3802 | // - L1 converts to std::initializer_list<X> for some X and L2 does not, or, |
| 3803 | // if not that, |
| 3804 | // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T", |
| 3805 | // and N1 is smaller than N2., |
| 3806 | // even if one of the other rules in this paragraph would otherwise apply. |
| 3807 | if (!ICS1.isBad()) { |
| 3808 | if (ICS1.isStdInitializerListElement() && |
| 3809 | !ICS2.isStdInitializerListElement()) |
| 3810 | return ImplicitConversionSequence::Better; |
| 3811 | if (!ICS1.isStdInitializerListElement() && |
| 3812 | ICS2.isStdInitializerListElement()) |
| 3813 | return ImplicitConversionSequence::Worse; |
| 3814 | } |
| 3815 | |
| 3816 | if (ICS1.isStandard()) |
| 3817 | // Standard conversion sequence S1 is a better conversion sequence than |
| 3818 | // standard conversion sequence S2 if [...] |
| 3819 | Result = CompareStandardConversionSequences(S, Loc, |
| 3820 | ICS1.Standard, ICS2.Standard); |
| 3821 | else if (ICS1.isUserDefined()) { |
| 3822 | // User-defined conversion sequence U1 is a better conversion |
| 3823 | // sequence than another user-defined conversion sequence U2 if |
| 3824 | // they contain the same user-defined conversion function or |
| 3825 | // constructor and if the second standard conversion sequence of |
| 3826 | // U1 is better than the second standard conversion sequence of |
| 3827 | // U2 (C++ 13.3.3.2p3). |
| 3828 | if (ICS1.UserDefined.ConversionFunction == |
| 3829 | ICS2.UserDefined.ConversionFunction) |
| 3830 | Result = CompareStandardConversionSequences(S, Loc, |
| 3831 | ICS1.UserDefined.After, |
| 3832 | ICS2.UserDefined.After); |
| 3833 | else |
| 3834 | Result = compareConversionFunctions(S, |
| 3835 | ICS1.UserDefined.ConversionFunction, |
| 3836 | ICS2.UserDefined.ConversionFunction); |
| 3837 | } |
| 3838 | |
| 3839 | return Result; |
| 3840 | } |
| 3841 | |
| 3842 | // Per 13.3.3.2p3, compare the given standard conversion sequences to |
| 3843 | // determine if one is a proper subset of the other. |
| 3844 | static ImplicitConversionSequence::CompareKind |
| 3845 | compareStandardConversionSubsets(ASTContext &Context, |
| 3846 | const StandardConversionSequence& SCS1, |
| 3847 | const StandardConversionSequence& SCS2) { |
| 3848 | ImplicitConversionSequence::CompareKind Result |
| 3849 | = ImplicitConversionSequence::Indistinguishable; |
| 3850 | |
| 3851 | // the identity conversion sequence is considered to be a subsequence of |
| 3852 | // any non-identity conversion sequence |
| 3853 | if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) |
| 3854 | return ImplicitConversionSequence::Better; |
| 3855 | else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) |
| 3856 | return ImplicitConversionSequence::Worse; |
| 3857 | |
| 3858 | if (SCS1.Second != SCS2.Second) { |
| 3859 | if (SCS1.Second == ICK_Identity) |
| 3860 | Result = ImplicitConversionSequence::Better; |
| 3861 | else if (SCS2.Second == ICK_Identity) |
| 3862 | Result = ImplicitConversionSequence::Worse; |
| 3863 | else |
| 3864 | return ImplicitConversionSequence::Indistinguishable; |
| 3865 | } else if (!Context.hasSimilarType(SCS1.getToType(1), SCS2.getToType(1))) |
| 3866 | return ImplicitConversionSequence::Indistinguishable; |
| 3867 | |
| 3868 | if (SCS1.Third == SCS2.Third) { |
| 3869 | return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result |
| 3870 | : ImplicitConversionSequence::Indistinguishable; |
| 3871 | } |
| 3872 | |
| 3873 | if (SCS1.Third == ICK_Identity) |
| 3874 | return Result == ImplicitConversionSequence::Worse |
| 3875 | ? ImplicitConversionSequence::Indistinguishable |
| 3876 | : ImplicitConversionSequence::Better; |
| 3877 | |
| 3878 | if (SCS2.Third == ICK_Identity) |
| 3879 | return Result == ImplicitConversionSequence::Better |
| 3880 | ? ImplicitConversionSequence::Indistinguishable |
| 3881 | : ImplicitConversionSequence::Worse; |
| 3882 | |
| 3883 | return ImplicitConversionSequence::Indistinguishable; |
| 3884 | } |
| 3885 | |
| 3886 | /// Determine whether one of the given reference bindings is better |
| 3887 | /// than the other based on what kind of bindings they are. |
| 3888 | static bool |
| 3889 | isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, |
| 3890 | const StandardConversionSequence &SCS2) { |
| 3891 | // C++0x [over.ics.rank]p3b4: |
| 3892 | // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an |
| 3893 | // implicit object parameter of a non-static member function declared |
| 3894 | // without a ref-qualifier, and *either* S1 binds an rvalue reference |
| 3895 | // to an rvalue and S2 binds an lvalue reference *or S1 binds an |
| 3896 | // lvalue reference to a function lvalue and S2 binds an rvalue |
| 3897 | // reference*. |
| 3898 | // |
| 3899 | // FIXME: Rvalue references. We're going rogue with the above edits, |
| 3900 | // because the semantics in the current C++0x working paper (N3225 at the |
| 3901 | // time of this writing) break the standard definition of std::forward |
| 3902 | // and std::reference_wrapper when dealing with references to functions. |
| 3903 | // Proposed wording changes submitted to CWG for consideration. |
| 3904 | if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || |
| 3905 | SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) |
| 3906 | return false; |
| 3907 | |
| 3908 | return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && |
| 3909 | SCS2.IsLvalueReference) || |
| 3910 | (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && |
| 3911 | !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue); |
| 3912 | } |
| 3913 | |
| 3914 | enum class FixedEnumPromotion { |
| 3915 | None, |
| 3916 | ToUnderlyingType, |
| 3917 | ToPromotedUnderlyingType |
| 3918 | }; |
| 3919 | |
| 3920 | /// Returns kind of fixed enum promotion the \a SCS uses. |
| 3921 | static FixedEnumPromotion |
| 3922 | getFixedEnumPromtion(Sema &S, const StandardConversionSequence &SCS) { |
| 3923 | |
| 3924 | if (SCS.Second != ICK_Integral_Promotion) |
| 3925 | return FixedEnumPromotion::None; |
| 3926 | |
| 3927 | QualType FromType = SCS.getFromType(); |
| 3928 | if (!FromType->isEnumeralType()) |
| 3929 | return FixedEnumPromotion::None; |
| 3930 | |
| 3931 | EnumDecl *Enum = FromType->castAs<EnumType>()->getDecl(); |
| 3932 | if (!Enum->isFixed()) |
| 3933 | return FixedEnumPromotion::None; |
| 3934 | |
| 3935 | QualType UnderlyingType = Enum->getIntegerType(); |
| 3936 | if (S.Context.hasSameType(SCS.getToType(1), UnderlyingType)) |
| 3937 | return FixedEnumPromotion::ToUnderlyingType; |
| 3938 | |
| 3939 | return FixedEnumPromotion::ToPromotedUnderlyingType; |
| 3940 | } |
| 3941 | |
| 3942 | /// CompareStandardConversionSequences - Compare two standard |
| 3943 | /// conversion sequences to determine whether one is better than the |
| 3944 | /// other or if they are indistinguishable (C++ 13.3.3.2p3). |
| 3945 | static ImplicitConversionSequence::CompareKind |
| 3946 | CompareStandardConversionSequences(Sema &S, SourceLocation Loc, |
| 3947 | const StandardConversionSequence& SCS1, |
| 3948 | const StandardConversionSequence& SCS2) |
| 3949 | { |
| 3950 | // Standard conversion sequence S1 is a better conversion sequence |
| 3951 | // than standard conversion sequence S2 if (C++ 13.3.3.2p3): |
| 3952 | |
| 3953 | // -- S1 is a proper subsequence of S2 (comparing the conversion |
| 3954 | // sequences in the canonical form defined by 13.3.3.1.1, |
| 3955 | // excluding any Lvalue Transformation; the identity conversion |
| 3956 | // sequence is considered to be a subsequence of any |
| 3957 | // non-identity conversion sequence) or, if not that, |
| 3958 | if (ImplicitConversionSequence::CompareKind CK |
| 3959 | = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) |
| 3960 | return CK; |
| 3961 | |
| 3962 | // -- the rank of S1 is better than the rank of S2 (by the rules |
| 3963 | // defined below), or, if not that, |
| 3964 | ImplicitConversionRank Rank1 = SCS1.getRank(); |
| 3965 | ImplicitConversionRank Rank2 = SCS2.getRank(); |
| 3966 | if (Rank1 < Rank2) |
| 3967 | return ImplicitConversionSequence::Better; |
| 3968 | else if (Rank2 < Rank1) |
| 3969 | return ImplicitConversionSequence::Worse; |
| 3970 | |
| 3971 | // (C++ 13.3.3.2p4): Two conversion sequences with the same rank |
| 3972 | // are indistinguishable unless one of the following rules |
| 3973 | // applies: |
| 3974 | |
| 3975 | // A conversion that is not a conversion of a pointer, or |
| 3976 | // pointer to member, to bool is better than another conversion |
| 3977 | // that is such a conversion. |
| 3978 | if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) |
| 3979 | return SCS2.isPointerConversionToBool() |
| 3980 | ? ImplicitConversionSequence::Better |
| 3981 | : ImplicitConversionSequence::Worse; |
| 3982 | |
| 3983 | // C++14 [over.ics.rank]p4b2: |
| 3984 | // This is retroactively applied to C++11 by CWG 1601. |
| 3985 | // |
| 3986 | // A conversion that promotes an enumeration whose underlying type is fixed |
| 3987 | // to its underlying type is better than one that promotes to the promoted |
| 3988 | // underlying type, if the two are different. |
| 3989 | FixedEnumPromotion FEP1 = getFixedEnumPromtion(S, SCS1); |
| 3990 | FixedEnumPromotion FEP2 = getFixedEnumPromtion(S, SCS2); |
| 3991 | if (FEP1 != FixedEnumPromotion::None && FEP2 != FixedEnumPromotion::None && |
| 3992 | FEP1 != FEP2) |
| 3993 | return FEP1 == FixedEnumPromotion::ToUnderlyingType |
| 3994 | ? ImplicitConversionSequence::Better |
| 3995 | : ImplicitConversionSequence::Worse; |
| 3996 | |
| 3997 | // C++ [over.ics.rank]p4b2: |
| 3998 | // |
| 3999 | // If class B is derived directly or indirectly from class A, |
| 4000 | // conversion of B* to A* is better than conversion of B* to |
| 4001 | // void*, and conversion of A* to void* is better than conversion |
| 4002 | // of B* to void*. |
| 4003 | bool SCS1ConvertsToVoid |
| 4004 | = SCS1.isPointerConversionToVoidPointer(S.Context); |
| 4005 | bool SCS2ConvertsToVoid |
| 4006 | = SCS2.isPointerConversionToVoidPointer(S.Context); |
| 4007 | if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { |
| 4008 | // Exactly one of the conversion sequences is a conversion to |
| 4009 | // a void pointer; it's the worse conversion. |
| 4010 | return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better |
| 4011 | : ImplicitConversionSequence::Worse; |
| 4012 | } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { |
| 4013 | // Neither conversion sequence converts to a void pointer; compare |
| 4014 | // their derived-to-base conversions. |
| 4015 | if (ImplicitConversionSequence::CompareKind DerivedCK |
| 4016 | = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2)) |
| 4017 | return DerivedCK; |
| 4018 | } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid && |
| 4019 | !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) { |
| 4020 | // Both conversion sequences are conversions to void |
| 4021 | // pointers. Compare the source types to determine if there's an |
| 4022 | // inheritance relationship in their sources. |
| 4023 | QualType FromType1 = SCS1.getFromType(); |
| 4024 | QualType FromType2 = SCS2.getFromType(); |
| 4025 | |
| 4026 | // Adjust the types we're converting from via the array-to-pointer |
| 4027 | // conversion, if we need to. |
| 4028 | if (SCS1.First == ICK_Array_To_Pointer) |
| 4029 | FromType1 = S.Context.getArrayDecayedType(FromType1); |
| 4030 | if (SCS2.First == ICK_Array_To_Pointer) |
| 4031 | FromType2 = S.Context.getArrayDecayedType(FromType2); |
| 4032 | |
| 4033 | QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType(); |
| 4034 | QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType(); |
| 4035 | |
| 4036 | if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1)) |
| 4037 | return ImplicitConversionSequence::Better; |
| 4038 | else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2)) |
| 4039 | return ImplicitConversionSequence::Worse; |
| 4040 | |
| 4041 | // Objective-C++: If one interface is more specific than the |
| 4042 | // other, it is the better one. |
| 4043 | const ObjCObjectPointerType* FromObjCPtr1 |
| 4044 | = FromType1->getAs<ObjCObjectPointerType>(); |
| 4045 | const ObjCObjectPointerType* FromObjCPtr2 |
| 4046 | = FromType2->getAs<ObjCObjectPointerType>(); |
| 4047 | if (FromObjCPtr1 && FromObjCPtr2) { |
| 4048 | bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1, |
| 4049 | FromObjCPtr2); |
| 4050 | bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2, |
| 4051 | FromObjCPtr1); |
| 4052 | if (AssignLeft != AssignRight) { |
| 4053 | return AssignLeft? ImplicitConversionSequence::Better |
| 4054 | : ImplicitConversionSequence::Worse; |
| 4055 | } |
| 4056 | } |
| 4057 | } |
| 4058 | |
| 4059 | if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { |
| 4060 | // Check for a better reference binding based on the kind of bindings. |
| 4061 | if (isBetterReferenceBindingKind(SCS1, SCS2)) |
| 4062 | return ImplicitConversionSequence::Better; |
| 4063 | else if (isBetterReferenceBindingKind(SCS2, SCS1)) |
| 4064 | return ImplicitConversionSequence::Worse; |
| 4065 | } |
| 4066 | |
| 4067 | // Compare based on qualification conversions (C++ 13.3.3.2p3, |
| 4068 | // bullet 3). |
| 4069 | if (ImplicitConversionSequence::CompareKind QualCK |
| 4070 | = CompareQualificationConversions(S, SCS1, SCS2)) |
| 4071 | return QualCK; |
| 4072 | |
| 4073 | if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { |
| 4074 | // C++ [over.ics.rank]p3b4: |
| 4075 | // -- S1 and S2 are reference bindings (8.5.3), and the types to |
| 4076 | // which the references refer are the same type except for |
| 4077 | // top-level cv-qualifiers, and the type to which the reference |
| 4078 | // initialized by S2 refers is more cv-qualified than the type |
| 4079 | // to which the reference initialized by S1 refers. |
| 4080 | QualType T1 = SCS1.getToType(2); |
| 4081 | QualType T2 = SCS2.getToType(2); |
| 4082 | T1 = S.Context.getCanonicalType(T1); |
| 4083 | T2 = S.Context.getCanonicalType(T2); |
| 4084 | Qualifiers T1Quals, T2Quals; |
| 4085 | QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); |
| 4086 | QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); |
| 4087 | if (UnqualT1 == UnqualT2) { |
| 4088 | // Objective-C++ ARC: If the references refer to objects with different |
| 4089 | // lifetimes, prefer bindings that don't change lifetime. |
| 4090 | if (SCS1.ObjCLifetimeConversionBinding != |
| 4091 | SCS2.ObjCLifetimeConversionBinding) { |
| 4092 | return SCS1.ObjCLifetimeConversionBinding |
| 4093 | ? ImplicitConversionSequence::Worse |
| 4094 | : ImplicitConversionSequence::Better; |
| 4095 | } |
| 4096 | |
| 4097 | // If the type is an array type, promote the element qualifiers to the |
| 4098 | // type for comparison. |
| 4099 | if (isa<ArrayType>(T1) && T1Quals) |
| 4100 | T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); |
| 4101 | if (isa<ArrayType>(T2) && T2Quals) |
| 4102 | T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); |
| 4103 | if (T2.isMoreQualifiedThan(T1)) |
| 4104 | return ImplicitConversionSequence::Better; |
| 4105 | if (T1.isMoreQualifiedThan(T2)) |
| 4106 | return ImplicitConversionSequence::Worse; |
| 4107 | } |
| 4108 | } |
| 4109 | |
| 4110 | // In Microsoft mode (below 19.28), prefer an integral conversion to a |
| 4111 | // floating-to-integral conversion if the integral conversion |
| 4112 | // is between types of the same size. |
| 4113 | // For example: |
| 4114 | // void f(float); |
| 4115 | // void f(int); |
| 4116 | // int main { |
| 4117 | // long a; |
| 4118 | // f(a); |
| 4119 | // } |
| 4120 | // Here, MSVC will call f(int) instead of generating a compile error |
| 4121 | // as clang will do in standard mode. |
| 4122 | if (S.getLangOpts().MSVCCompat && |
| 4123 | !S.getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2019_8) && |
| 4124 | SCS1.Second == ICK_Integral_Conversion && |
| 4125 | SCS2.Second == ICK_Floating_Integral && |
| 4126 | S.Context.getTypeSize(SCS1.getFromType()) == |
| 4127 | S.Context.getTypeSize(SCS1.getToType(2))) |
| 4128 | return ImplicitConversionSequence::Better; |
| 4129 | |
| 4130 | // Prefer a compatible vector conversion over a lax vector conversion |
| 4131 | // For example: |
| 4132 | // |
| 4133 | // typedef float __v4sf __attribute__((__vector_size__(16))); |
| 4134 | // void f(vector float); |
| 4135 | // void f(vector signed int); |
| 4136 | // int main() { |
| 4137 | // __v4sf a; |
| 4138 | // f(a); |
| 4139 | // } |
| 4140 | // Here, we'd like to choose f(vector float) and not |
| 4141 | // report an ambiguous call error |
| 4142 | if (SCS1.Second == ICK_Vector_Conversion && |
| 4143 | SCS2.Second == ICK_Vector_Conversion) { |
| 4144 | bool SCS1IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes( |
| 4145 | SCS1.getFromType(), SCS1.getToType(2)); |
| 4146 | bool SCS2IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes( |
| 4147 | SCS2.getFromType(), SCS2.getToType(2)); |
| 4148 | |
| 4149 | if (SCS1IsCompatibleVectorConversion != SCS2IsCompatibleVectorConversion) |
| 4150 | return SCS1IsCompatibleVectorConversion |
| 4151 | ? ImplicitConversionSequence::Better |
| 4152 | : ImplicitConversionSequence::Worse; |
| 4153 | } |
| 4154 | |
| 4155 | if (SCS1.Second == ICK_SVE_Vector_Conversion && |
| 4156 | SCS2.Second == ICK_SVE_Vector_Conversion) { |
| 4157 | bool SCS1IsCompatibleSVEVectorConversion = |
| 4158 | S.Context.areCompatibleSveTypes(SCS1.getFromType(), SCS1.getToType(2)); |
| 4159 | bool SCS2IsCompatibleSVEVectorConversion = |
| 4160 | S.Context.areCompatibleSveTypes(SCS2.getFromType(), SCS2.getToType(2)); |
| 4161 | |
| 4162 | if (SCS1IsCompatibleSVEVectorConversion != |
| 4163 | SCS2IsCompatibleSVEVectorConversion) |
| 4164 | return SCS1IsCompatibleSVEVectorConversion |
| 4165 | ? ImplicitConversionSequence::Better |
| 4166 | : ImplicitConversionSequence::Worse; |
| 4167 | } |
| 4168 | |
| 4169 | return ImplicitConversionSequence::Indistinguishable; |
| 4170 | } |
| 4171 | |
| 4172 | /// CompareQualificationConversions - Compares two standard conversion |
| 4173 | /// sequences to determine whether they can be ranked based on their |
| 4174 | /// qualification conversions (C++ 13.3.3.2p3 bullet 3). |
| 4175 | static ImplicitConversionSequence::CompareKind |
| 4176 | CompareQualificationConversions(Sema &S, |
| 4177 | const StandardConversionSequence& SCS1, |
| 4178 | const StandardConversionSequence& SCS2) { |
| 4179 | // C++ 13.3.3.2p3: |
| 4180 | // -- S1 and S2 differ only in their qualification conversion and |
| 4181 | // yield similar types T1 and T2 (C++ 4.4), respectively, and the |
| 4182 | // cv-qualification signature of type T1 is a proper subset of |
| 4183 | // the cv-qualification signature of type T2, and S1 is not the |
| 4184 | // deprecated string literal array-to-pointer conversion (4.2). |
| 4185 | if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || |
| 4186 | SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) |
| 4187 | return ImplicitConversionSequence::Indistinguishable; |
| 4188 | |
| 4189 | // FIXME: the example in the standard doesn't use a qualification |
| 4190 | // conversion (!) |
| 4191 | QualType T1 = SCS1.getToType(2); |
| 4192 | QualType T2 = SCS2.getToType(2); |
| 4193 | T1 = S.Context.getCanonicalType(T1); |
| 4194 | T2 = S.Context.getCanonicalType(T2); |
| 4195 | assert(!T1->isReferenceType() && !T2->isReferenceType())((void)0); |
| 4196 | Qualifiers T1Quals, T2Quals; |
| 4197 | QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); |
| 4198 | QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); |
| 4199 | |
| 4200 | // If the types are the same, we won't learn anything by unwrapping |
| 4201 | // them. |
| 4202 | if (UnqualT1 == UnqualT2) |
| 4203 | return ImplicitConversionSequence::Indistinguishable; |
| 4204 | |
| 4205 | ImplicitConversionSequence::CompareKind Result |
| 4206 | = ImplicitConversionSequence::Indistinguishable; |
| 4207 | |
| 4208 | // Objective-C++ ARC: |
| 4209 | // Prefer qualification conversions not involving a change in lifetime |
| 4210 | // to qualification conversions that do not change lifetime. |
| 4211 | if (SCS1.QualificationIncludesObjCLifetime != |
| 4212 | SCS2.QualificationIncludesObjCLifetime) { |
| 4213 | Result = SCS1.QualificationIncludesObjCLifetime |
| 4214 | ? ImplicitConversionSequence::Worse |
| 4215 | : ImplicitConversionSequence::Better; |
| 4216 | } |
| 4217 | |
| 4218 | while (S.Context.UnwrapSimilarTypes(T1, T2)) { |
| 4219 | // Within each iteration of the loop, we check the qualifiers to |
| 4220 | // determine if this still looks like a qualification |
| 4221 | // conversion. Then, if all is well, we unwrap one more level of |
| 4222 | // pointers or pointers-to-members and do it all again |
| 4223 | // until there are no more pointers or pointers-to-members left |
| 4224 | // to unwrap. This essentially mimics what |
| 4225 | // IsQualificationConversion does, but here we're checking for a |
| 4226 | // strict subset of qualifiers. |
| 4227 | if (T1.getQualifiers().withoutObjCLifetime() == |
| 4228 | T2.getQualifiers().withoutObjCLifetime()) |
| 4229 | // The qualifiers are the same, so this doesn't tell us anything |
| 4230 | // about how the sequences rank. |
| 4231 | // ObjC ownership quals are omitted above as they interfere with |
| 4232 | // the ARC overload rule. |
| 4233 | ; |
| 4234 | else if (T2.isMoreQualifiedThan(T1)) { |
| 4235 | // T1 has fewer qualifiers, so it could be the better sequence. |
| 4236 | if (Result == ImplicitConversionSequence::Worse) |
| 4237 | // Neither has qualifiers that are a subset of the other's |
| 4238 | // qualifiers. |
| 4239 | return ImplicitConversionSequence::Indistinguishable; |
| 4240 | |
| 4241 | Result = ImplicitConversionSequence::Better; |
| 4242 | } else if (T1.isMoreQualifiedThan(T2)) { |
| 4243 | // T2 has fewer qualifiers, so it could be the better sequence. |
| 4244 | if (Result == ImplicitConversionSequence::Better) |
| 4245 | // Neither has qualifiers that are a subset of the other's |
| 4246 | // qualifiers. |
| 4247 | return ImplicitConversionSequence::Indistinguishable; |
| 4248 | |
| 4249 | Result = ImplicitConversionSequence::Worse; |
| 4250 | } else { |
| 4251 | // Qualifiers are disjoint. |
| 4252 | return ImplicitConversionSequence::Indistinguishable; |
| 4253 | } |
| 4254 | |
| 4255 | // If the types after this point are equivalent, we're done. |
| 4256 | if (S.Context.hasSameUnqualifiedType(T1, T2)) |
| 4257 | break; |
| 4258 | } |
| 4259 | |
| 4260 | // Check that the winning standard conversion sequence isn't using |
| 4261 | // the deprecated string literal array to pointer conversion. |
| 4262 | switch (Result) { |
| 4263 | case ImplicitConversionSequence::Better: |
| 4264 | if (SCS1.DeprecatedStringLiteralToCharPtr) |
| 4265 | Result = ImplicitConversionSequence::Indistinguishable; |
| 4266 | break; |
| 4267 | |
| 4268 | case ImplicitConversionSequence::Indistinguishable: |
| 4269 | break; |
| 4270 | |
| 4271 | case ImplicitConversionSequence::Worse: |
| 4272 | if (SCS2.DeprecatedStringLiteralToCharPtr) |
| 4273 | Result = ImplicitConversionSequence::Indistinguishable; |
| 4274 | break; |
| 4275 | } |
| 4276 | |
| 4277 | return Result; |
| 4278 | } |
| 4279 | |
| 4280 | /// CompareDerivedToBaseConversions - Compares two standard conversion |
| 4281 | /// sequences to determine whether they can be ranked based on their |
| 4282 | /// various kinds of derived-to-base conversions (C++ |
| 4283 | /// [over.ics.rank]p4b3). As part of these checks, we also look at |
| 4284 | /// conversions between Objective-C interface types. |
| 4285 | static ImplicitConversionSequence::CompareKind |
| 4286 | CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc, |
| 4287 | const StandardConversionSequence& SCS1, |
| 4288 | const StandardConversionSequence& SCS2) { |
| 4289 | QualType FromType1 = SCS1.getFromType(); |
| 4290 | QualType ToType1 = SCS1.getToType(1); |
| 4291 | QualType FromType2 = SCS2.getFromType(); |
| 4292 | QualType ToType2 = SCS2.getToType(1); |
| 4293 | |
| 4294 | // Adjust the types we're converting from via the array-to-pointer |
| 4295 | // conversion, if we need to. |
| 4296 | if (SCS1.First == ICK_Array_To_Pointer) |
| 4297 | FromType1 = S.Context.getArrayDecayedType(FromType1); |
| 4298 | if (SCS2.First == ICK_Array_To_Pointer) |
| 4299 | FromType2 = S.Context.getArrayDecayedType(FromType2); |
| 4300 | |
| 4301 | // Canonicalize all of the types. |
| 4302 | FromType1 = S.Context.getCanonicalType(FromType1); |
| 4303 | ToType1 = S.Context.getCanonicalType(ToType1); |
| 4304 | FromType2 = S.Context.getCanonicalType(FromType2); |
| 4305 | ToType2 = S.Context.getCanonicalType(ToType2); |
| 4306 | |
| 4307 | // C++ [over.ics.rank]p4b3: |
| 4308 | // |
| 4309 | // If class B is derived directly or indirectly from class A and |
| 4310 | // class C is derived directly or indirectly from B, |
| 4311 | // |
| 4312 | // Compare based on pointer conversions. |
| 4313 | if (SCS1.Second == ICK_Pointer_Conversion && |
| 4314 | SCS2.Second == ICK_Pointer_Conversion && |
| 4315 | /*FIXME: Remove if Objective-C id conversions get their own rank*/ |
| 4316 | FromType1->isPointerType() && FromType2->isPointerType() && |
| 4317 | ToType1->isPointerType() && ToType2->isPointerType()) { |
| 4318 | QualType FromPointee1 = |
| 4319 | FromType1->castAs<PointerType>()->getPointeeType().getUnqualifiedType(); |
| 4320 | QualType ToPointee1 = |
| 4321 | ToType1->castAs<PointerType>()->getPointeeType().getUnqualifiedType(); |
| 4322 | QualType FromPointee2 = |
| 4323 | FromType2->castAs<PointerType>()->getPointeeType().getUnqualifiedType(); |
| 4324 | QualType ToPointee2 = |
| 4325 | ToType2->castAs<PointerType>()->getPointeeType().getUnqualifiedType(); |
| 4326 | |
| 4327 | // -- conversion of C* to B* is better than conversion of C* to A*, |
| 4328 | if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { |
| 4329 | if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2)) |
| 4330 | return ImplicitConversionSequence::Better; |
| 4331 | else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1)) |
| 4332 | return ImplicitConversionSequence::Worse; |
| 4333 | } |
| 4334 | |
| 4335 | // -- conversion of B* to A* is better than conversion of C* to A*, |
| 4336 | if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { |
| 4337 | if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1)) |
| 4338 | return ImplicitConversionSequence::Better; |
| 4339 | else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2)) |
| 4340 | return ImplicitConversionSequence::Worse; |
| 4341 | } |
| 4342 | } else if (SCS1.Second == ICK_Pointer_Conversion && |
| 4343 | SCS2.Second == ICK_Pointer_Conversion) { |
| 4344 | const ObjCObjectPointerType *FromPtr1 |
| 4345 | = FromType1->getAs<ObjCObjectPointerType>(); |
| 4346 | const ObjCObjectPointerType *FromPtr2 |
| 4347 | = FromType2->getAs<ObjCObjectPointerType>(); |
| 4348 | const ObjCObjectPointerType *ToPtr1 |
| 4349 | = ToType1->getAs<ObjCObjectPointerType>(); |
| 4350 | const ObjCObjectPointerType *ToPtr2 |
| 4351 | = ToType2->getAs<ObjCObjectPointerType>(); |
| 4352 | |
| 4353 | if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { |
| 4354 | // Apply the same conversion ranking rules for Objective-C pointer types |
| 4355 | // that we do for C++ pointers to class types. However, we employ the |
| 4356 | // Objective-C pseudo-subtyping relationship used for assignment of |
| 4357 | // Objective-C pointer types. |
| 4358 | bool FromAssignLeft |
| 4359 | = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); |
| 4360 | bool FromAssignRight |
| 4361 | = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); |
| 4362 | bool ToAssignLeft |
| 4363 | = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); |
| 4364 | bool ToAssignRight |
| 4365 | = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); |
| 4366 | |
| 4367 | // A conversion to an a non-id object pointer type or qualified 'id' |
| 4368 | // type is better than a conversion to 'id'. |
| 4369 | if (ToPtr1->isObjCIdType() && |
| 4370 | (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) |
| 4371 | return ImplicitConversionSequence::Worse; |
| 4372 | if (ToPtr2->isObjCIdType() && |
| 4373 | (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) |
| 4374 | return ImplicitConversionSequence::Better; |
| 4375 | |
| 4376 | // A conversion to a non-id object pointer type is better than a |
| 4377 | // conversion to a qualified 'id' type |
| 4378 | if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) |
| 4379 | return ImplicitConversionSequence::Worse; |
| 4380 | if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) |
| 4381 | return ImplicitConversionSequence::Better; |
| 4382 | |
| 4383 | // A conversion to an a non-Class object pointer type or qualified 'Class' |
| 4384 | // type is better than a conversion to 'Class'. |
| 4385 | if (ToPtr1->isObjCClassType() && |
| 4386 | (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) |
| 4387 | return ImplicitConversionSequence::Worse; |
| 4388 | if (ToPtr2->isObjCClassType() && |
| 4389 | (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) |
| 4390 | return ImplicitConversionSequence::Better; |
| 4391 | |
| 4392 | // A conversion to a non-Class object pointer type is better than a |
| 4393 | // conversion to a qualified 'Class' type. |
| 4394 | if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) |
| 4395 | return ImplicitConversionSequence::Worse; |
| 4396 | if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) |
| 4397 | return ImplicitConversionSequence::Better; |
| 4398 | |
| 4399 | // -- "conversion of C* to B* is better than conversion of C* to A*," |
| 4400 | if (S.Context.hasSameType(FromType1, FromType2) && |
| 4401 | !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && |
| 4402 | (ToAssignLeft != ToAssignRight)) { |
| 4403 | if (FromPtr1->isSpecialized()) { |
| 4404 | // "conversion of B<A> * to B * is better than conversion of B * to |
| 4405 | // C *. |
| 4406 | bool IsFirstSame = |
| 4407 | FromPtr1->getInterfaceDecl() == ToPtr1->getInterfaceDecl(); |
| 4408 | bool IsSecondSame = |
| 4409 | FromPtr1->getInterfaceDecl() == ToPtr2->getInterfaceDecl(); |
| 4410 | if (IsFirstSame) { |
| 4411 | if (!IsSecondSame) |
| 4412 | return ImplicitConversionSequence::Better; |
| 4413 | } else if (IsSecondSame) |
| 4414 | return ImplicitConversionSequence::Worse; |
| 4415 | } |
| 4416 | return ToAssignLeft? ImplicitConversionSequence::Worse |
| 4417 | : ImplicitConversionSequence::Better; |
| 4418 | } |
| 4419 | |
| 4420 | // -- "conversion of B* to A* is better than conversion of C* to A*," |
| 4421 | if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && |
| 4422 | (FromAssignLeft != FromAssignRight)) |
| 4423 | return FromAssignLeft? ImplicitConversionSequence::Better |
| 4424 | : ImplicitConversionSequence::Worse; |
| 4425 | } |
| 4426 | } |
| 4427 | |
| 4428 | // Ranking of member-pointer types. |
| 4429 | if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && |
| 4430 | FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && |
| 4431 | ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { |
| 4432 | const auto *FromMemPointer1 = FromType1->castAs<MemberPointerType>(); |
| 4433 | const auto *ToMemPointer1 = ToType1->castAs<MemberPointerType>(); |
| 4434 | const auto *FromMemPointer2 = FromType2->castAs<MemberPointerType>(); |
| 4435 | const auto *ToMemPointer2 = ToType2->castAs<MemberPointerType>(); |
| 4436 | const Type *FromPointeeType1 = FromMemPointer1->getClass(); |
| 4437 | const Type *ToPointeeType1 = ToMemPointer1->getClass(); |
| 4438 | const Type *FromPointeeType2 = FromMemPointer2->getClass(); |
| 4439 | const Type *ToPointeeType2 = ToMemPointer2->getClass(); |
| 4440 | QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); |
| 4441 | QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); |
| 4442 | QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); |
| 4443 | QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); |
| 4444 | // conversion of A::* to B::* is better than conversion of A::* to C::*, |
| 4445 | if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { |
| 4446 | if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2)) |
| 4447 | return ImplicitConversionSequence::Worse; |
| 4448 | else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1)) |
| 4449 | return ImplicitConversionSequence::Better; |
| 4450 | } |
| 4451 | // conversion of B::* to C::* is better than conversion of A::* to C::* |
| 4452 | if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { |
| 4453 | if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2)) |
| 4454 | return ImplicitConversionSequence::Better; |
| 4455 | else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1)) |
| 4456 | return ImplicitConversionSequence::Worse; |
| 4457 | } |
| 4458 | } |
| 4459 | |
| 4460 | if (SCS1.Second == ICK_Derived_To_Base) { |
| 4461 | // -- conversion of C to B is better than conversion of C to A, |
| 4462 | // -- binding of an expression of type C to a reference of type |
| 4463 | // B& is better than binding an expression of type C to a |
| 4464 | // reference of type A&, |
| 4465 | if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && |
| 4466 | !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { |
| 4467 | if (S.IsDerivedFrom(Loc, ToType1, ToType2)) |
| 4468 | return ImplicitConversionSequence::Better; |
| 4469 | else if (S.IsDerivedFrom(Loc, ToType2, ToType1)) |
| 4470 | return ImplicitConversionSequence::Worse; |
| 4471 | } |
| 4472 | |
| 4473 | // -- conversion of B to A is better than conversion of C to A. |
| 4474 | // -- binding of an expression of type B to a reference of type |
| 4475 | // A& is better than binding an expression of type C to a |
| 4476 | // reference of type A&, |
| 4477 | if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && |
| 4478 | S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { |
| 4479 | if (S.IsDerivedFrom(Loc, FromType2, FromType1)) |
| 4480 | return ImplicitConversionSequence::Better; |
| 4481 | else if (S.IsDerivedFrom(Loc, FromType1, FromType2)) |
| 4482 | return ImplicitConversionSequence::Worse; |
| 4483 | } |
| 4484 | } |
| 4485 | |
| 4486 | return ImplicitConversionSequence::Indistinguishable; |
| 4487 | } |
| 4488 | |
| 4489 | /// Determine whether the given type is valid, e.g., it is not an invalid |
| 4490 | /// C++ class. |
| 4491 | static bool isTypeValid(QualType T) { |
| 4492 | if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) |
| 4493 | return !Record->isInvalidDecl(); |
| 4494 | |
| 4495 | return true; |
| 4496 | } |
| 4497 | |
| 4498 | static QualType withoutUnaligned(ASTContext &Ctx, QualType T) { |
| 4499 | if (!T.getQualifiers().hasUnaligned()) |
| 4500 | return T; |
| 4501 | |
| 4502 | Qualifiers Q; |
| 4503 | T = Ctx.getUnqualifiedArrayType(T, Q); |
| 4504 | Q.removeUnaligned(); |
| 4505 | return Ctx.getQualifiedType(T, Q); |
| 4506 | } |
| 4507 | |
| 4508 | /// CompareReferenceRelationship - Compare the two types T1 and T2 to |
| 4509 | /// determine whether they are reference-compatible, |
| 4510 | /// reference-related, or incompatible, for use in C++ initialization by |
| 4511 | /// reference (C++ [dcl.ref.init]p4). Neither type can be a reference |
| 4512 | /// type, and the first type (T1) is the pointee type of the reference |
| 4513 | /// type being initialized. |
| 4514 | Sema::ReferenceCompareResult |
| 4515 | Sema::CompareReferenceRelationship(SourceLocation Loc, |
| 4516 | QualType OrigT1, QualType OrigT2, |
| 4517 | ReferenceConversions *ConvOut) { |
| 4518 | assert(!OrigT1->isReferenceType() &&((void)0) |
| 4519 | "T1 must be the pointee type of the reference type")((void)0); |
| 4520 | assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type")((void)0); |
| 4521 | |
| 4522 | QualType T1 = Context.getCanonicalType(OrigT1); |
| 4523 | QualType T2 = Context.getCanonicalType(OrigT2); |
| 4524 | Qualifiers T1Quals, T2Quals; |
| 4525 | QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); |
| 4526 | QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); |
| 4527 | |
| 4528 | ReferenceConversions ConvTmp; |
| 4529 | ReferenceConversions &Conv = ConvOut ? *ConvOut : ConvTmp; |
| 4530 | Conv = ReferenceConversions(); |
| 4531 | |
| 4532 | // C++2a [dcl.init.ref]p4: |
| 4533 | // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is |
| 4534 | // reference-related to "cv2 T2" if T1 is similar to T2, or |
| 4535 | // T1 is a base class of T2. |
| 4536 | // "cv1 T1" is reference-compatible with "cv2 T2" if |
| 4537 | // a prvalue of type "pointer to cv2 T2" can be converted to the type |
| 4538 | // "pointer to cv1 T1" via a standard conversion sequence. |
| 4539 | |
| 4540 | // Check for standard conversions we can apply to pointers: derived-to-base |
| 4541 | // conversions, ObjC pointer conversions, and function pointer conversions. |
| 4542 | // (Qualification conversions are checked last.) |
| 4543 | QualType ConvertedT2; |
| 4544 | if (UnqualT1 == UnqualT2) { |
| 4545 | // Nothing to do. |
| 4546 | } else if (isCompleteType(Loc, OrigT2) && |
| 4547 | isTypeValid(UnqualT1) && isTypeValid(UnqualT2) && |
| 4548 | IsDerivedFrom(Loc, UnqualT2, UnqualT1)) |
| 4549 | Conv |= ReferenceConversions::DerivedToBase; |
| 4550 | else if (UnqualT1->isObjCObjectOrInterfaceType() && |
| 4551 | UnqualT2->isObjCObjectOrInterfaceType() && |
| 4552 | Context.canBindObjCObjectType(UnqualT1, UnqualT2)) |
| 4553 | Conv |= ReferenceConversions::ObjC; |
| 4554 | else if (UnqualT2->isFunctionType() && |
| 4555 | IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2)) { |
| 4556 | Conv |= ReferenceConversions::Function; |
| 4557 | // No need to check qualifiers; function types don't have them. |
| 4558 | return Ref_Compatible; |
| 4559 | } |
| 4560 | bool ConvertedReferent = Conv != 0; |
| 4561 | |
| 4562 | // We can have a qualification conversion. Compute whether the types are |
| 4563 | // similar at the same time. |
| 4564 | bool PreviousToQualsIncludeConst = true; |
| 4565 | bool TopLevel = true; |
| 4566 | do { |
| 4567 | if (T1 == T2) |
| 4568 | break; |
| 4569 | |
| 4570 | // We will need a qualification conversion. |
| 4571 | Conv |= ReferenceConversions::Qualification; |
| 4572 | |
| 4573 | // Track whether we performed a qualification conversion anywhere other |
| 4574 | // than the top level. This matters for ranking reference bindings in |
| 4575 | // overload resolution. |
| 4576 | if (!TopLevel) |
| 4577 | Conv |= ReferenceConversions::NestedQualification; |
| 4578 | |
| 4579 | // MS compiler ignores __unaligned qualifier for references; do the same. |
| 4580 | T1 = withoutUnaligned(Context, T1); |
| 4581 | T2 = withoutUnaligned(Context, T2); |
| 4582 | |
| 4583 | // If we find a qualifier mismatch, the types are not reference-compatible, |
| 4584 | // but are still be reference-related if they're similar. |
| 4585 | bool ObjCLifetimeConversion = false; |
| 4586 | if (!isQualificationConversionStep(T2, T1, /*CStyle=*/false, TopLevel, |
| 4587 | PreviousToQualsIncludeConst, |
| 4588 | ObjCLifetimeConversion)) |
| 4589 | return (ConvertedReferent || Context.hasSimilarType(T1, T2)) |
| 4590 | ? Ref_Related |
| 4591 | : Ref_Incompatible; |
| 4592 | |
| 4593 | // FIXME: Should we track this for any level other than the first? |
| 4594 | if (ObjCLifetimeConversion) |
| 4595 | Conv |= ReferenceConversions::ObjCLifetime; |
| 4596 | |
| 4597 | TopLevel = false; |
| 4598 | } while (Context.UnwrapSimilarTypes(T1, T2)); |
| 4599 | |
| 4600 | // At this point, if the types are reference-related, we must either have the |
| 4601 | // same inner type (ignoring qualifiers), or must have already worked out how |
| 4602 | // to convert the referent. |
| 4603 | return (ConvertedReferent || Context.hasSameUnqualifiedType(T1, T2)) |
| 4604 | ? Ref_Compatible |
| 4605 | : Ref_Incompatible; |
| 4606 | } |
| 4607 | |
| 4608 | /// Look for a user-defined conversion to a value reference-compatible |
| 4609 | /// with DeclType. Return true if something definite is found. |
| 4610 | static bool |
| 4611 | FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, |
| 4612 | QualType DeclType, SourceLocation DeclLoc, |
| 4613 | Expr *Init, QualType T2, bool AllowRvalues, |
| 4614 | bool AllowExplicit) { |
| 4615 | assert(T2->isRecordType() && "Can only find conversions of record types.")((void)0); |
| 4616 | auto *T2RecordDecl = cast<CXXRecordDecl>(T2->castAs<RecordType>()->getDecl()); |
| 4617 | |
| 4618 | OverloadCandidateSet CandidateSet( |
| 4619 | DeclLoc, OverloadCandidateSet::CSK_InitByUserDefinedConversion); |
| 4620 | const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions(); |
| 4621 | for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) { |
| 4622 | NamedDecl *D = *I; |
| 4623 | CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); |
| 4624 | if (isa<UsingShadowDecl>(D)) |
| 4625 | D = cast<UsingShadowDecl>(D)->getTargetDecl(); |
| 4626 | |
| 4627 | FunctionTemplateDecl *ConvTemplate |
| 4628 | = dyn_cast<FunctionTemplateDecl>(D); |
| 4629 | CXXConversionDecl *Conv; |
| 4630 | if (ConvTemplate) |
| 4631 | Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); |
| 4632 | else |
| 4633 | Conv = cast<CXXConversionDecl>(D); |
| 4634 | |
| 4635 | if (AllowRvalues) { |
| 4636 | // If we are initializing an rvalue reference, don't permit conversion |
| 4637 | // functions that return lvalues. |
| 4638 | if (!ConvTemplate && DeclType->isRValueReferenceType()) { |
| 4639 | const ReferenceType *RefType |
| 4640 | = Conv->getConversionType()->getAs<LValueReferenceType>(); |
| 4641 | if (RefType && !RefType->getPointeeType()->isFunctionType()) |
| 4642 | continue; |
| 4643 | } |
| 4644 | |
| 4645 | if (!ConvTemplate && |
| 4646 | S.CompareReferenceRelationship( |
| 4647 | DeclLoc, |
| 4648 | Conv->getConversionType() |
| 4649 | .getNonReferenceType() |
| 4650 | .getUnqualifiedType(), |
| 4651 | DeclType.getNonReferenceType().getUnqualifiedType()) == |
| 4652 | Sema::Ref_Incompatible) |
| 4653 | continue; |
| 4654 | } else { |
| 4655 | // If the conversion function doesn't return a reference type, |
| 4656 | // it can't be considered for this conversion. An rvalue reference |
| 4657 | // is only acceptable if its referencee is a function type. |
| 4658 | |
| 4659 | const ReferenceType *RefType = |
| 4660 | Conv->getConversionType()->getAs<ReferenceType>(); |
| 4661 | if (!RefType || |
| 4662 | (!RefType->isLValueReferenceType() && |
| 4663 | !RefType->getPointeeType()->isFunctionType())) |
| 4664 | continue; |
| 4665 | } |
| 4666 | |
| 4667 | if (ConvTemplate) |
| 4668 | S.AddTemplateConversionCandidate( |
| 4669 | ConvTemplate, I.getPair(), ActingDC, Init, DeclType, CandidateSet, |
| 4670 | /*AllowObjCConversionOnExplicit=*/false, AllowExplicit); |
| 4671 | else |
| 4672 | S.AddConversionCandidate( |
| 4673 | Conv, I.getPair(), ActingDC, Init, DeclType, CandidateSet, |
| 4674 | /*AllowObjCConversionOnExplicit=*/false, AllowExplicit); |
| 4675 | } |
| 4676 | |
| 4677 | bool HadMultipleCandidates = (CandidateSet.size() > 1); |
| 4678 | |
| 4679 | OverloadCandidateSet::iterator Best; |
| 4680 | switch (CandidateSet.BestViableFunction(S, DeclLoc, Best)) { |
| 4681 | case OR_Success: |
| 4682 | // C++ [over.ics.ref]p1: |
| 4683 | // |
| 4684 | // [...] If the parameter binds directly to the result of |
| 4685 | // applying a conversion function to the argument |
| 4686 | // expression, the implicit conversion sequence is a |
| 4687 | // user-defined conversion sequence (13.3.3.1.2), with the |
| 4688 | // second standard conversion sequence either an identity |
| 4689 | // conversion or, if the conversion function returns an |
| 4690 | // entity of a type that is a derived class of the parameter |
| 4691 | // type, a derived-to-base Conversion. |
| 4692 | if (!Best->FinalConversion.DirectBinding) |
| 4693 | return false; |
| 4694 | |
| 4695 | ICS.setUserDefined(); |
| 4696 | ICS.UserDefined.Before = Best->Conversions[0].Standard; |
| 4697 | ICS.UserDefined.After = Best->FinalConversion; |
| 4698 | ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates; |
| 4699 | ICS.UserDefined.ConversionFunction = Best->Function; |
| 4700 | ICS.UserDefined.FoundConversionFunction = Best->FoundDecl; |
| 4701 | ICS.UserDefined.EllipsisConversion = false; |
| 4702 | assert(ICS.UserDefined.After.ReferenceBinding &&((void)0) |
| 4703 | ICS.UserDefined.After.DirectBinding &&((void)0) |
| 4704 | "Expected a direct reference binding!")((void)0); |
| 4705 | return true; |
| 4706 | |
| 4707 | case OR_Ambiguous: |
| 4708 | ICS.setAmbiguous(); |
| 4709 | for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); |
| 4710 | Cand != CandidateSet.end(); ++Cand) |
| 4711 | if (Cand->Best) |
| 4712 | ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function); |
| 4713 | return true; |
| 4714 | |
| 4715 | case OR_No_Viable_Function: |
| 4716 | case OR_Deleted: |
| 4717 | // There was no suitable conversion, or we found a deleted |
| 4718 | // conversion; continue with other checks. |
| 4719 | return false; |
| 4720 | } |
| 4721 | |
| 4722 | llvm_unreachable("Invalid OverloadResult!")__builtin_unreachable(); |
| 4723 | } |
| 4724 | |
| 4725 | /// Compute an implicit conversion sequence for reference |
| 4726 | /// initialization. |
| 4727 | static ImplicitConversionSequence |
| 4728 | TryReferenceInit(Sema &S, Expr *Init, QualType DeclType, |
| 4729 | SourceLocation DeclLoc, |
| 4730 | bool SuppressUserConversions, |
| 4731 | bool AllowExplicit) { |
| 4732 | assert(DeclType->isReferenceType() && "Reference init needs a reference")((void)0); |
| 4733 | |
| 4734 | // Most paths end in a failed conversion. |
| 4735 | ImplicitConversionSequence ICS; |
| 4736 | ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); |
| 4737 | |
| 4738 | QualType T1 = DeclType->castAs<ReferenceType>()->getPointeeType(); |
| 4739 | QualType T2 = Init->getType(); |
| 4740 | |
| 4741 | // If the initializer is the address of an overloaded function, try |
| 4742 | // to resolve the overloaded function. If all goes well, T2 is the |
| 4743 | // type of the resulting function. |
| 4744 | if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { |
| 4745 | DeclAccessPair Found; |
| 4746 | if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, |
| 4747 | false, Found)) |
| 4748 | T2 = Fn->getType(); |
| 4749 | } |
| 4750 | |
| 4751 | // Compute some basic properties of the types and the initializer. |
| 4752 | bool isRValRef = DeclType->isRValueReferenceType(); |
| 4753 | Expr::Classification InitCategory = Init->Classify(S.Context); |
| 4754 | |
| 4755 | Sema::ReferenceConversions RefConv; |
| 4756 | Sema::ReferenceCompareResult RefRelationship = |
| 4757 | S.CompareReferenceRelationship(DeclLoc, T1, T2, &RefConv); |
| 4758 | |
| 4759 | auto SetAsReferenceBinding = [&](bool BindsDirectly) { |
| 4760 | ICS.setStandard(); |
| 4761 | ICS.Standard.First = ICK_Identity; |
| 4762 | // FIXME: A reference binding can be a function conversion too. We should |
| 4763 | // consider that when ordering reference-to-function bindings. |
| 4764 | ICS.Standard.Second = (RefConv & Sema::ReferenceConversions::DerivedToBase) |
| 4765 | ? ICK_Derived_To_Base |
| 4766 | : (RefConv & Sema::ReferenceConversions::ObjC) |
| 4767 | ? ICK_Compatible_Conversion |
| 4768 | : ICK_Identity; |
| 4769 | // FIXME: As a speculative fix to a defect introduced by CWG2352, we rank |
| 4770 | // a reference binding that performs a non-top-level qualification |
| 4771 | // conversion as a qualification conversion, not as an identity conversion. |
| 4772 | ICS.Standard.Third = (RefConv & |
| 4773 | Sema::ReferenceConversions::NestedQualification) |
| 4774 | ? ICK_Qualification |
| 4775 | : ICK_Identity; |
| 4776 | ICS.Standard.setFromType(T2); |
| 4777 | ICS.Standard.setToType(0, T2); |
| 4778 | ICS.Standard.setToType(1, T1); |
| 4779 | ICS.Standard.setToType(2, T1); |
| 4780 | ICS.Standard.ReferenceBinding = true; |
| 4781 | ICS.Standard.DirectBinding = BindsDirectly; |
| 4782 | ICS.Standard.IsLvalueReference = !isRValRef; |
| 4783 | ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); |
| 4784 | ICS.Standard.BindsToRvalue = InitCategory.isRValue(); |
| 4785 | ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; |
| 4786 | ICS.Standard.ObjCLifetimeConversionBinding = |
| 4787 | (RefConv & Sema::ReferenceConversions::ObjCLifetime) != 0; |
| 4788 | ICS.Standard.CopyConstructor = nullptr; |
| 4789 | ICS.Standard.DeprecatedStringLiteralToCharPtr = false; |
| 4790 | }; |
| 4791 | |
| 4792 | // C++0x [dcl.init.ref]p5: |
| 4793 | // A reference to type "cv1 T1" is initialized by an expression |
| 4794 | // of type "cv2 T2" as follows: |
| 4795 | |
| 4796 | // -- If reference is an lvalue reference and the initializer expression |
| 4797 | if (!isRValRef) { |
| 4798 | // -- is an lvalue (but is not a bit-field), and "cv1 T1" is |
| 4799 | // reference-compatible with "cv2 T2," or |
| 4800 | // |
| 4801 | // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. |
| 4802 | if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) { |
| 4803 | // C++ [over.ics.ref]p1: |
| 4804 | // When a parameter of reference type binds directly (8.5.3) |
| 4805 | // to an argument expression, the implicit conversion sequence |
| 4806 | // is the identity conversion, unless the argument expression |
| 4807 | // has a type that is a derived class of the parameter type, |
| 4808 | // in which case the implicit conversion sequence is a |
| 4809 | // derived-to-base Conversion (13.3.3.1). |
| 4810 | SetAsReferenceBinding(/*BindsDirectly=*/true); |
| 4811 | |
| 4812 | // Nothing more to do: the inaccessibility/ambiguity check for |
| 4813 | // derived-to-base conversions is suppressed when we're |
| 4814 | // computing the implicit conversion sequence (C++ |
| 4815 | // [over.best.ics]p2). |
| 4816 | return ICS; |
| 4817 | } |
| 4818 | |
| 4819 | // -- has a class type (i.e., T2 is a class type), where T1 is |
| 4820 | // not reference-related to T2, and can be implicitly |
| 4821 | // converted to an lvalue of type "cv3 T3," where "cv1 T1" |
| 4822 | // is reference-compatible with "cv3 T3" 92) (this |
| 4823 | // conversion is selected by enumerating the applicable |
| 4824 | // conversion functions (13.3.1.6) and choosing the best |
| 4825 | // one through overload resolution (13.3)), |
| 4826 | if (!SuppressUserConversions && T2->isRecordType() && |
| 4827 | S.isCompleteType(DeclLoc, T2) && |
| 4828 | RefRelationship == Sema::Ref_Incompatible) { |
| 4829 | if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, |
| 4830 | Init, T2, /*AllowRvalues=*/false, |
| 4831 | AllowExplicit)) |
| 4832 | return ICS; |
| 4833 | } |
| 4834 | } |
| 4835 | |
| 4836 | // -- Otherwise, the reference shall be an lvalue reference to a |
| 4837 | // non-volatile const type (i.e., cv1 shall be const), or the reference |
| 4838 | // shall be an rvalue reference. |
| 4839 | if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified())) { |
| 4840 | if (InitCategory.isRValue() && RefRelationship != Sema::Ref_Incompatible) |
| 4841 | ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType); |
| 4842 | return ICS; |
| 4843 | } |
| 4844 | |
| 4845 | // -- If the initializer expression |
| 4846 | // |
| 4847 | // -- is an xvalue, class prvalue, array prvalue or function |
| 4848 | // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or |
| 4849 | if (RefRelationship == Sema::Ref_Compatible && |
| 4850 | (InitCategory.isXValue() || |
| 4851 | (InitCategory.isPRValue() && |
| 4852 | (T2->isRecordType() || T2->isArrayType())) || |
| 4853 | (InitCategory.isLValue() && T2->isFunctionType()))) { |
| 4854 | // In C++11, this is always a direct binding. In C++98/03, it's a direct |
| 4855 | // binding unless we're binding to a class prvalue. |
| 4856 | // Note: Although xvalues wouldn't normally show up in C++98/03 code, we |
| 4857 | // allow the use of rvalue references in C++98/03 for the benefit of |
| 4858 | // standard library implementors; therefore, we need the xvalue check here. |
| 4859 | SetAsReferenceBinding(/*BindsDirectly=*/S.getLangOpts().CPlusPlus11 || |
| 4860 | !(InitCategory.isPRValue() || T2->isRecordType())); |
| 4861 | return ICS; |
| 4862 | } |
| 4863 | |
| 4864 | // -- has a class type (i.e., T2 is a class type), where T1 is not |
| 4865 | // reference-related to T2, and can be implicitly converted to |
| 4866 | // an xvalue, class prvalue, or function lvalue of type |
| 4867 | // "cv3 T3", where "cv1 T1" is reference-compatible with |
| 4868 | // "cv3 T3", |
| 4869 | // |
| 4870 | // then the reference is bound to the value of the initializer |
| 4871 | // expression in the first case and to the result of the conversion |
| 4872 | // in the second case (or, in either case, to an appropriate base |
| 4873 | // class subobject). |
| 4874 | if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && |
| 4875 | T2->isRecordType() && S.isCompleteType(DeclLoc, T2) && |
| 4876 | FindConversionForRefInit(S, ICS, DeclType, DeclLoc, |
| 4877 | Init, T2, /*AllowRvalues=*/true, |
| 4878 | AllowExplicit)) { |
| 4879 | // In the second case, if the reference is an rvalue reference |
| 4880 | // and the second standard conversion sequence of the |
| 4881 | // user-defined conversion sequence includes an lvalue-to-rvalue |
| 4882 | // conversion, the program is ill-formed. |
| 4883 | if (ICS.isUserDefined() && isRValRef && |
| 4884 | ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) |
| 4885 | ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); |
| 4886 | |
| 4887 | return ICS; |
| 4888 | } |
| 4889 | |
| 4890 | // A temporary of function type cannot be created; don't even try. |
| 4891 | if (T1->isFunctionType()) |
| 4892 | return ICS; |
| 4893 | |
| 4894 | // -- Otherwise, a temporary of type "cv1 T1" is created and |
| 4895 | // initialized from the initializer expression using the |
| 4896 | // rules for a non-reference copy initialization (8.5). The |
| 4897 | // reference is then bound to the temporary. If T1 is |
| 4898 | // reference-related to T2, cv1 must be the same |
| 4899 | // cv-qualification as, or greater cv-qualification than, |
| 4900 | // cv2; otherwise, the program is ill-formed. |
| 4901 | if (RefRelationship == Sema::Ref_Related) { |
| 4902 | // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then |
| 4903 | // we would be reference-compatible or reference-compatible with |
| 4904 | // added qualification. But that wasn't the case, so the reference |
| 4905 | // initialization fails. |
| 4906 | // |
| 4907 | // Note that we only want to check address spaces and cvr-qualifiers here. |
| 4908 | // ObjC GC, lifetime and unaligned qualifiers aren't important. |
| 4909 | Qualifiers T1Quals = T1.getQualifiers(); |
| 4910 | Qualifiers T2Quals = T2.getQualifiers(); |
| 4911 | T1Quals.removeObjCGCAttr(); |
| 4912 | T1Quals.removeObjCLifetime(); |
| 4913 | T2Quals.removeObjCGCAttr(); |
| 4914 | T2Quals.removeObjCLifetime(); |
| 4915 | // MS compiler ignores __unaligned qualifier for references; do the same. |
| 4916 | T1Quals.removeUnaligned(); |
| 4917 | T2Quals.removeUnaligned(); |
| 4918 | if (!T1Quals.compatiblyIncludes(T2Quals)) |
| 4919 | return ICS; |
| 4920 | } |
| 4921 | |
| 4922 | // If at least one of the types is a class type, the types are not |
| 4923 | // related, and we aren't allowed any user conversions, the |
| 4924 | // reference binding fails. This case is important for breaking |
| 4925 | // recursion, since TryImplicitConversion below will attempt to |
| 4926 | // create a temporary through the use of a copy constructor. |
| 4927 | if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && |
| 4928 | (T1->isRecordType() || T2->isRecordType())) |
| 4929 | return ICS; |
| 4930 | |
| 4931 | // If T1 is reference-related to T2 and the reference is an rvalue |
| 4932 | // reference, the initializer expression shall not be an lvalue. |
| 4933 | if (RefRelationship >= Sema::Ref_Related && isRValRef && |
| 4934 | Init->Classify(S.Context).isLValue()) { |
| 4935 | ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, Init, DeclType); |
| 4936 | return ICS; |
| 4937 | } |
| 4938 | |
| 4939 | // C++ [over.ics.ref]p2: |
| 4940 | // When a parameter of reference type is not bound directly to |
| 4941 | // an argument expression, the conversion sequence is the one |
| 4942 | // required to convert the argument expression to the |
| 4943 | // underlying type of the reference according to |
| 4944 | // 13.3.3.1. Conceptually, this conversion sequence corresponds |
| 4945 | // to copy-initializing a temporary of the underlying type with |
| 4946 | // the argument expression. Any difference in top-level |
| 4947 | // cv-qualification is subsumed by the initialization itself |
| 4948 | // and does not constitute a conversion. |
| 4949 | ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, |
| 4950 | AllowedExplicit::None, |
| 4951 | /*InOverloadResolution=*/false, |
| 4952 | /*CStyle=*/false, |
| 4953 | /*AllowObjCWritebackConversion=*/false, |
| 4954 | /*AllowObjCConversionOnExplicit=*/false); |
| 4955 | |
| 4956 | // Of course, that's still a reference binding. |
| 4957 | if (ICS.isStandard()) { |
| 4958 | ICS.Standard.ReferenceBinding = true; |
| 4959 | ICS.Standard.IsLvalueReference = !isRValRef; |
| 4960 | ICS.Standard.BindsToFunctionLvalue = false; |
| 4961 | ICS.Standard.BindsToRvalue = true; |
| 4962 | ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; |
| 4963 | ICS.Standard.ObjCLifetimeConversionBinding = false; |
| 4964 | } else if (ICS.isUserDefined()) { |
| 4965 | const ReferenceType *LValRefType = |
| 4966 | ICS.UserDefined.ConversionFunction->getReturnType() |
| 4967 | ->getAs<LValueReferenceType>(); |
| 4968 | |
| 4969 | // C++ [over.ics.ref]p3: |
| 4970 | // Except for an implicit object parameter, for which see 13.3.1, a |
| 4971 | // standard conversion sequence cannot be formed if it requires [...] |
| 4972 | // binding an rvalue reference to an lvalue other than a function |
| 4973 | // lvalue. |
| 4974 | // Note that the function case is not possible here. |
| 4975 | if (isRValRef && LValRefType) { |
| 4976 | ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); |
| 4977 | return ICS; |
| 4978 | } |
| 4979 | |
| 4980 | ICS.UserDefined.After.ReferenceBinding = true; |
| 4981 | ICS.UserDefined.After.IsLvalueReference = !isRValRef; |
| 4982 | ICS.UserDefined.After.BindsToFunctionLvalue = false; |
| 4983 | ICS.UserDefined.After.BindsToRvalue = !LValRefType; |
| 4984 | ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false; |
| 4985 | ICS.UserDefined.After.ObjCLifetimeConversionBinding = false; |
| 4986 | } |
| 4987 | |
| 4988 | return ICS; |
| 4989 | } |
| 4990 | |
| 4991 | static ImplicitConversionSequence |
| 4992 | TryCopyInitialization(Sema &S, Expr *From, QualType ToType, |
| 4993 | bool SuppressUserConversions, |
| 4994 | bool InOverloadResolution, |
| 4995 | bool AllowObjCWritebackConversion, |
| 4996 | bool AllowExplicit = false); |
| 4997 | |
| 4998 | /// TryListConversion - Try to copy-initialize a value of type ToType from the |
| 4999 | /// initializer list From. |
| 5000 | static ImplicitConversionSequence |
| 5001 | TryListConversion(Sema &S, InitListExpr *From, QualType ToType, |
| 5002 | bool SuppressUserConversions, |
| 5003 | bool InOverloadResolution, |
| 5004 | bool AllowObjCWritebackConversion) { |
| 5005 | // C++11 [over.ics.list]p1: |
| 5006 | // When an argument is an initializer list, it is not an expression and |
| 5007 | // special rules apply for converting it to a parameter type. |
| 5008 | |
| 5009 | ImplicitConversionSequence Result; |
| 5010 | Result.setBad(BadConversionSequence::no_conversion, From, ToType); |
| 5011 | |
| 5012 | // We need a complete type for what follows. Incomplete types can never be |
| 5013 | // initialized from init lists. |
| 5014 | if (!S.isCompleteType(From->getBeginLoc(), ToType)) |
| 5015 | return Result; |
| 5016 | |
| 5017 | // Per DR1467: |
| 5018 | // If the parameter type is a class X and the initializer list has a single |
| 5019 | // element of type cv U, where U is X or a class derived from X, the |
| 5020 | // implicit conversion sequence is the one required to convert the element |
| 5021 | // to the parameter type. |
| 5022 | // |
| 5023 | // Otherwise, if the parameter type is a character array [... ] |
| 5024 | // and the initializer list has a single element that is an |
| 5025 | // appropriately-typed string literal (8.5.2 [dcl.init.string]), the |
| 5026 | // implicit conversion sequence is the identity conversion. |
| 5027 | if (From->getNumInits() == 1) { |
| 5028 | if (ToType->isRecordType()) { |
| 5029 | QualType InitType = From->getInit(0)->getType(); |
| 5030 | if (S.Context.hasSameUnqualifiedType(InitType, ToType) || |
| 5031 | S.IsDerivedFrom(From->getBeginLoc(), InitType, ToType)) |
| 5032 | return TryCopyInitialization(S, From->getInit(0), ToType, |
| 5033 | SuppressUserConversions, |
| 5034 | InOverloadResolution, |
| 5035 | AllowObjCWritebackConversion); |
| 5036 | } |
| 5037 | |
| 5038 | if (const auto *AT = S.Context.getAsArrayType(ToType)) { |
| 5039 | if (S.IsStringInit(From->getInit(0), AT)) { |
| 5040 | InitializedEntity Entity = |
| 5041 | InitializedEntity::InitializeParameter(S.Context, ToType, |
| 5042 | /*Consumed=*/false); |
| 5043 | if (S.CanPerformCopyInitialization(Entity, From)) { |
| 5044 | Result.setStandard(); |
| 5045 | Result.Standard.setAsIdentityConversion(); |
| 5046 | Result.Standard.setFromType(ToType); |
| 5047 | Result.Standard.setAllToTypes(ToType); |
| 5048 | return Result; |
| 5049 | } |
| 5050 | } |
| 5051 | } |
| 5052 | } |
| 5053 | |
| 5054 | // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below). |
| 5055 | // C++11 [over.ics.list]p2: |
| 5056 | // If the parameter type is std::initializer_list<X> or "array of X" and |
| 5057 | // all the elements can be implicitly converted to X, the implicit |
| 5058 | // conversion sequence is the worst conversion necessary to convert an |
| 5059 | // element of the list to X. |
| 5060 | // |
| 5061 | // C++14 [over.ics.list]p3: |
| 5062 | // Otherwise, if the parameter type is "array of N X", if the initializer |
| 5063 | // list has exactly N elements or if it has fewer than N elements and X is |
| 5064 | // default-constructible, and if all the elements of the initializer list |
| 5065 | // can be implicitly converted to X, the implicit conversion sequence is |
| 5066 | // the worst conversion necessary to convert an element of the list to X. |
| 5067 | // |
| 5068 | // FIXME: We're missing a lot of these checks. |
| 5069 | bool toStdInitializerList = false; |
| 5070 | QualType X; |
| 5071 | if (ToType->isArrayType()) |
| 5072 | X = S.Context.getAsArrayType(ToType)->getElementType(); |
| 5073 | else |
| 5074 | toStdInitializerList = S.isStdInitializerList(ToType, &X); |
| 5075 | if (!X.isNull()) { |
| 5076 | for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) { |
| 5077 | Expr *Init = From->getInit(i); |
| 5078 | ImplicitConversionSequence ICS = |
| 5079 | TryCopyInitialization(S, Init, X, SuppressUserConversions, |
| 5080 | InOverloadResolution, |
| 5081 | AllowObjCWritebackConversion); |
| 5082 | // If a single element isn't convertible, fail. |
| 5083 | if (ICS.isBad()) { |
| 5084 | Result = ICS; |
| 5085 | break; |
| 5086 | } |
| 5087 | // Otherwise, look for the worst conversion. |
| 5088 | if (Result.isBad() || CompareImplicitConversionSequences( |
| 5089 | S, From->getBeginLoc(), ICS, Result) == |
| 5090 | ImplicitConversionSequence::Worse) |
| 5091 | Result = ICS; |
| 5092 | } |
| 5093 | |
| 5094 | // For an empty list, we won't have computed any conversion sequence. |
| 5095 | // Introduce the identity conversion sequence. |
| 5096 | if (From->getNumInits() == 0) { |
| 5097 | Result.setStandard(); |
| 5098 | Result.Standard.setAsIdentityConversion(); |
| 5099 | Result.Standard.setFromType(ToType); |
| 5100 | Result.Standard.setAllToTypes(ToType); |
| 5101 | } |
| 5102 | |
| 5103 | Result.setStdInitializerListElement(toStdInitializerList); |
| 5104 | return Result; |
| 5105 | } |
| 5106 | |
| 5107 | // C++14 [over.ics.list]p4: |
| 5108 | // C++11 [over.ics.list]p3: |
| 5109 | // Otherwise, if the parameter is a non-aggregate class X and overload |
| 5110 | // resolution chooses a single best constructor [...] the implicit |
| 5111 | // conversion sequence is a user-defined conversion sequence. If multiple |
| 5112 | // constructors are viable but none is better than the others, the |
| 5113 | // implicit conversion sequence is a user-defined conversion sequence. |
| 5114 | if (ToType->isRecordType() && !ToType->isAggregateType()) { |
| 5115 | // This function can deal with initializer lists. |
| 5116 | return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, |
| 5117 | AllowedExplicit::None, |
| 5118 | InOverloadResolution, /*CStyle=*/false, |
| 5119 | AllowObjCWritebackConversion, |
| 5120 | /*AllowObjCConversionOnExplicit=*/false); |
| 5121 | } |
| 5122 | |
| 5123 | // C++14 [over.ics.list]p5: |
| 5124 | // C++11 [over.ics.list]p4: |
| 5125 | // Otherwise, if the parameter has an aggregate type which can be |
| 5126 | // initialized from the initializer list [...] the implicit conversion |
| 5127 | // sequence is a user-defined conversion sequence. |
| 5128 | if (ToType->isAggregateType()) { |
| 5129 | // Type is an aggregate, argument is an init list. At this point it comes |
| 5130 | // down to checking whether the initialization works. |
| 5131 | // FIXME: Find out whether this parameter is consumed or not. |
| 5132 | InitializedEntity Entity = |
| 5133 | InitializedEntity::InitializeParameter(S.Context, ToType, |
| 5134 | /*Consumed=*/false); |
| 5135 | if (S.CanPerformAggregateInitializationForOverloadResolution(Entity, |
| 5136 | From)) { |
| 5137 | Result.setUserDefined(); |
| 5138 | Result.UserDefined.Before.setAsIdentityConversion(); |
| 5139 | // Initializer lists don't have a type. |
| 5140 | Result.UserDefined.Before.setFromType(QualType()); |
| 5141 | Result.UserDefined.Before.setAllToTypes(QualType()); |
| 5142 | |
| 5143 | Result.UserDefined.After.setAsIdentityConversion(); |
| 5144 | Result.UserDefined.After.setFromType(ToType); |
| 5145 | Result.UserDefined.After.setAllToTypes(ToType); |
| 5146 | Result.UserDefined.ConversionFunction = nullptr; |
| 5147 | } |
| 5148 | return Result; |
| 5149 | } |
| 5150 | |
| 5151 | // C++14 [over.ics.list]p6: |
| 5152 | // C++11 [over.ics.list]p5: |
| 5153 | // Otherwise, if the parameter is a reference, see 13.3.3.1.4. |
| 5154 | if (ToType->isReferenceType()) { |
| 5155 | // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't |
| 5156 | // mention initializer lists in any way. So we go by what list- |
| 5157 | // initialization would do and try to extrapolate from that. |
| 5158 | |
| 5159 | QualType T1 = ToType->castAs<ReferenceType>()->getPointeeType(); |
| 5160 | |
| 5161 | // If the initializer list has a single element that is reference-related |
| 5162 | // to the parameter type, we initialize the reference from that. |
| 5163 | if (From->getNumInits() == 1) { |
| 5164 | Expr *Init = From->getInit(0); |
| 5165 | |
| 5166 | QualType T2 = Init->getType(); |
| 5167 | |
| 5168 | // If the initializer is the address of an overloaded function, try |
| 5169 | // to resolve the overloaded function. If all goes well, T2 is the |
| 5170 | // type of the resulting function. |
| 5171 | if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { |
| 5172 | DeclAccessPair Found; |
| 5173 | if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction( |
| 5174 | Init, ToType, false, Found)) |
| 5175 | T2 = Fn->getType(); |
| 5176 | } |
| 5177 | |
| 5178 | // Compute some basic properties of the types and the initializer. |
| 5179 | Sema::ReferenceCompareResult RefRelationship = |
| 5180 | S.CompareReferenceRelationship(From->getBeginLoc(), T1, T2); |
| 5181 | |
| 5182 | if (RefRelationship >= Sema::Ref_Related) { |
| 5183 | return TryReferenceInit(S, Init, ToType, /*FIXME*/ From->getBeginLoc(), |
| 5184 | SuppressUserConversions, |
| 5185 | /*AllowExplicit=*/false); |
| 5186 | } |
| 5187 | } |
| 5188 | |
| 5189 | // Otherwise, we bind the reference to a temporary created from the |
| 5190 | // initializer list. |
| 5191 | Result = TryListConversion(S, From, T1, SuppressUserConversions, |
| 5192 | InOverloadResolution, |
| 5193 | AllowObjCWritebackConversion); |
| 5194 | if (Result.isFailure()) |
| 5195 | return Result; |
| 5196 | assert(!Result.isEllipsis() &&((void)0) |
| 5197 | "Sub-initialization cannot result in ellipsis conversion.")((void)0); |
| 5198 | |
| 5199 | // Can we even bind to a temporary? |
| 5200 | if (ToType->isRValueReferenceType() || |
| 5201 | (T1.isConstQualified() && !T1.isVolatileQualified())) { |
| 5202 | StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard : |
| 5203 | Result.UserDefined.After; |
| 5204 | SCS.ReferenceBinding = true; |
| 5205 | SCS.IsLvalueReference = ToType->isLValueReferenceType(); |
| 5206 | SCS.BindsToRvalue = true; |
| 5207 | SCS.BindsToFunctionLvalue = false; |
| 5208 | SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false; |
| 5209 | SCS.ObjCLifetimeConversionBinding = false; |
| 5210 | } else |
| 5211 | Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue, |
| 5212 | From, ToType); |
| 5213 | return Result; |
| 5214 | } |
| 5215 | |
| 5216 | // C++14 [over.ics.list]p7: |
| 5217 | // C++11 [over.ics.list]p6: |
| 5218 | // Otherwise, if the parameter type is not a class: |
| 5219 | if (!ToType->isRecordType()) { |
| 5220 | // - if the initializer list has one element that is not itself an |
| 5221 | // initializer list, the implicit conversion sequence is the one |
| 5222 | // required to convert the element to the parameter type. |
| 5223 | unsigned NumInits = From->getNumInits(); |
| 5224 | if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0))) |
| 5225 | Result = TryCopyInitialization(S, From->getInit(0), ToType, |
| 5226 | SuppressUserConversions, |
| 5227 | InOverloadResolution, |
| 5228 | AllowObjCWritebackConversion); |
| 5229 | // - if the initializer list has no elements, the implicit conversion |
| 5230 | // sequence is the identity conversion. |
| 5231 | else if (NumInits == 0) { |
| 5232 | Result.setStandard(); |
| 5233 | Result.Standard.setAsIdentityConversion(); |
| 5234 | Result.Standard.setFromType(ToType); |
| 5235 | Result.Standard.setAllToTypes(ToType); |
| 5236 | } |
| 5237 | return Result; |
| 5238 | } |
| 5239 | |
| 5240 | // C++14 [over.ics.list]p8: |
| 5241 | // C++11 [over.ics.list]p7: |
| 5242 | // In all cases other than those enumerated above, no conversion is possible |
| 5243 | return Result; |
| 5244 | } |
| 5245 | |
| 5246 | /// TryCopyInitialization - Try to copy-initialize a value of type |
| 5247 | /// ToType from the expression From. Return the implicit conversion |
| 5248 | /// sequence required to pass this argument, which may be a bad |
| 5249 | /// conversion sequence (meaning that the argument cannot be passed to |
| 5250 | /// a parameter of this type). If @p SuppressUserConversions, then we |
| 5251 | /// do not permit any user-defined conversion sequences. |
| 5252 | static ImplicitConversionSequence |
| 5253 | TryCopyInitialization(Sema &S, Expr *From, QualType ToType, |
| 5254 | bool SuppressUserConversions, |
| 5255 | bool InOverloadResolution, |
| 5256 | bool AllowObjCWritebackConversion, |
| 5257 | bool AllowExplicit) { |
| 5258 | if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From)) |
| 5259 | return TryListConversion(S, FromInitList, ToType, SuppressUserConversions, |
| 5260 | InOverloadResolution,AllowObjCWritebackConversion); |
| 5261 | |
| 5262 | if (ToType->isReferenceType()) |
| 5263 | return TryReferenceInit(S, From, ToType, |
| 5264 | /*FIXME:*/ From->getBeginLoc(), |
| 5265 | SuppressUserConversions, AllowExplicit); |
| 5266 | |
| 5267 | return TryImplicitConversion(S, From, ToType, |
| 5268 | SuppressUserConversions, |
| 5269 | AllowedExplicit::None, |
| 5270 | InOverloadResolution, |
| 5271 | /*CStyle=*/false, |
| 5272 | AllowObjCWritebackConversion, |
| 5273 | /*AllowObjCConversionOnExplicit=*/false); |
| 5274 | } |
| 5275 | |
| 5276 | static bool TryCopyInitialization(const CanQualType FromQTy, |
| 5277 | const CanQualType ToQTy, |
| 5278 | Sema &S, |
| 5279 | SourceLocation Loc, |
| 5280 | ExprValueKind FromVK) { |
| 5281 | OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK); |
| 5282 | ImplicitConversionSequence ICS = |
| 5283 | TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false); |
| 5284 | |
| 5285 | return !ICS.isBad(); |
| 5286 | } |
| 5287 | |
| 5288 | /// TryObjectArgumentInitialization - Try to initialize the object |
| 5289 | /// parameter of the given member function (@c Method) from the |
| 5290 | /// expression @p From. |
| 5291 | static ImplicitConversionSequence |
| 5292 | TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType, |
| 5293 | Expr::Classification FromClassification, |
| 5294 | CXXMethodDecl *Method, |
| 5295 | CXXRecordDecl *ActingContext) { |
| 5296 | QualType ClassType = S.Context.getTypeDeclType(ActingContext); |
| 5297 | // [class.dtor]p2: A destructor can be invoked for a const, volatile or |
| 5298 | // const volatile object. |
| 5299 | Qualifiers Quals = Method->getMethodQualifiers(); |
| 5300 | if (isa<CXXDestructorDecl>(Method)) { |
| 5301 | Quals.addConst(); |
| 5302 | Quals.addVolatile(); |
| 5303 | } |
| 5304 | |
| 5305 | QualType ImplicitParamType = S.Context.getQualifiedType(ClassType, Quals); |
| 5306 | |
| 5307 | // Set up the conversion sequence as a "bad" conversion, to allow us |
| 5308 | // to exit early. |
| 5309 | ImplicitConversionSequence ICS; |
| 5310 | |
| 5311 | // We need to have an object of class type. |
| 5312 | if (const PointerType *PT = FromType->getAs<PointerType>()) { |
| 5313 | FromType = PT->getPointeeType(); |
| 5314 | |
| 5315 | // When we had a pointer, it's implicitly dereferenced, so we |
| 5316 | // better have an lvalue. |
| 5317 | assert(FromClassification.isLValue())((void)0); |
| 5318 | } |
| 5319 | |
| 5320 | assert(FromType->isRecordType())((void)0); |
| 5321 | |
| 5322 | // C++0x [over.match.funcs]p4: |
| 5323 | // For non-static member functions, the type of the implicit object |
| 5324 | // parameter is |
| 5325 | // |
| 5326 | // - "lvalue reference to cv X" for functions declared without a |
| 5327 | // ref-qualifier or with the & ref-qualifier |
| 5328 | // - "rvalue reference to cv X" for functions declared with the && |
| 5329 | // ref-qualifier |
| 5330 | // |
| 5331 | // where X is the class of which the function is a member and cv is the |
| 5332 | // cv-qualification on the member function declaration. |
| 5333 | // |
| 5334 | // However, when finding an implicit conversion sequence for the argument, we |
| 5335 | // are not allowed to perform user-defined conversions |
| 5336 | // (C++ [over.match.funcs]p5). We perform a simplified version of |
| 5337 | // reference binding here, that allows class rvalues to bind to |
| 5338 | // non-constant references. |
| 5339 | |
| 5340 | // First check the qualifiers. |
| 5341 | QualType FromTypeCanon = S.Context.getCanonicalType(FromType); |
| 5342 | if (ImplicitParamType.getCVRQualifiers() |
| 5343 | != FromTypeCanon.getLocalCVRQualifiers() && |
| 5344 | !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { |
| 5345 | ICS.setBad(BadConversionSequence::bad_qualifiers, |
| 5346 | FromType, ImplicitParamType); |
| 5347 | return ICS; |
| 5348 | } |
| 5349 | |
| 5350 | if (FromTypeCanon.hasAddressSpace()) { |
| 5351 | Qualifiers QualsImplicitParamType = ImplicitParamType.getQualifiers(); |
| 5352 | Qualifiers QualsFromType = FromTypeCanon.getQualifiers(); |
| 5353 | if (!QualsImplicitParamType.isAddressSpaceSupersetOf(QualsFromType)) { |
| 5354 | ICS.setBad(BadConversionSequence::bad_qualifiers, |
| 5355 | FromType, ImplicitParamType); |
| 5356 | return ICS; |
| 5357 | } |
| 5358 | } |
| 5359 | |
| 5360 | // Check that we have either the same type or a derived type. It |
| 5361 | // affects the conversion rank. |
| 5362 | QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); |
| 5363 | ImplicitConversionKind SecondKind; |
| 5364 | if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { |
| 5365 | SecondKind = ICK_Identity; |
| 5366 | } else if (S.IsDerivedFrom(Loc, FromType, ClassType)) |
| 5367 | SecondKind = ICK_Derived_To_Base; |
| 5368 | else { |
| 5369 | ICS.setBad(BadConversionSequence::unrelated_class, |
| 5370 | FromType, ImplicitParamType); |
| 5371 | return ICS; |
| 5372 | } |
| 5373 | |
| 5374 | // Check the ref-qualifier. |
| 5375 | switch (Method->getRefQualifier()) { |
| 5376 | case RQ_None: |
| 5377 | // Do nothing; we don't care about lvalueness or rvalueness. |
| 5378 | break; |
| 5379 | |
| 5380 | case RQ_LValue: |
| 5381 | if (!FromClassification.isLValue() && !Quals.hasOnlyConst()) { |
| 5382 | // non-const lvalue reference cannot bind to an rvalue |
| 5383 | ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, |
| 5384 | ImplicitParamType); |
| 5385 | return ICS; |
| 5386 | } |
| 5387 | break; |
| 5388 | |
| 5389 | case RQ_RValue: |
| 5390 | if (!FromClassification.isRValue()) { |
| 5391 | // rvalue reference cannot bind to an lvalue |
| 5392 | ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, |
| 5393 | ImplicitParamType); |
| 5394 | return ICS; |
| 5395 | } |
| 5396 | break; |
| 5397 | } |
| 5398 | |
| 5399 | // Success. Mark this as a reference binding. |
| 5400 | ICS.setStandard(); |
| 5401 | ICS.Standard.setAsIdentityConversion(); |
| 5402 | ICS.Standard.Second = SecondKind; |
| 5403 | ICS.Standard.setFromType(FromType); |
| 5404 | ICS.Standard.setAllToTypes(ImplicitParamType); |
| 5405 | ICS.Standard.ReferenceBinding = true; |
| 5406 | ICS.Standard.DirectBinding = true; |
| 5407 | ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; |
| 5408 | ICS.Standard.BindsToFunctionLvalue = false; |
| 5409 | ICS.Standard.BindsToRvalue = FromClassification.isRValue(); |
| 5410 | ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier |
| 5411 | = (Method->getRefQualifier() == RQ_None); |
| 5412 | return ICS; |
| 5413 | } |
| 5414 | |
| 5415 | /// PerformObjectArgumentInitialization - Perform initialization of |
| 5416 | /// the implicit object parameter for the given Method with the given |
| 5417 | /// expression. |
| 5418 | ExprResult |
| 5419 | Sema::PerformObjectArgumentInitialization(Expr *From, |
| 5420 | NestedNameSpecifier *Qualifier, |
| 5421 | NamedDecl *FoundDecl, |
| 5422 | CXXMethodDecl *Method) { |
| 5423 | QualType FromRecordType, DestType; |
| 5424 | QualType ImplicitParamRecordType = |
| 5425 | Method->getThisType()->castAs<PointerType>()->getPointeeType(); |
| 5426 | |
| 5427 | Expr::Classification FromClassification; |
| 5428 | if (const PointerType *PT = From->getType()->getAs<PointerType>()) { |
| 5429 | FromRecordType = PT->getPointeeType(); |
| 5430 | DestType = Method->getThisType(); |
| 5431 | FromClassification = Expr::Classification::makeSimpleLValue(); |
| 5432 | } else { |
| 5433 | FromRecordType = From->getType(); |
| 5434 | DestType = ImplicitParamRecordType; |
| 5435 | FromClassification = From->Classify(Context); |
| 5436 | |
| 5437 | // When performing member access on a prvalue, materialize a temporary. |
| 5438 | if (From->isPRValue()) { |
| 5439 | From = CreateMaterializeTemporaryExpr(FromRecordType, From, |
| 5440 | Method->getRefQualifier() != |
| 5441 | RefQualifierKind::RQ_RValue); |
| 5442 | } |
| 5443 | } |
| 5444 | |
| 5445 | // Note that we always use the true parent context when performing |
| 5446 | // the actual argument initialization. |
| 5447 | ImplicitConversionSequence ICS = TryObjectArgumentInitialization( |
| 5448 | *this, From->getBeginLoc(), From->getType(), FromClassification, Method, |
| 5449 | Method->getParent()); |
| 5450 | if (ICS.isBad()) { |
| 5451 | switch (ICS.Bad.Kind) { |
| 5452 | case BadConversionSequence::bad_qualifiers: { |
| 5453 | Qualifiers FromQs = FromRecordType.getQualifiers(); |
| 5454 | Qualifiers ToQs = DestType.getQualifiers(); |
| 5455 | unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); |
| 5456 | if (CVR) { |
| 5457 | Diag(From->getBeginLoc(), diag::err_member_function_call_bad_cvr) |
| 5458 | << Method->getDeclName() << FromRecordType << (CVR - 1) |
| 5459 | << From->getSourceRange(); |
| 5460 | Diag(Method->getLocation(), diag::note_previous_decl) |
| 5461 | << Method->getDeclName(); |
| 5462 | return ExprError(); |
| 5463 | } |
| 5464 | break; |
| 5465 | } |
| 5466 | |
| 5467 | case BadConversionSequence::lvalue_ref_to_rvalue: |
| 5468 | case BadConversionSequence::rvalue_ref_to_lvalue: { |
| 5469 | bool IsRValueQualified = |
| 5470 | Method->getRefQualifier() == RefQualifierKind::RQ_RValue; |
| 5471 | Diag(From->getBeginLoc(), diag::err_member_function_call_bad_ref) |
| 5472 | << Method->getDeclName() << FromClassification.isRValue() |
| 5473 | << IsRValueQualified; |
| 5474 | Diag(Method->getLocation(), diag::note_previous_decl) |
| 5475 | << Method->getDeclName(); |
| 5476 | return ExprError(); |
| 5477 | } |
| 5478 | |
| 5479 | case BadConversionSequence::no_conversion: |
| 5480 | case BadConversionSequence::unrelated_class: |
| 5481 | break; |
| 5482 | } |
| 5483 | |
| 5484 | return Diag(From->getBeginLoc(), diag::err_member_function_call_bad_type) |
| 5485 | << ImplicitParamRecordType << FromRecordType |
| 5486 | << From->getSourceRange(); |
| 5487 | } |
| 5488 | |
| 5489 | if (ICS.Standard.Second == ICK_Derived_To_Base) { |
| 5490 | ExprResult FromRes = |
| 5491 | PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); |
| 5492 | if (FromRes.isInvalid()) |
| 5493 | return ExprError(); |
| 5494 | From = FromRes.get(); |
| 5495 | } |
| 5496 | |
| 5497 | if (!Context.hasSameType(From->getType(), DestType)) { |
| 5498 | CastKind CK; |
| 5499 | QualType PteeTy = DestType->getPointeeType(); |
| 5500 | LangAS DestAS = |
| 5501 | PteeTy.isNull() ? DestType.getAddressSpace() : PteeTy.getAddressSpace(); |
| 5502 | if (FromRecordType.getAddressSpace() != DestAS) |
| 5503 | CK = CK_AddressSpaceConversion; |
| 5504 | else |
| 5505 | CK = CK_NoOp; |
| 5506 | From = ImpCastExprToType(From, DestType, CK, From->getValueKind()).get(); |
| 5507 | } |
| 5508 | return From; |
| 5509 | } |
| 5510 | |
| 5511 | /// TryContextuallyConvertToBool - Attempt to contextually convert the |
| 5512 | /// expression From to bool (C++0x [conv]p3). |
| 5513 | static ImplicitConversionSequence |
| 5514 | TryContextuallyConvertToBool(Sema &S, Expr *From) { |
| 5515 | // C++ [dcl.init]/17.8: |
| 5516 | // - Otherwise, if the initialization is direct-initialization, the source |
| 5517 | // type is std::nullptr_t, and the destination type is bool, the initial |
| 5518 | // value of the object being initialized is false. |
| 5519 | if (From->getType()->isNullPtrType()) |
| 5520 | return ImplicitConversionSequence::getNullptrToBool(From->getType(), |
| 5521 | S.Context.BoolTy, |
| 5522 | From->isGLValue()); |
| 5523 | |
| 5524 | // All other direct-initialization of bool is equivalent to an implicit |
| 5525 | // conversion to bool in which explicit conversions are permitted. |
| 5526 | return TryImplicitConversion(S, From, S.Context.BoolTy, |
| 5527 | /*SuppressUserConversions=*/false, |
| 5528 | AllowedExplicit::Conversions, |
| 5529 | /*InOverloadResolution=*/false, |
| 5530 | /*CStyle=*/false, |
| 5531 | /*AllowObjCWritebackConversion=*/false, |
| 5532 | /*AllowObjCConversionOnExplicit=*/false); |
| 5533 | } |
| 5534 | |
| 5535 | /// PerformContextuallyConvertToBool - Perform a contextual conversion |
| 5536 | /// of the expression From to bool (C++0x [conv]p3). |
| 5537 | ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { |
| 5538 | if (checkPlaceholderForOverload(*this, From)) |
| 5539 | return ExprError(); |
| 5540 | |
| 5541 | ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); |
| 5542 | if (!ICS.isBad()) |
| 5543 | return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); |
| 5544 | |
| 5545 | if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) |
| 5546 | return Diag(From->getBeginLoc(), diag::err_typecheck_bool_condition) |
| 5547 | << From->getType() << From->getSourceRange(); |
| 5548 | return ExprError(); |
| 5549 | } |
| 5550 | |
| 5551 | /// Check that the specified conversion is permitted in a converted constant |
| 5552 | /// expression, according to C++11 [expr.const]p3. Return true if the conversion |
| 5553 | /// is acceptable. |
| 5554 | static bool CheckConvertedConstantConversions(Sema &S, |
| 5555 | StandardConversionSequence &SCS) { |
| 5556 | // Since we know that the target type is an integral or unscoped enumeration |
| 5557 | // type, most conversion kinds are impossible. All possible First and Third |
| 5558 | // conversions are fine. |
| 5559 | switch (SCS.Second) { |
| 5560 | case ICK_Identity: |
| 5561 | case ICK_Integral_Promotion: |
| 5562 | case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere. |
| 5563 | case ICK_Zero_Queue_Conversion: |
| 5564 | return true; |
| 5565 | |
| 5566 | case ICK_Boolean_Conversion: |
| 5567 | // Conversion from an integral or unscoped enumeration type to bool is |
| 5568 | // classified as ICK_Boolean_Conversion, but it's also arguably an integral |
| 5569 | // conversion, so we allow it in a converted constant expression. |
| 5570 | // |
| 5571 | // FIXME: Per core issue 1407, we should not allow this, but that breaks |
| 5572 | // a lot of popular code. We should at least add a warning for this |
| 5573 | // (non-conforming) extension. |
| 5574 | return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() && |
| 5575 | SCS.getToType(2)->isBooleanType(); |
| 5576 | |
| 5577 | case ICK_Pointer_Conversion: |
| 5578 | case ICK_Pointer_Member: |
| 5579 | // C++1z: null pointer conversions and null member pointer conversions are |
| 5580 | // only permitted if the source type is std::nullptr_t. |
| 5581 | return SCS.getFromType()->isNullPtrType(); |
| 5582 | |
| 5583 | case ICK_Floating_Promotion: |
| 5584 | case ICK_Complex_Promotion: |
| 5585 | case ICK_Floating_Conversion: |
| 5586 | case ICK_Complex_Conversion: |
| 5587 | case ICK_Floating_Integral: |
| 5588 | case ICK_Compatible_Conversion: |
| 5589 | case ICK_Derived_To_Base: |
| 5590 | case ICK_Vector_Conversion: |
| 5591 | case ICK_SVE_Vector_Conversion: |
| 5592 | case ICK_Vector_Splat: |
| 5593 | case ICK_Complex_Real: |
| 5594 | case ICK_Block_Pointer_Conversion: |
| 5595 | case ICK_TransparentUnionConversion: |
| 5596 | case ICK_Writeback_Conversion: |
| 5597 | case ICK_Zero_Event_Conversion: |
| 5598 | case ICK_C_Only_Conversion: |
| 5599 | case ICK_Incompatible_Pointer_Conversion: |
| 5600 | return false; |
| 5601 | |
| 5602 | case ICK_Lvalue_To_Rvalue: |
| 5603 | case ICK_Array_To_Pointer: |
| 5604 | case ICK_Function_To_Pointer: |
| 5605 | llvm_unreachable("found a first conversion kind in Second")__builtin_unreachable(); |
| 5606 | |
| 5607 | case ICK_Function_Conversion: |
| 5608 | case ICK_Qualification: |
| 5609 | llvm_unreachable("found a third conversion kind in Second")__builtin_unreachable(); |
| 5610 | |
| 5611 | case ICK_Num_Conversion_Kinds: |
| 5612 | break; |
| 5613 | } |
| 5614 | |
| 5615 | llvm_unreachable("unknown conversion kind")__builtin_unreachable(); |
| 5616 | } |
| 5617 | |
| 5618 | /// CheckConvertedConstantExpression - Check that the expression From is a |
| 5619 | /// converted constant expression of type T, perform the conversion and produce |
| 5620 | /// the converted expression, per C++11 [expr.const]p3. |
| 5621 | static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From, |
| 5622 | QualType T, APValue &Value, |
| 5623 | Sema::CCEKind CCE, |
| 5624 | bool RequireInt, |
| 5625 | NamedDecl *Dest) { |
| 5626 | assert(S.getLangOpts().CPlusPlus11 &&((void)0) |
| 5627 | "converted constant expression outside C++11")((void)0); |
| 5628 | |
| 5629 | if (checkPlaceholderForOverload(S, From)) |
| 5630 | return ExprError(); |
| 5631 | |
| 5632 | // C++1z [expr.const]p3: |
| 5633 | // A converted constant expression of type T is an expression, |
| 5634 | // implicitly converted to type T, where the converted |
| 5635 | // expression is a constant expression and the implicit conversion |
| 5636 | // sequence contains only [... list of conversions ...]. |
| 5637 | ImplicitConversionSequence ICS = |
| 5638 | CCE == Sema::CCEK_ExplicitBool |
| 5639 | ? TryContextuallyConvertToBool(S, From) |
| 5640 | : TryCopyInitialization(S, From, T, |
| 5641 | /*SuppressUserConversions=*/false, |
| 5642 | /*InOverloadResolution=*/false, |
| 5643 | /*AllowObjCWritebackConversion=*/false, |
| 5644 | /*AllowExplicit=*/false); |
| 5645 | StandardConversionSequence *SCS = nullptr; |
| 5646 | switch (ICS.getKind()) { |
| 5647 | case ImplicitConversionSequence::StandardConversion: |
| 5648 | SCS = &ICS.Standard; |
| 5649 | break; |
| 5650 | case ImplicitConversionSequence::UserDefinedConversion: |
| 5651 | if (T->isRecordType()) |
| 5652 | SCS = &ICS.UserDefined.Before; |
| 5653 | else |
| 5654 | SCS = &ICS.UserDefined.After; |
| 5655 | break; |
| 5656 | case ImplicitConversionSequence::AmbiguousConversion: |
| 5657 | case ImplicitConversionSequence::BadConversion: |
| 5658 | if (!S.DiagnoseMultipleUserDefinedConversion(From, T)) |
| 5659 | return S.Diag(From->getBeginLoc(), |
| 5660 | diag::err_typecheck_converted_constant_expression) |
| 5661 | << From->getType() << From->getSourceRange() << T; |
| 5662 | return ExprError(); |
| 5663 | |
| 5664 | case ImplicitConversionSequence::EllipsisConversion: |
| 5665 | llvm_unreachable("ellipsis conversion in converted constant expression")__builtin_unreachable(); |
| 5666 | } |
| 5667 | |
| 5668 | // Check that we would only use permitted conversions. |
| 5669 | if (!CheckConvertedConstantConversions(S, *SCS)) { |
| 5670 | return S.Diag(From->getBeginLoc(), |
| 5671 | diag::err_typecheck_converted_constant_expression_disallowed) |
| 5672 | << From->getType() << From->getSourceRange() << T; |
| 5673 | } |
| 5674 | // [...] and where the reference binding (if any) binds directly. |
| 5675 | if (SCS->ReferenceBinding && !SCS->DirectBinding) { |
| 5676 | return S.Diag(From->getBeginLoc(), |
| 5677 | diag::err_typecheck_converted_constant_expression_indirect) |
| 5678 | << From->getType() << From->getSourceRange() << T; |
| 5679 | } |
| 5680 | |
| 5681 | // Usually we can simply apply the ImplicitConversionSequence we formed |
| 5682 | // earlier, but that's not guaranteed to work when initializing an object of |
| 5683 | // class type. |
| 5684 | ExprResult Result; |
| 5685 | if (T->isRecordType()) { |
| 5686 | assert(CCE == Sema::CCEK_TemplateArg &&((void)0) |
| 5687 | "unexpected class type converted constant expr")((void)0); |
| 5688 | Result = S.PerformCopyInitialization( |
| 5689 | InitializedEntity::InitializeTemplateParameter( |
| 5690 | T, cast<NonTypeTemplateParmDecl>(Dest)), |
| 5691 | SourceLocation(), From); |
| 5692 | } else { |
| 5693 | Result = S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting); |
| 5694 | } |
| 5695 | if (Result.isInvalid()) |
| 5696 | return Result; |
| 5697 | |
| 5698 | // C++2a [intro.execution]p5: |
| 5699 | // A full-expression is [...] a constant-expression [...] |
| 5700 | Result = |
| 5701 | S.ActOnFinishFullExpr(Result.get(), From->getExprLoc(), |
| 5702 | /*DiscardedValue=*/false, /*IsConstexpr=*/true); |
| 5703 | if (Result.isInvalid()) |
| 5704 | return Result; |
| 5705 | |
| 5706 | // Check for a narrowing implicit conversion. |
| 5707 | bool ReturnPreNarrowingValue = false; |
| 5708 | APValue PreNarrowingValue; |
| 5709 | QualType PreNarrowingType; |
| 5710 | switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue, |
| 5711 | PreNarrowingType)) { |
| 5712 | case NK_Dependent_Narrowing: |
| 5713 | // Implicit conversion to a narrower type, but the expression is |
| 5714 | // value-dependent so we can't tell whether it's actually narrowing. |
| 5715 | case NK_Variable_Narrowing: |
| 5716 | // Implicit conversion to a narrower type, and the value is not a constant |
| 5717 | // expression. We'll diagnose this in a moment. |
| 5718 | case NK_Not_Narrowing: |
| 5719 | break; |
| 5720 | |
| 5721 | case NK_Constant_Narrowing: |
| 5722 | if (CCE == Sema::CCEK_ArrayBound && |
| 5723 | PreNarrowingType->isIntegralOrEnumerationType() && |
| 5724 | PreNarrowingValue.isInt()) { |
| 5725 | // Don't diagnose array bound narrowing here; we produce more precise |
| 5726 | // errors by allowing the un-narrowed value through. |
| 5727 | ReturnPreNarrowingValue = true; |
| 5728 | break; |
| 5729 | } |
| 5730 | S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing) |
| 5731 | << CCE << /*Constant*/ 1 |
| 5732 | << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T; |
| 5733 | break; |
| 5734 | |
| 5735 | case NK_Type_Narrowing: |
| 5736 | // FIXME: It would be better to diagnose that the expression is not a |
| 5737 | // constant expression. |
| 5738 | S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing) |
| 5739 | << CCE << /*Constant*/ 0 << From->getType() << T; |
| 5740 | break; |
| 5741 | } |
| 5742 | |
| 5743 | if (Result.get()->isValueDependent()) { |
| 5744 | Value = APValue(); |
| 5745 | return Result; |
| 5746 | } |
| 5747 | |
| 5748 | // Check the expression is a constant expression. |
| 5749 | SmallVector<PartialDiagnosticAt, 8> Notes; |
| 5750 | Expr::EvalResult Eval; |
| 5751 | Eval.Diag = &Notes; |
| 5752 | |
| 5753 | ConstantExprKind Kind; |
| 5754 | if (CCE == Sema::CCEK_TemplateArg && T->isRecordType()) |
| 5755 | Kind = ConstantExprKind::ClassTemplateArgument; |
| 5756 | else if (CCE == Sema::CCEK_TemplateArg) |
| 5757 | Kind = ConstantExprKind::NonClassTemplateArgument; |
| 5758 | else |
| 5759 | Kind = ConstantExprKind::Normal; |
| 5760 | |
| 5761 | if (!Result.get()->EvaluateAsConstantExpr(Eval, S.Context, Kind) || |
| 5762 | (RequireInt && !Eval.Val.isInt())) { |
| 5763 | // The expression can't be folded, so we can't keep it at this position in |
| 5764 | // the AST. |
| 5765 | Result = ExprError(); |
| 5766 | } else { |
| 5767 | Value = Eval.Val; |
| 5768 | |
| 5769 | if (Notes.empty()) { |
| 5770 | // It's a constant expression. |
| 5771 | Expr *E = ConstantExpr::Create(S.Context, Result.get(), Value); |
| 5772 | if (ReturnPreNarrowingValue) |
| 5773 | Value = std::move(PreNarrowingValue); |
| 5774 | return E; |
| 5775 | } |
| 5776 | } |
| 5777 | |
| 5778 | // It's not a constant expression. Produce an appropriate diagnostic. |
| 5779 | if (Notes.size() == 1 && |
| 5780 | Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr) { |
| 5781 | S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE; |
| 5782 | } else if (!Notes.empty() && Notes[0].second.getDiagID() == |
| 5783 | diag::note_constexpr_invalid_template_arg) { |
| 5784 | Notes[0].second.setDiagID(diag::err_constexpr_invalid_template_arg); |
| 5785 | for (unsigned I = 0; I < Notes.size(); ++I) |
| 5786 | S.Diag(Notes[I].first, Notes[I].second); |
| 5787 | } else { |
| 5788 | S.Diag(From->getBeginLoc(), diag::err_expr_not_cce) |
| 5789 | << CCE << From->getSourceRange(); |
| 5790 | for (unsigned I = 0; I < Notes.size(); ++I) |
| 5791 | S.Diag(Notes[I].first, Notes[I].second); |
| 5792 | } |
| 5793 | return ExprError(); |
| 5794 | } |
| 5795 | |
| 5796 | ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T, |
| 5797 | APValue &Value, CCEKind CCE, |
| 5798 | NamedDecl *Dest) { |
| 5799 | return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false, |
| 5800 | Dest); |
| 5801 | } |
| 5802 | |
| 5803 | ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T, |
| 5804 | llvm::APSInt &Value, |
| 5805 | CCEKind CCE) { |
| 5806 | assert(T->isIntegralOrEnumerationType() && "unexpected converted const type")((void)0); |
| 5807 | |
| 5808 | APValue V; |
| 5809 | auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true, |
| 5810 | /*Dest=*/nullptr); |
| 5811 | if (!R.isInvalid() && !R.get()->isValueDependent()) |
| 5812 | Value = V.getInt(); |
| 5813 | return R; |
| 5814 | } |
| 5815 | |
| 5816 | |
| 5817 | /// dropPointerConversions - If the given standard conversion sequence |
| 5818 | /// involves any pointer conversions, remove them. This may change |
| 5819 | /// the result type of the conversion sequence. |
| 5820 | static void dropPointerConversion(StandardConversionSequence &SCS) { |
| 5821 | if (SCS.Second == ICK_Pointer_Conversion) { |
| 5822 | SCS.Second = ICK_Identity; |
| 5823 | SCS.Third = ICK_Identity; |
| 5824 | SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0]; |
| 5825 | } |
| 5826 | } |
| 5827 | |
| 5828 | /// TryContextuallyConvertToObjCPointer - Attempt to contextually |
| 5829 | /// convert the expression From to an Objective-C pointer type. |
| 5830 | static ImplicitConversionSequence |
| 5831 | TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) { |
| 5832 | // Do an implicit conversion to 'id'. |
| 5833 | QualType Ty = S.Context.getObjCIdType(); |
| 5834 | ImplicitConversionSequence ICS |
| 5835 | = TryImplicitConversion(S, From, Ty, |
| 5836 | // FIXME: Are these flags correct? |
| 5837 | /*SuppressUserConversions=*/false, |
| 5838 | AllowedExplicit::Conversions, |
| 5839 | /*InOverloadResolution=*/false, |
| 5840 | /*CStyle=*/false, |
| 5841 | /*AllowObjCWritebackConversion=*/false, |
| 5842 | /*AllowObjCConversionOnExplicit=*/true); |
| 5843 | |
| 5844 | // Strip off any final conversions to 'id'. |
| 5845 | switch (ICS.getKind()) { |
| 5846 | case ImplicitConversionSequence::BadConversion: |
| 5847 | case ImplicitConversionSequence::AmbiguousConversion: |
| 5848 | case ImplicitConversionSequence::EllipsisConversion: |
| 5849 | break; |
| 5850 | |
| 5851 | case ImplicitConversionSequence::UserDefinedConversion: |
| 5852 | dropPointerConversion(ICS.UserDefined.After); |
| 5853 | break; |
| 5854 | |
| 5855 | case ImplicitConversionSequence::StandardConversion: |
| 5856 | dropPointerConversion(ICS.Standard); |
| 5857 | break; |
| 5858 | } |
| 5859 | |
| 5860 | return ICS; |
| 5861 | } |
| 5862 | |
| 5863 | /// PerformContextuallyConvertToObjCPointer - Perform a contextual |
| 5864 | /// conversion of the expression From to an Objective-C pointer type. |
| 5865 | /// Returns a valid but null ExprResult if no conversion sequence exists. |
| 5866 | ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) { |
| 5867 | if (checkPlaceholderForOverload(*this, From)) |
| 5868 | return ExprError(); |
| 5869 | |
| 5870 | QualType Ty = Context.getObjCIdType(); |
| 5871 | ImplicitConversionSequence ICS = |
| 5872 | TryContextuallyConvertToObjCPointer(*this, From); |
| 5873 | if (!ICS.isBad()) |
| 5874 | return PerformImplicitConversion(From, Ty, ICS, AA_Converting); |
| 5875 | return ExprResult(); |
| 5876 | } |
| 5877 | |
| 5878 | /// Determine whether the provided type is an integral type, or an enumeration |
| 5879 | /// type of a permitted flavor. |
| 5880 | bool Sema::ICEConvertDiagnoser::match(QualType T) { |
| 5881 | return AllowScopedEnumerations ? T->isIntegralOrEnumerationType() |
| 5882 | : T->isIntegralOrUnscopedEnumerationType(); |
| 5883 | } |
| 5884 | |
| 5885 | static ExprResult |
| 5886 | diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From, |
| 5887 | Sema::ContextualImplicitConverter &Converter, |
| 5888 | QualType T, UnresolvedSetImpl &ViableConversions) { |
| 5889 | |
| 5890 | if (Converter.Suppress) |
| 5891 | return ExprError(); |
| 5892 | |
| 5893 | Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange(); |
| 5894 | for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { |
| 5895 | CXXConversionDecl *Conv = |
| 5896 | cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); |
| 5897 | QualType ConvTy = Conv->getConversionType().getNonReferenceType(); |
| 5898 | Converter.noteAmbiguous(SemaRef, Conv, ConvTy); |
| 5899 | } |
| 5900 | return From; |
| 5901 | } |
| 5902 | |
| 5903 | static bool |
| 5904 | diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From, |
| 5905 | Sema::ContextualImplicitConverter &Converter, |
| 5906 | QualType T, bool HadMultipleCandidates, |
| 5907 | UnresolvedSetImpl &ExplicitConversions) { |
| 5908 | if (ExplicitConversions.size() == 1 && !Converter.Suppress) { |
| 5909 | DeclAccessPair Found = ExplicitConversions[0]; |
| 5910 | CXXConversionDecl *Conversion = |
| 5911 | cast<CXXConversionDecl>(Found->getUnderlyingDecl()); |
| 5912 | |
| 5913 | // The user probably meant to invoke the given explicit |
| 5914 | // conversion; use it. |
| 5915 | QualType ConvTy = Conversion->getConversionType().getNonReferenceType(); |
| 5916 | std::string TypeStr; |
| 5917 | ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy()); |
| 5918 | |
| 5919 | Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy) |
| 5920 | << FixItHint::CreateInsertion(From->getBeginLoc(), |
| 5921 | "static_cast<" + TypeStr + ">(") |
| 5922 | << FixItHint::CreateInsertion( |
| 5923 | SemaRef.getLocForEndOfToken(From->getEndLoc()), ")"); |
| 5924 | Converter.noteExplicitConv(SemaRef, Conversion, ConvTy); |
| 5925 | |
| 5926 | // If we aren't in a SFINAE context, build a call to the |
| 5927 | // explicit conversion function. |
| 5928 | if (SemaRef.isSFINAEContext()) |
| 5929 | return true; |
| 5930 | |
| 5931 | SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found); |
| 5932 | ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion, |
| 5933 | HadMultipleCandidates); |
| 5934 | if (Result.isInvalid()) |
| 5935 | return true; |
| 5936 | // Record usage of conversion in an implicit cast. |
| 5937 | From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(), |
| 5938 | CK_UserDefinedConversion, Result.get(), |
| 5939 | nullptr, Result.get()->getValueKind(), |
| 5940 | SemaRef.CurFPFeatureOverrides()); |
| 5941 | } |
| 5942 | return false; |
| 5943 | } |
| 5944 | |
| 5945 | static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From, |
| 5946 | Sema::ContextualImplicitConverter &Converter, |
| 5947 | QualType T, bool HadMultipleCandidates, |
| 5948 | DeclAccessPair &Found) { |
| 5949 | CXXConversionDecl *Conversion = |
| 5950 | cast<CXXConversionDecl>(Found->getUnderlyingDecl()); |
| 5951 | SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found); |
| 5952 | |
| 5953 | QualType ToType = Conversion->getConversionType().getNonReferenceType(); |
| 5954 | if (!Converter.SuppressConversion) { |
| 5955 | if (SemaRef.isSFINAEContext()) |
| 5956 | return true; |
| 5957 | |
| 5958 | Converter.diagnoseConversion(SemaRef, Loc, T, ToType) |
| 5959 | << From->getSourceRange(); |
| 5960 | } |
| 5961 | |
| 5962 | ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion, |
| 5963 | HadMultipleCandidates); |
| 5964 | if (Result.isInvalid()) |
| 5965 | return true; |
| 5966 | // Record usage of conversion in an implicit cast. |
| 5967 | From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(), |
| 5968 | CK_UserDefinedConversion, Result.get(), |
| 5969 | nullptr, Result.get()->getValueKind(), |
| 5970 | SemaRef.CurFPFeatureOverrides()); |
| 5971 | return false; |
| 5972 | } |
| 5973 | |
| 5974 | static ExprResult finishContextualImplicitConversion( |
| 5975 | Sema &SemaRef, SourceLocation Loc, Expr *From, |
| 5976 | Sema::ContextualImplicitConverter &Converter) { |
| 5977 | if (!Converter.match(From->getType()) && !Converter.Suppress) |
| 5978 | Converter.diagnoseNoMatch(SemaRef, Loc, From->getType()) |
| 5979 | << From->getSourceRange(); |
| 5980 | |
| 5981 | return SemaRef.DefaultLvalueConversion(From); |
| 5982 | } |
| 5983 | |
| 5984 | static void |
| 5985 | collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType, |
| 5986 | UnresolvedSetImpl &ViableConversions, |
| 5987 | OverloadCandidateSet &CandidateSet) { |
| 5988 | for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { |
| 5989 | DeclAccessPair FoundDecl = ViableConversions[I]; |
| 5990 | NamedDecl *D = FoundDecl.getDecl(); |
| 5991 | CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); |
| 5992 | if (isa<UsingShadowDecl>(D)) |
| 5993 | D = cast<UsingShadowDecl>(D)->getTargetDecl(); |
| 5994 | |
| 5995 | CXXConversionDecl *Conv; |
| 5996 | FunctionTemplateDecl *ConvTemplate; |
| 5997 | if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) |
| 5998 | Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); |
| 5999 | else |
| 6000 | Conv = cast<CXXConversionDecl>(D); |
| 6001 | |
| 6002 | if (ConvTemplate) |
| 6003 | SemaRef.AddTemplateConversionCandidate( |
| 6004 | ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet, |
| 6005 | /*AllowObjCConversionOnExplicit=*/false, /*AllowExplicit*/ true); |
| 6006 | else |
| 6007 | SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From, |
| 6008 | ToType, CandidateSet, |
| 6009 | /*AllowObjCConversionOnExplicit=*/false, |
| 6010 | /*AllowExplicit*/ true); |
| 6011 | } |
| 6012 | } |
| 6013 | |
| 6014 | /// Attempt to convert the given expression to a type which is accepted |
| 6015 | /// by the given converter. |
| 6016 | /// |
| 6017 | /// This routine will attempt to convert an expression of class type to a |
| 6018 | /// type accepted by the specified converter. In C++11 and before, the class |
| 6019 | /// must have a single non-explicit conversion function converting to a matching |
| 6020 | /// type. In C++1y, there can be multiple such conversion functions, but only |
| 6021 | /// one target type. |
| 6022 | /// |
| 6023 | /// \param Loc The source location of the construct that requires the |
| 6024 | /// conversion. |
| 6025 | /// |
| 6026 | /// \param From The expression we're converting from. |
| 6027 | /// |
| 6028 | /// \param Converter Used to control and diagnose the conversion process. |
| 6029 | /// |
| 6030 | /// \returns The expression, converted to an integral or enumeration type if |
| 6031 | /// successful. |
| 6032 | ExprResult Sema::PerformContextualImplicitConversion( |
| 6033 | SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) { |
| 6034 | // We can't perform any more checking for type-dependent expressions. |
| 6035 | if (From->isTypeDependent()) |
| 6036 | return From; |
| 6037 | |
| 6038 | // Process placeholders immediately. |
| 6039 | if (From->hasPlaceholderType()) { |
| 6040 | ExprResult result = CheckPlaceholderExpr(From); |
| 6041 | if (result.isInvalid()) |
| 6042 | return result; |
| 6043 | From = result.get(); |
| 6044 | } |
| 6045 | |
| 6046 | // If the expression already has a matching type, we're golden. |
| 6047 | QualType T = From->getType(); |
| 6048 | if (Converter.match(T)) |
| 6049 | return DefaultLvalueConversion(From); |
| 6050 | |
| 6051 | // FIXME: Check for missing '()' if T is a function type? |
| 6052 | |
| 6053 | // We can only perform contextual implicit conversions on objects of class |
| 6054 | // type. |
| 6055 | const RecordType *RecordTy = T->getAs<RecordType>(); |
| 6056 | if (!RecordTy || !getLangOpts().CPlusPlus) { |
| 6057 | if (!Converter.Suppress) |
| 6058 | Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange(); |
| 6059 | return From; |
| 6060 | } |
| 6061 | |
| 6062 | // We must have a complete class type. |
| 6063 | struct TypeDiagnoserPartialDiag : TypeDiagnoser { |
| 6064 | ContextualImplicitConverter &Converter; |
| 6065 | Expr *From; |
| 6066 | |
| 6067 | TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From) |
| 6068 | : Converter(Converter), From(From) {} |
| 6069 | |
| 6070 | void diagnose(Sema &S, SourceLocation Loc, QualType T) override { |
| 6071 | Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange(); |
| 6072 | } |
| 6073 | } IncompleteDiagnoser(Converter, From); |
| 6074 | |
| 6075 | if (Converter.Suppress ? !isCompleteType(Loc, T) |
| 6076 | : RequireCompleteType(Loc, T, IncompleteDiagnoser)) |
| 6077 | return From; |
| 6078 | |
| 6079 | // Look for a conversion to an integral or enumeration type. |
| 6080 | UnresolvedSet<4> |
| 6081 | ViableConversions; // These are *potentially* viable in C++1y. |
| 6082 | UnresolvedSet<4> ExplicitConversions; |
| 6083 | const auto &Conversions = |
| 6084 | cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); |
| 6085 | |
| 6086 | bool HadMultipleCandidates = |
| 6087 | (std::distance(Conversions.begin(), Conversions.end()) > 1); |
| 6088 |