C++ StringRef::startswith方法代码示例

static bool doesNoDiscardMacroExist(ASTContext &Context,
                                    const llvm::StringRef &MacroId) {
  // Don't check for the Macro existence if we are using an attribute
  // either a C++17 standard attribute or pre C++17 syntax
  if (MacroId.startswith("[[") || MacroId.startswith("__attribute__"))
    return true;

  // Otherwise look up the macro name in the context to see if its defined.
  return Context.Idents.get(MacroId).hasMacroDefinition();
}

lldb::SymbolType
ObjectFile::GetSymbolTypeFromName(llvm::StringRef name,
                                  lldb::SymbolType symbol_type_hint) {
  if (!name.empty()) {
    if (name.startswith("_T")) {
      // Swift
      if (name.startswith("_TM"))
        return lldb::eSymbolTypeMetadata;
      if (name.startswith("_TWvd"))
        return lldb::eSymbolTypeIVarOffset;
    } else if (name.startswith("_OBJC_")) {
      // ObjC
      if (name.startswith("_OBJC_CLASS_$_"))
        return lldb::eSymbolTypeObjCClass;
      if (name.startswith("_OBJC_METACLASS_$_"))
        return lldb::eSymbolTypeObjCMetaClass;
      if (name.startswith("_OBJC_IVAR_$_"))
        return lldb::eSymbolTypeObjCIVar;
    } else if (name.startswith(".objc_class_name_")) {
      // ObjC v1
      return lldb::eSymbolTypeObjCClass;
    }
  }
  return symbol_type_hint;
}

std::string Context::getThunkTarget(llvm::StringRef MangledName) {
  if (!isThunkSymbol(MangledName))
    return std::string();

  if (isMangledName(MangledName)) {
    // The targets of those thunks not derivable from the mangling.
    if (MangledName.endswith("TR") ||
        MangledName.endswith("Tr") ||
        MangledName.endswith("TW") )
      return std::string();

    if (MangledName.endswith("fC")) {
      std::string target = MangledName.str();
      target[target.size() - 1] = 'c';
      return target;
    }

    return MangledName.substr(0, MangledName.size() - 2).str();
  }
  // Old mangling.
  assert(MangledName.startswith("_T"));
  StringRef Remaining = MangledName.substr(2);
  if (Remaining.startswith("PA_"))
    return Remaining.substr(3).str();
  if (Remaining.startswith("PAo_"))
    return Remaining.substr(4).str();
  assert(Remaining.startswith("To") || Remaining.startswith("TO"));
  return std::string("_T") + Remaining.substr(2).str();
}

// Parses the contents of version.txt in an CUDA installation.  It should
// contain one line of the from e.g. "CUDA Version 7.5.2".
static CudaVersion ParseCudaVersionFile(llvm::StringRef V) {
  if (!V.startswith("CUDA Version "))
    return CudaVersion::UNKNOWN;
  V = V.substr(strlen("CUDA Version "));
  int Major = -1, Minor = -1;
  auto First = V.split('.');
  auto Second = First.second.split('.');
  if (First.first.getAsInteger(10, Major) ||
      Second.first.getAsInteger(10, Minor))
    return CudaVersion::UNKNOWN;

  if (Major == 7 && Minor == 0) {
    // This doesn't appear to ever happen -- version.txt doesn't exist in the
    // CUDA 7 installs I've seen.  But no harm in checking.
    return CudaVersion::CUDA_70;
  }
  if (Major == 7 && Minor == 5)
    return CudaVersion::CUDA_75;
  if (Major == 8 && Minor == 0)
    return CudaVersion::CUDA_80;
  if (Major == 9 && Minor == 0)
    return CudaVersion::CUDA_90;
  if (Major == 9 && Minor == 1)
    return CudaVersion::CUDA_91;
  return CudaVersion::UNKNOWN;
}

URI::URI(llvm::StringRef Scheme, llvm::StringRef Authority,
         llvm::StringRef Body)
    : Scheme(Scheme), Authority(Authority), Body(Body) {
  assert(!Scheme.empty());
  assert((Authority.empty() || Body.startswith("/")) &&
         "URI body must start with '/' when authority is present.");
}

static void demangle(llvm::raw_ostream &os, llvm::StringRef name,
                     const swift::Demangle::DemangleOptions &options) {
  bool hadLeadingUnderscore = false;
  if (name.startswith("__")) {
    hadLeadingUnderscore = true;
    name = name.substr(1);
  }
  swift::Demangle::NodePointer pointer =
      swift::demangle_wrappers::demangleSymbolAsNode(name);
  if (ExpandMode || TreeOnly) {
    llvm::outs() << "Demangling for " << name << '\n';
    swift::demangle_wrappers::NodeDumper(pointer).print(llvm::outs());
  }
  if (RemangleMode) {
    if (hadLeadingUnderscore) llvm::outs() << '_';
    // Just reprint the original mangled name if it didn't demangle.
    // This makes it easier to share the same database between the
    // mangling and demangling tests.
    if (!pointer) {
      llvm::outs() << name;
    } else {
      llvm::outs() << swift::Demangle::mangleNode(pointer);
    }
    return;
  }
  if (!TreeOnly) {
    std::string string = swift::Demangle::nodeToString(pointer, options);
    if (!CompactMode)
      llvm::outs() << name << " ---> ";
    llvm::outs() << (string.empty() ? name : llvm::StringRef(string));
  }
}

llvm::Optional<TextEdit>
IncludeInserter::insert(llvm::StringRef VerbatimHeader) const {
  llvm::Optional<TextEdit> Edit = None;
  if (auto Insertion = Inserter.insert(VerbatimHeader.trim("\"<>"),
                                       VerbatimHeader.startswith("<")))
    Edit = replacementToEdit(Code, *Insertion);
  return Edit;
}

  void AutoloadCallback::report(clang::SourceLocation l, llvm::StringRef name,
                                llvm::StringRef header) {
    Sema& sema= m_Interpreter->getSema();

    unsigned id
      = sema.getDiagnostics().getCustomDiagID (DiagnosticsEngine::Level::Warning,
                                                 "Note: '%0' can be found in %1");
/*    unsigned idn //TODO: To be enabled after we have a way to get the full path
      = sema.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Level::Note,
                                                "Type : %0 , Full Path: %1")*/;

    if (header.startswith(llvm::StringRef(annoTag, lenAnnoTag)))
      sema.Diags.Report(l, id) << name << header.drop_front(lenAnnoTag);

  }

static bool IsValidBasename(const llvm::StringRef &basename) {
  // Check that the basename matches with the following regular expression or is
  // an operator name:
  // "^~?([A-Za-z_][A-Za-z_0-9]*)(<.*>)?$"
  // We are using a hand written implementation because it is significantly more
  // efficient then
  // using the general purpose regular expression library.
  size_t idx = 0;
  if (basename.size() > 0 && basename[0] == '~')
    idx = 1;

  if (basename.size() <= idx)
    return false; // Empty string or "~"

  if (!std::isalpha(basename[idx]) && basename[idx] != '_')
    return false; // First charater (after removing the possible '~'') isn't in
                  // [A-Za-z_]

  // Read all characters matching [A-Za-z_0-9]
  ++idx;
  while (idx < basename.size()) {
    if (!std::isalnum(basename[idx]) && basename[idx] != '_')
      break;
    ++idx;
  }

  // We processed all characters. It is a vaild basename.
  if (idx == basename.size())
    return true;

  // Check for basename with template arguments
  // TODO: Improve the quality of the validation with validating the template
  // arguments
  if (basename[idx] == '<' && basename.back() == '>')
    return true;

  // Check if the basename is a vaild C++ operator name
  if (!basename.startswith("operator"))
    return false;

  static RegularExpression g_operator_regex(
      llvm::StringRef("^(operator)( "
                      "?)([A-Za-z_][A-Za-z_0-9]*|\\(\\)|"
                      "\\[\\]|[\\^<>=!\\/"
                      "*+-]+)(<.*>)?(\\[\\])?$"));
  std::string basename_str(basename.str());
  return g_operator_regex.Execute(basename_str, nullptr);
}

bool MocPPCallbacks::FileNotFound(llvm::StringRef FileName, llvm::SmallVectorImpl< char >& RecoveryPath) {
    if (FileName.endswith(".moc") || FileName.endswith("_moc.cpp") || FileName.startswith("moc_")) {
        if (!PP.GetSuppressIncludeNotFoundError()) {
            PP.SetSuppressIncludeNotFoundError(true);
            IncludeNotFoundSupressed = true;
        }
    } else {
        if (IncludeNotFoundSupressed) {
            PP.SetSuppressIncludeNotFoundError(false);
            IncludeNotFoundSupressed = false;
        } else {
            ShouldWarnHeaderNotFound = true;
        }
    }
    return false;
}

bool Context::isThunkSymbol(llvm::StringRef MangledName) {
  if (isMangledName(MangledName)) {
    // First do a quick check
    if (MangledName.endswith("TA") ||  // partial application forwarder
        MangledName.endswith("Ta") ||  // ObjC partial application forwarder
        MangledName.endswith("To") ||  // swift-as-ObjC thunk
        MangledName.endswith("TO") ||  // ObjC-as-swift thunk
        MangledName.endswith("TR") ||  // reabstraction thunk helper function
        MangledName.endswith("Tr") ||  // reabstraction thunk
        MangledName.endswith("TW") ||  // protocol witness thunk
        MangledName.endswith("fC")) {  // allocating constructor

      // To avoid false positives, we need to fully demangle the symbol.
      NodePointer Nd = D->demangleSymbol(MangledName);
      if (!Nd || Nd->getKind() != Node::Kind::Global ||
          Nd->getNumChildren() == 0)
        return false;

      switch (Nd->getFirstChild()->getKind()) {
        case Node::Kind::ObjCAttribute:
        case Node::Kind::NonObjCAttribute:
        case Node::Kind::PartialApplyObjCForwarder:
        case Node::Kind::PartialApplyForwarder:
        case Node::Kind::ReabstractionThunkHelper:
        case Node::Kind::ReabstractionThunk:
        case Node::Kind::ProtocolWitness:
        case Node::Kind::Allocator:
          return true;
        default:
          break;
      }
    }
    return false;
  }

  if (MangledName.startswith("_T")) {
    // Old mangling.
    StringRef Remaining = MangledName.substr(2);
    if (Remaining.startswith("To") ||   // swift-as-ObjC thunk
        Remaining.startswith("TO") ||   // ObjC-as-swift thunk
        Remaining.startswith("PA_") ||  // partial application forwarder
        Remaining.startswith("PAo_")) { // ObjC partial application forwarder
      return true;
    }
  }
  return false;
}

bool cocoa::isRefType(QualType RetTy, llvm::StringRef Prefix,
                      llvm::StringRef Name) {
  // Recursively walk the typedef stack, allowing typedefs of reference types.
  while (const TypedefType *TD = dyn_cast<TypedefType>(RetTy.getTypePtr())) {
    llvm::StringRef TDName = TD->getDecl()->getIdentifier()->getName();
    if (TDName.startswith(Prefix) && TDName.endswith("Ref"))
      return true;
    
    RetTy = TD->getDecl()->getUnderlyingType();
  }
  
  if (Name.empty())
    return false;
  
  // Is the type void*?
  const PointerType* PT = RetTy->getAs<PointerType>();
  if (!(PT->getPointeeType().getUnqualifiedType()->isVoidType()))
    return false;
  
  // Does the name start with the prefix?
  return Name.startswith(Prefix);
}

  std::string
  DynamicLibraryManager::lookupLibrary(llvm::StringRef libStem) const {
    llvm::SmallString<128> Absolute(libStem);
    llvm::sys::fs::make_absolute(Absolute);
    bool isAbsolute = libStem == Absolute;

    // If it is an absolute path, don't try iterate over the paths.
    if (isAbsolute) {
      if (isSharedLib(libStem))
        return normalizePath(libStem);
      else
        return "";
    }

    std::string foundName = lookupLibMaybeAddExt(libStem);
    if (foundName.empty() && !libStem.startswith("lib")) {
      // try with "lib" prefix:
      foundName = lookupLibMaybeAddExt("lib" + libStem.str());
    }

    if (isSharedLib(foundName))
      return normalizePath(foundName);
    return "";
  }

void XCTMigrator::migrateInclude(llvm::StringRef Filename,
                                 CharSourceRange FilenameRange,
                                 SourceLocation HashLoc, bool isAngled) {
  StringRef Parent = "SenTestingKit/";
  if (!Filename.startswith(Parent))
    return;
  if (isFromSenTestInclude(HashLoc))
    return;

  edit::Commit commit(Editor);
  StringRef HeaderName = Filename.substr(Parent.size());
  llvm::StringMap<llvm::StringRef>::iterator I = IncludesMap.find(HeaderName);
  if (I == IncludesMap.end() || I->second.empty()) {
    commit.remove(CharSourceRange::getCharRange(HashLoc,FilenameRange.getEnd()));
  } else {
    SmallString<128> NewInclude;
    NewInclude.push_back(isAngled ? '<' : '"');
    NewInclude += "XCTest/";
    NewInclude += I->second;
    NewInclude.push_back(isAngled ? '>' : '"');
    commit.replace(FilenameRange, NewInclude.str());
  }
  Editor.commit(commit);
}

std::vector<find_all_symbols::SymbolInfo>
SymbolIndexManager::search(llvm::StringRef Identifier,
                           bool IsNestedSearch) const {
  // The identifier may be fully qualified, so split it and get all the context
  // names.
  llvm::SmallVector<llvm::StringRef, 8> Names;
  Identifier.split(Names, "::");

  bool IsFullyQualified = false;
  if (Identifier.startswith("::")) {
    Names.erase(Names.begin()); // Drop first (empty) element.
    IsFullyQualified = true;
  }

  // As long as we don't find a result keep stripping name parts from the end.
  // This is to support nested classes which aren't recorded in the database.
  // Eventually we will either hit a class (namespaces aren't in the database
  // either) and can report that result.
  bool TookPrefix = false;
  std::vector<clang::find_all_symbols::SymbolInfo> MatchedSymbols;
  do {
    std::vector<clang::find_all_symbols::SymbolInfo> Symbols;
    for (const auto &DB : SymbolIndices) {
      auto Res = DB->search(Names.back().str());
      Symbols.insert(Symbols.end(), Res.begin(), Res.end());
    }

    DEBUG(llvm::dbgs() << "Searching " << Names.back() << "... got "
                       << Symbols.size() << " results...\n");

    for (const auto &Symbol : Symbols) {
      // Match the identifier name without qualifier.
      if (Symbol.getName() == Names.back()) {
        bool IsMatched = true;
        auto SymbolContext = Symbol.getContexts().begin();
        auto IdentiferContext = Names.rbegin() + 1; // Skip identifier name.
        // Match the remaining context names.
        while (IdentiferContext != Names.rend() &&
               SymbolContext != Symbol.getContexts().end()) {
          if (SymbolContext->second == *IdentiferContext) {
            ++IdentiferContext;
            ++SymbolContext;
          } else if (SymbolContext->first ==
                     find_all_symbols::SymbolInfo::ContextType::EnumDecl) {
            // Skip non-scoped enum context.
            ++SymbolContext;
          } else {
            IsMatched = false;
            break;
          }
        }

        // If the name was qualified we only want to add results if we evaluated
        // all contexts.
        if (IsFullyQualified)
          IsMatched &= (SymbolContext == Symbol.getContexts().end());

        // FIXME: Support full match. At this point, we only find symbols in
        // database which end with the same contexts with the identifier.
        if (IsMatched && IdentiferContext == Names.rend()) {
          // If we're in a situation where we took a prefix but the thing we
          // found couldn't possibly have a nested member ignore it.
          if (TookPrefix &&
              (Symbol.getSymbolKind() == SymbolInfo::SymbolKind::Function ||
               Symbol.getSymbolKind() == SymbolInfo::SymbolKind::Variable ||
               Symbol.getSymbolKind() ==
                   SymbolInfo::SymbolKind::EnumConstantDecl ||
               Symbol.getSymbolKind() == SymbolInfo::SymbolKind::Macro))
            continue;

          MatchedSymbols.push_back(Symbol);
        }
      }
    }
    Names.pop_back();
    TookPrefix = true;
  } while (MatchedSymbols.empty() && !Names.empty() && IsNestedSearch);

  rankByPopularity(MatchedSymbols);
  return MatchedSymbols;
}