1 // FormatString.cpp - Common stuff for handling printf/scanf formats -*- C++ -*-
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Shared details for processing format strings of printf and scanf
13 //===----------------------------------------------------------------------===//
15 #include "FormatStringParsing.h"
16 #include "clang/Basic/LangOptions.h"
18 using clang::analyze_format_string::ArgTypeResult;
19 using clang::analyze_format_string::FormatStringHandler;
20 using clang::analyze_format_string::FormatSpecifier;
21 using clang::analyze_format_string::LengthModifier;
22 using clang::analyze_format_string::OptionalAmount;
23 using clang::analyze_format_string::PositionContext;
24 using clang::analyze_format_string::ConversionSpecifier;
25 using namespace clang;
27 // Key function to FormatStringHandler.
28 FormatStringHandler::~FormatStringHandler() {}
30 //===----------------------------------------------------------------------===//
31 // Functions for parsing format strings components in both printf and
32 // scanf format strings.
33 //===----------------------------------------------------------------------===//
36 clang::analyze_format_string::ParseAmount(const char *&Beg, const char *E) {
38 UpdateOnReturn <const char*> UpdateBeg(Beg, I);
40 unsigned accumulator = 0;
41 bool hasDigits = false;
43 for ( ; I != E; ++I) {
45 if (c >= '0' && c <= '9') {
47 accumulator = (accumulator * 10) + (c - '0');
52 return OptionalAmount(OptionalAmount::Constant, accumulator, Beg, I - Beg,
58 return OptionalAmount();
62 clang::analyze_format_string::ParseNonPositionAmount(const char *&Beg,
67 return OptionalAmount(OptionalAmount::Arg, argIndex++, Beg, 0, false);
70 return ParseAmount(Beg, E);
74 clang::analyze_format_string::ParsePositionAmount(FormatStringHandler &H,
80 const char *I = Beg + 1;
81 const OptionalAmount &Amt = ParseAmount(I, E);
83 if (Amt.getHowSpecified() == OptionalAmount::NotSpecified) {
84 H.HandleInvalidPosition(Beg, I - Beg, p);
85 return OptionalAmount(false);
89 // No more characters left?
90 H.HandleIncompleteSpecifier(Start, E - Start);
91 return OptionalAmount(false);
94 assert(Amt.getHowSpecified() == OptionalAmount::Constant);
97 // Handle positional arguments
99 // Special case: '*0$', since this is an easy mistake.
100 if (Amt.getConstantAmount() == 0) {
101 H.HandleZeroPosition(Beg, I - Beg + 1);
102 return OptionalAmount(false);
105 const char *Tmp = Beg;
108 return OptionalAmount(OptionalAmount::Arg, Amt.getConstantAmount() - 1,
112 H.HandleInvalidPosition(Beg, I - Beg, p);
113 return OptionalAmount(false);
116 return ParseAmount(Beg, E);
121 clang::analyze_format_string::ParseFieldWidth(FormatStringHandler &H,
124 const char *&Beg, const char *E,
125 unsigned *argIndex) {
126 // FIXME: Support negative field widths.
128 CS.setFieldWidth(ParseNonPositionAmount(Beg, E, *argIndex));
131 const OptionalAmount Amt =
132 ParsePositionAmount(H, Start, Beg, E,
133 analyze_format_string::FieldWidthPos);
137 CS.setFieldWidth(Amt);
143 clang::analyze_format_string::ParseArgPosition(FormatStringHandler &H,
150 const OptionalAmount &Amt = ParseAmount(I, E);
153 // No more characters left?
154 H.HandleIncompleteSpecifier(Start, E - Start);
158 if (Amt.getHowSpecified() == OptionalAmount::Constant && *(I++) == '$') {
159 // Warn that positional arguments are non-standard.
160 H.HandlePosition(Start, I - Start);
162 // Special case: '%0$', since this is an easy mistake.
163 if (Amt.getConstantAmount() == 0) {
164 H.HandleZeroPosition(Start, I - Start);
168 FS.setArgIndex(Amt.getConstantAmount() - 1);
169 FS.setUsesPositionalArg();
170 // Update the caller's pointer if we decided to consume
180 clang::analyze_format_string::ParseLengthModifier(FormatSpecifier &FS,
183 const LangOptions &LO,
185 LengthModifier::Kind lmKind = LengthModifier::None;
186 const char *lmPosition = I;
192 lmKind = (I != E && *I == 'h') ? (++I, LengthModifier::AsChar)
193 : LengthModifier::AsShort;
197 lmKind = (I != E && *I == 'l') ? (++I, LengthModifier::AsLongLong)
198 : LengthModifier::AsLong;
200 case 'j': lmKind = LengthModifier::AsIntMax; ++I; break;
201 case 'z': lmKind = LengthModifier::AsSizeT; ++I; break;
202 case 't': lmKind = LengthModifier::AsPtrDiff; ++I; break;
203 case 'L': lmKind = LengthModifier::AsLongDouble; ++I; break;
204 case 'q': lmKind = LengthModifier::AsQuad; ++I; break;
206 if (IsScanf && !LO.C99 && !LO.CPlusPlus0x) {
207 // For scanf in C90, look at the next character to see if this should
208 // be parsed as the GNU extension 'a' length modifier. If not, this
209 // will be parsed as a conversion specifier.
211 if (I != E && (*I == 's' || *I == 'S' || *I == '[')) {
212 lmKind = LengthModifier::AsAllocate;
220 lmKind = LengthModifier::AsMAllocate;
226 LengthModifier lm(lmPosition, lmKind);
227 FS.setLengthModifier(lm);
231 //===----------------------------------------------------------------------===//
232 // Methods on ArgTypeResult.
233 //===----------------------------------------------------------------------===//
235 bool ArgTypeResult::matchesType(ASTContext &C, QualType argTy) const {
238 llvm_unreachable("ArgTypeResult must be valid");
244 if (const BuiltinType *BT = argTy->getAs<BuiltinType>())
245 switch (BT->getKind()) {
248 case BuiltinType::Char_S:
249 case BuiltinType::SChar:
250 case BuiltinType::UChar:
251 case BuiltinType::Char_U:
258 argTy = C.getCanonicalType(argTy).getUnqualifiedType();
261 // Check for "compatible types".
262 if (const BuiltinType *BT = argTy->getAs<BuiltinType>())
263 switch (BT->getKind()) {
266 case BuiltinType::Char_S:
267 case BuiltinType::SChar:
268 return T == C.UnsignedCharTy;
269 case BuiltinType::Char_U:
270 case BuiltinType::UChar:
271 return T == C.SignedCharTy;
272 case BuiltinType::Short:
273 return T == C.UnsignedShortTy;
274 case BuiltinType::UShort:
275 return T == C.ShortTy;
276 case BuiltinType::Int:
277 return T == C.UnsignedIntTy;
278 case BuiltinType::UInt:
280 case BuiltinType::Long:
281 return T == C.UnsignedLongTy;
282 case BuiltinType::ULong:
283 return T == C.LongTy;
284 case BuiltinType::LongLong:
285 return T == C.UnsignedLongLongTy;
286 case BuiltinType::ULongLong:
287 return T == C.LongLongTy;
293 const PointerType *PT = argTy->getAs<PointerType>();
296 QualType pointeeTy = PT->getPointeeType();
297 if (const BuiltinType *BT = pointeeTy->getAs<BuiltinType>())
298 switch (BT->getKind()) {
299 case BuiltinType::Void:
300 case BuiltinType::Char_U:
301 case BuiltinType::UChar:
302 case BuiltinType::Char_S:
303 case BuiltinType::SChar:
313 const PointerType *PT = argTy->getAs<PointerType>();
317 C.getCanonicalType(PT->getPointeeType()).getUnqualifiedType();
318 return pointeeTy == C.getWCharType();
322 // Instead of doing a lookup for the definition of 'wint_t' (which
323 // is defined by the system headers) instead see if wchar_t and
324 // the argument type promote to the same type.
325 QualType PromoWChar =
326 C.getWCharType()->isPromotableIntegerType()
327 ? C.getPromotedIntegerType(C.getWCharType()) : C.getWCharType();
329 argTy->isPromotableIntegerType()
330 ? C.getPromotedIntegerType(argTy) : argTy;
332 PromoWChar = C.getCanonicalType(PromoWChar).getUnqualifiedType();
333 PromoArg = C.getCanonicalType(PromoArg).getUnqualifiedType();
335 return PromoWChar == PromoArg;
339 return argTy->isPointerType() || argTy->isObjCObjectPointerType() ||
340 argTy->isBlockPointerType() || argTy->isNullPtrType();
342 case ObjCPointerTy: {
343 if (argTy->getAs<ObjCObjectPointerType>() ||
344 argTy->getAs<BlockPointerType>())
347 // Handle implicit toll-free bridging.
348 if (const PointerType *PT = argTy->getAs<PointerType>()) {
349 // Things such as CFTypeRef are really just opaque pointers
350 // to C structs representing CF types that can often be bridged
351 // to Objective-C objects. Since the compiler doesn't know which
352 // structs can be toll-free bridged, we just accept them all.
353 QualType pointee = PT->getPointeeType();
354 if (pointee->getAsStructureType() || pointee->isVoidType())
361 llvm_unreachable("Invalid ArgTypeResult Kind!");
364 QualType ArgTypeResult::getRepresentativeType(ASTContext &C) const {
367 llvm_unreachable("No representative type for Invalid ArgTypeResult");
375 return C.getPointerType(C.CharTy);
377 return C.getPointerType(C.getWCharType());
379 return C.ObjCBuiltinIdTy;
383 QualType WC = C.getWCharType();
384 return WC->isPromotableIntegerType() ? C.getPromotedIntegerType(WC) : WC;
388 llvm_unreachable("Invalid ArgTypeResult Kind!");
391 std::string ArgTypeResult::getRepresentativeTypeName(ASTContext &C) const {
392 std::string S = getRepresentativeType(C).getAsString();
393 if (Name && S != Name)
394 return std::string("'") + Name + "' (aka '" + S + "')";
395 return std::string("'") + S + "'";
399 //===----------------------------------------------------------------------===//
400 // Methods on OptionalAmount.
401 //===----------------------------------------------------------------------===//
404 analyze_format_string::OptionalAmount::getArgType(ASTContext &Ctx) const {
408 //===----------------------------------------------------------------------===//
409 // Methods on LengthModifier.
410 //===----------------------------------------------------------------------===//
413 analyze_format_string::LengthModifier::toString() const {
419 case AsLong: // or AsWideChar
443 //===----------------------------------------------------------------------===//
444 // Methods on ConversionSpecifier.
445 //===----------------------------------------------------------------------===//
447 const char *ConversionSpecifier::toString() const {
449 case dArg: return "d";
450 case iArg: return "i";
451 case oArg: return "o";
452 case uArg: return "u";
453 case xArg: return "x";
454 case XArg: return "X";
455 case fArg: return "f";
456 case FArg: return "F";
457 case eArg: return "e";
458 case EArg: return "E";
459 case gArg: return "g";
460 case GArg: return "G";
461 case aArg: return "a";
462 case AArg: return "A";
463 case cArg: return "c";
464 case sArg: return "s";
465 case pArg: return "p";
466 case nArg: return "n";
467 case PercentArg: return "%";
468 case ScanListArg: return "[";
469 case InvalidSpecifier: return NULL;
471 // MacOS X unicode extensions.
472 case CArg: return "C";
473 case SArg: return "S";
475 // Objective-C specific specifiers.
476 case ObjCObjArg: return "@";
478 // FreeBSD specific specifiers.
479 case bArg: return "b";
480 case DArg: return "D";
481 case rArg: return "r";
483 // GlibC specific specifiers.
484 case PrintErrno: return "m";
489 //===----------------------------------------------------------------------===//
490 // Methods on OptionalAmount.
491 //===----------------------------------------------------------------------===//
493 void OptionalAmount::toString(raw_ostream &os) const {
501 if (usesPositionalArg())
502 os << "*" << getPositionalArgIndex() << "$";
514 bool FormatSpecifier::hasValidLengthModifier() const {
515 switch (LM.getKind()) {
516 case LengthModifier::None:
519 // Handle most integer flags
520 case LengthModifier::AsChar:
521 case LengthModifier::AsShort:
522 case LengthModifier::AsLongLong:
523 case LengthModifier::AsQuad:
524 case LengthModifier::AsIntMax:
525 case LengthModifier::AsSizeT:
526 case LengthModifier::AsPtrDiff:
527 switch (CS.getKind()) {
528 case ConversionSpecifier::dArg:
529 case ConversionSpecifier::iArg:
530 case ConversionSpecifier::oArg:
531 case ConversionSpecifier::uArg:
532 case ConversionSpecifier::xArg:
533 case ConversionSpecifier::XArg:
534 case ConversionSpecifier::nArg:
535 case ConversionSpecifier::rArg:
542 case LengthModifier::AsLong:
543 switch (CS.getKind()) {
544 case ConversionSpecifier::dArg:
545 case ConversionSpecifier::iArg:
546 case ConversionSpecifier::oArg:
547 case ConversionSpecifier::uArg:
548 case ConversionSpecifier::xArg:
549 case ConversionSpecifier::XArg:
550 case ConversionSpecifier::aArg:
551 case ConversionSpecifier::AArg:
552 case ConversionSpecifier::fArg:
553 case ConversionSpecifier::FArg:
554 case ConversionSpecifier::eArg:
555 case ConversionSpecifier::EArg:
556 case ConversionSpecifier::gArg:
557 case ConversionSpecifier::GArg:
558 case ConversionSpecifier::nArg:
559 case ConversionSpecifier::cArg:
560 case ConversionSpecifier::sArg:
561 case ConversionSpecifier::rArg:
562 case ConversionSpecifier::ScanListArg:
568 case LengthModifier::AsLongDouble:
569 switch (CS.getKind()) {
570 case ConversionSpecifier::aArg:
571 case ConversionSpecifier::AArg:
572 case ConversionSpecifier::fArg:
573 case ConversionSpecifier::FArg:
574 case ConversionSpecifier::eArg:
575 case ConversionSpecifier::EArg:
576 case ConversionSpecifier::gArg:
577 case ConversionSpecifier::GArg:
580 case ConversionSpecifier::dArg:
581 case ConversionSpecifier::iArg:
582 case ConversionSpecifier::oArg:
583 case ConversionSpecifier::uArg:
584 case ConversionSpecifier::xArg:
585 case ConversionSpecifier::XArg:
591 case LengthModifier::AsAllocate:
592 switch (CS.getKind()) {
593 case ConversionSpecifier::sArg:
594 case ConversionSpecifier::SArg:
595 case ConversionSpecifier::ScanListArg:
601 case LengthModifier::AsMAllocate:
602 switch (CS.getKind()) {
603 case ConversionSpecifier::cArg:
604 case ConversionSpecifier::CArg:
605 case ConversionSpecifier::sArg:
606 case ConversionSpecifier::SArg:
607 case ConversionSpecifier::ScanListArg:
613 llvm_unreachable("Invalid LengthModifier Kind!");
616 bool FormatSpecifier::hasStandardLengthModifier() const {
617 switch (LM.getKind()) {
618 case LengthModifier::None:
619 case LengthModifier::AsChar:
620 case LengthModifier::AsShort:
621 case LengthModifier::AsLong:
622 case LengthModifier::AsLongLong:
623 case LengthModifier::AsIntMax:
624 case LengthModifier::AsSizeT:
625 case LengthModifier::AsPtrDiff:
626 case LengthModifier::AsLongDouble:
628 case LengthModifier::AsAllocate:
629 case LengthModifier::AsMAllocate:
630 case LengthModifier::AsQuad:
633 llvm_unreachable("Invalid LengthModifier Kind!");
636 bool FormatSpecifier::hasStandardConversionSpecifier(const LangOptions &LangOpt) const {
637 switch (CS.getKind()) {
638 case ConversionSpecifier::cArg:
639 case ConversionSpecifier::dArg:
640 case ConversionSpecifier::iArg:
641 case ConversionSpecifier::oArg:
642 case ConversionSpecifier::uArg:
643 case ConversionSpecifier::xArg:
644 case ConversionSpecifier::XArg:
645 case ConversionSpecifier::fArg:
646 case ConversionSpecifier::FArg:
647 case ConversionSpecifier::eArg:
648 case ConversionSpecifier::EArg:
649 case ConversionSpecifier::gArg:
650 case ConversionSpecifier::GArg:
651 case ConversionSpecifier::aArg:
652 case ConversionSpecifier::AArg:
653 case ConversionSpecifier::sArg:
654 case ConversionSpecifier::pArg:
655 case ConversionSpecifier::nArg:
656 case ConversionSpecifier::ObjCObjArg:
657 case ConversionSpecifier::ScanListArg:
658 case ConversionSpecifier::PercentArg:
660 case ConversionSpecifier::CArg:
661 case ConversionSpecifier::SArg:
662 return LangOpt.ObjC1 || LangOpt.ObjC2;
663 case ConversionSpecifier::InvalidSpecifier:
664 case ConversionSpecifier::bArg:
665 case ConversionSpecifier::DArg:
666 case ConversionSpecifier::rArg:
667 case ConversionSpecifier::PrintErrno:
670 llvm_unreachable("Invalid ConversionSpecifier Kind!");
673 bool FormatSpecifier::hasStandardLengthConversionCombination() const {
674 if (LM.getKind() == LengthModifier::AsLongDouble) {
675 switch(CS.getKind()) {
676 case ConversionSpecifier::dArg:
677 case ConversionSpecifier::iArg:
678 case ConversionSpecifier::oArg:
679 case ConversionSpecifier::uArg:
680 case ConversionSpecifier::xArg:
681 case ConversionSpecifier::XArg: