| File: | src/gnu/usr.bin/clang/libclangLex/../../../llvm/clang/lib/Lex/LiteralSupport.cpp |
| Warning: | line 720, column 11 Value stored to 'HasSize' is never read |
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| 1 | //===--- LiteralSupport.cpp - Code to parse and process literals ----------===// |
| 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 implements the NumericLiteralParser, CharLiteralParser, and |
| 10 | // StringLiteralParser interfaces. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "clang/Lex/LiteralSupport.h" |
| 15 | #include "clang/Basic/CharInfo.h" |
| 16 | #include "clang/Basic/LangOptions.h" |
| 17 | #include "clang/Basic/SourceLocation.h" |
| 18 | #include "clang/Basic/TargetInfo.h" |
| 19 | #include "clang/Lex/LexDiagnostic.h" |
| 20 | #include "clang/Lex/Lexer.h" |
| 21 | #include "clang/Lex/Preprocessor.h" |
| 22 | #include "clang/Lex/Token.h" |
| 23 | #include "llvm/ADT/APInt.h" |
| 24 | #include "llvm/ADT/SmallVector.h" |
| 25 | #include "llvm/ADT/StringExtras.h" |
| 26 | #include "llvm/ADT/StringSwitch.h" |
| 27 | #include "llvm/Support/ConvertUTF.h" |
| 28 | #include "llvm/Support/Error.h" |
| 29 | #include "llvm/Support/ErrorHandling.h" |
| 30 | #include <algorithm> |
| 31 | #include <cassert> |
| 32 | #include <cstddef> |
| 33 | #include <cstdint> |
| 34 | #include <cstring> |
| 35 | #include <string> |
| 36 | |
| 37 | using namespace clang; |
| 38 | |
| 39 | static unsigned getCharWidth(tok::TokenKind kind, const TargetInfo &Target) { |
| 40 | switch (kind) { |
| 41 | default: llvm_unreachable("Unknown token type!")__builtin_unreachable(); |
| 42 | case tok::char_constant: |
| 43 | case tok::string_literal: |
| 44 | case tok::utf8_char_constant: |
| 45 | case tok::utf8_string_literal: |
| 46 | return Target.getCharWidth(); |
| 47 | case tok::wide_char_constant: |
| 48 | case tok::wide_string_literal: |
| 49 | return Target.getWCharWidth(); |
| 50 | case tok::utf16_char_constant: |
| 51 | case tok::utf16_string_literal: |
| 52 | return Target.getChar16Width(); |
| 53 | case tok::utf32_char_constant: |
| 54 | case tok::utf32_string_literal: |
| 55 | return Target.getChar32Width(); |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | static CharSourceRange MakeCharSourceRange(const LangOptions &Features, |
| 60 | FullSourceLoc TokLoc, |
| 61 | const char *TokBegin, |
| 62 | const char *TokRangeBegin, |
| 63 | const char *TokRangeEnd) { |
| 64 | SourceLocation Begin = |
| 65 | Lexer::AdvanceToTokenCharacter(TokLoc, TokRangeBegin - TokBegin, |
| 66 | TokLoc.getManager(), Features); |
| 67 | SourceLocation End = |
| 68 | Lexer::AdvanceToTokenCharacter(Begin, TokRangeEnd - TokRangeBegin, |
| 69 | TokLoc.getManager(), Features); |
| 70 | return CharSourceRange::getCharRange(Begin, End); |
| 71 | } |
| 72 | |
| 73 | /// Produce a diagnostic highlighting some portion of a literal. |
| 74 | /// |
| 75 | /// Emits the diagnostic \p DiagID, highlighting the range of characters from |
| 76 | /// \p TokRangeBegin (inclusive) to \p TokRangeEnd (exclusive), which must be |
| 77 | /// a substring of a spelling buffer for the token beginning at \p TokBegin. |
| 78 | static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, |
| 79 | const LangOptions &Features, FullSourceLoc TokLoc, |
| 80 | const char *TokBegin, const char *TokRangeBegin, |
| 81 | const char *TokRangeEnd, unsigned DiagID) { |
| 82 | SourceLocation Begin = |
| 83 | Lexer::AdvanceToTokenCharacter(TokLoc, TokRangeBegin - TokBegin, |
| 84 | TokLoc.getManager(), Features); |
| 85 | return Diags->Report(Begin, DiagID) << |
| 86 | MakeCharSourceRange(Features, TokLoc, TokBegin, TokRangeBegin, TokRangeEnd); |
| 87 | } |
| 88 | |
| 89 | /// ProcessCharEscape - Parse a standard C escape sequence, which can occur in |
| 90 | /// either a character or a string literal. |
| 91 | static unsigned ProcessCharEscape(const char *ThisTokBegin, |
| 92 | const char *&ThisTokBuf, |
| 93 | const char *ThisTokEnd, bool &HadError, |
| 94 | FullSourceLoc Loc, unsigned CharWidth, |
| 95 | DiagnosticsEngine *Diags, |
| 96 | const LangOptions &Features) { |
| 97 | const char *EscapeBegin = ThisTokBuf; |
| 98 | |
| 99 | // Skip the '\' char. |
| 100 | ++ThisTokBuf; |
| 101 | |
| 102 | // We know that this character can't be off the end of the buffer, because |
| 103 | // that would have been \", which would not have been the end of string. |
| 104 | unsigned ResultChar = *ThisTokBuf++; |
| 105 | switch (ResultChar) { |
| 106 | // These map to themselves. |
| 107 | case '\\': case '\'': case '"': case '?': break; |
| 108 | |
| 109 | // These have fixed mappings. |
| 110 | case 'a': |
| 111 | // TODO: K&R: the meaning of '\\a' is different in traditional C |
| 112 | ResultChar = 7; |
| 113 | break; |
| 114 | case 'b': |
| 115 | ResultChar = 8; |
| 116 | break; |
| 117 | case 'e': |
| 118 | if (Diags) |
| 119 | Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf, |
| 120 | diag::ext_nonstandard_escape) << "e"; |
| 121 | ResultChar = 27; |
| 122 | break; |
| 123 | case 'E': |
| 124 | if (Diags) |
| 125 | Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf, |
| 126 | diag::ext_nonstandard_escape) << "E"; |
| 127 | ResultChar = 27; |
| 128 | break; |
| 129 | case 'f': |
| 130 | ResultChar = 12; |
| 131 | break; |
| 132 | case 'n': |
| 133 | ResultChar = 10; |
| 134 | break; |
| 135 | case 'r': |
| 136 | ResultChar = 13; |
| 137 | break; |
| 138 | case 't': |
| 139 | ResultChar = 9; |
| 140 | break; |
| 141 | case 'v': |
| 142 | ResultChar = 11; |
| 143 | break; |
| 144 | case 'x': { // Hex escape. |
| 145 | ResultChar = 0; |
| 146 | if (ThisTokBuf == ThisTokEnd || !isHexDigit(*ThisTokBuf)) { |
| 147 | if (Diags) |
| 148 | Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf, |
| 149 | diag::err_hex_escape_no_digits) << "x"; |
| 150 | HadError = true; |
| 151 | break; |
| 152 | } |
| 153 | |
| 154 | // Hex escapes are a maximal series of hex digits. |
| 155 | bool Overflow = false; |
| 156 | for (; ThisTokBuf != ThisTokEnd; ++ThisTokBuf) { |
| 157 | int CharVal = llvm::hexDigitValue(ThisTokBuf[0]); |
| 158 | if (CharVal == -1) break; |
| 159 | // About to shift out a digit? |
| 160 | if (ResultChar & 0xF0000000) |
| 161 | Overflow = true; |
| 162 | ResultChar <<= 4; |
| 163 | ResultChar |= CharVal; |
| 164 | } |
| 165 | |
| 166 | // See if any bits will be truncated when evaluated as a character. |
| 167 | if (CharWidth != 32 && (ResultChar >> CharWidth) != 0) { |
| 168 | Overflow = true; |
| 169 | ResultChar &= ~0U >> (32-CharWidth); |
| 170 | } |
| 171 | |
| 172 | // Check for overflow. |
| 173 | if (Overflow && Diags) // Too many digits to fit in |
| 174 | Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf, |
| 175 | diag::err_escape_too_large) << 0; |
| 176 | break; |
| 177 | } |
| 178 | case '0': case '1': case '2': case '3': |
| 179 | case '4': case '5': case '6': case '7': { |
| 180 | // Octal escapes. |
| 181 | --ThisTokBuf; |
| 182 | ResultChar = 0; |
| 183 | |
| 184 | // Octal escapes are a series of octal digits with maximum length 3. |
| 185 | // "\0123" is a two digit sequence equal to "\012" "3". |
| 186 | unsigned NumDigits = 0; |
| 187 | do { |
| 188 | ResultChar <<= 3; |
| 189 | ResultChar |= *ThisTokBuf++ - '0'; |
| 190 | ++NumDigits; |
| 191 | } while (ThisTokBuf != ThisTokEnd && NumDigits < 3 && |
| 192 | ThisTokBuf[0] >= '0' && ThisTokBuf[0] <= '7'); |
| 193 | |
| 194 | // Check for overflow. Reject '\777', but not L'\777'. |
| 195 | if (CharWidth != 32 && (ResultChar >> CharWidth) != 0) { |
| 196 | if (Diags) |
| 197 | Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf, |
| 198 | diag::err_escape_too_large) << 1; |
| 199 | ResultChar &= ~0U >> (32-CharWidth); |
| 200 | } |
| 201 | break; |
| 202 | } |
| 203 | |
| 204 | // Otherwise, these are not valid escapes. |
| 205 | case '(': case '{': case '[': case '%': |
| 206 | // GCC accepts these as extensions. We warn about them as such though. |
| 207 | if (Diags) |
| 208 | Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf, |
| 209 | diag::ext_nonstandard_escape) |
| 210 | << std::string(1, ResultChar); |
| 211 | break; |
| 212 | default: |
| 213 | if (!Diags) |
| 214 | break; |
| 215 | |
| 216 | if (isPrintable(ResultChar)) |
| 217 | Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf, |
| 218 | diag::ext_unknown_escape) |
| 219 | << std::string(1, ResultChar); |
| 220 | else |
| 221 | Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf, |
| 222 | diag::ext_unknown_escape) |
| 223 | << "x" + llvm::utohexstr(ResultChar); |
| 224 | break; |
| 225 | } |
| 226 | |
| 227 | return ResultChar; |
| 228 | } |
| 229 | |
| 230 | static void appendCodePoint(unsigned Codepoint, |
| 231 | llvm::SmallVectorImpl<char> &Str) { |
| 232 | char ResultBuf[4]; |
| 233 | char *ResultPtr = ResultBuf; |
| 234 | bool Res = llvm::ConvertCodePointToUTF8(Codepoint, ResultPtr); |
| 235 | (void)Res; |
| 236 | assert(Res && "Unexpected conversion failure")((void)0); |
| 237 | Str.append(ResultBuf, ResultPtr); |
| 238 | } |
| 239 | |
| 240 | void clang::expandUCNs(SmallVectorImpl<char> &Buf, StringRef Input) { |
| 241 | for (StringRef::iterator I = Input.begin(), E = Input.end(); I != E; ++I) { |
| 242 | if (*I != '\\') { |
| 243 | Buf.push_back(*I); |
| 244 | continue; |
| 245 | } |
| 246 | |
| 247 | ++I; |
| 248 | assert(*I == 'u' || *I == 'U')((void)0); |
| 249 | |
| 250 | unsigned NumHexDigits; |
| 251 | if (*I == 'u') |
| 252 | NumHexDigits = 4; |
| 253 | else |
| 254 | NumHexDigits = 8; |
| 255 | |
| 256 | assert(I + NumHexDigits <= E)((void)0); |
| 257 | |
| 258 | uint32_t CodePoint = 0; |
| 259 | for (++I; NumHexDigits != 0; ++I, --NumHexDigits) { |
| 260 | unsigned Value = llvm::hexDigitValue(*I); |
| 261 | assert(Value != -1U)((void)0); |
| 262 | |
| 263 | CodePoint <<= 4; |
| 264 | CodePoint += Value; |
| 265 | } |
| 266 | |
| 267 | appendCodePoint(CodePoint, Buf); |
| 268 | --I; |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | /// ProcessUCNEscape - Read the Universal Character Name, check constraints and |
| 273 | /// return the UTF32. |
| 274 | static bool ProcessUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf, |
| 275 | const char *ThisTokEnd, |
| 276 | uint32_t &UcnVal, unsigned short &UcnLen, |
| 277 | FullSourceLoc Loc, DiagnosticsEngine *Diags, |
| 278 | const LangOptions &Features, |
| 279 | bool in_char_string_literal = false) { |
| 280 | const char *UcnBegin = ThisTokBuf; |
| 281 | |
| 282 | // Skip the '\u' char's. |
| 283 | ThisTokBuf += 2; |
| 284 | |
| 285 | if (ThisTokBuf == ThisTokEnd || !isHexDigit(*ThisTokBuf)) { |
| 286 | if (Diags) |
| 287 | Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf, |
| 288 | diag::err_hex_escape_no_digits) << StringRef(&ThisTokBuf[-1], 1); |
| 289 | return false; |
| 290 | } |
| 291 | UcnLen = (ThisTokBuf[-1] == 'u' ? 4 : 8); |
| 292 | unsigned short UcnLenSave = UcnLen; |
| 293 | for (; ThisTokBuf != ThisTokEnd && UcnLenSave; ++ThisTokBuf, UcnLenSave--) { |
| 294 | int CharVal = llvm::hexDigitValue(ThisTokBuf[0]); |
| 295 | if (CharVal == -1) break; |
| 296 | UcnVal <<= 4; |
| 297 | UcnVal |= CharVal; |
| 298 | } |
| 299 | // If we didn't consume the proper number of digits, there is a problem. |
| 300 | if (UcnLenSave) { |
| 301 | if (Diags) |
| 302 | Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf, |
| 303 | diag::err_ucn_escape_incomplete); |
| 304 | return false; |
| 305 | } |
| 306 | |
| 307 | // Check UCN constraints (C99 6.4.3p2) [C++11 lex.charset p2] |
| 308 | if ((0xD800 <= UcnVal && UcnVal <= 0xDFFF) || // surrogate codepoints |
| 309 | UcnVal > 0x10FFFF) { // maximum legal UTF32 value |
| 310 | if (Diags) |
| 311 | Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf, |
| 312 | diag::err_ucn_escape_invalid); |
| 313 | return false; |
| 314 | } |
| 315 | |
| 316 | // C++11 allows UCNs that refer to control characters and basic source |
| 317 | // characters inside character and string literals |
| 318 | if (UcnVal < 0xa0 && |
| 319 | (UcnVal != 0x24 && UcnVal != 0x40 && UcnVal != 0x60)) { // $, @, ` |
| 320 | bool IsError = (!Features.CPlusPlus11 || !in_char_string_literal); |
| 321 | if (Diags) { |
| 322 | char BasicSCSChar = UcnVal; |
| 323 | if (UcnVal >= 0x20 && UcnVal < 0x7f) |
| 324 | Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf, |
| 325 | IsError ? diag::err_ucn_escape_basic_scs : |
| 326 | diag::warn_cxx98_compat_literal_ucn_escape_basic_scs) |
| 327 | << StringRef(&BasicSCSChar, 1); |
| 328 | else |
| 329 | Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf, |
| 330 | IsError ? diag::err_ucn_control_character : |
| 331 | diag::warn_cxx98_compat_literal_ucn_control_character); |
| 332 | } |
| 333 | if (IsError) |
| 334 | return false; |
| 335 | } |
| 336 | |
| 337 | if (!Features.CPlusPlus && !Features.C99 && Diags) |
| 338 | Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf, |
| 339 | diag::warn_ucn_not_valid_in_c89_literal); |
| 340 | |
| 341 | return true; |
| 342 | } |
| 343 | |
| 344 | /// MeasureUCNEscape - Determine the number of bytes within the resulting string |
| 345 | /// which this UCN will occupy. |
| 346 | static int MeasureUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf, |
| 347 | const char *ThisTokEnd, unsigned CharByteWidth, |
| 348 | const LangOptions &Features, bool &HadError) { |
| 349 | // UTF-32: 4 bytes per escape. |
| 350 | if (CharByteWidth == 4) |
| 351 | return 4; |
| 352 | |
| 353 | uint32_t UcnVal = 0; |
| 354 | unsigned short UcnLen = 0; |
| 355 | FullSourceLoc Loc; |
| 356 | |
| 357 | if (!ProcessUCNEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd, UcnVal, |
| 358 | UcnLen, Loc, nullptr, Features, true)) { |
| 359 | HadError = true; |
| 360 | return 0; |
| 361 | } |
| 362 | |
| 363 | // UTF-16: 2 bytes for BMP, 4 bytes otherwise. |
| 364 | if (CharByteWidth == 2) |
| 365 | return UcnVal <= 0xFFFF ? 2 : 4; |
| 366 | |
| 367 | // UTF-8. |
| 368 | if (UcnVal < 0x80) |
| 369 | return 1; |
| 370 | if (UcnVal < 0x800) |
| 371 | return 2; |
| 372 | if (UcnVal < 0x10000) |
| 373 | return 3; |
| 374 | return 4; |
| 375 | } |
| 376 | |
| 377 | /// EncodeUCNEscape - Read the Universal Character Name, check constraints and |
| 378 | /// convert the UTF32 to UTF8 or UTF16. This is a subroutine of |
| 379 | /// StringLiteralParser. When we decide to implement UCN's for identifiers, |
| 380 | /// we will likely rework our support for UCN's. |
| 381 | static void EncodeUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf, |
| 382 | const char *ThisTokEnd, |
| 383 | char *&ResultBuf, bool &HadError, |
| 384 | FullSourceLoc Loc, unsigned CharByteWidth, |
| 385 | DiagnosticsEngine *Diags, |
| 386 | const LangOptions &Features) { |
| 387 | typedef uint32_t UTF32; |
| 388 | UTF32 UcnVal = 0; |
| 389 | unsigned short UcnLen = 0; |
| 390 | if (!ProcessUCNEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd, UcnVal, UcnLen, |
| 391 | Loc, Diags, Features, true)) { |
| 392 | HadError = true; |
| 393 | return; |
| 394 | } |
| 395 | |
| 396 | assert((CharByteWidth == 1 || CharByteWidth == 2 || CharByteWidth == 4) &&((void)0) |
| 397 | "only character widths of 1, 2, or 4 bytes supported")((void)0); |
| 398 | |
| 399 | (void)UcnLen; |
| 400 | assert((UcnLen== 4 || UcnLen== 8) && "only ucn length of 4 or 8 supported")((void)0); |
| 401 | |
| 402 | if (CharByteWidth == 4) { |
| 403 | // FIXME: Make the type of the result buffer correct instead of |
| 404 | // using reinterpret_cast. |
| 405 | llvm::UTF32 *ResultPtr = reinterpret_cast<llvm::UTF32*>(ResultBuf); |
| 406 | *ResultPtr = UcnVal; |
| 407 | ResultBuf += 4; |
| 408 | return; |
| 409 | } |
| 410 | |
| 411 | if (CharByteWidth == 2) { |
| 412 | // FIXME: Make the type of the result buffer correct instead of |
| 413 | // using reinterpret_cast. |
| 414 | llvm::UTF16 *ResultPtr = reinterpret_cast<llvm::UTF16*>(ResultBuf); |
| 415 | |
| 416 | if (UcnVal <= (UTF32)0xFFFF) { |
| 417 | *ResultPtr = UcnVal; |
| 418 | ResultBuf += 2; |
| 419 | return; |
| 420 | } |
| 421 | |
| 422 | // Convert to UTF16. |
| 423 | UcnVal -= 0x10000; |
| 424 | *ResultPtr = 0xD800 + (UcnVal >> 10); |
| 425 | *(ResultPtr+1) = 0xDC00 + (UcnVal & 0x3FF); |
| 426 | ResultBuf += 4; |
| 427 | return; |
| 428 | } |
| 429 | |
| 430 | assert(CharByteWidth == 1 && "UTF-8 encoding is only for 1 byte characters")((void)0); |
| 431 | |
| 432 | // Now that we've parsed/checked the UCN, we convert from UTF32->UTF8. |
| 433 | // The conversion below was inspired by: |
| 434 | // http://www.unicode.org/Public/PROGRAMS/CVTUTF/ConvertUTF.c |
| 435 | // First, we determine how many bytes the result will require. |
| 436 | typedef uint8_t UTF8; |
| 437 | |
| 438 | unsigned short bytesToWrite = 0; |
| 439 | if (UcnVal < (UTF32)0x80) |
| 440 | bytesToWrite = 1; |
| 441 | else if (UcnVal < (UTF32)0x800) |
| 442 | bytesToWrite = 2; |
| 443 | else if (UcnVal < (UTF32)0x10000) |
| 444 | bytesToWrite = 3; |
| 445 | else |
| 446 | bytesToWrite = 4; |
| 447 | |
| 448 | const unsigned byteMask = 0xBF; |
| 449 | const unsigned byteMark = 0x80; |
| 450 | |
| 451 | // Once the bits are split out into bytes of UTF8, this is a mask OR-ed |
| 452 | // into the first byte, depending on how many bytes follow. |
| 453 | static const UTF8 firstByteMark[5] = { |
| 454 | 0x00, 0x00, 0xC0, 0xE0, 0xF0 |
| 455 | }; |
| 456 | // Finally, we write the bytes into ResultBuf. |
| 457 | ResultBuf += bytesToWrite; |
| 458 | switch (bytesToWrite) { // note: everything falls through. |
| 459 | case 4: |
| 460 | *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6; |
| 461 | LLVM_FALLTHROUGH[[gnu::fallthrough]]; |
| 462 | case 3: |
| 463 | *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6; |
| 464 | LLVM_FALLTHROUGH[[gnu::fallthrough]]; |
| 465 | case 2: |
| 466 | *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6; |
| 467 | LLVM_FALLTHROUGH[[gnu::fallthrough]]; |
| 468 | case 1: |
| 469 | *--ResultBuf = (UTF8) (UcnVal | firstByteMark[bytesToWrite]); |
| 470 | } |
| 471 | // Update the buffer. |
| 472 | ResultBuf += bytesToWrite; |
| 473 | } |
| 474 | |
| 475 | /// integer-constant: [C99 6.4.4.1] |
| 476 | /// decimal-constant integer-suffix |
| 477 | /// octal-constant integer-suffix |
| 478 | /// hexadecimal-constant integer-suffix |
| 479 | /// binary-literal integer-suffix [GNU, C++1y] |
| 480 | /// user-defined-integer-literal: [C++11 lex.ext] |
| 481 | /// decimal-literal ud-suffix |
| 482 | /// octal-literal ud-suffix |
| 483 | /// hexadecimal-literal ud-suffix |
| 484 | /// binary-literal ud-suffix [GNU, C++1y] |
| 485 | /// decimal-constant: |
| 486 | /// nonzero-digit |
| 487 | /// decimal-constant digit |
| 488 | /// octal-constant: |
| 489 | /// 0 |
| 490 | /// octal-constant octal-digit |
| 491 | /// hexadecimal-constant: |
| 492 | /// hexadecimal-prefix hexadecimal-digit |
| 493 | /// hexadecimal-constant hexadecimal-digit |
| 494 | /// hexadecimal-prefix: one of |
| 495 | /// 0x 0X |
| 496 | /// binary-literal: |
| 497 | /// 0b binary-digit |
| 498 | /// 0B binary-digit |
| 499 | /// binary-literal binary-digit |
| 500 | /// integer-suffix: |
| 501 | /// unsigned-suffix [long-suffix] |
| 502 | /// unsigned-suffix [long-long-suffix] |
| 503 | /// long-suffix [unsigned-suffix] |
| 504 | /// long-long-suffix [unsigned-sufix] |
| 505 | /// nonzero-digit: |
| 506 | /// 1 2 3 4 5 6 7 8 9 |
| 507 | /// octal-digit: |
| 508 | /// 0 1 2 3 4 5 6 7 |
| 509 | /// hexadecimal-digit: |
| 510 | /// 0 1 2 3 4 5 6 7 8 9 |
| 511 | /// a b c d e f |
| 512 | /// A B C D E F |
| 513 | /// binary-digit: |
| 514 | /// 0 |
| 515 | /// 1 |
| 516 | /// unsigned-suffix: one of |
| 517 | /// u U |
| 518 | /// long-suffix: one of |
| 519 | /// l L |
| 520 | /// long-long-suffix: one of |
| 521 | /// ll LL |
| 522 | /// |
| 523 | /// floating-constant: [C99 6.4.4.2] |
| 524 | /// TODO: add rules... |
| 525 | /// |
| 526 | NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling, |
| 527 | SourceLocation TokLoc, |
| 528 | const SourceManager &SM, |
| 529 | const LangOptions &LangOpts, |
| 530 | const TargetInfo &Target, |
| 531 | DiagnosticsEngine &Diags) |
| 532 | : SM(SM), LangOpts(LangOpts), Diags(Diags), |
| 533 | ThisTokBegin(TokSpelling.begin()), ThisTokEnd(TokSpelling.end()) { |
| 534 | |
| 535 | // This routine assumes that the range begin/end matches the regex for integer |
| 536 | // and FP constants (specifically, the 'pp-number' regex), and assumes that |
| 537 | // the byte at "*end" is both valid and not part of the regex. Because of |
| 538 | // this, it doesn't have to check for 'overscan' in various places. |
| 539 | assert(!isPreprocessingNumberBody(*ThisTokEnd) && "didn't maximally munch?")((void)0); |
| 540 | |
| 541 | s = DigitsBegin = ThisTokBegin; |
| 542 | saw_exponent = false; |
| 543 | saw_period = false; |
| 544 | saw_ud_suffix = false; |
| 545 | saw_fixed_point_suffix = false; |
| 546 | isLong = false; |
| 547 | isUnsigned = false; |
| 548 | isLongLong = false; |
| 549 | isSizeT = false; |
| 550 | isHalf = false; |
| 551 | isFloat = false; |
| 552 | isImaginary = false; |
| 553 | isFloat16 = false; |
| 554 | isFloat128 = false; |
| 555 | MicrosoftInteger = 0; |
| 556 | isFract = false; |
| 557 | isAccum = false; |
| 558 | hadError = false; |
| 559 | |
| 560 | if (*s == '0') { // parse radix |
| 561 | ParseNumberStartingWithZero(TokLoc); |
| 562 | if (hadError) |
| 563 | return; |
| 564 | } else { // the first digit is non-zero |
| 565 | radix = 10; |
| 566 | s = SkipDigits(s); |
| 567 | if (s == ThisTokEnd) { |
| 568 | // Done. |
| 569 | } else { |
| 570 | ParseDecimalOrOctalCommon(TokLoc); |
| 571 | if (hadError) |
| 572 | return; |
| 573 | } |
| 574 | } |
| 575 | |
| 576 | SuffixBegin = s; |
| 577 | checkSeparator(TokLoc, s, CSK_AfterDigits); |
| 578 | |
| 579 | // Initial scan to lookahead for fixed point suffix. |
| 580 | if (LangOpts.FixedPoint) { |
| 581 | for (const char *c = s; c != ThisTokEnd; ++c) { |
| 582 | if (*c == 'r' || *c == 'k' || *c == 'R' || *c == 'K') { |
| 583 | saw_fixed_point_suffix = true; |
| 584 | break; |
| 585 | } |
| 586 | } |
| 587 | } |
| 588 | |
| 589 | // Parse the suffix. At this point we can classify whether we have an FP or |
| 590 | // integer constant. |
| 591 | bool isFixedPointConstant = isFixedPointLiteral(); |
| 592 | bool isFPConstant = isFloatingLiteral(); |
| 593 | bool HasSize = false; |
| 594 | |
| 595 | // Loop over all of the characters of the suffix. If we see something bad, |
| 596 | // we break out of the loop. |
| 597 | for (; s != ThisTokEnd; ++s) { |
| 598 | switch (*s) { |
| 599 | case 'R': |
| 600 | case 'r': |
| 601 | if (!LangOpts.FixedPoint) |
| 602 | break; |
| 603 | if (isFract || isAccum) break; |
| 604 | if (!(saw_period || saw_exponent)) break; |
| 605 | isFract = true; |
| 606 | continue; |
| 607 | case 'K': |
| 608 | case 'k': |
| 609 | if (!LangOpts.FixedPoint) |
| 610 | break; |
| 611 | if (isFract || isAccum) break; |
| 612 | if (!(saw_period || saw_exponent)) break; |
| 613 | isAccum = true; |
| 614 | continue; |
| 615 | case 'h': // FP Suffix for "half". |
| 616 | case 'H': |
| 617 | // OpenCL Extension v1.2 s9.5 - h or H suffix for half type. |
| 618 | if (!(LangOpts.Half || LangOpts.FixedPoint)) |
| 619 | break; |
| 620 | if (isIntegerLiteral()) break; // Error for integer constant. |
| 621 | if (HasSize) |
| 622 | break; |
| 623 | HasSize = true; |
| 624 | isHalf = true; |
| 625 | continue; // Success. |
| 626 | case 'f': // FP Suffix for "float" |
| 627 | case 'F': |
| 628 | if (!isFPConstant) break; // Error for integer constant. |
| 629 | if (HasSize) |
| 630 | break; |
| 631 | HasSize = true; |
| 632 | |
| 633 | // CUDA host and device may have different _Float16 support, therefore |
| 634 | // allows f16 literals to avoid false alarm. |
| 635 | // ToDo: more precise check for CUDA. |
| 636 | if ((Target.hasFloat16Type() || LangOpts.CUDA) && s + 2 < ThisTokEnd && |
| 637 | s[1] == '1' && s[2] == '6') { |
| 638 | s += 2; // success, eat up 2 characters. |
| 639 | isFloat16 = true; |
| 640 | continue; |
| 641 | } |
| 642 | |
| 643 | isFloat = true; |
| 644 | continue; // Success. |
| 645 | case 'q': // FP Suffix for "__float128" |
| 646 | case 'Q': |
| 647 | if (!isFPConstant) break; // Error for integer constant. |
| 648 | if (HasSize) |
| 649 | break; |
| 650 | HasSize = true; |
| 651 | isFloat128 = true; |
| 652 | continue; // Success. |
| 653 | case 'u': |
| 654 | case 'U': |
| 655 | if (isFPConstant) break; // Error for floating constant. |
| 656 | if (isUnsigned) break; // Cannot be repeated. |
| 657 | isUnsigned = true; |
| 658 | continue; // Success. |
| 659 | case 'l': |
| 660 | case 'L': |
| 661 | if (HasSize) |
| 662 | break; |
| 663 | HasSize = true; |
| 664 | |
| 665 | // Check for long long. The L's need to be adjacent and the same case. |
| 666 | if (s[1] == s[0]) { |
| 667 | assert(s + 1 < ThisTokEnd && "didn't maximally munch?")((void)0); |
| 668 | if (isFPConstant) break; // long long invalid for floats. |
| 669 | isLongLong = true; |
| 670 | ++s; // Eat both of them. |
| 671 | } else { |
| 672 | isLong = true; |
| 673 | } |
| 674 | continue; // Success. |
| 675 | case 'z': |
| 676 | case 'Z': |
| 677 | if (isFPConstant) |
| 678 | break; // Invalid for floats. |
| 679 | if (HasSize) |
| 680 | break; |
| 681 | HasSize = true; |
| 682 | isSizeT = true; |
| 683 | continue; |
| 684 | case 'i': |
| 685 | case 'I': |
| 686 | if (LangOpts.MicrosoftExt && !isFPConstant) { |
| 687 | // Allow i8, i16, i32, and i64. First, look ahead and check if |
| 688 | // suffixes are Microsoft integers and not the imaginary unit. |
| 689 | uint8_t Bits = 0; |
| 690 | size_t ToSkip = 0; |
| 691 | switch (s[1]) { |
| 692 | case '8': // i8 suffix |
| 693 | Bits = 8; |
| 694 | ToSkip = 2; |
| 695 | break; |
| 696 | case '1': |
| 697 | if (s[2] == '6') { // i16 suffix |
| 698 | Bits = 16; |
| 699 | ToSkip = 3; |
| 700 | } |
| 701 | break; |
| 702 | case '3': |
| 703 | if (s[2] == '2') { // i32 suffix |
| 704 | Bits = 32; |
| 705 | ToSkip = 3; |
| 706 | } |
| 707 | break; |
| 708 | case '6': |
| 709 | if (s[2] == '4') { // i64 suffix |
| 710 | Bits = 64; |
| 711 | ToSkip = 3; |
| 712 | } |
| 713 | break; |
| 714 | default: |
| 715 | break; |
| 716 | } |
| 717 | if (Bits) { |
| 718 | if (HasSize) |
| 719 | break; |
| 720 | HasSize = true; |
Value stored to 'HasSize' is never read | |
| 721 | MicrosoftInteger = Bits; |
| 722 | s += ToSkip; |
| 723 | assert(s <= ThisTokEnd && "didn't maximally munch?")((void)0); |
| 724 | break; |
| 725 | } |
| 726 | } |
| 727 | LLVM_FALLTHROUGH[[gnu::fallthrough]]; |
| 728 | case 'j': |
| 729 | case 'J': |
| 730 | if (isImaginary) break; // Cannot be repeated. |
| 731 | isImaginary = true; |
| 732 | continue; // Success. |
| 733 | } |
| 734 | // If we reached here, there was an error or a ud-suffix. |
| 735 | break; |
| 736 | } |
| 737 | |
| 738 | // "i", "if", and "il" are user-defined suffixes in C++1y. |
| 739 | if (s != ThisTokEnd || isImaginary) { |
| 740 | // FIXME: Don't bother expanding UCNs if !tok.hasUCN(). |
| 741 | expandUCNs(UDSuffixBuf, StringRef(SuffixBegin, ThisTokEnd - SuffixBegin)); |
| 742 | if (isValidUDSuffix(LangOpts, UDSuffixBuf)) { |
| 743 | if (!isImaginary) { |
| 744 | // Any suffix pieces we might have parsed are actually part of the |
| 745 | // ud-suffix. |
| 746 | isLong = false; |
| 747 | isUnsigned = false; |
| 748 | isLongLong = false; |
| 749 | isSizeT = false; |
| 750 | isFloat = false; |
| 751 | isFloat16 = false; |
| 752 | isHalf = false; |
| 753 | isImaginary = false; |
| 754 | MicrosoftInteger = 0; |
| 755 | saw_fixed_point_suffix = false; |
| 756 | isFract = false; |
| 757 | isAccum = false; |
| 758 | } |
| 759 | |
| 760 | saw_ud_suffix = true; |
| 761 | return; |
| 762 | } |
| 763 | |
| 764 | if (s != ThisTokEnd) { |
| 765 | // Report an error if there are any. |
| 766 | Diags.Report(Lexer::AdvanceToTokenCharacter( |
| 767 | TokLoc, SuffixBegin - ThisTokBegin, SM, LangOpts), |
| 768 | diag::err_invalid_suffix_constant) |
| 769 | << StringRef(SuffixBegin, ThisTokEnd - SuffixBegin) |
| 770 | << (isFixedPointConstant ? 2 : isFPConstant); |
| 771 | hadError = true; |
| 772 | } |
| 773 | } |
| 774 | |
| 775 | if (!hadError && saw_fixed_point_suffix) { |
| 776 | assert(isFract || isAccum)((void)0); |
| 777 | } |
| 778 | } |
| 779 | |
| 780 | /// ParseDecimalOrOctalCommon - This method is called for decimal or octal |
| 781 | /// numbers. It issues an error for illegal digits, and handles floating point |
| 782 | /// parsing. If it detects a floating point number, the radix is set to 10. |
| 783 | void NumericLiteralParser::ParseDecimalOrOctalCommon(SourceLocation TokLoc){ |
| 784 | assert((radix == 8 || radix == 10) && "Unexpected radix")((void)0); |
| 785 | |
| 786 | // If we have a hex digit other than 'e' (which denotes a FP exponent) then |
| 787 | // the code is using an incorrect base. |
| 788 | if (isHexDigit(*s) && *s != 'e' && *s != 'E' && |
| 789 | !isValidUDSuffix(LangOpts, StringRef(s, ThisTokEnd - s))) { |
| 790 | Diags.Report( |
| 791 | Lexer::AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin, SM, LangOpts), |
| 792 | diag::err_invalid_digit) |
| 793 | << StringRef(s, 1) << (radix == 8 ? 1 : 0); |
| 794 | hadError = true; |
| 795 | return; |
| 796 | } |
| 797 | |
| 798 | if (*s == '.') { |
| 799 | checkSeparator(TokLoc, s, CSK_AfterDigits); |
| 800 | s++; |
| 801 | radix = 10; |
| 802 | saw_period = true; |
| 803 | checkSeparator(TokLoc, s, CSK_BeforeDigits); |
| 804 | s = SkipDigits(s); // Skip suffix. |
| 805 | } |
| 806 | if (*s == 'e' || *s == 'E') { // exponent |
| 807 | checkSeparator(TokLoc, s, CSK_AfterDigits); |
| 808 | const char *Exponent = s; |
| 809 | s++; |
| 810 | radix = 10; |
| 811 | saw_exponent = true; |
| 812 | if (s != ThisTokEnd && (*s == '+' || *s == '-')) s++; // sign |
| 813 | const char *first_non_digit = SkipDigits(s); |
| 814 | if (containsDigits(s, first_non_digit)) { |
| 815 | checkSeparator(TokLoc, s, CSK_BeforeDigits); |
| 816 | s = first_non_digit; |
| 817 | } else { |
| 818 | if (!hadError) { |
| 819 | Diags.Report(Lexer::AdvanceToTokenCharacter( |
| 820 | TokLoc, Exponent - ThisTokBegin, SM, LangOpts), |
| 821 | diag::err_exponent_has_no_digits); |
| 822 | hadError = true; |
| 823 | } |
| 824 | return; |
| 825 | } |
| 826 | } |
| 827 | } |
| 828 | |
| 829 | /// Determine whether a suffix is a valid ud-suffix. We avoid treating reserved |
| 830 | /// suffixes as ud-suffixes, because the diagnostic experience is better if we |
| 831 | /// treat it as an invalid suffix. |
| 832 | bool NumericLiteralParser::isValidUDSuffix(const LangOptions &LangOpts, |
| 833 | StringRef Suffix) { |
| 834 | if (!LangOpts.CPlusPlus11 || Suffix.empty()) |
| 835 | return false; |
| 836 | |
| 837 | // By C++11 [lex.ext]p10, ud-suffixes starting with an '_' are always valid. |
| 838 | if (Suffix[0] == '_') |
| 839 | return true; |
| 840 | |
| 841 | // In C++11, there are no library suffixes. |
| 842 | if (!LangOpts.CPlusPlus14) |
| 843 | return false; |
| 844 | |
| 845 | // In C++14, "s", "h", "min", "ms", "us", and "ns" are used in the library. |
| 846 | // Per tweaked N3660, "il", "i", and "if" are also used in the library. |
| 847 | // In C++2a "d" and "y" are used in the library. |
| 848 | return llvm::StringSwitch<bool>(Suffix) |
| 849 | .Cases("h", "min", "s", true) |
| 850 | .Cases("ms", "us", "ns", true) |
| 851 | .Cases("il", "i", "if", true) |
| 852 | .Cases("d", "y", LangOpts.CPlusPlus20) |
| 853 | .Default(false); |
| 854 | } |
| 855 | |
| 856 | void NumericLiteralParser::checkSeparator(SourceLocation TokLoc, |
| 857 | const char *Pos, |
| 858 | CheckSeparatorKind IsAfterDigits) { |
| 859 | if (IsAfterDigits == CSK_AfterDigits) { |
| 860 | if (Pos == ThisTokBegin) |
| 861 | return; |
| 862 | --Pos; |
| 863 | } else if (Pos == ThisTokEnd) |
| 864 | return; |
| 865 | |
| 866 | if (isDigitSeparator(*Pos)) { |
| 867 | Diags.Report(Lexer::AdvanceToTokenCharacter(TokLoc, Pos - ThisTokBegin, SM, |
| 868 | LangOpts), |
| 869 | diag::err_digit_separator_not_between_digits) |
| 870 | << IsAfterDigits; |
| 871 | hadError = true; |
| 872 | } |
| 873 | } |
| 874 | |
| 875 | /// ParseNumberStartingWithZero - This method is called when the first character |
| 876 | /// of the number is found to be a zero. This means it is either an octal |
| 877 | /// number (like '04') or a hex number ('0x123a') a binary number ('0b1010') or |
| 878 | /// a floating point number (01239.123e4). Eat the prefix, determining the |
| 879 | /// radix etc. |
| 880 | void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) { |
| 881 | assert(s[0] == '0' && "Invalid method call")((void)0); |
| 882 | s++; |
| 883 | |
| 884 | int c1 = s[0]; |
| 885 | |
| 886 | // Handle a hex number like 0x1234. |
| 887 | if ((c1 == 'x' || c1 == 'X') && (isHexDigit(s[1]) || s[1] == '.')) { |
| 888 | s++; |
| 889 | assert(s < ThisTokEnd && "didn't maximally munch?")((void)0); |
| 890 | radix = 16; |
| 891 | DigitsBegin = s; |
| 892 | s = SkipHexDigits(s); |
| 893 | bool HasSignificandDigits = containsDigits(DigitsBegin, s); |
| 894 | if (s == ThisTokEnd) { |
| 895 | // Done. |
| 896 | } else if (*s == '.') { |
| 897 | s++; |
| 898 | saw_period = true; |
| 899 | const char *floatDigitsBegin = s; |
| 900 | s = SkipHexDigits(s); |
| 901 | if (containsDigits(floatDigitsBegin, s)) |
| 902 | HasSignificandDigits = true; |
| 903 | if (HasSignificandDigits) |
| 904 | checkSeparator(TokLoc, floatDigitsBegin, CSK_BeforeDigits); |
| 905 | } |
| 906 | |
| 907 | if (!HasSignificandDigits) { |
| 908 | Diags.Report(Lexer::AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin, SM, |
| 909 | LangOpts), |
| 910 | diag::err_hex_constant_requires) |
| 911 | << LangOpts.CPlusPlus << 1; |
| 912 | hadError = true; |
| 913 | return; |
| 914 | } |
| 915 | |
| 916 | // A binary exponent can appear with or with a '.'. If dotted, the |
| 917 | // binary exponent is required. |
| 918 | if (*s == 'p' || *s == 'P') { |
| 919 | checkSeparator(TokLoc, s, CSK_AfterDigits); |
| 920 | const char *Exponent = s; |
| 921 | s++; |
| 922 | saw_exponent = true; |
| 923 | if (s != ThisTokEnd && (*s == '+' || *s == '-')) s++; // sign |
| 924 | const char *first_non_digit = SkipDigits(s); |
| 925 | if (!containsDigits(s, first_non_digit)) { |
| 926 | if (!hadError) { |
| 927 | Diags.Report(Lexer::AdvanceToTokenCharacter( |
| 928 | TokLoc, Exponent - ThisTokBegin, SM, LangOpts), |
| 929 | diag::err_exponent_has_no_digits); |
| 930 | hadError = true; |
| 931 | } |
| 932 | return; |
| 933 | } |
| 934 | checkSeparator(TokLoc, s, CSK_BeforeDigits); |
| 935 | s = first_non_digit; |
| 936 | |
| 937 | if (!LangOpts.HexFloats) |
| 938 | Diags.Report(TokLoc, LangOpts.CPlusPlus |
| 939 | ? diag::ext_hex_literal_invalid |
| 940 | : diag::ext_hex_constant_invalid); |
| 941 | else if (LangOpts.CPlusPlus17) |
| 942 | Diags.Report(TokLoc, diag::warn_cxx17_hex_literal); |
| 943 | } else if (saw_period) { |
| 944 | Diags.Report(Lexer::AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin, SM, |
| 945 | LangOpts), |
| 946 | diag::err_hex_constant_requires) |
| 947 | << LangOpts.CPlusPlus << 0; |
| 948 | hadError = true; |
| 949 | } |
| 950 | return; |
| 951 | } |
| 952 | |
| 953 | // Handle simple binary numbers 0b01010 |
| 954 | if ((c1 == 'b' || c1 == 'B') && (s[1] == '0' || s[1] == '1')) { |
| 955 | // 0b101010 is a C++1y / GCC extension. |
| 956 | Diags.Report(TokLoc, LangOpts.CPlusPlus14 |
| 957 | ? diag::warn_cxx11_compat_binary_literal |
| 958 | : LangOpts.CPlusPlus ? diag::ext_binary_literal_cxx14 |
| 959 | : diag::ext_binary_literal); |
| 960 | ++s; |
| 961 | assert(s < ThisTokEnd && "didn't maximally munch?")((void)0); |
| 962 | radix = 2; |
| 963 | DigitsBegin = s; |
| 964 | s = SkipBinaryDigits(s); |
| 965 | if (s == ThisTokEnd) { |
| 966 | // Done. |
| 967 | } else if (isHexDigit(*s) && |
| 968 | !isValidUDSuffix(LangOpts, StringRef(s, ThisTokEnd - s))) { |
| 969 | Diags.Report(Lexer::AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin, SM, |
| 970 | LangOpts), |
| 971 | diag::err_invalid_digit) |
| 972 | << StringRef(s, 1) << 2; |
| 973 | hadError = true; |
| 974 | } |
| 975 | // Other suffixes will be diagnosed by the caller. |
| 976 | return; |
| 977 | } |
| 978 | |
| 979 | // For now, the radix is set to 8. If we discover that we have a |
| 980 | // floating point constant, the radix will change to 10. Octal floating |
| 981 | // point constants are not permitted (only decimal and hexadecimal). |
| 982 | radix = 8; |
| 983 | DigitsBegin = s; |
| 984 | s = SkipOctalDigits(s); |
| 985 | if (s == ThisTokEnd) |
| 986 | return; // Done, simple octal number like 01234 |
| 987 | |
| 988 | // If we have some other non-octal digit that *is* a decimal digit, see if |
| 989 | // this is part of a floating point number like 094.123 or 09e1. |
| 990 | if (isDigit(*s)) { |
| 991 | const char *EndDecimal = SkipDigits(s); |
| 992 | if (EndDecimal[0] == '.' || EndDecimal[0] == 'e' || EndDecimal[0] == 'E') { |
| 993 | s = EndDecimal; |
| 994 | radix = 10; |
| 995 | } |
| 996 | } |
| 997 | |
| 998 | ParseDecimalOrOctalCommon(TokLoc); |
| 999 | } |
| 1000 | |
| 1001 | static bool alwaysFitsInto64Bits(unsigned Radix, unsigned NumDigits) { |
| 1002 | switch (Radix) { |
| 1003 | case 2: |
| 1004 | return NumDigits <= 64; |
| 1005 | case 8: |
| 1006 | return NumDigits <= 64 / 3; // Digits are groups of 3 bits. |
| 1007 | case 10: |
| 1008 | return NumDigits <= 19; // floor(log10(2^64)) |
| 1009 | case 16: |
| 1010 | return NumDigits <= 64 / 4; // Digits are groups of 4 bits. |
| 1011 | default: |
| 1012 | llvm_unreachable("impossible Radix")__builtin_unreachable(); |
| 1013 | } |
| 1014 | } |
| 1015 | |
| 1016 | /// GetIntegerValue - Convert this numeric literal value to an APInt that |
| 1017 | /// matches Val's input width. If there is an overflow, set Val to the low bits |
| 1018 | /// of the result and return true. Otherwise, return false. |
| 1019 | bool NumericLiteralParser::GetIntegerValue(llvm::APInt &Val) { |
| 1020 | // Fast path: Compute a conservative bound on the maximum number of |
| 1021 | // bits per digit in this radix. If we can't possibly overflow a |
| 1022 | // uint64 based on that bound then do the simple conversion to |
| 1023 | // integer. This avoids the expensive overflow checking below, and |
| 1024 | // handles the common cases that matter (small decimal integers and |
| 1025 | // hex/octal values which don't overflow). |
| 1026 | const unsigned NumDigits = SuffixBegin - DigitsBegin; |
| 1027 | if (alwaysFitsInto64Bits(radix, NumDigits)) { |
| 1028 | uint64_t N = 0; |
| 1029 | for (const char *Ptr = DigitsBegin; Ptr != SuffixBegin; ++Ptr) |
| 1030 | if (!isDigitSeparator(*Ptr)) |
| 1031 | N = N * radix + llvm::hexDigitValue(*Ptr); |
| 1032 | |
| 1033 | // This will truncate the value to Val's input width. Simply check |
| 1034 | // for overflow by comparing. |
| 1035 | Val = N; |
| 1036 | return Val.getZExtValue() != N; |
| 1037 | } |
| 1038 | |
| 1039 | Val = 0; |
| 1040 | const char *Ptr = DigitsBegin; |
| 1041 | |
| 1042 | llvm::APInt RadixVal(Val.getBitWidth(), radix); |
| 1043 | llvm::APInt CharVal(Val.getBitWidth(), 0); |
| 1044 | llvm::APInt OldVal = Val; |
| 1045 | |
| 1046 | bool OverflowOccurred = false; |
| 1047 | while (Ptr < SuffixBegin) { |
| 1048 | if (isDigitSeparator(*Ptr)) { |
| 1049 | ++Ptr; |
| 1050 | continue; |
| 1051 | } |
| 1052 | |
| 1053 | unsigned C = llvm::hexDigitValue(*Ptr++); |
| 1054 | |
| 1055 | // If this letter is out of bound for this radix, reject it. |
| 1056 | assert(C < radix && "NumericLiteralParser ctor should have rejected this")((void)0); |
| 1057 | |
| 1058 | CharVal = C; |
| 1059 | |
| 1060 | // Add the digit to the value in the appropriate radix. If adding in digits |
| 1061 | // made the value smaller, then this overflowed. |
| 1062 | OldVal = Val; |
| 1063 | |
| 1064 | // Multiply by radix, did overflow occur on the multiply? |
| 1065 | Val *= RadixVal; |
| 1066 | OverflowOccurred |= Val.udiv(RadixVal) != OldVal; |
| 1067 | |
| 1068 | // Add value, did overflow occur on the value? |
| 1069 | // (a + b) ult b <=> overflow |
| 1070 | Val += CharVal; |
| 1071 | OverflowOccurred |= Val.ult(CharVal); |
| 1072 | } |
| 1073 | return OverflowOccurred; |
| 1074 | } |
| 1075 | |
| 1076 | llvm::APFloat::opStatus |
| 1077 | NumericLiteralParser::GetFloatValue(llvm::APFloat &Result) { |
| 1078 | using llvm::APFloat; |
| 1079 | |
| 1080 | unsigned n = std::min(SuffixBegin - ThisTokBegin, ThisTokEnd - ThisTokBegin); |
| 1081 | |
| 1082 | llvm::SmallString<16> Buffer; |
| 1083 | StringRef Str(ThisTokBegin, n); |
| 1084 | if (Str.find('\'') != StringRef::npos) { |
| 1085 | Buffer.reserve(n); |
| 1086 | std::remove_copy_if(Str.begin(), Str.end(), std::back_inserter(Buffer), |
| 1087 | &isDigitSeparator); |
| 1088 | Str = Buffer; |
| 1089 | } |
| 1090 | |
| 1091 | auto StatusOrErr = |
| 1092 | Result.convertFromString(Str, APFloat::rmNearestTiesToEven); |
| 1093 | assert(StatusOrErr && "Invalid floating point representation")((void)0); |
| 1094 | return !errorToBool(StatusOrErr.takeError()) ? *StatusOrErr |
| 1095 | : APFloat::opInvalidOp; |
| 1096 | } |
| 1097 | |
| 1098 | static inline bool IsExponentPart(char c) { |
| 1099 | return c == 'p' || c == 'P' || c == 'e' || c == 'E'; |
| 1100 | } |
| 1101 | |
| 1102 | bool NumericLiteralParser::GetFixedPointValue(llvm::APInt &StoreVal, unsigned Scale) { |
| 1103 | assert(radix == 16 || radix == 10)((void)0); |
| 1104 | |
| 1105 | // Find how many digits are needed to store the whole literal. |
| 1106 | unsigned NumDigits = SuffixBegin - DigitsBegin; |
| 1107 | if (saw_period) --NumDigits; |
| 1108 | |
| 1109 | // Initial scan of the exponent if it exists |
| 1110 | bool ExpOverflowOccurred = false; |
| 1111 | bool NegativeExponent = false; |
| 1112 | const char *ExponentBegin; |
| 1113 | uint64_t Exponent = 0; |
| 1114 | int64_t BaseShift = 0; |
| 1115 | if (saw_exponent) { |
| 1116 | const char *Ptr = DigitsBegin; |
| 1117 | |
| 1118 | while (!IsExponentPart(*Ptr)) ++Ptr; |
| 1119 | ExponentBegin = Ptr; |
| 1120 | ++Ptr; |
| 1121 | NegativeExponent = *Ptr == '-'; |
| 1122 | if (NegativeExponent) ++Ptr; |
| 1123 | |
| 1124 | unsigned NumExpDigits = SuffixBegin - Ptr; |
| 1125 | if (alwaysFitsInto64Bits(radix, NumExpDigits)) { |
| 1126 | llvm::StringRef ExpStr(Ptr, NumExpDigits); |
| 1127 | llvm::APInt ExpInt(/*numBits=*/64, ExpStr, /*radix=*/10); |
| 1128 | Exponent = ExpInt.getZExtValue(); |
| 1129 | } else { |
| 1130 | ExpOverflowOccurred = true; |
| 1131 | } |
| 1132 | |
| 1133 | if (NegativeExponent) BaseShift -= Exponent; |
| 1134 | else BaseShift += Exponent; |
| 1135 | } |
| 1136 | |
| 1137 | // Number of bits needed for decimal literal is |
| 1138 | // ceil(NumDigits * log2(10)) Integral part |
| 1139 | // + Scale Fractional part |
| 1140 | // + ceil(Exponent * log2(10)) Exponent |
| 1141 | // -------------------------------------------------- |
| 1142 | // ceil((NumDigits + Exponent) * log2(10)) + Scale |
| 1143 | // |
| 1144 | // But for simplicity in handling integers, we can round up log2(10) to 4, |
| 1145 | // making: |
| 1146 | // 4 * (NumDigits + Exponent) + Scale |
| 1147 | // |
| 1148 | // Number of digits needed for hexadecimal literal is |
| 1149 | // 4 * NumDigits Integral part |
| 1150 | // + Scale Fractional part |
| 1151 | // + Exponent Exponent |
| 1152 | // -------------------------------------------------- |
| 1153 | // (4 * NumDigits) + Scale + Exponent |
| 1154 | uint64_t NumBitsNeeded; |
| 1155 | if (radix == 10) |
| 1156 | NumBitsNeeded = 4 * (NumDigits + Exponent) + Scale; |
| 1157 | else |
| 1158 | NumBitsNeeded = 4 * NumDigits + Exponent + Scale; |
| 1159 | |
| 1160 | if (NumBitsNeeded > std::numeric_limits<unsigned>::max()) |
| 1161 | ExpOverflowOccurred = true; |
| 1162 | llvm::APInt Val(static_cast<unsigned>(NumBitsNeeded), 0, /*isSigned=*/false); |
| 1163 | |
| 1164 | bool FoundDecimal = false; |
| 1165 | |
| 1166 | int64_t FractBaseShift = 0; |
| 1167 | const char *End = saw_exponent ? ExponentBegin : SuffixBegin; |
| 1168 | for (const char *Ptr = DigitsBegin; Ptr < End; ++Ptr) { |
| 1169 | if (*Ptr == '.') { |
| 1170 | FoundDecimal = true; |
| 1171 | continue; |
| 1172 | } |
| 1173 | |
| 1174 | // Normal reading of an integer |
| 1175 | unsigned C = llvm::hexDigitValue(*Ptr); |
| 1176 | assert(C < radix && "NumericLiteralParser ctor should have rejected this")((void)0); |
| 1177 | |
| 1178 | Val *= radix; |
| 1179 | Val += C; |
| 1180 | |
| 1181 | if (FoundDecimal) |
| 1182 | // Keep track of how much we will need to adjust this value by from the |
| 1183 | // number of digits past the radix point. |
| 1184 | --FractBaseShift; |
| 1185 | } |
| 1186 | |
| 1187 | // For a radix of 16, we will be multiplying by 2 instead of 16. |
| 1188 | if (radix == 16) FractBaseShift *= 4; |
| 1189 | BaseShift += FractBaseShift; |
| 1190 | |
| 1191 | Val <<= Scale; |
| 1192 | |
| 1193 | uint64_t Base = (radix == 16) ? 2 : 10; |
| 1194 | if (BaseShift > 0) { |
| 1195 | for (int64_t i = 0; i < BaseShift; ++i) { |
| 1196 | Val *= Base; |
| 1197 | } |
| 1198 | } else if (BaseShift < 0) { |
| 1199 | for (int64_t i = BaseShift; i < 0 && !Val.isNullValue(); ++i) |
| 1200 | Val = Val.udiv(Base); |
| 1201 | } |
| 1202 | |
| 1203 | bool IntOverflowOccurred = false; |
| 1204 | auto MaxVal = llvm::APInt::getMaxValue(StoreVal.getBitWidth()); |
| 1205 | if (Val.getBitWidth() > StoreVal.getBitWidth()) { |
| 1206 | IntOverflowOccurred |= Val.ugt(MaxVal.zext(Val.getBitWidth())); |
| 1207 | StoreVal = Val.trunc(StoreVal.getBitWidth()); |
| 1208 | } else if (Val.getBitWidth() < StoreVal.getBitWidth()) { |
| 1209 | IntOverflowOccurred |= Val.zext(MaxVal.getBitWidth()).ugt(MaxVal); |
| 1210 | StoreVal = Val.zext(StoreVal.getBitWidth()); |
| 1211 | } else { |
| 1212 | StoreVal = Val; |
| 1213 | } |
| 1214 | |
| 1215 | return IntOverflowOccurred || ExpOverflowOccurred; |
| 1216 | } |
| 1217 | |
| 1218 | /// \verbatim |
| 1219 | /// user-defined-character-literal: [C++11 lex.ext] |
| 1220 | /// character-literal ud-suffix |
| 1221 | /// ud-suffix: |
| 1222 | /// identifier |
| 1223 | /// character-literal: [C++11 lex.ccon] |
| 1224 | /// ' c-char-sequence ' |
| 1225 | /// u' c-char-sequence ' |
| 1226 | /// U' c-char-sequence ' |
| 1227 | /// L' c-char-sequence ' |
| 1228 | /// u8' c-char-sequence ' [C++1z lex.ccon] |
| 1229 | /// c-char-sequence: |
| 1230 | /// c-char |
| 1231 | /// c-char-sequence c-char |
| 1232 | /// c-char: |
| 1233 | /// any member of the source character set except the single-quote ', |
| 1234 | /// backslash \, or new-line character |
| 1235 | /// escape-sequence |
| 1236 | /// universal-character-name |
| 1237 | /// escape-sequence: |
| 1238 | /// simple-escape-sequence |
| 1239 | /// octal-escape-sequence |
| 1240 | /// hexadecimal-escape-sequence |
| 1241 | /// simple-escape-sequence: |
| 1242 | /// one of \' \" \? \\ \a \b \f \n \r \t \v |
| 1243 | /// octal-escape-sequence: |
| 1244 | /// \ octal-digit |
| 1245 | /// \ octal-digit octal-digit |
| 1246 | /// \ octal-digit octal-digit octal-digit |
| 1247 | /// hexadecimal-escape-sequence: |
| 1248 | /// \x hexadecimal-digit |
| 1249 | /// hexadecimal-escape-sequence hexadecimal-digit |
| 1250 | /// universal-character-name: [C++11 lex.charset] |
| 1251 | /// \u hex-quad |
| 1252 | /// \U hex-quad hex-quad |
| 1253 | /// hex-quad: |
| 1254 | /// hex-digit hex-digit hex-digit hex-digit |
| 1255 | /// \endverbatim |
| 1256 | /// |
| 1257 | CharLiteralParser::CharLiteralParser(const char *begin, const char *end, |
| 1258 | SourceLocation Loc, Preprocessor &PP, |
| 1259 | tok::TokenKind kind) { |
| 1260 | // At this point we know that the character matches the regex "(L|u|U)?'.*'". |
| 1261 | HadError = false; |
| 1262 | |
| 1263 | Kind = kind; |
| 1264 | |
| 1265 | const char *TokBegin = begin; |
| 1266 | |
| 1267 | // Skip over wide character determinant. |
| 1268 | if (Kind != tok::char_constant) |
| 1269 | ++begin; |
| 1270 | if (Kind == tok::utf8_char_constant) |
| 1271 | ++begin; |
| 1272 | |
| 1273 | // Skip over the entry quote. |
| 1274 | assert(begin[0] == '\'' && "Invalid token lexed")((void)0); |
| 1275 | ++begin; |
| 1276 | |
| 1277 | // Remove an optional ud-suffix. |
| 1278 | if (end[-1] != '\'') { |
| 1279 | const char *UDSuffixEnd = end; |
| 1280 | do { |
| 1281 | --end; |
| 1282 | } while (end[-1] != '\''); |
| 1283 | // FIXME: Don't bother with this if !tok.hasUCN(). |
| 1284 | expandUCNs(UDSuffixBuf, StringRef(end, UDSuffixEnd - end)); |
| 1285 | UDSuffixOffset = end - TokBegin; |
| 1286 | } |
| 1287 | |
| 1288 | // Trim the ending quote. |
| 1289 | assert(end != begin && "Invalid token lexed")((void)0); |
| 1290 | --end; |
| 1291 | |
| 1292 | // FIXME: The "Value" is an uint64_t so we can handle char literals of |
| 1293 | // up to 64-bits. |
| 1294 | // FIXME: This extensively assumes that 'char' is 8-bits. |
| 1295 | assert(PP.getTargetInfo().getCharWidth() == 8 &&((void)0) |
| 1296 | "Assumes char is 8 bits")((void)0); |
| 1297 | assert(PP.getTargetInfo().getIntWidth() <= 64 &&((void)0) |
| 1298 | (PP.getTargetInfo().getIntWidth() & 7) == 0 &&((void)0) |
| 1299 | "Assumes sizeof(int) on target is <= 64 and a multiple of char")((void)0); |
| 1300 | assert(PP.getTargetInfo().getWCharWidth() <= 64 &&((void)0) |
| 1301 | "Assumes sizeof(wchar) on target is <= 64")((void)0); |
| 1302 | |
| 1303 | SmallVector<uint32_t, 4> codepoint_buffer; |
| 1304 | codepoint_buffer.resize(end - begin); |
| 1305 | uint32_t *buffer_begin = &codepoint_buffer.front(); |
| 1306 | uint32_t *buffer_end = buffer_begin + codepoint_buffer.size(); |
| 1307 | |
| 1308 | // Unicode escapes representing characters that cannot be correctly |
| 1309 | // represented in a single code unit are disallowed in character literals |
| 1310 | // by this implementation. |
| 1311 | uint32_t largest_character_for_kind; |
| 1312 | if (tok::wide_char_constant == Kind) { |
| 1313 | largest_character_for_kind = |
| 1314 | 0xFFFFFFFFu >> (32-PP.getTargetInfo().getWCharWidth()); |
| 1315 | } else if (tok::utf8_char_constant == Kind) { |
| 1316 | largest_character_for_kind = 0x7F; |
| 1317 | } else if (tok::utf16_char_constant == Kind) { |
| 1318 | largest_character_for_kind = 0xFFFF; |
| 1319 | } else if (tok::utf32_char_constant == Kind) { |
| 1320 | largest_character_for_kind = 0x10FFFF; |
| 1321 | } else { |
| 1322 | largest_character_for_kind = 0x7Fu; |
| 1323 | } |
| 1324 | |
| 1325 | while (begin != end) { |
| 1326 | // Is this a span of non-escape characters? |
| 1327 | if (begin[0] != '\\') { |
| 1328 | char const *start = begin; |
| 1329 | do { |
| 1330 | ++begin; |
| 1331 | } while (begin != end && *begin != '\\'); |
| 1332 | |
| 1333 | char const *tmp_in_start = start; |
| 1334 | uint32_t *tmp_out_start = buffer_begin; |
| 1335 | llvm::ConversionResult res = |
| 1336 | llvm::ConvertUTF8toUTF32(reinterpret_cast<llvm::UTF8 const **>(&start), |
| 1337 | reinterpret_cast<llvm::UTF8 const *>(begin), |
| 1338 | &buffer_begin, buffer_end, llvm::strictConversion); |
| 1339 | if (res != llvm::conversionOK) { |
| 1340 | // If we see bad encoding for unprefixed character literals, warn and |
| 1341 | // simply copy the byte values, for compatibility with gcc and |
| 1342 | // older versions of clang. |
| 1343 | bool NoErrorOnBadEncoding = isAscii(); |
| 1344 | unsigned Msg = diag::err_bad_character_encoding; |
| 1345 | if (NoErrorOnBadEncoding) |
| 1346 | Msg = diag::warn_bad_character_encoding; |
| 1347 | PP.Diag(Loc, Msg); |
| 1348 | if (NoErrorOnBadEncoding) { |
| 1349 | start = tmp_in_start; |
| 1350 | buffer_begin = tmp_out_start; |
| 1351 | for (; start != begin; ++start, ++buffer_begin) |
| 1352 | *buffer_begin = static_cast<uint8_t>(*start); |
| 1353 | } else { |
| 1354 | HadError = true; |
| 1355 | } |
| 1356 | } else { |
| 1357 | for (; tmp_out_start < buffer_begin; ++tmp_out_start) { |
| 1358 | if (*tmp_out_start > largest_character_for_kind) { |
| 1359 | HadError = true; |
| 1360 | PP.Diag(Loc, diag::err_character_too_large); |
| 1361 | } |
| 1362 | } |
| 1363 | } |
| 1364 | |
| 1365 | continue; |
| 1366 | } |
| 1367 | // Is this a Universal Character Name escape? |
| 1368 | if (begin[1] == 'u' || begin[1] == 'U') { |
| 1369 | unsigned short UcnLen = 0; |
| 1370 | if (!ProcessUCNEscape(TokBegin, begin, end, *buffer_begin, UcnLen, |
| 1371 | FullSourceLoc(Loc, PP.getSourceManager()), |
| 1372 | &PP.getDiagnostics(), PP.getLangOpts(), true)) { |
| 1373 | HadError = true; |
| 1374 | } else if (*buffer_begin > largest_character_for_kind) { |
| 1375 | HadError = true; |
| 1376 | PP.Diag(Loc, diag::err_character_too_large); |
| 1377 | } |
| 1378 | |
| 1379 | ++buffer_begin; |
| 1380 | continue; |
| 1381 | } |
| 1382 | unsigned CharWidth = getCharWidth(Kind, PP.getTargetInfo()); |
| 1383 | uint64_t result = |
| 1384 | ProcessCharEscape(TokBegin, begin, end, HadError, |
| 1385 | FullSourceLoc(Loc,PP.getSourceManager()), |
| 1386 | CharWidth, &PP.getDiagnostics(), PP.getLangOpts()); |
| 1387 | *buffer_begin++ = result; |
| 1388 | } |
| 1389 | |
| 1390 | unsigned NumCharsSoFar = buffer_begin - &codepoint_buffer.front(); |
| 1391 | |
| 1392 | if (NumCharsSoFar > 1) { |
| 1393 | if (isWide()) |
| 1394 | PP.Diag(Loc, diag::warn_extraneous_char_constant); |
| 1395 | else if (isAscii() && NumCharsSoFar == 4) |
| 1396 | PP.Diag(Loc, diag::warn_four_char_character_literal); |
| 1397 | else if (isAscii()) |
| 1398 | PP.Diag(Loc, diag::warn_multichar_character_literal); |
| 1399 | else |
| 1400 | PP.Diag(Loc, diag::err_multichar_utf_character_literal); |
| 1401 | IsMultiChar = true; |
| 1402 | } else { |
| 1403 | IsMultiChar = false; |
| 1404 | } |
| 1405 | |
| 1406 | llvm::APInt LitVal(PP.getTargetInfo().getIntWidth(), 0); |
| 1407 | |
| 1408 | // Narrow character literals act as though their value is concatenated |
| 1409 | // in this implementation, but warn on overflow. |
| 1410 | bool multi_char_too_long = false; |
| 1411 | if (isAscii() && isMultiChar()) { |
| 1412 | LitVal = 0; |
| 1413 | for (size_t i = 0; i < NumCharsSoFar; ++i) { |
| 1414 | // check for enough leading zeros to shift into |
| 1415 | multi_char_too_long |= (LitVal.countLeadingZeros() < 8); |
| 1416 | LitVal <<= 8; |
| 1417 | LitVal = LitVal + (codepoint_buffer[i] & 0xFF); |
| 1418 | } |
| 1419 | } else if (NumCharsSoFar > 0) { |
| 1420 | // otherwise just take the last character |
| 1421 | LitVal = buffer_begin[-1]; |
| 1422 | } |
| 1423 | |
| 1424 | if (!HadError && multi_char_too_long) { |
| 1425 | PP.Diag(Loc, diag::warn_char_constant_too_large); |
| 1426 | } |
| 1427 | |
| 1428 | // Transfer the value from APInt to uint64_t |
| 1429 | Value = LitVal.getZExtValue(); |
| 1430 | |
| 1431 | // If this is a single narrow character, sign extend it (e.g. '\xFF' is "-1") |
| 1432 | // if 'char' is signed for this target (C99 6.4.4.4p10). Note that multiple |
| 1433 | // character constants are not sign extended in the this implementation: |
| 1434 | // '\xFF\xFF' = 65536 and '\x0\xFF' = 255, which matches GCC. |
| 1435 | if (isAscii() && NumCharsSoFar == 1 && (Value & 128) && |
| 1436 | PP.getLangOpts().CharIsSigned) |
| 1437 | Value = (signed char)Value; |
| 1438 | } |
| 1439 | |
| 1440 | /// \verbatim |
| 1441 | /// string-literal: [C++0x lex.string] |
| 1442 | /// encoding-prefix " [s-char-sequence] " |
| 1443 | /// encoding-prefix R raw-string |
| 1444 | /// encoding-prefix: |
| 1445 | /// u8 |
| 1446 | /// u |
| 1447 | /// U |
| 1448 | /// L |
| 1449 | /// s-char-sequence: |
| 1450 | /// s-char |
| 1451 | /// s-char-sequence s-char |
| 1452 | /// s-char: |
| 1453 | /// any member of the source character set except the double-quote ", |
| 1454 | /// backslash \, or new-line character |
| 1455 | /// escape-sequence |
| 1456 | /// universal-character-name |
| 1457 | /// raw-string: |
| 1458 | /// " d-char-sequence ( r-char-sequence ) d-char-sequence " |
| 1459 | /// r-char-sequence: |
| 1460 | /// r-char |
| 1461 | /// r-char-sequence r-char |
| 1462 | /// r-char: |
| 1463 | /// any member of the source character set, except a right parenthesis ) |
| 1464 | /// followed by the initial d-char-sequence (which may be empty) |
| 1465 | /// followed by a double quote ". |
| 1466 | /// d-char-sequence: |
| 1467 | /// d-char |
| 1468 | /// d-char-sequence d-char |
| 1469 | /// d-char: |
| 1470 | /// any member of the basic source character set except: |
| 1471 | /// space, the left parenthesis (, the right parenthesis ), |
| 1472 | /// the backslash \, and the control characters representing horizontal |
| 1473 | /// tab, vertical tab, form feed, and newline. |
| 1474 | /// escape-sequence: [C++0x lex.ccon] |
| 1475 | /// simple-escape-sequence |
| 1476 | /// octal-escape-sequence |
| 1477 | /// hexadecimal-escape-sequence |
| 1478 | /// simple-escape-sequence: |
| 1479 | /// one of \' \" \? \\ \a \b \f \n \r \t \v |
| 1480 | /// octal-escape-sequence: |
| 1481 | /// \ octal-digit |
| 1482 | /// \ octal-digit octal-digit |
| 1483 | /// \ octal-digit octal-digit octal-digit |
| 1484 | /// hexadecimal-escape-sequence: |
| 1485 | /// \x hexadecimal-digit |
| 1486 | /// hexadecimal-escape-sequence hexadecimal-digit |
| 1487 | /// universal-character-name: |
| 1488 | /// \u hex-quad |
| 1489 | /// \U hex-quad hex-quad |
| 1490 | /// hex-quad: |
| 1491 | /// hex-digit hex-digit hex-digit hex-digit |
| 1492 | /// \endverbatim |
| 1493 | /// |
| 1494 | StringLiteralParser:: |
| 1495 | StringLiteralParser(ArrayRef<Token> StringToks, |
| 1496 | Preprocessor &PP, bool Complain) |
| 1497 | : SM(PP.getSourceManager()), Features(PP.getLangOpts()), |
| 1498 | Target(PP.getTargetInfo()), Diags(Complain ? &PP.getDiagnostics() :nullptr), |
| 1499 | MaxTokenLength(0), SizeBound(0), CharByteWidth(0), Kind(tok::unknown), |
| 1500 | ResultPtr(ResultBuf.data()), hadError(false), Pascal(false) { |
| 1501 | init(StringToks); |
| 1502 | } |
| 1503 | |
| 1504 | void StringLiteralParser::init(ArrayRef<Token> StringToks){ |
| 1505 | // The literal token may have come from an invalid source location (e.g. due |
| 1506 | // to a PCH error), in which case the token length will be 0. |
| 1507 | if (StringToks.empty() || StringToks[0].getLength() < 2) |
| 1508 | return DiagnoseLexingError(SourceLocation()); |
| 1509 | |
| 1510 | // Scan all of the string portions, remember the max individual token length, |
| 1511 | // computing a bound on the concatenated string length, and see whether any |
| 1512 | // piece is a wide-string. If any of the string portions is a wide-string |
| 1513 | // literal, the result is a wide-string literal [C99 6.4.5p4]. |
| 1514 | assert(!StringToks.empty() && "expected at least one token")((void)0); |
| 1515 | MaxTokenLength = StringToks[0].getLength(); |
| 1516 | assert(StringToks[0].getLength() >= 2 && "literal token is invalid!")((void)0); |
| 1517 | SizeBound = StringToks[0].getLength()-2; // -2 for "". |
| 1518 | Kind = StringToks[0].getKind(); |
| 1519 | |
| 1520 | hadError = false; |
| 1521 | |
| 1522 | // Implement Translation Phase #6: concatenation of string literals |
| 1523 | /// (C99 5.1.1.2p1). The common case is only one string fragment. |
| 1524 | for (unsigned i = 1; i != StringToks.size(); ++i) { |
| 1525 | if (StringToks[i].getLength() < 2) |
| 1526 | return DiagnoseLexingError(StringToks[i].getLocation()); |
| 1527 | |
| 1528 | // The string could be shorter than this if it needs cleaning, but this is a |
| 1529 | // reasonable bound, which is all we need. |
| 1530 | assert(StringToks[i].getLength() >= 2 && "literal token is invalid!")((void)0); |
| 1531 | SizeBound += StringToks[i].getLength()-2; // -2 for "". |
| 1532 | |
| 1533 | // Remember maximum string piece length. |
| 1534 | if (StringToks[i].getLength() > MaxTokenLength) |
| 1535 | MaxTokenLength = StringToks[i].getLength(); |
| 1536 | |
| 1537 | // Remember if we see any wide or utf-8/16/32 strings. |
| 1538 | // Also check for illegal concatenations. |
| 1539 | if (StringToks[i].isNot(Kind) && StringToks[i].isNot(tok::string_literal)) { |
| 1540 | if (isAscii()) { |
| 1541 | Kind = StringToks[i].getKind(); |
| 1542 | } else { |
| 1543 | if (Diags) |
| 1544 | Diags->Report(StringToks[i].getLocation(), |
| 1545 | diag::err_unsupported_string_concat); |
| 1546 | hadError = true; |
| 1547 | } |
| 1548 | } |
| 1549 | } |
| 1550 | |
| 1551 | // Include space for the null terminator. |
| 1552 | ++SizeBound; |
| 1553 | |
| 1554 | // TODO: K&R warning: "traditional C rejects string constant concatenation" |
| 1555 | |
| 1556 | // Get the width in bytes of char/wchar_t/char16_t/char32_t |
| 1557 | CharByteWidth = getCharWidth(Kind, Target); |
| 1558 | assert((CharByteWidth & 7) == 0 && "Assumes character size is byte multiple")((void)0); |
| 1559 | CharByteWidth /= 8; |
| 1560 | |
| 1561 | // The output buffer size needs to be large enough to hold wide characters. |
| 1562 | // This is a worst-case assumption which basically corresponds to L"" "long". |
| 1563 | SizeBound *= CharByteWidth; |
| 1564 | |
| 1565 | // Size the temporary buffer to hold the result string data. |
| 1566 | ResultBuf.resize(SizeBound); |
| 1567 | |
| 1568 | // Likewise, but for each string piece. |
| 1569 | SmallString<512> TokenBuf; |
| 1570 | TokenBuf.resize(MaxTokenLength); |
| 1571 | |
| 1572 | // Loop over all the strings, getting their spelling, and expanding them to |
| 1573 | // wide strings as appropriate. |
| 1574 | ResultPtr = &ResultBuf[0]; // Next byte to fill in. |
| 1575 | |
| 1576 | Pascal = false; |
| 1577 | |
| 1578 | SourceLocation UDSuffixTokLoc; |
| 1579 | |
| 1580 | for (unsigned i = 0, e = StringToks.size(); i != e; ++i) { |
| 1581 | const char *ThisTokBuf = &TokenBuf[0]; |
| 1582 | // Get the spelling of the token, which eliminates trigraphs, etc. We know |
| 1583 | // that ThisTokBuf points to a buffer that is big enough for the whole token |
| 1584 | // and 'spelled' tokens can only shrink. |
| 1585 | bool StringInvalid = false; |
| 1586 | unsigned ThisTokLen = |
| 1587 | Lexer::getSpelling(StringToks[i], ThisTokBuf, SM, Features, |
| 1588 | &StringInvalid); |
| 1589 | if (StringInvalid) |
| 1590 | return DiagnoseLexingError(StringToks[i].getLocation()); |
| 1591 | |
| 1592 | const char *ThisTokBegin = ThisTokBuf; |
| 1593 | const char *ThisTokEnd = ThisTokBuf+ThisTokLen; |
| 1594 | |
| 1595 | // Remove an optional ud-suffix. |
| 1596 | if (ThisTokEnd[-1] != '"') { |
| 1597 | const char *UDSuffixEnd = ThisTokEnd; |
| 1598 | do { |
| 1599 | --ThisTokEnd; |
| 1600 | } while (ThisTokEnd[-1] != '"'); |
| 1601 | |
| 1602 | StringRef UDSuffix(ThisTokEnd, UDSuffixEnd - ThisTokEnd); |
| 1603 | |
| 1604 | if (UDSuffixBuf.empty()) { |
| 1605 | if (StringToks[i].hasUCN()) |
| 1606 | expandUCNs(UDSuffixBuf, UDSuffix); |
| 1607 | else |
| 1608 | UDSuffixBuf.assign(UDSuffix); |
| 1609 | UDSuffixToken = i; |
| 1610 | UDSuffixOffset = ThisTokEnd - ThisTokBuf; |
| 1611 | UDSuffixTokLoc = StringToks[i].getLocation(); |
| 1612 | } else { |
| 1613 | SmallString<32> ExpandedUDSuffix; |
| 1614 | if (StringToks[i].hasUCN()) { |
| 1615 | expandUCNs(ExpandedUDSuffix, UDSuffix); |
| 1616 | UDSuffix = ExpandedUDSuffix; |
| 1617 | } |
| 1618 | |
| 1619 | // C++11 [lex.ext]p8: At the end of phase 6, if a string literal is the |
| 1620 | // result of a concatenation involving at least one user-defined-string- |
| 1621 | // literal, all the participating user-defined-string-literals shall |
| 1622 | // have the same ud-suffix. |
| 1623 | if (UDSuffixBuf != UDSuffix) { |
| 1624 | if (Diags) { |
| 1625 | SourceLocation TokLoc = StringToks[i].getLocation(); |
| 1626 | Diags->Report(TokLoc, diag::err_string_concat_mixed_suffix) |
| 1627 | << UDSuffixBuf << UDSuffix |
| 1628 | << SourceRange(UDSuffixTokLoc, UDSuffixTokLoc) |
| 1629 | << SourceRange(TokLoc, TokLoc); |
| 1630 | } |
| 1631 | hadError = true; |
| 1632 | } |
| 1633 | } |
| 1634 | } |
| 1635 | |
| 1636 | // Strip the end quote. |
| 1637 | --ThisTokEnd; |
| 1638 | |
| 1639 | // TODO: Input character set mapping support. |
| 1640 | |
| 1641 | // Skip marker for wide or unicode strings. |
| 1642 | if (ThisTokBuf[0] == 'L' || ThisTokBuf[0] == 'u' || ThisTokBuf[0] == 'U') { |
| 1643 | ++ThisTokBuf; |
| 1644 | // Skip 8 of u8 marker for utf8 strings. |
| 1645 | if (ThisTokBuf[0] == '8') |
| 1646 | ++ThisTokBuf; |
| 1647 | } |
| 1648 | |
| 1649 | // Check for raw string |
| 1650 | if (ThisTokBuf[0] == 'R') { |
| 1651 | if (ThisTokBuf[1] != '"') { |
| 1652 | // The file may have come from PCH and then changed after loading the |
| 1653 | // PCH; Fail gracefully. |
| 1654 | return DiagnoseLexingError(StringToks[i].getLocation()); |
| 1655 | } |
| 1656 | ThisTokBuf += 2; // skip R" |
| 1657 | |
| 1658 | // C++11 [lex.string]p2: A `d-char-sequence` shall consist of at most 16 |
| 1659 | // characters. |
| 1660 | constexpr unsigned MaxRawStrDelimLen = 16; |
| 1661 | |
| 1662 | const char *Prefix = ThisTokBuf; |
| 1663 | while (static_cast<unsigned>(ThisTokBuf - Prefix) < MaxRawStrDelimLen && |
| 1664 | ThisTokBuf[0] != '(') |
| 1665 | ++ThisTokBuf; |
| 1666 | if (ThisTokBuf[0] != '(') |
| 1667 | return DiagnoseLexingError(StringToks[i].getLocation()); |
| 1668 | ++ThisTokBuf; // skip '(' |
| 1669 | |
| 1670 | // Remove same number of characters from the end |
| 1671 | ThisTokEnd -= ThisTokBuf - Prefix; |
| 1672 | if (ThisTokEnd < ThisTokBuf) |
| 1673 | return DiagnoseLexingError(StringToks[i].getLocation()); |
| 1674 | |
| 1675 | // C++14 [lex.string]p4: A source-file new-line in a raw string literal |
| 1676 | // results in a new-line in the resulting execution string-literal. |
| 1677 | StringRef RemainingTokenSpan(ThisTokBuf, ThisTokEnd - ThisTokBuf); |
| 1678 | while (!RemainingTokenSpan.empty()) { |
| 1679 | // Split the string literal on \r\n boundaries. |
| 1680 | size_t CRLFPos = RemainingTokenSpan.find("\r\n"); |
| 1681 | StringRef BeforeCRLF = RemainingTokenSpan.substr(0, CRLFPos); |
| 1682 | StringRef AfterCRLF = RemainingTokenSpan.substr(CRLFPos); |
| 1683 | |
| 1684 | // Copy everything before the \r\n sequence into the string literal. |
| 1685 | if (CopyStringFragment(StringToks[i], ThisTokBegin, BeforeCRLF)) |
| 1686 | hadError = true; |
| 1687 | |
| 1688 | // Point into the \n inside the \r\n sequence and operate on the |
| 1689 | // remaining portion of the literal. |
| 1690 | RemainingTokenSpan = AfterCRLF.substr(1); |
| 1691 | } |
| 1692 | } else { |
| 1693 | if (ThisTokBuf[0] != '"') { |
| 1694 | // The file may have come from PCH and then changed after loading the |
| 1695 | // PCH; Fail gracefully. |
| 1696 | return DiagnoseLexingError(StringToks[i].getLocation()); |
| 1697 | } |
| 1698 | ++ThisTokBuf; // skip " |
| 1699 | |
| 1700 | // Check if this is a pascal string |
| 1701 | if (Features.PascalStrings && ThisTokBuf + 1 != ThisTokEnd && |
| 1702 | ThisTokBuf[0] == '\\' && ThisTokBuf[1] == 'p') { |
| 1703 | |
| 1704 | // If the \p sequence is found in the first token, we have a pascal string |
| 1705 | // Otherwise, if we already have a pascal string, ignore the first \p |
| 1706 | if (i == 0) { |
| 1707 | ++ThisTokBuf; |
| 1708 | Pascal = true; |
| 1709 | } else if (Pascal) |
| 1710 | ThisTokBuf += 2; |
| 1711 | } |
| 1712 | |
| 1713 | while (ThisTokBuf != ThisTokEnd) { |
| 1714 | // Is this a span of non-escape characters? |
| 1715 | if (ThisTokBuf[0] != '\\') { |
| 1716 | const char *InStart = ThisTokBuf; |
| 1717 | do { |
| 1718 | ++ThisTokBuf; |
| 1719 | } while (ThisTokBuf != ThisTokEnd && ThisTokBuf[0] != '\\'); |
| 1720 | |
| 1721 | // Copy the character span over. |
| 1722 | if (CopyStringFragment(StringToks[i], ThisTokBegin, |
| 1723 | StringRef(InStart, ThisTokBuf - InStart))) |
| 1724 | hadError = true; |
| 1725 | continue; |
| 1726 | } |
| 1727 | // Is this a Universal Character Name escape? |
| 1728 | if (ThisTokBuf[1] == 'u' || ThisTokBuf[1] == 'U') { |
| 1729 | EncodeUCNEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd, |
| 1730 | ResultPtr, hadError, |
| 1731 | FullSourceLoc(StringToks[i].getLocation(), SM), |
| 1732 | CharByteWidth, Diags, Features); |
| 1733 | continue; |
| 1734 | } |
| 1735 | // Otherwise, this is a non-UCN escape character. Process it. |
| 1736 | unsigned ResultChar = |
| 1737 | ProcessCharEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd, hadError, |
| 1738 | FullSourceLoc(StringToks[i].getLocation(), SM), |
| 1739 | CharByteWidth*8, Diags, Features); |
| 1740 | |
| 1741 | if (CharByteWidth == 4) { |
| 1742 | // FIXME: Make the type of the result buffer correct instead of |
| 1743 | // using reinterpret_cast. |
| 1744 | llvm::UTF32 *ResultWidePtr = reinterpret_cast<llvm::UTF32*>(ResultPtr); |
| 1745 | *ResultWidePtr = ResultChar; |
| 1746 | ResultPtr += 4; |
| 1747 | } else if (CharByteWidth == 2) { |
| 1748 | // FIXME: Make the type of the result buffer correct instead of |
| 1749 | // using reinterpret_cast. |
| 1750 | llvm::UTF16 *ResultWidePtr = reinterpret_cast<llvm::UTF16*>(ResultPtr); |
| 1751 | *ResultWidePtr = ResultChar & 0xFFFF; |
| 1752 | ResultPtr += 2; |
| 1753 | } else { |
| 1754 | assert(CharByteWidth == 1 && "Unexpected char width")((void)0); |
| 1755 | *ResultPtr++ = ResultChar & 0xFF; |
| 1756 | } |
| 1757 | } |
| 1758 | } |
| 1759 | } |
| 1760 | |
| 1761 | if (Pascal) { |
| 1762 | if (CharByteWidth == 4) { |
| 1763 | // FIXME: Make the type of the result buffer correct instead of |
| 1764 | // using reinterpret_cast. |
| 1765 | llvm::UTF32 *ResultWidePtr = reinterpret_cast<llvm::UTF32*>(ResultBuf.data()); |
| 1766 | ResultWidePtr[0] = GetNumStringChars() - 1; |
| 1767 | } else if (CharByteWidth == 2) { |
| 1768 | // FIXME: Make the type of the result buffer correct instead of |
| 1769 | // using reinterpret_cast. |
| 1770 | llvm::UTF16 *ResultWidePtr = reinterpret_cast<llvm::UTF16*>(ResultBuf.data()); |
| 1771 | ResultWidePtr[0] = GetNumStringChars() - 1; |
| 1772 | } else { |
| 1773 | assert(CharByteWidth == 1 && "Unexpected char width")((void)0); |
| 1774 | ResultBuf[0] = GetNumStringChars() - 1; |
| 1775 | } |
| 1776 | |
| 1777 | // Verify that pascal strings aren't too large. |
| 1778 | if (GetStringLength() > 256) { |
| 1779 | if (Diags) |
| 1780 | Diags->Report(StringToks.front().getLocation(), |
| 1781 | diag::err_pascal_string_too_long) |
| 1782 | << SourceRange(StringToks.front().getLocation(), |
| 1783 | StringToks.back().getLocation()); |
| 1784 | hadError = true; |
| 1785 | return; |
| 1786 | } |
| 1787 | } else if (Diags) { |
| 1788 | // Complain if this string literal has too many characters. |
| 1789 | unsigned MaxChars = Features.CPlusPlus? 65536 : Features.C99 ? 4095 : 509; |
| 1790 | |
| 1791 | if (GetNumStringChars() > MaxChars) |
| 1792 | Diags->Report(StringToks.front().getLocation(), |
| 1793 | diag::ext_string_too_long) |
| 1794 | << GetNumStringChars() << MaxChars |
| 1795 | << (Features.CPlusPlus ? 2 : Features.C99 ? 1 : 0) |
| 1796 | << SourceRange(StringToks.front().getLocation(), |
| 1797 | StringToks.back().getLocation()); |
| 1798 | } |
| 1799 | } |
| 1800 | |
| 1801 | static const char *resyncUTF8(const char *Err, const char *End) { |
| 1802 | if (Err == End) |
| 1803 | return End; |
| 1804 | End = Err + std::min<unsigned>(llvm::getNumBytesForUTF8(*Err), End-Err); |
| 1805 | while (++Err != End && (*Err & 0xC0) == 0x80) |
| 1806 | ; |
| 1807 | return Err; |
| 1808 | } |
| 1809 | |
| 1810 | /// This function copies from Fragment, which is a sequence of bytes |
| 1811 | /// within Tok's contents (which begin at TokBegin) into ResultPtr. |
| 1812 | /// Performs widening for multi-byte characters. |
| 1813 | bool StringLiteralParser::CopyStringFragment(const Token &Tok, |
| 1814 | const char *TokBegin, |
| 1815 | StringRef Fragment) { |
| 1816 | const llvm::UTF8 *ErrorPtrTmp; |
| 1817 | if (ConvertUTF8toWide(CharByteWidth, Fragment, ResultPtr, ErrorPtrTmp)) |
| 1818 | return false; |
| 1819 | |
| 1820 | // If we see bad encoding for unprefixed string literals, warn and |
| 1821 | // simply copy the byte values, for compatibility with gcc and older |
| 1822 | // versions of clang. |
| 1823 | bool NoErrorOnBadEncoding = isAscii(); |
| 1824 | if (NoErrorOnBadEncoding) { |
| 1825 | memcpy(ResultPtr, Fragment.data(), Fragment.size()); |
| 1826 | ResultPtr += Fragment.size(); |
| 1827 | } |
| 1828 | |
| 1829 | if (Diags) { |
| 1830 | const char *ErrorPtr = reinterpret_cast<const char *>(ErrorPtrTmp); |
| 1831 | |
| 1832 | FullSourceLoc SourceLoc(Tok.getLocation(), SM); |
| 1833 | const DiagnosticBuilder &Builder = |
| 1834 | Diag(Diags, Features, SourceLoc, TokBegin, |
| 1835 | ErrorPtr, resyncUTF8(ErrorPtr, Fragment.end()), |
| 1836 | NoErrorOnBadEncoding ? diag::warn_bad_string_encoding |
| 1837 | : diag::err_bad_string_encoding); |
| 1838 | |
| 1839 | const char *NextStart = resyncUTF8(ErrorPtr, Fragment.end()); |
| 1840 | StringRef NextFragment(NextStart, Fragment.end()-NextStart); |
| 1841 | |
| 1842 | // Decode into a dummy buffer. |
| 1843 | SmallString<512> Dummy; |
| 1844 | Dummy.reserve(Fragment.size() * CharByteWidth); |
| 1845 | char *Ptr = Dummy.data(); |
| 1846 | |
| 1847 | while (!ConvertUTF8toWide(CharByteWidth, NextFragment, Ptr, ErrorPtrTmp)) { |
| 1848 | const char *ErrorPtr = reinterpret_cast<const char *>(ErrorPtrTmp); |
| 1849 | NextStart = resyncUTF8(ErrorPtr, Fragment.end()); |
| 1850 | Builder << MakeCharSourceRange(Features, SourceLoc, TokBegin, |
| 1851 | ErrorPtr, NextStart); |
| 1852 | NextFragment = StringRef(NextStart, Fragment.end()-NextStart); |
| 1853 | } |
| 1854 | } |
| 1855 | return !NoErrorOnBadEncoding; |
| 1856 | } |
| 1857 | |
| 1858 | void StringLiteralParser::DiagnoseLexingError(SourceLocation Loc) { |
| 1859 | hadError = true; |
| 1860 | if (Diags) |
| 1861 | Diags->Report(Loc, diag::err_lexing_string); |
| 1862 | } |
| 1863 | |
| 1864 | /// getOffsetOfStringByte - This function returns the offset of the |
| 1865 | /// specified byte of the string data represented by Token. This handles |
| 1866 | /// advancing over escape sequences in the string. |
| 1867 | unsigned StringLiteralParser::getOffsetOfStringByte(const Token &Tok, |
| 1868 | unsigned ByteNo) const { |
| 1869 | // Get the spelling of the token. |
| 1870 | SmallString<32> SpellingBuffer; |
| 1871 | SpellingBuffer.resize(Tok.getLength()); |
| 1872 | |
| 1873 | bool StringInvalid = false; |
| 1874 | const char *SpellingPtr = &SpellingBuffer[0]; |
| 1875 | unsigned TokLen = Lexer::getSpelling(Tok, SpellingPtr, SM, Features, |
| 1876 | &StringInvalid); |
| 1877 | if (StringInvalid) |
| 1878 | return 0; |
| 1879 | |
| 1880 | const char *SpellingStart = SpellingPtr; |
| 1881 | const char *SpellingEnd = SpellingPtr+TokLen; |
| 1882 | |
| 1883 | // Handle UTF-8 strings just like narrow strings. |
| 1884 | if (SpellingPtr[0] == 'u' && SpellingPtr[1] == '8') |
| 1885 | SpellingPtr += 2; |
| 1886 | |
| 1887 | assert(SpellingPtr[0] != 'L' && SpellingPtr[0] != 'u' &&((void)0) |
| 1888 | SpellingPtr[0] != 'U' && "Doesn't handle wide or utf strings yet")((void)0); |
| 1889 | |
| 1890 | // For raw string literals, this is easy. |
| 1891 | if (SpellingPtr[0] == 'R') { |
| 1892 | assert(SpellingPtr[1] == '"' && "Should be a raw string literal!")((void)0); |
| 1893 | // Skip 'R"'. |
| 1894 | SpellingPtr += 2; |
| 1895 | while (*SpellingPtr != '(') { |
| 1896 | ++SpellingPtr; |
| 1897 | assert(SpellingPtr < SpellingEnd && "Missing ( for raw string literal")((void)0); |
| 1898 | } |
| 1899 | // Skip '('. |
| 1900 | ++SpellingPtr; |
| 1901 | return SpellingPtr - SpellingStart + ByteNo; |
| 1902 | } |
| 1903 | |
| 1904 | // Skip over the leading quote |
| 1905 | assert(SpellingPtr[0] == '"' && "Should be a string literal!")((void)0); |
| 1906 | ++SpellingPtr; |
| 1907 | |
| 1908 | // Skip over bytes until we find the offset we're looking for. |
| 1909 | while (ByteNo) { |
| 1910 | assert(SpellingPtr < SpellingEnd && "Didn't find byte offset!")((void)0); |
| 1911 | |
| 1912 | // Step over non-escapes simply. |
| 1913 | if (*SpellingPtr != '\\') { |
| 1914 | ++SpellingPtr; |
| 1915 | --ByteNo; |
| 1916 | continue; |
| 1917 | } |
| 1918 | |
| 1919 | // Otherwise, this is an escape character. Advance over it. |
| 1920 | bool HadError = false; |
| 1921 | if (SpellingPtr[1] == 'u' || SpellingPtr[1] == 'U') { |
| 1922 | const char *EscapePtr = SpellingPtr; |
| 1923 | unsigned Len = MeasureUCNEscape(SpellingStart, SpellingPtr, SpellingEnd, |
| 1924 | 1, Features, HadError); |
| 1925 | if (Len > ByteNo) { |
| 1926 | // ByteNo is somewhere within the escape sequence. |
| 1927 | SpellingPtr = EscapePtr; |
| 1928 | break; |
| 1929 | } |
| 1930 | ByteNo -= Len; |
| 1931 | } else { |
| 1932 | ProcessCharEscape(SpellingStart, SpellingPtr, SpellingEnd, HadError, |
| 1933 | FullSourceLoc(Tok.getLocation(), SM), |
| 1934 | CharByteWidth*8, Diags, Features); |
| 1935 | --ByteNo; |
| 1936 | } |
| 1937 | assert(!HadError && "This method isn't valid on erroneous strings")((void)0); |
| 1938 | } |
| 1939 | |
| 1940 | return SpellingPtr-SpellingStart; |
| 1941 | } |
| 1942 | |
| 1943 | /// Determine whether a suffix is a valid ud-suffix. We avoid treating reserved |
| 1944 | /// suffixes as ud-suffixes, because the diagnostic experience is better if we |
| 1945 | /// treat it as an invalid suffix. |
| 1946 | bool StringLiteralParser::isValidUDSuffix(const LangOptions &LangOpts, |
| 1947 | StringRef Suffix) { |
| 1948 | return NumericLiteralParser::isValidUDSuffix(LangOpts, Suffix) || |
| 1949 | Suffix == "sv"; |
| 1950 | } |