text: //===- DebugStringTableSubsection.cpp - CodeView String Table -------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  #include "llvm/DebugInfo/CodeView/DebugStringTableSubsection.h"
  #include "llvm/ADT/StringRef.h"
  #include "llvm/DebugInfo/CodeView/CodeView.h"
  #include "llvm/Support/BinaryStreamReader.h"
  #include "llvm/Support/BinaryStreamWriter.h"
  #include "llvm/Support/Error.h"
  #include <algorithm>
  #include <cassert>
  #include <cstdint>
  
  using namespace llvm;
  using namespace llvm::codeview;
  
  DebugStringTableSubsectionRef::DebugStringTableSubsectionRef()
      : DebugSubsectionRef(DebugSubsectionKind::StringTable) {}
  
  Error DebugStringTableSubsectionRef::initialize(BinaryStreamRef Contents) {
    Stream = Contents;
    return Error::success();
  }
  
  Error DebugStringTableSubsectionRef::initialize(BinaryStreamReader &Reader) {
    return Reader.readStreamRef(Stream);
  }
  
  Expected<StringRef>
  DebugStringTableSubsectionRef::getString(uint32_t Offset) const {
    BinaryStreamReader Reader(Stream);
    Reader.setOffset(Offset);
    StringRef Result;
    if (auto EC = Reader.readCString(Result))
      return std::move(EC);
    return Result;
  }
  
  DebugStringTableSubsection::DebugStringTableSubsection()
      : DebugSubsection(DebugSubsectionKind::StringTable) {}
  
  uint32_t DebugStringTableSubsection::insert(StringRef S) {
    auto P = StringToId.insert({S, StringSize});
  
    // If a given string didn't exist in the string table, we want to increment
    // the string table size and insert it into the reverse lookup.
    if (P.second) {
      IdToString.insert({P.first->getValue(), P.first->getKey()});
      StringSize += S.size() + 1; // +1 for '\0'
    }
  
    return P.first->second;
  }
  
  uint32_t DebugStringTableSubsection::calculateSerializedSize() const {
    return StringSize;
  }
  
  Error DebugStringTableSubsection::commit(BinaryStreamWriter &Writer) const {
    uint32_t Begin = Writer.getOffset();
    uint32_t End = Begin + StringSize;
  
    // Write a null string at the beginning.
    if (auto EC = Writer.writeCString(StringRef()))
      return EC;
  
    for (auto &Pair : StringToId) {
      StringRef S = Pair.getKey();
      uint32_t Offset = Begin + Pair.getValue();
      Writer.setOffset(Offset);
      if (auto EC = Writer.writeCString(S))
        return EC;
      assert(Writer.getOffset() <= End);
    }
  
    Writer.setOffset(End);
    assert((End - Begin) == StringSize);
    return Error::success();
  }
  
  uint32_t DebugStringTableSubsection::size() const { return StringToId.size(); }
  
  std::vector<uint32_t> DebugStringTableSubsection::sortedIds() const {
    std::vector<uint32_t> Result;
    Result.reserve(IdToString.size());
    for (const auto &Entry : IdToString)
      Result.push_back(Entry.first);
    llvm::sort(Result.begin(), Result.end());
    return Result;
  }
  
  uint32_t DebugStringTableSubsection::getIdForString(StringRef S) const {
    auto Iter = StringToId.find(S);
    assert(Iter != StringToId.end());
    return Iter->second;
  }
  
  StringRef DebugStringTableSubsection::getStringForId(uint32_t Id) const {
    auto Iter = IdToString.find(Id);
    assert(Iter != IdToString.end());
    return Iter->second;
  }
  