C++ SMLoc::getPointer方法代码示例

OperandMatchResultTy BPFAsmParser::parseRegister(OperandVector &Operands) {
  SMLoc S = getLoc();
  SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);

  switch (getLexer().getKind()) {
  default:
    return MatchOperand_NoMatch;
  case AsmToken::Identifier:
    StringRef Name = getLexer().getTok().getIdentifier();
    unsigned RegNo = MatchRegisterName(Name);

    if (RegNo == 0)
      return MatchOperand_NoMatch;

    getLexer().Lex();
    Operands.push_back(BPFOperand::createReg(RegNo, S, E));
  }
  return MatchOperand_Success;
}

/// ParseInstruction - Parse an BPF instruction which is in BPF verifier
/// format.
bool BPFAsmParser::ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
                                    SMLoc NameLoc, OperandVector &Operands) {
  // The first operand could be either register or actually an operator.
  unsigned RegNo = MatchRegisterName(Name);

  if (RegNo != 0) {
    SMLoc E = SMLoc::getFromPointer(NameLoc.getPointer() - 1);
    Operands.push_back(BPFOperand::createReg(RegNo, NameLoc, E));
  } else if (BPFOperand::isValidIdAtStart (Name))
    Operands.push_back(BPFOperand::createToken(Name, NameLoc));
  else
    return Error(NameLoc, "invalid register/token name");

  while (!getLexer().is(AsmToken::EndOfStatement)) {
    // Attempt to parse token as operator
    if (parseOperandAsOperator(Operands) == MatchOperand_Success)
      continue;

    // Attempt to parse token as register
    if (parseRegister(Operands) == MatchOperand_Success)
      continue;

    // Attempt to parse token as an immediate
    if (parseImmediate(Operands) != MatchOperand_Success) {
      SMLoc Loc = getLexer().getLoc();
      return Error(Loc, "unexpected token");
    }
  }

  if (getLexer().isNot(AsmToken::EndOfStatement)) {
    SMLoc Loc = getLexer().getLoc();

    getParser().eatToEndOfStatement();

    return Error(Loc, "unexpected token");
  }

  // Consume the EndOfStatement.
  getParser().Lex();
  return false;
}

int TGLexer::getNextChar() {
  char CurChar = *CurPtr++;
  switch (CurChar) {
  default:
    return (unsigned char)CurChar;
  case 0: {
    // A nul character in the stream is either the end of the current buffer or
    // a random nul in the file.  Disambiguate that here.
    if (CurPtr-1 != CurBuf->getBufferEnd())
      return 0;  // Just whitespace.
    
    // If this is the end of an included file, pop the parent file off the
    // include stack.
    SMLoc ParentIncludeLoc = SrcMgr.getParentIncludeLoc(CurBuffer);
    if (ParentIncludeLoc != SMLoc()) {
      CurBuffer = SrcMgr.FindBufferContainingLoc(ParentIncludeLoc);
      CurBuf = SrcMgr.getMemoryBuffer(CurBuffer);
      CurPtr = ParentIncludeLoc.getPointer();
      return getNextChar();
    }
    
    // Otherwise, return end of file.
    --CurPtr;  // Another call to lex will return EOF again.  
    return EOF;
  }
  case '\n':
  case '\r':
    // Handle the newline character by ignoring it and incrementing the line
    // count.  However, be careful about 'dos style' files with \n\r in them.
    // Only treat a \n\r or \r\n as a single line.
    if ((*CurPtr == '\n' || (*CurPtr == '\r')) &&
        *CurPtr != CurChar)
      ++CurPtr;  // Eat the two char newline sequence.
    return '\n';
  }  
}

OperandMatchResultTy BPFAsmParser::parseImmediate(OperandVector &Operands) {
  switch (getLexer().getKind()) {
  default:
    return MatchOperand_NoMatch;
  case AsmToken::LParen:
  case AsmToken::Minus:
  case AsmToken::Plus:
  case AsmToken::Integer:
  case AsmToken::String:
  case AsmToken::Identifier:
    break;
  }

  const MCExpr *IdVal;
  SMLoc S = getLoc();

  if (getParser().parseExpression(IdVal))
    return MatchOperand_ParseFail;

  SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
  Operands.push_back(BPFOperand::createImm(IdVal, S, E));

  return MatchOperand_Success;
}

SMDiagnostic SourceMgr::GetMessage(SMLoc Loc, SourceMgr::DiagKind Kind,
                                   const Twine &Msg,
                                   ArrayRef<SMRange> Ranges,
                                   ArrayRef<SMFixIt> FixIts) const {

  // First thing to do: find the current buffer containing the specified
  // location to pull out the source line.
  SmallVector<std::pair<unsigned, unsigned>, 4> ColRanges;
  std::pair<unsigned, unsigned> LineAndCol;
  const char *BufferID = "<unknown>";
  std::string LineStr;
  
  if (Loc.isValid()) {
    unsigned CurBuf = FindBufferContainingLoc(Loc);
    assert(CurBuf && "Invalid or unspecified location!");

    const MemoryBuffer *CurMB = getMemoryBuffer(CurBuf);
    BufferID = CurMB->getBufferIdentifier();
    
    // Scan backward to find the start of the line.
    const char *LineStart = Loc.getPointer();
    const char *BufStart = CurMB->getBufferStart();
    while (LineStart != BufStart && LineStart[-1] != '\n' &&
           LineStart[-1] != '\r')
      --LineStart;

    // Get the end of the line.
    const char *LineEnd = Loc.getPointer();
    const char *BufEnd = CurMB->getBufferEnd();
    while (LineEnd != BufEnd && LineEnd[0] != '\n' && LineEnd[0] != '\r')
      ++LineEnd;
    LineStr = std::string(LineStart, LineEnd);

    // Convert any ranges to column ranges that only intersect the line of the
    // location.
    for (unsigned i = 0, e = Ranges.size(); i != e; ++i) {
      SMRange R = Ranges[i];
      if (!R.isValid()) continue;
      
      // If the line doesn't contain any part of the range, then ignore it.
      if (R.Start.getPointer() > LineEnd || R.End.getPointer() < LineStart)
        continue;
     
      // Ignore pieces of the range that go onto other lines.
      if (R.Start.getPointer() < LineStart)
        R.Start = SMLoc::getFromPointer(LineStart);
      if (R.End.getPointer() > LineEnd)
        R.End = SMLoc::getFromPointer(LineEnd);
      
      // Translate from SMLoc ranges to column ranges.
      // FIXME: Handle multibyte characters.
      ColRanges.push_back(std::make_pair(R.Start.getPointer()-LineStart,
                                         R.End.getPointer()-LineStart));
    }

    LineAndCol = getLineAndColumn(Loc, CurBuf);
  }
    
  return SMDiagnostic(*this, Loc, BufferID, LineAndCol.first,
                      LineAndCol.second-1, Kind, Msg.str(),
                      LineStr, ColRanges, FixIts);
}

/// 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.c_str());

  // 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::getDataRel()));
  return false;
}