1 //= FormatString.h - Analysis of printf/fprintf format strings --*- 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 // This file defines APIs for analyzing the format strings of printf, fscanf, 10 // and friends. 11 // 12 // The structure of format strings for fprintf are described in C99 7.19.6.1. 13 // 14 // The structure of format strings for fscanf are described in C99 7.19.6.2. 15 // 16 //===----------------------------------------------------------------------===// 17 18 #ifndef LLVM_CLANG_AST_FORMATSTRING_H 19 #define LLVM_CLANG_AST_FORMATSTRING_H 20 21 #include "clang/AST/CanonicalType.h" 22 #include <optional> 23 24 namespace clang { 25 26 class TargetInfo; 27 28 //===----------------------------------------------------------------------===// 29 /// Common components of both fprintf and fscanf format strings. 30 namespace analyze_format_string { 31 32 /// Class representing optional flags with location and representation 33 /// information. 34 class OptionalFlag { 35 public: OptionalFlag(const char * Representation)36 OptionalFlag(const char *Representation) 37 : representation(Representation), flag(false) {} isSet()38 bool isSet() const { return flag; } set()39 void set() { flag = true; } clear()40 void clear() { flag = false; } setPosition(const char * position)41 void setPosition(const char *position) { 42 assert(position); 43 flag = true; 44 this->position = position; 45 } getPosition()46 const char *getPosition() const { 47 assert(position); 48 return position; 49 } toString()50 const char *toString() const { return representation; } 51 52 // Overloaded operators for bool like qualities 53 explicit operator bool() const { return flag; } 54 OptionalFlag& operator=(const bool &rhs) { 55 flag = rhs; 56 return *this; // Return a reference to myself. 57 } 58 private: 59 const char *representation; 60 const char *position; 61 bool flag; 62 }; 63 64 /// Represents the length modifier in a format string in scanf/printf. 65 class LengthModifier { 66 public: 67 enum Kind { 68 None, 69 AsChar, // 'hh' 70 AsShort, // 'h' 71 AsShortLong, // 'hl' (OpenCL float/int vector element) 72 AsLong, // 'l' 73 AsLongLong, // 'll' 74 AsQuad, // 'q' (BSD, deprecated, for 64-bit integer types) 75 AsIntMax, // 'j' 76 AsSizeT, // 'z' 77 AsPtrDiff, // 't' 78 AsInt32, // 'I32' (MSVCRT, like __int32) 79 AsInt3264, // 'I' (MSVCRT, like __int3264 from MIDL) 80 AsInt64, // 'I64' (MSVCRT, like __int64) 81 AsLongDouble, // 'L' 82 AsAllocate, // for '%as', GNU extension to C90 scanf 83 AsMAllocate, // for '%ms', GNU extension to scanf 84 AsWide, // 'w' (MSVCRT, like l but only for c, C, s, S, or Z 85 AsWideChar = AsLong // for '%ls', only makes sense for printf 86 }; 87 LengthModifier()88 LengthModifier() 89 : Position(nullptr), kind(None) {} LengthModifier(const char * pos,Kind k)90 LengthModifier(const char *pos, Kind k) 91 : Position(pos), kind(k) {} 92 getStart()93 const char *getStart() const { 94 return Position; 95 } 96 getLength()97 unsigned getLength() const { 98 switch (kind) { 99 default: 100 return 1; 101 case AsLongLong: 102 case AsChar: 103 return 2; 104 case AsInt32: 105 case AsInt64: 106 return 3; 107 case None: 108 return 0; 109 } 110 } 111 getKind()112 Kind getKind() const { return kind; } setKind(Kind k)113 void setKind(Kind k) { kind = k; } 114 115 const char *toString() const; 116 117 private: 118 const char *Position; 119 Kind kind; 120 }; 121 122 class ConversionSpecifier { 123 public: 124 enum Kind { 125 InvalidSpecifier = 0, 126 // C99 conversion specifiers. 127 cArg, 128 dArg, 129 DArg, // Apple extension 130 iArg, 131 // C23 conversion specifiers. 132 bArg, 133 BArg, 134 135 IntArgBeg = dArg, 136 IntArgEnd = BArg, 137 138 oArg, 139 OArg, // Apple extension 140 uArg, 141 UArg, // Apple extension 142 xArg, 143 XArg, 144 UIntArgBeg = oArg, 145 UIntArgEnd = XArg, 146 147 fArg, 148 FArg, 149 eArg, 150 EArg, 151 gArg, 152 GArg, 153 aArg, 154 AArg, 155 DoubleArgBeg = fArg, 156 DoubleArgEnd = AArg, 157 158 sArg, 159 pArg, 160 nArg, 161 PercentArg, 162 CArg, 163 SArg, 164 165 // Apple extension: P specifies to os_log that the data being pointed to is 166 // to be copied by os_log. The precision indicates the number of bytes to 167 // copy. 168 PArg, 169 170 // ** Printf-specific ** 171 172 ZArg, // MS extension 173 174 // ISO/IEC TR 18037 (fixed-point) specific specifiers. 175 kArg, // %k for signed accum types 176 KArg, // %K for unsigned accum types 177 rArg, // %r for signed fract types 178 RArg, // %R for unsigned fract types 179 FixedPointArgBeg = kArg, 180 FixedPointArgEnd = RArg, 181 182 // Objective-C specific specifiers. 183 ObjCObjArg, // '@' 184 ObjCBeg = ObjCObjArg, 185 ObjCEnd = ObjCObjArg, 186 187 // FreeBSD kernel specific specifiers. 188 FreeBSDbArg, 189 FreeBSDDArg, 190 FreeBSDrArg, 191 FreeBSDyArg, 192 193 // GlibC specific specifiers. 194 PrintErrno, // 'm' 195 196 PrintfConvBeg = ObjCObjArg, 197 PrintfConvEnd = PrintErrno, 198 199 // ** Scanf-specific ** 200 ScanListArg, // '[' 201 ScanfConvBeg = ScanListArg, 202 ScanfConvEnd = ScanListArg 203 }; 204 205 ConversionSpecifier(bool isPrintf = true) IsPrintf(isPrintf)206 : IsPrintf(isPrintf), Position(nullptr), EndScanList(nullptr), 207 kind(InvalidSpecifier) {} 208 ConversionSpecifier(bool isPrintf,const char * pos,Kind k)209 ConversionSpecifier(bool isPrintf, const char *pos, Kind k) 210 : IsPrintf(isPrintf), Position(pos), EndScanList(nullptr), kind(k) {} 211 getStart()212 const char *getStart() const { 213 return Position; 214 } 215 getCharacters()216 StringRef getCharacters() const { 217 return StringRef(getStart(), getLength()); 218 } 219 consumesDataArgument()220 bool consumesDataArgument() const { 221 switch (kind) { 222 case PrintErrno: 223 assert(IsPrintf); 224 return false; 225 case PercentArg: 226 return false; 227 case InvalidSpecifier: 228 return false; 229 default: 230 return true; 231 } 232 } 233 getKind()234 Kind getKind() const { return kind; } setKind(Kind k)235 void setKind(Kind k) { kind = k; } getLength()236 unsigned getLength() const { 237 return EndScanList ? EndScanList - Position : 1; 238 } setEndScanList(const char * pos)239 void setEndScanList(const char *pos) { EndScanList = pos; } 240 isIntArg()241 bool isIntArg() const { return (kind >= IntArgBeg && kind <= IntArgEnd) || 242 kind == FreeBSDrArg || kind == FreeBSDyArg; } isUIntArg()243 bool isUIntArg() const { return kind >= UIntArgBeg && kind <= UIntArgEnd; } isAnyIntArg()244 bool isAnyIntArg() const { return kind >= IntArgBeg && kind <= UIntArgEnd; } isDoubleArg()245 bool isDoubleArg() const { 246 return kind >= DoubleArgBeg && kind <= DoubleArgEnd; 247 } isFixedPointArg()248 bool isFixedPointArg() const { 249 return kind >= FixedPointArgBeg && kind <= FixedPointArgEnd; 250 } 251 252 const char *toString() const; 253 isPrintfKind()254 bool isPrintfKind() const { return IsPrintf; } 255 256 std::optional<ConversionSpecifier> getStandardSpecifier() const; 257 258 protected: 259 bool IsPrintf; 260 const char *Position; 261 const char *EndScanList; 262 Kind kind; 263 }; 264 265 class ArgType { 266 public: 267 enum Kind { UnknownTy, InvalidTy, SpecificTy, ObjCPointerTy, CPointerTy, 268 AnyCharTy, CStrTy, WCStrTy, WIntTy }; 269 270 /// How well a given conversion specifier matches its argument. 271 enum MatchKind { 272 /// The conversion specifier and the argument types are incompatible. For 273 /// instance, "%d" and float. 274 NoMatch = 0, 275 /// The conversion specifier and the argument type are compatible. For 276 /// instance, "%d" and int. 277 Match = 1, 278 /// The conversion specifier and the argument type are compatible because of 279 /// default argument promotions. For instance, "%hhd" and int. 280 MatchPromotion, 281 /// The conversion specifier and the argument type are compatible but still 282 /// seems likely to be an error. For instanace, "%hhd" and short. 283 NoMatchPromotionTypeConfusion, 284 /// The conversion specifier and the argument type are disallowed by the C 285 /// standard, but are in practice harmless. For instance, "%p" and int*. 286 NoMatchPedantic, 287 /// The conversion specifier and the argument type have different sign. 288 NoMatchSignedness, 289 /// The conversion specifier and the argument type are compatible, but still 290 /// seems likely to be an error. For instance, "%hd" and _Bool. 291 NoMatchTypeConfusion, 292 }; 293 294 private: 295 const Kind K; 296 QualType T; 297 const char *Name = nullptr; 298 bool Ptr = false; 299 300 /// The TypeKind identifies certain well-known types like size_t and 301 /// ptrdiff_t. 302 enum class TypeKind { DontCare, SizeT, PtrdiffT }; 303 TypeKind TK = TypeKind::DontCare; 304 305 public: K(K)306 ArgType(Kind K = UnknownTy, const char *N = nullptr) : K(K), Name(N) {} K(SpecificTy)307 ArgType(QualType T, const char *N = nullptr) : K(SpecificTy), T(T), Name(N) {} ArgType(CanQualType T)308 ArgType(CanQualType T) : K(SpecificTy), T(T) {} 309 Invalid()310 static ArgType Invalid() { return ArgType(InvalidTy); } isValid()311 bool isValid() const { return K != InvalidTy; } 312 isSizeT()313 bool isSizeT() const { return TK == TypeKind::SizeT; } 314 isPtrdiffT()315 bool isPtrdiffT() const { return TK == TypeKind::PtrdiffT; } 316 317 /// Create an ArgType which corresponds to the type pointer to A. PtrTo(const ArgType & A)318 static ArgType PtrTo(const ArgType& A) { 319 assert(A.K >= InvalidTy && "ArgType cannot be pointer to invalid/unknown"); 320 ArgType Res = A; 321 Res.Ptr = true; 322 return Res; 323 } 324 325 /// Create an ArgType which corresponds to the size_t/ssize_t type. makeSizeT(const ArgType & A)326 static ArgType makeSizeT(const ArgType &A) { 327 ArgType Res = A; 328 Res.TK = TypeKind::SizeT; 329 return Res; 330 } 331 332 /// Create an ArgType which corresponds to the ptrdiff_t/unsigned ptrdiff_t 333 /// type. makePtrdiffT(const ArgType & A)334 static ArgType makePtrdiffT(const ArgType &A) { 335 ArgType Res = A; 336 Res.TK = TypeKind::PtrdiffT; 337 return Res; 338 } 339 340 MatchKind matchesType(ASTContext &C, QualType argTy) const; 341 342 QualType getRepresentativeType(ASTContext &C) const; 343 344 ArgType makeVectorType(ASTContext &C, unsigned NumElts) const; 345 346 std::string getRepresentativeTypeName(ASTContext &C) const; 347 }; 348 349 class OptionalAmount { 350 public: 351 enum HowSpecified { NotSpecified, Constant, Arg, Invalid }; 352 OptionalAmount(HowSpecified howSpecified,unsigned amount,const char * amountStart,unsigned amountLength,bool usesPositionalArg)353 OptionalAmount(HowSpecified howSpecified, 354 unsigned amount, 355 const char *amountStart, 356 unsigned amountLength, 357 bool usesPositionalArg) 358 : start(amountStart), length(amountLength), hs(howSpecified), amt(amount), 359 UsesPositionalArg(usesPositionalArg), UsesDotPrefix(false) {} 360 361 OptionalAmount(bool valid = true) start(nullptr)362 : start(nullptr),length(0), hs(valid ? NotSpecified : Invalid), amt(0), 363 UsesPositionalArg(false), UsesDotPrefix(false) {} 364 OptionalAmount(unsigned Amount)365 explicit OptionalAmount(unsigned Amount) 366 : start(nullptr), length(0), hs(Constant), amt(Amount), 367 UsesPositionalArg(false), UsesDotPrefix(false) {} 368 isInvalid()369 bool isInvalid() const { 370 return hs == Invalid; 371 } 372 getHowSpecified()373 HowSpecified getHowSpecified() const { return hs; } setHowSpecified(HowSpecified h)374 void setHowSpecified(HowSpecified h) { hs = h; } 375 hasDataArgument()376 bool hasDataArgument() const { return hs == Arg; } 377 getArgIndex()378 unsigned getArgIndex() const { 379 assert(hasDataArgument()); 380 return amt; 381 } 382 getConstantAmount()383 unsigned getConstantAmount() const { 384 assert(hs == Constant); 385 return amt; 386 } 387 getStart()388 const char *getStart() const { 389 // We include the . character if it is given. 390 return start - UsesDotPrefix; 391 } 392 getConstantLength()393 unsigned getConstantLength() const { 394 assert(hs == Constant); 395 return length + UsesDotPrefix; 396 } 397 398 ArgType getArgType(ASTContext &Ctx) const; 399 400 void toString(raw_ostream &os) const; 401 usesPositionalArg()402 bool usesPositionalArg() const { return (bool) UsesPositionalArg; } getPositionalArgIndex()403 unsigned getPositionalArgIndex() const { 404 assert(hasDataArgument()); 405 return amt + 1; 406 } 407 usesDotPrefix()408 bool usesDotPrefix() const { return UsesDotPrefix; } setUsesDotPrefix()409 void setUsesDotPrefix() { UsesDotPrefix = true; } 410 411 private: 412 const char *start; 413 unsigned length; 414 HowSpecified hs; 415 unsigned amt; 416 bool UsesPositionalArg : 1; 417 bool UsesDotPrefix; 418 }; 419 420 421 class FormatSpecifier { 422 protected: 423 LengthModifier LM; 424 OptionalAmount FieldWidth; 425 ConversionSpecifier CS; 426 OptionalAmount VectorNumElts; 427 428 /// Positional arguments, an IEEE extension: 429 /// IEEE Std 1003.1, 2004 Edition 430 /// http://www.opengroup.org/onlinepubs/009695399/functions/printf.html 431 bool UsesPositionalArg; 432 unsigned argIndex; 433 public: FormatSpecifier(bool isPrintf)434 FormatSpecifier(bool isPrintf) 435 : CS(isPrintf), VectorNumElts(false), 436 UsesPositionalArg(false), argIndex(0) {} 437 setLengthModifier(LengthModifier lm)438 void setLengthModifier(LengthModifier lm) { 439 LM = lm; 440 } 441 setUsesPositionalArg()442 void setUsesPositionalArg() { UsesPositionalArg = true; } 443 setArgIndex(unsigned i)444 void setArgIndex(unsigned i) { 445 argIndex = i; 446 } 447 getArgIndex()448 unsigned getArgIndex() const { 449 return argIndex; 450 } 451 getPositionalArgIndex()452 unsigned getPositionalArgIndex() const { 453 return argIndex + 1; 454 } 455 getLengthModifier()456 const LengthModifier &getLengthModifier() const { 457 return LM; 458 } 459 getFieldWidth()460 const OptionalAmount &getFieldWidth() const { 461 return FieldWidth; 462 } 463 setVectorNumElts(const OptionalAmount & Amt)464 void setVectorNumElts(const OptionalAmount &Amt) { 465 VectorNumElts = Amt; 466 } 467 getVectorNumElts()468 const OptionalAmount &getVectorNumElts() const { 469 return VectorNumElts; 470 } 471 setFieldWidth(const OptionalAmount & Amt)472 void setFieldWidth(const OptionalAmount &Amt) { 473 FieldWidth = Amt; 474 } 475 usesPositionalArg()476 bool usesPositionalArg() const { return UsesPositionalArg; } 477 478 bool hasValidLengthModifier(const TargetInfo &Target, 479 const LangOptions &LO) const; 480 481 bool hasStandardLengthModifier() const; 482 483 std::optional<LengthModifier> getCorrectedLengthModifier() const; 484 485 bool hasStandardConversionSpecifier(const LangOptions &LangOpt) const; 486 487 bool hasStandardLengthConversionCombination() const; 488 489 /// For a TypedefType QT, if it is a named integer type such as size_t, 490 /// assign the appropriate value to LM and return true. 491 static bool namedTypeToLengthModifier(QualType QT, LengthModifier &LM); 492 }; 493 494 } // end analyze_format_string namespace 495 496 //===----------------------------------------------------------------------===// 497 /// Pieces specific to fprintf format strings. 498 499 namespace analyze_printf { 500 501 class PrintfConversionSpecifier : 502 public analyze_format_string::ConversionSpecifier { 503 public: PrintfConversionSpecifier()504 PrintfConversionSpecifier() 505 : ConversionSpecifier(true, nullptr, InvalidSpecifier) {} 506 PrintfConversionSpecifier(const char * pos,Kind k)507 PrintfConversionSpecifier(const char *pos, Kind k) 508 : ConversionSpecifier(true, pos, k) {} 509 isObjCArg()510 bool isObjCArg() const { return kind >= ObjCBeg && kind <= ObjCEnd; } isDoubleArg()511 bool isDoubleArg() const { return kind >= DoubleArgBeg && 512 kind <= DoubleArgEnd; } 513 classof(const analyze_format_string::ConversionSpecifier * CS)514 static bool classof(const analyze_format_string::ConversionSpecifier *CS) { 515 return CS->isPrintfKind(); 516 } 517 }; 518 519 using analyze_format_string::ArgType; 520 using analyze_format_string::LengthModifier; 521 using analyze_format_string::OptionalAmount; 522 using analyze_format_string::OptionalFlag; 523 524 class PrintfSpecifier : public analyze_format_string::FormatSpecifier { 525 OptionalFlag HasThousandsGrouping; // ''', POSIX extension. 526 OptionalFlag IsLeftJustified; // '-' 527 OptionalFlag HasPlusPrefix; // '+' 528 OptionalFlag HasSpacePrefix; // ' ' 529 OptionalFlag HasAlternativeForm; // '#' 530 OptionalFlag HasLeadingZeroes; // '0' 531 OptionalFlag HasObjCTechnicalTerm; // '[tt]' 532 OptionalFlag IsPrivate; // '{private}' 533 OptionalFlag IsPublic; // '{public}' 534 OptionalFlag IsSensitive; // '{sensitive}' 535 OptionalAmount Precision; 536 StringRef MaskType; 537 538 ArgType getScalarArgType(ASTContext &Ctx, bool IsObjCLiteral) const; 539 540 public: PrintfSpecifier()541 PrintfSpecifier() 542 : FormatSpecifier(/* isPrintf = */ true), HasThousandsGrouping("'"), 543 IsLeftJustified("-"), HasPlusPrefix("+"), HasSpacePrefix(" "), 544 HasAlternativeForm("#"), HasLeadingZeroes("0"), 545 HasObjCTechnicalTerm("tt"), IsPrivate("private"), IsPublic("public"), 546 IsSensitive("sensitive") {} 547 548 static PrintfSpecifier Parse(const char *beg, const char *end); 549 550 // Methods for incrementally constructing the PrintfSpecifier. setConversionSpecifier(const PrintfConversionSpecifier & cs)551 void setConversionSpecifier(const PrintfConversionSpecifier &cs) { 552 CS = cs; 553 } setHasThousandsGrouping(const char * position)554 void setHasThousandsGrouping(const char *position) { 555 HasThousandsGrouping.setPosition(position); 556 } setIsLeftJustified(const char * position)557 void setIsLeftJustified(const char *position) { 558 IsLeftJustified.setPosition(position); 559 } setHasPlusPrefix(const char * position)560 void setHasPlusPrefix(const char *position) { 561 HasPlusPrefix.setPosition(position); 562 } setHasSpacePrefix(const char * position)563 void setHasSpacePrefix(const char *position) { 564 HasSpacePrefix.setPosition(position); 565 } setHasAlternativeForm(const char * position)566 void setHasAlternativeForm(const char *position) { 567 HasAlternativeForm.setPosition(position); 568 } setHasLeadingZeros(const char * position)569 void setHasLeadingZeros(const char *position) { 570 HasLeadingZeroes.setPosition(position); 571 } setHasObjCTechnicalTerm(const char * position)572 void setHasObjCTechnicalTerm(const char *position) { 573 HasObjCTechnicalTerm.setPosition(position); 574 } setIsPrivate(const char * position)575 void setIsPrivate(const char *position) { IsPrivate.setPosition(position); } setIsPublic(const char * position)576 void setIsPublic(const char *position) { IsPublic.setPosition(position); } setIsSensitive(const char * position)577 void setIsSensitive(const char *position) { 578 IsSensitive.setPosition(position); 579 } setUsesPositionalArg()580 void setUsesPositionalArg() { UsesPositionalArg = true; } 581 582 // Methods for querying the format specifier. 583 getConversionSpecifier()584 const PrintfConversionSpecifier &getConversionSpecifier() const { 585 return cast<PrintfConversionSpecifier>(CS); 586 } 587 setPrecision(const OptionalAmount & Amt)588 void setPrecision(const OptionalAmount &Amt) { 589 Precision = Amt; 590 Precision.setUsesDotPrefix(); 591 } 592 getPrecision()593 const OptionalAmount &getPrecision() const { 594 return Precision; 595 } 596 consumesDataArgument()597 bool consumesDataArgument() const { 598 return getConversionSpecifier().consumesDataArgument(); 599 } 600 601 /// Returns the builtin type that a data argument 602 /// paired with this format specifier should have. This method 603 /// will return null if the format specifier does not have 604 /// a matching data argument or the matching argument matches 605 /// more than one type. 606 ArgType getArgType(ASTContext &Ctx, bool IsObjCLiteral) const; 607 hasThousandsGrouping()608 const OptionalFlag &hasThousandsGrouping() const { 609 return HasThousandsGrouping; 610 } isLeftJustified()611 const OptionalFlag &isLeftJustified() const { return IsLeftJustified; } hasPlusPrefix()612 const OptionalFlag &hasPlusPrefix() const { return HasPlusPrefix; } hasAlternativeForm()613 const OptionalFlag &hasAlternativeForm() const { return HasAlternativeForm; } hasLeadingZeros()614 const OptionalFlag &hasLeadingZeros() const { return HasLeadingZeroes; } hasSpacePrefix()615 const OptionalFlag &hasSpacePrefix() const { return HasSpacePrefix; } hasObjCTechnicalTerm()616 const OptionalFlag &hasObjCTechnicalTerm() const { return HasObjCTechnicalTerm; } isPrivate()617 const OptionalFlag &isPrivate() const { return IsPrivate; } isPublic()618 const OptionalFlag &isPublic() const { return IsPublic; } isSensitive()619 const OptionalFlag &isSensitive() const { return IsSensitive; } usesPositionalArg()620 bool usesPositionalArg() const { return UsesPositionalArg; } 621 getMaskType()622 StringRef getMaskType() const { return MaskType; } setMaskType(StringRef S)623 void setMaskType(StringRef S) { MaskType = S; } 624 625 /// Changes the specifier and length according to a QualType, retaining any 626 /// flags or options. Returns true on success, or false when a conversion 627 /// was not successful. 628 bool fixType(QualType QT, const LangOptions &LangOpt, ASTContext &Ctx, 629 bool IsObjCLiteral); 630 631 void toString(raw_ostream &os) const; 632 633 // Validation methods - to check if any element results in undefined behavior 634 bool hasValidPlusPrefix() const; 635 bool hasValidAlternativeForm() const; 636 bool hasValidLeadingZeros() const; 637 bool hasValidSpacePrefix() const; 638 bool hasValidLeftJustified() const; 639 bool hasValidThousandsGroupingPrefix() const; 640 641 bool hasValidPrecision() const; 642 bool hasValidFieldWidth() const; 643 }; 644 } // end analyze_printf namespace 645 646 //===----------------------------------------------------------------------===// 647 /// Pieces specific to fscanf format strings. 648 649 namespace analyze_scanf { 650 651 class ScanfConversionSpecifier : 652 public analyze_format_string::ConversionSpecifier { 653 public: ScanfConversionSpecifier()654 ScanfConversionSpecifier() 655 : ConversionSpecifier(false, nullptr, InvalidSpecifier) {} 656 ScanfConversionSpecifier(const char * pos,Kind k)657 ScanfConversionSpecifier(const char *pos, Kind k) 658 : ConversionSpecifier(false, pos, k) {} 659 classof(const analyze_format_string::ConversionSpecifier * CS)660 static bool classof(const analyze_format_string::ConversionSpecifier *CS) { 661 return !CS->isPrintfKind(); 662 } 663 }; 664 665 using analyze_format_string::ArgType; 666 using analyze_format_string::LengthModifier; 667 using analyze_format_string::OptionalAmount; 668 using analyze_format_string::OptionalFlag; 669 670 class ScanfSpecifier : public analyze_format_string::FormatSpecifier { 671 OptionalFlag SuppressAssignment; // '*' 672 public: ScanfSpecifier()673 ScanfSpecifier() : 674 FormatSpecifier(/* isPrintf = */ false), 675 SuppressAssignment("*") {} 676 setSuppressAssignment(const char * position)677 void setSuppressAssignment(const char *position) { 678 SuppressAssignment.setPosition(position); 679 } 680 getSuppressAssignment()681 const OptionalFlag &getSuppressAssignment() const { 682 return SuppressAssignment; 683 } 684 setConversionSpecifier(const ScanfConversionSpecifier & cs)685 void setConversionSpecifier(const ScanfConversionSpecifier &cs) { 686 CS = cs; 687 } 688 getConversionSpecifier()689 const ScanfConversionSpecifier &getConversionSpecifier() const { 690 return cast<ScanfConversionSpecifier>(CS); 691 } 692 consumesDataArgument()693 bool consumesDataArgument() const { 694 return CS.consumesDataArgument() && !SuppressAssignment; 695 } 696 697 ArgType getArgType(ASTContext &Ctx) const; 698 699 bool fixType(QualType QT, QualType RawQT, const LangOptions &LangOpt, 700 ASTContext &Ctx); 701 702 void toString(raw_ostream &os) const; 703 704 static ScanfSpecifier Parse(const char *beg, const char *end); 705 }; 706 707 } // end analyze_scanf namespace 708 709 //===----------------------------------------------------------------------===// 710 // Parsing and processing of format strings (both fprintf and fscanf). 711 712 namespace analyze_format_string { 713 714 enum PositionContext { FieldWidthPos = 0, PrecisionPos = 1 }; 715 716 class FormatStringHandler { 717 public: FormatStringHandler()718 FormatStringHandler() {} 719 virtual ~FormatStringHandler(); 720 HandleNullChar(const char * nullCharacter)721 virtual void HandleNullChar(const char *nullCharacter) {} 722 HandlePosition(const char * startPos,unsigned posLen)723 virtual void HandlePosition(const char *startPos, unsigned posLen) {} 724 HandleInvalidPosition(const char * startPos,unsigned posLen,PositionContext p)725 virtual void HandleInvalidPosition(const char *startPos, unsigned posLen, 726 PositionContext p) {} 727 HandleZeroPosition(const char * startPos,unsigned posLen)728 virtual void HandleZeroPosition(const char *startPos, unsigned posLen) {} 729 HandleIncompleteSpecifier(const char * startSpecifier,unsigned specifierLen)730 virtual void HandleIncompleteSpecifier(const char *startSpecifier, 731 unsigned specifierLen) {} 732 HandleEmptyObjCModifierFlag(const char * startFlags,unsigned flagsLen)733 virtual void HandleEmptyObjCModifierFlag(const char *startFlags, 734 unsigned flagsLen) {} 735 HandleInvalidObjCModifierFlag(const char * startFlag,unsigned flagLen)736 virtual void HandleInvalidObjCModifierFlag(const char *startFlag, 737 unsigned flagLen) {} 738 HandleObjCFlagsWithNonObjCConversion(const char * flagsStart,const char * flagsEnd,const char * conversionPosition)739 virtual void HandleObjCFlagsWithNonObjCConversion(const char *flagsStart, 740 const char *flagsEnd, 741 const char *conversionPosition) {} 742 // Printf-specific handlers. 743 HandleInvalidPrintfConversionSpecifier(const analyze_printf::PrintfSpecifier & FS,const char * startSpecifier,unsigned specifierLen)744 virtual bool HandleInvalidPrintfConversionSpecifier( 745 const analyze_printf::PrintfSpecifier &FS, 746 const char *startSpecifier, 747 unsigned specifierLen) { 748 return true; 749 } 750 HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier & FS,const char * startSpecifier,unsigned specifierLen,const TargetInfo & Target)751 virtual bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS, 752 const char *startSpecifier, 753 unsigned specifierLen, 754 const TargetInfo &Target) { 755 return true; 756 } 757 758 /// Handle mask types whose sizes are not between one and eight bytes. handleInvalidMaskType(StringRef MaskType)759 virtual void handleInvalidMaskType(StringRef MaskType) {} 760 761 // Scanf-specific handlers. 762 HandleInvalidScanfConversionSpecifier(const analyze_scanf::ScanfSpecifier & FS,const char * startSpecifier,unsigned specifierLen)763 virtual bool HandleInvalidScanfConversionSpecifier( 764 const analyze_scanf::ScanfSpecifier &FS, 765 const char *startSpecifier, 766 unsigned specifierLen) { 767 return true; 768 } 769 HandleScanfSpecifier(const analyze_scanf::ScanfSpecifier & FS,const char * startSpecifier,unsigned specifierLen)770 virtual bool HandleScanfSpecifier(const analyze_scanf::ScanfSpecifier &FS, 771 const char *startSpecifier, 772 unsigned specifierLen) { 773 return true; 774 } 775 HandleIncompleteScanList(const char * start,const char * end)776 virtual void HandleIncompleteScanList(const char *start, const char *end) {} 777 }; 778 779 bool ParsePrintfString(FormatStringHandler &H, 780 const char *beg, const char *end, const LangOptions &LO, 781 const TargetInfo &Target, bool isFreeBSDKPrintf); 782 783 bool ParseFormatStringHasSArg(const char *beg, const char *end, 784 const LangOptions &LO, const TargetInfo &Target); 785 786 bool ParseScanfString(FormatStringHandler &H, 787 const char *beg, const char *end, const LangOptions &LO, 788 const TargetInfo &Target); 789 790 /// Return true if the given string has at least one formatting specifier. 791 bool parseFormatStringHasFormattingSpecifiers(const char *Begin, 792 const char *End, 793 const LangOptions &LO, 794 const TargetInfo &Target); 795 796 } // end analyze_format_string namespace 797 } // end clang namespace 798 #endif 799