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//===--- TranslationUnit.cpp - Abstraction for Translation Units ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
// FIXME: This should eventually be moved out of the driver, or replaced
// with its eventual successor.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/TranslationUnit.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Basic/SourceManager.h"
#include "clang/AST/AST.h"
#include "llvm/Bitcode/Serialize.h"
#include "llvm/Bitcode/Deserialize.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/System/Path.h"
#include "llvm/ADT/OwningPtr.h"
#include <stdio.h>
using namespace clang;
enum { BasicMetadataBlock = 1,
ASTContextBlock = 2,
DeclsBlock = 3 };
TranslationUnit::~TranslationUnit() {
for (iterator I=begin(), E=end(); I!=E; ++I)
(*I)->Destroy(*Context);
if (OwnsMetaData && Context) {
// The ASTContext object has the sole references to the IdentifierTable
// Selectors, and the Target information. Go and delete them, since
// the TranslationUnit effectively owns them.
delete &(Context->Idents);
delete &(Context->Selectors);
delete &(Context->Target);
delete Context;
}
}
bool clang::EmitASTBitcodeFile(const TranslationUnit* TU,
const llvm::sys::Path& Filename) {
return TU ? EmitASTBitcodeFile(*TU, Filename) : false;
}
bool clang::EmitASTBitcodeFile(const TranslationUnit& TU,
const llvm::sys::Path& Filename) {
// Reserve 256K for bitstream buffer.
std::vector<unsigned char> Buffer;
Buffer.reserve(256*1024);
// Create bitstream.
llvm::BitstreamWriter Stream(Buffer);
// Emit the preamble.
Stream.Emit((unsigned)'B', 8);
Stream.Emit((unsigned)'C', 8);
Stream.Emit(0xC, 4);
Stream.Emit(0xF, 4);
Stream.Emit(0xE, 4);
Stream.Emit(0x0, 4);
{
// Create serializer. Placing it in its own scope assures any necessary
// finalization of bits to the buffer in the serializer's dstor.
llvm::Serializer Sezr(Stream);
// Emit the translation unit.
TU.Emit(Sezr);
}
// Write the bits to disk.
if (FILE* fp = fopen(Filename.c_str(),"wb")) {
fwrite((char*)&Buffer.front(), sizeof(char), Buffer.size(), fp);
fclose(fp);
return true;
}
return false;
}
void TranslationUnit::Emit(llvm::Serializer& Sezr) const {
// ===---------------------------------------------------===/
// Serialize the top-level decls.
// ===---------------------------------------------------===/
Sezr.EnterBlock(DeclsBlock);
// Only serialize the head of a decl chain. The ASTConsumer interfaces
// provides us with each top-level decl, including those nested in
// a decl chain, so we may be passed decls that are already serialized.
for (const_iterator I=begin(), E=end(); I!=E; ++I)
if (!Sezr.isRegistered(*I))
Sezr.EmitOwnedPtr(*I);
Sezr.ExitBlock();
// ===---------------------------------------------------===/
// Serialize the "Translation Unit" metadata.
// ===---------------------------------------------------===/
// Emit ASTContext.
Sezr.EnterBlock(ASTContextBlock);
Sezr.EmitOwnedPtr(Context);
Sezr.ExitBlock();
Sezr.EnterBlock(BasicMetadataBlock);
// Block for SourceManager, LangOptions, and Target. Allows easy skipping
// around to the block for the Selectors during deserialization.
Sezr.EnterBlock();
// Emit the SourceManager.
Sezr.Emit(Context->getSourceManager());
// Emit the LangOptions.
Sezr.Emit(LangOpts);
// Emit the Target.
Sezr.EmitPtr(&Context->Target);
Sezr.EmitCStr(Context->Target.getTargetTriple());
Sezr.ExitBlock(); // exit "BasicMetadataBlock"
// Emit the Selectors.
Sezr.Emit(Context->Selectors);
// Emit the Identifier Table.
Sezr.Emit(Context->Idents);
Sezr.ExitBlock(); // exit "ASTContextBlock"
}
TranslationUnit*
clang::ReadASTBitcodeFile(const llvm::sys::Path& Filename, FileManager& FMgr) {
// Create the memory buffer that contains the contents of the file.
llvm::OwningPtr<llvm::MemoryBuffer>
MBuffer(llvm::MemoryBuffer::getFile(Filename.c_str()));
if (!MBuffer) {
// FIXME: Provide diagnostic.
return NULL;
}
// Check if the file is of the proper length.
if (MBuffer->getBufferSize() & 0x3) {
// FIXME: Provide diagnostic: "Length should be a multiple of 4 bytes."
return NULL;
}
// Create the bitstream reader.
unsigned char *BufPtr = (unsigned char *) MBuffer->getBufferStart();
llvm::BitstreamReader Stream(BufPtr,BufPtr+MBuffer->getBufferSize());
if (Stream.Read(8) != 'B' ||
Stream.Read(8) != 'C' ||
Stream.Read(4) != 0xC ||
Stream.Read(4) != 0xF ||
Stream.Read(4) != 0xE ||
Stream.Read(4) != 0x0) {
// FIXME: Provide diagnostic.
return NULL;
}
// Create the deserializer.
llvm::Deserializer Dezr(Stream);
return TranslationUnit::Create(Dezr,FMgr);
}
TranslationUnit* TranslationUnit::Create(llvm::Deserializer& Dezr,
FileManager& FMgr) {
// Create the translation unit object.
TranslationUnit* TU = new TranslationUnit();
// ===---------------------------------------------------===/
// Deserialize the "Translation Unit" metadata.
// ===---------------------------------------------------===/
// Skip to the BasicMetaDataBlock. First jump to ASTContextBlock
// (which will appear earlier) and record its location.
bool FoundBlock = Dezr.SkipToBlock(ASTContextBlock);
assert (FoundBlock);
llvm::Deserializer::Location ASTContextBlockLoc =
Dezr.getCurrentBlockLocation();
FoundBlock = Dezr.SkipToBlock(BasicMetadataBlock);
assert (FoundBlock);
// Read the SourceManager.
SourceManager::CreateAndRegister(Dezr,FMgr);
// Read the LangOptions.
TU->LangOpts.Read(Dezr);
{ // Read the TargetInfo.
llvm::SerializedPtrID PtrID = Dezr.ReadPtrID();
char* triple = Dezr.ReadCStr(NULL,0,true);
Dezr.RegisterPtr(PtrID, TargetInfo::CreateTargetInfo(std::string(triple)));
delete [] triple;
}
// For Selectors, we must read the identifier table first because the
// SelectorTable depends on the identifiers being already deserialized.
llvm::Deserializer::Location SelectorBlkLoc = Dezr.getCurrentBlockLocation();
Dezr.SkipBlock();
// Read the identifier table.
IdentifierTable::CreateAndRegister(Dezr);
// Now jump back and read the selectors.
Dezr.JumpTo(SelectorBlkLoc);
SelectorTable::CreateAndRegister(Dezr);
// Now jump back to ASTContextBlock and read the ASTContext.
Dezr.JumpTo(ASTContextBlockLoc);
TU->Context = Dezr.ReadOwnedPtr<ASTContext>();
// "Rewind" the stream. Find the block with the serialized top-level decls.
Dezr.Rewind();
FoundBlock = Dezr.SkipToBlock(DeclsBlock);
assert (FoundBlock);
llvm::Deserializer::Location DeclBlockLoc = Dezr.getCurrentBlockLocation();
while (!Dezr.FinishedBlock(DeclBlockLoc))
TU->AddTopLevelDecl(Dezr.ReadOwnedPtr<Decl>(*TU->Context));
return TU;
}
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