1 //===--- LiteralSupport.cpp - Code to parse and process literals ----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the NumericLiteralParser, CharLiteralParser, and
11 // StringLiteralParser interfaces.
13 //===----------------------------------------------------------------------===//
15 #include "clang/Lex/LiteralSupport.h"
16 #include "clang/Basic/CharInfo.h"
17 #include "clang/Basic/TargetInfo.h"
18 #include "clang/Lex/LexDiagnostic.h"
19 #include "clang/Lex/Preprocessor.h"
20 #include "llvm/ADT/StringExtras.h"
21 #include "llvm/Support/ConvertUTF.h"
22 #include "llvm/Support/ErrorHandling.h"
24 using namespace clang;
26 static unsigned getCharWidth(tok::TokenKind kind, const TargetInfo &Target) {
28 default: llvm_unreachable("Unknown token type!");
29 case tok::char_constant:
30 case tok::string_literal:
31 case tok::utf8_string_literal:
32 return Target.getCharWidth();
33 case tok::wide_char_constant:
34 case tok::wide_string_literal:
35 return Target.getWCharWidth();
36 case tok::utf16_char_constant:
37 case tok::utf16_string_literal:
38 return Target.getChar16Width();
39 case tok::utf32_char_constant:
40 case tok::utf32_string_literal:
41 return Target.getChar32Width();
45 static CharSourceRange MakeCharSourceRange(const LangOptions &Features,
48 const char *TokRangeBegin,
49 const char *TokRangeEnd) {
50 SourceLocation Begin =
51 Lexer::AdvanceToTokenCharacter(TokLoc, TokRangeBegin - TokBegin,
52 TokLoc.getManager(), Features);
54 Lexer::AdvanceToTokenCharacter(Begin, TokRangeEnd - TokRangeBegin,
55 TokLoc.getManager(), Features);
56 return CharSourceRange::getCharRange(Begin, End);
59 /// \brief Produce a diagnostic highlighting some portion of a literal.
61 /// Emits the diagnostic \p DiagID, highlighting the range of characters from
62 /// \p TokRangeBegin (inclusive) to \p TokRangeEnd (exclusive), which must be
63 /// a substring of a spelling buffer for the token beginning at \p TokBegin.
64 static DiagnosticBuilder Diag(DiagnosticsEngine *Diags,
65 const LangOptions &Features, FullSourceLoc TokLoc,
66 const char *TokBegin, const char *TokRangeBegin,
67 const char *TokRangeEnd, unsigned DiagID) {
68 SourceLocation Begin =
69 Lexer::AdvanceToTokenCharacter(TokLoc, TokRangeBegin - TokBegin,
70 TokLoc.getManager(), Features);
71 return Diags->Report(Begin, DiagID) <<
72 MakeCharSourceRange(Features, TokLoc, TokBegin, TokRangeBegin, TokRangeEnd);
75 /// ProcessCharEscape - Parse a standard C escape sequence, which can occur in
76 /// either a character or a string literal.
77 static unsigned ProcessCharEscape(const char *ThisTokBegin,
78 const char *&ThisTokBuf,
79 const char *ThisTokEnd, bool &HadError,
80 FullSourceLoc Loc, unsigned CharWidth,
81 DiagnosticsEngine *Diags,
82 const LangOptions &Features) {
83 const char *EscapeBegin = ThisTokBuf;
88 // We know that this character can't be off the end of the buffer, because
89 // that would have been \", which would not have been the end of string.
90 unsigned ResultChar = *ThisTokBuf++;
92 // These map to themselves.
93 case '\\': case '\'': case '"': case '?': break;
95 // These have fixed mappings.
97 // TODO: K&R: the meaning of '\\a' is different in traditional C
105 Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
106 diag::ext_nonstandard_escape) << "e";
111 Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
112 diag::ext_nonstandard_escape) << "E";
130 case 'x': { // Hex escape.
132 if (ThisTokBuf == ThisTokEnd || !isHexDigit(*ThisTokBuf)) {
134 Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
135 diag::err_hex_escape_no_digits) << "x";
140 // Hex escapes are a maximal series of hex digits.
141 bool Overflow = false;
142 for (; ThisTokBuf != ThisTokEnd; ++ThisTokBuf) {
143 int CharVal = llvm::hexDigitValue(ThisTokBuf[0]);
144 if (CharVal == -1) break;
145 // About to shift out a digit?
146 Overflow |= (ResultChar & 0xF0000000) ? true : false;
148 ResultChar |= CharVal;
151 // See if any bits will be truncated when evaluated as a character.
152 if (CharWidth != 32 && (ResultChar >> CharWidth) != 0) {
154 ResultChar &= ~0U >> (32-CharWidth);
157 // Check for overflow.
158 if (Overflow && Diags) // Too many digits to fit in
159 Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
160 diag::warn_hex_escape_too_large);
163 case '0': case '1': case '2': case '3':
164 case '4': case '5': case '6': case '7': {
169 // Octal escapes are a series of octal digits with maximum length 3.
170 // "\0123" is a two digit sequence equal to "\012" "3".
171 unsigned NumDigits = 0;
174 ResultChar |= *ThisTokBuf++ - '0';
176 } while (ThisTokBuf != ThisTokEnd && NumDigits < 3 &&
177 ThisTokBuf[0] >= '0' && ThisTokBuf[0] <= '7');
179 // Check for overflow. Reject '\777', but not L'\777'.
180 if (CharWidth != 32 && (ResultChar >> CharWidth) != 0) {
182 Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
183 diag::warn_octal_escape_too_large);
184 ResultChar &= ~0U >> (32-CharWidth);
189 // Otherwise, these are not valid escapes.
190 case '(': case '{': case '[': case '%':
191 // GCC accepts these as extensions. We warn about them as such though.
193 Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
194 diag::ext_nonstandard_escape)
195 << std::string(1, ResultChar);
201 if (isPrintable(ResultChar))
202 Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
203 diag::ext_unknown_escape)
204 << std::string(1, ResultChar);
206 Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
207 diag::ext_unknown_escape)
208 << "x" + llvm::utohexstr(ResultChar);
215 /// ProcessUCNEscape - Read the Universal Character Name, check constraints and
216 /// return the UTF32.
217 static bool ProcessUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf,
218 const char *ThisTokEnd,
219 uint32_t &UcnVal, unsigned short &UcnLen,
220 FullSourceLoc Loc, DiagnosticsEngine *Diags,
221 const LangOptions &Features,
222 bool in_char_string_literal = false) {
223 const char *UcnBegin = ThisTokBuf;
225 // Skip the '\u' char's.
228 if (ThisTokBuf == ThisTokEnd || !isHexDigit(*ThisTokBuf)) {
230 Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
231 diag::err_hex_escape_no_digits) << StringRef(&ThisTokBuf[-1], 1);
234 UcnLen = (ThisTokBuf[-1] == 'u' ? 4 : 8);
235 unsigned short UcnLenSave = UcnLen;
236 for (; ThisTokBuf != ThisTokEnd && UcnLenSave; ++ThisTokBuf, UcnLenSave--) {
237 int CharVal = llvm::hexDigitValue(ThisTokBuf[0]);
238 if (CharVal == -1) break;
242 // If we didn't consume the proper number of digits, there is a problem.
245 Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
246 diag::err_ucn_escape_incomplete);
250 // Check UCN constraints (C99 6.4.3p2) [C++11 lex.charset p2]
251 if ((0xD800 <= UcnVal && UcnVal <= 0xDFFF) || // surrogate codepoints
252 UcnVal > 0x10FFFF) { // maximum legal UTF32 value
254 Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
255 diag::err_ucn_escape_invalid);
259 // C++11 allows UCNs that refer to control characters and basic source
260 // characters inside character and string literals
262 (UcnVal != 0x24 && UcnVal != 0x40 && UcnVal != 0x60)) { // $, @, `
263 bool IsError = (!Features.CPlusPlus11 || !in_char_string_literal);
265 char BasicSCSChar = UcnVal;
266 if (UcnVal >= 0x20 && UcnVal < 0x7f)
267 Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
268 IsError ? diag::err_ucn_escape_basic_scs :
269 diag::warn_cxx98_compat_literal_ucn_escape_basic_scs)
270 << StringRef(&BasicSCSChar, 1);
272 Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
273 IsError ? diag::err_ucn_control_character :
274 diag::warn_cxx98_compat_literal_ucn_control_character);
280 if (!Features.CPlusPlus && !Features.C99 && Diags)
281 Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
282 diag::warn_ucn_not_valid_in_c89_literal);
287 /// MeasureUCNEscape - Determine the number of bytes within the resulting string
288 /// which this UCN will occupy.
289 static int MeasureUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf,
290 const char *ThisTokEnd, unsigned CharByteWidth,
291 const LangOptions &Features, bool &HadError) {
292 // UTF-32: 4 bytes per escape.
293 if (CharByteWidth == 4)
297 unsigned short UcnLen = 0;
300 if (!ProcessUCNEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd, UcnVal,
301 UcnLen, Loc, 0, Features, true)) {
306 // UTF-16: 2 bytes for BMP, 4 bytes otherwise.
307 if (CharByteWidth == 2)
308 return UcnVal <= 0xFFFF ? 2 : 4;
315 if (UcnVal < 0x10000)
320 /// EncodeUCNEscape - Read the Universal Character Name, check constraints and
321 /// convert the UTF32 to UTF8 or UTF16. This is a subroutine of
322 /// StringLiteralParser. When we decide to implement UCN's for identifiers,
323 /// we will likely rework our support for UCN's.
324 static void EncodeUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf,
325 const char *ThisTokEnd,
326 char *&ResultBuf, bool &HadError,
327 FullSourceLoc Loc, unsigned CharByteWidth,
328 DiagnosticsEngine *Diags,
329 const LangOptions &Features) {
330 typedef uint32_t UTF32;
332 unsigned short UcnLen = 0;
333 if (!ProcessUCNEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd, UcnVal, UcnLen,
334 Loc, Diags, Features, true)) {
339 assert((CharByteWidth == 1 || CharByteWidth == 2 || CharByteWidth) &&
340 "only character widths of 1, 2, or 4 bytes supported");
343 assert((UcnLen== 4 || UcnLen== 8) && "only ucn length of 4 or 8 supported");
345 if (CharByteWidth == 4) {
346 // FIXME: Make the type of the result buffer correct instead of
347 // using reinterpret_cast.
348 UTF32 *ResultPtr = reinterpret_cast<UTF32*>(ResultBuf);
354 if (CharByteWidth == 2) {
355 // FIXME: Make the type of the result buffer correct instead of
356 // using reinterpret_cast.
357 UTF16 *ResultPtr = reinterpret_cast<UTF16*>(ResultBuf);
359 if (UcnVal <= (UTF32)0xFFFF) {
367 *ResultPtr = 0xD800 + (UcnVal >> 10);
368 *(ResultPtr+1) = 0xDC00 + (UcnVal & 0x3FF);
373 assert(CharByteWidth == 1 && "UTF-8 encoding is only for 1 byte characters");
375 // Now that we've parsed/checked the UCN, we convert from UTF32->UTF8.
376 // The conversion below was inspired by:
377 // http://www.unicode.org/Public/PROGRAMS/CVTUTF/ConvertUTF.c
378 // First, we determine how many bytes the result will require.
379 typedef uint8_t UTF8;
381 unsigned short bytesToWrite = 0;
382 if (UcnVal < (UTF32)0x80)
384 else if (UcnVal < (UTF32)0x800)
386 else if (UcnVal < (UTF32)0x10000)
391 const unsigned byteMask = 0xBF;
392 const unsigned byteMark = 0x80;
394 // Once the bits are split out into bytes of UTF8, this is a mask OR-ed
395 // into the first byte, depending on how many bytes follow.
396 static const UTF8 firstByteMark[5] = {
397 0x00, 0x00, 0xC0, 0xE0, 0xF0
399 // Finally, we write the bytes into ResultBuf.
400 ResultBuf += bytesToWrite;
401 switch (bytesToWrite) { // note: everything falls through.
402 case 4: *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6;
403 case 3: *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6;
404 case 2: *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6;
405 case 1: *--ResultBuf = (UTF8) (UcnVal | firstByteMark[bytesToWrite]);
407 // Update the buffer.
408 ResultBuf += bytesToWrite;
412 /// integer-constant: [C99 6.4.4.1]
413 /// decimal-constant integer-suffix
414 /// octal-constant integer-suffix
415 /// hexadecimal-constant integer-suffix
416 /// user-defined-integer-literal: [C++11 lex.ext]
417 /// decimal-literal ud-suffix
418 /// octal-literal ud-suffix
419 /// hexadecimal-literal ud-suffix
420 /// decimal-constant:
422 /// decimal-constant digit
425 /// octal-constant octal-digit
426 /// hexadecimal-constant:
427 /// hexadecimal-prefix hexadecimal-digit
428 /// hexadecimal-constant hexadecimal-digit
429 /// hexadecimal-prefix: one of
432 /// unsigned-suffix [long-suffix]
433 /// unsigned-suffix [long-long-suffix]
434 /// long-suffix [unsigned-suffix]
435 /// long-long-suffix [unsigned-sufix]
437 /// 1 2 3 4 5 6 7 8 9
440 /// hexadecimal-digit:
441 /// 0 1 2 3 4 5 6 7 8 9
444 /// unsigned-suffix: one of
446 /// long-suffix: one of
448 /// long-long-suffix: one of
451 /// floating-constant: [C99 6.4.4.2]
452 /// TODO: add rules...
454 NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
455 SourceLocation TokLoc,
457 : PP(PP), ThisTokBegin(TokSpelling.begin()), ThisTokEnd(TokSpelling.end()) {
459 // This routine assumes that the range begin/end matches the regex for integer
460 // and FP constants (specifically, the 'pp-number' regex), and assumes that
461 // the byte at "*end" is both valid and not part of the regex. Because of
462 // this, it doesn't have to check for 'overscan' in various places.
463 assert(!isPreprocessingNumberBody(*ThisTokEnd) && "didn't maximally munch?");
465 s = DigitsBegin = ThisTokBegin;
466 saw_exponent = false;
468 saw_ud_suffix = false;
474 isMicrosoftInteger = false;
477 if (*s == '0') { // parse radix
478 ParseNumberStartingWithZero(TokLoc);
481 } else { // the first digit is non-zero
484 if (s == ThisTokEnd) {
486 } else if (isHexDigit(*s) && !(*s == 'e' || *s == 'E')) {
487 PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin),
488 diag::err_invalid_decimal_digit) << StringRef(s, 1);
491 } else if (*s == '.') {
496 if ((*s == 'e' || *s == 'E')) { // exponent
497 const char *Exponent = s;
500 if (*s == '+' || *s == '-') s++; // sign
501 const char *first_non_digit = SkipDigits(s);
502 if (first_non_digit != s) {
505 PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent - ThisTokBegin),
506 diag::err_exponent_has_no_digits);
515 // Parse the suffix. At this point we can classify whether we have an FP or
517 bool isFPConstant = isFloatingLiteral();
519 // Loop over all of the characters of the suffix. If we see something bad,
520 // we break out of the loop.
521 for (; s != ThisTokEnd; ++s) {
523 case 'f': // FP Suffix for "float"
525 if (!isFPConstant) break; // Error for integer constant.
526 if (isFloat || isLong) break; // FF, LF invalid.
528 continue; // Success.
531 if (isFPConstant) break; // Error for floating constant.
532 if (isUnsigned) break; // Cannot be repeated.
534 continue; // Success.
537 if (isLong || isLongLong) break; // Cannot be repeated.
538 if (isFloat) break; // LF invalid.
540 // Check for long long. The L's need to be adjacent and the same case.
541 if (s+1 != ThisTokEnd && s[1] == s[0]) {
542 if (isFPConstant) break; // long long invalid for floats.
544 ++s; // Eat both of them.
548 continue; // Success.
551 if (PP.getLangOpts().MicrosoftExt) {
552 if (isFPConstant || isLong || isLongLong) break;
554 // Allow i8, i16, i32, i64, and i128.
555 if (s + 1 != ThisTokEnd) {
559 isMicrosoftInteger = true;
562 if (s + 2 == ThisTokEnd) break;
564 s += 3; // i16 suffix
565 isMicrosoftInteger = true;
567 else if (s[2] == '2') {
568 if (s + 3 == ThisTokEnd) break;
570 s += 4; // i128 suffix
571 isMicrosoftInteger = true;
576 if (s + 2 == ThisTokEnd) break;
578 s += 3; // i32 suffix
580 isMicrosoftInteger = true;
584 if (s + 2 == ThisTokEnd) break;
586 s += 3; // i64 suffix
588 isMicrosoftInteger = true;
600 if (isImaginary) break; // Cannot be repeated.
601 PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin),
602 diag::ext_imaginary_constant);
604 continue; // Success.
606 // If we reached here, there was an error or a ud-suffix.
610 if (s != ThisTokEnd) {
611 if (PP.getLangOpts().CPlusPlus11 && s == SuffixBegin && *s == '_') {
612 // We have a ud-suffix! By C++11 [lex.ext]p10, ud-suffixes not starting
613 // with an '_' are ill-formed.
614 saw_ud_suffix = true;
618 // Report an error if there are any.
619 PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, SuffixBegin - ThisTokBegin),
620 isFPConstant ? diag::err_invalid_suffix_float_constant :
621 diag::err_invalid_suffix_integer_constant)
622 << StringRef(SuffixBegin, ThisTokEnd-SuffixBegin);
628 /// ParseNumberStartingWithZero - This method is called when the first character
629 /// of the number is found to be a zero. This means it is either an octal
630 /// number (like '04') or a hex number ('0x123a') a binary number ('0b1010') or
631 /// a floating point number (01239.123e4). Eat the prefix, determining the
633 void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) {
634 assert(s[0] == '0' && "Invalid method call");
637 // Handle a hex number like 0x1234.
638 if ((*s == 'x' || *s == 'X') && (isHexDigit(s[1]) || s[1] == '.')) {
642 s = SkipHexDigits(s);
643 bool noSignificand = (s == DigitsBegin);
644 if (s == ThisTokEnd) {
646 } else if (*s == '.') {
649 const char *floatDigitsBegin = s;
650 s = SkipHexDigits(s);
651 noSignificand &= (floatDigitsBegin == s);
655 PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin),
656 diag::err_hexconstant_requires_digits);
661 // A binary exponent can appear with or with a '.'. If dotted, the
662 // binary exponent is required.
663 if (*s == 'p' || *s == 'P') {
664 const char *Exponent = s;
667 if (*s == '+' || *s == '-') s++; // sign
668 const char *first_non_digit = SkipDigits(s);
669 if (first_non_digit == s) {
670 PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-ThisTokBegin),
671 diag::err_exponent_has_no_digits);
677 if (!PP.getLangOpts().HexFloats)
678 PP.Diag(TokLoc, diag::ext_hexconstant_invalid);
679 } else if (saw_period) {
680 PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
681 diag::err_hexconstant_requires_exponent);
687 // Handle simple binary numbers 0b01010
688 if (*s == 'b' || *s == 'B') {
689 // 0b101010 is a C++1y / GCC extension.
691 PP.getLangOpts().CPlusPlus1y
692 ? diag::warn_cxx11_compat_binary_literal
693 : PP.getLangOpts().CPlusPlus
694 ? diag::ext_binary_literal_cxx1y
695 : diag::ext_binary_literal);
699 s = SkipBinaryDigits(s);
700 if (s == ThisTokEnd) {
702 } else if (isHexDigit(*s)) {
703 PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
704 diag::err_invalid_binary_digit) << StringRef(s, 1);
707 // Other suffixes will be diagnosed by the caller.
711 // For now, the radix is set to 8. If we discover that we have a
712 // floating point constant, the radix will change to 10. Octal floating
713 // point constants are not permitted (only decimal and hexadecimal).
716 s = SkipOctalDigits(s);
718 return; // Done, simple octal number like 01234
720 // If we have some other non-octal digit that *is* a decimal digit, see if
721 // this is part of a floating point number like 094.123 or 09e1.
723 const char *EndDecimal = SkipDigits(s);
724 if (EndDecimal[0] == '.' || EndDecimal[0] == 'e' || EndDecimal[0] == 'E') {
730 // If we have a hex digit other than 'e' (which denotes a FP exponent) then
731 // the code is using an incorrect base.
732 if (isHexDigit(*s) && *s != 'e' && *s != 'E') {
733 PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
734 diag::err_invalid_octal_digit) << StringRef(s, 1);
743 s = SkipDigits(s); // Skip suffix.
745 if (*s == 'e' || *s == 'E') { // exponent
746 const char *Exponent = s;
750 if (*s == '+' || *s == '-') s++; // sign
751 const char *first_non_digit = SkipDigits(s);
752 if (first_non_digit != s) {
755 PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-ThisTokBegin),
756 diag::err_exponent_has_no_digits);
763 static bool alwaysFitsInto64Bits(unsigned Radix, unsigned NumDigits) {
766 return NumDigits <= 64;
768 return NumDigits <= 64 / 3; // Digits are groups of 3 bits.
770 return NumDigits <= 19; // floor(log10(2^64))
772 return NumDigits <= 64 / 4; // Digits are groups of 4 bits.
774 llvm_unreachable("impossible Radix");
778 /// GetIntegerValue - Convert this numeric literal value to an APInt that
779 /// matches Val's input width. If there is an overflow, set Val to the low bits
780 /// of the result and return true. Otherwise, return false.
781 bool NumericLiteralParser::GetIntegerValue(llvm::APInt &Val) {
782 // Fast path: Compute a conservative bound on the maximum number of
783 // bits per digit in this radix. If we can't possibly overflow a
784 // uint64 based on that bound then do the simple conversion to
785 // integer. This avoids the expensive overflow checking below, and
786 // handles the common cases that matter (small decimal integers and
787 // hex/octal values which don't overflow).
788 const unsigned NumDigits = SuffixBegin - DigitsBegin;
789 if (alwaysFitsInto64Bits(radix, NumDigits)) {
791 for (const char *Ptr = DigitsBegin; Ptr != SuffixBegin; ++Ptr)
792 N = N * radix + llvm::hexDigitValue(*Ptr);
794 // This will truncate the value to Val's input width. Simply check
795 // for overflow by comparing.
797 return Val.getZExtValue() != N;
801 const char *Ptr = DigitsBegin;
803 llvm::APInt RadixVal(Val.getBitWidth(), radix);
804 llvm::APInt CharVal(Val.getBitWidth(), 0);
805 llvm::APInt OldVal = Val;
807 bool OverflowOccurred = false;
808 while (Ptr < SuffixBegin) {
809 unsigned C = llvm::hexDigitValue(*Ptr++);
811 // If this letter is out of bound for this radix, reject it.
812 assert(C < radix && "NumericLiteralParser ctor should have rejected this");
816 // Add the digit to the value in the appropriate radix. If adding in digits
817 // made the value smaller, then this overflowed.
820 // Multiply by radix, did overflow occur on the multiply?
822 OverflowOccurred |= Val.udiv(RadixVal) != OldVal;
824 // Add value, did overflow occur on the value?
825 // (a + b) ult b <=> overflow
827 OverflowOccurred |= Val.ult(CharVal);
829 return OverflowOccurred;
832 llvm::APFloat::opStatus
833 NumericLiteralParser::GetFloatValue(llvm::APFloat &Result) {
836 unsigned n = std::min(SuffixBegin - ThisTokBegin, ThisTokEnd - ThisTokBegin);
837 return Result.convertFromString(StringRef(ThisTokBegin, n),
838 APFloat::rmNearestTiesToEven);
843 /// user-defined-character-literal: [C++11 lex.ext]
844 /// character-literal ud-suffix
847 /// character-literal: [C++11 lex.ccon]
848 /// ' c-char-sequence '
849 /// u' c-char-sequence '
850 /// U' c-char-sequence '
851 /// L' c-char-sequence '
854 /// c-char-sequence c-char
856 /// any member of the source character set except the single-quote ',
857 /// backslash \, or new-line character
859 /// universal-character-name
861 /// simple-escape-sequence
862 /// octal-escape-sequence
863 /// hexadecimal-escape-sequence
864 /// simple-escape-sequence:
865 /// one of \' \" \? \\ \a \b \f \n \r \t \v
866 /// octal-escape-sequence:
868 /// \ octal-digit octal-digit
869 /// \ octal-digit octal-digit octal-digit
870 /// hexadecimal-escape-sequence:
871 /// \x hexadecimal-digit
872 /// hexadecimal-escape-sequence hexadecimal-digit
873 /// universal-character-name: [C++11 lex.charset]
875 /// \U hex-quad hex-quad
877 /// hex-digit hex-digit hex-digit hex-digit
880 CharLiteralParser::CharLiteralParser(const char *begin, const char *end,
881 SourceLocation Loc, Preprocessor &PP,
882 tok::TokenKind kind) {
883 // At this point we know that the character matches the regex "(L|u|U)?'.*'".
888 const char *TokBegin = begin;
890 // Skip over wide character determinant.
891 if (Kind != tok::char_constant) {
895 // Skip over the entry quote.
896 assert(begin[0] == '\'' && "Invalid token lexed");
899 // Remove an optional ud-suffix.
900 if (end[-1] != '\'') {
901 const char *UDSuffixEnd = end;
904 } while (end[-1] != '\'');
905 UDSuffixBuf.assign(end, UDSuffixEnd);
906 UDSuffixOffset = end - TokBegin;
909 // Trim the ending quote.
910 assert(end != begin && "Invalid token lexed");
913 // FIXME: The "Value" is an uint64_t so we can handle char literals of
915 // FIXME: This extensively assumes that 'char' is 8-bits.
916 assert(PP.getTargetInfo().getCharWidth() == 8 &&
917 "Assumes char is 8 bits");
918 assert(PP.getTargetInfo().getIntWidth() <= 64 &&
919 (PP.getTargetInfo().getIntWidth() & 7) == 0 &&
920 "Assumes sizeof(int) on target is <= 64 and a multiple of char");
921 assert(PP.getTargetInfo().getWCharWidth() <= 64 &&
922 "Assumes sizeof(wchar) on target is <= 64");
924 SmallVector<uint32_t,4> codepoint_buffer;
925 codepoint_buffer.resize(end-begin);
926 uint32_t *buffer_begin = &codepoint_buffer.front();
927 uint32_t *buffer_end = buffer_begin + codepoint_buffer.size();
929 // Unicode escapes representing characters that cannot be correctly
930 // represented in a single code unit are disallowed in character literals
931 // by this implementation.
932 uint32_t largest_character_for_kind;
933 if (tok::wide_char_constant == Kind) {
934 largest_character_for_kind = 0xFFFFFFFFu >> (32-PP.getTargetInfo().getWCharWidth());
935 } else if (tok::utf16_char_constant == Kind) {
936 largest_character_for_kind = 0xFFFF;
937 } else if (tok::utf32_char_constant == Kind) {
938 largest_character_for_kind = 0x10FFFF;
940 largest_character_for_kind = 0x7Fu;
944 // Is this a span of non-escape characters?
945 if (begin[0] != '\\') {
946 char const *start = begin;
949 } while (begin != end && *begin != '\\');
951 char const *tmp_in_start = start;
952 uint32_t *tmp_out_start = buffer_begin;
953 ConversionResult res =
954 ConvertUTF8toUTF32(reinterpret_cast<UTF8 const **>(&start),
955 reinterpret_cast<UTF8 const *>(begin),
956 &buffer_begin,buffer_end,strictConversion);
957 if (res!=conversionOK) {
958 // If we see bad encoding for unprefixed character literals, warn and
959 // simply copy the byte values, for compatibility with gcc and
960 // older versions of clang.
961 bool NoErrorOnBadEncoding = isAscii();
962 unsigned Msg = diag::err_bad_character_encoding;
963 if (NoErrorOnBadEncoding)
964 Msg = diag::warn_bad_character_encoding;
966 if (NoErrorOnBadEncoding) {
967 start = tmp_in_start;
968 buffer_begin = tmp_out_start;
969 for ( ; start != begin; ++start, ++buffer_begin)
970 *buffer_begin = static_cast<uint8_t>(*start);
975 for (; tmp_out_start <buffer_begin; ++tmp_out_start) {
976 if (*tmp_out_start > largest_character_for_kind) {
978 PP.Diag(Loc, diag::err_character_too_large);
985 // Is this a Universal Character Name excape?
986 if (begin[1] == 'u' || begin[1] == 'U') {
987 unsigned short UcnLen = 0;
988 if (!ProcessUCNEscape(TokBegin, begin, end, *buffer_begin, UcnLen,
989 FullSourceLoc(Loc, PP.getSourceManager()),
990 &PP.getDiagnostics(), PP.getLangOpts(),
994 } else if (*buffer_begin > largest_character_for_kind) {
996 PP.Diag(Loc, diag::err_character_too_large);
1002 unsigned CharWidth = getCharWidth(Kind, PP.getTargetInfo());
1004 ProcessCharEscape(TokBegin, begin, end, HadError,
1005 FullSourceLoc(Loc,PP.getSourceManager()),
1006 CharWidth, &PP.getDiagnostics(), PP.getLangOpts());
1007 *buffer_begin++ = result;
1010 unsigned NumCharsSoFar = buffer_begin-&codepoint_buffer.front();
1012 if (NumCharsSoFar > 1) {
1014 PP.Diag(Loc, diag::warn_extraneous_char_constant);
1015 else if (isAscii() && NumCharsSoFar == 4)
1016 PP.Diag(Loc, diag::ext_four_char_character_literal);
1018 PP.Diag(Loc, diag::ext_multichar_character_literal);
1020 PP.Diag(Loc, diag::err_multichar_utf_character_literal);
1023 IsMultiChar = false;
1025 llvm::APInt LitVal(PP.getTargetInfo().getIntWidth(), 0);
1027 // Narrow character literals act as though their value is concatenated
1028 // in this implementation, but warn on overflow.
1029 bool multi_char_too_long = false;
1030 if (isAscii() && isMultiChar()) {
1032 for (size_t i=0;i<NumCharsSoFar;++i) {
1033 // check for enough leading zeros to shift into
1034 multi_char_too_long |= (LitVal.countLeadingZeros() < 8);
1036 LitVal = LitVal + (codepoint_buffer[i] & 0xFF);
1038 } else if (NumCharsSoFar > 0) {
1039 // otherwise just take the last character
1040 LitVal = buffer_begin[-1];
1043 if (!HadError && multi_char_too_long) {
1044 PP.Diag(Loc,diag::warn_char_constant_too_large);
1047 // Transfer the value from APInt to uint64_t
1048 Value = LitVal.getZExtValue();
1050 // If this is a single narrow character, sign extend it (e.g. '\xFF' is "-1")
1051 // if 'char' is signed for this target (C99 6.4.4.4p10). Note that multiple
1052 // character constants are not sign extended in the this implementation:
1053 // '\xFF\xFF' = 65536 and '\x0\xFF' = 255, which matches GCC.
1054 if (isAscii() && NumCharsSoFar == 1 && (Value & 128) &&
1055 PP.getLangOpts().CharIsSigned)
1056 Value = (signed char)Value;
1060 /// string-literal: [C++0x lex.string]
1061 /// encoding-prefix " [s-char-sequence] "
1062 /// encoding-prefix R raw-string
1063 /// encoding-prefix:
1068 /// s-char-sequence:
1070 /// s-char-sequence s-char
1072 /// any member of the source character set except the double-quote ",
1073 /// backslash \, or new-line character
1075 /// universal-character-name
1077 /// " d-char-sequence ( r-char-sequence ) d-char-sequence "
1078 /// r-char-sequence:
1080 /// r-char-sequence r-char
1082 /// any member of the source character set, except a right parenthesis )
1083 /// followed by the initial d-char-sequence (which may be empty)
1084 /// followed by a double quote ".
1085 /// d-char-sequence:
1087 /// d-char-sequence d-char
1089 /// any member of the basic source character set except:
1090 /// space, the left parenthesis (, the right parenthesis ),
1091 /// the backslash \, and the control characters representing horizontal
1092 /// tab, vertical tab, form feed, and newline.
1093 /// escape-sequence: [C++0x lex.ccon]
1094 /// simple-escape-sequence
1095 /// octal-escape-sequence
1096 /// hexadecimal-escape-sequence
1097 /// simple-escape-sequence:
1098 /// one of \' \" \? \\ \a \b \f \n \r \t \v
1099 /// octal-escape-sequence:
1101 /// \ octal-digit octal-digit
1102 /// \ octal-digit octal-digit octal-digit
1103 /// hexadecimal-escape-sequence:
1104 /// \x hexadecimal-digit
1105 /// hexadecimal-escape-sequence hexadecimal-digit
1106 /// universal-character-name:
1108 /// \U hex-quad hex-quad
1110 /// hex-digit hex-digit hex-digit hex-digit
1113 StringLiteralParser::
1114 StringLiteralParser(const Token *StringToks, unsigned NumStringToks,
1115 Preprocessor &PP, bool Complain)
1116 : SM(PP.getSourceManager()), Features(PP.getLangOpts()),
1117 Target(PP.getTargetInfo()), Diags(Complain ? &PP.getDiagnostics() : 0),
1118 MaxTokenLength(0), SizeBound(0), CharByteWidth(0), Kind(tok::unknown),
1119 ResultPtr(ResultBuf.data()), hadError(false), Pascal(false) {
1120 init(StringToks, NumStringToks);
1123 void StringLiteralParser::init(const Token *StringToks, unsigned NumStringToks){
1124 // The literal token may have come from an invalid source location (e.g. due
1125 // to a PCH error), in which case the token length will be 0.
1126 if (NumStringToks == 0 || StringToks[0].getLength() < 2)
1127 return DiagnoseLexingError(SourceLocation());
1129 // Scan all of the string portions, remember the max individual token length,
1130 // computing a bound on the concatenated string length, and see whether any
1131 // piece is a wide-string. If any of the string portions is a wide-string
1132 // literal, the result is a wide-string literal [C99 6.4.5p4].
1133 assert(NumStringToks && "expected at least one token");
1134 MaxTokenLength = StringToks[0].getLength();
1135 assert(StringToks[0].getLength() >= 2 && "literal token is invalid!");
1136 SizeBound = StringToks[0].getLength()-2; // -2 for "".
1137 Kind = StringToks[0].getKind();
1141 // Implement Translation Phase #6: concatenation of string literals
1142 /// (C99 5.1.1.2p1). The common case is only one string fragment.
1143 for (unsigned i = 1; i != NumStringToks; ++i) {
1144 if (StringToks[i].getLength() < 2)
1145 return DiagnoseLexingError(StringToks[i].getLocation());
1147 // The string could be shorter than this if it needs cleaning, but this is a
1148 // reasonable bound, which is all we need.
1149 assert(StringToks[i].getLength() >= 2 && "literal token is invalid!");
1150 SizeBound += StringToks[i].getLength()-2; // -2 for "".
1152 // Remember maximum string piece length.
1153 if (StringToks[i].getLength() > MaxTokenLength)
1154 MaxTokenLength = StringToks[i].getLength();
1156 // Remember if we see any wide or utf-8/16/32 strings.
1157 // Also check for illegal concatenations.
1158 if (StringToks[i].isNot(Kind) && StringToks[i].isNot(tok::string_literal)) {
1160 Kind = StringToks[i].getKind();
1163 Diags->Report(StringToks[i].getLocation(),
1164 diag::err_unsupported_string_concat);
1170 // Include space for the null terminator.
1173 // TODO: K&R warning: "traditional C rejects string constant concatenation"
1175 // Get the width in bytes of char/wchar_t/char16_t/char32_t
1176 CharByteWidth = getCharWidth(Kind, Target);
1177 assert((CharByteWidth & 7) == 0 && "Assumes character size is byte multiple");
1180 // The output buffer size needs to be large enough to hold wide characters.
1181 // This is a worst-case assumption which basically corresponds to L"" "long".
1182 SizeBound *= CharByteWidth;
1184 // Size the temporary buffer to hold the result string data.
1185 ResultBuf.resize(SizeBound);
1187 // Likewise, but for each string piece.
1188 SmallString<512> TokenBuf;
1189 TokenBuf.resize(MaxTokenLength);
1191 // Loop over all the strings, getting their spelling, and expanding them to
1192 // wide strings as appropriate.
1193 ResultPtr = &ResultBuf[0]; // Next byte to fill in.
1197 SourceLocation UDSuffixTokLoc;
1199 for (unsigned i = 0, e = NumStringToks; i != e; ++i) {
1200 const char *ThisTokBuf = &TokenBuf[0];
1201 // Get the spelling of the token, which eliminates trigraphs, etc. We know
1202 // that ThisTokBuf points to a buffer that is big enough for the whole token
1203 // and 'spelled' tokens can only shrink.
1204 bool StringInvalid = false;
1205 unsigned ThisTokLen =
1206 Lexer::getSpelling(StringToks[i], ThisTokBuf, SM, Features,
1209 return DiagnoseLexingError(StringToks[i].getLocation());
1211 const char *ThisTokBegin = ThisTokBuf;
1212 const char *ThisTokEnd = ThisTokBuf+ThisTokLen;
1214 // Remove an optional ud-suffix.
1215 if (ThisTokEnd[-1] != '"') {
1216 const char *UDSuffixEnd = ThisTokEnd;
1219 } while (ThisTokEnd[-1] != '"');
1221 StringRef UDSuffix(ThisTokEnd, UDSuffixEnd - ThisTokEnd);
1223 if (UDSuffixBuf.empty()) {
1224 UDSuffixBuf.assign(UDSuffix);
1226 UDSuffixOffset = ThisTokEnd - ThisTokBuf;
1227 UDSuffixTokLoc = StringToks[i].getLocation();
1228 } else if (!UDSuffixBuf.equals(UDSuffix)) {
1229 // C++11 [lex.ext]p8: At the end of phase 6, if a string literal is the
1230 // result of a concatenation involving at least one user-defined-string-
1231 // literal, all the participating user-defined-string-literals shall
1232 // have the same ud-suffix.
1234 SourceLocation TokLoc = StringToks[i].getLocation();
1235 Diags->Report(TokLoc, diag::err_string_concat_mixed_suffix)
1236 << UDSuffixBuf << UDSuffix
1237 << SourceRange(UDSuffixTokLoc, UDSuffixTokLoc)
1238 << SourceRange(TokLoc, TokLoc);
1244 // Strip the end quote.
1247 // TODO: Input character set mapping support.
1249 // Skip marker for wide or unicode strings.
1250 if (ThisTokBuf[0] == 'L' || ThisTokBuf[0] == 'u' || ThisTokBuf[0] == 'U') {
1252 // Skip 8 of u8 marker for utf8 strings.
1253 if (ThisTokBuf[0] == '8')
1257 // Check for raw string
1258 if (ThisTokBuf[0] == 'R') {
1259 ThisTokBuf += 2; // skip R"
1261 const char *Prefix = ThisTokBuf;
1262 while (ThisTokBuf[0] != '(')
1264 ++ThisTokBuf; // skip '('
1266 // Remove same number of characters from the end
1267 ThisTokEnd -= ThisTokBuf - Prefix;
1268 assert(ThisTokEnd >= ThisTokBuf && "malformed raw string literal");
1270 // Copy the string over
1271 if (CopyStringFragment(StringToks[i], ThisTokBegin,
1272 StringRef(ThisTokBuf, ThisTokEnd - ThisTokBuf)))
1275 if (ThisTokBuf[0] != '"') {
1276 // The file may have come from PCH and then changed after loading the
1277 // PCH; Fail gracefully.
1278 return DiagnoseLexingError(StringToks[i].getLocation());
1280 ++ThisTokBuf; // skip "
1282 // Check if this is a pascal string
1283 if (Features.PascalStrings && ThisTokBuf + 1 != ThisTokEnd &&
1284 ThisTokBuf[0] == '\\' && ThisTokBuf[1] == 'p') {
1286 // If the \p sequence is found in the first token, we have a pascal string
1287 // Otherwise, if we already have a pascal string, ignore the first \p
1295 while (ThisTokBuf != ThisTokEnd) {
1296 // Is this a span of non-escape characters?
1297 if (ThisTokBuf[0] != '\\') {
1298 const char *InStart = ThisTokBuf;
1301 } while (ThisTokBuf != ThisTokEnd && ThisTokBuf[0] != '\\');
1303 // Copy the character span over.
1304 if (CopyStringFragment(StringToks[i], ThisTokBegin,
1305 StringRef(InStart, ThisTokBuf - InStart)))
1309 // Is this a Universal Character Name escape?
1310 if (ThisTokBuf[1] == 'u' || ThisTokBuf[1] == 'U') {
1311 EncodeUCNEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd,
1312 ResultPtr, hadError,
1313 FullSourceLoc(StringToks[i].getLocation(), SM),
1314 CharByteWidth, Diags, Features);
1317 // Otherwise, this is a non-UCN escape character. Process it.
1318 unsigned ResultChar =
1319 ProcessCharEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd, hadError,
1320 FullSourceLoc(StringToks[i].getLocation(), SM),
1321 CharByteWidth*8, Diags, Features);
1323 if (CharByteWidth == 4) {
1324 // FIXME: Make the type of the result buffer correct instead of
1325 // using reinterpret_cast.
1326 UTF32 *ResultWidePtr = reinterpret_cast<UTF32*>(ResultPtr);
1327 *ResultWidePtr = ResultChar;
1329 } else if (CharByteWidth == 2) {
1330 // FIXME: Make the type of the result buffer correct instead of
1331 // using reinterpret_cast.
1332 UTF16 *ResultWidePtr = reinterpret_cast<UTF16*>(ResultPtr);
1333 *ResultWidePtr = ResultChar & 0xFFFF;
1336 assert(CharByteWidth == 1 && "Unexpected char width");
1337 *ResultPtr++ = ResultChar & 0xFF;
1344 if (CharByteWidth == 4) {
1345 // FIXME: Make the type of the result buffer correct instead of
1346 // using reinterpret_cast.
1347 UTF32 *ResultWidePtr = reinterpret_cast<UTF32*>(ResultBuf.data());
1348 ResultWidePtr[0] = GetNumStringChars() - 1;
1349 } else if (CharByteWidth == 2) {
1350 // FIXME: Make the type of the result buffer correct instead of
1351 // using reinterpret_cast.
1352 UTF16 *ResultWidePtr = reinterpret_cast<UTF16*>(ResultBuf.data());
1353 ResultWidePtr[0] = GetNumStringChars() - 1;
1355 assert(CharByteWidth == 1 && "Unexpected char width");
1356 ResultBuf[0] = GetNumStringChars() - 1;
1359 // Verify that pascal strings aren't too large.
1360 if (GetStringLength() > 256) {
1362 Diags->Report(StringToks[0].getLocation(),
1363 diag::err_pascal_string_too_long)
1364 << SourceRange(StringToks[0].getLocation(),
1365 StringToks[NumStringToks-1].getLocation());
1370 // Complain if this string literal has too many characters.
1371 unsigned MaxChars = Features.CPlusPlus? 65536 : Features.C99 ? 4095 : 509;
1373 if (GetNumStringChars() > MaxChars)
1374 Diags->Report(StringToks[0].getLocation(),
1375 diag::ext_string_too_long)
1376 << GetNumStringChars() << MaxChars
1377 << (Features.CPlusPlus ? 2 : Features.C99 ? 1 : 0)
1378 << SourceRange(StringToks[0].getLocation(),
1379 StringToks[NumStringToks-1].getLocation());
1383 static const char *resyncUTF8(const char *Err, const char *End) {
1386 End = Err + std::min<unsigned>(getNumBytesForUTF8(*Err), End-Err);
1387 while (++Err != End && (*Err & 0xC0) == 0x80)
1392 /// \brief This function copies from Fragment, which is a sequence of bytes
1393 /// within Tok's contents (which begin at TokBegin) into ResultPtr.
1394 /// Performs widening for multi-byte characters.
1395 bool StringLiteralParser::CopyStringFragment(const Token &Tok,
1396 const char *TokBegin,
1397 StringRef Fragment) {
1398 const UTF8 *ErrorPtrTmp;
1399 if (ConvertUTF8toWide(CharByteWidth, Fragment, ResultPtr, ErrorPtrTmp))
1402 // If we see bad encoding for unprefixed string literals, warn and
1403 // simply copy the byte values, for compatibility with gcc and older
1404 // versions of clang.
1405 bool NoErrorOnBadEncoding = isAscii();
1406 if (NoErrorOnBadEncoding) {
1407 memcpy(ResultPtr, Fragment.data(), Fragment.size());
1408 ResultPtr += Fragment.size();
1412 const char *ErrorPtr = reinterpret_cast<const char *>(ErrorPtrTmp);
1414 FullSourceLoc SourceLoc(Tok.getLocation(), SM);
1415 const DiagnosticBuilder &Builder =
1416 Diag(Diags, Features, SourceLoc, TokBegin,
1417 ErrorPtr, resyncUTF8(ErrorPtr, Fragment.end()),
1418 NoErrorOnBadEncoding ? diag::warn_bad_string_encoding
1419 : diag::err_bad_string_encoding);
1421 const char *NextStart = resyncUTF8(ErrorPtr, Fragment.end());
1422 StringRef NextFragment(NextStart, Fragment.end()-NextStart);
1424 // Decode into a dummy buffer.
1425 SmallString<512> Dummy;
1426 Dummy.reserve(Fragment.size() * CharByteWidth);
1427 char *Ptr = Dummy.data();
1429 while (!Builder.hasMaxRanges() &&
1430 !ConvertUTF8toWide(CharByteWidth, NextFragment, Ptr, ErrorPtrTmp)) {
1431 const char *ErrorPtr = reinterpret_cast<const char *>(ErrorPtrTmp);
1432 NextStart = resyncUTF8(ErrorPtr, Fragment.end());
1433 Builder << MakeCharSourceRange(Features, SourceLoc, TokBegin,
1434 ErrorPtr, NextStart);
1435 NextFragment = StringRef(NextStart, Fragment.end()-NextStart);
1438 return !NoErrorOnBadEncoding;
1441 void StringLiteralParser::DiagnoseLexingError(SourceLocation Loc) {
1444 Diags->Report(Loc, diag::err_lexing_string);
1447 /// getOffsetOfStringByte - This function returns the offset of the
1448 /// specified byte of the string data represented by Token. This handles
1449 /// advancing over escape sequences in the string.
1450 unsigned StringLiteralParser::getOffsetOfStringByte(const Token &Tok,
1451 unsigned ByteNo) const {
1452 // Get the spelling of the token.
1453 SmallString<32> SpellingBuffer;
1454 SpellingBuffer.resize(Tok.getLength());
1456 bool StringInvalid = false;
1457 const char *SpellingPtr = &SpellingBuffer[0];
1458 unsigned TokLen = Lexer::getSpelling(Tok, SpellingPtr, SM, Features,
1463 const char *SpellingStart = SpellingPtr;
1464 const char *SpellingEnd = SpellingPtr+TokLen;
1466 // Handle UTF-8 strings just like narrow strings.
1467 if (SpellingPtr[0] == 'u' && SpellingPtr[1] == '8')
1470 assert(SpellingPtr[0] != 'L' && SpellingPtr[0] != 'u' &&
1471 SpellingPtr[0] != 'U' && "Doesn't handle wide or utf strings yet");
1473 // For raw string literals, this is easy.
1474 if (SpellingPtr[0] == 'R') {
1475 assert(SpellingPtr[1] == '"' && "Should be a raw string literal!");
1478 while (*SpellingPtr != '(') {
1480 assert(SpellingPtr < SpellingEnd && "Missing ( for raw string literal");
1484 return SpellingPtr - SpellingStart + ByteNo;
1487 // Skip over the leading quote
1488 assert(SpellingPtr[0] == '"' && "Should be a string literal!");
1491 // Skip over bytes until we find the offset we're looking for.
1493 assert(SpellingPtr < SpellingEnd && "Didn't find byte offset!");
1495 // Step over non-escapes simply.
1496 if (*SpellingPtr != '\\') {
1502 // Otherwise, this is an escape character. Advance over it.
1503 bool HadError = false;
1504 if (SpellingPtr[1] == 'u' || SpellingPtr[1] == 'U') {
1505 const char *EscapePtr = SpellingPtr;
1506 unsigned Len = MeasureUCNEscape(SpellingStart, SpellingPtr, SpellingEnd,
1507 1, Features, HadError);
1509 // ByteNo is somewhere within the escape sequence.
1510 SpellingPtr = EscapePtr;
1515 ProcessCharEscape(SpellingStart, SpellingPtr, SpellingEnd, HadError,
1516 FullSourceLoc(Tok.getLocation(), SM),
1517 CharByteWidth*8, Diags, Features);
1520 assert(!HadError && "This method isn't valid on erroneous strings");
1523 return SpellingPtr-SpellingStart;