llvm/lib/DebugInfo/PDB/Raw/ModInfo.cpp

//===- ModInfo.cpp - PDB module information -------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "llvm/DebugInfo/PDB/Raw/ModInfo.h"

#include "llvm/DebugInfo/CodeView/StreamReader.h"
#include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
#include "llvm/Support/Endian.h"

using namespace llvm;
using namespace llvm::pdb;
using namespace llvm::support;

namespace {

struct SCBytes {
  ulittle16_t Section;
  char Padding1[2];
  little32_t Offset;
  little32_t Size;
  ulittle32_t Characteristics;
  ulittle16_t ModuleIndex;
  char Padding2[2];
  ulittle32_t DataCrc;
  ulittle32_t RelocCrc;
};

// struct Flags {
//  uint16_t fWritten : 1;   // True if ModInfo is dirty
//  uint16_t fECEnabled : 1; // Is EC symbolic info present?  (What is EC?)
//  uint16_t unused : 6;     // Reserved
//  uint16_t iTSM : 8;       // Type Server Index for this module
//};
const uint16_t HasECFlagMask = 0x2;

const uint16_t TypeServerIndexMask = 0xFF00;
const uint16_t TypeServerIndexShift = 8;
}

struct ModInfo::FileLayout {
  ulittle32_t Mod;           // Currently opened module.  This field is a
                             // pointer in the reference implementation, but
                             // that won't work on 64-bit systems, and anyway
                             // it doesn't make sense to read a pointer from a
                             // file.  For now it is unused, so just ignore it.
  SCBytes SC;                // First section contribution of this module.
  ulittle16_t Flags;         // See Flags definition.
  ulittle16_t ModDiStream;   // Stream Number of module debug info
  ulittle32_t SymBytes;      // Size of local symbol debug info in above stream
  ulittle32_t LineBytes;     // Size of line number debug info in above stream
  ulittle32_t C13Bytes;      // Size of C13 line number info in above stream
  ulittle16_t NumFiles;      // Number of files contributing to this module
  char Padding1[2];          // Padding so the next field is 4-byte aligned.
  ulittle32_t FileNameOffs;  // array of [0..NumFiles) DBI name buffer offsets.
                             // This field is a pointer in the reference
                             // implementation, but as with `Mod`, we ignore it
                             // for now since it is unused.
  ulittle32_t SrcFileNameNI; // Name Index for src file name
  ulittle32_t PdbFilePathNI; // Name Index for path to compiler PDB
                             // Null terminated Module name
                             // Null terminated Obj File Name
};

ModInfo::ModInfo() : Layout(nullptr) {}

ModInfo::ModInfo(codeview::StreamRef Stream) : Layout(nullptr) {
  codeview::StreamReader Reader(Stream);
  if (auto EC = Reader.readObject(Layout)) {
    consumeError(std::move(EC));
    return;
  }
  if (auto EC = Reader.readZeroString(ModuleName)) {
    consumeError(std::move(EC));
    return;
  }
  if (auto EC = Reader.readZeroString(ObjFileName)) {
    consumeError(std::move(EC));
    return;
  }
}

ModInfo::ModInfo(const ModInfo &Info)
    : ModuleName(Info.ModuleName), ObjFileName(Info.ObjFileName),
      Layout(Info.Layout) {}

ModInfo::~ModInfo() {}

bool ModInfo::hasECInfo() const { return (Layout->Flags & HasECFlagMask) != 0; }

uint16_t ModInfo::getTypeServerIndex() const {
  return (Layout->Flags & TypeServerIndexMask) >> TypeServerIndexShift;
}

uint16_t ModInfo::getModuleStreamIndex() const { return Layout->ModDiStream; }

uint32_t ModInfo::getSymbolDebugInfoByteSize() const {
  return Layout->SymBytes;
}

uint32_t ModInfo::getLineInfoByteSize() const { return Layout->LineBytes; }

uint32_t ModInfo::getC13LineInfoByteSize() const { return Layout->C13Bytes; }

uint32_t ModInfo::getNumberOfFiles() const { return Layout->NumFiles; }

uint32_t ModInfo::getSourceFileNameIndex() const {
  return Layout->SrcFileNameNI;
}

uint32_t ModInfo::getPdbFilePathNameIndex() const {
  return Layout->PdbFilePathNI;
}

StringRef ModInfo::getModuleName() const { return ModuleName; }

StringRef ModInfo::getObjFileName() const { return ObjFileName; }

uint32_t ModInfo::getRecordLength() const {
  uint32_t M = ModuleName.str().size() + 1;
  uint32_t O = ObjFileName.str().size() + 1;
  uint32_t Size = sizeof(FileLayout) + M + O;
  Size = llvm::alignTo(Size, 4);
  return Size;
}