clang  3.7.0
LiteralSupport.cpp
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1 //===--- LiteralSupport.cpp - Code to parse and process literals ----------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the NumericLiteralParser, CharLiteralParser, and
11 // StringLiteralParser interfaces.
12 //
13 //===----------------------------------------------------------------------===//
14 
16 #include "clang/Basic/CharInfo.h"
17 #include "clang/Basic/TargetInfo.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"
23 
24 using namespace clang;
25 
26 static unsigned getCharWidth(tok::TokenKind kind, const TargetInfo &Target) {
27  switch (kind) {
28  default: llvm_unreachable("Unknown token type!");
29  case tok::char_constant:
30  case tok::string_literal:
31  case tok::utf8_char_constant:
32  case tok::utf8_string_literal:
33  return Target.getCharWidth();
34  case tok::wide_char_constant:
35  case tok::wide_string_literal:
36  return Target.getWCharWidth();
37  case tok::utf16_char_constant:
38  case tok::utf16_string_literal:
39  return Target.getChar16Width();
40  case tok::utf32_char_constant:
41  case tok::utf32_string_literal:
42  return Target.getChar32Width();
43  }
44 }
45 
47  FullSourceLoc TokLoc,
48  const char *TokBegin,
49  const char *TokRangeBegin,
50  const char *TokRangeEnd) {
51  SourceLocation Begin =
52  Lexer::AdvanceToTokenCharacter(TokLoc, TokRangeBegin - TokBegin,
53  TokLoc.getManager(), Features);
55  Lexer::AdvanceToTokenCharacter(Begin, TokRangeEnd - TokRangeBegin,
56  TokLoc.getManager(), Features);
57  return CharSourceRange::getCharRange(Begin, End);
58 }
59 
60 /// \brief Produce a diagnostic highlighting some portion of a literal.
61 ///
62 /// Emits the diagnostic \p DiagID, highlighting the range of characters from
63 /// \p TokRangeBegin (inclusive) to \p TokRangeEnd (exclusive), which must be
64 /// a substring of a spelling buffer for the token beginning at \p TokBegin.
66  const LangOptions &Features, FullSourceLoc TokLoc,
67  const char *TokBegin, const char *TokRangeBegin,
68  const char *TokRangeEnd, unsigned DiagID) {
69  SourceLocation Begin =
70  Lexer::AdvanceToTokenCharacter(TokLoc, TokRangeBegin - TokBegin,
71  TokLoc.getManager(), Features);
72  return Diags->Report(Begin, DiagID) <<
73  MakeCharSourceRange(Features, TokLoc, TokBegin, TokRangeBegin, TokRangeEnd);
74 }
75 
76 /// ProcessCharEscape - Parse a standard C escape sequence, which can occur in
77 /// either a character or a string literal.
78 static unsigned ProcessCharEscape(const char *ThisTokBegin,
79  const char *&ThisTokBuf,
80  const char *ThisTokEnd, bool &HadError,
81  FullSourceLoc Loc, unsigned CharWidth,
82  DiagnosticsEngine *Diags,
83  const LangOptions &Features) {
84  const char *EscapeBegin = ThisTokBuf;
85 
86  // Skip the '\' char.
87  ++ThisTokBuf;
88 
89  // We know that this character can't be off the end of the buffer, because
90  // that would have been \", which would not have been the end of string.
91  unsigned ResultChar = *ThisTokBuf++;
92  switch (ResultChar) {
93  // These map to themselves.
94  case '\\': case '\'': case '"': case '?': break;
95 
96  // These have fixed mappings.
97  case 'a':
98  // TODO: K&R: the meaning of '\\a' is different in traditional C
99  ResultChar = 7;
100  break;
101  case 'b':
102  ResultChar = 8;
103  break;
104  case 'e':
105  if (Diags)
106  Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
107  diag::ext_nonstandard_escape) << "e";
108  ResultChar = 27;
109  break;
110  case 'E':
111  if (Diags)
112  Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
113  diag::ext_nonstandard_escape) << "E";
114  ResultChar = 27;
115  break;
116  case 'f':
117  ResultChar = 12;
118  break;
119  case 'n':
120  ResultChar = 10;
121  break;
122  case 'r':
123  ResultChar = 13;
124  break;
125  case 't':
126  ResultChar = 9;
127  break;
128  case 'v':
129  ResultChar = 11;
130  break;
131  case 'x': { // Hex escape.
132  ResultChar = 0;
133  if (ThisTokBuf == ThisTokEnd || !isHexDigit(*ThisTokBuf)) {
134  if (Diags)
135  Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
136  diag::err_hex_escape_no_digits) << "x";
137  HadError = 1;
138  break;
139  }
140 
141  // Hex escapes are a maximal series of hex digits.
142  bool Overflow = false;
143  for (; ThisTokBuf != ThisTokEnd; ++ThisTokBuf) {
144  int CharVal = llvm::hexDigitValue(ThisTokBuf[0]);
145  if (CharVal == -1) break;
146  // About to shift out a digit?
147  if (ResultChar & 0xF0000000)
148  Overflow = true;
149  ResultChar <<= 4;
150  ResultChar |= CharVal;
151  }
152 
153  // See if any bits will be truncated when evaluated as a character.
154  if (CharWidth != 32 && (ResultChar >> CharWidth) != 0) {
155  Overflow = true;
156  ResultChar &= ~0U >> (32-CharWidth);
157  }
158 
159  // Check for overflow.
160  if (Overflow && Diags) // Too many digits to fit in
161  Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
162  diag::err_hex_escape_too_large);
163  break;
164  }
165  case '0': case '1': case '2': case '3':
166  case '4': case '5': case '6': case '7': {
167  // Octal escapes.
168  --ThisTokBuf;
169  ResultChar = 0;
170 
171  // Octal escapes are a series of octal digits with maximum length 3.
172  // "\0123" is a two digit sequence equal to "\012" "3".
173  unsigned NumDigits = 0;
174  do {
175  ResultChar <<= 3;
176  ResultChar |= *ThisTokBuf++ - '0';
177  ++NumDigits;
178  } while (ThisTokBuf != ThisTokEnd && NumDigits < 3 &&
179  ThisTokBuf[0] >= '0' && ThisTokBuf[0] <= '7');
180 
181  // Check for overflow. Reject '\777', but not L'\777'.
182  if (CharWidth != 32 && (ResultChar >> CharWidth) != 0) {
183  if (Diags)
184  Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
185  diag::err_octal_escape_too_large);
186  ResultChar &= ~0U >> (32-CharWidth);
187  }
188  break;
189  }
190 
191  // Otherwise, these are not valid escapes.
192  case '(': case '{': case '[': case '%':
193  // GCC accepts these as extensions. We warn about them as such though.
194  if (Diags)
195  Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
196  diag::ext_nonstandard_escape)
197  << std::string(1, ResultChar);
198  break;
199  default:
200  if (!Diags)
201  break;
202 
203  if (isPrintable(ResultChar))
204  Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
205  diag::ext_unknown_escape)
206  << std::string(1, ResultChar);
207  else
208  Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
209  diag::ext_unknown_escape)
210  << "x" + llvm::utohexstr(ResultChar);
211  break;
212  }
213 
214  return ResultChar;
215 }
216 
217 static void appendCodePoint(unsigned Codepoint,
219  char ResultBuf[4];
220  char *ResultPtr = ResultBuf;
221  bool Res = llvm::ConvertCodePointToUTF8(Codepoint, ResultPtr);
222  (void)Res;
223  assert(Res && "Unexpected conversion failure");
224  Str.append(ResultBuf, ResultPtr);
225 }
226 
228  for (StringRef::iterator I = Input.begin(), E = Input.end(); I != E; ++I) {
229  if (*I != '\\') {
230  Buf.push_back(*I);
231  continue;
232  }
233 
234  ++I;
235  assert(*I == 'u' || *I == 'U');
236 
237  unsigned NumHexDigits;
238  if (*I == 'u')
239  NumHexDigits = 4;
240  else
241  NumHexDigits = 8;
242 
243  assert(I + NumHexDigits <= E);
244 
245  uint32_t CodePoint = 0;
246  for (++I; NumHexDigits != 0; ++I, --NumHexDigits) {
247  unsigned Value = llvm::hexDigitValue(*I);
248  assert(Value != -1U);
249 
250  CodePoint <<= 4;
251  CodePoint += Value;
252  }
253 
254  appendCodePoint(CodePoint, Buf);
255  --I;
256  }
257 }
258 
259 /// ProcessUCNEscape - Read the Universal Character Name, check constraints and
260 /// return the UTF32.
261 static bool ProcessUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf,
262  const char *ThisTokEnd,
263  uint32_t &UcnVal, unsigned short &UcnLen,
264  FullSourceLoc Loc, DiagnosticsEngine *Diags,
265  const LangOptions &Features,
266  bool in_char_string_literal = false) {
267  const char *UcnBegin = ThisTokBuf;
268 
269  // Skip the '\u' char's.
270  ThisTokBuf += 2;
271 
272  if (ThisTokBuf == ThisTokEnd || !isHexDigit(*ThisTokBuf)) {
273  if (Diags)
274  Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
275  diag::err_hex_escape_no_digits) << StringRef(&ThisTokBuf[-1], 1);
276  return false;
277  }
278  UcnLen = (ThisTokBuf[-1] == 'u' ? 4 : 8);
279  unsigned short UcnLenSave = UcnLen;
280  for (; ThisTokBuf != ThisTokEnd && UcnLenSave; ++ThisTokBuf, UcnLenSave--) {
281  int CharVal = llvm::hexDigitValue(ThisTokBuf[0]);
282  if (CharVal == -1) break;
283  UcnVal <<= 4;
284  UcnVal |= CharVal;
285  }
286  // If we didn't consume the proper number of digits, there is a problem.
287  if (UcnLenSave) {
288  if (Diags)
289  Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
290  diag::err_ucn_escape_incomplete);
291  return false;
292  }
293 
294  // Check UCN constraints (C99 6.4.3p2) [C++11 lex.charset p2]
295  if ((0xD800 <= UcnVal && UcnVal <= 0xDFFF) || // surrogate codepoints
296  UcnVal > 0x10FFFF) { // maximum legal UTF32 value
297  if (Diags)
298  Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
299  diag::err_ucn_escape_invalid);
300  return false;
301  }
302 
303  // C++11 allows UCNs that refer to control characters and basic source
304  // characters inside character and string literals
305  if (UcnVal < 0xa0 &&
306  (UcnVal != 0x24 && UcnVal != 0x40 && UcnVal != 0x60)) { // $, @, `
307  bool IsError = (!Features.CPlusPlus11 || !in_char_string_literal);
308  if (Diags) {
309  char BasicSCSChar = UcnVal;
310  if (UcnVal >= 0x20 && UcnVal < 0x7f)
311  Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
312  IsError ? diag::err_ucn_escape_basic_scs :
313  diag::warn_cxx98_compat_literal_ucn_escape_basic_scs)
314  << StringRef(&BasicSCSChar, 1);
315  else
316  Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
317  IsError ? diag::err_ucn_control_character :
318  diag::warn_cxx98_compat_literal_ucn_control_character);
319  }
320  if (IsError)
321  return false;
322  }
323 
324  if (!Features.CPlusPlus && !Features.C99 && Diags)
325  Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
326  diag::warn_ucn_not_valid_in_c89_literal);
327 
328  return true;
329 }
330 
331 /// MeasureUCNEscape - Determine the number of bytes within the resulting string
332 /// which this UCN will occupy.
333 static int MeasureUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf,
334  const char *ThisTokEnd, unsigned CharByteWidth,
335  const LangOptions &Features, bool &HadError) {
336  // UTF-32: 4 bytes per escape.
337  if (CharByteWidth == 4)
338  return 4;
339 
340  uint32_t UcnVal = 0;
341  unsigned short UcnLen = 0;
342  FullSourceLoc Loc;
343 
344  if (!ProcessUCNEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd, UcnVal,
345  UcnLen, Loc, nullptr, Features, true)) {
346  HadError = true;
347  return 0;
348  }
349 
350  // UTF-16: 2 bytes for BMP, 4 bytes otherwise.
351  if (CharByteWidth == 2)
352  return UcnVal <= 0xFFFF ? 2 : 4;
353 
354  // UTF-8.
355  if (UcnVal < 0x80)
356  return 1;
357  if (UcnVal < 0x800)
358  return 2;
359  if (UcnVal < 0x10000)
360  return 3;
361  return 4;
362 }
363 
364 /// EncodeUCNEscape - Read the Universal Character Name, check constraints and
365 /// convert the UTF32 to UTF8 or UTF16. This is a subroutine of
366 /// StringLiteralParser. When we decide to implement UCN's for identifiers,
367 /// we will likely rework our support for UCN's.
368 static void EncodeUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf,
369  const char *ThisTokEnd,
370  char *&ResultBuf, bool &HadError,
371  FullSourceLoc Loc, unsigned CharByteWidth,
372  DiagnosticsEngine *Diags,
373  const LangOptions &Features) {
374  typedef uint32_t UTF32;
375  UTF32 UcnVal = 0;
376  unsigned short UcnLen = 0;
377  if (!ProcessUCNEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd, UcnVal, UcnLen,
378  Loc, Diags, Features, true)) {
379  HadError = true;
380  return;
381  }
382 
383  assert((CharByteWidth == 1 || CharByteWidth == 2 || CharByteWidth == 4) &&
384  "only character widths of 1, 2, or 4 bytes supported");
385 
386  (void)UcnLen;
387  assert((UcnLen== 4 || UcnLen== 8) && "only ucn length of 4 or 8 supported");
388 
389  if (CharByteWidth == 4) {
390  // FIXME: Make the type of the result buffer correct instead of
391  // using reinterpret_cast.
392  UTF32 *ResultPtr = reinterpret_cast<UTF32*>(ResultBuf);
393  *ResultPtr = UcnVal;
394  ResultBuf += 4;
395  return;
396  }
397 
398  if (CharByteWidth == 2) {
399  // FIXME: Make the type of the result buffer correct instead of
400  // using reinterpret_cast.
401  UTF16 *ResultPtr = reinterpret_cast<UTF16*>(ResultBuf);
402 
403  if (UcnVal <= (UTF32)0xFFFF) {
404  *ResultPtr = UcnVal;
405  ResultBuf += 2;
406  return;
407  }
408 
409  // Convert to UTF16.
410  UcnVal -= 0x10000;
411  *ResultPtr = 0xD800 + (UcnVal >> 10);
412  *(ResultPtr+1) = 0xDC00 + (UcnVal & 0x3FF);
413  ResultBuf += 4;
414  return;
415  }
416 
417  assert(CharByteWidth == 1 && "UTF-8 encoding is only for 1 byte characters");
418 
419  // Now that we've parsed/checked the UCN, we convert from UTF32->UTF8.
420  // The conversion below was inspired by:
421  // http://www.unicode.org/Public/PROGRAMS/CVTUTF/ConvertUTF.c
422  // First, we determine how many bytes the result will require.
423  typedef uint8_t UTF8;
424 
425  unsigned short bytesToWrite = 0;
426  if (UcnVal < (UTF32)0x80)
427  bytesToWrite = 1;
428  else if (UcnVal < (UTF32)0x800)
429  bytesToWrite = 2;
430  else if (UcnVal < (UTF32)0x10000)
431  bytesToWrite = 3;
432  else
433  bytesToWrite = 4;
434 
435  const unsigned byteMask = 0xBF;
436  const unsigned byteMark = 0x80;
437 
438  // Once the bits are split out into bytes of UTF8, this is a mask OR-ed
439  // into the first byte, depending on how many bytes follow.
440  static const UTF8 firstByteMark[5] = {
441  0x00, 0x00, 0xC0, 0xE0, 0xF0
442  };
443  // Finally, we write the bytes into ResultBuf.
444  ResultBuf += bytesToWrite;
445  switch (bytesToWrite) { // note: everything falls through.
446  case 4: *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6;
447  case 3: *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6;
448  case 2: *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6;
449  case 1: *--ResultBuf = (UTF8) (UcnVal | firstByteMark[bytesToWrite]);
450  }
451  // Update the buffer.
452  ResultBuf += bytesToWrite;
453 }
454 
455 
456 /// integer-constant: [C99 6.4.4.1]
457 /// decimal-constant integer-suffix
458 /// octal-constant integer-suffix
459 /// hexadecimal-constant integer-suffix
460 /// binary-literal integer-suffix [GNU, C++1y]
461 /// user-defined-integer-literal: [C++11 lex.ext]
462 /// decimal-literal ud-suffix
463 /// octal-literal ud-suffix
464 /// hexadecimal-literal ud-suffix
465 /// binary-literal ud-suffix [GNU, C++1y]
466 /// decimal-constant:
467 /// nonzero-digit
468 /// decimal-constant digit
469 /// octal-constant:
470 /// 0
471 /// octal-constant octal-digit
472 /// hexadecimal-constant:
473 /// hexadecimal-prefix hexadecimal-digit
474 /// hexadecimal-constant hexadecimal-digit
475 /// hexadecimal-prefix: one of
476 /// 0x 0X
477 /// binary-literal:
478 /// 0b binary-digit
479 /// 0B binary-digit
480 /// binary-literal binary-digit
481 /// integer-suffix:
482 /// unsigned-suffix [long-suffix]
483 /// unsigned-suffix [long-long-suffix]
484 /// long-suffix [unsigned-suffix]
485 /// long-long-suffix [unsigned-sufix]
486 /// nonzero-digit:
487 /// 1 2 3 4 5 6 7 8 9
488 /// octal-digit:
489 /// 0 1 2 3 4 5 6 7
490 /// hexadecimal-digit:
491 /// 0 1 2 3 4 5 6 7 8 9
492 /// a b c d e f
493 /// A B C D E F
494 /// binary-digit:
495 /// 0
496 /// 1
497 /// unsigned-suffix: one of
498 /// u U
499 /// long-suffix: one of
500 /// l L
501 /// long-long-suffix: one of
502 /// ll LL
503 ///
504 /// floating-constant: [C99 6.4.4.2]
505 /// TODO: add rules...
506 ///
508  SourceLocation TokLoc,
509  Preprocessor &PP)
510  : PP(PP), ThisTokBegin(TokSpelling.begin()), ThisTokEnd(TokSpelling.end()) {
511 
512  // This routine assumes that the range begin/end matches the regex for integer
513  // and FP constants (specifically, the 'pp-number' regex), and assumes that
514  // the byte at "*end" is both valid and not part of the regex. Because of
515  // this, it doesn't have to check for 'overscan' in various places.
516  assert(!isPreprocessingNumberBody(*ThisTokEnd) && "didn't maximally munch?");
517 
518  s = DigitsBegin = ThisTokBegin;
519  saw_exponent = false;
520  saw_period = false;
521  saw_ud_suffix = false;
522  isLong = false;
523  isUnsigned = false;
524  isLongLong = false;
525  isFloat = false;
526  isImaginary = false;
527  MicrosoftInteger = 0;
528  hadError = false;
529 
530  if (*s == '0') { // parse radix
531  ParseNumberStartingWithZero(TokLoc);
532  if (hadError)
533  return;
534  } else { // the first digit is non-zero
535  radix = 10;
536  s = SkipDigits(s);
537  if (s == ThisTokEnd) {
538  // Done.
539  } else if (isHexDigit(*s) && !(*s == 'e' || *s == 'E')) {
540  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin),
541  diag::err_invalid_decimal_digit) << StringRef(s, 1);
542  hadError = true;
543  return;
544  } else if (*s == '.') {
545  checkSeparator(TokLoc, s, CSK_AfterDigits);
546  s++;
547  saw_period = true;
548  checkSeparator(TokLoc, s, CSK_BeforeDigits);
549  s = SkipDigits(s);
550  }
551  if ((*s == 'e' || *s == 'E')) { // exponent
552  checkSeparator(TokLoc, s, CSK_AfterDigits);
553  const char *Exponent = s;
554  s++;
555  saw_exponent = true;
556  if (*s == '+' || *s == '-') s++; // sign
557  checkSeparator(TokLoc, s, CSK_BeforeDigits);
558  const char *first_non_digit = SkipDigits(s);
559  if (first_non_digit != s) {
560  s = first_non_digit;
561  } else {
562  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent - ThisTokBegin),
563  diag::err_exponent_has_no_digits);
564  hadError = true;
565  return;
566  }
567  }
568  }
569 
570  SuffixBegin = s;
571  checkSeparator(TokLoc, s, CSK_AfterDigits);
572 
573  // Parse the suffix. At this point we can classify whether we have an FP or
574  // integer constant.
575  bool isFPConstant = isFloatingLiteral();
576  const char *ImaginarySuffixLoc = nullptr;
577 
578  // Loop over all of the characters of the suffix. If we see something bad,
579  // we break out of the loop.
580  for (; s != ThisTokEnd; ++s) {
581  switch (*s) {
582  case 'f': // FP Suffix for "float"
583  case 'F':
584  if (!isFPConstant) break; // Error for integer constant.
585  if (isFloat || isLong) break; // FF, LF invalid.
586  isFloat = true;
587  continue; // Success.
588  case 'u':
589  case 'U':
590  if (isFPConstant) break; // Error for floating constant.
591  if (isUnsigned) break; // Cannot be repeated.
592  isUnsigned = true;
593  continue; // Success.
594  case 'l':
595  case 'L':
596  if (isLong || isLongLong) break; // Cannot be repeated.
597  if (isFloat) break; // LF invalid.
598 
599  // Check for long long. The L's need to be adjacent and the same case.
600  if (s[1] == s[0]) {
601  assert(s + 1 < ThisTokEnd && "didn't maximally munch?");
602  if (isFPConstant) break; // long long invalid for floats.
603  isLongLong = true;
604  ++s; // Eat both of them.
605  } else {
606  isLong = true;
607  }
608  continue; // Success.
609  case 'i':
610  case 'I':
611  if (PP.getLangOpts().MicrosoftExt) {
613  break;
614 
615  if (!isFPConstant) {
616  // Allow i8, i16, i32, i64, and i128.
617  switch (s[1]) {
618  case '8':
619  s += 2; // i8 suffix
620  MicrosoftInteger = 8;
621  break;
622  case '1':
623  if (s[2] == '6') {
624  s += 3; // i16 suffix
625  MicrosoftInteger = 16;
626  } else if (s[2] == '2' && s[3] == '8') {
627  s += 4; // i128 suffix
628  MicrosoftInteger = 128;
629  }
630  break;
631  case '3':
632  if (s[2] == '2') {
633  s += 3; // i32 suffix
634  MicrosoftInteger = 32;
635  }
636  break;
637  case '6':
638  if (s[2] == '4') {
639  s += 3; // i64 suffix
640  MicrosoftInteger = 64;
641  }
642  break;
643  default:
644  break;
645  }
646  }
647  if (MicrosoftInteger) {
648  assert(s <= ThisTokEnd && "didn't maximally munch?");
649  break;
650  }
651  }
652  // "i", "if", and "il" are user-defined suffixes in C++1y.
653  if (*s == 'i' && PP.getLangOpts().CPlusPlus14)
654  break;
655  // fall through.
656  case 'j':
657  case 'J':
658  if (isImaginary) break; // Cannot be repeated.
659  isImaginary = true;
660  ImaginarySuffixLoc = s;
661  continue; // Success.
662  }
663  // If we reached here, there was an error or a ud-suffix.
664  break;
665  }
666 
667  if (s != ThisTokEnd) {
668  // FIXME: Don't bother expanding UCNs if !tok.hasUCN().
669  expandUCNs(UDSuffixBuf, StringRef(SuffixBegin, ThisTokEnd - SuffixBegin));
670  if (isValidUDSuffix(PP.getLangOpts(), UDSuffixBuf)) {
671  // Any suffix pieces we might have parsed are actually part of the
672  // ud-suffix.
673  isLong = false;
674  isUnsigned = false;
675  isLongLong = false;
676  isFloat = false;
677  isImaginary = false;
678  MicrosoftInteger = 0;
679 
680  saw_ud_suffix = true;
681  return;
682  }
683 
684  // Report an error if there are any.
685  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, SuffixBegin - ThisTokBegin),
686  isFPConstant ? diag::err_invalid_suffix_float_constant :
687  diag::err_invalid_suffix_integer_constant)
688  << StringRef(SuffixBegin, ThisTokEnd-SuffixBegin);
689  hadError = true;
690  return;
691  }
692 
693  if (isImaginary) {
694  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc,
695  ImaginarySuffixLoc - ThisTokBegin),
696  diag::ext_imaginary_constant);
697  }
698 }
699 
700 /// Determine whether a suffix is a valid ud-suffix. We avoid treating reserved
701 /// suffixes as ud-suffixes, because the diagnostic experience is better if we
702 /// treat it as an invalid suffix.
704  StringRef Suffix) {
705  if (!LangOpts.CPlusPlus11 || Suffix.empty())
706  return false;
707 
708  // By C++11 [lex.ext]p10, ud-suffixes starting with an '_' are always valid.
709  if (Suffix[0] == '_')
710  return true;
711 
712  // In C++11, there are no library suffixes.
713  if (!LangOpts.CPlusPlus14)
714  return false;
715 
716  // In C++1y, "s", "h", "min", "ms", "us", and "ns" are used in the library.
717  // Per tweaked N3660, "il", "i", and "if" are also used in the library.
718  return llvm::StringSwitch<bool>(Suffix)
719  .Cases("h", "min", "s", true)
720  .Cases("ms", "us", "ns", true)
721  .Cases("il", "i", "if", true)
722  .Default(false);
723 }
724 
725 void NumericLiteralParser::checkSeparator(SourceLocation TokLoc,
726  const char *Pos,
727  CheckSeparatorKind IsAfterDigits) {
728  if (IsAfterDigits == CSK_AfterDigits) {
729  if (Pos == ThisTokBegin)
730  return;
731  --Pos;
732  } else if (Pos == ThisTokEnd)
733  return;
734 
735  if (isDigitSeparator(*Pos))
736  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Pos - ThisTokBegin),
737  diag::err_digit_separator_not_between_digits)
738  << IsAfterDigits;
739 }
740 
741 /// ParseNumberStartingWithZero - This method is called when the first character
742 /// of the number is found to be a zero. This means it is either an octal
743 /// number (like '04') or a hex number ('0x123a') a binary number ('0b1010') or
744 /// a floating point number (01239.123e4). Eat the prefix, determining the
745 /// radix etc.
746 void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) {
747  assert(s[0] == '0' && "Invalid method call");
748  s++;
749 
750  int c1 = s[0];
751 
752  // Handle a hex number like 0x1234.
753  if ((c1 == 'x' || c1 == 'X') && (isHexDigit(s[1]) || s[1] == '.')) {
754  s++;
755  assert(s < ThisTokEnd && "didn't maximally munch?");
756  radix = 16;
757  DigitsBegin = s;
758  s = SkipHexDigits(s);
759  bool noSignificand = (s == DigitsBegin);
760  if (s == ThisTokEnd) {
761  // Done.
762  } else if (*s == '.') {
763  s++;
764  saw_period = true;
765  const char *floatDigitsBegin = s;
766  checkSeparator(TokLoc, s, CSK_BeforeDigits);
767  s = SkipHexDigits(s);
768  noSignificand &= (floatDigitsBegin == s);
769  }
770 
771  if (noSignificand) {
772  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin),
773  diag::err_hexconstant_requires_digits);
774  hadError = true;
775  return;
776  }
777 
778  // A binary exponent can appear with or with a '.'. If dotted, the
779  // binary exponent is required.
780  if (*s == 'p' || *s == 'P') {
781  checkSeparator(TokLoc, s, CSK_AfterDigits);
782  const char *Exponent = s;
783  s++;
784  saw_exponent = true;
785  if (*s == '+' || *s == '-') s++; // sign
786  const char *first_non_digit = SkipDigits(s);
787  if (first_non_digit == s) {
788  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-ThisTokBegin),
789  diag::err_exponent_has_no_digits);
790  hadError = true;
791  return;
792  }
793  checkSeparator(TokLoc, s, CSK_BeforeDigits);
794  s = first_non_digit;
795 
796  if (!PP.getLangOpts().HexFloats)
797  PP.Diag(TokLoc, diag::ext_hexconstant_invalid);
798  } else if (saw_period) {
799  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
800  diag::err_hexconstant_requires_exponent);
801  hadError = true;
802  }
803  return;
804  }
805 
806  // Handle simple binary numbers 0b01010
807  if ((c1 == 'b' || c1 == 'B') && (s[1] == '0' || s[1] == '1')) {
808  // 0b101010 is a C++1y / GCC extension.
809  PP.Diag(TokLoc,
810  PP.getLangOpts().CPlusPlus14
811  ? diag::warn_cxx11_compat_binary_literal
812  : PP.getLangOpts().CPlusPlus
813  ? diag::ext_binary_literal_cxx14
814  : diag::ext_binary_literal);
815  ++s;
816  assert(s < ThisTokEnd && "didn't maximally munch?");
817  radix = 2;
818  DigitsBegin = s;
819  s = SkipBinaryDigits(s);
820  if (s == ThisTokEnd) {
821  // Done.
822  } else if (isHexDigit(*s)) {
823  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
824  diag::err_invalid_binary_digit) << StringRef(s, 1);
825  hadError = true;
826  }
827  // Other suffixes will be diagnosed by the caller.
828  return;
829  }
830 
831  // For now, the radix is set to 8. If we discover that we have a
832  // floating point constant, the radix will change to 10. Octal floating
833  // point constants are not permitted (only decimal and hexadecimal).
834  radix = 8;
835  DigitsBegin = s;
836  s = SkipOctalDigits(s);
837  if (s == ThisTokEnd)
838  return; // Done, simple octal number like 01234
839 
840  // If we have some other non-octal digit that *is* a decimal digit, see if
841  // this is part of a floating point number like 094.123 or 09e1.
842  if (isDigit(*s)) {
843  const char *EndDecimal = SkipDigits(s);
844  if (EndDecimal[0] == '.' || EndDecimal[0] == 'e' || EndDecimal[0] == 'E') {
845  s = EndDecimal;
846  radix = 10;
847  }
848  }
849 
850  // If we have a hex digit other than 'e' (which denotes a FP exponent) then
851  // the code is using an incorrect base.
852  if (isHexDigit(*s) && *s != 'e' && *s != 'E') {
853  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
854  diag::err_invalid_octal_digit) << StringRef(s, 1);
855  hadError = true;
856  return;
857  }
858 
859  if (*s == '.') {
860  s++;
861  radix = 10;
862  saw_period = true;
863  checkSeparator(TokLoc, s, CSK_BeforeDigits);
864  s = SkipDigits(s); // Skip suffix.
865  }
866  if (*s == 'e' || *s == 'E') { // exponent
867  checkSeparator(TokLoc, s, CSK_AfterDigits);
868  const char *Exponent = s;
869  s++;
870  radix = 10;
871  saw_exponent = true;
872  if (*s == '+' || *s == '-') s++; // sign
873  const char *first_non_digit = SkipDigits(s);
874  if (first_non_digit != s) {
875  checkSeparator(TokLoc, s, CSK_BeforeDigits);
876  s = first_non_digit;
877  } else {
878  PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-ThisTokBegin),
879  diag::err_exponent_has_no_digits);
880  hadError = true;
881  return;
882  }
883  }
884 }
885 
886 static bool alwaysFitsInto64Bits(unsigned Radix, unsigned NumDigits) {
887  switch (Radix) {
888  case 2:
889  return NumDigits <= 64;
890  case 8:
891  return NumDigits <= 64 / 3; // Digits are groups of 3 bits.
892  case 10:
893  return NumDigits <= 19; // floor(log10(2^64))
894  case 16:
895  return NumDigits <= 64 / 4; // Digits are groups of 4 bits.
896  default:
897  llvm_unreachable("impossible Radix");
898  }
899 }
900 
901 /// GetIntegerValue - Convert this numeric literal value to an APInt that
902 /// matches Val's input width. If there is an overflow, set Val to the low bits
903 /// of the result and return true. Otherwise, return false.
905  // Fast path: Compute a conservative bound on the maximum number of
906  // bits per digit in this radix. If we can't possibly overflow a
907  // uint64 based on that bound then do the simple conversion to
908  // integer. This avoids the expensive overflow checking below, and
909  // handles the common cases that matter (small decimal integers and
910  // hex/octal values which don't overflow).
911  const unsigned NumDigits = SuffixBegin - DigitsBegin;
912  if (alwaysFitsInto64Bits(radix, NumDigits)) {
913  uint64_t N = 0;
914  for (const char *Ptr = DigitsBegin; Ptr != SuffixBegin; ++Ptr)
915  if (!isDigitSeparator(*Ptr))
916  N = N * radix + llvm::hexDigitValue(*Ptr);
917 
918  // This will truncate the value to Val's input width. Simply check
919  // for overflow by comparing.
920  Val = N;
921  return Val.getZExtValue() != N;
922  }
923 
924  Val = 0;
925  const char *Ptr = DigitsBegin;
926 
927  llvm::APInt RadixVal(Val.getBitWidth(), radix);
928  llvm::APInt CharVal(Val.getBitWidth(), 0);
929  llvm::APInt OldVal = Val;
930 
931  bool OverflowOccurred = false;
932  while (Ptr < SuffixBegin) {
933  if (isDigitSeparator(*Ptr)) {
934  ++Ptr;
935  continue;
936  }
937 
938  unsigned C = llvm::hexDigitValue(*Ptr++);
939 
940  // If this letter is out of bound for this radix, reject it.
941  assert(C < radix && "NumericLiteralParser ctor should have rejected this");
942 
943  CharVal = C;
944 
945  // Add the digit to the value in the appropriate radix. If adding in digits
946  // made the value smaller, then this overflowed.
947  OldVal = Val;
948 
949  // Multiply by radix, did overflow occur on the multiply?
950  Val *= RadixVal;
951  OverflowOccurred |= Val.udiv(RadixVal) != OldVal;
952 
953  // Add value, did overflow occur on the value?
954  // (a + b) ult b <=> overflow
955  Val += CharVal;
956  OverflowOccurred |= Val.ult(CharVal);
957  }
958  return OverflowOccurred;
959 }
960 
961 llvm::APFloat::opStatus
962 NumericLiteralParser::GetFloatValue(llvm::APFloat &Result) {
963  using llvm::APFloat;
964 
965  unsigned n = std::min(SuffixBegin - ThisTokBegin, ThisTokEnd - ThisTokBegin);
966 
967  llvm::SmallString<16> Buffer;
968  StringRef Str(ThisTokBegin, n);
969  if (Str.find('\'') != StringRef::npos) {
970  Buffer.reserve(n);
971  std::remove_copy_if(Str.begin(), Str.end(), std::back_inserter(Buffer),
972  &isDigitSeparator);
973  Str = Buffer;
974  }
975 
976  return Result.convertFromString(Str, APFloat::rmNearestTiesToEven);
977 }
978 
979 
980 /// \verbatim
981 /// user-defined-character-literal: [C++11 lex.ext]
982 /// character-literal ud-suffix
983 /// ud-suffix:
984 /// identifier
985 /// character-literal: [C++11 lex.ccon]
986 /// ' c-char-sequence '
987 /// u' c-char-sequence '
988 /// U' c-char-sequence '
989 /// L' c-char-sequence '
990 /// c-char-sequence:
991 /// c-char
992 /// c-char-sequence c-char
993 /// c-char:
994 /// any member of the source character set except the single-quote ',
995 /// backslash \, or new-line character
996 /// escape-sequence
997 /// universal-character-name
998 /// escape-sequence:
999 /// simple-escape-sequence
1000 /// octal-escape-sequence
1001 /// hexadecimal-escape-sequence
1002 /// simple-escape-sequence:
1003 /// one of \' \" \? \\ \a \b \f \n \r \t \v
1004 /// octal-escape-sequence:
1005 /// \ octal-digit
1006 /// \ octal-digit octal-digit
1007 /// \ octal-digit octal-digit octal-digit
1008 /// hexadecimal-escape-sequence:
1009 /// \x hexadecimal-digit
1010 /// hexadecimal-escape-sequence hexadecimal-digit
1011 /// universal-character-name: [C++11 lex.charset]
1012 /// \u hex-quad
1013 /// \U hex-quad hex-quad
1014 /// hex-quad:
1015 /// hex-digit hex-digit hex-digit hex-digit
1016 /// \endverbatim
1017 ///
1018 CharLiteralParser::CharLiteralParser(const char *begin, const char *end,
1019  SourceLocation Loc, Preprocessor &PP,
1020  tok::TokenKind kind) {
1021  // At this point we know that the character matches the regex "(L|u|U)?'.*'".
1022  HadError = false;
1023 
1024  Kind = kind;
1025 
1026  const char *TokBegin = begin;
1027 
1028  // Skip over wide character determinant.
1029  if (Kind != tok::char_constant)
1030  ++begin;
1031  if (Kind == tok::utf8_char_constant)
1032  ++begin;
1033 
1034  // Skip over the entry quote.
1035  assert(begin[0] == '\'' && "Invalid token lexed");
1036  ++begin;
1037 
1038  // Remove an optional ud-suffix.
1039  if (end[-1] != '\'') {
1040  const char *UDSuffixEnd = end;
1041  do {
1042  --end;
1043  } while (end[-1] != '\'');
1044  // FIXME: Don't bother with this if !tok.hasUCN().
1045  expandUCNs(UDSuffixBuf, StringRef(end, UDSuffixEnd - end));
1046  UDSuffixOffset = end - TokBegin;
1047  }
1048 
1049  // Trim the ending quote.
1050  assert(end != begin && "Invalid token lexed");
1051  --end;
1052 
1053  // FIXME: The "Value" is an uint64_t so we can handle char literals of
1054  // up to 64-bits.
1055  // FIXME: This extensively assumes that 'char' is 8-bits.
1056  assert(PP.getTargetInfo().getCharWidth() == 8 &&
1057  "Assumes char is 8 bits");
1058  assert(PP.getTargetInfo().getIntWidth() <= 64 &&
1059  (PP.getTargetInfo().getIntWidth() & 7) == 0 &&
1060  "Assumes sizeof(int) on target is <= 64 and a multiple of char");
1061  assert(PP.getTargetInfo().getWCharWidth() <= 64 &&
1062  "Assumes sizeof(wchar) on target is <= 64");
1063 
1064  SmallVector<uint32_t, 4> codepoint_buffer;
1065  codepoint_buffer.resize(end - begin);
1066  uint32_t *buffer_begin = &codepoint_buffer.front();
1067  uint32_t *buffer_end = buffer_begin + codepoint_buffer.size();
1068 
1069  // Unicode escapes representing characters that cannot be correctly
1070  // represented in a single code unit are disallowed in character literals
1071  // by this implementation.
1072  uint32_t largest_character_for_kind;
1073  if (tok::wide_char_constant == Kind) {
1074  largest_character_for_kind =
1075  0xFFFFFFFFu >> (32-PP.getTargetInfo().getWCharWidth());
1076  } else if (tok::utf8_char_constant == Kind) {
1077  largest_character_for_kind = 0x7F;
1078  } else if (tok::utf16_char_constant == Kind) {
1079  largest_character_for_kind = 0xFFFF;
1080  } else if (tok::utf32_char_constant == Kind) {
1081  largest_character_for_kind = 0x10FFFF;
1082  } else {
1083  largest_character_for_kind = 0x7Fu;
1084  }
1085 
1086  while (begin != end) {
1087  // Is this a span of non-escape characters?
1088  if (begin[0] != '\\') {
1089  char const *start = begin;
1090  do {
1091  ++begin;
1092  } while (begin != end && *begin != '\\');
1093 
1094  char const *tmp_in_start = start;
1095  uint32_t *tmp_out_start = buffer_begin;
1096  ConversionResult res =
1097  ConvertUTF8toUTF32(reinterpret_cast<UTF8 const **>(&start),
1098  reinterpret_cast<UTF8 const *>(begin),
1099  &buffer_begin, buffer_end, strictConversion);
1100  if (res != conversionOK) {
1101  // If we see bad encoding for unprefixed character literals, warn and
1102  // simply copy the byte values, for compatibility with gcc and
1103  // older versions of clang.
1104  bool NoErrorOnBadEncoding = isAscii();
1105  unsigned Msg = diag::err_bad_character_encoding;
1106  if (NoErrorOnBadEncoding)
1107  Msg = diag::warn_bad_character_encoding;
1108  PP.Diag(Loc, Msg);
1109  if (NoErrorOnBadEncoding) {
1110  start = tmp_in_start;
1111  buffer_begin = tmp_out_start;
1112  for (; start != begin; ++start, ++buffer_begin)
1113  *buffer_begin = static_cast<uint8_t>(*start);
1114  } else {
1115  HadError = true;
1116  }
1117  } else {
1118  for (; tmp_out_start < buffer_begin; ++tmp_out_start) {
1119  if (*tmp_out_start > largest_character_for_kind) {
1120  HadError = true;
1121  PP.Diag(Loc, diag::err_character_too_large);
1122  }
1123  }
1124  }
1125 
1126  continue;
1127  }
1128  // Is this a Universal Character Name escape?
1129  if (begin[1] == 'u' || begin[1] == 'U') {
1130  unsigned short UcnLen = 0;
1131  if (!ProcessUCNEscape(TokBegin, begin, end, *buffer_begin, UcnLen,
1132  FullSourceLoc(Loc, PP.getSourceManager()),
1133  &PP.getDiagnostics(), PP.getLangOpts(), true)) {
1134  HadError = true;
1135  } else if (*buffer_begin > largest_character_for_kind) {
1136  HadError = true;
1137  PP.Diag(Loc, diag::err_character_too_large);
1138  }
1139 
1140  ++buffer_begin;
1141  continue;
1142  }
1143  unsigned CharWidth = getCharWidth(Kind, PP.getTargetInfo());
1144  uint64_t result =
1145  ProcessCharEscape(TokBegin, begin, end, HadError,
1146  FullSourceLoc(Loc,PP.getSourceManager()),
1147  CharWidth, &PP.getDiagnostics(), PP.getLangOpts());
1148  *buffer_begin++ = result;
1149  }
1150 
1151  unsigned NumCharsSoFar = buffer_begin - &codepoint_buffer.front();
1152 
1153  if (NumCharsSoFar > 1) {
1154  if (isWide())
1155  PP.Diag(Loc, diag::warn_extraneous_char_constant);
1156  else if (isAscii() && NumCharsSoFar == 4)
1157  PP.Diag(Loc, diag::ext_four_char_character_literal);
1158  else if (isAscii())
1159  PP.Diag(Loc, diag::ext_multichar_character_literal);
1160  else
1161  PP.Diag(Loc, diag::err_multichar_utf_character_literal);
1162  IsMultiChar = true;
1163  } else {
1164  IsMultiChar = false;
1165  }
1166 
1167  llvm::APInt LitVal(PP.getTargetInfo().getIntWidth(), 0);
1168 
1169  // Narrow character literals act as though their value is concatenated
1170  // in this implementation, but warn on overflow.
1171  bool multi_char_too_long = false;
1172  if (isAscii() && isMultiChar()) {
1173  LitVal = 0;
1174  for (size_t i = 0; i < NumCharsSoFar; ++i) {
1175  // check for enough leading zeros to shift into
1176  multi_char_too_long |= (LitVal.countLeadingZeros() < 8);
1177  LitVal <<= 8;
1178  LitVal = LitVal + (codepoint_buffer[i] & 0xFF);
1179  }
1180  } else if (NumCharsSoFar > 0) {
1181  // otherwise just take the last character
1182  LitVal = buffer_begin[-1];
1183  }
1184 
1185  if (!HadError && multi_char_too_long) {
1186  PP.Diag(Loc, diag::warn_char_constant_too_large);
1187  }
1188 
1189  // Transfer the value from APInt to uint64_t
1190  Value = LitVal.getZExtValue();
1191 
1192  // If this is a single narrow character, sign extend it (e.g. '\xFF' is "-1")
1193  // if 'char' is signed for this target (C99 6.4.4.4p10). Note that multiple
1194  // character constants are not sign extended in the this implementation:
1195  // '\xFF\xFF' = 65536 and '\x0\xFF' = 255, which matches GCC.
1196  if (isAscii() && NumCharsSoFar == 1 && (Value & 128) &&
1197  PP.getLangOpts().CharIsSigned)
1198  Value = (signed char)Value;
1199 }
1200 
1201 /// \verbatim
1202 /// string-literal: [C++0x lex.string]
1203 /// encoding-prefix " [s-char-sequence] "
1204 /// encoding-prefix R raw-string
1205 /// encoding-prefix:
1206 /// u8
1207 /// u
1208 /// U
1209 /// L
1210 /// s-char-sequence:
1211 /// s-char
1212 /// s-char-sequence s-char
1213 /// s-char:
1214 /// any member of the source character set except the double-quote ",
1215 /// backslash \, or new-line character
1216 /// escape-sequence
1217 /// universal-character-name
1218 /// raw-string:
1219 /// " d-char-sequence ( r-char-sequence ) d-char-sequence "
1220 /// r-char-sequence:
1221 /// r-char
1222 /// r-char-sequence r-char
1223 /// r-char:
1224 /// any member of the source character set, except a right parenthesis )
1225 /// followed by the initial d-char-sequence (which may be empty)
1226 /// followed by a double quote ".
1227 /// d-char-sequence:
1228 /// d-char
1229 /// d-char-sequence d-char
1230 /// d-char:
1231 /// any member of the basic source character set except:
1232 /// space, the left parenthesis (, the right parenthesis ),
1233 /// the backslash \, and the control characters representing horizontal
1234 /// tab, vertical tab, form feed, and newline.
1235 /// escape-sequence: [C++0x lex.ccon]
1236 /// simple-escape-sequence
1237 /// octal-escape-sequence
1238 /// hexadecimal-escape-sequence
1239 /// simple-escape-sequence:
1240 /// one of \' \" \? \\ \a \b \f \n \r \t \v
1241 /// octal-escape-sequence:
1242 /// \ octal-digit
1243 /// \ octal-digit octal-digit
1244 /// \ octal-digit octal-digit octal-digit
1245 /// hexadecimal-escape-sequence:
1246 /// \x hexadecimal-digit
1247 /// hexadecimal-escape-sequence hexadecimal-digit
1248 /// universal-character-name:
1249 /// \u hex-quad
1250 /// \U hex-quad hex-quad
1251 /// hex-quad:
1252 /// hex-digit hex-digit hex-digit hex-digit
1253 /// \endverbatim
1254 ///
1257  Preprocessor &PP, bool Complain)
1258  : SM(PP.getSourceManager()), Features(PP.getLangOpts()),
1259  Target(PP.getTargetInfo()), Diags(Complain ? &PP.getDiagnostics() :nullptr),
1260  MaxTokenLength(0), SizeBound(0), CharByteWidth(0), Kind(tok::unknown),
1261  ResultPtr(ResultBuf.data()), hadError(false), Pascal(false) {
1262  init(StringToks);
1263 }
1264 
1265 void StringLiteralParser::init(ArrayRef<Token> StringToks){
1266  // The literal token may have come from an invalid source location (e.g. due
1267  // to a PCH error), in which case the token length will be 0.
1268  if (StringToks.empty() || StringToks[0].getLength() < 2)
1269  return DiagnoseLexingError(SourceLocation());
1270 
1271  // Scan all of the string portions, remember the max individual token length,
1272  // computing a bound on the concatenated string length, and see whether any
1273  // piece is a wide-string. If any of the string portions is a wide-string
1274  // literal, the result is a wide-string literal [C99 6.4.5p4].
1275  assert(!StringToks.empty() && "expected at least one token");
1276  MaxTokenLength = StringToks[0].getLength();
1277  assert(StringToks[0].getLength() >= 2 && "literal token is invalid!");
1278  SizeBound = StringToks[0].getLength()-2; // -2 for "".
1279  Kind = StringToks[0].getKind();
1280 
1281  hadError = false;
1282 
1283  // Implement Translation Phase #6: concatenation of string literals
1284  /// (C99 5.1.1.2p1). The common case is only one string fragment.
1285  for (unsigned i = 1; i != StringToks.size(); ++i) {
1286  if (StringToks[i].getLength() < 2)
1287  return DiagnoseLexingError(StringToks[i].getLocation());
1288 
1289  // The string could be shorter than this if it needs cleaning, but this is a
1290  // reasonable bound, which is all we need.
1291  assert(StringToks[i].getLength() >= 2 && "literal token is invalid!");
1292  SizeBound += StringToks[i].getLength()-2; // -2 for "".
1293 
1294  // Remember maximum string piece length.
1295  if (StringToks[i].getLength() > MaxTokenLength)
1296  MaxTokenLength = StringToks[i].getLength();
1297 
1298  // Remember if we see any wide or utf-8/16/32 strings.
1299  // Also check for illegal concatenations.
1300  if (StringToks[i].isNot(Kind) && StringToks[i].isNot(tok::string_literal)) {
1301  if (isAscii()) {
1302  Kind = StringToks[i].getKind();
1303  } else {
1304  if (Diags)
1305  Diags->Report(StringToks[i].getLocation(),
1306  diag::err_unsupported_string_concat);
1307  hadError = true;
1308  }
1309  }
1310  }
1311 
1312  // Include space for the null terminator.
1313  ++SizeBound;
1314 
1315  // TODO: K&R warning: "traditional C rejects string constant concatenation"
1316 
1317  // Get the width in bytes of char/wchar_t/char16_t/char32_t
1318  CharByteWidth = getCharWidth(Kind, Target);
1319  assert((CharByteWidth & 7) == 0 && "Assumes character size is byte multiple");
1320  CharByteWidth /= 8;
1321 
1322  // The output buffer size needs to be large enough to hold wide characters.
1323  // This is a worst-case assumption which basically corresponds to L"" "long".
1324  SizeBound *= CharByteWidth;
1325 
1326  // Size the temporary buffer to hold the result string data.
1327  ResultBuf.resize(SizeBound);
1328 
1329  // Likewise, but for each string piece.
1330  SmallString<512> TokenBuf;
1331  TokenBuf.resize(MaxTokenLength);
1332 
1333  // Loop over all the strings, getting their spelling, and expanding them to
1334  // wide strings as appropriate.
1335  ResultPtr = &ResultBuf[0]; // Next byte to fill in.
1336 
1337  Pascal = false;
1338 
1339  SourceLocation UDSuffixTokLoc;
1340 
1341  for (unsigned i = 0, e = StringToks.size(); i != e; ++i) {
1342  const char *ThisTokBuf = &TokenBuf[0];
1343  // Get the spelling of the token, which eliminates trigraphs, etc. We know
1344  // that ThisTokBuf points to a buffer that is big enough for the whole token
1345  // and 'spelled' tokens can only shrink.
1346  bool StringInvalid = false;
1347  unsigned ThisTokLen =
1348  Lexer::getSpelling(StringToks[i], ThisTokBuf, SM, Features,
1349  &StringInvalid);
1350  if (StringInvalid)
1351  return DiagnoseLexingError(StringToks[i].getLocation());
1352 
1353  const char *ThisTokBegin = ThisTokBuf;
1354  const char *ThisTokEnd = ThisTokBuf+ThisTokLen;
1355 
1356  // Remove an optional ud-suffix.
1357  if (ThisTokEnd[-1] != '"') {
1358  const char *UDSuffixEnd = ThisTokEnd;
1359  do {
1360  --ThisTokEnd;
1361  } while (ThisTokEnd[-1] != '"');
1362 
1363  StringRef UDSuffix(ThisTokEnd, UDSuffixEnd - ThisTokEnd);
1364 
1365  if (UDSuffixBuf.empty()) {
1366  if (StringToks[i].hasUCN())
1367  expandUCNs(UDSuffixBuf, UDSuffix);
1368  else
1369  UDSuffixBuf.assign(UDSuffix);
1370  UDSuffixToken = i;
1371  UDSuffixOffset = ThisTokEnd - ThisTokBuf;
1372  UDSuffixTokLoc = StringToks[i].getLocation();
1373  } else {
1374  SmallString<32> ExpandedUDSuffix;
1375  if (StringToks[i].hasUCN()) {
1376  expandUCNs(ExpandedUDSuffix, UDSuffix);
1377  UDSuffix = ExpandedUDSuffix;
1378  }
1379 
1380  // C++11 [lex.ext]p8: At the end of phase 6, if a string literal is the
1381  // result of a concatenation involving at least one user-defined-string-
1382  // literal, all the participating user-defined-string-literals shall
1383  // have the same ud-suffix.
1384  if (UDSuffixBuf != UDSuffix) {
1385  if (Diags) {
1386  SourceLocation TokLoc = StringToks[i].getLocation();
1387  Diags->Report(TokLoc, diag::err_string_concat_mixed_suffix)
1388  << UDSuffixBuf << UDSuffix
1389  << SourceRange(UDSuffixTokLoc, UDSuffixTokLoc)
1390  << SourceRange(TokLoc, TokLoc);
1391  }
1392  hadError = true;
1393  }
1394  }
1395  }
1396 
1397  // Strip the end quote.
1398  --ThisTokEnd;
1399 
1400  // TODO: Input character set mapping support.
1401 
1402  // Skip marker for wide or unicode strings.
1403  if (ThisTokBuf[0] == 'L' || ThisTokBuf[0] == 'u' || ThisTokBuf[0] == 'U') {
1404  ++ThisTokBuf;
1405  // Skip 8 of u8 marker for utf8 strings.
1406  if (ThisTokBuf[0] == '8')
1407  ++ThisTokBuf;
1408  }
1409 
1410  // Check for raw string
1411  if (ThisTokBuf[0] == 'R') {
1412  ThisTokBuf += 2; // skip R"
1413 
1414  const char *Prefix = ThisTokBuf;
1415  while (ThisTokBuf[0] != '(')
1416  ++ThisTokBuf;
1417  ++ThisTokBuf; // skip '('
1418 
1419  // Remove same number of characters from the end
1420  ThisTokEnd -= ThisTokBuf - Prefix;
1421  assert(ThisTokEnd >= ThisTokBuf && "malformed raw string literal");
1422 
1423  // Copy the string over
1424  if (CopyStringFragment(StringToks[i], ThisTokBegin,
1425  StringRef(ThisTokBuf, ThisTokEnd - ThisTokBuf)))
1426  hadError = true;
1427  } else {
1428  if (ThisTokBuf[0] != '"') {
1429  // The file may have come from PCH and then changed after loading the
1430  // PCH; Fail gracefully.
1431  return DiagnoseLexingError(StringToks[i].getLocation());
1432  }
1433  ++ThisTokBuf; // skip "
1434 
1435  // Check if this is a pascal string
1436  if (Features.PascalStrings && ThisTokBuf + 1 != ThisTokEnd &&
1437  ThisTokBuf[0] == '\\' && ThisTokBuf[1] == 'p') {
1438 
1439  // If the \p sequence is found in the first token, we have a pascal string
1440  // Otherwise, if we already have a pascal string, ignore the first \p
1441  if (i == 0) {
1442  ++ThisTokBuf;
1443  Pascal = true;
1444  } else if (Pascal)
1445  ThisTokBuf += 2;
1446  }
1447 
1448  while (ThisTokBuf != ThisTokEnd) {
1449  // Is this a span of non-escape characters?
1450  if (ThisTokBuf[0] != '\\') {
1451  const char *InStart = ThisTokBuf;
1452  do {
1453  ++ThisTokBuf;
1454  } while (ThisTokBuf != ThisTokEnd && ThisTokBuf[0] != '\\');
1455 
1456  // Copy the character span over.
1457  if (CopyStringFragment(StringToks[i], ThisTokBegin,
1458  StringRef(InStart, ThisTokBuf - InStart)))
1459  hadError = true;
1460  continue;
1461  }
1462  // Is this a Universal Character Name escape?
1463  if (ThisTokBuf[1] == 'u' || ThisTokBuf[1] == 'U') {
1464  EncodeUCNEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd,
1465  ResultPtr, hadError,
1466  FullSourceLoc(StringToks[i].getLocation(), SM),
1467  CharByteWidth, Diags, Features);
1468  continue;
1469  }
1470  // Otherwise, this is a non-UCN escape character. Process it.
1471  unsigned ResultChar =
1472  ProcessCharEscape(ThisTokBegin, ThisTokBuf, ThisTokEnd, hadError,
1473  FullSourceLoc(StringToks[i].getLocation(), SM),
1474  CharByteWidth*8, Diags, Features);
1475 
1476  if (CharByteWidth == 4) {
1477  // FIXME: Make the type of the result buffer correct instead of
1478  // using reinterpret_cast.
1479  UTF32 *ResultWidePtr = reinterpret_cast<UTF32*>(ResultPtr);
1480  *ResultWidePtr = ResultChar;
1481  ResultPtr += 4;
1482  } else if (CharByteWidth == 2) {
1483  // FIXME: Make the type of the result buffer correct instead of
1484  // using reinterpret_cast.
1485  UTF16 *ResultWidePtr = reinterpret_cast<UTF16*>(ResultPtr);
1486  *ResultWidePtr = ResultChar & 0xFFFF;
1487  ResultPtr += 2;
1488  } else {
1489  assert(CharByteWidth == 1 && "Unexpected char width");
1490  *ResultPtr++ = ResultChar & 0xFF;
1491  }
1492  }
1493  }
1494  }
1495 
1496  if (Pascal) {
1497  if (CharByteWidth == 4) {
1498  // FIXME: Make the type of the result buffer correct instead of
1499  // using reinterpret_cast.
1500  UTF32 *ResultWidePtr = reinterpret_cast<UTF32*>(ResultBuf.data());
1501  ResultWidePtr[0] = GetNumStringChars() - 1;
1502  } else if (CharByteWidth == 2) {
1503  // FIXME: Make the type of the result buffer correct instead of
1504  // using reinterpret_cast.
1505  UTF16 *ResultWidePtr = reinterpret_cast<UTF16*>(ResultBuf.data());
1506  ResultWidePtr[0] = GetNumStringChars() - 1;
1507  } else {
1508  assert(CharByteWidth == 1 && "Unexpected char width");
1509  ResultBuf[0] = GetNumStringChars() - 1;
1510  }
1511 
1512  // Verify that pascal strings aren't too large.
1513  if (GetStringLength() > 256) {
1514  if (Diags)
1515  Diags->Report(StringToks.front().getLocation(),
1516  diag::err_pascal_string_too_long)
1517  << SourceRange(StringToks.front().getLocation(),
1518  StringToks.back().getLocation());
1519  hadError = true;
1520  return;
1521  }
1522  } else if (Diags) {
1523  // Complain if this string literal has too many characters.
1524  unsigned MaxChars = Features.CPlusPlus? 65536 : Features.C99 ? 4095 : 509;
1525 
1526  if (GetNumStringChars() > MaxChars)
1527  Diags->Report(StringToks.front().getLocation(),
1528  diag::ext_string_too_long)
1529  << GetNumStringChars() << MaxChars
1530  << (Features.CPlusPlus ? 2 : Features.C99 ? 1 : 0)
1531  << SourceRange(StringToks.front().getLocation(),
1532  StringToks.back().getLocation());
1533  }
1534 }
1535 
1536 static const char *resyncUTF8(const char *Err, const char *End) {
1537  if (Err == End)
1538  return End;
1539  End = Err + std::min<unsigned>(getNumBytesForUTF8(*Err), End-Err);
1540  while (++Err != End && (*Err & 0xC0) == 0x80)
1541  ;
1542  return Err;
1543 }
1544 
1545 /// \brief This function copies from Fragment, which is a sequence of bytes
1546 /// within Tok's contents (which begin at TokBegin) into ResultPtr.
1547 /// Performs widening for multi-byte characters.
1548 bool StringLiteralParser::CopyStringFragment(const Token &Tok,
1549  const char *TokBegin,
1550  StringRef Fragment) {
1551  const UTF8 *ErrorPtrTmp;
1552  if (ConvertUTF8toWide(CharByteWidth, Fragment, ResultPtr, ErrorPtrTmp))
1553  return false;
1554 
1555  // If we see bad encoding for unprefixed string literals, warn and
1556  // simply copy the byte values, for compatibility with gcc and older
1557  // versions of clang.
1558  bool NoErrorOnBadEncoding = isAscii();
1559  if (NoErrorOnBadEncoding) {
1560  memcpy(ResultPtr, Fragment.data(), Fragment.size());
1561  ResultPtr += Fragment.size();
1562  }
1563 
1564  if (Diags) {
1565  const char *ErrorPtr = reinterpret_cast<const char *>(ErrorPtrTmp);
1566 
1567  FullSourceLoc SourceLoc(Tok.getLocation(), SM);
1568  const DiagnosticBuilder &Builder =
1569  Diag(Diags, Features, SourceLoc, TokBegin,
1570  ErrorPtr, resyncUTF8(ErrorPtr, Fragment.end()),
1571  NoErrorOnBadEncoding ? diag::warn_bad_string_encoding
1572  : diag::err_bad_string_encoding);
1573 
1574  const char *NextStart = resyncUTF8(ErrorPtr, Fragment.end());
1575  StringRef NextFragment(NextStart, Fragment.end()-NextStart);
1576 
1577  // Decode into a dummy buffer.
1578  SmallString<512> Dummy;
1579  Dummy.reserve(Fragment.size() * CharByteWidth);
1580  char *Ptr = Dummy.data();
1581 
1582  while (!ConvertUTF8toWide(CharByteWidth, NextFragment, Ptr, ErrorPtrTmp)) {
1583  const char *ErrorPtr = reinterpret_cast<const char *>(ErrorPtrTmp);
1584  NextStart = resyncUTF8(ErrorPtr, Fragment.end());
1585  Builder << MakeCharSourceRange(Features, SourceLoc, TokBegin,
1586  ErrorPtr, NextStart);
1587  NextFragment = StringRef(NextStart, Fragment.end()-NextStart);
1588  }
1589  }
1590  return !NoErrorOnBadEncoding;
1591 }
1592 
1593 void StringLiteralParser::DiagnoseLexingError(SourceLocation Loc) {
1594  hadError = true;
1595  if (Diags)
1596  Diags->Report(Loc, diag::err_lexing_string);
1597 }
1598 
1599 /// getOffsetOfStringByte - This function returns the offset of the
1600 /// specified byte of the string data represented by Token. This handles
1601 /// advancing over escape sequences in the string.
1603  unsigned ByteNo) const {
1604  // Get the spelling of the token.
1605  SmallString<32> SpellingBuffer;
1606  SpellingBuffer.resize(Tok.getLength());
1607 
1608  bool StringInvalid = false;
1609  const char *SpellingPtr = &SpellingBuffer[0];
1610  unsigned TokLen = Lexer::getSpelling(Tok, SpellingPtr, SM, Features,
1611  &StringInvalid);
1612  if (StringInvalid)
1613  return 0;
1614 
1615  const char *SpellingStart = SpellingPtr;
1616  const char *SpellingEnd = SpellingPtr+TokLen;
1617 
1618  // Handle UTF-8 strings just like narrow strings.
1619  if (SpellingPtr[0] == 'u' && SpellingPtr[1] == '8')
1620  SpellingPtr += 2;
1621 
1622  assert(SpellingPtr[0] != 'L' && SpellingPtr[0] != 'u' &&
1623  SpellingPtr[0] != 'U' && "Doesn't handle wide or utf strings yet");
1624 
1625  // For raw string literals, this is easy.
1626  if (SpellingPtr[0] == 'R') {
1627  assert(SpellingPtr[1] == '"' && "Should be a raw string literal!");
1628  // Skip 'R"'.
1629  SpellingPtr += 2;
1630  while (*SpellingPtr != '(') {
1631  ++SpellingPtr;
1632  assert(SpellingPtr < SpellingEnd && "Missing ( for raw string literal");
1633  }
1634  // Skip '('.
1635  ++SpellingPtr;
1636  return SpellingPtr - SpellingStart + ByteNo;
1637  }
1638 
1639  // Skip over the leading quote
1640  assert(SpellingPtr[0] == '"' && "Should be a string literal!");
1641  ++SpellingPtr;
1642 
1643  // Skip over bytes until we find the offset we're looking for.
1644  while (ByteNo) {
1645  assert(SpellingPtr < SpellingEnd && "Didn't find byte offset!");
1646 
1647  // Step over non-escapes simply.
1648  if (*SpellingPtr != '\\') {
1649  ++SpellingPtr;
1650  --ByteNo;
1651  continue;
1652  }
1653 
1654  // Otherwise, this is an escape character. Advance over it.
1655  bool HadError = false;
1656  if (SpellingPtr[1] == 'u' || SpellingPtr[1] == 'U') {
1657  const char *EscapePtr = SpellingPtr;
1658  unsigned Len = MeasureUCNEscape(SpellingStart, SpellingPtr, SpellingEnd,
1659  1, Features, HadError);
1660  if (Len > ByteNo) {
1661  // ByteNo is somewhere within the escape sequence.
1662  SpellingPtr = EscapePtr;
1663  break;
1664  }
1665  ByteNo -= Len;
1666  } else {
1667  ProcessCharEscape(SpellingStart, SpellingPtr, SpellingEnd, HadError,
1668  FullSourceLoc(Tok.getLocation(), SM),
1669  CharByteWidth*8, Diags, Features);
1670  --ByteNo;
1671  }
1672  assert(!HadError && "This method isn't valid on erroneous strings");
1673  }
1674 
1675  return SpellingPtr-SpellingStart;
1676 }
SourceManager & getSourceManager() const
Definition: Preprocessor.h:682
static unsigned getSpelling(const Token &Tok, const char *&Buffer, const SourceManager &SourceMgr, const LangOptions &LangOpts, bool *Invalid=nullptr)
Definition: Lexer.cpp:358
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
static LLVM_READONLY bool isDigit(unsigned char c)
Return true if this character is an ASCII digit: [0-9].
Definition: CharInfo.h:94
StringLiteralParser(ArrayRef< Token > StringToks, Preprocessor &PP, bool Complain=true)
const SourceManager & getManager() const
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1118
static LLVM_READONLY bool isPreprocessingNumberBody(unsigned char c)
Definition: CharInfo.h:148
static bool alwaysFitsInto64Bits(unsigned Radix, unsigned NumDigits)
unsigned getOffsetOfStringByte(const Token &TheTok, unsigned ByteNo) const
const LangOptions & getLangOpts() const
Definition: Preprocessor.h:679
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:48
static int MeasureUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf, const char *ThisTokEnd, unsigned CharByteWidth, const LangOptions &Features, bool &HadError)
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:135
static bool isValidUDSuffix(const LangOptions &LangOpts, StringRef Suffix)
NumericLiteralParser(StringRef TokSpelling, SourceLocation TokLoc, Preprocessor &PP)
SourceLocation AdvanceToTokenCharacter(SourceLocation TokStart, unsigned Char) const
Given a location that specifies the start of a token, return a new location that specifies a characte...
const TargetInfo & getTargetInfo() const
Definition: Preprocessor.h:680
static SourceLocation AdvanceToTokenCharacter(SourceLocation TokStart, unsigned Character, const SourceManager &SM, const LangOptions &LangOpts)
Definition: Lexer.cpp:700
DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) const
A little helper class used to produce diagnostics.
Definition: Diagnostic.h:866
const SmallVectorImpl< AnnotatedLine * >::const_iterator End
SourceManager & SM
Exposes information about the current target.
CharLiteralParser(const char *begin, const char *end, SourceLocation Loc, Preprocessor &PP, tok::TokenKind kind)
Represents a character-granular source range.
Defines the clang::Preprocessor interface.
static const char * resyncUTF8(const char *Err, const char *End)
SourceLocation getLocation() const
Return a source location identifier for the specified offset in the current file. ...
Definition: Token.h:124
static void appendCodePoint(unsigned Codepoint, llvm::SmallVectorImpl< char > &Str)
static CharSourceRange getCharRange(SourceRange R)
bool GetIntegerValue(llvm::APInt &Val)
#define false
Definition: stdbool.h:33
Kind
Encodes a location in the source. The SourceManager can decode this to get at the full include stack...
llvm::APFloat::opStatus GetFloatValue(llvm::APFloat &Result)
static unsigned ProcessCharEscape(const char *ThisTokBegin, const char *&ThisTokBuf, const char *ThisTokEnd, bool &HadError, FullSourceLoc Loc, unsigned CharWidth, DiagnosticsEngine *Diags, const LangOptions &Features)
TokenKind
Provides a simple uniform namespace for tokens from all C languages.
Definition: TokenKinds.h:25
void expandUCNs(SmallVectorImpl< char > &Buf, StringRef Input)
Copy characters from Input to Buf, expanding any UCNs.
DiagnosticsEngine & getDiagnostics() const
Definition: Preprocessor.h:676
static void EncodeUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf, const char *ThisTokEnd, char *&ResultBuf, bool &HadError, FullSourceLoc Loc, unsigned CharByteWidth, DiagnosticsEngine *Diags, const LangOptions &Features)
static LLVM_READONLY bool isPrintable(unsigned char c)
Definition: CharInfo.h:140
BoundNodesTreeBuilder *const Builder
static unsigned getCharWidth(tok::TokenKind kind, const TargetInfo &Target)
unsigned kind
All of the diagnostics that can be emitted by the frontend.
Definition: DiagnosticIDs.h:43
const StringRef Input
Defines the clang::TargetInfo interface.
unsigned GetStringLength() const
A SourceLocation and its associated SourceManager.
unsigned getLength() const
Definition: Token.h:127
A trivial tuple used to represent a source range.
unsigned GetNumStringChars() const
static bool ProcessUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf, const char *ThisTokEnd, uint32_t &UcnVal, unsigned short &UcnLen, FullSourceLoc Loc, DiagnosticsEngine *Diags, const LangOptions &Features, bool in_char_string_literal=false)
static CharSourceRange MakeCharSourceRange(const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd)
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:96
static LLVM_READONLY bool isHexDigit(unsigned char c)
Return true if this character is an ASCII hex digit: [0-9a-fA-F].
Definition: CharInfo.h:124