1// FormatString.cpp - Common stuff for handling printf/scanf formats -*- C++ -*-
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Shared details for processing format strings of printf and scanf
10// (and friends).
11//
12//===----------------------------------------------------------------------===//
13
14#include "FormatStringParsing.h"
15#include "clang/Basic/LangOptions.h"
16#include "clang/Basic/TargetInfo.h"
17#include "llvm/Support/ConvertUTF.h"
18#include <optional>
19
20using clang::analyze_format_string::ArgType;
21using clang::analyze_format_string::FormatStringHandler;
22using clang::analyze_format_string::FormatSpecifier;
23using clang::analyze_format_string::LengthModifier;
24using clang::analyze_format_string::OptionalAmount;
25using clang::analyze_format_string::ConversionSpecifier;
26using namespace clang;
27
28// Key function to FormatStringHandler.
29FormatStringHandler::~FormatStringHandler() {}
30
31//===----------------------------------------------------------------------===//
32// Functions for parsing format strings components in both printf and
33// scanf format strings.
34//===----------------------------------------------------------------------===//
35
36OptionalAmount
37clang::analyze_format_string::ParseAmount(const char *&Beg, const char *E) {
38 const char *I = Beg;
39 UpdateOnReturn <const char*> UpdateBeg(Beg, I);
40
41 unsigned accumulator = 0;
42 bool hasDigits = false;
43
44 for ( ; I != E; ++I) {
45 char c = *I;
46 if (c >= '0' && c <= '9') {
47 hasDigits = true;
48 accumulator = (accumulator * 10) + (c - '0');
49 continue;
50 }
51
52 if (hasDigits)
53 return OptionalAmount(OptionalAmount::Constant, accumulator, Beg, I - Beg,
54 false);
55
56 break;
57 }
58
59 return OptionalAmount();
60}
61
62OptionalAmount
63clang::analyze_format_string::ParseNonPositionAmount(const char *&Beg,
64 const char *E,
65 unsigned &argIndex) {
66 if (*Beg == '*') {
67 ++Beg;
68 return OptionalAmount(OptionalAmount::Arg, argIndex++, Beg, 0, false);
69 }
70
71 return ParseAmount(Beg, E);
72}
73
74OptionalAmount
75clang::analyze_format_string::ParsePositionAmount(FormatStringHandler &H,
76 const char *Start,
77 const char *&Beg,
78 const char *E,
79 PositionContext p) {
80 if (*Beg == '*') {
81 const char *I = Beg + 1;
82 const OptionalAmount &Amt = ParseAmount(Beg&: I, E);
83
84 if (Amt.getHowSpecified() == OptionalAmount::NotSpecified) {
85 H.HandleInvalidPosition(startPos: Beg, posLen: I - Beg, p);
86 return OptionalAmount(false);
87 }
88
89 if (I == E) {
90 // No more characters left?
91 H.HandleIncompleteSpecifier(startSpecifier: Start, specifierLen: E - Start);
92 return OptionalAmount(false);
93 }
94
95 assert(Amt.getHowSpecified() == OptionalAmount::Constant);
96
97 if (*I == '$') {
98 // Handle positional arguments
99
100 // Special case: '*0$', since this is an easy mistake.
101 if (Amt.getConstantAmount() == 0) {
102 H.HandleZeroPosition(startPos: Beg, posLen: I - Beg + 1);
103 return OptionalAmount(false);
104 }
105
106 const char *Tmp = Beg;
107 Beg = ++I;
108
109 return OptionalAmount(OptionalAmount::Arg, Amt.getConstantAmount() - 1,
110 Tmp, 0, true);
111 }
112
113 H.HandleInvalidPosition(startPos: Beg, posLen: I - Beg, p);
114 return OptionalAmount(false);
115 }
116
117 return ParseAmount(Beg, E);
118}
119
120
121bool
122clang::analyze_format_string::ParseFieldWidth(FormatStringHandler &H,
123 FormatSpecifier &CS,
124 const char *Start,
125 const char *&Beg, const char *E,
126 unsigned *argIndex) {
127 // FIXME: Support negative field widths.
128 if (argIndex) {
129 CS.setFieldWidth(ParseNonPositionAmount(Beg, E, argIndex&: *argIndex));
130 }
131 else {
132 const OptionalAmount Amt =
133 ParsePositionAmount(H, Start, Beg, E,
134 p: analyze_format_string::FieldWidthPos);
135
136 if (Amt.isInvalid())
137 return true;
138 CS.setFieldWidth(Amt);
139 }
140 return false;
141}
142
143bool
144clang::analyze_format_string::ParseArgPosition(FormatStringHandler &H,
145 FormatSpecifier &FS,
146 const char *Start,
147 const char *&Beg,
148 const char *E) {
149 const char *I = Beg;
150
151 const OptionalAmount &Amt = ParseAmount(Beg&: I, E);
152
153 if (I == E) {
154 // No more characters left?
155 H.HandleIncompleteSpecifier(startSpecifier: Start, specifierLen: E - Start);
156 return true;
157 }
158
159 if (Amt.getHowSpecified() == OptionalAmount::Constant && *(I++) == '$') {
160 // Warn that positional arguments are non-standard.
161 H.HandlePosition(startPos: Start, posLen: I - Start);
162
163 // Special case: '%0$', since this is an easy mistake.
164 if (Amt.getConstantAmount() == 0) {
165 H.HandleZeroPosition(startPos: Start, posLen: I - Start);
166 return true;
167 }
168
169 FS.setArgIndex(Amt.getConstantAmount() - 1);
170 FS.setUsesPositionalArg();
171 // Update the caller's pointer if we decided to consume
172 // these characters.
173 Beg = I;
174 return false;
175 }
176
177 return false;
178}
179
180bool
181clang::analyze_format_string::ParseVectorModifier(FormatStringHandler &H,
182 FormatSpecifier &FS,
183 const char *&I,
184 const char *E,
185 const LangOptions &LO) {
186 if (!LO.OpenCL)
187 return false;
188
189 const char *Start = I;
190 if (*I == 'v') {
191 ++I;
192
193 if (I == E) {
194 H.HandleIncompleteSpecifier(startSpecifier: Start, specifierLen: E - Start);
195 return true;
196 }
197
198 OptionalAmount NumElts = ParseAmount(Beg&: I, E);
199 if (NumElts.getHowSpecified() != OptionalAmount::Constant) {
200 H.HandleIncompleteSpecifier(startSpecifier: Start, specifierLen: E - Start);
201 return true;
202 }
203
204 FS.setVectorNumElts(NumElts);
205 }
206
207 return false;
208}
209
210bool
211clang::analyze_format_string::ParseLengthModifier(FormatSpecifier &FS,
212 const char *&I,
213 const char *E,
214 const LangOptions &LO,
215 bool IsScanf) {
216 LengthModifier::Kind lmKind = LengthModifier::None;
217 const char *lmPosition = I;
218 switch (*I) {
219 default:
220 return false;
221 case 'h':
222 ++I;
223 if (I != E && *I == 'h') {
224 ++I;
225 lmKind = LengthModifier::AsChar;
226 } else if (I != E && *I == 'l' && LO.OpenCL) {
227 ++I;
228 lmKind = LengthModifier::AsShortLong;
229 } else {
230 lmKind = LengthModifier::AsShort;
231 }
232 break;
233 case 'l':
234 ++I;
235 if (I != E && *I == 'l') {
236 ++I;
237 lmKind = LengthModifier::AsLongLong;
238 } else {
239 lmKind = LengthModifier::AsLong;
240 }
241 break;
242 case 'j': lmKind = LengthModifier::AsIntMax; ++I; break;
243 case 'z': lmKind = LengthModifier::AsSizeT; ++I; break;
244 case 't': lmKind = LengthModifier::AsPtrDiff; ++I; break;
245 case 'L': lmKind = LengthModifier::AsLongDouble; ++I; break;
246 case 'q': lmKind = LengthModifier::AsQuad; ++I; break;
247 case 'a':
248 if (IsScanf && !LO.C99 && !LO.CPlusPlus11) {
249 // For scanf in C90, look at the next character to see if this should
250 // be parsed as the GNU extension 'a' length modifier. If not, this
251 // will be parsed as a conversion specifier.
252 ++I;
253 if (I != E && (*I == 's' || *I == 'S' || *I == '[')) {
254 lmKind = LengthModifier::AsAllocate;
255 break;
256 }
257 --I;
258 }
259 return false;
260 case 'm':
261 if (IsScanf) {
262 lmKind = LengthModifier::AsMAllocate;
263 ++I;
264 break;
265 }
266 return false;
267 // printf: AsInt64, AsInt32, AsInt3264
268 // scanf: AsInt64
269 case 'I':
270 if (I + 1 != E && I + 2 != E) {
271 if (I[1] == '6' && I[2] == '4') {
272 I += 3;
273 lmKind = LengthModifier::AsInt64;
274 break;
275 }
276 if (IsScanf)
277 return false;
278
279 if (I[1] == '3' && I[2] == '2') {
280 I += 3;
281 lmKind = LengthModifier::AsInt32;
282 break;
283 }
284 }
285 ++I;
286 lmKind = LengthModifier::AsInt3264;
287 break;
288 case 'w':
289 lmKind = LengthModifier::AsWide; ++I; break;
290 }
291 LengthModifier lm(lmPosition, lmKind);
292 FS.setLengthModifier(lm);
293 return true;
294}
295
296bool clang::analyze_format_string::ParseUTF8InvalidSpecifier(
297 const char *SpecifierBegin, const char *FmtStrEnd, unsigned &Len) {
298 if (SpecifierBegin + 1 >= FmtStrEnd)
299 return false;
300
301 const llvm::UTF8 *SB =
302 reinterpret_cast<const llvm::UTF8 *>(SpecifierBegin + 1);
303 const llvm::UTF8 *SE = reinterpret_cast<const llvm::UTF8 *>(FmtStrEnd);
304 const char FirstByte = *SB;
305
306 // If the invalid specifier is a multibyte UTF-8 string, return the
307 // total length accordingly so that the conversion specifier can be
308 // properly updated to reflect a complete UTF-8 specifier.
309 unsigned NumBytes = llvm::getNumBytesForUTF8(firstByte: FirstByte);
310 if (NumBytes == 1)
311 return false;
312 if (SB + NumBytes > SE)
313 return false;
314
315 Len = NumBytes + 1;
316 return true;
317}
318
319//===----------------------------------------------------------------------===//
320// Methods on ArgType.
321//===----------------------------------------------------------------------===//
322
323clang::analyze_format_string::ArgType::MatchKind
324ArgType::matchesType(ASTContext &C, QualType argTy) const {
325 // When using the format attribute in C++, you can receive a function or an
326 // array that will necessarily decay to a pointer when passed to the final
327 // format consumer. Apply decay before type comparison.
328 if (argTy->canDecayToPointerType())
329 argTy = C.getDecayedType(T: argTy);
330
331 if (Ptr) {
332 // It has to be a pointer.
333 const PointerType *PT = argTy->getAs<PointerType>();
334 if (!PT)
335 return NoMatch;
336
337 // We cannot write through a const qualified pointer.
338 if (PT->getPointeeType().isConstQualified())
339 return NoMatch;
340
341 argTy = PT->getPointeeType();
342 }
343
344 switch (K) {
345 case InvalidTy:
346 llvm_unreachable("ArgType must be valid");
347
348 case UnknownTy:
349 return Match;
350
351 case AnyCharTy: {
352 if (const auto *ETy = argTy->getAs<EnumType>()) {
353 // If the enum is incomplete we know nothing about the underlying type.
354 // Assume that it's 'int'. Do not use the underlying type for a scoped
355 // enumeration.
356 if (!ETy->getDecl()->isComplete())
357 return NoMatch;
358 if (ETy->isUnscopedEnumerationType())
359 argTy = ETy->getDecl()->getIntegerType();
360 }
361
362 if (const auto *BT = argTy->getAs<BuiltinType>()) {
363 // The types are perfectly matched?
364 switch (BT->getKind()) {
365 default:
366 break;
367 case BuiltinType::Char_S:
368 case BuiltinType::SChar:
369 case BuiltinType::UChar:
370 case BuiltinType::Char_U:
371 return Match;
372 case BuiltinType::Bool:
373 if (!Ptr)
374 return Match;
375 break;
376 }
377 // "Partially matched" because of promotions?
378 if (!Ptr) {
379 switch (BT->getKind()) {
380 default:
381 break;
382 case BuiltinType::Int:
383 case BuiltinType::UInt:
384 return MatchPromotion;
385 case BuiltinType::Short:
386 case BuiltinType::UShort:
387 case BuiltinType::WChar_S:
388 case BuiltinType::WChar_U:
389 return NoMatchPromotionTypeConfusion;
390 }
391 }
392 }
393 return NoMatch;
394 }
395
396 case SpecificTy: {
397 if (const EnumType *ETy = argTy->getAs<EnumType>()) {
398 // If the enum is incomplete we know nothing about the underlying type.
399 // Assume that it's 'int'. Do not use the underlying type for a scoped
400 // enumeration as that needs an exact match.
401 if (!ETy->getDecl()->isComplete())
402 argTy = C.IntTy;
403 else if (ETy->isUnscopedEnumerationType())
404 argTy = ETy->getDecl()->getIntegerType();
405 }
406
407 if (argTy->isSaturatedFixedPointType())
408 argTy = C.getCorrespondingUnsaturatedType(Ty: argTy);
409
410 argTy = C.getCanonicalType(T: argTy).getUnqualifiedType();
411
412 if (T == argTy)
413 return Match;
414 if (const auto *BT = argTy->getAs<BuiltinType>()) {
415 // Check if the only difference between them is signed vs unsigned
416 // if true, return match signedness.
417 switch (BT->getKind()) {
418 default:
419 break;
420 case BuiltinType::Bool:
421 if (Ptr && (T == C.UnsignedCharTy || T == C.SignedCharTy))
422 return NoMatch;
423 [[fallthrough]];
424 case BuiltinType::Char_S:
425 case BuiltinType::SChar:
426 if (T == C.UnsignedShortTy || T == C.ShortTy)
427 return NoMatchTypeConfusion;
428 if (T == C.UnsignedCharTy)
429 return NoMatchSignedness;
430 if (T == C.SignedCharTy)
431 return Match;
432 break;
433 case BuiltinType::Char_U:
434 case BuiltinType::UChar:
435 if (T == C.UnsignedShortTy || T == C.ShortTy)
436 return NoMatchTypeConfusion;
437 if (T == C.UnsignedCharTy)
438 return Match;
439 if (T == C.SignedCharTy)
440 return NoMatchSignedness;
441 break;
442 case BuiltinType::Short:
443 if (T == C.UnsignedShortTy)
444 return NoMatchSignedness;
445 break;
446 case BuiltinType::UShort:
447 if (T == C.ShortTy)
448 return NoMatchSignedness;
449 break;
450 case BuiltinType::Int:
451 if (T == C.UnsignedIntTy)
452 return NoMatchSignedness;
453 break;
454 case BuiltinType::UInt:
455 if (T == C.IntTy)
456 return NoMatchSignedness;
457 break;
458 case BuiltinType::Long:
459 if (T == C.UnsignedLongTy)
460 return NoMatchSignedness;
461 break;
462 case BuiltinType::ULong:
463 if (T == C.LongTy)
464 return NoMatchSignedness;
465 break;
466 case BuiltinType::LongLong:
467 if (T == C.UnsignedLongLongTy)
468 return NoMatchSignedness;
469 break;
470 case BuiltinType::ULongLong:
471 if (T == C.LongLongTy)
472 return NoMatchSignedness;
473 break;
474 }
475 // "Partially matched" because of promotions?
476 if (!Ptr) {
477 switch (BT->getKind()) {
478 default:
479 break;
480 case BuiltinType::Bool:
481 if (T == C.IntTy || T == C.UnsignedIntTy)
482 return MatchPromotion;
483 break;
484 case BuiltinType::Int:
485 case BuiltinType::UInt:
486 if (T == C.SignedCharTy || T == C.UnsignedCharTy ||
487 T == C.ShortTy || T == C.UnsignedShortTy || T == C.WCharTy ||
488 T == C.WideCharTy)
489 return MatchPromotion;
490 break;
491 case BuiltinType::Char_U:
492 if (T == C.UnsignedIntTy)
493 return MatchPromotion;
494 if (T == C.UnsignedShortTy)
495 return NoMatchPromotionTypeConfusion;
496 break;
497 case BuiltinType::Char_S:
498 if (T == C.IntTy)
499 return MatchPromotion;
500 if (T == C.ShortTy)
501 return NoMatchPromotionTypeConfusion;
502 break;
503 case BuiltinType::Half:
504 case BuiltinType::Float:
505 if (T == C.DoubleTy)
506 return MatchPromotion;
507 break;
508 case BuiltinType::Short:
509 case BuiltinType::UShort:
510 if (T == C.SignedCharTy || T == C.UnsignedCharTy)
511 return NoMatchPromotionTypeConfusion;
512 break;
513 case BuiltinType::WChar_U:
514 case BuiltinType::WChar_S:
515 if (T != C.WCharTy && T != C.WideCharTy)
516 return NoMatchPromotionTypeConfusion;
517 }
518 }
519 }
520 return NoMatch;
521 }
522
523 case CStrTy: {
524 const PointerType *PT = argTy->getAs<PointerType>();
525 if (!PT)
526 return NoMatch;
527 QualType pointeeTy = PT->getPointeeType();
528 if (const BuiltinType *BT = pointeeTy->getAs<BuiltinType>())
529 switch (BT->getKind()) {
530 case BuiltinType::Char_U:
531 case BuiltinType::UChar:
532 case BuiltinType::Char_S:
533 case BuiltinType::SChar:
534 return Match;
535 default:
536 break;
537 }
538
539 return NoMatch;
540 }
541
542 case WCStrTy: {
543 const PointerType *PT = argTy->getAs<PointerType>();
544 if (!PT)
545 return NoMatch;
546 QualType pointeeTy =
547 C.getCanonicalType(T: PT->getPointeeType()).getUnqualifiedType();
548 return pointeeTy == C.getWideCharType() ? Match : NoMatch;
549 }
550
551 case WIntTy: {
552 QualType WInt = C.getCanonicalType(T: C.getWIntType()).getUnqualifiedType();
553
554 if (C.getCanonicalType(T: argTy).getUnqualifiedType() == WInt)
555 return Match;
556
557 QualType PromoArg = C.isPromotableIntegerType(T: argTy)
558 ? C.getPromotedIntegerType(PromotableType: argTy)
559 : argTy;
560 PromoArg = C.getCanonicalType(T: PromoArg).getUnqualifiedType();
561
562 // If the promoted argument is the corresponding signed type of the
563 // wint_t type, then it should match.
564 if (PromoArg->hasSignedIntegerRepresentation() &&
565 C.getCorrespondingUnsignedType(T: PromoArg) == WInt)
566 return Match;
567
568 return WInt == PromoArg ? Match : NoMatch;
569 }
570
571 case CPointerTy:
572 if (argTy->isVoidPointerType()) {
573 return Match;
574 } if (argTy->isPointerType() || argTy->isObjCObjectPointerType() ||
575 argTy->isBlockPointerType() || argTy->isNullPtrType()) {
576 return NoMatchPedantic;
577 } else {
578 return NoMatch;
579 }
580
581 case ObjCPointerTy: {
582 if (argTy->getAs<ObjCObjectPointerType>() ||
583 argTy->getAs<BlockPointerType>())
584 return Match;
585
586 // Handle implicit toll-free bridging.
587 if (const PointerType *PT = argTy->getAs<PointerType>()) {
588 // Things such as CFTypeRef are really just opaque pointers
589 // to C structs representing CF types that can often be bridged
590 // to Objective-C objects. Since the compiler doesn't know which
591 // structs can be toll-free bridged, we just accept them all.
592 QualType pointee = PT->getPointeeType();
593 if (pointee->getAsStructureType() || pointee->isVoidType())
594 return Match;
595 }
596 return NoMatch;
597 }
598 }
599
600 llvm_unreachable("Invalid ArgType Kind!");
601}
602
603ArgType ArgType::makeVectorType(ASTContext &C, unsigned NumElts) const {
604 // Check for valid vector element types.
605 if (T.isNull())
606 return ArgType::Invalid();
607
608 QualType Vec = C.getExtVectorType(T, NumElts);
609 return ArgType(Vec, Name);
610}
611
612QualType ArgType::getRepresentativeType(ASTContext &C) const {
613 QualType Res;
614 switch (K) {
615 case InvalidTy:
616 llvm_unreachable("No representative type for Invalid ArgType");
617 case UnknownTy:
618 llvm_unreachable("No representative type for Unknown ArgType");
619 case AnyCharTy:
620 Res = C.CharTy;
621 break;
622 case SpecificTy:
623 Res = T;
624 break;
625 case CStrTy:
626 Res = C.getPointerType(C.CharTy);
627 break;
628 case WCStrTy:
629 Res = C.getPointerType(T: C.getWideCharType());
630 break;
631 case ObjCPointerTy:
632 Res = C.ObjCBuiltinIdTy;
633 break;
634 case CPointerTy:
635 Res = C.VoidPtrTy;
636 break;
637 case WIntTy: {
638 Res = C.getWIntType();
639 break;
640 }
641 }
642
643 if (Ptr)
644 Res = C.getPointerType(T: Res);
645 return Res;
646}
647
648std::string ArgType::getRepresentativeTypeName(ASTContext &C) const {
649 std::string S = getRepresentativeType(C).getAsString(Policy: C.getPrintingPolicy());
650
651 std::string Alias;
652 if (Name) {
653 // Use a specific name for this type, e.g. "size_t".
654 Alias = Name;
655 if (Ptr) {
656 // If ArgType is actually a pointer to T, append an asterisk.
657 Alias += (Alias[Alias.size()-1] == '*') ? "*" : " *";
658 }
659 // If Alias is the same as the underlying type, e.g. wchar_t, then drop it.
660 if (S == Alias)
661 Alias.clear();
662 }
663
664 if (!Alias.empty())
665 return std::string("'") + Alias + "' (aka '" + S + "')";
666 return std::string("'") + S + "'";
667}
668
669
670//===----------------------------------------------------------------------===//
671// Methods on OptionalAmount.
672//===----------------------------------------------------------------------===//
673
674ArgType
675analyze_format_string::OptionalAmount::getArgType(ASTContext &Ctx) const {
676 return Ctx.IntTy;
677}
678
679//===----------------------------------------------------------------------===//
680// Methods on LengthModifier.
681//===----------------------------------------------------------------------===//
682
683const char *
684analyze_format_string::LengthModifier::toString() const {
685 switch (kind) {
686 case AsChar:
687 return "hh";
688 case AsShort:
689 return "h";
690 case AsShortLong:
691 return "hl";
692 case AsLong: // or AsWideChar
693 return "l";
694 case AsLongLong:
695 return "ll";
696 case AsQuad:
697 return "q";
698 case AsIntMax:
699 return "j";
700 case AsSizeT:
701 return "z";
702 case AsPtrDiff:
703 return "t";
704 case AsInt32:
705 return "I32";
706 case AsInt3264:
707 return "I";
708 case AsInt64:
709 return "I64";
710 case AsLongDouble:
711 return "L";
712 case AsAllocate:
713 return "a";
714 case AsMAllocate:
715 return "m";
716 case AsWide:
717 return "w";
718 case None:
719 return "";
720 }
721 return nullptr;
722}
723
724//===----------------------------------------------------------------------===//
725// Methods on ConversionSpecifier.
726//===----------------------------------------------------------------------===//
727
728const char *ConversionSpecifier::toString() const {
729 switch (kind) {
730 case bArg: return "b";
731 case BArg: return "B";
732 case dArg: return "d";
733 case DArg: return "D";
734 case iArg: return "i";
735 case oArg: return "o";
736 case OArg: return "O";
737 case uArg: return "u";
738 case UArg: return "U";
739 case xArg: return "x";
740 case XArg: return "X";
741 case fArg: return "f";
742 case FArg: return "F";
743 case eArg: return "e";
744 case EArg: return "E";
745 case gArg: return "g";
746 case GArg: return "G";
747 case aArg: return "a";
748 case AArg: return "A";
749 case cArg: return "c";
750 case sArg: return "s";
751 case pArg: return "p";
752 case PArg:
753 return "P";
754 case nArg: return "n";
755 case PercentArg: return "%";
756 case ScanListArg: return "[";
757 case InvalidSpecifier: return nullptr;
758
759 // POSIX unicode extensions.
760 case CArg: return "C";
761 case SArg: return "S";
762
763 // Objective-C specific specifiers.
764 case ObjCObjArg: return "@";
765
766 // FreeBSD kernel specific specifiers.
767 case FreeBSDbArg: return "b";
768 case FreeBSDDArg: return "D";
769 case FreeBSDrArg: return "r";
770 case FreeBSDyArg: return "y";
771
772 // GlibC specific specifiers.
773 case PrintErrno: return "m";
774
775 // MS specific specifiers.
776 case ZArg: return "Z";
777
778 // ISO/IEC TR 18037 (fixed-point) specific specifiers.
779 case rArg:
780 return "r";
781 case RArg:
782 return "R";
783 case kArg:
784 return "k";
785 case KArg:
786 return "K";
787 }
788 return nullptr;
789}
790
791std::optional<ConversionSpecifier>
792ConversionSpecifier::getStandardSpecifier() const {
793 ConversionSpecifier::Kind NewKind;
794
795 switch (getKind()) {
796 default:
797 return std::nullopt;
798 case DArg:
799 NewKind = dArg;
800 break;
801 case UArg:
802 NewKind = uArg;
803 break;
804 case OArg:
805 NewKind = oArg;
806 break;
807 }
808
809 ConversionSpecifier FixedCS(*this);
810 FixedCS.setKind(NewKind);
811 return FixedCS;
812}
813
814//===----------------------------------------------------------------------===//
815// Methods on OptionalAmount.
816//===----------------------------------------------------------------------===//
817
818void OptionalAmount::toString(raw_ostream &os) const {
819 switch (hs) {
820 case Invalid:
821 case NotSpecified:
822 return;
823 case Arg:
824 if (UsesDotPrefix)
825 os << ".";
826 if (usesPositionalArg())
827 os << "*" << getPositionalArgIndex() << "$";
828 else
829 os << "*";
830 break;
831 case Constant:
832 if (UsesDotPrefix)
833 os << ".";
834 os << amt;
835 break;
836 }
837}
838
839bool FormatSpecifier::hasValidLengthModifier(const TargetInfo &Target,
840 const LangOptions &LO) const {
841 switch (LM.getKind()) {
842 case LengthModifier::None:
843 return true;
844
845 // Handle most integer flags
846 case LengthModifier::AsShort:
847 // Length modifier only applies to FP vectors.
848 if (LO.OpenCL && CS.isDoubleArg())
849 return !VectorNumElts.isInvalid();
850
851 if (CS.isFixedPointArg())
852 return true;
853
854 if (Target.getTriple().isOSMSVCRT()) {
855 switch (CS.getKind()) {
856 case ConversionSpecifier::cArg:
857 case ConversionSpecifier::CArg:
858 case ConversionSpecifier::sArg:
859 case ConversionSpecifier::SArg:
860 case ConversionSpecifier::ZArg:
861 return true;
862 default:
863 break;
864 }
865 }
866 [[fallthrough]];
867 case LengthModifier::AsChar:
868 case LengthModifier::AsLongLong:
869 case LengthModifier::AsQuad:
870 case LengthModifier::AsIntMax:
871 case LengthModifier::AsSizeT:
872 case LengthModifier::AsPtrDiff:
873 switch (CS.getKind()) {
874 case ConversionSpecifier::bArg:
875 case ConversionSpecifier::BArg:
876 case ConversionSpecifier::dArg:
877 case ConversionSpecifier::DArg:
878 case ConversionSpecifier::iArg:
879 case ConversionSpecifier::oArg:
880 case ConversionSpecifier::OArg:
881 case ConversionSpecifier::uArg:
882 case ConversionSpecifier::UArg:
883 case ConversionSpecifier::xArg:
884 case ConversionSpecifier::XArg:
885 case ConversionSpecifier::nArg:
886 return true;
887 case ConversionSpecifier::FreeBSDrArg:
888 case ConversionSpecifier::FreeBSDyArg:
889 return Target.getTriple().isOSFreeBSD() || Target.getTriple().isPS();
890 default:
891 return false;
892 }
893
894 case LengthModifier::AsShortLong:
895 return LO.OpenCL && !VectorNumElts.isInvalid();
896
897 // Handle 'l' flag
898 case LengthModifier::AsLong: // or AsWideChar
899 if (CS.isDoubleArg()) {
900 // Invalid for OpenCL FP scalars.
901 if (LO.OpenCL && VectorNumElts.isInvalid())
902 return false;
903 return true;
904 }
905
906 if (CS.isFixedPointArg())
907 return true;
908
909 switch (CS.getKind()) {
910 case ConversionSpecifier::bArg:
911 case ConversionSpecifier::BArg:
912 case ConversionSpecifier::dArg:
913 case ConversionSpecifier::DArg:
914 case ConversionSpecifier::iArg:
915 case ConversionSpecifier::oArg:
916 case ConversionSpecifier::OArg:
917 case ConversionSpecifier::uArg:
918 case ConversionSpecifier::UArg:
919 case ConversionSpecifier::xArg:
920 case ConversionSpecifier::XArg:
921 case ConversionSpecifier::nArg:
922 case ConversionSpecifier::cArg:
923 case ConversionSpecifier::sArg:
924 case ConversionSpecifier::ScanListArg:
925 case ConversionSpecifier::ZArg:
926 return true;
927 case ConversionSpecifier::FreeBSDrArg:
928 case ConversionSpecifier::FreeBSDyArg:
929 return Target.getTriple().isOSFreeBSD() || Target.getTriple().isPS();
930 default:
931 return false;
932 }
933
934 case LengthModifier::AsLongDouble:
935 switch (CS.getKind()) {
936 case ConversionSpecifier::aArg:
937 case ConversionSpecifier::AArg:
938 case ConversionSpecifier::fArg:
939 case ConversionSpecifier::FArg:
940 case ConversionSpecifier::eArg:
941 case ConversionSpecifier::EArg:
942 case ConversionSpecifier::gArg:
943 case ConversionSpecifier::GArg:
944 return true;
945 // GNU libc extension.
946 case ConversionSpecifier::dArg:
947 case ConversionSpecifier::iArg:
948 case ConversionSpecifier::oArg:
949 case ConversionSpecifier::uArg:
950 case ConversionSpecifier::xArg:
951 case ConversionSpecifier::XArg:
952 return !Target.getTriple().isOSDarwin() &&
953 !Target.getTriple().isOSWindows();
954 default:
955 return false;
956 }
957
958 case LengthModifier::AsAllocate:
959 switch (CS.getKind()) {
960 case ConversionSpecifier::sArg:
961 case ConversionSpecifier::SArg:
962 case ConversionSpecifier::ScanListArg:
963 return true;
964 default:
965 return false;
966 }
967
968 case LengthModifier::AsMAllocate:
969 switch (CS.getKind()) {
970 case ConversionSpecifier::cArg:
971 case ConversionSpecifier::CArg:
972 case ConversionSpecifier::sArg:
973 case ConversionSpecifier::SArg:
974 case ConversionSpecifier::ScanListArg:
975 return true;
976 default:
977 return false;
978 }
979 case LengthModifier::AsInt32:
980 case LengthModifier::AsInt3264:
981 case LengthModifier::AsInt64:
982 switch (CS.getKind()) {
983 case ConversionSpecifier::dArg:
984 case ConversionSpecifier::iArg:
985 case ConversionSpecifier::oArg:
986 case ConversionSpecifier::uArg:
987 case ConversionSpecifier::xArg:
988 case ConversionSpecifier::XArg:
989 return Target.getTriple().isOSMSVCRT();
990 default:
991 return false;
992 }
993 case LengthModifier::AsWide:
994 switch (CS.getKind()) {
995 case ConversionSpecifier::cArg:
996 case ConversionSpecifier::CArg:
997 case ConversionSpecifier::sArg:
998 case ConversionSpecifier::SArg:
999 case ConversionSpecifier::ZArg:
1000 return Target.getTriple().isOSMSVCRT();
1001 default:
1002 return false;
1003 }
1004 }
1005 llvm_unreachable("Invalid LengthModifier Kind!");
1006}
1007
1008bool FormatSpecifier::hasStandardLengthModifier() const {
1009 switch (LM.getKind()) {
1010 case LengthModifier::None:
1011 case LengthModifier::AsChar:
1012 case LengthModifier::AsShort:
1013 case LengthModifier::AsLong:
1014 case LengthModifier::AsLongLong:
1015 case LengthModifier::AsIntMax:
1016 case LengthModifier::AsSizeT:
1017 case LengthModifier::AsPtrDiff:
1018 case LengthModifier::AsLongDouble:
1019 return true;
1020 case LengthModifier::AsAllocate:
1021 case LengthModifier::AsMAllocate:
1022 case LengthModifier::AsQuad:
1023 case LengthModifier::AsInt32:
1024 case LengthModifier::AsInt3264:
1025 case LengthModifier::AsInt64:
1026 case LengthModifier::AsWide:
1027 case LengthModifier::AsShortLong: // ???
1028 return false;
1029 }
1030 llvm_unreachable("Invalid LengthModifier Kind!");
1031}
1032
1033bool FormatSpecifier::hasStandardConversionSpecifier(
1034 const LangOptions &LangOpt) const {
1035 switch (CS.getKind()) {
1036 case ConversionSpecifier::bArg:
1037 case ConversionSpecifier::BArg:
1038 case ConversionSpecifier::cArg:
1039 case ConversionSpecifier::dArg:
1040 case ConversionSpecifier::iArg:
1041 case ConversionSpecifier::oArg:
1042 case ConversionSpecifier::uArg:
1043 case ConversionSpecifier::xArg:
1044 case ConversionSpecifier::XArg:
1045 case ConversionSpecifier::fArg:
1046 case ConversionSpecifier::FArg:
1047 case ConversionSpecifier::eArg:
1048 case ConversionSpecifier::EArg:
1049 case ConversionSpecifier::gArg:
1050 case ConversionSpecifier::GArg:
1051 case ConversionSpecifier::aArg:
1052 case ConversionSpecifier::AArg:
1053 case ConversionSpecifier::sArg:
1054 case ConversionSpecifier::pArg:
1055 case ConversionSpecifier::nArg:
1056 case ConversionSpecifier::ObjCObjArg:
1057 case ConversionSpecifier::ScanListArg:
1058 case ConversionSpecifier::PercentArg:
1059 case ConversionSpecifier::PArg:
1060 return true;
1061 case ConversionSpecifier::CArg:
1062 case ConversionSpecifier::SArg:
1063 return LangOpt.ObjC;
1064 case ConversionSpecifier::InvalidSpecifier:
1065 case ConversionSpecifier::FreeBSDbArg:
1066 case ConversionSpecifier::FreeBSDDArg:
1067 case ConversionSpecifier::FreeBSDrArg:
1068 case ConversionSpecifier::FreeBSDyArg:
1069 case ConversionSpecifier::PrintErrno:
1070 case ConversionSpecifier::DArg:
1071 case ConversionSpecifier::OArg:
1072 case ConversionSpecifier::UArg:
1073 case ConversionSpecifier::ZArg:
1074 return false;
1075 case ConversionSpecifier::rArg:
1076 case ConversionSpecifier::RArg:
1077 case ConversionSpecifier::kArg:
1078 case ConversionSpecifier::KArg:
1079 return LangOpt.FixedPoint;
1080 }
1081 llvm_unreachable("Invalid ConversionSpecifier Kind!");
1082}
1083
1084bool FormatSpecifier::hasStandardLengthConversionCombination() const {
1085 if (LM.getKind() == LengthModifier::AsLongDouble) {
1086 switch(CS.getKind()) {
1087 case ConversionSpecifier::dArg:
1088 case ConversionSpecifier::iArg:
1089 case ConversionSpecifier::oArg:
1090 case ConversionSpecifier::uArg:
1091 case ConversionSpecifier::xArg:
1092 case ConversionSpecifier::XArg:
1093 return false;
1094 default:
1095 return true;
1096 }
1097 }
1098 return true;
1099}
1100
1101std::optional<LengthModifier>
1102FormatSpecifier::getCorrectedLengthModifier() const {
1103 if (CS.isAnyIntArg() || CS.getKind() == ConversionSpecifier::nArg) {
1104 if (LM.getKind() == LengthModifier::AsLongDouble ||
1105 LM.getKind() == LengthModifier::AsQuad) {
1106 LengthModifier FixedLM(LM);
1107 FixedLM.setKind(LengthModifier::AsLongLong);
1108 return FixedLM;
1109 }
1110 }
1111
1112 return std::nullopt;
1113}
1114
1115bool FormatSpecifier::namedTypeToLengthModifier(QualType QT,
1116 LengthModifier &LM) {
1117 for (/**/; const auto *TT = QT->getAs<TypedefType>();
1118 QT = TT->getDecl()->getUnderlyingType()) {
1119 const TypedefNameDecl *Typedef = TT->getDecl();
1120 const IdentifierInfo *Identifier = Typedef->getIdentifier();
1121 if (Identifier->getName() == "size_t") {
1122 LM.setKind(LengthModifier::AsSizeT);
1123 return true;
1124 } else if (Identifier->getName() == "ssize_t") {
1125 // Not C99, but common in Unix.
1126 LM.setKind(LengthModifier::AsSizeT);
1127 return true;
1128 } else if (Identifier->getName() == "intmax_t") {
1129 LM.setKind(LengthModifier::AsIntMax);
1130 return true;
1131 } else if (Identifier->getName() == "uintmax_t") {
1132 LM.setKind(LengthModifier::AsIntMax);
1133 return true;
1134 } else if (Identifier->getName() == "ptrdiff_t") {
1135 LM.setKind(LengthModifier::AsPtrDiff);
1136 return true;
1137 }
1138 }
1139 return false;
1140}
1141

source code of clang/lib/AST/FormatString.cpp