C++ StringRef::find_first_of方法代码示例

static void escapeAndPrintString(llvm::raw_ostream &os, StringRef Str) {
  if (Str.empty()) {
    // Special-case the empty string.
    os << "\"\"";
    return;
  }

  bool NeedsEscape = Str.find_first_of(" \"\\$") != StringRef::npos;

  if (!NeedsEscape) {
    // This string doesn't have anything we need to escape, so print it directly
    os << Str;
    return;
  }

  // Quote and escape. This isn't really complete, but is good enough, and
  // matches how Clang's Command handles escaping arguments.
  os << '"';
  for (const char c : Str) {
    switch (c) {
    case '"':
    case '\\':
    case '$':
      // These characters need to be escaped.
      os << '\\';
      // Fall-through to the default case, since we still need to print the
      // character.
      SWIFT_FALLTHROUGH;
    default:
      os << c;
    }
  }
  os << '"';
}

std::string get_line_from_offset(StringRef buffer, std::size_t offset) {
    assert(buffer.size() > offset);

    auto line_start = buffer.find_last_of("\r\n", offset) + 1;
    auto line_end = buffer.find_first_of("\r\n", offset);
    return std::string(buffer.begin() + line_start, buffer.begin() + line_end);
}

/// Print the filename, with escaping or quoting that accommodates the three
/// most likely tools that use dependency files: GNU Make, BSD Make, and
/// NMake/Jom.
///
/// BSD Make is the simplest case: It does no escaping at all.  This means
/// characters that are normally delimiters, i.e. space and # (the comment
/// character) simply aren't supported in filenames.
///
/// GNU Make does allow space and # in filenames, but to avoid being treated
/// as a delimiter or comment, these must be escaped with a backslash. Because
/// backslash is itself the escape character, if a backslash appears in a
/// filename, it should be escaped as well.  (As a special case, $ is escaped
/// as $$, which is the normal Make way to handle the $ character.)
/// For compatibility with BSD Make and historical practice, if GNU Make
/// un-escapes characters in a filename but doesn't find a match, it will
/// retry with the unmodified original string.
///
/// GCC tries to accommodate both Make formats by escaping any space or #
/// characters in the original filename, but not escaping backslashes.  The
/// apparent intent is so that filenames with backslashes will be handled
/// correctly by BSD Make, and by GNU Make in its fallback mode of using the
/// unmodified original string; filenames with # or space characters aren't
/// supported by BSD Make at all, but will be handled correctly by GNU Make
/// due to the escaping.
///
/// A corner case that GCC gets only partly right is when the original filename
/// has a backslash immediately followed by space or #.  GNU Make would expect
/// this backslash to be escaped; however GCC escapes the original backslash
/// only when followed by space, not #.  It will therefore take a dependency
/// from a directive such as
///     #include "a\ b\#c.h"
/// and emit it as
///     a\\\ b\\#c.h
/// which GNU Make will interpret as
///     a\ b\
/// followed by a comment. Failing to find this file, it will fall back to the
/// original string, which probably doesn't exist either; in any case it won't
/// find
///     a\ b\#c.h
/// which is the actual filename specified by the include directive.
///
/// Clang does what GCC does, rather than what GNU Make expects.
///
/// NMake/Jom has a different set of scary characters, but wraps filespecs in
/// double-quotes to avoid misinterpreting them; see
/// https://msdn.microsoft.com/en-us/library/dd9y37ha.aspx for NMake info,
/// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx
/// for Windows file-naming info.
static void PrintFilename(raw_ostream &OS, StringRef Filename,
                          DependencyOutputFormat OutputFormat) {
  if (OutputFormat == DependencyOutputFormat::NMake) {
    // Add quotes if needed. These are the characters listed as "special" to
    // NMake, that are legal in a Windows filespec, and that could cause
    // misinterpretation of the dependency string.
    if (Filename.find_first_of(" #${}^!") != StringRef::npos)
      OS << '\"' << Filename << '\"';
    else
      OS << Filename;
    return;
  }
  assert(OutputFormat == DependencyOutputFormat::Make);
  for (unsigned i = 0, e = Filename.size(); i != e; ++i) {
    if (Filename[i] == '#') // Handle '#' the broken gcc way.
      OS << '\\';
    else if (Filename[i] == ' ') { // Handle space correctly.
      OS << '\\';
      unsigned j = i;
      while (j > 0 && Filename[--j] == '\\')
        OS << '\\';
    } else if (Filename[i] == '$') // $ is escaped by $$.
      OS << '$';
    OS << Filename[i];
  }
}

static bool ByteArrayFromString(ByteArrayTy &ByteArray,
                                StringRef &Str,
                                SourceMgr &SM) {
  while (SkipToToken(Str)) {
    // Handled by higher level
    if (Str[0] == '[' || Str[0] == ']')
      return false;

    // Get the current token.
    size_t Next = Str.find_first_of(" \t\n\r,#[]");
    StringRef Value = Str.substr(0, Next);

    // Convert to a byte and add to the byte vector.
    unsigned ByteVal;
    if (Value.getAsInteger(0, ByteVal) || ByteVal > 255) {
      // If we have an error, print it and skip to the end of line.
      SM.PrintMessage(SMLoc::getFromPointer(Value.data()), SourceMgr::DK_Error,
                      "invalid input token");
      Str = Str.substr(Str.find('\n'));
      ByteArray.first.clear();
      ByteArray.second.clear();
      continue;
    }

    ByteArray.first.push_back(ByteVal);
    ByteArray.second.push_back(Value.data());
    Str = Str.substr(Next);
  }

  return false;
}

// Returns a whole line containing the current token.
StringRef ScriptParserBase::getLine() {
  StringRef S = getCurrentMB().getBuffer();
  StringRef Tok = Tokens[Pos - 1];

  size_t Pos = S.rfind('\n', Tok.data() - S.data());
  if (Pos != StringRef::npos)
    S = S.substr(Pos + 1);
  return S.substr(0, S.find_first_of("\r\n"));
}

VecString split( const char* chars, StringRef str )
{
  VecString vs;

  String::size_type n0 = 0;
  String::size_type n1 = str.find_first_of( chars, 0 );
  vs.push_back( str.substr( n0, n1 ) );

  while( n1 != String::npos )
  {
    n0 = n1+1;
    n1 = str.find_first_of( chars, n0 );
    if( n1 != String::npos ) vs.push_back( str.substr( n0, n1-n0 ) );
    else vs.push_back( str.substr( n0 ) );
  }

  return vs;
}

// Primary pass pipeline description parsing routine.
// FIXME: Should this routine accept a TargetMachine or require the caller to
// pre-populate the analysis managers with target-specific stuff?
bool PassBuilder::parsePassPipeline(ModulePassManager &MPM,
                                    StringRef PipelineText, bool VerifyEachPass,
                                    bool DebugLogging) {
  // By default, try to parse the pipeline as-if it were within an implicit
  // 'module(...)' pass pipeline. If this will parse at all, it needs to
  // consume the entire string.
  if (parseModulePassPipeline(MPM, PipelineText, VerifyEachPass, DebugLogging))
    return PipelineText.empty();

  // This isn't parsable as a module pipeline, look for the end of a pass name
  // and directly drop down to that layer.
  StringRef FirstName =
      PipelineText.substr(0, PipelineText.find_first_of(",)"));
  assert(!isModulePassName(FirstName) &&
         "Already handled all module pipeline options.");

  // If this looks like a CGSCC pass, parse the whole thing as a CGSCC
  // pipeline.
  if (PipelineText.startswith("cgscc(") || isCGSCCPassName(FirstName)) {
    CGSCCPassManager CGPM(DebugLogging);
    if (!parseCGSCCPassPipeline(CGPM, PipelineText, VerifyEachPass,
                                DebugLogging) ||
        !PipelineText.empty())
      return false;
    MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(CGPM)));
    return true;
  }

  // Similarly, if this looks like a Function pass, parse the whole thing as
  // a Function pipelien.
  if (PipelineText.startswith("function(") || isFunctionPassName(FirstName)) {
    FunctionPassManager FPM(DebugLogging);
    if (!parseFunctionPassPipeline(FPM, PipelineText, VerifyEachPass,
                                   DebugLogging) ||
        !PipelineText.empty())
      return false;
    MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
    return true;
  }

  // If this looks like a Loop pass, parse the whole thing as a Loop pipeline.
  if (PipelineText.startswith("loop(") || isLoopPassName(FirstName)) {
    LoopPassManager LPM(DebugLogging);
    if (!parseLoopPassPipeline(LPM, PipelineText, VerifyEachPass,
                               DebugLogging) ||
        !PipelineText.empty())
      return false;
    FunctionPassManager FPM(DebugLogging);
    FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
    MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
    return true;
  }


  return false;
}

void Value::setNameImpl(const Twine &NewName) {
  // Fast-path: LLVMContext can be set to strip out non-GlobalValue names
  if (getContext().shouldDiscardValueNames() && !isa<GlobalValue>(this))
    return;

  // Fast path for common IRBuilder case of setName("") when there is no name.
  if (NewName.isTriviallyEmpty() && !hasName())
    return;

  SmallString<256> NameData;
  StringRef NameRef = NewName.toStringRef(NameData);
  assert(NameRef.find_first_of(0) == StringRef::npos &&
         "Null bytes are not allowed in names");

  // Name isn't changing?
  if (getName() == NameRef)
    return;

  assert(!getType()->isVoidTy() && "Cannot assign a name to void values!");

  // Get the symbol table to update for this object.
  ValueSymbolTable *ST;
  if (getSymTab(this, ST))
    return;  // Cannot set a name on this value (e.g. constant).

  if (!ST) { // No symbol table to update?  Just do the change.
    if (NameRef.empty()) {
      // Free the name for this value.
      destroyValueName();
      return;
    }

    // NOTE: Could optimize for the case the name is shrinking to not deallocate
    // then reallocated.
    destroyValueName();

    // Create the new name.
    setValueName(ValueName::Create(NameRef));
    getValueName()->setValue(this);
    return;
  }

  // NOTE: Could optimize for the case the name is shrinking to not deallocate
  // then reallocated.
  if (hasName()) {
    // Remove old name.
    ST->removeValueName(getValueName());
    destroyValueName();

    if (NameRef.empty())
      return;
  }

  // Name is changing to something new.
  setValueName(ST->createValueName(NameRef, this));
}

static SourceLoc findEndOfLine(SourceManager &SM, SourceLoc loc,
                               unsigned bufferID) {
  CharSourceRange entireBuffer = SM.getRangeForBuffer(bufferID);
  CharSourceRange rangeFromLoc{SM, loc, entireBuffer.getEnd()};
  StringRef textFromLoc = SM.extractText(rangeFromLoc);
  size_t newlineOffset = textFromLoc.find_first_of({"\r\n\0", 3});
  if (newlineOffset == StringRef::npos)
    return entireBuffer.getEnd();
  return loc.getAdvancedLoc(newlineOffset);
}

/// \brief Guess the end-of-line sequence used in the given FileID. If the
/// sequence can't be guessed return an Unix-style newline.
static StringRef guessEOL(SourceManager &SM, FileID ID) {
  StringRef Content = SM.getBufferData(ID);
  StringRef Buffer = Content.substr(Content.find_first_of("\r\n"));

  return llvm::StringSwitch<StringRef>(Buffer)
      .StartsWith("\r\n", "\r\n")
      .StartsWith("\n\r", "\n\r")
      .StartsWith("\r", "\r")
      .Default("\n");
}

/// getToken - This function extracts one token from source, ignoring any
/// leading characters that appear in the Delimiters string, and ending the
/// token at any of the characters that appear in the Delimiters string.  If
/// there are no tokens in the source string, an empty string is returned.
/// The function returns a pair containing the extracted token and the
/// remaining tail string.
std::pair<StringRef, StringRef> llvm::getToken(StringRef Source,
        StringRef Delimiters) {
    // Figure out where the token starts.
    StringRef::size_type Start = Source.find_first_not_of(Delimiters);

    // Find the next occurrence of the delimiter.
    StringRef::size_type End = Source.find_first_of(Delimiters, Start);

    return std::make_pair(Source.slice(Start, End), Source.substr(End));
}

static std::string QuoteProgramPathIfNeeded(StringRef Command) {
  if (Command.find_first_of(' ') == StringRef::npos)
    return Command;
  else {
    std::string ret;
    ret.reserve(Command.size() + 3);
    ret.push_back('"');
    ret.append(Command.begin(), Command.end());
    ret.push_back('"');
    return ret;
  }
}

bool PassBuilder::parseFunctionPassPipeline(FunctionPassManager &FPM,
                                            StringRef &PipelineText,
                                            bool VerifyEachPass,
                                            bool DebugLogging) {
  for (;;) {
    // Parse nested pass managers by recursing.
    if (PipelineText.startswith("function(")) {
      FunctionPassManager NestedFPM(DebugLogging);

      // Parse the inner pipeline inte the nested manager.
      PipelineText = PipelineText.substr(strlen("function("));
      if (!parseFunctionPassPipeline(NestedFPM, PipelineText, VerifyEachPass,
                                     DebugLogging) ||
          PipelineText.empty())
        return false;
      assert(PipelineText[0] == ')');
      PipelineText = PipelineText.substr(1);

      // Add the nested pass manager with the appropriate adaptor.
      FPM.addPass(std::move(NestedFPM));
    } else if (PipelineText.startswith("loop(")) {
      LoopPassManager NestedLPM(DebugLogging);

      // Parse the inner pipeline inte the nested manager.
      PipelineText = PipelineText.substr(strlen("loop("));
      if (!parseLoopPassPipeline(NestedLPM, PipelineText, VerifyEachPass,
                                 DebugLogging) ||
          PipelineText.empty())
        return false;
      assert(PipelineText[0] == ')');
      PipelineText = PipelineText.substr(1);

      // Add the nested pass manager with the appropriate adaptor.
      FPM.addPass(createFunctionToLoopPassAdaptor(std::move(NestedLPM)));
    } else {
      // Otherwise try to parse a pass name.
      size_t End = PipelineText.find_first_of(",)");
      if (!parseFunctionPassName(FPM, PipelineText.substr(0, End)))
        return false;
      if (VerifyEachPass)
        FPM.addPass(VerifierPass());

      PipelineText = PipelineText.substr(End);
    }

    if (PipelineText.empty() || PipelineText[0] == ')')
      return true;

    assert(PipelineText[0] == ',');
    PipelineText = PipelineText.substr(1);
  }
}

static bool parseCGSCCPassPipeline(CGSCCPassManager &CGPM,
                                   StringRef &PipelineText, bool VerifyEachPass,
                                   bool DebugLogging) {
  for (;;) {
    // Parse nested pass managers by recursing.
    if (PipelineText.startswith("cgscc(")) {
      CGSCCPassManager NestedCGPM(DebugLogging);

      // Parse the inner pipeline into the nested manager.
      PipelineText = PipelineText.substr(strlen("cgscc("));
      if (!parseCGSCCPassPipeline(NestedCGPM, PipelineText, VerifyEachPass,
                                  DebugLogging) ||
          PipelineText.empty())
        return false;
      assert(PipelineText[0] == ')');
      PipelineText = PipelineText.substr(1);

      // Add the nested pass manager with the appropriate adaptor.
      CGPM.addPass(std::move(NestedCGPM));
    } else if (PipelineText.startswith("function(")) {
      FunctionPassManager NestedFPM(DebugLogging);

      // Parse the inner pipeline inte the nested manager.
      PipelineText = PipelineText.substr(strlen("function("));
      if (!parseFunctionPassPipeline(NestedFPM, PipelineText, VerifyEachPass,
                                     DebugLogging) ||
          PipelineText.empty())
        return false;
      assert(PipelineText[0] == ')');
      PipelineText = PipelineText.substr(1);

      // Add the nested pass manager with the appropriate adaptor.
      CGPM.addPass(createCGSCCToFunctionPassAdaptor(std::move(NestedFPM)));
    } else {
      // Otherwise try to parse a pass name.
      size_t End = PipelineText.find_first_of(",)");
      if (!parseCGSCCPassName(CGPM, PipelineText.substr(0, End)))
        return false;
      // FIXME: No verifier support for CGSCC passes!

      PipelineText = PipelineText.substr(End);
    }

    if (PipelineText.empty() || PipelineText[0] == ')')
      return true;

    assert(PipelineText[0] == ',');
    PipelineText = PipelineText.substr(1);
  }
}

static bool parseModulePassPipeline(ModulePassManager &MPM,
                                    StringRef &PipelineText,
                                    bool VerifyEachPass) {
  for (;;) {
    // Parse nested pass managers by recursing.
    if (PipelineText.startswith("module(")) {
      ModulePassManager NestedMPM;

      // Parse the inner pipeline into the nested manager.
      PipelineText = PipelineText.substr(strlen("module("));
      if (!parseModulePassPipeline(NestedMPM, PipelineText, VerifyEachPass) ||
          PipelineText.empty())
        return false;
      assert(PipelineText[0] == ')');
      PipelineText = PipelineText.substr(1);

      // Now add the nested manager as a module pass.
      MPM.addPass(std::move(NestedMPM));
    } else if (PipelineText.startswith("function(")) {
      FunctionPassManager NestedFPM;

      // Parse the inner pipeline inte the nested manager.
      PipelineText = PipelineText.substr(strlen("function("));
      if (!parseFunctionPassPipeline(NestedFPM, PipelineText, VerifyEachPass) ||
          PipelineText.empty())
        return false;
      assert(PipelineText[0] == ')');
      PipelineText = PipelineText.substr(1);

      // Add the nested pass manager with the appropriate adaptor.
      MPM.addPass(createModuleToFunctionPassAdaptor(std::move(NestedFPM)));
    } else {
      // Otherwise try to parse a pass name.
      size_t End = PipelineText.find_first_of(",)");
      if (!parseModulePassName(MPM, PipelineText.substr(0, End)))
        return false;
      if (VerifyEachPass)
        MPM.addPass(VerifierPass());

      PipelineText = PipelineText.substr(End);
    }

    if (PipelineText.empty() || PipelineText[0] == ')')
      return true;

    assert(PipelineText[0] == ',');
    PipelineText = PipelineText.substr(1);
  }
}