clang/lib/AST/FormatString.cpp

   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.
  29 FormatStringHandler::~FormatStringHandler() {}
  30
  31 //===----------------------------------------------------------------------===//
  32 // Functions for parsing format strings components in both printf and
  33 // scanf format strings.
  34 //===----------------------------------------------------------------------===//
  35
  36 OptionalAmount
  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
  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
  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
 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
 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
 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
 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
 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
 324 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'. 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       argTy = C.getCanonicalType(argTy).getUnqualifiedType();
 407
 408       if (T == argTy)
 409         return Match;
 410       if (const auto *BT = argTy->getAs<BuiltinType>()) {
 411         // Check if the only difference between them is signed vs unsigned
 412         // if true, we consider they are compatible.
 413         switch (BT->getKind()) {
 414           default:
 415             break;
 416           case BuiltinType::Bool:
 417             if (Ptr && (T == C.UnsignedCharTy || T == C.SignedCharTy))
 418               return NoMatch;
 419             [[fallthrough]];
 420           case BuiltinType::Char_S:
 421           case BuiltinType::SChar:
 422           case BuiltinType::Char_U:
 423           case BuiltinType::UChar:
 424             if (T == C.UnsignedShortTy || T == C.ShortTy)
 425               return NoMatchTypeConfusion;
 426             if (T == C.UnsignedCharTy || T == C.SignedCharTy)
 427               return Match;
 428             break;
 429           case BuiltinType::Short:
 430             if (T == C.UnsignedShortTy)
 431               return Match;
 432             break;
 433           case BuiltinType::UShort:
 434             if (T == C.ShortTy)
 435               return Match;
 436             break;
 437           case BuiltinType::Int:
 438             if (T == C.UnsignedIntTy)
 439               return Match;
 440             break;
 441           case BuiltinType::UInt:
 442             if (T == C.IntTy)
 443               return Match;
 444             break;
 445           case BuiltinType::Long:
 446             if (T == C.UnsignedLongTy)
 447               return Match;
 448             break;
 449           case BuiltinType::ULong:
 450             if (T == C.LongTy)
 451               return Match;
 452             break;
 453           case BuiltinType::LongLong:
 454             if (T == C.UnsignedLongLongTy)
 455               return Match;
 456             break;
 457           case BuiltinType::ULongLong:
 458             if (T == C.LongLongTy)
 459               return Match;
 460             break;
 461           }
 462           // "Partially matched" because of promotions?
 463           if (!Ptr) {
 464             switch (BT->getKind()) {
 465             default:
 466               break;
 467             case BuiltinType::Bool:
 468               if (T == C.IntTy || T == C.UnsignedIntTy)
 469                 return MatchPromotion;
 470               break;
 471             case BuiltinType::Int:
 472             case BuiltinType::UInt:
 473               if (T == C.SignedCharTy || T == C.UnsignedCharTy ||
 474                   T == C.ShortTy || T == C.UnsignedShortTy || T == C.WCharTy ||
 475                   T == C.WideCharTy)
 476                 return MatchPromotion;
 477               break;
 478             case BuiltinType::Char_U:
 479               if (T == C.UnsignedIntTy)
 480                 return MatchPromotion;
 481               if (T == C.UnsignedShortTy)
 482                 return NoMatchPromotionTypeConfusion;
 483               break;
 484             case BuiltinType::Char_S:
 485               if (T == C.IntTy)
 486                 return MatchPromotion;
 487               if (T == C.ShortTy)
 488                 return NoMatchPromotionTypeConfusion;
 489               break;
 490             case BuiltinType::Half:
 491             case BuiltinType::Float16:
 492             case BuiltinType::Float:
 493               if (T == C.DoubleTy)
 494                 return MatchPromotion;
 495               break;
 496             case BuiltinType::Short:
 497             case BuiltinType::UShort:
 498               if (T == C.SignedCharTy || T == C.UnsignedCharTy)
 499                 return NoMatchPromotionTypeConfusion;
 500               break;
 501             case BuiltinType::WChar_U:
 502             case BuiltinType::WChar_S:
 503               if (T != C.WCharTy && T != C.WideCharTy)
 504                 return NoMatchPromotionTypeConfusion;
 505             }
 506           }
 507       }
 508       return NoMatch;
 509     }
 510
 511     case CStrTy: {
 512       const PointerType *PT = argTy->getAs<PointerType>();
 513       if (!PT)
 514         return NoMatch;
 515       QualType pointeeTy = PT->getPointeeType();
 516       if (const BuiltinType *BT = pointeeTy->getAs<BuiltinType>())
 517         switch (BT->getKind()) {
 518           case BuiltinType::Char_U:
 519           case BuiltinType::UChar:
 520           case BuiltinType::Char_S:
 521           case BuiltinType::SChar:
 522             return Match;
 523           default:
 524             break;
 525         }
 526
 527       return NoMatch;
 528     }
 529
 530     case WCStrTy: {
 531       const PointerType *PT = argTy->getAs<PointerType>();
 532       if (!PT)
 533         return NoMatch;
 534       QualType pointeeTy =
 535         C.getCanonicalType(PT->getPointeeType()).getUnqualifiedType();
 536       return pointeeTy == C.getWideCharType() ? Match : NoMatch;
 537     }
 538
 539     case WIntTy: {
 540       QualType WInt = C.getCanonicalType(C.getWIntType()).getUnqualifiedType();
 541
 542       if (C.getCanonicalType(argTy).getUnqualifiedType() == WInt)
 543         return Match;
 544
 545       QualType PromoArg = C.isPromotableIntegerType(argTy)
 546                               ? C.getPromotedIntegerType(argTy)
 547                               : argTy;
 548       PromoArg = C.getCanonicalType(PromoArg).getUnqualifiedType();
 549
 550       // If the promoted argument is the corresponding signed type of the
 551       // wint_t type, then it should match.
 552       if (PromoArg->hasSignedIntegerRepresentation() &&
 553           C.getCorrespondingUnsignedType(PromoArg) == WInt)
 554         return Match;
 555
 556       return WInt == PromoArg ? Match : NoMatch;
 557     }
 558
 559     case CPointerTy:
 560       if (argTy->isVoidPointerType()) {
 561         return Match;
 562       } if (argTy->isPointerType() || argTy->isObjCObjectPointerType() ||
 563             argTy->isBlockPointerType() || argTy->isNullPtrType()) {
 564         return NoMatchPedantic;
 565       } else {
 566         return NoMatch;
 567       }
 568
 569     case ObjCPointerTy: {
 570       if (argTy->getAs<ObjCObjectPointerType>() ||
 571           argTy->getAs<BlockPointerType>())
 572         return Match;
 573
 574       // Handle implicit toll-free bridging.
 575       if (const PointerType *PT = argTy->getAs<PointerType>()) {
 576         // Things such as CFTypeRef are really just opaque pointers
 577         // to C structs representing CF types that can often be bridged
 578         // to Objective-C objects.  Since the compiler doesn't know which
 579         // structs can be toll-free bridged, we just accept them all.
 580         QualType pointee = PT->getPointeeType();
 581         if (pointee->getAsStructureType() || pointee->isVoidType())
 582           return Match;
 583       }
 584       return NoMatch;
 585     }
 586   }
 587
 588   llvm_unreachable("Invalid ArgType Kind!");
 589 }
 590
 591 ArgType ArgType::makeVectorType(ASTContext &C, unsigned NumElts) const {
 592   // Check for valid vector element types.
 593   if (T.isNull())
 594     return ArgType::Invalid();
 595
 596   QualType Vec = C.getExtVectorType(T, NumElts);
 597   return ArgType(Vec, Name);
 598 }
 599
 600 QualType ArgType::getRepresentativeType(ASTContext &C) const {
 601   QualType Res;
 602   switch (K) {
 603     case InvalidTy:
 604       llvm_unreachable("No representative type for Invalid ArgType");
 605     case UnknownTy:
 606       llvm_unreachable("No representative type for Unknown ArgType");
 607     case AnyCharTy:
 608       Res = C.CharTy;
 609       break;
 610     case SpecificTy:
 611       Res = T;
 612       break;
 613     case CStrTy:
 614       Res = C.getPointerType(C.CharTy);
 615       break;
 616     case WCStrTy:
 617       Res = C.getPointerType(C.getWideCharType());
 618       break;
 619     case ObjCPointerTy:
 620       Res = C.ObjCBuiltinIdTy;
 621       break;
 622     case CPointerTy:
 623       Res = C.VoidPtrTy;
 624       break;
 625     case WIntTy: {
 626       Res = C.getWIntType();
 627       break;
 628     }
 629   }
 630
 631   if (Ptr)
 632     Res = C.getPointerType(Res);
 633   return Res;
 634 }
 635
 636 std::string ArgType::getRepresentativeTypeName(ASTContext &C) const {
 637   std::string S = getRepresentativeType(C).getAsString(C.getPrintingPolicy());
 638
 639   std::string Alias;
 640   if (Name) {
 641     // Use a specific name for this type, e.g. "size_t".
 642     Alias = Name;
 643     if (Ptr) {
 644       // If ArgType is actually a pointer to T, append an asterisk.
 645       Alias += (Alias[Alias.size()-1] == '*') ? "*" : " *";
 646     }
 647     // If Alias is the same as the underlying type, e.g. wchar_t, then drop it.
 648     if (S == Alias)
 649       Alias.clear();
 650   }
 651
 652   if (!Alias.empty())
 653     return std::string("'") + Alias + "' (aka '" + S + "')";
 654   return std::string("'") + S + "'";
 655 }
 656
 657
 658 //===----------------------------------------------------------------------===//
 659 // Methods on OptionalAmount.
 660 //===----------------------------------------------------------------------===//
 661
 662 ArgType
 663 analyze_format_string::OptionalAmount::getArgType(ASTContext &Ctx) const {
 664   return Ctx.IntTy;
 665 }
 666
 667 //===----------------------------------------------------------------------===//
 668 // Methods on LengthModifier.
 669 //===----------------------------------------------------------------------===//
 670
 671 const char *
 672 analyze_format_string::LengthModifier::toString() const {
 673   switch (kind) {
 674   case AsChar:
 675     return "hh";
 676   case AsShort:
 677     return "h";
 678   case AsShortLong:
 679     return "hl";
 680   case AsLong: // or AsWideChar
 681     return "l";
 682   case AsLongLong:
 683     return "ll";
 684   case AsQuad:
 685     return "q";
 686   case AsIntMax:
 687     return "j";
 688   case AsSizeT:
 689     return "z";
 690   case AsPtrDiff:
 691     return "t";
 692   case AsInt32:
 693     return "I32";
 694   case AsInt3264:
 695     return "I";
 696   case AsInt64:
 697     return "I64";
 698   case AsLongDouble:
 699     return "L";
 700   case AsAllocate:
 701     return "a";
 702   case AsMAllocate:
 703     return "m";
 704   case AsWide:
 705     return "w";
 706   case None:
 707     return "";
 708   }
 709   return nullptr;
 710 }
 711
 712 //===----------------------------------------------------------------------===//
 713 // Methods on ConversionSpecifier.
 714 //===----------------------------------------------------------------------===//
 715
 716 const char *ConversionSpecifier::toString() const {
 717   switch (kind) {
 718   case bArg: return "b";
 719   case BArg: return "B";
 720   case dArg: return "d";
 721   case DArg: return "D";
 722   case iArg: return "i";
 723   case oArg: return "o";
 724   case OArg: return "O";
 725   case uArg: return "u";
 726   case UArg: return "U";
 727   case xArg: return "x";
 728   case XArg: return "X";
 729   case fArg: return "f";
 730   case FArg: return "F";
 731   case eArg: return "e";
 732   case EArg: return "E";
 733   case gArg: return "g";
 734   case GArg: return "G";
 735   case aArg: return "a";
 736   case AArg: return "A";
 737   case cArg: return "c";
 738   case sArg: return "s";
 739   case pArg: return "p";
 740   case PArg:
 741     return "P";
 742   case nArg: return "n";
 743   case PercentArg:  return "%";
 744   case ScanListArg: return "[";
 745   case InvalidSpecifier: return nullptr;
 746
 747   // POSIX unicode extensions.
 748   case CArg: return "C";
 749   case SArg: return "S";
 750
 751   // Objective-C specific specifiers.
 752   case ObjCObjArg: return "@";
 753
 754   // FreeBSD kernel specific specifiers.
 755   case FreeBSDbArg: return "b";
 756   case FreeBSDDArg: return "D";
 757   case FreeBSDrArg: return "r";
 758   case FreeBSDyArg: return "y";
 759
 760   // GlibC specific specifiers.
 761   case PrintErrno: return "m";
 762
 763   // MS specific specifiers.
 764   case ZArg: return "Z";
 765   }
 766   return nullptr;
 767 }
 768
 769 std::optional<ConversionSpecifier>
 770 ConversionSpecifier::getStandardSpecifier() const {
 771   ConversionSpecifier::Kind NewKind;
 772
 773   switch (getKind()) {
 774   default:
 775     return std::nullopt;
 776   case DArg:
 777     NewKind = dArg;
 778     break;
 779   case UArg:
 780     NewKind = uArg;
 781     break;
 782   case OArg:
 783     NewKind = oArg;
 784     break;
 785   }
 786
 787   ConversionSpecifier FixedCS(*this);
 788   FixedCS.setKind(NewKind);
 789   return FixedCS;
 790 }
 791
 792 //===----------------------------------------------------------------------===//
 793 // Methods on OptionalAmount.
 794 //===----------------------------------------------------------------------===//
 795
 796 void OptionalAmount::toString(raw_ostream &os) const {
 797   switch (hs) {
 798   case Invalid:
 799   case NotSpecified:
 800     return;
 801   case Arg:
 802     if (UsesDotPrefix)
 803         os << ".";
 804     if (usesPositionalArg())
 805       os << "*" << getPositionalArgIndex() << "$";
 806     else
 807       os << "*";
 808     break;
 809   case Constant:
 810     if (UsesDotPrefix)
 811         os << ".";
 812     os << amt;
 813     break;
 814   }
 815 }
 816
 817 bool FormatSpecifier::hasValidLengthModifier(const TargetInfo &Target,
 818                                              const LangOptions &LO) const {
 819   switch (LM.getKind()) {
 820     case LengthModifier::None:
 821       return true;
 822
 823     // Handle most integer flags
 824     case LengthModifier::AsShort:
 825       // Length modifier only applies to FP vectors.
 826       if (LO.OpenCL && CS.isDoubleArg())
 827         return !VectorNumElts.isInvalid();
 828
 829       if (Target.getTriple().isOSMSVCRT()) {
 830         switch (CS.getKind()) {
 831           case ConversionSpecifier::cArg:
 832           case ConversionSpecifier::CArg:
 833           case ConversionSpecifier::sArg:
 834           case ConversionSpecifier::SArg:
 835           case ConversionSpecifier::ZArg:
 836             return true;
 837           default:
 838             break;
 839         }
 840       }
 841       [[fallthrough]];
 842     case LengthModifier::AsChar:
 843     case LengthModifier::AsLongLong:
 844     case LengthModifier::AsQuad:
 845     case LengthModifier::AsIntMax:
 846     case LengthModifier::AsSizeT:
 847     case LengthModifier::AsPtrDiff:
 848       switch (CS.getKind()) {
 849         case ConversionSpecifier::bArg:
 850         case ConversionSpecifier::BArg:
 851         case ConversionSpecifier::dArg:
 852         case ConversionSpecifier::DArg:
 853         case ConversionSpecifier::iArg:
 854         case ConversionSpecifier::oArg:
 855         case ConversionSpecifier::OArg:
 856         case ConversionSpecifier::uArg:
 857         case ConversionSpecifier::UArg:
 858         case ConversionSpecifier::xArg:
 859         case ConversionSpecifier::XArg:
 860         case ConversionSpecifier::nArg:
 861           return true;
 862         case ConversionSpecifier::FreeBSDrArg:
 863         case ConversionSpecifier::FreeBSDyArg:
 864           return Target.getTriple().isOSFreeBSD() || Target.getTriple().isPS();
 865         default:
 866           return false;
 867       }
 868
 869     case LengthModifier::AsShortLong:
 870       return LO.OpenCL && !VectorNumElts.isInvalid();
 871
 872     // Handle 'l' flag
 873     case LengthModifier::AsLong: // or AsWideChar
 874       if (CS.isDoubleArg()) {
 875         // Invalid for OpenCL FP scalars.
 876         if (LO.OpenCL && VectorNumElts.isInvalid())
 877           return false;
 878         return true;
 879       }
 880
 881       switch (CS.getKind()) {
 882         case ConversionSpecifier::bArg:
 883         case ConversionSpecifier::BArg:
 884         case ConversionSpecifier::dArg:
 885         case ConversionSpecifier::DArg:
 886         case ConversionSpecifier::iArg:
 887         case ConversionSpecifier::oArg:
 888         case ConversionSpecifier::OArg:
 889         case ConversionSpecifier::uArg:
 890         case ConversionSpecifier::UArg:
 891         case ConversionSpecifier::xArg:
 892         case ConversionSpecifier::XArg:
 893         case ConversionSpecifier::nArg:
 894         case ConversionSpecifier::cArg:
 895         case ConversionSpecifier::sArg:
 896         case ConversionSpecifier::ScanListArg:
 897         case ConversionSpecifier::ZArg:
 898           return true;
 899         case ConversionSpecifier::FreeBSDrArg:
 900         case ConversionSpecifier::FreeBSDyArg:
 901           return Target.getTriple().isOSFreeBSD() || Target.getTriple().isPS();
 902         default:
 903           return false;
 904       }
 905
 906     case LengthModifier::AsLongDouble:
 907       switch (CS.getKind()) {
 908         case ConversionSpecifier::aArg:
 909         case ConversionSpecifier::AArg:
 910         case ConversionSpecifier::fArg:
 911         case ConversionSpecifier::FArg:
 912         case ConversionSpecifier::eArg:
 913         case ConversionSpecifier::EArg:
 914         case ConversionSpecifier::gArg:
 915         case ConversionSpecifier::GArg:
 916           return true;
 917         // GNU libc extension.
 918         case ConversionSpecifier::dArg:
 919         case ConversionSpecifier::iArg:
 920         case ConversionSpecifier::oArg:
 921         case ConversionSpecifier::uArg:
 922         case ConversionSpecifier::xArg:
 923         case ConversionSpecifier::XArg:
 924           return !Target.getTriple().isOSDarwin() &&
 925                  !Target.getTriple().isOSWindows();
 926         default:
 927           return false;
 928       }
 929
 930     case LengthModifier::AsAllocate:
 931       switch (CS.getKind()) {
 932         case ConversionSpecifier::sArg:
 933         case ConversionSpecifier::SArg:
 934         case ConversionSpecifier::ScanListArg:
 935           return true;
 936         default:
 937           return false;
 938       }
 939
 940     case LengthModifier::AsMAllocate:
 941       switch (CS.getKind()) {
 942         case ConversionSpecifier::cArg:
 943         case ConversionSpecifier::CArg:
 944         case ConversionSpecifier::sArg:
 945         case ConversionSpecifier::SArg:
 946         case ConversionSpecifier::ScanListArg:
 947           return true;
 948         default:
 949           return false;
 950       }
 951     case LengthModifier::AsInt32:
 952     case LengthModifier::AsInt3264:
 953     case LengthModifier::AsInt64:
 954       switch (CS.getKind()) {
 955         case ConversionSpecifier::dArg:
 956         case ConversionSpecifier::iArg:
 957         case ConversionSpecifier::oArg:
 958         case ConversionSpecifier::uArg:
 959         case ConversionSpecifier::xArg:
 960         case ConversionSpecifier::XArg:
 961           return Target.getTriple().isOSMSVCRT();
 962         default:
 963           return false;
 964       }
 965     case LengthModifier::AsWide:
 966       switch (CS.getKind()) {
 967         case ConversionSpecifier::cArg:
 968         case ConversionSpecifier::CArg:
 969         case ConversionSpecifier::sArg:
 970         case ConversionSpecifier::SArg:
 971         case ConversionSpecifier::ZArg:
 972           return Target.getTriple().isOSMSVCRT();
 973         default:
 974           return false;
 975       }
 976   }
 977   llvm_unreachable("Invalid LengthModifier Kind!");
 978 }
 979
 980 bool FormatSpecifier::hasStandardLengthModifier() const {
 981   switch (LM.getKind()) {
 982     case LengthModifier::None:
 983     case LengthModifier::AsChar:
 984     case LengthModifier::AsShort:
 985     case LengthModifier::AsLong:
 986     case LengthModifier::AsLongLong:
 987     case LengthModifier::AsIntMax:
 988     case LengthModifier::AsSizeT:
 989     case LengthModifier::AsPtrDiff:
 990     case LengthModifier::AsLongDouble:
 991       return true;
 992     case LengthModifier::AsAllocate:
 993     case LengthModifier::AsMAllocate:
 994     case LengthModifier::AsQuad:
 995     case LengthModifier::AsInt32:
 996     case LengthModifier::AsInt3264:
 997     case LengthModifier::AsInt64:
 998     case LengthModifier::AsWide:
 999     case LengthModifier::AsShortLong: // ???
1000       return false;
1001   }
1002   llvm_unreachable("Invalid LengthModifier Kind!");
1003 }
1004
1005 bool FormatSpecifier::hasStandardConversionSpecifier(
1006     const LangOptions &LangOpt) const {
1007   switch (CS.getKind()) {
1008     case ConversionSpecifier::bArg:
1009     case ConversionSpecifier::BArg:
1010     case ConversionSpecifier::cArg:
1011     case ConversionSpecifier::dArg:
1012     case ConversionSpecifier::iArg:
1013     case ConversionSpecifier::oArg:
1014     case ConversionSpecifier::uArg:
1015     case ConversionSpecifier::xArg:
1016     case ConversionSpecifier::XArg:
1017     case ConversionSpecifier::fArg:
1018     case ConversionSpecifier::FArg:
1019     case ConversionSpecifier::eArg:
1020     case ConversionSpecifier::EArg:
1021     case ConversionSpecifier::gArg:
1022     case ConversionSpecifier::GArg:
1023     case ConversionSpecifier::aArg:
1024     case ConversionSpecifier::AArg:
1025     case ConversionSpecifier::sArg:
1026     case ConversionSpecifier::pArg:
1027     case ConversionSpecifier::nArg:
1028     case ConversionSpecifier::ObjCObjArg:
1029     case ConversionSpecifier::ScanListArg:
1030     case ConversionSpecifier::PercentArg:
1031     case ConversionSpecifier::PArg:
1032       return true;
1033     case ConversionSpecifier::CArg:
1034     case ConversionSpecifier::SArg:
1035       return LangOpt.ObjC;
1036     case ConversionSpecifier::InvalidSpecifier:
1037     case ConversionSpecifier::FreeBSDbArg:
1038     case ConversionSpecifier::FreeBSDDArg:
1039     case ConversionSpecifier::FreeBSDrArg:
1040     case ConversionSpecifier::FreeBSDyArg:
1041     case ConversionSpecifier::PrintErrno:
1042     case ConversionSpecifier::DArg:
1043     case ConversionSpecifier::OArg:
1044     case ConversionSpecifier::UArg:
1045     case ConversionSpecifier::ZArg:
1046       return false;
1047   }
1048   llvm_unreachable("Invalid ConversionSpecifier Kind!");
1049 }
1050
1051 bool FormatSpecifier::hasStandardLengthConversionCombination() const {
1052   if (LM.getKind() == LengthModifier::AsLongDouble) {
1053     switch(CS.getKind()) {
1054         case ConversionSpecifier::dArg:
1055         case ConversionSpecifier::iArg:
1056         case ConversionSpecifier::oArg:
1057         case ConversionSpecifier::uArg:
1058         case ConversionSpecifier::xArg:
1059         case ConversionSpecifier::XArg:
1060           return false;
1061         default:
1062           return true;
1063     }
1064   }
1065   return true;
1066 }
1067
1068 std::optional<LengthModifier>
1069 FormatSpecifier::getCorrectedLengthModifier() const {
1070   if (CS.isAnyIntArg() || CS.getKind() == ConversionSpecifier::nArg) {
1071     if (LM.getKind() == LengthModifier::AsLongDouble ||
1072         LM.getKind() == LengthModifier::AsQuad) {
1073       LengthModifier FixedLM(LM);
1074       FixedLM.setKind(LengthModifier::AsLongLong);
1075       return FixedLM;
1076     }
1077   }
1078
1079   return std::nullopt;
1080 }
1081
1082 bool FormatSpecifier::namedTypeToLengthModifier(QualType QT,
1083                                                 LengthModifier &LM) {
1084   for (/**/; const auto *TT = QT->getAs<TypedefType>();
1085        QT = TT->getDecl()->getUnderlyingType()) {
1086     const TypedefNameDecl *Typedef = TT->getDecl();
1087     const IdentifierInfo *Identifier = Typedef->getIdentifier();
1088     if (Identifier->getName() == "size_t") {
1089       LM.setKind(LengthModifier::AsSizeT);
1090       return true;
1091     } else if (Identifier->getName() == "ssize_t") {
1092       // Not C99, but common in Unix.
1093       LM.setKind(LengthModifier::AsSizeT);
1094       return true;
1095     } else if (Identifier->getName() == "intmax_t") {
1096       LM.setKind(LengthModifier::AsIntMax);
1097       return true;
1098     } else if (Identifier->getName() == "uintmax_t") {
1099       LM.setKind(LengthModifier::AsIntMax);
1100       return true;
1101     } else if (Identifier->getName() == "ptrdiff_t") {
1102       LM.setKind(LengthModifier::AsPtrDiff);
1103       return true;
1104     }
1105   }
1106   return false;
1107 }