PrintfFormatString.cpp revision 153acdb7310b20a72e608cbb10946621f161eb70
1//== PrintfFormatString.cpp - Analysis of printf format strings --*- C++ -*-==// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// Handling of format string in printf and friends. The structure of format 11// strings for fprintf() are described in C99 7.19.6.1. 12// 13//===----------------------------------------------------------------------===// 14 15#include "clang/Analysis/Analyses/FormatString.h" 16#include "FormatStringParsing.h" 17 18using clang::analyze_format_string::ArgTypeResult; 19using clang::analyze_format_string::FormatStringHandler; 20using clang::analyze_format_string::LengthModifier; 21using clang::analyze_format_string::OptionalAmount; 22using clang::analyze_format_string::ConversionSpecifier; 23using clang::analyze_printf::PrintfSpecifier; 24 25using namespace clang; 26 27typedef clang::analyze_format_string::SpecifierResult<PrintfSpecifier> 28 PrintfSpecifierResult; 29 30//===----------------------------------------------------------------------===// 31// Methods for parsing format strings. 32//===----------------------------------------------------------------------===// 33 34using analyze_format_string::ParseNonPositionAmount; 35 36static bool ParsePrecision(FormatStringHandler &H, PrintfSpecifier &FS, 37 const char *Start, const char *&Beg, const char *E, 38 unsigned *argIndex) { 39 if (argIndex) { 40 FS.setPrecision(ParseNonPositionAmount(Beg, E, *argIndex)); 41 } else { 42 const OptionalAmount Amt = ParsePositionAmount(H, Start, Beg, E, 43 analyze_format_string::PrecisionPos); 44 if (Amt.isInvalid()) 45 return true; 46 FS.setPrecision(Amt); 47 } 48 return false; 49} 50 51static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H, 52 const char *&Beg, 53 const char *E, 54 unsigned &argIndex, 55 const LangOptions &LO) { 56 57 using namespace clang::analyze_format_string; 58 using namespace clang::analyze_printf; 59 60 const char *I = Beg; 61 const char *Start = 0; 62 UpdateOnReturn <const char*> UpdateBeg(Beg, I); 63 64 // Look for a '%' character that indicates the start of a format specifier. 65 for ( ; I != E ; ++I) { 66 char c = *I; 67 if (c == '\0') { 68 // Detect spurious null characters, which are likely errors. 69 H.HandleNullChar(I); 70 return true; 71 } 72 if (c == '%') { 73 Start = I++; // Record the start of the format specifier. 74 break; 75 } 76 } 77 78 // No format specifier found? 79 if (!Start) 80 return false; 81 82 if (I == E) { 83 // No more characters left? 84 H.HandleIncompleteSpecifier(Start, E - Start); 85 return true; 86 } 87 88 PrintfSpecifier FS; 89 if (ParseArgPosition(H, FS, Start, I, E)) 90 return true; 91 92 if (I == E) { 93 // No more characters left? 94 H.HandleIncompleteSpecifier(Start, E - Start); 95 return true; 96 } 97 98 // Look for flags (if any). 99 bool hasMore = true; 100 for ( ; I != E; ++I) { 101 switch (*I) { 102 default: hasMore = false; break; 103 case '\'': 104 // FIXME: POSIX specific. Always accept? 105 FS.setHasThousandsGrouping(I); 106 break; 107 case '-': FS.setIsLeftJustified(I); break; 108 case '+': FS.setHasPlusPrefix(I); break; 109 case ' ': FS.setHasSpacePrefix(I); break; 110 case '#': FS.setHasAlternativeForm(I); break; 111 case '0': FS.setHasLeadingZeros(I); break; 112 } 113 if (!hasMore) 114 break; 115 } 116 117 if (I == E) { 118 // No more characters left? 119 H.HandleIncompleteSpecifier(Start, E - Start); 120 return true; 121 } 122 123 // Look for the field width (if any). 124 if (ParseFieldWidth(H, FS, Start, I, E, 125 FS.usesPositionalArg() ? 0 : &argIndex)) 126 return true; 127 128 if (I == E) { 129 // No more characters left? 130 H.HandleIncompleteSpecifier(Start, E - Start); 131 return true; 132 } 133 134 // Look for the precision (if any). 135 if (*I == '.') { 136 ++I; 137 if (I == E) { 138 H.HandleIncompleteSpecifier(Start, E - Start); 139 return true; 140 } 141 142 if (ParsePrecision(H, FS, Start, I, E, 143 FS.usesPositionalArg() ? 0 : &argIndex)) 144 return true; 145 146 if (I == E) { 147 // No more characters left? 148 H.HandleIncompleteSpecifier(Start, E - Start); 149 return true; 150 } 151 } 152 153 // Look for the length modifier. 154 if (ParseLengthModifier(FS, I, E, LO) && I == E) { 155 // No more characters left? 156 H.HandleIncompleteSpecifier(Start, E - Start); 157 return true; 158 } 159 160 if (*I == '\0') { 161 // Detect spurious null characters, which are likely errors. 162 H.HandleNullChar(I); 163 return true; 164 } 165 166 // Finally, look for the conversion specifier. 167 const char *conversionPosition = I++; 168 ConversionSpecifier::Kind k = ConversionSpecifier::InvalidSpecifier; 169 switch (*conversionPosition) { 170 default: 171 break; 172 // C99: 7.19.6.1 (section 8). 173 case '%': k = ConversionSpecifier::PercentArg; break; 174 case 'A': k = ConversionSpecifier::AArg; break; 175 case 'E': k = ConversionSpecifier::EArg; break; 176 case 'F': k = ConversionSpecifier::FArg; break; 177 case 'G': k = ConversionSpecifier::GArg; break; 178 case 'X': k = ConversionSpecifier::XArg; break; 179 case 'a': k = ConversionSpecifier::aArg; break; 180 case 'c': k = ConversionSpecifier::cArg; break; 181 case 'd': k = ConversionSpecifier::dArg; break; 182 case 'e': k = ConversionSpecifier::eArg; break; 183 case 'f': k = ConversionSpecifier::fArg; break; 184 case 'g': k = ConversionSpecifier::gArg; break; 185 case 'i': k = ConversionSpecifier::iArg; break; 186 case 'n': k = ConversionSpecifier::nArg; break; 187 case 'o': k = ConversionSpecifier::oArg; break; 188 case 'p': k = ConversionSpecifier::pArg; break; 189 case 's': k = ConversionSpecifier::sArg; break; 190 case 'u': k = ConversionSpecifier::uArg; break; 191 case 'x': k = ConversionSpecifier::xArg; break; 192 // POSIX specific. 193 case 'C': k = ConversionSpecifier::CArg; break; 194 case 'S': k = ConversionSpecifier::SArg; break; 195 // Objective-C. 196 case '@': k = ConversionSpecifier::ObjCObjArg; break; 197 // Glibc specific. 198 case 'm': k = ConversionSpecifier::PrintErrno; break; 199 } 200 PrintfConversionSpecifier CS(conversionPosition, k); 201 FS.setConversionSpecifier(CS); 202 if (CS.consumesDataArgument() && !FS.usesPositionalArg()) 203 FS.setArgIndex(argIndex++); 204 205 if (k == ConversionSpecifier::InvalidSpecifier) { 206 // Assume the conversion takes one argument. 207 return !H.HandleInvalidPrintfConversionSpecifier(FS, Start, I - Start); 208 } 209 return PrintfSpecifierResult(Start, FS); 210} 211 212bool clang::analyze_format_string::ParsePrintfString(FormatStringHandler &H, 213 const char *I, 214 const char *E, 215 const LangOptions &LO) { 216 217 unsigned argIndex = 0; 218 219 // Keep looking for a format specifier until we have exhausted the string. 220 while (I != E) { 221 const PrintfSpecifierResult &FSR = ParsePrintfSpecifier(H, I, E, argIndex, 222 LO); 223 // Did a fail-stop error of any kind occur when parsing the specifier? 224 // If so, don't do any more processing. 225 if (FSR.shouldStop()) 226 return true;; 227 // Did we exhaust the string or encounter an error that 228 // we can recover from? 229 if (!FSR.hasValue()) 230 continue; 231 // We have a format specifier. Pass it to the callback. 232 if (!H.HandlePrintfSpecifier(FSR.getValue(), FSR.getStart(), 233 I - FSR.getStart())) 234 return true; 235 } 236 assert(I == E && "Format string not exhausted"); 237 return false; 238} 239 240//===----------------------------------------------------------------------===// 241// Methods on PrintfSpecifier. 242//===----------------------------------------------------------------------===// 243 244ArgTypeResult PrintfSpecifier::getArgType(ASTContext &Ctx, 245 bool IsObjCLiteral) const { 246 const PrintfConversionSpecifier &CS = getConversionSpecifier(); 247 248 if (!CS.consumesDataArgument()) 249 return ArgTypeResult::Invalid(); 250 251 if (CS.getKind() == ConversionSpecifier::cArg) 252 switch (LM.getKind()) { 253 case LengthModifier::None: return Ctx.IntTy; 254 case LengthModifier::AsLong: 255 return ArgTypeResult(ArgTypeResult::WIntTy, "wint_t"); 256 default: 257 return ArgTypeResult::Invalid(); 258 } 259 260 if (CS.isIntArg()) 261 switch (LM.getKind()) { 262 case LengthModifier::AsLongDouble: 263 // GNU extension. 264 return Ctx.LongLongTy; 265 case LengthModifier::None: return Ctx.IntTy; 266 case LengthModifier::AsChar: return ArgTypeResult::AnyCharTy; 267 case LengthModifier::AsShort: return Ctx.ShortTy; 268 case LengthModifier::AsLong: return Ctx.LongTy; 269 case LengthModifier::AsLongLong: 270 case LengthModifier::AsQuad: 271 return Ctx.LongLongTy; 272 case LengthModifier::AsIntMax: 273 return ArgTypeResult(Ctx.getIntMaxType(), "intmax_t"); 274 case LengthModifier::AsSizeT: 275 // FIXME: How to get the corresponding signed version of size_t? 276 return ArgTypeResult(); 277 case LengthModifier::AsPtrDiff: 278 return ArgTypeResult(Ctx.getPointerDiffType(), "ptrdiff_t"); 279 case LengthModifier::AsAllocate: 280 case LengthModifier::AsMAllocate: 281 return ArgTypeResult::Invalid(); 282 } 283 284 if (CS.isUIntArg()) 285 switch (LM.getKind()) { 286 case LengthModifier::AsLongDouble: 287 // GNU extension. 288 return Ctx.UnsignedLongLongTy; 289 case LengthModifier::None: return Ctx.UnsignedIntTy; 290 case LengthModifier::AsChar: return Ctx.UnsignedCharTy; 291 case LengthModifier::AsShort: return Ctx.UnsignedShortTy; 292 case LengthModifier::AsLong: return Ctx.UnsignedLongTy; 293 case LengthModifier::AsLongLong: 294 case LengthModifier::AsQuad: 295 return Ctx.UnsignedLongLongTy; 296 case LengthModifier::AsIntMax: 297 return ArgTypeResult(Ctx.getUIntMaxType(), "uintmax_t"); 298 case LengthModifier::AsSizeT: 299 return ArgTypeResult(Ctx.getSizeType(), "size_t"); 300 case LengthModifier::AsPtrDiff: 301 // FIXME: How to get the corresponding unsigned 302 // version of ptrdiff_t? 303 return ArgTypeResult(); 304 case LengthModifier::AsAllocate: 305 case LengthModifier::AsMAllocate: 306 return ArgTypeResult::Invalid(); 307 } 308 309 if (CS.isDoubleArg()) { 310 if (LM.getKind() == LengthModifier::AsLongDouble) 311 return Ctx.LongDoubleTy; 312 return Ctx.DoubleTy; 313 } 314 315 switch (CS.getKind()) { 316 case ConversionSpecifier::sArg: 317 if (LM.getKind() == LengthModifier::AsWideChar) { 318 if (IsObjCLiteral) 319 return Ctx.getPointerType(Ctx.UnsignedShortTy.withConst()); 320 return ArgTypeResult(ArgTypeResult::WCStrTy, "wchar_t *"); 321 } 322 return ArgTypeResult::CStrTy; 323 case ConversionSpecifier::SArg: 324 if (IsObjCLiteral) 325 return Ctx.getPointerType(Ctx.UnsignedShortTy.withConst()); 326 return ArgTypeResult(ArgTypeResult::WCStrTy, "wchar_t *"); 327 case ConversionSpecifier::CArg: 328 if (IsObjCLiteral) 329 return Ctx.UnsignedShortTy; 330 return ArgTypeResult(Ctx.WCharTy, "wchar_t"); 331 case ConversionSpecifier::pArg: 332 return ArgTypeResult::CPointerTy; 333 case ConversionSpecifier::ObjCObjArg: 334 return ArgTypeResult::ObjCPointerTy; 335 default: 336 break; 337 } 338 339 // FIXME: Handle other cases. 340 return ArgTypeResult(); 341} 342 343bool PrintfSpecifier::fixType(QualType QT, const LangOptions &LangOpt, 344 ASTContext &Ctx, bool IsObjCLiteral) { 345 // Handle Objective-C objects first. Note that while the '%@' specifier will 346 // not warn for structure pointer or void pointer arguments (because that's 347 // how CoreFoundation objects are implemented), we only show a fixit for '%@' 348 // if we know it's an object (block, id, class, or __attribute__((NSObject))). 349 if (QT->isObjCRetainableType()) { 350 if (!IsObjCLiteral) 351 return false; 352 353 CS.setKind(ConversionSpecifier::ObjCObjArg); 354 355 // Disable irrelevant flags 356 HasThousandsGrouping = false; 357 HasPlusPrefix = false; 358 HasSpacePrefix = false; 359 HasAlternativeForm = false; 360 HasLeadingZeroes = false; 361 Precision.setHowSpecified(OptionalAmount::NotSpecified); 362 LM.setKind(LengthModifier::None); 363 364 return true; 365 } 366 367 // Handle strings next (char *, wchar_t *) 368 if (QT->isPointerType() && (QT->getPointeeType()->isAnyCharacterType())) { 369 CS.setKind(ConversionSpecifier::sArg); 370 371 // Disable irrelevant flags 372 HasAlternativeForm = 0; 373 HasLeadingZeroes = 0; 374 375 // Set the long length modifier for wide characters 376 if (QT->getPointeeType()->isWideCharType()) 377 LM.setKind(LengthModifier::AsWideChar); 378 else 379 LM.setKind(LengthModifier::None); 380 381 return true; 382 } 383 384 // We can only work with builtin types. 385 const BuiltinType *BT = QT->getAs<BuiltinType>(); 386 if (!BT) 387 return false; 388 389 // Set length modifier 390 switch (BT->getKind()) { 391 case BuiltinType::Bool: 392 case BuiltinType::WChar_U: 393 case BuiltinType::WChar_S: 394 case BuiltinType::Char16: 395 case BuiltinType::Char32: 396 case BuiltinType::UInt128: 397 case BuiltinType::Int128: 398 case BuiltinType::Half: 399 // Various types which are non-trivial to correct. 400 return false; 401 402#define SIGNED_TYPE(Id, SingletonId) 403#define UNSIGNED_TYPE(Id, SingletonId) 404#define FLOATING_TYPE(Id, SingletonId) 405#define BUILTIN_TYPE(Id, SingletonId) \ 406 case BuiltinType::Id: 407#include "clang/AST/BuiltinTypes.def" 408 // Misc other stuff which doesn't make sense here. 409 return false; 410 411 case BuiltinType::UInt: 412 case BuiltinType::Int: 413 case BuiltinType::Float: 414 case BuiltinType::Double: 415 LM.setKind(LengthModifier::None); 416 break; 417 418 case BuiltinType::Char_U: 419 case BuiltinType::UChar: 420 case BuiltinType::Char_S: 421 case BuiltinType::SChar: 422 LM.setKind(LengthModifier::AsChar); 423 break; 424 425 case BuiltinType::Short: 426 case BuiltinType::UShort: 427 LM.setKind(LengthModifier::AsShort); 428 break; 429 430 case BuiltinType::Long: 431 case BuiltinType::ULong: 432 LM.setKind(LengthModifier::AsLong); 433 break; 434 435 case BuiltinType::LongLong: 436 case BuiltinType::ULongLong: 437 LM.setKind(LengthModifier::AsLongLong); 438 break; 439 440 case BuiltinType::LongDouble: 441 LM.setKind(LengthModifier::AsLongDouble); 442 break; 443 } 444 445 // Handle size_t, ptrdiff_t, etc. that have dedicated length modifiers in C99. 446 if (isa<TypedefType>(QT) && (LangOpt.C99 || LangOpt.CPlusPlus0x)) { 447 const IdentifierInfo *Identifier = QT.getBaseTypeIdentifier(); 448 if (Identifier->getName() == "size_t") { 449 LM.setKind(LengthModifier::AsSizeT); 450 } else if (Identifier->getName() == "ssize_t") { 451 // Not C99, but common in Unix. 452 LM.setKind(LengthModifier::AsSizeT); 453 } else if (Identifier->getName() == "intmax_t") { 454 LM.setKind(LengthModifier::AsIntMax); 455 } else if (Identifier->getName() == "uintmax_t") { 456 LM.setKind(LengthModifier::AsIntMax); 457 } else if (Identifier->getName() == "ptrdiff_t") { 458 LM.setKind(LengthModifier::AsPtrDiff); 459 } 460 } 461 462 // If fixing the length modifier was enough, we are done. 463 const analyze_printf::ArgTypeResult &ATR = getArgType(Ctx, IsObjCLiteral); 464 if (hasValidLengthModifier() && ATR.isValid() && ATR.matchesType(Ctx, QT)) 465 return true; 466 467 // Set conversion specifier and disable any flags which do not apply to it. 468 // Let typedefs to char fall through to int, as %c is silly for uint8_t. 469 if (isa<TypedefType>(QT) && QT->isAnyCharacterType()) { 470 CS.setKind(ConversionSpecifier::cArg); 471 LM.setKind(LengthModifier::None); 472 Precision.setHowSpecified(OptionalAmount::NotSpecified); 473 HasAlternativeForm = 0; 474 HasLeadingZeroes = 0; 475 HasPlusPrefix = 0; 476 } 477 // Test for Floating type first as LongDouble can pass isUnsignedIntegerType 478 else if (QT->isRealFloatingType()) { 479 CS.setKind(ConversionSpecifier::fArg); 480 } 481 else if (QT->isSignedIntegerType()) { 482 CS.setKind(ConversionSpecifier::dArg); 483 HasAlternativeForm = 0; 484 } 485 else if (QT->isUnsignedIntegerType()) { 486 CS.setKind(ConversionSpecifier::uArg); 487 HasAlternativeForm = 0; 488 HasPlusPrefix = 0; 489 } else { 490 llvm_unreachable("Unexpected type"); 491 } 492 493 return true; 494} 495 496void PrintfSpecifier::toString(raw_ostream &os) const { 497 // Whilst some features have no defined order, we are using the order 498 // appearing in the C99 standard (ISO/IEC 9899:1999 (E) 7.19.6.1) 499 os << "%"; 500 501 // Positional args 502 if (usesPositionalArg()) { 503 os << getPositionalArgIndex() << "$"; 504 } 505 506 // Conversion flags 507 if (IsLeftJustified) os << "-"; 508 if (HasPlusPrefix) os << "+"; 509 if (HasSpacePrefix) os << " "; 510 if (HasAlternativeForm) os << "#"; 511 if (HasLeadingZeroes) os << "0"; 512 513 // Minimum field width 514 FieldWidth.toString(os); 515 // Precision 516 Precision.toString(os); 517 // Length modifier 518 os << LM.toString(); 519 // Conversion specifier 520 os << CS.toString(); 521} 522 523bool PrintfSpecifier::hasValidPlusPrefix() const { 524 if (!HasPlusPrefix) 525 return true; 526 527 // The plus prefix only makes sense for signed conversions 528 switch (CS.getKind()) { 529 case ConversionSpecifier::dArg: 530 case ConversionSpecifier::iArg: 531 case ConversionSpecifier::fArg: 532 case ConversionSpecifier::FArg: 533 case ConversionSpecifier::eArg: 534 case ConversionSpecifier::EArg: 535 case ConversionSpecifier::gArg: 536 case ConversionSpecifier::GArg: 537 case ConversionSpecifier::aArg: 538 case ConversionSpecifier::AArg: 539 return true; 540 541 default: 542 return false; 543 } 544} 545 546bool PrintfSpecifier::hasValidAlternativeForm() const { 547 if (!HasAlternativeForm) 548 return true; 549 550 // Alternate form flag only valid with the oxXaAeEfFgG conversions 551 switch (CS.getKind()) { 552 case ConversionSpecifier::oArg: 553 case ConversionSpecifier::xArg: 554 case ConversionSpecifier::XArg: 555 case ConversionSpecifier::aArg: 556 case ConversionSpecifier::AArg: 557 case ConversionSpecifier::eArg: 558 case ConversionSpecifier::EArg: 559 case ConversionSpecifier::fArg: 560 case ConversionSpecifier::FArg: 561 case ConversionSpecifier::gArg: 562 case ConversionSpecifier::GArg: 563 return true; 564 565 default: 566 return false; 567 } 568} 569 570bool PrintfSpecifier::hasValidLeadingZeros() const { 571 if (!HasLeadingZeroes) 572 return true; 573 574 // Leading zeroes flag only valid with the diouxXaAeEfFgG conversions 575 switch (CS.getKind()) { 576 case ConversionSpecifier::dArg: 577 case ConversionSpecifier::iArg: 578 case ConversionSpecifier::oArg: 579 case ConversionSpecifier::uArg: 580 case ConversionSpecifier::xArg: 581 case ConversionSpecifier::XArg: 582 case ConversionSpecifier::aArg: 583 case ConversionSpecifier::AArg: 584 case ConversionSpecifier::eArg: 585 case ConversionSpecifier::EArg: 586 case ConversionSpecifier::fArg: 587 case ConversionSpecifier::FArg: 588 case ConversionSpecifier::gArg: 589 case ConversionSpecifier::GArg: 590 return true; 591 592 default: 593 return false; 594 } 595} 596 597bool PrintfSpecifier::hasValidSpacePrefix() const { 598 if (!HasSpacePrefix) 599 return true; 600 601 // The space prefix only makes sense for signed conversions 602 switch (CS.getKind()) { 603 case ConversionSpecifier::dArg: 604 case ConversionSpecifier::iArg: 605 case ConversionSpecifier::fArg: 606 case ConversionSpecifier::FArg: 607 case ConversionSpecifier::eArg: 608 case ConversionSpecifier::EArg: 609 case ConversionSpecifier::gArg: 610 case ConversionSpecifier::GArg: 611 case ConversionSpecifier::aArg: 612 case ConversionSpecifier::AArg: 613 return true; 614 615 default: 616 return false; 617 } 618} 619 620bool PrintfSpecifier::hasValidLeftJustified() const { 621 if (!IsLeftJustified) 622 return true; 623 624 // The left justified flag is valid for all conversions except n 625 switch (CS.getKind()) { 626 case ConversionSpecifier::nArg: 627 return false; 628 629 default: 630 return true; 631 } 632} 633 634bool PrintfSpecifier::hasValidThousandsGroupingPrefix() const { 635 if (!HasThousandsGrouping) 636 return true; 637 638 switch (CS.getKind()) { 639 case ConversionSpecifier::dArg: 640 case ConversionSpecifier::iArg: 641 case ConversionSpecifier::uArg: 642 case ConversionSpecifier::fArg: 643 case ConversionSpecifier::FArg: 644 case ConversionSpecifier::gArg: 645 case ConversionSpecifier::GArg: 646 return true; 647 default: 648 return false; 649 } 650} 651 652bool PrintfSpecifier::hasValidPrecision() const { 653 if (Precision.getHowSpecified() == OptionalAmount::NotSpecified) 654 return true; 655 656 // Precision is only valid with the diouxXaAeEfFgGs conversions 657 switch (CS.getKind()) { 658 case ConversionSpecifier::dArg: 659 case ConversionSpecifier::iArg: 660 case ConversionSpecifier::oArg: 661 case ConversionSpecifier::uArg: 662 case ConversionSpecifier::xArg: 663 case ConversionSpecifier::XArg: 664 case ConversionSpecifier::aArg: 665 case ConversionSpecifier::AArg: 666 case ConversionSpecifier::eArg: 667 case ConversionSpecifier::EArg: 668 case ConversionSpecifier::fArg: 669 case ConversionSpecifier::FArg: 670 case ConversionSpecifier::gArg: 671 case ConversionSpecifier::GArg: 672 case ConversionSpecifier::sArg: 673 return true; 674 675 default: 676 return false; 677 } 678} 679bool PrintfSpecifier::hasValidFieldWidth() const { 680 if (FieldWidth.getHowSpecified() == OptionalAmount::NotSpecified) 681 return true; 682 683 // The field width is valid for all conversions except n 684 switch (CS.getKind()) { 685 case ConversionSpecifier::nArg: 686 return false; 687 688 default: 689 return true; 690 } 691} 692