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
20 using clang::analyze_format_string::ArgType;
21 using clang::analyze_format_string::FormatStringHandler;
22 using clang::analyze_format_string::FormatSpecifier;
23 using clang::analyze_format_string::LengthModifier;
24 using clang::analyze_format_string::OptionalAmount;
25 using clang::analyze_format_string::ConversionSpecifier;
26 using namespace clang;
27
28 // Key function to FormatStringHandler.
~FormatStringHandler()29 FormatStringHandler::~FormatStringHandler() {}
30
31 //===----------------------------------------------------------------------===//
32 // Functions for parsing format strings components in both printf and
33 // scanf format strings.
34 //===----------------------------------------------------------------------===//
35
36 OptionalAmount
ParseAmount(const char * & Beg,const char * E)37 clang::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
62 OptionalAmount
ParseNonPositionAmount(const char * & Beg,const char * E,unsigned & argIndex)63 clang::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
74 OptionalAmount
ParsePositionAmount(FormatStringHandler & H,const char * Start,const char * & Beg,const char * E,PositionContext p)75 clang::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(I, E);
83
84 if (Amt.getHowSpecified() == OptionalAmount::NotSpecified) {
85 H.HandleInvalidPosition(Beg, I - Beg, p);
86 return OptionalAmount(false);
87 }
88
89 if (I == E) {
90 // No more characters left?
91 H.HandleIncompleteSpecifier(Start, 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(Beg, 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(Beg, I - Beg, p);
114 return OptionalAmount(false);
115 }
116
117 return ParseAmount(Beg, E);
118 }
119
120
121 bool
ParseFieldWidth(FormatStringHandler & H,FormatSpecifier & CS,const char * Start,const char * & Beg,const char * E,unsigned * argIndex)122 clang::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));
130 }
131 else {
132 const OptionalAmount Amt =
133 ParsePositionAmount(H, Start, Beg, E,
134 analyze_format_string::FieldWidthPos);
135
136 if (Amt.isInvalid())
137 return true;
138 CS.setFieldWidth(Amt);
139 }
140 return false;
141 }
142
143 bool
ParseArgPosition(FormatStringHandler & H,FormatSpecifier & FS,const char * Start,const char * & Beg,const char * E)144 clang::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(I, E);
152
153 if (I == E) {
154 // No more characters left?
155 H.HandleIncompleteSpecifier(Start, E - Start);
156 return true;
157 }
158
159 if (Amt.getHowSpecified() == OptionalAmount::Constant && *(I++) == '$') {
160 // Warn that positional arguments are non-standard.
161 H.HandlePosition(Start, I - Start);
162
163 // Special case: '%0$', since this is an easy mistake.
164 if (Amt.getConstantAmount() == 0) {
165 H.HandleZeroPosition(Start, 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
180 bool
ParseVectorModifier(FormatStringHandler & H,FormatSpecifier & FS,const char * & I,const char * E,const LangOptions & LO)181 clang::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(Start, E - Start);
195 return true;
196 }
197
198 OptionalAmount NumElts = ParseAmount(I, E);
199 if (NumElts.getHowSpecified() != OptionalAmount::Constant) {
200 H.HandleIncompleteSpecifier(Start, E - Start);
201 return true;
202 }
203
204 FS.setVectorNumElts(NumElts);
205 }
206
207 return false;
208 }
209
210 bool
ParseLengthModifier(FormatSpecifier & FS,const char * & I,const char * E,const LangOptions & LO,bool IsScanf)211 clang::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
ParseUTF8InvalidSpecifier(const char * SpecifierBegin,const char * FmtStrEnd,unsigned & Len)296 bool 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);
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
323 clang::analyze_format_string::ArgType::MatchKind
matchesType(ASTContext & C,QualType argTy) const324 ArgType::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(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'.
355 if (!ETy->getDecl()->isComplete())
356 return NoMatch;
357 argTy = ETy->getDecl()->getIntegerType();
358 }
359
360 if (const auto *BT = argTy->getAs<BuiltinType>()) {
361 // The types are perfectly matched?
362 switch (BT->getKind()) {
363 default:
364 break;
365 case BuiltinType::Char_S:
366 case BuiltinType::SChar:
367 case BuiltinType::UChar:
368 case BuiltinType::Char_U:
369 case BuiltinType::Bool:
370 return Match;
371 }
372 // "Partially matched" because of promotions?
373 if (!Ptr) {
374 switch (BT->getKind()) {
375 default:
376 break;
377 case BuiltinType::Int:
378 case BuiltinType::UInt:
379 return MatchPromotion;
380 case BuiltinType::Short:
381 case BuiltinType::UShort:
382 case BuiltinType::WChar_S:
383 case BuiltinType::WChar_U:
384 return NoMatchPromotionTypeConfusion;
385 }
386 }
387 }
388 return NoMatch;
389 }
390
391 case SpecificTy: {
392 if (const EnumType *ETy = argTy->getAs<EnumType>()) {
393 // If the enum is incomplete we know nothing about the underlying type.
394 // Assume that it's 'int'.
395 if (!ETy->getDecl()->isComplete())
396 argTy = C.IntTy;
397 else
398 argTy = ETy->getDecl()->getIntegerType();
399 }
400 argTy = C.getCanonicalType(argTy).getUnqualifiedType();
401
402 if (T == argTy)
403 return Match;
404 if (const auto *BT = argTy->getAs<BuiltinType>()) {
405 // Check if the only difference between them is signed vs unsigned
406 // if true, we consider they are compatible.
407 switch (BT->getKind()) {
408 default:
409 break;
410 case BuiltinType::Char_S:
411 case BuiltinType::SChar:
412 case BuiltinType::Char_U:
413 case BuiltinType::UChar:
414 case BuiltinType::Bool:
415 if (T == C.UnsignedShortTy || T == C.ShortTy)
416 return NoMatchTypeConfusion;
417 if (T == C.UnsignedCharTy || T == C.SignedCharTy)
418 return Match;
419 break;
420 case BuiltinType::Short:
421 if (T == C.UnsignedShortTy)
422 return Match;
423 break;
424 case BuiltinType::UShort:
425 if (T == C.ShortTy)
426 return Match;
427 break;
428 case BuiltinType::Int:
429 if (T == C.UnsignedIntTy)
430 return Match;
431 break;
432 case BuiltinType::UInt:
433 if (T == C.IntTy)
434 return Match;
435 break;
436 case BuiltinType::Long:
437 if (T == C.UnsignedLongTy)
438 return Match;
439 break;
440 case BuiltinType::ULong:
441 if (T == C.LongTy)
442 return Match;
443 break;
444 case BuiltinType::LongLong:
445 if (T == C.UnsignedLongLongTy)
446 return Match;
447 break;
448 case BuiltinType::ULongLong:
449 if (T == C.LongLongTy)
450 return Match;
451 break;
452 }
453 // "Partially matched" because of promotions?
454 if (!Ptr) {
455 switch (BT->getKind()) {
456 default:
457 break;
458 case BuiltinType::Int:
459 case BuiltinType::UInt:
460 if (T == C.SignedCharTy || T == C.UnsignedCharTy ||
461 T == C.ShortTy || T == C.UnsignedShortTy || T == C.WCharTy ||
462 T == C.WideCharTy)
463 return MatchPromotion;
464 break;
465 case BuiltinType::Short:
466 case BuiltinType::UShort:
467 if (T == C.SignedCharTy || T == C.UnsignedCharTy)
468 return NoMatchPromotionTypeConfusion;
469 break;
470 case BuiltinType::WChar_U:
471 case BuiltinType::WChar_S:
472 if (T != C.WCharTy && T != C.WideCharTy)
473 return NoMatchPromotionTypeConfusion;
474 }
475 }
476 }
477 return NoMatch;
478 }
479
480 case CStrTy: {
481 const PointerType *PT = argTy->getAs<PointerType>();
482 if (!PT)
483 return NoMatch;
484 QualType pointeeTy = PT->getPointeeType();
485 if (const BuiltinType *BT = pointeeTy->getAs<BuiltinType>())
486 switch (BT->getKind()) {
487 case BuiltinType::Char_U:
488 case BuiltinType::UChar:
489 case BuiltinType::Char_S:
490 case BuiltinType::SChar:
491 return Match;
492 default:
493 break;
494 }
495
496 return NoMatch;
497 }
498
499 case WCStrTy: {
500 const PointerType *PT = argTy->getAs<PointerType>();
501 if (!PT)
502 return NoMatch;
503 QualType pointeeTy =
504 C.getCanonicalType(PT->getPointeeType()).getUnqualifiedType();
505 return pointeeTy == C.getWideCharType() ? Match : NoMatch;
506 }
507
508 case WIntTy: {
509 QualType WInt = C.getCanonicalType(C.getWIntType()).getUnqualifiedType();
510
511 if (C.getCanonicalType(argTy).getUnqualifiedType() == WInt)
512 return Match;
513
514 QualType PromoArg = C.isPromotableIntegerType(argTy)
515 ? C.getPromotedIntegerType(argTy)
516 : argTy;
517 PromoArg = C.getCanonicalType(PromoArg).getUnqualifiedType();
518
519 // If the promoted argument is the corresponding signed type of the
520 // wint_t type, then it should match.
521 if (PromoArg->hasSignedIntegerRepresentation() &&
522 C.getCorrespondingUnsignedType(PromoArg) == WInt)
523 return Match;
524
525 return WInt == PromoArg ? Match : NoMatch;
526 }
527
528 case CPointerTy:
529 if (argTy->isVoidPointerType()) {
530 return Match;
531 } if (argTy->isPointerType() || argTy->isObjCObjectPointerType() ||
532 argTy->isBlockPointerType() || argTy->isNullPtrType()) {
533 return NoMatchPedantic;
534 } else {
535 return NoMatch;
536 }
537
538 case ObjCPointerTy: {
539 if (argTy->getAs<ObjCObjectPointerType>() ||
540 argTy->getAs<BlockPointerType>())
541 return Match;
542
543 // Handle implicit toll-free bridging.
544 if (const PointerType *PT = argTy->getAs<PointerType>()) {
545 // Things such as CFTypeRef are really just opaque pointers
546 // to C structs representing CF types that can often be bridged
547 // to Objective-C objects. Since the compiler doesn't know which
548 // structs can be toll-free bridged, we just accept them all.
549 QualType pointee = PT->getPointeeType();
550 if (pointee->getAsStructureType() || pointee->isVoidType())
551 return Match;
552 }
553 return NoMatch;
554 }
555 }
556
557 llvm_unreachable("Invalid ArgType Kind!");
558 }
559
makeVectorType(ASTContext & C,unsigned NumElts) const560 ArgType ArgType::makeVectorType(ASTContext &C, unsigned NumElts) const {
561 // Check for valid vector element types.
562 if (T.isNull())
563 return ArgType::Invalid();
564
565 QualType Vec = C.getExtVectorType(T, NumElts);
566 return ArgType(Vec, Name);
567 }
568
getRepresentativeType(ASTContext & C) const569 QualType ArgType::getRepresentativeType(ASTContext &C) const {
570 QualType Res;
571 switch (K) {
572 case InvalidTy:
573 llvm_unreachable("No representative type for Invalid ArgType");
574 case UnknownTy:
575 llvm_unreachable("No representative type for Unknown ArgType");
576 case AnyCharTy:
577 Res = C.CharTy;
578 break;
579 case SpecificTy:
580 Res = T;
581 break;
582 case CStrTy:
583 Res = C.getPointerType(C.CharTy);
584 break;
585 case WCStrTy:
586 Res = C.getPointerType(C.getWideCharType());
587 break;
588 case ObjCPointerTy:
589 Res = C.ObjCBuiltinIdTy;
590 break;
591 case CPointerTy:
592 Res = C.VoidPtrTy;
593 break;
594 case WIntTy: {
595 Res = C.getWIntType();
596 break;
597 }
598 }
599
600 if (Ptr)
601 Res = C.getPointerType(Res);
602 return Res;
603 }
604
getRepresentativeTypeName(ASTContext & C) const605 std::string ArgType::getRepresentativeTypeName(ASTContext &C) const {
606 std::string S = getRepresentativeType(C).getAsString(C.getPrintingPolicy());
607
608 std::string Alias;
609 if (Name) {
610 // Use a specific name for this type, e.g. "size_t".
611 Alias = Name;
612 if (Ptr) {
613 // If ArgType is actually a pointer to T, append an asterisk.
614 Alias += (Alias[Alias.size()-1] == '*') ? "*" : " *";
615 }
616 // If Alias is the same as the underlying type, e.g. wchar_t, then drop it.
617 if (S == Alias)
618 Alias.clear();
619 }
620
621 if (!Alias.empty())
622 return std::string("'") + Alias + "' (aka '" + S + "')";
623 return std::string("'") + S + "'";
624 }
625
626
627 //===----------------------------------------------------------------------===//
628 // Methods on OptionalAmount.
629 //===----------------------------------------------------------------------===//
630
631 ArgType
getArgType(ASTContext & Ctx) const632 analyze_format_string::OptionalAmount::getArgType(ASTContext &Ctx) const {
633 return Ctx.IntTy;
634 }
635
636 //===----------------------------------------------------------------------===//
637 // Methods on LengthModifier.
638 //===----------------------------------------------------------------------===//
639
640 const char *
toString() const641 analyze_format_string::LengthModifier::toString() const {
642 switch (kind) {
643 case AsChar:
644 return "hh";
645 case AsShort:
646 return "h";
647 case AsShortLong:
648 return "hl";
649 case AsLong: // or AsWideChar
650 return "l";
651 case AsLongLong:
652 return "ll";
653 case AsQuad:
654 return "q";
655 case AsIntMax:
656 return "j";
657 case AsSizeT:
658 return "z";
659 case AsPtrDiff:
660 return "t";
661 case AsInt32:
662 return "I32";
663 case AsInt3264:
664 return "I";
665 case AsInt64:
666 return "I64";
667 case AsLongDouble:
668 return "L";
669 case AsAllocate:
670 return "a";
671 case AsMAllocate:
672 return "m";
673 case AsWide:
674 return "w";
675 case None:
676 return "";
677 }
678 return nullptr;
679 }
680
681 //===----------------------------------------------------------------------===//
682 // Methods on ConversionSpecifier.
683 //===----------------------------------------------------------------------===//
684
toString() const685 const char *ConversionSpecifier::toString() const {
686 switch (kind) {
687 case bArg: return "b";
688 case BArg: return "B";
689 case dArg: return "d";
690 case DArg: return "D";
691 case iArg: return "i";
692 case oArg: return "o";
693 case OArg: return "O";
694 case uArg: return "u";
695 case UArg: return "U";
696 case xArg: return "x";
697 case XArg: return "X";
698 case fArg: return "f";
699 case FArg: return "F";
700 case eArg: return "e";
701 case EArg: return "E";
702 case gArg: return "g";
703 case GArg: return "G";
704 case aArg: return "a";
705 case AArg: return "A";
706 case cArg: return "c";
707 case sArg: return "s";
708 case pArg: return "p";
709 case PArg:
710 return "P";
711 case nArg: return "n";
712 case PercentArg: return "%";
713 case ScanListArg: return "[";
714 case InvalidSpecifier: return nullptr;
715
716 // POSIX unicode extensions.
717 case CArg: return "C";
718 case SArg: return "S";
719
720 // Objective-C specific specifiers.
721 case ObjCObjArg: return "@";
722
723 // FreeBSD kernel specific specifiers.
724 case FreeBSDbArg: return "b";
725 case FreeBSDDArg: return "D";
726 case FreeBSDrArg: return "r";
727 case FreeBSDyArg: return "y";
728
729 // GlibC specific specifiers.
730 case PrintErrno: return "m";
731
732 // MS specific specifiers.
733 case ZArg: return "Z";
734 }
735 return nullptr;
736 }
737
738 std::optional<ConversionSpecifier>
getStandardSpecifier() const739 ConversionSpecifier::getStandardSpecifier() const {
740 ConversionSpecifier::Kind NewKind;
741
742 switch (getKind()) {
743 default:
744 return std::nullopt;
745 case DArg:
746 NewKind = dArg;
747 break;
748 case UArg:
749 NewKind = uArg;
750 break;
751 case OArg:
752 NewKind = oArg;
753 break;
754 }
755
756 ConversionSpecifier FixedCS(*this);
757 FixedCS.setKind(NewKind);
758 return FixedCS;
759 }
760
761 //===----------------------------------------------------------------------===//
762 // Methods on OptionalAmount.
763 //===----------------------------------------------------------------------===//
764
toString(raw_ostream & os) const765 void OptionalAmount::toString(raw_ostream &os) const {
766 switch (hs) {
767 case Invalid:
768 case NotSpecified:
769 return;
770 case Arg:
771 if (UsesDotPrefix)
772 os << ".";
773 if (usesPositionalArg())
774 os << "*" << getPositionalArgIndex() << "$";
775 else
776 os << "*";
777 break;
778 case Constant:
779 if (UsesDotPrefix)
780 os << ".";
781 os << amt;
782 break;
783 }
784 }
785
hasValidLengthModifier(const TargetInfo & Target,const LangOptions & LO) const786 bool FormatSpecifier::hasValidLengthModifier(const TargetInfo &Target,
787 const LangOptions &LO) const {
788 switch (LM.getKind()) {
789 case LengthModifier::None:
790 return true;
791
792 // Handle most integer flags
793 case LengthModifier::AsShort:
794 // Length modifier only applies to FP vectors.
795 if (LO.OpenCL && CS.isDoubleArg())
796 return !VectorNumElts.isInvalid();
797
798 if (Target.getTriple().isOSMSVCRT()) {
799 switch (CS.getKind()) {
800 case ConversionSpecifier::cArg:
801 case ConversionSpecifier::CArg:
802 case ConversionSpecifier::sArg:
803 case ConversionSpecifier::SArg:
804 case ConversionSpecifier::ZArg:
805 return true;
806 default:
807 break;
808 }
809 }
810 [[fallthrough]];
811 case LengthModifier::AsChar:
812 case LengthModifier::AsLongLong:
813 case LengthModifier::AsQuad:
814 case LengthModifier::AsIntMax:
815 case LengthModifier::AsSizeT:
816 case LengthModifier::AsPtrDiff:
817 switch (CS.getKind()) {
818 case ConversionSpecifier::bArg:
819 case ConversionSpecifier::BArg:
820 case ConversionSpecifier::dArg:
821 case ConversionSpecifier::DArg:
822 case ConversionSpecifier::iArg:
823 case ConversionSpecifier::oArg:
824 case ConversionSpecifier::OArg:
825 case ConversionSpecifier::uArg:
826 case ConversionSpecifier::UArg:
827 case ConversionSpecifier::xArg:
828 case ConversionSpecifier::XArg:
829 case ConversionSpecifier::nArg:
830 return true;
831 case ConversionSpecifier::FreeBSDbArg:
832 return Target.getTriple().isOSFreeBSD() ||
833 Target.getTriple().isPS4() ||
834 Target.getTriple().isOSOpenBSD();
835 case ConversionSpecifier::FreeBSDrArg:
836 case ConversionSpecifier::FreeBSDyArg:
837 return Target.getTriple().isOSFreeBSD() || Target.getTriple().isPS();
838 default:
839 return false;
840 }
841
842 case LengthModifier::AsShortLong:
843 return LO.OpenCL && !VectorNumElts.isInvalid();
844
845 // Handle 'l' flag
846 case LengthModifier::AsLong: // or AsWideChar
847 if (CS.isDoubleArg()) {
848 // Invalid for OpenCL FP scalars.
849 if (LO.OpenCL && VectorNumElts.isInvalid())
850 return false;
851 return true;
852 }
853
854 switch (CS.getKind()) {
855 case ConversionSpecifier::dArg:
856 case ConversionSpecifier::DArg:
857 case ConversionSpecifier::iArg:
858 case ConversionSpecifier::oArg:
859 case ConversionSpecifier::OArg:
860 case ConversionSpecifier::uArg:
861 case ConversionSpecifier::UArg:
862 case ConversionSpecifier::xArg:
863 case ConversionSpecifier::XArg:
864 case ConversionSpecifier::nArg:
865 case ConversionSpecifier::cArg:
866 case ConversionSpecifier::sArg:
867 case ConversionSpecifier::ScanListArg:
868 case ConversionSpecifier::ZArg:
869 return true;
870 case ConversionSpecifier::FreeBSDbArg:
871 return Target.getTriple().isOSFreeBSD() ||
872 Target.getTriple().isPS4() ||
873 Target.getTriple().isOSOpenBSD();
874 case ConversionSpecifier::FreeBSDrArg:
875 case ConversionSpecifier::FreeBSDyArg:
876 return Target.getTriple().isOSFreeBSD() || Target.getTriple().isPS();
877 default:
878 return false;
879 }
880
881 case LengthModifier::AsLongDouble:
882 switch (CS.getKind()) {
883 case ConversionSpecifier::aArg:
884 case ConversionSpecifier::AArg:
885 case ConversionSpecifier::fArg:
886 case ConversionSpecifier::FArg:
887 case ConversionSpecifier::eArg:
888 case ConversionSpecifier::EArg:
889 case ConversionSpecifier::gArg:
890 case ConversionSpecifier::GArg:
891 return true;
892 // GNU libc extension.
893 case ConversionSpecifier::dArg:
894 case ConversionSpecifier::iArg:
895 case ConversionSpecifier::oArg:
896 case ConversionSpecifier::uArg:
897 case ConversionSpecifier::xArg:
898 case ConversionSpecifier::XArg:
899 return !Target.getTriple().isOSDarwin() &&
900 !Target.getTriple().isOSWindows();
901 default:
902 return false;
903 }
904
905 case LengthModifier::AsAllocate:
906 switch (CS.getKind()) {
907 case ConversionSpecifier::sArg:
908 case ConversionSpecifier::SArg:
909 case ConversionSpecifier::ScanListArg:
910 return true;
911 default:
912 return false;
913 }
914
915 case LengthModifier::AsMAllocate:
916 switch (CS.getKind()) {
917 case ConversionSpecifier::cArg:
918 case ConversionSpecifier::CArg:
919 case ConversionSpecifier::sArg:
920 case ConversionSpecifier::SArg:
921 case ConversionSpecifier::ScanListArg:
922 return true;
923 default:
924 return false;
925 }
926 case LengthModifier::AsInt32:
927 case LengthModifier::AsInt3264:
928 case LengthModifier::AsInt64:
929 switch (CS.getKind()) {
930 case ConversionSpecifier::dArg:
931 case ConversionSpecifier::iArg:
932 case ConversionSpecifier::oArg:
933 case ConversionSpecifier::uArg:
934 case ConversionSpecifier::xArg:
935 case ConversionSpecifier::XArg:
936 return Target.getTriple().isOSMSVCRT();
937 default:
938 return false;
939 }
940 case LengthModifier::AsWide:
941 switch (CS.getKind()) {
942 case ConversionSpecifier::cArg:
943 case ConversionSpecifier::CArg:
944 case ConversionSpecifier::sArg:
945 case ConversionSpecifier::SArg:
946 case ConversionSpecifier::ZArg:
947 return Target.getTriple().isOSMSVCRT();
948 default:
949 return false;
950 }
951 }
952 llvm_unreachable("Invalid LengthModifier Kind!");
953 }
954
hasStandardLengthModifier() const955 bool FormatSpecifier::hasStandardLengthModifier() const {
956 switch (LM.getKind()) {
957 case LengthModifier::None:
958 case LengthModifier::AsChar:
959 case LengthModifier::AsShort:
960 case LengthModifier::AsLong:
961 case LengthModifier::AsLongLong:
962 case LengthModifier::AsIntMax:
963 case LengthModifier::AsSizeT:
964 case LengthModifier::AsPtrDiff:
965 case LengthModifier::AsLongDouble:
966 return true;
967 case LengthModifier::AsAllocate:
968 case LengthModifier::AsMAllocate:
969 case LengthModifier::AsQuad:
970 case LengthModifier::AsInt32:
971 case LengthModifier::AsInt3264:
972 case LengthModifier::AsInt64:
973 case LengthModifier::AsWide:
974 case LengthModifier::AsShortLong: // ???
975 return false;
976 }
977 llvm_unreachable("Invalid LengthModifier Kind!");
978 }
979
hasStandardConversionSpecifier(const LangOptions & LangOpt) const980 bool FormatSpecifier::hasStandardConversionSpecifier(
981 const LangOptions &LangOpt) const {
982 switch (CS.getKind()) {
983 case ConversionSpecifier::bArg:
984 case ConversionSpecifier::BArg:
985 case ConversionSpecifier::cArg:
986 case ConversionSpecifier::dArg:
987 case ConversionSpecifier::iArg:
988 case ConversionSpecifier::oArg:
989 case ConversionSpecifier::uArg:
990 case ConversionSpecifier::xArg:
991 case ConversionSpecifier::XArg:
992 case ConversionSpecifier::fArg:
993 case ConversionSpecifier::FArg:
994 case ConversionSpecifier::eArg:
995 case ConversionSpecifier::EArg:
996 case ConversionSpecifier::gArg:
997 case ConversionSpecifier::GArg:
998 case ConversionSpecifier::aArg:
999 case ConversionSpecifier::AArg:
1000 case ConversionSpecifier::sArg:
1001 case ConversionSpecifier::pArg:
1002 case ConversionSpecifier::nArg:
1003 case ConversionSpecifier::ObjCObjArg:
1004 case ConversionSpecifier::ScanListArg:
1005 case ConversionSpecifier::PercentArg:
1006 case ConversionSpecifier::PArg:
1007 return true;
1008 case ConversionSpecifier::CArg:
1009 case ConversionSpecifier::SArg:
1010 return LangOpt.ObjC;
1011 case ConversionSpecifier::InvalidSpecifier:
1012 case ConversionSpecifier::FreeBSDbArg:
1013 case ConversionSpecifier::FreeBSDDArg:
1014 case ConversionSpecifier::FreeBSDrArg:
1015 case ConversionSpecifier::FreeBSDyArg:
1016 case ConversionSpecifier::PrintErrno:
1017 case ConversionSpecifier::DArg:
1018 case ConversionSpecifier::OArg:
1019 case ConversionSpecifier::UArg:
1020 case ConversionSpecifier::ZArg:
1021 return false;
1022 }
1023 llvm_unreachable("Invalid ConversionSpecifier Kind!");
1024 }
1025
hasStandardLengthConversionCombination() const1026 bool FormatSpecifier::hasStandardLengthConversionCombination() const {
1027 if (LM.getKind() == LengthModifier::AsLongDouble) {
1028 switch(CS.getKind()) {
1029 case ConversionSpecifier::dArg:
1030 case ConversionSpecifier::iArg:
1031 case ConversionSpecifier::oArg:
1032 case ConversionSpecifier::uArg:
1033 case ConversionSpecifier::xArg:
1034 case ConversionSpecifier::XArg:
1035 case ConversionSpecifier::FreeBSDbArg:
1036 return false;
1037 default:
1038 return true;
1039 }
1040 }
1041 return true;
1042 }
1043
1044 std::optional<LengthModifier>
getCorrectedLengthModifier() const1045 FormatSpecifier::getCorrectedLengthModifier() const {
1046 if (CS.isAnyIntArg() || CS.getKind() == ConversionSpecifier::nArg) {
1047 if (LM.getKind() == LengthModifier::AsLongDouble ||
1048 LM.getKind() == LengthModifier::AsQuad) {
1049 LengthModifier FixedLM(LM);
1050 FixedLM.setKind(LengthModifier::AsLongLong);
1051 return FixedLM;
1052 }
1053 }
1054
1055 return std::nullopt;
1056 }
1057
namedTypeToLengthModifier(QualType QT,LengthModifier & LM)1058 bool FormatSpecifier::namedTypeToLengthModifier(QualType QT,
1059 LengthModifier &LM) {
1060 for (/**/; const auto *TT = QT->getAs<TypedefType>();
1061 QT = TT->getDecl()->getUnderlyingType()) {
1062 const TypedefNameDecl *Typedef = TT->getDecl();
1063 const IdentifierInfo *Identifier = Typedef->getIdentifier();
1064 if (Identifier->getName() == "size_t") {
1065 LM.setKind(LengthModifier::AsSizeT);
1066 return true;
1067 } else if (Identifier->getName() == "ssize_t") {
1068 // Not C99, but common in Unix.
1069 LM.setKind(LengthModifier::AsSizeT);
1070 return true;
1071 } else if (Identifier->getName() == "intmax_t") {
1072 LM.setKind(LengthModifier::AsIntMax);
1073 return true;
1074 } else if (Identifier->getName() == "uintmax_t") {
1075 LM.setKind(LengthModifier::AsIntMax);
1076 return true;
1077 } else if (Identifier->getName() == "ptrdiff_t") {
1078 LM.setKind(LengthModifier::AsPtrDiff);
1079 return true;
1080 }
1081 }
1082 return false;
1083 }
1084