C++ SMLoc类代码示例

/// FindBufferContainingLoc - Return the ID of the buffer containing the
/// specified location, returning -1 if not found.
int SourceMgr::FindBufferContainingLoc(SMLoc Loc) const {
  for (unsigned i = 0, e = Buffers.size(); i != e; ++i)
    if (Loc.getPointer() >= Buffers[i].Buffer->getBufferStart() &&
        // Use <= here so that a pointer to the null at the end of the buffer
        // is included as part of the buffer.
        Loc.getPointer() <= Buffers[i].Buffer->getBufferEnd())
      return i;
  return -1;
}

/// GetMessage - Return an SMDiagnostic at the specified location with the
/// specified string.
///
/// @param Type - If non-null, the kind of message (e.g., "error") which is
/// prefixed to the message.
SMDiagnostic SourceMgr::GetMessage(SMLoc Loc, SourceMgr::DiagKind Kind,
                                   const Twine &Msg,
                                   ArrayRef<SMRange> Ranges) const {

  // First thing to do: find the current buffer containing the specified
  // location.
  int CurBuf = FindBufferContainingLoc(Loc);
  assert(CurBuf != -1 && "Invalid or unspecified location!");

  MemoryBuffer *CurMB = getBufferInfo(CurBuf).Buffer;

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

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

  // Convert any ranges to column ranges that only intersect the line of the
  // location.
  SmallVector<std::pair<unsigned, unsigned>, 4> ColRanges;
  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.
    ColRanges.push_back(std::make_pair(R.Start.getPointer()-LineStart,
                                       R.End.getPointer()-LineStart));
  }
  
  return SMDiagnostic(*this, Loc,
                      CurMB->getBufferIdentifier(), FindLineNumber(Loc, CurBuf),
                      Loc.getPointer()-LineStart, Kind, Msg.str(),
                      LineStr, ColRanges);
}

SMDiagnostic MIRParserImpl::diagFromMIStringDiag(const SMDiagnostic &Error,
                                                 SMRange SourceRange) {
  assert(SourceRange.isValid() && "Invalid source range");
  SMLoc Loc = SourceRange.Start;
  bool HasQuote = Loc.getPointer() < SourceRange.End.getPointer() &&
                  *Loc.getPointer() == '\'';
  // Translate the location of the error from the location in the MI string to
  // the corresponding location in the MIR file.
  Loc = Loc.getFromPointer(Loc.getPointer() + Error.getColumnNo() +
                           (HasQuote ? 1 : 0));

  // TODO: Translate any source ranges as well.
  return SM.GetMessage(Loc, Error.getKind(), Error.getMessage(), None,
                       Error.getFixIts());
}

std::pair<unsigned, unsigned>
SourceMgr::getLineAndColumn(SMLoc Loc, unsigned BufferID) const {
  if (!BufferID)
    BufferID = FindBufferContainingLoc(Loc);
  assert(BufferID && "Invalid Location!");

  auto &SB = getBufferInfo(BufferID);
  const char *Ptr = Loc.getPointer();

  size_t Sz = SB.Buffer->getBufferSize();
  assert(Sz <= std::numeric_limits<uint64_t>::max());
  unsigned LineNo;
  if (Sz <= std::numeric_limits<uint8_t>::max())
    LineNo = SB.getLineNumber<uint8_t>(Ptr);
  else if (Sz <= std::numeric_limits<uint16_t>::max())
    LineNo = SB.getLineNumber<uint16_t>(Ptr);
  else if (Sz <= std::numeric_limits<uint32_t>::max())
    LineNo = SB.getLineNumber<uint32_t>(Ptr);
  else
    LineNo = SB.getLineNumber<uint64_t>(Ptr);

  const char *BufStart = SB.Buffer->getBufferStart();
  size_t NewlineOffs = StringRef(BufStart, Ptr-BufStart).find_last_of("\n\r");
  if (NewlineOffs == StringRef::npos) NewlineOffs = ~(size_t)0;
  return std::make_pair(LineNo, Ptr-BufStart-NewlineOffs);
}

/// Parse an instruction mnemonic followed by its operands.
bool PPCAsmParser::
ParseInstruction(ParseInstructionInfo &Info, StringRef Name, SMLoc NameLoc,
                 SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
  // The first operand is the token for the instruction name.
  // If the instruction ends in a '.', we need to create a separate
  // token for it, to match what TableGen is doing.
  size_t Dot = Name.find('.');
  StringRef Mnemonic = Name.slice(0, Dot);
  Operands.push_back(PPCOperand::CreateToken(Mnemonic, NameLoc, isPPC64()));
  if (Dot != StringRef::npos) {
    SMLoc DotLoc = SMLoc::getFromPointer(NameLoc.getPointer() + Dot);
    StringRef DotStr = Name.slice(Dot, StringRef::npos);
    Operands.push_back(PPCOperand::CreateToken(DotStr, DotLoc, isPPC64()));
  }

  // If there are no more operands then finish
  if (getLexer().is(AsmToken::EndOfStatement))
    return false;

  // Parse the first operand
  if (ParseOperand(Operands))
    return true;

  while (getLexer().isNot(AsmToken::EndOfStatement) &&
         getLexer().is(AsmToken::Comma)) {
    // Consume the comma token
    getLexer().Lex();

    // Parse the next operand
    if (ParseOperand(Operands))
      return true;
  }

  return false;
}

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;
}

bool ELFAsmParser::ParseSectionName(StringRef &SectionName) {
  // A section name can contain -, so we cannot just use
  // ParseIdentifier.
  SMLoc FirstLoc = getLexer().getLoc();
  unsigned Size = 0;

  if (getLexer().is(AsmToken::String)) {
    SectionName = getTok().getIdentifier();
    Lex();
    return false;
  }

  for (;;) {
    StringRef Tmp;
    unsigned CurSize;

    SMLoc PrevLoc = getLexer().getLoc();
    if (getLexer().is(AsmToken::Minus)) {
      CurSize = 1;
      Lex(); // Consume the "-".
    } else if (getLexer().is(AsmToken::String)) {
      CurSize = getTok().getIdentifier().size() + 2;
      Lex();
    } else if (getLexer().is(AsmToken::Identifier)) {
      CurSize = getTok().getIdentifier().size();
      Lex();
    } else {
      break;
    }

    Size += CurSize;
    SectionName = StringRef(FirstLoc.getPointer(), Size);

    // Make sure the following token is adjacent.
    if (PrevLoc.getPointer() + CurSize != getTok().getLoc().getPointer())
      break;
  }
  if (Size == 0)
    return true;

  return false;
}

bool ELFAsmParser::ParseSectionName(StringRef &SectionName) {
  // A section name can contain -, so we cannot just use
  // parseIdentifier.
  SMLoc FirstLoc = getLexer().getLoc();
  unsigned Size = 0;

  if (getLexer().is(AsmToken::String)) {
    SectionName = getTok().getIdentifier();
    Lex();
    return false;
  }

  while (!getParser().hasPendingError()) {
    SMLoc PrevLoc = getLexer().getLoc();
    if (getLexer().is(AsmToken::Comma) ||
      getLexer().is(AsmToken::EndOfStatement))
      break;

    unsigned CurSize;
    if (getLexer().is(AsmToken::String)) {
      CurSize = getTok().getIdentifier().size() + 2;
      Lex();
    } else if (getLexer().is(AsmToken::Identifier)) {
      CurSize = getTok().getIdentifier().size();
      Lex();
    } else {
      CurSize = getTok().getString().size();
      Lex();
    }
    Size += CurSize;
    SectionName = StringRef(FirstLoc.getPointer(), Size);

    // Make sure the following token is adjacent.
    if (PrevLoc.getPointer() + CurSize != getTok().getLoc().getPointer())
      break;
  }
  if (Size == 0)
    return true;

  return false;
}

/// GetMessage - Return an SMDiagnostic at the specified location with the
/// specified string.
///
/// @param Type - If non-null, the kind of message (e.g., "error") which is
/// prefixed to the message.
SMDiagnostic SourceMgr::GetMessage(SMLoc Loc, const Twine &Msg,
                                   const char *Type, bool ShowLine) const {

  // First thing to do: find the current buffer containing the specified
  // location.
  int CurBuf = FindBufferContainingLoc(Loc);
  assert(CurBuf != -1 && "Invalid or unspecified location!");

  MemoryBuffer *CurMB = getBufferInfo(CurBuf).Buffer;

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

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

  std::string PrintedMsg;
  raw_string_ostream OS(PrintedMsg);
  if (Type)
    OS << Type << ": ";
  OS << Msg;

  return SMDiagnostic(*this, Loc,
                      CurMB->getBufferIdentifier(), FindLineNumber(Loc, CurBuf),
                      Loc.getPointer()-LineStart, OS.str(),
                      LineStr, ShowLine);
}

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;
}

std::pair<unsigned, unsigned>
SourceMgr::getLineAndColumn(SMLoc Loc, unsigned BufferID) const {
  if (!BufferID)
    BufferID = FindBufferContainingLoc(Loc);
  assert(BufferID && "Invalid Location!");

  const MemoryBuffer *Buff = getMemoryBuffer(BufferID);

  // Count the number of \n's between the start of the file and the specified
  // location.
  unsigned LineNo = 1;

  const char *BufStart = Buff->getBufferStart();
  const char *Ptr = BufStart;

  // If we have a line number cache, and if the query is to a later point in the
  // same file, start searching from the last query location.  This optimizes
  // for the case when multiple diagnostics come out of one file in order.
  if (LineNoCacheTy *Cache = getCache(LineNoCache))
    if (Cache->LastQueryBufferID == BufferID &&
        Cache->LastQuery <= Loc.getPointer()) {
      Ptr = Cache->LastQuery;
      LineNo = Cache->LineNoOfQuery;
    }

  // Scan for the location being queried, keeping track of the number of lines
  // we see.
  for (; SMLoc::getFromPointer(Ptr) != Loc; ++Ptr)
    if (*Ptr == '\n') ++LineNo;

  // Allocate the line number cache if it doesn't exist.
  if (!LineNoCache)
    LineNoCache = new LineNoCacheTy();

  // Update the line # cache.
  LineNoCacheTy &Cache = *getCache(LineNoCache);
  Cache.LastQueryBufferID = BufferID;
  Cache.LastQuery = Ptr;
  Cache.LineNoOfQuery = LineNo;
  
  size_t NewlineOffs = StringRef(BufStart, Ptr-BufStart).find_last_of("\n\r");
  if (NewlineOffs == StringRef::npos) NewlineOffs = ~(size_t)0;
  return std::make_pair(LineNo, Ptr-BufStart-NewlineOffs);
}

/// 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;
}

/// FindLineNumber - Find the line number for the specified location in the
/// specified file.  This is not a fast method.
unsigned SourceMgr::FindLineNumber(SMLoc Loc, int BufferID) const {
  if (BufferID == -1) BufferID = FindBufferContainingLoc(Loc);
  assert(BufferID != -1 && "Invalid Location!");

  MemoryBuffer *Buff = getBufferInfo(BufferID).Buffer;

  // Count the number of \n's between the start of the file and the specified
  // location.
  unsigned LineNo = 1;

  const char *Ptr = Buff->getBufferStart();

  // If we have a line number cache, and if the query is to a later point in the
  // same file, start searching from the last query location.  This optimizes
  // for the case when multiple diagnostics come out of one file in order.
  if (LineNoCacheTy *Cache = getCache(LineNoCache))
    if (Cache->LastQueryBufferID == BufferID &&
        Cache->LastQuery <= Loc.getPointer()) {
      Ptr = Cache->LastQuery;
      LineNo = Cache->LineNoOfQuery;
    }

  // Scan for the location being queried, keeping track of the number of lines
  // we see.
  for (; SMLoc::getFromPointer(Ptr) != Loc; ++Ptr)
    if (*Ptr == '\n') ++LineNo;


  // Allocate the line number cache if it doesn't exist.
  if (LineNoCache == 0)
    LineNoCache = new LineNoCacheTy();

  // Update the line # cache.
  LineNoCacheTy &Cache = *getCache(LineNoCache);
  Cache.LastQueryBufferID = BufferID;
  Cache.LastQuery = Ptr;
  Cache.LineNoOfQuery = LineNo;
  return LineNo;
}

/// 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;
}