C++ StringRef::end方法代码示例

/// Parse - Analyze the specified string (e.g. "==&{eax}") and fill in the
/// fields in this structure.  If the constraint string is not understood,
/// return true, otherwise return false.
bool InlineAsm::ConstraintInfo::Parse(StringRef Str,
                     InlineAsm::ConstraintInfoVector &ConstraintsSoFar) {
  StringRef::iterator I = Str.begin(), E = Str.end();
  unsigned multipleAlternativeCount = Str.count('|') + 1;
  unsigned multipleAlternativeIndex = 0;
  ConstraintCodeVector *pCodes = &Codes;

  // Initialize
  isMultipleAlternative = multipleAlternativeCount > 1;
  if (isMultipleAlternative) {
    multipleAlternatives.resize(multipleAlternativeCount);
    pCodes = &multipleAlternatives[0].Codes;
  }
  Type = isInput;
  isEarlyClobber = false;
  MatchingInput = -1;
  isCommutative = false;
  isIndirect = false;
  currentAlternativeIndex = 0;
  
  // Parse prefixes.
  if (*I == '~') {
    Type = isClobber;
    ++I;

    // '{' must immediately follow '~'.
    if (I != E && *I != '{')
      return true;
  } else if (*I == '=') {
    ++I;
    Type = isOutput;
  }

  if (*I == '*') {
    isIndirect = true;
    ++I;
  }

  if (I == E) return true;  // Just a prefix, like "==" or "~".
  
  // Parse the modifiers.
  bool DoneWithModifiers = false;
  while (!DoneWithModifiers) {
    switch (*I) {
    default:
      DoneWithModifiers = true;
      break;
    case '&':     // Early clobber.
      if (Type != isOutput ||      // Cannot early clobber anything but output.
          isEarlyClobber)          // Reject &&&&&&
        return true;
      isEarlyClobber = true;
      break;
    case '%':     // Commutative.
      if (Type == isClobber ||     // Cannot commute clobbers.
          isCommutative)           // Reject %%%%%
        return true;
      isCommutative = true;
      break;
    case '#':     // Comment.
    case '*':     // Register preferencing.
      return true;     // Not supported.
    }
    
    if (!DoneWithModifiers) {
      ++I;
      if (I == E) return true;   // Just prefixes and modifiers!
    }
  }
  
  // Parse the various constraints.
  while (I != E) {
    if (*I == '{') {   // Physical register reference.
      // Find the end of the register name.
      StringRef::iterator ConstraintEnd = std::find(I+1, E, '}');
      if (ConstraintEnd == E) return true;  // "{foo"
      pCodes->push_back(StringRef(I, ConstraintEnd+1 - I));
      I = ConstraintEnd+1;
    } else if (isdigit(static_cast<unsigned char>(*I))) { // Matching Constraint
      // Maximal munch numbers.
      StringRef::iterator NumStart = I;
      while (I != E && isdigit(static_cast<unsigned char>(*I)))
        ++I;
      pCodes->push_back(StringRef(NumStart, I - NumStart));
      unsigned N = atoi(pCodes->back().c_str());
      // Check that this is a valid matching constraint!
      if (N >= ConstraintsSoFar.size() || ConstraintsSoFar[N].Type != isOutput||
          Type != isInput)
        return true;  // Invalid constraint number.
      
      // If Operand N already has a matching input, reject this.  An output
      // can't be constrained to the same value as multiple inputs.
      if (isMultipleAlternative) {
        if (multipleAlternativeIndex >=
            ConstraintsSoFar[N].multipleAlternatives.size())
          return true;
        InlineAsm::SubConstraintInfo &scInfo =
//.........这里部分代码省略.........

void MCObjectStreamer::EmitBytes(StringRef Data) {
  MCLineEntry::Make(this, getCurrentSection().first);
  getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
}

error_code
MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
                                       SmallVectorImpl<char> &Result) const {
  StringRef res;
  uint64_t RType;
  getRelocationType(Rel, RType);

  unsigned Arch = this->getArch();

  switch (Arch) {
    case Triple::x86: {
      static const char *const Table[] =  {
        "GENERIC_RELOC_VANILLA",
        "GENERIC_RELOC_PAIR",
        "GENERIC_RELOC_SECTDIFF",
        "GENERIC_RELOC_PB_LA_PTR",
        "GENERIC_RELOC_LOCAL_SECTDIFF",
        "GENERIC_RELOC_TLV" };

      if (RType > 5)
        res = "Unknown";
      else
        res = Table[RType];
      break;
    }
    case Triple::x86_64: {
      static const char *const Table[] =  {
        "X86_64_RELOC_UNSIGNED",
        "X86_64_RELOC_SIGNED",
        "X86_64_RELOC_BRANCH",
        "X86_64_RELOC_GOT_LOAD",
        "X86_64_RELOC_GOT",
        "X86_64_RELOC_SUBTRACTOR",
        "X86_64_RELOC_SIGNED_1",
        "X86_64_RELOC_SIGNED_2",
        "X86_64_RELOC_SIGNED_4",
        "X86_64_RELOC_TLV" };

      if (RType > 9)
        res = "Unknown";
      else
        res = Table[RType];
      break;
    }
    case Triple::arm: {
      static const char *const Table[] =  {
        "ARM_RELOC_VANILLA",
        "ARM_RELOC_PAIR",
        "ARM_RELOC_SECTDIFF",
        "ARM_RELOC_LOCAL_SECTDIFF",
        "ARM_RELOC_PB_LA_PTR",
        "ARM_RELOC_BR24",
        "ARM_THUMB_RELOC_BR22",
        "ARM_THUMB_32BIT_BRANCH",
        "ARM_RELOC_HALF",
        "ARM_RELOC_HALF_SECTDIFF" };

      if (RType > 9)
        res = "Unknown";
      else
        res = Table[RType];
      break;
    }
    case Triple::ppc: {
      static const char *const Table[] =  {
        "PPC_RELOC_VANILLA",
        "PPC_RELOC_PAIR",
        "PPC_RELOC_BR14",
        "PPC_RELOC_BR24",
        "PPC_RELOC_HI16",
        "PPC_RELOC_LO16",
        "PPC_RELOC_HA16",
        "PPC_RELOC_LO14",
        "PPC_RELOC_SECTDIFF",
        "PPC_RELOC_PB_LA_PTR",
        "PPC_RELOC_HI16_SECTDIFF",
        "PPC_RELOC_LO16_SECTDIFF",
        "PPC_RELOC_HA16_SECTDIFF",
        "PPC_RELOC_JBSR",
        "PPC_RELOC_LO14_SECTDIFF",
        "PPC_RELOC_LOCAL_SECTDIFF" };

      if (RType > 15)
        res = "Unknown";
      else
        res = Table[RType];
      break;
    }
    case Triple::UnknownArch:
      res = "Unknown";
      break;
  }
  Result.append(res.begin(), res.end());
  return object_error::success;
}

void MCObjectStreamer::EmitBytes(StringRef Data) {
  MCLineEntry::Make(this, getCurrentSection().first);
  MCDataFragment *DF = getOrCreateDataFragment();
  flushPendingLabels(DF, DF->getContents().size());
  DF->getContents().append(Data.begin(), Data.end());
}

/// LookupFile - Lookup the specified file in this search path, returning it
/// if it exists or returning null if not.
const FileEntry *DirectoryLookup::LookupFile(
    StringRef &Filename,
    HeaderSearch &HS,
    SmallVectorImpl<char> *SearchPath,
    SmallVectorImpl<char> *RelativePath,
    ModuleMap::KnownHeader *SuggestedModule,
    bool &InUserSpecifiedSystemFramework,
    bool &HasBeenMapped,
    SmallVectorImpl<char> &MappedName) const {
  InUserSpecifiedSystemFramework = false;
  HasBeenMapped = false;

  SmallString<1024> TmpDir;
  if (isNormalDir()) {
    // Concatenate the requested file onto the directory.
    TmpDir = getDir()->getName();
    llvm::sys::path::append(TmpDir, Filename);
    if (SearchPath != NULL) {
      StringRef SearchPathRef(getDir()->getName());
      SearchPath->clear();
      SearchPath->append(SearchPathRef.begin(), SearchPathRef.end());
    }
    if (RelativePath != NULL) {
      RelativePath->clear();
      RelativePath->append(Filename.begin(), Filename.end());
    }

    return getFileAndSuggestModule(HS, TmpDir.str(), getDir(),
                                   isSystemHeaderDirectory(),
                                   SuggestedModule);
  }

  if (isFramework())
    return DoFrameworkLookup(Filename, HS, SearchPath, RelativePath,
                             SuggestedModule, InUserSpecifiedSystemFramework);

  assert(isHeaderMap() && "Unknown directory lookup");
  const HeaderMap *HM = getHeaderMap();
  SmallString<1024> Path;
  StringRef Dest = HM->lookupFilename(Filename, Path);
  if (Dest.empty())
    return 0;

  const FileEntry *Result;

  // Check if the headermap maps the filename to a framework include
  // ("Foo.h" -> "Foo/Foo.h"), in which case continue header lookup using the
  // framework include.
  if (llvm::sys::path::is_relative(Dest)) {
    MappedName.clear();
    MappedName.append(Dest.begin(), Dest.end());
    Filename = StringRef(MappedName.begin(), MappedName.size());
    HasBeenMapped = true;
    Result = HM->LookupFile(Filename, HS.getFileMgr());

  } else {
    Result = HS.getFileMgr().getFile(Dest);
  }

  if (Result) {
    if (SearchPath != NULL) {
      StringRef SearchPathRef(getName());
      SearchPath->clear();
      SearchPath->append(SearchPathRef.begin(), SearchPathRef.end());
    }
    if (RelativePath != NULL) {
      RelativePath->clear();
      RelativePath->append(Filename.begin(), Filename.end());
    }
  }
  return Result;
}

//.........这里部分代码省略.........
      Result.Val.setIsUnsigned(Literal.isUnsigned);

      // Detect overflow based on whether the value is signed.  If signed
      // and if the value is too large, emit a warning "integer constant is so
      // large that it is unsigned" e.g. on 12345678901234567890 where intmax_t
      // is 64-bits.
      if (!Literal.isUnsigned && Result.Val.isNegative()) {
        // Don't warn for a hex literal: 0x8000..0 shouldn't warn.
        if (ValueLive && Literal.getRadix() != 16)
          PP.Diag(PeekTok, diag::warn_integer_too_large_for_signed);
        Result.Val.setIsUnsigned(true);
      }
    }

    // Consume the token.
    Result.setRange(PeekTok.getLocation());
    PP.LexNonComment(PeekTok);
    return false;
  }
  case tok::char_constant:          // 'x'
  case tok::wide_char_constant:     // L'x'
  case tok::utf16_char_constant:    // u'x'
  case tok::utf32_char_constant: {  // U'x'
    // Complain about, and drop, any ud-suffix.
    if (PeekTok.hasUDSuffix())
      PP.Diag(PeekTok, diag::err_pp_invalid_udl) << /*character*/0;

    SmallString<32> CharBuffer;
    bool CharInvalid = false;
    StringRef ThisTok = PP.getSpelling(PeekTok, CharBuffer, &CharInvalid);
    if (CharInvalid)
      return true;

    CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(),
                              PeekTok.getLocation(), PP, PeekTok.getKind());
    if (Literal.hadError())
      return true;  // A diagnostic was already emitted.

    // Character literals are always int or wchar_t, expand to intmax_t.
    const TargetInfo &TI = PP.getTargetInfo();
    unsigned NumBits;
    if (Literal.isMultiChar())
      NumBits = TI.getIntWidth();
    else if (Literal.isWide())
      NumBits = TI.getWCharWidth();
    else if (Literal.isUTF16())
      NumBits = TI.getChar16Width();
    else if (Literal.isUTF32())
      NumBits = TI.getChar32Width();
    else
      NumBits = TI.getCharWidth();

    // Set the width.
    llvm::APSInt Val(NumBits);
    // Set the value.
    Val = Literal.getValue();
    // Set the signedness. UTF-16 and UTF-32 are always unsigned
    if (!Literal.isUTF16() && !Literal.isUTF32())
      Val.setIsUnsigned(!PP.getLangOpts().CharIsSigned);

    if (Result.Val.getBitWidth() > Val.getBitWidth()) {
      Result.Val = Val.extend(Result.Val.getBitWidth());
    } else {
      assert(Result.Val.getBitWidth() == Val.getBitWidth() &&
             "intmax_t smaller than char/wchar_t?");
      Result.Val = Val;

/// AnalyzeAsmString - Analyze the asm string of the current asm, decomposing
/// it into pieces.  If the asm string is erroneous, emit errors and return
/// true, otherwise return false.
unsigned GCCAsmStmt::AnalyzeAsmString(SmallVectorImpl<AsmStringPiece>&Pieces,
                                const ASTContext &C, unsigned &DiagOffs) const {
  StringRef Str = getAsmString()->getString();
  const char *StrStart = Str.begin();
  const char *StrEnd = Str.end();
  const char *CurPtr = StrStart;

  // "Simple" inline asms have no constraints or operands, just convert the asm
  // string to escape $'s.
  if (isSimple()) {
    std::string Result;
    for (; CurPtr != StrEnd; ++CurPtr) {
      switch (*CurPtr) {
      case '$':
        Result += "$$";
        break;
      default:
        Result += *CurPtr;
        break;
      }
    }
    Pieces.push_back(AsmStringPiece(Result));
    return 0;
  }

  // CurStringPiece - The current string that we are building up as we scan the
  // asm string.
  std::string CurStringPiece;

  bool HasVariants = !C.getTargetInfo().hasNoAsmVariants();

  unsigned LastAsmStringToken = 0;
  unsigned LastAsmStringOffset = 0;

  while (1) {
    // Done with the string?
    if (CurPtr == StrEnd) {
      if (!CurStringPiece.empty())
        Pieces.push_back(AsmStringPiece(CurStringPiece));
      return 0;
    }

    char CurChar = *CurPtr++;
    switch (CurChar) {
    case '$': CurStringPiece += "$$"; continue;
    case '{': CurStringPiece += (HasVariants ? "$(" : "{"); continue;
    case '|': CurStringPiece += (HasVariants ? "$|" : "|"); continue;
    case '}': CurStringPiece += (HasVariants ? "$)" : "}"); continue;
    case '%':
      break;
    default:
      CurStringPiece += CurChar;
      continue;
    }

    // Escaped "%" character in asm string.
    if (CurPtr == StrEnd) {
      // % at end of string is invalid (no escape).
      DiagOffs = CurPtr-StrStart-1;
      return diag::err_asm_invalid_escape;
    }
    // Handle escaped char and continue looping over the asm string.
    char EscapedChar = *CurPtr++;
    switch (EscapedChar) {
    default:
      break;
    case '%': // %% -> %
    case '{': // %{ -> {
    case '}': // %} -> }
      CurStringPiece += EscapedChar;
      continue;
    case '=': // %= -> Generate a unique ID.
      CurStringPiece += "${:uid}";
      continue;
    }

    // Otherwise, we have an operand.  If we have accumulated a string so far,
    // add it to the Pieces list.
    if (!CurStringPiece.empty()) {
      Pieces.push_back(AsmStringPiece(CurStringPiece));
      CurStringPiece.clear();
    }

    // Handle operands that have asmSymbolicName (e.g., %x[foo]) and those that
    // don't (e.g., %x4). 'x' following the '%' is the constraint modifier.

    const char *Begin = CurPtr - 1; // Points to the character following '%'.
    const char *Percent = Begin - 1; // Points to '%'.

    if (isLetter(EscapedChar)) {
      if (CurPtr == StrEnd) { // Premature end.
        DiagOffs = CurPtr-StrStart-1;
        return diag::err_asm_invalid_escape;
      }
      EscapedChar = *CurPtr++;
    }

//.........这里部分代码省略.........

void MCPureStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
  // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
  // MCObjectStreamer.
  getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
}

/// Parse - Analyze the specified string (e.g. "==&{eax}") and fill in the
/// fields in this structure.  If the constraint string is not understood,
/// return true, otherwise return false.
bool InlineAsm::ConstraintInfo::Parse(const StringRef &Str,
                     std::vector<InlineAsm::ConstraintInfo> &ConstraintsSoFar) {
  StringRef::iterator I = Str.begin(), E = Str.end();
  
  // Initialize
  Type = isInput;
  isEarlyClobber = false;
  MatchingInput = -1;
  isCommutative = false;
  isIndirect = false;
  
  // Parse prefixes.
  if (*I == '~') {
    Type = isClobber;
    ++I;
  } else if (*I == '=') {
    ++I;
    Type = isOutput;
  }
  
  if (*I == '*') {
    isIndirect = true;
    ++I;
  }
  
  if (I == E) return true;  // Just a prefix, like "==" or "~".
  
  // Parse the modifiers.
  bool DoneWithModifiers = false;
  while (!DoneWithModifiers) {
    switch (*I) {
    default:
      DoneWithModifiers = true;
      break;
    case '&':     // Early clobber.
      if (Type != isOutput ||      // Cannot early clobber anything but output.
          isEarlyClobber)          // Reject &&&&&&
        return true;
      isEarlyClobber = true;
      break;
    case '%':     // Commutative.
      if (Type == isClobber ||     // Cannot commute clobbers.
          isCommutative)           // Reject %%%%%
        return true;
      isCommutative = true;
      break;
    case '#':     // Comment.
    case '*':     // Register preferencing.
      return true;     // Not supported.
    }
    
    if (!DoneWithModifiers) {
      ++I;
      if (I == E) return true;   // Just prefixes and modifiers!
    }
  }
  
  // Parse the various constraints.
  while (I != E) {
    if (*I == '{') {   // Physical register reference.
      // Find the end of the register name.
      StringRef::iterator ConstraintEnd = std::find(I+1, E, '}');
      if (ConstraintEnd == E) return true;  // "{foo"
      Codes.push_back(std::string(I, ConstraintEnd+1));
      I = ConstraintEnd+1;
    } else if (isdigit(*I)) {     // Matching Constraint
      // Maximal munch numbers.
      StringRef::iterator NumStart = I;
      while (I != E && isdigit(*I))
        ++I;
      Codes.push_back(std::string(NumStart, I));
      unsigned N = atoi(Codes.back().c_str());
      // Check that this is a valid matching constraint!
      if (N >= ConstraintsSoFar.size() || ConstraintsSoFar[N].Type != isOutput||
          Type != isInput)
        return true;  // Invalid constraint number.
      
      // If Operand N already has a matching input, reject this.  An output
      // can't be constrained to the same value as multiple inputs.
      if (ConstraintsSoFar[N].hasMatchingInput())
        return true;
      
      // Note that operand #n has a matching input.
      ConstraintsSoFar[N].MatchingInput = ConstraintsSoFar.size();
    } else {
      // Single letter constraint.
      Codes.push_back(std::string(I, I+1));
      ++I;
    }
  }

  return false;
}

//.........这里部分代码省略.........
      size_t MinusLoc = FixItStr.find('-');
      if (MinusLoc == StringRef::npos) {
        addError(FixItStr.data(), "expected '-' in fix-it verification");
        continue;
      }
      StringRef StartColStr = FixItStr.slice(0, MinusLoc);
      StringRef AfterMinus = FixItStr.substr(MinusLoc+1);
      
      size_t EqualLoc = AfterMinus.find('=');
      if (EqualLoc == StringRef::npos) {
        addError(AfterMinus.data(),
                 "expected '=' after '-' in fix-it verification");
        continue;
      }
      StringRef EndColStr = AfterMinus.slice(0, EqualLoc);
      StringRef AfterEqual = AfterMinus.substr(EqualLoc+1);
      
      ExpectedFixIt FixIt;
      FixIt.StartLoc = StartColStr.data()-2;
      FixIt.EndLoc = FixItStr.data()+EndLoc;
      if (StartColStr.getAsInteger(10, FixIt.StartCol)) {
        addError(StartColStr.data(),
                 "invalid column number in fix-it verification");
        continue;
      }
      if (EndColStr.getAsInteger(10, FixIt.EndCol)) {
        addError(EndColStr.data(),
                 "invalid column number in fix-it verification");
        continue;
      }
      
      // Translate literal "\\n" into '\n', inefficiently.
      StringRef fixItText = AfterEqual.slice(0, EndLoc);
      for (const char *current = fixItText.begin(), *end = fixItText.end();
           current != end; /* in loop */) {
        if (*current == '\\' && current + 1 < end) {
          if (current[1] == 'n') {
            FixIt.Text += '\n';
            current += 2;
          } else {  // Handle \}, \\, etc.
            FixIt.Text += current[1];
            current += 2;
          }

        } else {
          FixIt.Text += *current++;
        }
      }
      
      Expected.Fixits.push_back(FixIt);
    }

    Expected.ExpectedEnd = ExtraChecks.data();
    
    // Don't include trailing whitespace in the expected-foo{{}} range.
    while (isspace(Expected.ExpectedEnd[-1]))
      --Expected.ExpectedEnd;

    // Add the diagnostic the expected number of times.
    for (; Count; --Count)
      ExpectedDiagnostics.push_back(Expected);
  }

  
  // Make sure all the expected diagnostics appeared.
  std::reverse(ExpectedDiagnostics.begin(), ExpectedDiagnostics.end());

OptTable::OptTable(const Info *_OptionInfos, unsigned _NumOptionInfos)
  : OptionInfos(_OptionInfos),
    NumOptionInfos(_NumOptionInfos),
    TheInputOptionID(0),
    TheUnknownOptionID(0),
    FirstSearchableIndex(0)
{
  // Explicitly zero initialize the error to work around a bug in array
  // value-initialization on MinGW with gcc 4.3.5.

  // Find start of normal options.
  for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
    unsigned Kind = getInfo(i + 1).Kind;
    if (Kind == Option::InputClass) {
      assert(!TheInputOptionID && "Cannot have multiple input options!");
      TheInputOptionID = getInfo(i + 1).ID;
    } else if (Kind == Option::UnknownClass) {
      assert(!TheUnknownOptionID && "Cannot have multiple unknown options!");
      TheUnknownOptionID = getInfo(i + 1).ID;
    } else if (Kind != Option::GroupClass) {
      FirstSearchableIndex = i;
      break;
    }
  }
  assert(FirstSearchableIndex != 0 && "No searchable options?");

#ifndef NDEBUG
  // Check that everything after the first searchable option is a
  // regular option class.
  for (unsigned i = FirstSearchableIndex, e = getNumOptions(); i != e; ++i) {
    Option::OptionClass Kind = (Option::OptionClass) getInfo(i + 1).Kind;
    assert((Kind != Option::InputClass && Kind != Option::UnknownClass &&
            Kind != Option::GroupClass) &&
           "Special options should be defined first!");
  }

  // Check that options are in order.
  for (unsigned i = FirstSearchableIndex+1, e = getNumOptions(); i != e; ++i) {
    if (!(getInfo(i) < getInfo(i + 1))) {
      getOption(i).dump();
      getOption(i + 1).dump();
      llvm_unreachable("Options are not in order!");
    }
  }
#endif

  // Build prefixes.
  for (unsigned i = FirstSearchableIndex+1, e = getNumOptions(); i != e; ++i) {
    if (const char *const *P = getInfo(i).Prefixes) {
      for (; *P != 0; ++P) {
        PrefixesUnion.insert(*P);
      }
    }
  }

  // Build prefix chars.
  for (llvm::StringSet<>::const_iterator I = PrefixesUnion.begin(),
                                         E = PrefixesUnion.end(); I != E; ++I) {
    StringRef Prefix = I->getKey();
    for (StringRef::const_iterator C = Prefix.begin(), CE = Prefix.end();
                                   C != CE; ++C)
      if (std::find(PrefixChars.begin(), PrefixChars.end(), *C)
            == PrefixChars.end())
        PrefixChars.push_back(*C);
  }
}

/// parseDirectiveSection:
///   ::= .section identifier (',' identifier)*
bool DarwinAsmParser::parseDirectiveSection(StringRef, SMLoc) {
    SMLoc Loc = getLexer().getLoc();

    StringRef SectionName;
    if (getParser().parseIdentifier(SectionName))
        return Error(Loc, "expected identifier after '.section' directive");

    // Verify there is a following comma.
    if (!getLexer().is(AsmToken::Comma))
        return TokError("unexpected token in '.section' directive");

    std::string SectionSpec = SectionName;
    SectionSpec += ",";

    // Add all the tokens until the end of the line, ParseSectionSpecifier will
    // handle this.
    StringRef EOL = getLexer().LexUntilEndOfStatement();
    SectionSpec.append(EOL.begin(), EOL.end());

    Lex();
    if (getLexer().isNot(AsmToken::EndOfStatement))
        return TokError("unexpected token in '.section' directive");
    Lex();


    StringRef Segment, Section;
    unsigned StubSize;
    unsigned TAA;
    bool TAAParsed;
    std::string ErrorStr =
        MCSectionMachO::ParseSectionSpecifier(SectionSpec, Segment, Section,
                TAA, TAAParsed, StubSize);

    if (!ErrorStr.empty())
        return Error(Loc, ErrorStr);

    // Issue a warning if the target is not powerpc and Section is a *coal* section.
    Triple TT = getParser().getContext().getObjectFileInfo()->getTargetTriple();
    Triple::ArchType ArchTy = TT.getArch();

    if (ArchTy != Triple::ppc && ArchTy != Triple::ppc64) {
        StringRef NonCoalSection = StringSwitch<StringRef>(Section)
                                   .Case("__textcoal_nt", "__text")
                                   .Case("__const_coal", "__const")
                                   .Case("__datacoal_nt", "__data")
                                   .Default(Section);

        if (!Section.equals(NonCoalSection)) {
            StringRef SectionVal(Loc.getPointer());
            size_t B = SectionVal.find(',') + 1, E = SectionVal.find(',', B);
            SMLoc BLoc = SMLoc::getFromPointer(SectionVal.data() + B);
            SMLoc ELoc = SMLoc::getFromPointer(SectionVal.data() + E);
            getParser().Warning(Loc, "section \"" + Section + "\" is deprecated",
                                SMRange(BLoc, ELoc));
            getParser().Note(Loc, "change section name to \"" + NonCoalSection +
                             "\"", SMRange(BLoc, ELoc));
        }
    }

    // FIXME: Arch specific.
    bool isText = Segment == "__TEXT";  // FIXME: Hack.
    getStreamer().SwitchSection(getContext().getMachOSection(
                                    Segment, Section, TAA, StubSize,
                                    isText ? SectionKind::getText() : SectionKind::getData()));
    return false;
}

/// AnalyzeAsmString - Analyze the asm string of the current asm, decomposing
/// it into pieces.  If the asm string is erroneous, emit errors and return
/// true, otherwise return false.
unsigned AsmStmt::AnalyzeAsmString(SmallVectorImpl<AsmStringPiece>&Pieces,
                                   ASTContext &C, unsigned &DiagOffs) const {
  StringRef Str = getAsmString()->getString();
  const char *StrStart = Str.begin();
  const char *StrEnd = Str.end();
  const char *CurPtr = StrStart;

  // "Simple" inline asms have no constraints or operands, just convert the asm
  // string to escape $'s.
  if (isSimple()) {
    std::string Result;
    for (; CurPtr != StrEnd; ++CurPtr) {
      switch (*CurPtr) {
      case '$':
        Result += "$$";
        break;
      default:
        Result += *CurPtr;
        break;
      }
    }
    Pieces.push_back(AsmStringPiece(Result));
    return 0;
  }

  // CurStringPiece - The current string that we are building up as we scan the
  // asm string.
  std::string CurStringPiece;

  bool HasVariants = !C.getTargetInfo().hasNoAsmVariants();
  
  while (1) {
    // Done with the string?
    if (CurPtr == StrEnd) {
      if (!CurStringPiece.empty())
        Pieces.push_back(AsmStringPiece(CurStringPiece));
      return 0;
    }

    char CurChar = *CurPtr++;
    switch (CurChar) {
    case '$': CurStringPiece += "$$"; continue;
    case '{': CurStringPiece += (HasVariants ? "$(" : "{"); continue;
    case '|': CurStringPiece += (HasVariants ? "$|" : "|"); continue;
    case '}': CurStringPiece += (HasVariants ? "$)" : "}"); continue;
    case '%':
      break;
    default:
      CurStringPiece += CurChar;
      continue;
    }
    
    // Escaped "%" character in asm string.
    if (CurPtr == StrEnd) {
      // % at end of string is invalid (no escape).
      DiagOffs = CurPtr-StrStart-1;
      return diag::err_asm_invalid_escape;
    }

    char EscapedChar = *CurPtr++;
    if (EscapedChar == '%') {  // %% -> %
      // Escaped percentage sign.
      CurStringPiece += '%';
      continue;
    }

    if (EscapedChar == '=') {  // %= -> Generate an unique ID.
      CurStringPiece += "${:uid}";
      continue;
    }

    // Otherwise, we have an operand.  If we have accumulated a string so far,
    // add it to the Pieces list.
    if (!CurStringPiece.empty()) {
      Pieces.push_back(AsmStringPiece(CurStringPiece));
      CurStringPiece.clear();
    }

    // Handle %x4 and %x[foo] by capturing x as the modifier character.
    char Modifier = '\0';
    if (isalpha(EscapedChar)) {
      if (CurPtr == StrEnd) { // Premature end.
        DiagOffs = CurPtr-StrStart-1;
        return diag::err_asm_invalid_escape;
      }
      Modifier = EscapedChar;
      EscapedChar = *CurPtr++;
    }

    if (isdigit(EscapedChar)) {
      // %n - Assembler operand n
      unsigned N = 0;

      --CurPtr;
      while (CurPtr != StrEnd && isdigit(*CurPtr))
        N = N*10 + ((*CurPtr++)-'0');

//.........这里部分代码省略.........

// Returns true if S is valid as a C language identifier.
bool elf::isValidCIdentifier(StringRef S) {
  return !S.empty() && isAlpha(S[0]) &&
         std::all_of(S.begin() + 1, S.end(), isAlnum);
}

void HTMLDiagnostics::HandlePiece(Rewriter& R, FileID BugFileID,
                                  const PathDiagnosticPiece& P,
                                  unsigned num, unsigned max) {

    // For now, just draw a box above the line in question, and emit the
    // warning.
    FullSourceLoc Pos = P.getLocation().asLocation();

    if (!Pos.isValid())
        return;

    SourceManager &SM = R.getSourceMgr();
    assert(&Pos.getManager() == &SM && "SourceManagers are different!");
    std::pair<FileID, unsigned> LPosInfo = SM.getDecomposedExpansionLoc(Pos);

    if (LPosInfo.first != BugFileID)
        return;

    const llvm::MemoryBuffer *Buf = SM.getBuffer(LPosInfo.first);
    const char* FileStart = Buf->getBufferStart();

    // Compute the column number.  Rewind from the current position to the start
    // of the line.
    unsigned ColNo = SM.getColumnNumber(LPosInfo.first, LPosInfo.second);
    const char *TokInstantiationPtr =Pos.getExpansionLoc().getCharacterData();
    const char *LineStart = TokInstantiationPtr-ColNo;

    // Compute LineEnd.
    const char *LineEnd = TokInstantiationPtr;
    const char* FileEnd = Buf->getBufferEnd();
    while (*LineEnd != '\n' && LineEnd != FileEnd)
        ++LineEnd;

    // Compute the margin offset by counting tabs and non-tabs.
    unsigned PosNo = 0;
    for (const char* c = LineStart; c != TokInstantiationPtr; ++c)
        PosNo += *c == '\t' ? 8 : 1;

    // Create the html for the message.

    const char *Kind = nullptr;
    switch (P.getKind()) {
    case PathDiagnosticPiece::Call:
        llvm_unreachable("Calls should already be handled");
    case PathDiagnosticPiece::Event:
        Kind = "Event";
        break;
    case PathDiagnosticPiece::ControlFlow:
        Kind = "Control";
        break;
    // Setting Kind to "Control" is intentional.
    case PathDiagnosticPiece::Macro:
        Kind = "Control";
        break;
    }

    std::string sbuf;
    llvm::raw_string_ostream os(sbuf);

    os << "\n<tr><td class=\"num\"></td><td class=\"line\"><div id=\"";

    if (num == max)
        os << "EndPath";
    else
        os << "Path" << num;

    os << "\" class=\"msg";
    if (Kind)
        os << " msg" << Kind;
    os << "\" style=\"margin-left:" << PosNo << "ex";

    // Output a maximum size.
    if (!isa<PathDiagnosticMacroPiece>(P)) {
        // Get the string and determining its maximum substring.
        const std::string& Msg = P.getString();
        unsigned max_token = 0;
        unsigned cnt = 0;
        unsigned len = Msg.size();

        for (std::string::const_iterator I=Msg.begin(), E=Msg.end(); I!=E; ++I)
            switch (*I) {
            default:
                ++cnt;
                continue;
            case ' ':
            case '\t':
            case '\n':
                if (cnt > max_token) max_token = cnt;
                cnt = 0;
            }

        if (cnt > max_token)
            max_token = cnt;

        // Determine the approximate size of the message bubble in em.
        unsigned em;
        const unsigned max_line = 120;

        if (max_token >= max_line)
            em = max_token / 2;
//.........这里部分代码省略.........