Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
//== PrintfFormatString.cpp - Analysis of printf format strings --*- C++ -*-==//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Handling of format string in printf and friends.  The structure of format
// strings for fprintf() are described in C99 7.19.6.1.
//
//===----------------------------------------------------------------------===//

#include "clang/Analysis/Analyses/FormatString.h"
#include "FormatStringParsing.h"
#include "clang/Basic/TargetInfo.h"

using clang::analyze_format_string::ArgType;
using clang::analyze_format_string::FormatStringHandler;
using clang::analyze_format_string::LengthModifier;
using clang::analyze_format_string::OptionalAmount;
using clang::analyze_format_string::ConversionSpecifier;
using clang::analyze_printf::PrintfSpecifier;

using namespace clang;

typedef clang::analyze_format_string::SpecifierResult<PrintfSpecifier>
        PrintfSpecifierResult;

//===----------------------------------------------------------------------===//
// Methods for parsing format strings.
//===----------------------------------------------------------------------===//

using analyze_format_string::ParseNonPositionAmount;

static bool ParsePrecision(FormatStringHandler &H, PrintfSpecifier &FS,
                           const char *Start, const char *&Beg, const char *E,
                           unsigned *argIndex) {
  if (argIndex) {
    FS.setPrecision(ParseNonPositionAmount(Beg, E, *argIndex));
  } else {
    const OptionalAmount Amt = ParsePositionAmount(H, Start, Beg, E,
                                           analyze_format_string::PrecisionPos);
    if (Amt.isInvalid())
      return true;
    FS.setPrecision(Amt);
  }
  return false;
}

static bool ParseObjCFlags(FormatStringHandler &H, PrintfSpecifier &FS,
                           const char *FlagBeg, const char *E, bool Warn) {
   StringRef Flag(FlagBeg, E - FlagBeg);
   // Currently there is only one flag.
   if (Flag == "tt") {
     FS.setHasObjCTechnicalTerm(FlagBeg);
     return false;
   }
   // Handle either the case of no flag or an invalid flag.
   if (Warn) {
     if (Flag == "")
       H.HandleEmptyObjCModifierFlag(FlagBeg, E  - FlagBeg);
     else
       H.HandleInvalidObjCModifierFlag(FlagBeg, E  - FlagBeg);
   }
   return true;
}

static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
                                                  const char *&Beg,
                                                  const char *E,
                                                  unsigned &argIndex,
                                                  const LangOptions &LO,
                                                  const TargetInfo &Target,
                                                  bool Warn,
                                                  bool isFreeBSDKPrintf) {

  using namespace clang::analyze_format_string;
  using namespace clang::analyze_printf;

  const char *I = Beg;
  const char *Start = nullptr;
  UpdateOnReturn <const char*> UpdateBeg(Beg, I);

  // Look for a '%' character that indicates the start of a format specifier.
  for ( ; I != E ; ++I) {
    char c = *I;
    if (c == '\0') {
      // Detect spurious null characters, which are likely errors.
      H.HandleNullChar(I);
      return true;
    }
    if (c == '%') {
      Start = I++;  // Record the start of the format specifier.
      break;
    }
  }

  // No format specifier found?
  if (!Start)
    return false;

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  PrintfSpecifier FS;
  if (ParseArgPosition(H, FS, Start, I, E))
    return true;

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  const char *OSLogVisibilityFlagsStart = nullptr,
             *OSLogVisibilityFlagsEnd = nullptr;
  if (*I == '{') {
    OSLogVisibilityFlagsStart = I++;
    // Find the end of the modifier.
    while (I != E && *I != '}') {
      I++;
    }
    if (I == E) {
      if (Warn)
        H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }
    assert(*I == '}');
    OSLogVisibilityFlagsEnd = I++;

    // Just see if 'private' or 'public' is the first word. os_log itself will
    // do any further parsing.
    const char *P = OSLogVisibilityFlagsStart + 1;
    while (P < OSLogVisibilityFlagsEnd && isspace(*P))
      P++;
    const char *WordStart = P;
    while (P < OSLogVisibilityFlagsEnd && (isalnum(*P) || *P == '_'))
      P++;
    const char *WordEnd = P;
    StringRef Word(WordStart, WordEnd - WordStart);
    if (Word == "private") {
      FS.setIsPrivate(WordStart);
    } else if (Word == "public") {
      FS.setIsPublic(WordStart);
    }
  }

  // Look for flags (if any).
  bool hasMore = true;
  for ( ; I != E; ++I) {
    switch (*I) {
      default: hasMore = false; break;
      case '\'':
        // FIXME: POSIX specific.  Always accept?
        FS.setHasThousandsGrouping(I);
        break;
      case '-': FS.setIsLeftJustified(I); break;
      case '+': FS.setHasPlusPrefix(I); break;
      case ' ': FS.setHasSpacePrefix(I); break;
      case '#': FS.setHasAlternativeForm(I); break;
      case '0': FS.setHasLeadingZeros(I); break;
    }
    if (!hasMore)
      break;
  }

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the field width (if any).
  if (ParseFieldWidth(H, FS, Start, I, E,
                      FS.usesPositionalArg() ? nullptr : &argIndex))
    return true;

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the precision (if any).
  if (*I == '.') {
    ++I;
    if (I == E) {
      if (Warn)
        H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }

    if (ParsePrecision(H, FS, Start, I, E,
                       FS.usesPositionalArg() ? nullptr : &argIndex))
      return true;

    if (I == E) {
      // No more characters left?
      if (Warn)
        H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }
  }

  // Look for the length modifier.
  if (ParseLengthModifier(FS, I, E, LO) && I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the Objective-C modifier flags, if any.
  // We parse these here, even if they don't apply to
  // the conversion specifier, and then emit an error
  // later if the conversion specifier isn't '@'.  This
  // enables better recovery, and we don't know if
  // these flags are applicable until later.
  const char *ObjCModifierFlagsStart = nullptr,
             *ObjCModifierFlagsEnd = nullptr;
  if (*I == '[') {
    ObjCModifierFlagsStart = I;
    ++I;
    auto flagStart = I;
    for (;; ++I) {
      ObjCModifierFlagsEnd = I;
      if (I == E) {
        if (Warn)
          H.HandleIncompleteSpecifier(Start, E - Start);
        return true;
      }
      // Did we find the closing ']'?
      if (*I == ']') {
        if (ParseObjCFlags(H, FS, flagStart, I, Warn))
          return true;
        ++I;
        break;
      }
      // There are no separators defined yet for multiple
      // Objective-C modifier flags.  When those are
      // defined, this is the place to check.
    }
  }

  if (*I == '\0') {
    // Detect spurious null characters, which are likely errors.
    H.HandleNullChar(I);
    return true;
  }

  // Finally, look for the conversion specifier.
  const char *conversionPosition = I++;
  ConversionSpecifier::Kind k = ConversionSpecifier::InvalidSpecifier;
  switch (*conversionPosition) {
    default:
      break;
    // C99: 7.19.6.1 (section 8).
    case '%': k = ConversionSpecifier::PercentArg;   break;
    case 'A': k = ConversionSpecifier::AArg; break;
    case 'E': k = ConversionSpecifier::EArg; break;
    case 'F': k = ConversionSpecifier::FArg; break;
    case 'G': k = ConversionSpecifier::GArg; break;
    case 'X': k = ConversionSpecifier::XArg; break;
    case 'a': k = ConversionSpecifier::aArg; break;
    case 'c': k = ConversionSpecifier::cArg; break;
    case 'd': k = ConversionSpecifier::dArg; break;
    case 'e': k = ConversionSpecifier::eArg; break;
    case 'f': k = ConversionSpecifier::fArg; break;
    case 'g': k = ConversionSpecifier::gArg; break;
    case 'i': k = ConversionSpecifier::iArg; break;
    case 'n': k = ConversionSpecifier::nArg; break;
    case 'o': k = ConversionSpecifier::oArg; break;
    case 'p': k = ConversionSpecifier::pArg; break;
    case 's': k = ConversionSpecifier::sArg; break;
    case 'u': k = ConversionSpecifier::uArg; break;
    case 'x': k = ConversionSpecifier::xArg; break;
    // POSIX specific.
    case 'C': k = ConversionSpecifier::CArg; break;
    case 'S': k = ConversionSpecifier::SArg; break;
    // Apple extension for os_log
    case 'P':
      k = ConversionSpecifier::PArg;
      break;
    // Objective-C.
    case '@': k = ConversionSpecifier::ObjCObjArg; break;
    // Glibc specific.
    case 'm': k = ConversionSpecifier::PrintErrno; break;
    // FreeBSD kernel specific.
    case 'b':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDbArg; // int followed by char *
      break;
    case 'r':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDrArg; // int
      break;
    case 'y':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDyArg; // int
      break;
    // Apple-specific.
    case 'D':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDDArg; // void * followed by char *
      else if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::DArg;
      break;
    case 'O':
      if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::OArg;
      break;
    case 'U':
      if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::UArg;
      break;
    // MS specific.
    case 'Z':
      if (Target.getTriple().isOSMSVCRT())
        k = ConversionSpecifier::ZArg;
  }
  
  // Check to see if we used the Objective-C modifier flags with
  // a conversion specifier other than '@'.
  if (k != ConversionSpecifier::ObjCObjArg &&
      k != ConversionSpecifier::InvalidSpecifier &&
      ObjCModifierFlagsStart) {
    H.HandleObjCFlagsWithNonObjCConversion(ObjCModifierFlagsStart,
                                           ObjCModifierFlagsEnd + 1,
                                           conversionPosition);
    return true;
  }

  PrintfConversionSpecifier CS(conversionPosition, k);
  FS.setConversionSpecifier(CS);
  if (CS.consumesDataArgument() && !FS.usesPositionalArg())
    FS.setArgIndex(argIndex++);
  // FreeBSD kernel specific.
  if (k == ConversionSpecifier::FreeBSDbArg ||
      k == ConversionSpecifier::FreeBSDDArg)
    argIndex++;

  if (k == ConversionSpecifier::InvalidSpecifier) {
    unsigned Len = I - Start;
    if (ParseUTF8InvalidSpecifier(Start, E, Len)) {
      CS.setEndScanList(Start + Len);
      FS.setConversionSpecifier(CS);
    }
    // Assume the conversion takes one argument.
    return !H.HandleInvalidPrintfConversionSpecifier(FS, Start, Len);
  }
  return PrintfSpecifierResult(Start, FS);
}

bool clang::analyze_format_string::ParsePrintfString(FormatStringHandler &H,
                                                     const char *I,
                                                     const char *E,
                                                     const LangOptions &LO,
                                                     const TargetInfo &Target,
                                                     bool isFreeBSDKPrintf) {

  unsigned argIndex = 0;

  // Keep looking for a format specifier until we have exhausted the string.
  while (I != E) {
    const PrintfSpecifierResult &FSR = ParsePrintfSpecifier(H, I, E, argIndex,
                                                            LO, Target, true,
                                                            isFreeBSDKPrintf);
    // Did a fail-stop error of any kind occur when parsing the specifier?
    // If so, don't do any more processing.
    if (FSR.shouldStop())
      return true;
    // Did we exhaust the string or encounter an error that
    // we can recover from?
    if (!FSR.hasValue())
      continue;
    // We have a format specifier.  Pass it to the callback.
    if (!H.HandlePrintfSpecifier(FSR.getValue(), FSR.getStart(),
                                 I - FSR.getStart()))
      return true;
  }
  assert(I == E && "Format string not exhausted");
  return false;
}

bool clang::analyze_format_string::ParseFormatStringHasSArg(const char *I,
                                                            const char *E,
                                                            const LangOptions &LO,
                                                            const TargetInfo &Target) {
  
  unsigned argIndex = 0;
  
  // Keep looking for a %s format specifier until we have exhausted the string.
  FormatStringHandler H;
  while (I != E) {
    const PrintfSpecifierResult &FSR = ParsePrintfSpecifier(H, I, E, argIndex,
                                                            LO, Target, false,
                                                            false);
    // Did a fail-stop error of any kind occur when parsing the specifier?
    // If so, don't do any more processing.
    if (FSR.shouldStop())
      return false;
    // Did we exhaust the string or encounter an error that
    // we can recover from?
    if (!FSR.hasValue())
      continue;
    const analyze_printf::PrintfSpecifier &FS = FSR.getValue();
    // Return true if this a %s format specifier.
    if (FS.getConversionSpecifier().getKind() == ConversionSpecifier::Kind::sArg)
      return true;
  }
  return false;
}

//===----------------------------------------------------------------------===//
// Methods on PrintfSpecifier.
//===----------------------------------------------------------------------===//

ArgType PrintfSpecifier::getArgType(ASTContext &Ctx,
                                    bool IsObjCLiteral) const {
  const PrintfConversionSpecifier &CS = getConversionSpecifier();

  if (!CS.consumesDataArgument())
    return ArgType::Invalid();

  if (CS.getKind() == ConversionSpecifier::cArg)
    switch (LM.getKind()) {
      case LengthModifier::None:
        return Ctx.IntTy;
      case LengthModifier::AsLong:
      case LengthModifier::AsWide:
        return ArgType(ArgType::WIntTy, "wint_t");
      case LengthModifier::AsShort:
        if (Ctx.getTargetInfo().getTriple().isOSMSVCRT())
          return Ctx.IntTy;
        LLVM_FALLTHROUGH;
      default:
        return ArgType::Invalid();
    }

  if (CS.isIntArg())
    switch (LM.getKind()) {
      case LengthModifier::AsLongDouble:
        // GNU extension.
        return Ctx.LongLongTy;
      case LengthModifier::None:
        return Ctx.IntTy;
      case LengthModifier::AsInt32:
        return ArgType(Ctx.IntTy, "__int32");
      case LengthModifier::AsChar: return ArgType::AnyCharTy;
      case LengthModifier::AsShort: return Ctx.ShortTy;
      case LengthModifier::AsLong: return Ctx.LongTy;
      case LengthModifier::AsLongLong:
      case LengthModifier::AsQuad:
        return Ctx.LongLongTy;
      case LengthModifier::AsInt64:
        return ArgType(Ctx.LongLongTy, "__int64");
      case LengthModifier::AsIntMax:
        return ArgType(Ctx.getIntMaxType(), "intmax_t");
      case LengthModifier::AsSizeT:
        return ArgType(Ctx.getSignedSizeType(), "ssize_t");
      case LengthModifier::AsInt3264:
        return Ctx.getTargetInfo().getTriple().isArch64Bit()
                   ? ArgType(Ctx.LongLongTy, "__int64")
                   : ArgType(Ctx.IntTy, "__int32");
      case LengthModifier::AsPtrDiff:
        return ArgType(Ctx.getPointerDiffType(), "ptrdiff_t");
      case LengthModifier::AsAllocate:
      case LengthModifier::AsMAllocate:
      case LengthModifier::AsWide:
        return ArgType::Invalid();
    }

  if (CS.isUIntArg())
    switch (LM.getKind()) {
      case LengthModifier::AsLongDouble:
        // GNU extension.
        return Ctx.UnsignedLongLongTy;
      case LengthModifier::None:
        return Ctx.UnsignedIntTy;
      case LengthModifier::AsInt32:
        return ArgType(Ctx.UnsignedIntTy, "unsigned __int32");
      case LengthModifier::AsChar: return Ctx.UnsignedCharTy;
      case LengthModifier::AsShort: return Ctx.UnsignedShortTy;
      case LengthModifier::AsLong: return Ctx.UnsignedLongTy;
      case LengthModifier::AsLongLong:
      case LengthModifier::AsQuad:
        return Ctx.UnsignedLongLongTy;
      case LengthModifier::AsInt64:
        return ArgType(Ctx.UnsignedLongLongTy, "unsigned __int64");
      case LengthModifier::AsIntMax:
        return ArgType(Ctx.getUIntMaxType(), "uintmax_t");
      case LengthModifier::AsSizeT:
        return ArgType(Ctx.getSizeType(), "size_t");
      case LengthModifier::AsInt3264:
        return Ctx.getTargetInfo().getTriple().isArch64Bit()
                   ? ArgType(Ctx.UnsignedLongLongTy, "unsigned __int64")
                   : ArgType(Ctx.UnsignedIntTy, "unsigned __int32");
      case LengthModifier::AsPtrDiff:
        return ArgType(Ctx.getUnsignedPointerDiffType(), "unsigned ptrdiff_t");
      case LengthModifier::AsAllocate:
      case LengthModifier::AsMAllocate:
      case LengthModifier::AsWide:
        return ArgType::Invalid();
    }

  if (CS.isDoubleArg()) {
    if (LM.getKind() == LengthModifier::AsLongDouble)
      return Ctx.LongDoubleTy;
    return Ctx.DoubleTy;
  }

  if (CS.getKind() == ConversionSpecifier::nArg) {
    switch (LM.getKind()) {
      case LengthModifier::None:
        return ArgType::PtrTo(Ctx.IntTy);
      case LengthModifier::AsChar:
        return ArgType::PtrTo(Ctx.SignedCharTy);
      case LengthModifier::AsShort:
        return ArgType::PtrTo(Ctx.ShortTy);
      case LengthModifier::AsLong:
        return ArgType::PtrTo(Ctx.LongTy);
      case LengthModifier::AsLongLong:
      case LengthModifier::AsQuad:
        return ArgType::PtrTo(Ctx.LongLongTy);
      case LengthModifier::AsIntMax:
        return ArgType::PtrTo(ArgType(Ctx.getIntMaxType(), "intmax_t"));
      case LengthModifier::AsSizeT:
        return ArgType::PtrTo(ArgType(Ctx.getSignedSizeType(), "ssize_t"));
      case LengthModifier::AsPtrDiff:
        return ArgType::PtrTo(ArgType(Ctx.getPointerDiffType(), "ptrdiff_t"));
      case LengthModifier::AsLongDouble:
        return ArgType(); // FIXME: Is this a known extension?
      case LengthModifier::AsAllocate:
      case LengthModifier::AsMAllocate:
      case LengthModifier::AsInt32:
      case LengthModifier::AsInt3264:
      case LengthModifier::AsInt64:
      case LengthModifier::AsWide:
        return ArgType::Invalid();
    }
  }

  switch (CS.getKind()) {
    case ConversionSpecifier::sArg:
      if (LM.getKind() == LengthModifier::AsWideChar) {
        if (IsObjCLiteral)
          return ArgType(Ctx.getPointerType(Ctx.UnsignedShortTy.withConst()),
                         "const unichar *");
        return ArgType(ArgType::WCStrTy, "wchar_t *");
      }
      if (LM.getKind() == LengthModifier::AsWide)
        return ArgType(ArgType::WCStrTy, "wchar_t *");
      return ArgType::CStrTy;
    case ConversionSpecifier::SArg:
      if (IsObjCLiteral)
        return ArgType(Ctx.getPointerType(Ctx.UnsignedShortTy.withConst()),
                       "const unichar *");
      if (Ctx.getTargetInfo().getTriple().isOSMSVCRT() &&
          LM.getKind() == LengthModifier::AsShort)
        return ArgType::CStrTy;
      return ArgType(ArgType::WCStrTy, "wchar_t *");
    case ConversionSpecifier::CArg:
      if (IsObjCLiteral)
        return ArgType(Ctx.UnsignedShortTy, "unichar");
      if (Ctx.getTargetInfo().getTriple().isOSMSVCRT() &&
          LM.getKind() == LengthModifier::AsShort)
        return Ctx.IntTy;
      return ArgType(Ctx.WideCharTy, "wchar_t");
    case ConversionSpecifier::pArg:
    case ConversionSpecifier::PArg:
      return ArgType::CPointerTy;
    case ConversionSpecifier::ObjCObjArg:
      return ArgType::ObjCPointerTy;
    default:
      break;
  }

  // FIXME: Handle other cases.
  return ArgType();
}

bool PrintfSpecifier::fixType(QualType QT, const LangOptions &LangOpt,
                              ASTContext &Ctx, bool IsObjCLiteral) {
  // %n is different from other conversion specifiers; don't try to fix it.
  if (CS.getKind() == ConversionSpecifier::nArg)
    return false;

  // Handle Objective-C objects first. Note that while the '%@' specifier will
  // not warn for structure pointer or void pointer arguments (because that's
  // how CoreFoundation objects are implemented), we only show a fixit for '%@'
  // if we know it's an object (block, id, class, or __attribute__((NSObject))).
  if (QT->isObjCRetainableType()) {
    if (!IsObjCLiteral)
      return false;

    CS.setKind(ConversionSpecifier::ObjCObjArg);

    // Disable irrelevant flags
    HasThousandsGrouping = false;
    HasPlusPrefix = false;
    HasSpacePrefix = false;
    HasAlternativeForm = false;
    HasLeadingZeroes = false;
    Precision.setHowSpecified(OptionalAmount::NotSpecified);
    LM.setKind(LengthModifier::None);

    return true;
  }

  // Handle strings next (char *, wchar_t *)
  if (QT->isPointerType() && (QT->getPointeeType()->isAnyCharacterType())) {
    CS.setKind(ConversionSpecifier::sArg);

    // Disable irrelevant flags
    HasAlternativeForm = 0;
    HasLeadingZeroes = 0;

    // Set the long length modifier for wide characters
    if (QT->getPointeeType()->isWideCharType())
      LM.setKind(LengthModifier::AsWideChar);
    else
      LM.setKind(LengthModifier::None);

    return true;
  }

  // If it's an enum, get its underlying type.
  if (const EnumType *ETy = QT->getAs<EnumType>())
    QT = ETy->getDecl()->getIntegerType();

  // We can only work with builtin types.
  const BuiltinType *BT = QT->getAs<BuiltinType>();
  if (!BT)
    return false;

  // Set length modifier
  switch (BT->getKind()) {
  case BuiltinType::Bool:
  case BuiltinType::WChar_U:
  case BuiltinType::WChar_S:
  case BuiltinType::Char16:
  case BuiltinType::Char32:
  case BuiltinType::UInt128:
  case BuiltinType::Int128:
  case BuiltinType::Half:
  case BuiltinType::Float16:
  case BuiltinType::Float128:
    // Various types which are non-trivial to correct.
    return false;

#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
  case BuiltinType::Id:
#include "clang/Basic/OpenCLImageTypes.def"
#define SIGNED_TYPE(Id, SingletonId)
#define UNSIGNED_TYPE(Id, SingletonId)
#define FLOATING_TYPE(Id, SingletonId)
#define BUILTIN_TYPE(Id, SingletonId) \
  case BuiltinType::Id:
#include "clang/AST/BuiltinTypes.def"
    // Misc other stuff which doesn't make sense here.
    return false;

  case BuiltinType::UInt:
  case BuiltinType::Int:
  case BuiltinType::Float:
  case BuiltinType::Double:
    LM.setKind(LengthModifier::None);
    break;

  case BuiltinType::Char_U:
  case BuiltinType::UChar:
  case BuiltinType::Char_S:
  case BuiltinType::SChar:
    LM.setKind(LengthModifier::AsChar);
    break;

  case BuiltinType::Short:
  case BuiltinType::UShort:
    LM.setKind(LengthModifier::AsShort);
    break;

  case BuiltinType::Long:
  case BuiltinType::ULong:
    LM.setKind(LengthModifier::AsLong);
    break;

  case BuiltinType::LongLong:
  case BuiltinType::ULongLong:
    LM.setKind(LengthModifier::AsLongLong);
    break;

  case BuiltinType::LongDouble:
    LM.setKind(LengthModifier::AsLongDouble);
    break;
  }

  // Handle size_t, ptrdiff_t, etc. that have dedicated length modifiers in C99.
  if (isa<TypedefType>(QT) && (LangOpt.C99 || LangOpt.CPlusPlus11))
    namedTypeToLengthModifier(QT, LM);

  // If fixing the length modifier was enough, we might be done.
  if (hasValidLengthModifier(Ctx.getTargetInfo())) {
    // If we're going to offer a fix anyway, make sure the sign matches.
    switch (CS.getKind()) {
    case ConversionSpecifier::uArg:
    case ConversionSpecifier::UArg:
      if (QT->isSignedIntegerType())
        CS.setKind(clang::analyze_format_string::ConversionSpecifier::dArg);
      break;
    case ConversionSpecifier::dArg:
    case ConversionSpecifier::DArg:
    case ConversionSpecifier::iArg:
      if (QT->isUnsignedIntegerType() && !HasPlusPrefix)
        CS.setKind(clang::analyze_format_string::ConversionSpecifier::uArg);
      break;
    default:
      // Other specifiers do not have signed/unsigned variants.
      break;
    }

    const analyze_printf::ArgType &ATR = getArgType(Ctx, IsObjCLiteral);
    if (ATR.isValid() && ATR.matchesType(Ctx, QT))
      return true;
  }

  // Set conversion specifier and disable any flags which do not apply to it.
  // Let typedefs to char fall through to int, as %c is silly for uint8_t.
  if (!isa<TypedefType>(QT) && QT->isCharType()) {
    CS.setKind(ConversionSpecifier::cArg);
    LM.setKind(LengthModifier::None);
    Precision.setHowSpecified(OptionalAmount::NotSpecified);
    HasAlternativeForm = 0;
    HasLeadingZeroes = 0;
    HasPlusPrefix = 0;
  }
  // Test for Floating type first as LongDouble can pass isUnsignedIntegerType
  else if (QT->isRealFloatingType()) {
    CS.setKind(ConversionSpecifier::fArg);
  }
  else if (QT->isSignedIntegerType()) {
    CS.setKind(ConversionSpecifier::dArg);
    HasAlternativeForm = 0;
  }
  else if (QT->isUnsignedIntegerType()) {
    CS.setKind(ConversionSpecifier::uArg);
    HasAlternativeForm = 0;
    HasPlusPrefix = 0;
  } else {
    llvm_unreachable("Unexpected type");
  }

  return true;
}

void PrintfSpecifier::toString(raw_ostream &os) const {
  // Whilst some features have no defined order, we are using the order
  // appearing in the C99 standard (ISO/IEC 9899:1999 (E) 7.19.6.1)
  os << "%";

  // Positional args
  if (usesPositionalArg()) {
    os << getPositionalArgIndex() << "$";
  }

  // Conversion flags
  if (IsLeftJustified)    os << "-";
  if (HasPlusPrefix)      os << "+";
  if (HasSpacePrefix)     os << " ";
  if (HasAlternativeForm) os << "#";
  if (HasLeadingZeroes)   os << "0";

  // Minimum field width
  FieldWidth.toString(os);
  // Precision
  Precision.toString(os);
  // Length modifier
  os << LM.toString();
  // Conversion specifier
  os << CS.toString();
}

bool PrintfSpecifier::hasValidPlusPrefix() const {
  if (!HasPlusPrefix)
    return true;

  // The plus prefix only makes sense for signed conversions
  switch (CS.getKind()) {
  case ConversionSpecifier::dArg:
  case ConversionSpecifier::DArg:
  case ConversionSpecifier::iArg:
  case ConversionSpecifier::fArg:
  case ConversionSpecifier::FArg:
  case ConversionSpecifier::eArg:
  case ConversionSpecifier::EArg:
  case ConversionSpecifier::gArg:
  case ConversionSpecifier::GArg:
  case ConversionSpecifier::aArg:
  case ConversionSpecifier::AArg:
  case ConversionSpecifier::FreeBSDrArg:
  case ConversionSpecifier::FreeBSDyArg:
    return true;

  default:
    return false;
  }
}

bool PrintfSpecifier::hasValidAlternativeForm() const {
  if (!HasAlternativeForm)
    return true;

  // Alternate form flag only valid with the oxXaAeEfFgG conversions
  switch (CS.getKind()) {
  case ConversionSpecifier::oArg:
  case ConversionSpecifier::OArg:
  case ConversionSpecifier::xArg:
  case ConversionSpecifier::XArg:
  case ConversionSpecifier::aArg:
  case ConversionSpecifier::AArg:
  case ConversionSpecifier::eArg:
  case ConversionSpecifier::EArg:
  case ConversionSpecifier::fArg:
  case ConversionSpecifier::FArg:
  case ConversionSpecifier::gArg:
  case ConversionSpecifier::GArg:
  case ConversionSpecifier::FreeBSDrArg:
  case ConversionSpecifier::FreeBSDyArg:
    return true;

  default:
    return false;
  }
}

bool PrintfSpecifier::hasValidLeadingZeros() const {
  if (!HasLeadingZeroes)
    return true;

  // Leading zeroes flag only valid with the diouxXaAeEfFgG conversions
  switch (CS.getKind()) {
  case ConversionSpecifier::dArg:
  case ConversionSpecifier::DArg:
  case ConversionSpecifier::iArg:
  case ConversionSpecifier::oArg:
  case ConversionSpecifier::OArg:
  case ConversionSpecifier::uArg:
  case ConversionSpecifier::UArg:
  case ConversionSpecifier::xArg:
  case ConversionSpecifier::XArg:
  case ConversionSpecifier::aArg:
  case ConversionSpecifier::AArg:
  case ConversionSpecifier::eArg:
  case ConversionSpecifier::EArg:
  case ConversionSpecifier::fArg:
  case ConversionSpecifier::FArg:
  case ConversionSpecifier::gArg:
  case ConversionSpecifier::GArg:
  case ConversionSpecifier::FreeBSDrArg:
  case ConversionSpecifier::FreeBSDyArg:
    return true;

  default:
    return false;
  }
}

bool PrintfSpecifier::hasValidSpacePrefix() const {
  if (!HasSpacePrefix)
    return true;

  // The space prefix only makes sense for signed conversions
  switch (CS.getKind()) {
  case ConversionSpecifier::dArg:
  case ConversionSpecifier::DArg:
  case ConversionSpecifier::iArg:
  case ConversionSpecifier::fArg:
  case ConversionSpecifier::FArg:
  case ConversionSpecifier::eArg:
  case ConversionSpecifier::EArg:
  case ConversionSpecifier::gArg:
  case ConversionSpecifier::GArg:
  case ConversionSpecifier::aArg:
  case ConversionSpecifier::AArg:
  case ConversionSpecifier::FreeBSDrArg:
  case ConversionSpecifier::FreeBSDyArg:
    return true;

  default:
    return false;
  }
}

bool PrintfSpecifier::hasValidLeftJustified() const {
  if (!IsLeftJustified)
    return true;

  // The left justified flag is valid for all conversions except n
  switch (CS.getKind()) {
  case ConversionSpecifier::nArg:
    return false;

  default:
    return true;
  }
}

bool PrintfSpecifier::hasValidThousandsGroupingPrefix() const {
  if (!HasThousandsGrouping)
    return true;

  switch (CS.getKind()) {
    case ConversionSpecifier::dArg:
    case ConversionSpecifier::DArg:
    case ConversionSpecifier::iArg:
    case ConversionSpecifier::uArg:
    case ConversionSpecifier::UArg:
    case ConversionSpecifier::fArg:
    case ConversionSpecifier::FArg:
    case ConversionSpecifier::gArg:
    case ConversionSpecifier::GArg:
      return true;
    default:
      return false;
  }
}

bool PrintfSpecifier::hasValidPrecision() const {
  if (Precision.getHowSpecified() == OptionalAmount::NotSpecified)
    return true;

  // Precision is only valid with the diouxXaAeEfFgGsP conversions
  switch (CS.getKind()) {
  case ConversionSpecifier::dArg:
  case ConversionSpecifier::DArg:
  case ConversionSpecifier::iArg:
  case ConversionSpecifier::oArg:
  case ConversionSpecifier::OArg:
  case ConversionSpecifier::uArg:
  case ConversionSpecifier::UArg:
  case ConversionSpecifier::xArg:
  case ConversionSpecifier::XArg:
  case ConversionSpecifier::aArg:
  case ConversionSpecifier::AArg:
  case ConversionSpecifier::eArg:
  case ConversionSpecifier::EArg:
  case ConversionSpecifier::fArg:
  case ConversionSpecifier::FArg:
  case ConversionSpecifier::gArg:
  case ConversionSpecifier::GArg:
  case ConversionSpecifier::sArg:
  case ConversionSpecifier::FreeBSDrArg:
  case ConversionSpecifier::FreeBSDyArg:
  case ConversionSpecifier::PArg:
    return true;

  default:
    return false;
  }
}
bool PrintfSpecifier::hasValidFieldWidth() const {
  if (FieldWidth.getHowSpecified() == OptionalAmount::NotSpecified)
      return true;

  // The field width is valid for all conversions except n
  switch (CS.getKind()) {
  case ConversionSpecifier::nArg:
    return false;

  default:
    return true;
  }
}