File: | src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/include/clang/Sema/Sema.h |
Warning: | line 2191, column 12 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); |