llvm-6502/tools/lto/LTOCodeGenerator.cpp
Jeffrey Yasskin f0356fe140 Kill ModuleProvider and ghost linkage by inverting the relationship between
Modules and ModuleProviders. Because the "ModuleProvider" simply materializes
GlobalValues now, and doesn't provide modules, it's renamed to
"GVMaterializer". Code that used to need a ModuleProvider to materialize
Functions can now materialize the Functions directly. Functions no longer use a
magic linkage to record that they're materializable; they simply ask the
GVMaterializer.

Because the C ABI must never change, we can't remove LLVMModuleProviderRef or
the functions that refer to it. Instead, because Module now exposes the same
functionality ModuleProvider used to, we store a Module* in any
LLVMModuleProviderRef and translate in the wrapper methods.  The bindings to
other languages still use the ModuleProvider concept.  It would probably be
worth some time to update them to follow the C++ more closely, but I don't
intend to do it.

Fixes http://llvm.org/PR5737 and http://llvm.org/PR5735.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94686 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-27 20:34:15 +00:00

450 lines
14 KiB
C++

//===-LTOCodeGenerator.cpp - LLVM Link Time Optimizer ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Link Time Optimization library. This library is
// intended to be used by linker to optimize code at link time.
//
//===----------------------------------------------------------------------===//
#include "LTOModule.h"
#include "LTOCodeGenerator.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Linker.h"
#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/CodeGen/FileWriters.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/StandardPasses.h"
#include "llvm/Support/SystemUtils.h"
#include "llvm/System/Host.h"
#include "llvm/System/Program.h"
#include "llvm/System/Signals.h"
#include "llvm/Target/Mangler.h"
#include "llvm/Target/SubtargetFeature.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegistry.h"
#include "llvm/Target/TargetSelect.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Config/config.h"
#include <cstdlib>
#include <unistd.h>
#include <fcntl.h>
using namespace llvm;
static cl::opt<bool> DisableInline("disable-inlining",
cl::desc("Do not run the inliner pass"));
const char* LTOCodeGenerator::getVersionString()
{
#ifdef LLVM_VERSION_INFO
return PACKAGE_NAME " version " PACKAGE_VERSION ", " LLVM_VERSION_INFO;
#else
return PACKAGE_NAME " version " PACKAGE_VERSION;
#endif
}
LTOCodeGenerator::LTOCodeGenerator()
: _context(getGlobalContext()),
_linker("LinkTimeOptimizer", "ld-temp.o", _context), _target(NULL),
_emitDwarfDebugInfo(false), _scopeRestrictionsDone(false),
_codeModel(LTO_CODEGEN_PIC_MODEL_DYNAMIC),
_nativeObjectFile(NULL), _assemblerPath(NULL)
{
InitializeAllTargets();
InitializeAllAsmPrinters();
}
LTOCodeGenerator::~LTOCodeGenerator()
{
delete _target;
delete _nativeObjectFile;
}
bool LTOCodeGenerator::addModule(LTOModule* mod, std::string& errMsg)
{
return _linker.LinkInModule(mod->getLLVVMModule(), &errMsg);
}
bool LTOCodeGenerator::setDebugInfo(lto_debug_model debug, std::string& errMsg)
{
switch (debug) {
case LTO_DEBUG_MODEL_NONE:
_emitDwarfDebugInfo = false;
return false;
case LTO_DEBUG_MODEL_DWARF:
_emitDwarfDebugInfo = true;
return false;
}
errMsg = "unknown debug format";
return true;
}
bool LTOCodeGenerator::setCodePICModel(lto_codegen_model model,
std::string& errMsg)
{
switch (model) {
case LTO_CODEGEN_PIC_MODEL_STATIC:
case LTO_CODEGEN_PIC_MODEL_DYNAMIC:
case LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC:
_codeModel = model;
return false;
}
errMsg = "unknown pic model";
return true;
}
void LTOCodeGenerator::setAssemblerPath(const char* path)
{
if ( _assemblerPath )
delete _assemblerPath;
_assemblerPath = new sys::Path(path);
}
void LTOCodeGenerator::addMustPreserveSymbol(const char* sym)
{
_mustPreserveSymbols[sym] = 1;
}
bool LTOCodeGenerator::writeMergedModules(const char *path,
std::string &errMsg) {
if (determineTarget(errMsg))
return true;
// mark which symbols can not be internalized
applyScopeRestrictions();
// create output file
std::string ErrInfo;
raw_fd_ostream Out(path, ErrInfo,
raw_fd_ostream::F_Binary);
if (!ErrInfo.empty()) {
errMsg = "could not open bitcode file for writing: ";
errMsg += path;
return true;
}
// write bitcode to it
WriteBitcodeToFile(_linker.getModule(), Out);
if (Out.has_error()) {
errMsg = "could not write bitcode file: ";
errMsg += path;
return true;
}
return false;
}
const void* LTOCodeGenerator::compile(size_t* length, std::string& errMsg)
{
// make unique temp .s file to put generated assembly code
sys::Path uniqueAsmPath("lto-llvm.s");
if ( uniqueAsmPath.createTemporaryFileOnDisk(true, &errMsg) )
return NULL;
sys::RemoveFileOnSignal(uniqueAsmPath);
// generate assembly code
bool genResult = false;
{
raw_fd_ostream asmFD(uniqueAsmPath.c_str(), errMsg);
formatted_raw_ostream asmFile(asmFD);
if (!errMsg.empty())
return NULL;
genResult = this->generateAssemblyCode(asmFile, errMsg);
}
if ( genResult ) {
if ( uniqueAsmPath.exists() )
uniqueAsmPath.eraseFromDisk();
return NULL;
}
// make unique temp .o file to put generated object file
sys::PathWithStatus uniqueObjPath("lto-llvm.o");
if ( uniqueObjPath.createTemporaryFileOnDisk(true, &errMsg) ) {
if ( uniqueAsmPath.exists() )
uniqueAsmPath.eraseFromDisk();
return NULL;
}
sys::RemoveFileOnSignal(uniqueObjPath);
// assemble the assembly code
const std::string& uniqueObjStr = uniqueObjPath.str();
bool asmResult = this->assemble(uniqueAsmPath.str(), uniqueObjStr, errMsg);
if ( !asmResult ) {
// remove old buffer if compile() called twice
delete _nativeObjectFile;
// read .o file into memory buffer
_nativeObjectFile = MemoryBuffer::getFile(uniqueObjStr.c_str(),&errMsg);
}
// remove temp files
uniqueAsmPath.eraseFromDisk();
uniqueObjPath.eraseFromDisk();
// return buffer, unless error
if ( _nativeObjectFile == NULL )
return NULL;
*length = _nativeObjectFile->getBufferSize();
return _nativeObjectFile->getBufferStart();
}
bool LTOCodeGenerator::assemble(const std::string& asmPath,
const std::string& objPath, std::string& errMsg)
{
sys::Path tool;
bool needsCompilerOptions = true;
if ( _assemblerPath ) {
tool = *_assemblerPath;
needsCompilerOptions = false;
} else {
// find compiler driver
tool = sys::Program::FindProgramByName("gcc");
if ( tool.isEmpty() ) {
errMsg = "can't locate gcc";
return true;
}
}
// build argument list
std::vector<const char*> args;
llvm::Triple targetTriple(_linker.getModule()->getTargetTriple());
const char *arch = targetTriple.getArchNameForAssembler();
args.push_back(tool.c_str());
if (targetTriple.getOS() == Triple::Darwin) {
// darwin specific command line options
if (arch != NULL) {
args.push_back("-arch");
args.push_back(arch);
}
// add -static to assembler command line when code model requires
if ( (_assemblerPath != NULL) && (_codeModel == LTO_CODEGEN_PIC_MODEL_STATIC) )
args.push_back("-static");
}
if ( needsCompilerOptions ) {
args.push_back("-c");
args.push_back("-x");
args.push_back("assembler");
}
args.push_back("-o");
args.push_back(objPath.c_str());
args.push_back(asmPath.c_str());
args.push_back(0);
// invoke assembler
if ( sys::Program::ExecuteAndWait(tool, &args[0], 0, 0, 0, 0, &errMsg) ) {
errMsg = "error in assembly";
return true;
}
return false; // success
}
bool LTOCodeGenerator::determineTarget(std::string& errMsg)
{
if ( _target == NULL ) {
std::string Triple = _linker.getModule()->getTargetTriple();
if (Triple.empty())
Triple = sys::getHostTriple();
// create target machine from info for merged modules
const Target *march = TargetRegistry::lookupTarget(Triple, errMsg);
if ( march == NULL )
return true;
// The relocation model is actually a static member of TargetMachine
// and needs to be set before the TargetMachine is instantiated.
switch( _codeModel ) {
case LTO_CODEGEN_PIC_MODEL_STATIC:
TargetMachine::setRelocationModel(Reloc::Static);
break;
case LTO_CODEGEN_PIC_MODEL_DYNAMIC:
TargetMachine::setRelocationModel(Reloc::PIC_);
break;
case LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC:
TargetMachine::setRelocationModel(Reloc::DynamicNoPIC);
break;
}
// construct LTModule, hand over ownership of module and target
const std::string FeatureStr =
SubtargetFeatures::getDefaultSubtargetFeatures(llvm::Triple(Triple));
_target = march->createTargetMachine(Triple, FeatureStr);
}
return false;
}
void LTOCodeGenerator::applyScopeRestrictions()
{
if ( !_scopeRestrictionsDone ) {
Module* mergedModule = _linker.getModule();
// Start off with a verification pass.
PassManager passes;
passes.add(createVerifierPass());
// mark which symbols can not be internalized
if ( !_mustPreserveSymbols.empty() ) {
Mangler mangler(*_target->getMCAsmInfo());
std::vector<const char*> mustPreserveList;
for (Module::iterator f = mergedModule->begin(),
e = mergedModule->end(); f != e; ++f) {
if ( !f->isDeclaration()
&& _mustPreserveSymbols.count(mangler.getNameWithPrefix(f)) )
mustPreserveList.push_back(::strdup(f->getNameStr().c_str()));
}
for (Module::global_iterator v = mergedModule->global_begin(),
e = mergedModule->global_end(); v != e; ++v) {
if ( !v->isDeclaration()
&& _mustPreserveSymbols.count(mangler.getNameWithPrefix(v)) )
mustPreserveList.push_back(::strdup(v->getNameStr().c_str()));
}
passes.add(createInternalizePass(mustPreserveList));
}
// apply scope restrictions
passes.run(*mergedModule);
_scopeRestrictionsDone = true;
}
}
/// Optimize merged modules using various IPO passes
bool LTOCodeGenerator::generateAssemblyCode(formatted_raw_ostream& out,
std::string& errMsg)
{
if ( this->determineTarget(errMsg) )
return true;
// mark which symbols can not be internalized
this->applyScopeRestrictions();
Module* mergedModule = _linker.getModule();
// If target supports exception handling then enable it now.
switch (_target->getMCAsmInfo()->getExceptionHandlingType()) {
case ExceptionHandling::Dwarf:
llvm::DwarfExceptionHandling = true;
break;
case ExceptionHandling::SjLj:
llvm::SjLjExceptionHandling = true;
break;
case ExceptionHandling::None:
break;
default:
assert (0 && "Unknown exception handling model!");
}
// if options were requested, set them
if ( !_codegenOptions.empty() )
cl::ParseCommandLineOptions(_codegenOptions.size(),
(char**)&_codegenOptions[0]);
// Instantiate the pass manager to organize the passes.
PassManager passes;
// Start off with a verification pass.
passes.add(createVerifierPass());
// Add an appropriate TargetData instance for this module...
passes.add(new TargetData(*_target->getTargetData()));
createStandardLTOPasses(&passes, /*Internalize=*/ false, !DisableInline,
/*VerifyEach=*/ false);
// Make sure everything is still good.
passes.add(createVerifierPass());
FunctionPassManager* codeGenPasses = new FunctionPassManager(mergedModule);
codeGenPasses->add(new TargetData(*_target->getTargetData()));
ObjectCodeEmitter* oce = NULL;
switch (_target->addPassesToEmitFile(*codeGenPasses, out,
TargetMachine::AssemblyFile,
CodeGenOpt::Aggressive)) {
case FileModel::ElfFile:
oce = AddELFWriter(*codeGenPasses, out, *_target);
break;
case FileModel::AsmFile:
break;
case FileModel::MachOFile:
case FileModel::Error:
case FileModel::None:
errMsg = "target file type not supported";
return true;
}
if (_target->addPassesToEmitFileFinish(*codeGenPasses, oce,
CodeGenOpt::Aggressive)) {
errMsg = "target does not support generation of this file type";
return true;
}
// Run our queue of passes all at once now, efficiently.
passes.run(*mergedModule);
// Run the code generator, and write assembly file
codeGenPasses->doInitialization();
for (Module::iterator
it = mergedModule->begin(), e = mergedModule->end(); it != e; ++it)
if (!it->isDeclaration())
codeGenPasses->run(*it);
codeGenPasses->doFinalization();
return false; // success
}
/// Optimize merged modules using various IPO passes
void LTOCodeGenerator::setCodeGenDebugOptions(const char* options)
{
for (std::pair<StringRef, StringRef> o = getToken(options);
!o.first.empty(); o = getToken(o.second)) {
// ParseCommandLineOptions() expects argv[0] to be program name.
// Lazily add that.
if ( _codegenOptions.empty() )
_codegenOptions.push_back("libLTO");
_codegenOptions.push_back(strdup(o.first.str().c_str()));
}
}