//===- NativeSession.cpp - Native implementation of IPDBSession -*- C++ -*-===//
//
//                     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/Native/NativeSession.h"

#include "llvm/ADT/STLExtras.h"
#include "llvm/DebugInfo/CodeView/TypeIndex.h"
#include "llvm/DebugInfo/PDB/GenericError.h"
#include "llvm/DebugInfo/PDB/IPDBEnumChildren.h"
#include "llvm/DebugInfo/PDB/IPDBSourceFile.h"
#include "llvm/DebugInfo/PDB/Native/NativeBuiltinSymbol.h"
#include "llvm/DebugInfo/PDB/Native/NativeCompilandSymbol.h"
#include "llvm/DebugInfo/PDB/Native/NativeExeSymbol.h"
#include "llvm/DebugInfo/PDB/Native/PDBFile.h"
#include "llvm/DebugInfo/PDB/Native/RawError.h"
#include "llvm/DebugInfo/PDB/PDBSymbolCompiland.h"
#include "llvm/DebugInfo/PDB/PDBSymbolExe.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/BinaryByteStream.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/MemoryBuffer.h"

#include <algorithm>
#include <memory>
#include <utility>

using namespace llvm;
using namespace llvm::msf;
using namespace llvm::pdb;

namespace {
// Maps codeview::SimpleTypeKind of a built-in type to the parameters necessary
// to instantiate a NativeBuiltinSymbol for that type.
static const struct BuiltinTypeEntry {
  codeview::SimpleTypeKind Kind;
  PDB_BuiltinType Type;
  uint32_t Size;
} BuiltinTypes[] = {
    {codeview::SimpleTypeKind::Int32, PDB_BuiltinType::Int, 4},
    {codeview::SimpleTypeKind::UInt32, PDB_BuiltinType::UInt, 4},
    {codeview::SimpleTypeKind::UInt32Long, PDB_BuiltinType::UInt, 4},
    {codeview::SimpleTypeKind::UInt64Quad, PDB_BuiltinType::UInt, 8},
    {codeview::SimpleTypeKind::NarrowCharacter, PDB_BuiltinType::Char, 1},
    {codeview::SimpleTypeKind::SignedCharacter, PDB_BuiltinType::Char, 1},
    {codeview::SimpleTypeKind::UnsignedCharacter, PDB_BuiltinType::UInt, 1},
    {codeview::SimpleTypeKind::UInt16Short, PDB_BuiltinType::UInt, 2},
    {codeview::SimpleTypeKind::Boolean8, PDB_BuiltinType::Bool, 1}
    // This table can be grown as necessary, but these are the only types we've
    // needed so far.
};
} // namespace

NativeSession::NativeSession(std::unique_ptr<PDBFile> PdbFile,
                             std::unique_ptr<BumpPtrAllocator> Allocator)
    : Pdb(std::move(PdbFile)), Allocator(std::move(Allocator)) {}

NativeSession::~NativeSession() = default;

Error NativeSession::createFromPdb(StringRef Path,
                                   std::unique_ptr<IPDBSession> &Session) {
  ErrorOr<std::unique_ptr<MemoryBuffer>> ErrorOrBuffer =
      MemoryBuffer::getFileOrSTDIN(Path, /*FileSize=*/-1,
                                   /*RequiresNullTerminator=*/false);
  if (!ErrorOrBuffer)
    return make_error<GenericError>(generic_error_code::invalid_path);

  std::unique_ptr<MemoryBuffer> Buffer = std::move(*ErrorOrBuffer);
  auto Stream = llvm::make_unique<MemoryBufferByteStream>(
      std::move(Buffer), llvm::support::little);

  auto Allocator = llvm::make_unique<BumpPtrAllocator>();
  auto File = llvm::make_unique<PDBFile>(Path, std::move(Stream), *Allocator);
  if (auto EC = File->parseFileHeaders())
    return EC;
  if (auto EC = File->parseStreamData())
    return EC;

  Session =
      llvm::make_unique<NativeSession>(std::move(File), std::move(Allocator));

  return Error::success();
}

Error NativeSession::createFromExe(StringRef Path,
                                   std::unique_ptr<IPDBSession> &Session) {
  return make_error<RawError>(raw_error_code::feature_unsupported);
}

std::unique_ptr<PDBSymbolCompiland>
NativeSession::createCompilandSymbol(DbiModuleDescriptor MI) {
  const auto Id = static_cast<SymIndexId>(SymbolCache.size());
  SymbolCache.push_back(
      llvm::make_unique<NativeCompilandSymbol>(*this, Id, MI));
  return llvm::make_unique<PDBSymbolCompiland>(
      *this, std::unique_ptr<IPDBRawSymbol>(SymbolCache[Id]->clone()));
}

SymIndexId NativeSession::findSymbolByTypeIndex(codeview::TypeIndex Index) {
  // First see if it's already in our cache.
  const auto Entry = TypeIndexToSymbolId.find(Index);
  if (Entry != TypeIndexToSymbolId.end())
    return Entry->second;

  // Symbols for built-in types are created on the fly.
  if (Index.isSimple()) {
    // FIXME:  We will eventually need to handle pointers to other simple types,
    // which are still simple types in the world of CodeView TypeIndexes.
    if (Index.getSimpleMode() != codeview::SimpleTypeMode::Direct)
      return 0;
    const auto Kind = Index.getSimpleKind();
    const auto It =
        std::find_if(std::begin(BuiltinTypes), std::end(BuiltinTypes),
                     [Kind](const BuiltinTypeEntry &Builtin) {
                       return Builtin.Kind == Kind;
                     });
    if (It == std::end(BuiltinTypes))
      return 0;
    SymIndexId Id = SymbolCache.size();
    SymbolCache.emplace_back(
        llvm::make_unique<NativeBuiltinSymbol>(*this, Id, It->Type, It->Size));
    TypeIndexToSymbolId[Index] = Id;
    return Id;
  }

  // TODO:  Look up PDB type by type index

  return 0;
}

uint64_t NativeSession::getLoadAddress() const { return 0; }

void NativeSession::setLoadAddress(uint64_t Address) {}

std::unique_ptr<PDBSymbolExe> NativeSession::getGlobalScope() {
  const auto Id = static_cast<SymIndexId>(SymbolCache.size());
  SymbolCache.push_back(llvm::make_unique<NativeExeSymbol>(*this, Id));
  auto RawSymbol = SymbolCache[Id]->clone();
  auto PdbSymbol(PDBSymbol::create(*this, std::move(RawSymbol)));
  std::unique_ptr<PDBSymbolExe> ExeSymbol(
      static_cast<PDBSymbolExe *>(PdbSymbol.release()));
  return ExeSymbol;
}

std::unique_ptr<PDBSymbol>
NativeSession::getSymbolById(uint32_t SymbolId) const {
  // If the caller has a SymbolId, it'd better be in our SymbolCache.
  return SymbolId < SymbolCache.size()
             ? PDBSymbol::create(*this, SymbolCache[SymbolId]->clone())
             : nullptr;
}

std::unique_ptr<PDBSymbol>
NativeSession::findSymbolByAddress(uint64_t Address, PDB_SymType Type) const {
  return nullptr;
}

std::unique_ptr<IPDBEnumLineNumbers>
NativeSession::findLineNumbers(const PDBSymbolCompiland &Compiland,
                               const IPDBSourceFile &File) const {
  return nullptr;
}

std::unique_ptr<IPDBEnumLineNumbers>
NativeSession::findLineNumbersByAddress(uint64_t Address,
                                        uint32_t Length) const {
  return nullptr;
}

std::unique_ptr<IPDBEnumSourceFiles>
NativeSession::findSourceFiles(const PDBSymbolCompiland *Compiland,
                               StringRef Pattern,
                               PDB_NameSearchFlags Flags) const {
  return nullptr;
}

std::unique_ptr<IPDBSourceFile>
NativeSession::findOneSourceFile(const PDBSymbolCompiland *Compiland,
                                 StringRef Pattern,
                                 PDB_NameSearchFlags Flags) const {
  return nullptr;
}

std::unique_ptr<IPDBEnumChildren<PDBSymbolCompiland>>
NativeSession::findCompilandsForSourceFile(StringRef Pattern,
                                           PDB_NameSearchFlags Flags) const {
  return nullptr;
}

std::unique_ptr<PDBSymbolCompiland>
NativeSession::findOneCompilandForSourceFile(StringRef Pattern,
                                             PDB_NameSearchFlags Flags) const {
  return nullptr;
}

std::unique_ptr<IPDBEnumSourceFiles> NativeSession::getAllSourceFiles() const {
  return nullptr;
}

std::unique_ptr<IPDBEnumSourceFiles> NativeSession::getSourceFilesForCompiland(
    const PDBSymbolCompiland &Compiland) const {
  return nullptr;
}

std::unique_ptr<IPDBSourceFile>
NativeSession::getSourceFileById(uint32_t FileId) const {
  return nullptr;
}

std::unique_ptr<IPDBEnumDataStreams> NativeSession::getDebugStreams() const {
  return nullptr;
}