llvm-project/llvm/lib/DebugInfo/PDB/Raw/NameMapBuilder.cpp

109 lines
3.6 KiB
C++

//===- NameMapBuilder.cpp - PDB Name Map Builder ----------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/STLExtras.h"
#include "llvm/DebugInfo/MSF/StreamWriter.h"
#include "llvm/DebugInfo/PDB/Raw/NameMap.h"
#include "llvm/DebugInfo/PDB/Raw/NameMapBuilder.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/Error.h"
#include <algorithm>
#include <cstdint>
using namespace llvm;
using namespace llvm::pdb;
NameMapBuilder::NameMapBuilder() = default;
void NameMapBuilder::addMapping(StringRef Name, uint32_t Mapping) {
StringDataBytes += Name.size() + 1;
Map.insert({Name, Mapping});
}
Expected<std::unique_ptr<NameMap>> NameMapBuilder::build() {
auto Result = llvm::make_unique<NameMap>();
Result->Mapping = Map;
return std::move(Result);
}
uint32_t NameMapBuilder::calculateSerializedLength() const {
uint32_t TotalLength = 0;
TotalLength += sizeof(support::ulittle32_t); // StringDataBytes value
TotalLength += StringDataBytes; // actual string data
TotalLength += sizeof(support::ulittle32_t); // Hash Size
TotalLength += sizeof(support::ulittle32_t); // Max Number of Strings
TotalLength += sizeof(support::ulittle32_t); // Num Present Words
// One bitmask word for each present entry
TotalLength += Map.size() * sizeof(support::ulittle32_t);
TotalLength += sizeof(support::ulittle32_t); // Num Deleted Words
// For each present word, which we are treating as equivalent to the number of
// entries in the table, we have a pair of integers. An offset into the
// string data, and a corresponding stream number.
TotalLength += Map.size() * 2 * sizeof(support::ulittle32_t);
return TotalLength;
}
Error NameMapBuilder::commit(msf::StreamWriter &Writer) const {
// The first field is the number of bytes of string data. So add
// up the length of all strings plus a null terminator for each
// one.
uint32_t NumBytes = 0;
for (auto B = Map.begin(), E = Map.end(); B != E; ++B) {
NumBytes += B->getKeyLength() + 1;
}
if (auto EC = Writer.writeInteger(NumBytes)) // Number of bytes of string data
return EC;
// Now all of the string data itself.
for (auto B = Map.begin(), E = Map.end(); B != E; ++B) {
if (auto EC = Writer.writeZeroString(B->getKey()))
return EC;
}
if (auto EC = Writer.writeInteger(Map.size())) // Hash Size
return EC;
if (auto EC = Writer.writeInteger(Map.size())) // Max Number of Strings
return EC;
if (auto EC = Writer.writeInteger(Map.size())) // Num Present Words
return EC;
// For each entry in the mapping, write a bit mask which represents a bucket
// to store it in. We don't use this, so the value we write isn't important
// to us, it just has to be there.
for (auto B = Map.begin(), E = Map.end(); B != E; ++B) {
if (auto EC = Writer.writeInteger(1U))
return EC;
}
if (auto EC = Writer.writeInteger(0U)) // Num Deleted Words
return EC;
// Mappings of each word.
uint32_t OffsetSoFar = 0;
for (auto B = Map.begin(), E = Map.end(); B != E; ++B) {
// This is a list of key value pairs where the key is the offset into the
// strings buffer, and the value is a stream number. Write each pair.
if (auto EC = Writer.writeInteger(OffsetSoFar))
return EC;
if (auto EC = Writer.writeInteger(B->second))
return EC;
OffsetSoFar += B->getKeyLength() + 1;
}
return Error::success();
}