Move LTO support library to a component, allowing it to be tested

more reliably across platforms.  Patch by Tom Roeder!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191343 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Peter Collingbourne
2013-09-24 23:52:22 +00:00
parent 85509802eb
commit cc48854d5d
20 changed files with 136 additions and 59 deletions

4
lib/LTO/CMakeLists.txt Normal file
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add_llvm_library(LLVMLTO
LTOModule.cpp
LTOCodeGenerator.cpp
)

22
lib/LTO/LLVMBuild.txt Normal file
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;===- ./lib/LTO/LLVMBuild.txt ----------------------------------*- Conf -*--===;
;
; The LLVM Compiler Infrastructure
;
; This file is distributed under the University of Illinois Open Source
; License. See LICENSE.TXT for details.
;
;===------------------------------------------------------------------------===;
;
; This is an LLVMBuild description file for the components in this subdirectory.
;
; For more information on the LLVMBuild system, please see:
;
; http://llvm.org/docs/LLVMBuild.html
;
;===------------------------------------------------------------------------===;
[component_0]
type = Library
name = LTO
parent = Libraries
required_libraries = Analysis BitReader BitWriter Core IPO Linker MC MCParser Scalar Support Target Vectorize

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//===-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 "llvm/LTO/LTOCodeGenerator.h"
#include "llvm/LTO/LTOModule.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/Config/config.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/InitializePasses.h"
#include "llvm/Linker.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/PassManager.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Support/system_error.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/Mangler.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/IPO/PassManagerBuilder.h"
#include "llvm/Transforms/ObjCARC.h"
using namespace llvm;
static cl::opt<bool>
DisableOpt("disable-opt", cl::init(false),
cl::desc("Do not run any optimization passes"));
static cl::opt<bool>
DisableInline("disable-inlining", cl::init(false),
cl::desc("Do not run the inliner pass"));
static cl::opt<bool>
DisableGVNLoadPRE("disable-gvn-loadpre", cl::init(false),
cl::desc("Do not run the GVN load PRE 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(new Module("ld-temp.o", Context)),
TargetMach(NULL), EmitDwarfDebugInfo(false), ScopeRestrictionsDone(false),
CodeModel(LTO_CODEGEN_PIC_MODEL_DYNAMIC), NativeObjectFile(NULL) {
initializeLTOPasses();
}
LTOCodeGenerator::~LTOCodeGenerator() {
delete TargetMach;
delete NativeObjectFile;
delete Linker.getModule();
for (std::vector<char *>::iterator I = CodegenOptions.begin(),
E = CodegenOptions.end();
I != E; ++I)
free(*I);
}
// Initialize LTO passes. Please keep this funciton in sync with
// PassManagerBuilder::populateLTOPassManager(), and make sure all LTO
// passes are initialized.
//
void LTOCodeGenerator::initializeLTOPasses() {
PassRegistry &R = *PassRegistry::getPassRegistry();
initializeInternalizePassPass(R);
initializeIPSCCPPass(R);
initializeGlobalOptPass(R);
initializeConstantMergePass(R);
initializeDAHPass(R);
initializeInstCombinerPass(R);
initializeSimpleInlinerPass(R);
initializePruneEHPass(R);
initializeGlobalDCEPass(R);
initializeArgPromotionPass(R);
initializeJumpThreadingPass(R);
initializeSROAPass(R);
initializeSROA_DTPass(R);
initializeSROA_SSAUpPass(R);
initializeFunctionAttrsPass(R);
initializeGlobalsModRefPass(R);
initializeLICMPass(R);
initializeGVNPass(R);
initializeMemCpyOptPass(R);
initializeDCEPass(R);
initializeCFGSimplifyPassPass(R);
}
bool LTOCodeGenerator::addModule(LTOModule* mod, std::string& errMsg) {
bool ret = Linker.linkInModule(mod->getLLVVMModule(), &errMsg);
const std::vector<const char*> &undefs = mod->getAsmUndefinedRefs();
for (int i = 0, e = undefs.size(); i != e; ++i)
AsmUndefinedRefs[undefs[i]] = 1;
return !ret;
}
void LTOCodeGenerator::setDebugInfo(lto_debug_model debug) {
switch (debug) {
case LTO_DEBUG_MODEL_NONE:
EmitDwarfDebugInfo = false;
return;
case LTO_DEBUG_MODEL_DWARF:
EmitDwarfDebugInfo = true;
return;
}
llvm_unreachable("Unknown debug format!");
}
void LTOCodeGenerator::setCodePICModel(lto_codegen_model model) {
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;
}
llvm_unreachable("Unknown PIC model!");
}
bool LTOCodeGenerator::writeMergedModules(const char *path,
std::string &errMsg) {
if (!determineTarget(errMsg))
return false;
// mark which symbols can not be internalized
applyScopeRestrictions();
// create output file
std::string ErrInfo;
tool_output_file Out(path, ErrInfo, sys::fs::F_Binary);
if (!ErrInfo.empty()) {
errMsg = "could not open bitcode file for writing: ";
errMsg += path;
return false;
}
// write bitcode to it
WriteBitcodeToFile(Linker.getModule(), Out.os());
Out.os().close();
if (Out.os().has_error()) {
errMsg = "could not write bitcode file: ";
errMsg += path;
Out.os().clear_error();
return false;
}
Out.keep();
return true;
}
bool LTOCodeGenerator::compile_to_file(const char** name, std::string& errMsg) {
// make unique temp .o file to put generated object file
SmallString<128> Filename;
int FD;
error_code EC = sys::fs::createTemporaryFile("lto-llvm", "o", FD, Filename);
if (EC) {
errMsg = EC.message();
return false;
}
// generate object file
tool_output_file objFile(Filename.c_str(), FD);
bool genResult = generateObjectFile(objFile.os(), errMsg);
objFile.os().close();
if (objFile.os().has_error()) {
objFile.os().clear_error();
sys::fs::remove(Twine(Filename));
return false;
}
objFile.keep();
if (!genResult) {
sys::fs::remove(Twine(Filename));
return false;
}
NativeObjectPath = Filename.c_str();
*name = NativeObjectPath.c_str();
return true;
}
const void* LTOCodeGenerator::compile(size_t* length, std::string& errMsg) {
const char *name;
if (!compile_to_file(&name, errMsg))
return NULL;
// remove old buffer if compile() called twice
delete NativeObjectFile;
// read .o file into memory buffer
OwningPtr<MemoryBuffer> BuffPtr;
if (error_code ec = MemoryBuffer::getFile(name, BuffPtr, -1, false)) {
errMsg = ec.message();
sys::fs::remove(NativeObjectPath);
return NULL;
}
NativeObjectFile = BuffPtr.take();
// remove temp files
sys::fs::remove(NativeObjectPath);
// return buffer, unless error
if (NativeObjectFile == NULL)
return NULL;
*length = NativeObjectFile->getBufferSize();
return NativeObjectFile->getBufferStart();
}
bool LTOCodeGenerator::determineTarget(std::string &errMsg) {
if (TargetMach != NULL)
return true;
// if options were requested, set them
if (!CodegenOptions.empty())
cl::ParseCommandLineOptions(CodegenOptions.size(),
const_cast<char **>(&CodegenOptions[0]));
std::string TripleStr = Linker.getModule()->getTargetTriple();
if (TripleStr.empty())
TripleStr = sys::getDefaultTargetTriple();
llvm::Triple Triple(TripleStr);
// create target machine from info for merged modules
const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg);
if (march == NULL)
return false;
// The relocation model is actually a static member of TargetMachine and
// needs to be set before the TargetMachine is instantiated.
Reloc::Model RelocModel = Reloc::Default;
switch (CodeModel) {
case LTO_CODEGEN_PIC_MODEL_STATIC:
RelocModel = Reloc::Static;
break;
case LTO_CODEGEN_PIC_MODEL_DYNAMIC:
RelocModel = Reloc::PIC_;
break;
case LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC:
RelocModel = Reloc::DynamicNoPIC;
break;
}
// construct LTOModule, hand over ownership of module and target
SubtargetFeatures Features;
Features.getDefaultSubtargetFeatures(Triple);
std::string FeatureStr = Features.getString();
// Set a default CPU for Darwin triples.
if (MCpu.empty() && Triple.isOSDarwin()) {
if (Triple.getArch() == llvm::Triple::x86_64)
MCpu = "core2";
else if (Triple.getArch() == llvm::Triple::x86)
MCpu = "yonah";
}
TargetOptions Options;
LTOModule::getTargetOptions(Options);
TargetMach = march->createTargetMachine(TripleStr, MCpu, FeatureStr, Options,
RelocModel, CodeModel::Default,
CodeGenOpt::Aggressive);
return true;
}
void LTOCodeGenerator::
applyRestriction(GlobalValue &GV,
std::vector<const char*> &MustPreserveList,
SmallPtrSet<GlobalValue*, 8> &AsmUsed,
Mangler &Mangler) {
SmallString<64> Buffer;
Mangler.getNameWithPrefix(Buffer, &GV, false);
if (GV.isDeclaration())
return;
if (MustPreserveSymbols.count(Buffer))
MustPreserveList.push_back(GV.getName().data());
if (AsmUndefinedRefs.count(Buffer))
AsmUsed.insert(&GV);
}
static void findUsedValues(GlobalVariable *LLVMUsed,
SmallPtrSet<GlobalValue*, 8> &UsedValues) {
if (LLVMUsed == 0) return;
ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i)
if (GlobalValue *GV =
dyn_cast<GlobalValue>(Inits->getOperand(i)->stripPointerCasts()))
UsedValues.insert(GV);
}
void LTOCodeGenerator::applyScopeRestrictions() {
if (ScopeRestrictionsDone)
return;
Module *mergedModule = Linker.getModule();
// Start off with a verification pass.
PassManager passes;
passes.add(createVerifierPass());
// mark which symbols can not be internalized
MCContext MContext(TargetMach->getMCAsmInfo(), TargetMach->getRegisterInfo(),
NULL);
Mangler Mangler(MContext, TargetMach);
std::vector<const char*> MustPreserveList;
SmallPtrSet<GlobalValue*, 8> AsmUsed;
for (Module::iterator f = mergedModule->begin(),
e = mergedModule->end(); f != e; ++f)
applyRestriction(*f, MustPreserveList, AsmUsed, Mangler);
for (Module::global_iterator v = mergedModule->global_begin(),
e = mergedModule->global_end(); v != e; ++v)
applyRestriction(*v, MustPreserveList, AsmUsed, Mangler);
for (Module::alias_iterator a = mergedModule->alias_begin(),
e = mergedModule->alias_end(); a != e; ++a)
applyRestriction(*a, MustPreserveList, AsmUsed, Mangler);
GlobalVariable *LLVMCompilerUsed =
mergedModule->getGlobalVariable("llvm.compiler.used");
findUsedValues(LLVMCompilerUsed, AsmUsed);
if (LLVMCompilerUsed)
LLVMCompilerUsed->eraseFromParent();
if (!AsmUsed.empty()) {
llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(Context);
std::vector<Constant*> asmUsed2;
for (SmallPtrSet<GlobalValue*, 16>::const_iterator i = AsmUsed.begin(),
e = AsmUsed.end(); i !=e; ++i) {
GlobalValue *GV = *i;
Constant *c = ConstantExpr::getBitCast(GV, i8PTy);
asmUsed2.push_back(c);
}
llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, asmUsed2.size());
LLVMCompilerUsed =
new llvm::GlobalVariable(*mergedModule, ATy, false,
llvm::GlobalValue::AppendingLinkage,
llvm::ConstantArray::get(ATy, asmUsed2),
"llvm.compiler.used");
LLVMCompilerUsed->setSection("llvm.metadata");
}
passes.add(createInternalizePass(MustPreserveList));
// apply scope restrictions
passes.run(*mergedModule);
ScopeRestrictionsDone = true;
}
/// Optimize merged modules using various IPO passes
bool LTOCodeGenerator::generateObjectFile(raw_ostream &out,
std::string &errMsg) {
if (!this->determineTarget(errMsg))
return false;
Module *mergedModule = Linker.getModule();
// Mark which symbols can not be internalized
this->applyScopeRestrictions();
// Instantiate the pass manager to organize the passes.
PassManager passes;
// Start off with a verification pass.
passes.add(createVerifierPass());
// Add an appropriate DataLayout instance for this module...
passes.add(new DataLayout(*TargetMach->getDataLayout()));
TargetMach->addAnalysisPasses(passes);
// Enabling internalize here would use its AllButMain variant. It
// keeps only main if it exists and does nothing for libraries. Instead
// we create the pass ourselves with the symbol list provided by the linker.
if (!DisableOpt)
PassManagerBuilder().populateLTOPassManager(passes,
/*Internalize=*/false,
!DisableInline,
DisableGVNLoadPRE);
// Make sure everything is still good.
passes.add(createVerifierPass());
PassManager codeGenPasses;
codeGenPasses.add(new DataLayout(*TargetMach->getDataLayout()));
TargetMach->addAnalysisPasses(codeGenPasses);
formatted_raw_ostream Out(out);
// If the bitcode files contain ARC code and were compiled with optimization,
// the ObjCARCContractPass must be run, so do it unconditionally here.
codeGenPasses.add(createObjCARCContractPass());
if (TargetMach->addPassesToEmitFile(codeGenPasses, Out,
TargetMachine::CGFT_ObjectFile)) {
errMsg = "target file type not supported";
return false;
}
// Run our queue of passes all at once now, efficiently.
passes.run(*mergedModule);
// Run the code generator, and write assembly file
codeGenPasses.run(*mergedModule);
return true;
}
/// setCodeGenDebugOptions - Set codegen debugging options to aid in debugging
/// LTO problems.
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(strdup("libLLVMLTO"));
CodegenOptions.push_back(strdup(o.first.str().c_str()));
}
}

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lib/LTO/LTOModule.cpp Normal file
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//===-- LTOModule.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 "llvm/LTO/LTOModule.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCParser/MCAsmParser.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCTargetAsmParser.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/system_error.h"
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
static cl::opt<bool>
EnableFPMAD("enable-fp-mad",
cl::desc("Enable less precise MAD instructions to be generated"),
cl::init(false));
static cl::opt<bool>
DisableFPElim("disable-fp-elim",
cl::desc("Disable frame pointer elimination optimization"),
cl::init(false));
static cl::opt<bool>
EnableUnsafeFPMath("enable-unsafe-fp-math",
cl::desc("Enable optimizations that may decrease FP precision"),
cl::init(false));
static cl::opt<bool>
EnableNoInfsFPMath("enable-no-infs-fp-math",
cl::desc("Enable FP math optimizations that assume no +-Infs"),
cl::init(false));
static cl::opt<bool>
EnableNoNaNsFPMath("enable-no-nans-fp-math",
cl::desc("Enable FP math optimizations that assume no NaNs"),
cl::init(false));
static cl::opt<bool>
EnableHonorSignDependentRoundingFPMath("enable-sign-dependent-rounding-fp-math",
cl::Hidden,
cl::desc("Force codegen to assume rounding mode can change dynamically"),
cl::init(false));
static cl::opt<bool>
GenerateSoftFloatCalls("soft-float",
cl::desc("Generate software floating point library calls"),
cl::init(false));
static cl::opt<llvm::FloatABI::ABIType>
FloatABIForCalls("float-abi",
cl::desc("Choose float ABI type"),
cl::init(FloatABI::Default),
cl::values(
clEnumValN(FloatABI::Default, "default",
"Target default float ABI type"),
clEnumValN(FloatABI::Soft, "soft",
"Soft float ABI (implied by -soft-float)"),
clEnumValN(FloatABI::Hard, "hard",
"Hard float ABI (uses FP registers)"),
clEnumValEnd));
static cl::opt<llvm::FPOpFusion::FPOpFusionMode>
FuseFPOps("fp-contract",
cl::desc("Enable aggresive formation of fused FP ops"),
cl::init(FPOpFusion::Standard),
cl::values(
clEnumValN(FPOpFusion::Fast, "fast",
"Fuse FP ops whenever profitable"),
clEnumValN(FPOpFusion::Standard, "on",
"Only fuse 'blessed' FP ops."),
clEnumValN(FPOpFusion::Strict, "off",
"Only fuse FP ops when the result won't be effected."),
clEnumValEnd));
static cl::opt<bool>
DontPlaceZerosInBSS("nozero-initialized-in-bss",
cl::desc("Don't place zero-initialized symbols into bss section"),
cl::init(false));
static cl::opt<bool>
EnableGuaranteedTailCallOpt("tailcallopt",
cl::desc("Turn fastcc calls into tail calls by (potentially) changing ABI."),
cl::init(false));
static cl::opt<bool>
DisableTailCalls("disable-tail-calls",
cl::desc("Never emit tail calls"),
cl::init(false));
static cl::opt<unsigned>
OverrideStackAlignment("stack-alignment",
cl::desc("Override default stack alignment"),
cl::init(0));
static cl::opt<std::string>
TrapFuncName("trap-func", cl::Hidden,
cl::desc("Emit a call to trap function rather than a trap instruction"),
cl::init(""));
static cl::opt<bool>
EnablePIE("enable-pie",
cl::desc("Assume the creation of a position independent executable."),
cl::init(false));
static cl::opt<bool>
SegmentedStacks("segmented-stacks",
cl::desc("Use segmented stacks if possible."),
cl::init(false));
static cl::opt<bool>
UseInitArray("use-init-array",
cl::desc("Use .init_array instead of .ctors."),
cl::init(false));
LTOModule::LTOModule(llvm::Module *m, llvm::TargetMachine *t)
: _module(m), _target(t),
_context(_target->getMCAsmInfo(), _target->getRegisterInfo(), NULL),
_mangler(_context, t) {}
/// isBitcodeFile - Returns 'true' if the file (or memory contents) is LLVM
/// bitcode.
bool LTOModule::isBitcodeFile(const void *mem, size_t length) {
return sys::fs::identify_magic(StringRef((const char *)mem, length)) ==
sys::fs::file_magic::bitcode;
}
bool LTOModule::isBitcodeFile(const char *path) {
sys::fs::file_magic type;
if (sys::fs::identify_magic(path, type))
return false;
return type == sys::fs::file_magic::bitcode;
}
/// isBitcodeFileForTarget - Returns 'true' if the file (or memory contents) is
/// LLVM bitcode for the specified triple.
bool LTOModule::isBitcodeFileForTarget(const void *mem, size_t length,
const char *triplePrefix) {
MemoryBuffer *buffer = makeBuffer(mem, length);
if (!buffer)
return false;
return isTargetMatch(buffer, triplePrefix);
}
bool LTOModule::isBitcodeFileForTarget(const char *path,
const char *triplePrefix) {
OwningPtr<MemoryBuffer> buffer;
if (MemoryBuffer::getFile(path, buffer))
return false;
return isTargetMatch(buffer.take(), triplePrefix);
}
/// isTargetMatch - Returns 'true' if the memory buffer is for the specified
/// target triple.
bool LTOModule::isTargetMatch(MemoryBuffer *buffer, const char *triplePrefix) {
std::string Triple = getBitcodeTargetTriple(buffer, getGlobalContext());
delete buffer;
return strncmp(Triple.c_str(), triplePrefix, strlen(triplePrefix)) == 0;
}
/// makeLTOModule - Create an LTOModule. N.B. These methods take ownership of
/// the buffer.
LTOModule *LTOModule::makeLTOModule(const char *path, std::string &errMsg) {
OwningPtr<MemoryBuffer> buffer;
if (error_code ec = MemoryBuffer::getFile(path, buffer)) {
errMsg = ec.message();
return NULL;
}
return makeLTOModule(buffer.take(), errMsg);
}
LTOModule *LTOModule::makeLTOModule(int fd, const char *path,
size_t size, std::string &errMsg) {
return makeLTOModule(fd, path, size, 0, errMsg);
}
LTOModule *LTOModule::makeLTOModule(int fd, const char *path,
size_t map_size,
off_t offset,
std::string &errMsg) {
OwningPtr<MemoryBuffer> buffer;
if (error_code ec =
MemoryBuffer::getOpenFileSlice(fd, path, buffer, map_size, offset)) {
errMsg = ec.message();
return NULL;
}
return makeLTOModule(buffer.take(), errMsg);
}
LTOModule *LTOModule::makeLTOModule(const void *mem, size_t length,
std::string &errMsg) {
OwningPtr<MemoryBuffer> buffer(makeBuffer(mem, length));
if (!buffer)
return NULL;
return makeLTOModule(buffer.take(), errMsg);
}
void LTOModule::getTargetOptions(TargetOptions &Options) {
Options.LessPreciseFPMADOption = EnableFPMAD;
Options.NoFramePointerElim = DisableFPElim;
Options.AllowFPOpFusion = FuseFPOps;
Options.UnsafeFPMath = EnableUnsafeFPMath;
Options.NoInfsFPMath = EnableNoInfsFPMath;
Options.NoNaNsFPMath = EnableNoNaNsFPMath;
Options.HonorSignDependentRoundingFPMathOption =
EnableHonorSignDependentRoundingFPMath;
Options.UseSoftFloat = GenerateSoftFloatCalls;
if (FloatABIForCalls != FloatABI::Default)
Options.FloatABIType = FloatABIForCalls;
Options.NoZerosInBSS = DontPlaceZerosInBSS;
Options.GuaranteedTailCallOpt = EnableGuaranteedTailCallOpt;
Options.DisableTailCalls = DisableTailCalls;
Options.StackAlignmentOverride = OverrideStackAlignment;
Options.TrapFuncName = TrapFuncName;
Options.PositionIndependentExecutable = EnablePIE;
Options.EnableSegmentedStacks = SegmentedStacks;
Options.UseInitArray = UseInitArray;
}
LTOModule *LTOModule::makeLTOModule(MemoryBuffer *buffer,
std::string &errMsg) {
// parse bitcode buffer
OwningPtr<Module> m(getLazyBitcodeModule(buffer, getGlobalContext(),
&errMsg));
if (!m) {
delete buffer;
return NULL;
}
std::string TripleStr = m->getTargetTriple();
if (TripleStr.empty())
TripleStr = sys::getDefaultTargetTriple();
llvm::Triple Triple(TripleStr);
// find machine architecture for this module
const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg);
if (!march)
return NULL;
// construct LTOModule, hand over ownership of module and target
SubtargetFeatures Features;
Features.getDefaultSubtargetFeatures(Triple);
std::string FeatureStr = Features.getString();
// Set a default CPU for Darwin triples.
std::string CPU;
if (Triple.isOSDarwin()) {
if (Triple.getArch() == llvm::Triple::x86_64)
CPU = "core2";
else if (Triple.getArch() == llvm::Triple::x86)
CPU = "yonah";
}
TargetOptions Options;
getTargetOptions(Options);
TargetMachine *target = march->createTargetMachine(TripleStr, CPU, FeatureStr,
Options);
LTOModule *Ret = new LTOModule(m.take(), target);
if (Ret->parseSymbols(errMsg)) {
delete Ret;
return NULL;
}
return Ret;
}
/// makeBuffer - Create a MemoryBuffer from a memory range.
MemoryBuffer *LTOModule::makeBuffer(const void *mem, size_t length) {
const char *startPtr = (const char*)mem;
return MemoryBuffer::getMemBuffer(StringRef(startPtr, length), "", false);
}
/// objcClassNameFromExpression - Get string that the data pointer points to.
bool
LTOModule::objcClassNameFromExpression(const Constant *c, std::string &name) {
if (const ConstantExpr *ce = dyn_cast<ConstantExpr>(c)) {
Constant *op = ce->getOperand(0);
if (GlobalVariable *gvn = dyn_cast<GlobalVariable>(op)) {
Constant *cn = gvn->getInitializer();
if (ConstantDataArray *ca = dyn_cast<ConstantDataArray>(cn)) {
if (ca->isCString()) {
name = ".objc_class_name_" + ca->getAsCString().str();
return true;
}
}
}
}
return false;
}
/// addObjCClass - Parse i386/ppc ObjC class data structure.
void LTOModule::addObjCClass(const GlobalVariable *clgv) {
const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
if (!c) return;
// second slot in __OBJC,__class is pointer to superclass name
std::string superclassName;
if (objcClassNameFromExpression(c->getOperand(1), superclassName)) {
NameAndAttributes info;
StringMap<NameAndAttributes>::value_type &entry =
_undefines.GetOrCreateValue(superclassName);
if (!entry.getValue().name) {
const char *symbolName = entry.getKey().data();
info.name = symbolName;
info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
info.isFunction = false;
info.symbol = clgv;
entry.setValue(info);
}
}
// third slot in __OBJC,__class is pointer to class name
std::string className;
if (objcClassNameFromExpression(c->getOperand(2), className)) {
StringSet::value_type &entry = _defines.GetOrCreateValue(className);
entry.setValue(1);
NameAndAttributes info;
info.name = entry.getKey().data();
info.attributes = LTO_SYMBOL_PERMISSIONS_DATA |
LTO_SYMBOL_DEFINITION_REGULAR | LTO_SYMBOL_SCOPE_DEFAULT;
info.isFunction = false;
info.symbol = clgv;
_symbols.push_back(info);
}
}
/// addObjCCategory - Parse i386/ppc ObjC category data structure.
void LTOModule::addObjCCategory(const GlobalVariable *clgv) {
const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
if (!c) return;
// second slot in __OBJC,__category is pointer to target class name
std::string targetclassName;
if (!objcClassNameFromExpression(c->getOperand(1), targetclassName))
return;
NameAndAttributes info;
StringMap<NameAndAttributes>::value_type &entry =
_undefines.GetOrCreateValue(targetclassName);
if (entry.getValue().name)
return;
const char *symbolName = entry.getKey().data();
info.name = symbolName;
info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
info.isFunction = false;
info.symbol = clgv;
entry.setValue(info);
}
/// addObjCClassRef - Parse i386/ppc ObjC class list data structure.
void LTOModule::addObjCClassRef(const GlobalVariable *clgv) {
std::string targetclassName;
if (!objcClassNameFromExpression(clgv->getInitializer(), targetclassName))
return;
NameAndAttributes info;
StringMap<NameAndAttributes>::value_type &entry =
_undefines.GetOrCreateValue(targetclassName);
if (entry.getValue().name)
return;
const char *symbolName = entry.getKey().data();
info.name = symbolName;
info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
info.isFunction = false;
info.symbol = clgv;
entry.setValue(info);
}
/// addDefinedDataSymbol - Add a data symbol as defined to the list.
void LTOModule::addDefinedDataSymbol(const GlobalValue *v) {
// Add to list of defined symbols.
addDefinedSymbol(v, false);
if (!v->hasSection() /* || !isTargetDarwin */)
return;
// Special case i386/ppc ObjC data structures in magic sections:
// The issue is that the old ObjC object format did some strange
// contortions to avoid real linker symbols. For instance, the
// ObjC class data structure is allocated statically in the executable
// that defines that class. That data structures contains a pointer to
// its superclass. But instead of just initializing that part of the
// struct to the address of its superclass, and letting the static and
// dynamic linkers do the rest, the runtime works by having that field
// instead point to a C-string that is the name of the superclass.
// At runtime the objc initialization updates that pointer and sets
// it to point to the actual super class. As far as the linker
// knows it is just a pointer to a string. But then someone wanted the
// linker to issue errors at build time if the superclass was not found.
// So they figured out a way in mach-o object format to use an absolute
// symbols (.objc_class_name_Foo = 0) and a floating reference
// (.reference .objc_class_name_Bar) to cause the linker into erroring when
// a class was missing.
// The following synthesizes the implicit .objc_* symbols for the linker
// from the ObjC data structures generated by the front end.
// special case if this data blob is an ObjC class definition
if (v->getSection().compare(0, 15, "__OBJC,__class,") == 0) {
if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
addObjCClass(gv);
}
}
// special case if this data blob is an ObjC category definition
else if (v->getSection().compare(0, 18, "__OBJC,__category,") == 0) {
if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
addObjCCategory(gv);
}
}
// special case if this data blob is the list of referenced classes
else if (v->getSection().compare(0, 18, "__OBJC,__cls_refs,") == 0) {
if (const GlobalVariable *gv = dyn_cast<GlobalVariable>(v)) {
addObjCClassRef(gv);
}
}
}
/// addDefinedFunctionSymbol - Add a function symbol as defined to the list.
void LTOModule::addDefinedFunctionSymbol(const Function *f) {
// add to list of defined symbols
addDefinedSymbol(f, true);
}
/// addDefinedSymbol - Add a defined symbol to the list.
void LTOModule::addDefinedSymbol(const GlobalValue *def, bool isFunction) {
// ignore all llvm.* symbols
if (def->getName().startswith("llvm."))
return;
// string is owned by _defines
SmallString<64> Buffer;
_mangler.getNameWithPrefix(Buffer, def, false);
// set alignment part log2() can have rounding errors
uint32_t align = def->getAlignment();
uint32_t attr = align ? countTrailingZeros(def->getAlignment()) : 0;
// set permissions part
if (isFunction) {
attr |= LTO_SYMBOL_PERMISSIONS_CODE;
} else {
const GlobalVariable *gv = dyn_cast<GlobalVariable>(def);
if (gv && gv->isConstant())
attr |= LTO_SYMBOL_PERMISSIONS_RODATA;
else
attr |= LTO_SYMBOL_PERMISSIONS_DATA;
}
// set definition part
if (def->hasWeakLinkage() || def->hasLinkOnceLinkage() ||
def->hasLinkerPrivateWeakLinkage())
attr |= LTO_SYMBOL_DEFINITION_WEAK;
else if (def->hasCommonLinkage())
attr |= LTO_SYMBOL_DEFINITION_TENTATIVE;
else
attr |= LTO_SYMBOL_DEFINITION_REGULAR;
// set scope part
if (def->hasHiddenVisibility())
attr |= LTO_SYMBOL_SCOPE_HIDDEN;
else if (def->hasProtectedVisibility())
attr |= LTO_SYMBOL_SCOPE_PROTECTED;
else if (def->hasExternalLinkage() || def->hasWeakLinkage() ||
def->hasLinkOnceLinkage() || def->hasCommonLinkage() ||
def->hasLinkerPrivateWeakLinkage())
attr |= LTO_SYMBOL_SCOPE_DEFAULT;
else if (def->hasLinkOnceODRAutoHideLinkage())
attr |= LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN;
else
attr |= LTO_SYMBOL_SCOPE_INTERNAL;
StringSet::value_type &entry = _defines.GetOrCreateValue(Buffer);
entry.setValue(1);
// fill information structure
NameAndAttributes info;
StringRef Name = entry.getKey();
info.name = Name.data();
assert(info.name[Name.size()] == '\0');
info.attributes = attr;
info.isFunction = isFunction;
info.symbol = def;
// add to table of symbols
_symbols.push_back(info);
}
/// addAsmGlobalSymbol - Add a global symbol from module-level ASM to the
/// defined list.
void LTOModule::addAsmGlobalSymbol(const char *name,
lto_symbol_attributes scope) {
StringSet::value_type &entry = _defines.GetOrCreateValue(name);
// only add new define if not already defined
if (entry.getValue())
return;
entry.setValue(1);
NameAndAttributes &info = _undefines[entry.getKey().data()];
if (info.symbol == 0) {
// FIXME: This is trying to take care of module ASM like this:
//
// module asm ".zerofill __FOO, __foo, _bar_baz_qux, 0"
//
// but is gross and its mother dresses it funny. Have the ASM parser give us
// more details for this type of situation so that we're not guessing so
// much.
// fill information structure
info.name = entry.getKey().data();
info.attributes =
LTO_SYMBOL_PERMISSIONS_DATA | LTO_SYMBOL_DEFINITION_REGULAR | scope;
info.isFunction = false;
info.symbol = 0;
// add to table of symbols
_symbols.push_back(info);
return;
}
if (info.isFunction)
addDefinedFunctionSymbol(cast<Function>(info.symbol));
else
addDefinedDataSymbol(info.symbol);
_symbols.back().attributes &= ~LTO_SYMBOL_SCOPE_MASK;
_symbols.back().attributes |= scope;
}
/// addAsmGlobalSymbolUndef - Add a global symbol from module-level ASM to the
/// undefined list.
void LTOModule::addAsmGlobalSymbolUndef(const char *name) {
StringMap<NameAndAttributes>::value_type &entry =
_undefines.GetOrCreateValue(name);
_asm_undefines.push_back(entry.getKey().data());
// we already have the symbol
if (entry.getValue().name)
return;
uint32_t attr = LTO_SYMBOL_DEFINITION_UNDEFINED;;
attr |= LTO_SYMBOL_SCOPE_DEFAULT;
NameAndAttributes info;
info.name = entry.getKey().data();
info.attributes = attr;
info.isFunction = false;
info.symbol = 0;
entry.setValue(info);
}
/// addPotentialUndefinedSymbol - Add a symbol which isn't defined just yet to a
/// list to be resolved later.
void
LTOModule::addPotentialUndefinedSymbol(const GlobalValue *decl, bool isFunc) {
// ignore all llvm.* symbols
if (decl->getName().startswith("llvm."))
return;
// ignore all aliases
if (isa<GlobalAlias>(decl))
return;
SmallString<64> name;
_mangler.getNameWithPrefix(name, decl, false);
StringMap<NameAndAttributes>::value_type &entry =
_undefines.GetOrCreateValue(name);
// we already have the symbol
if (entry.getValue().name)
return;
NameAndAttributes info;
info.name = entry.getKey().data();
if (decl->hasExternalWeakLinkage())
info.attributes = LTO_SYMBOL_DEFINITION_WEAKUNDEF;
else
info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
info.isFunction = isFunc;
info.symbol = decl;
entry.setValue(info);
}
namespace {
class RecordStreamer : public MCStreamer {
public:
enum State { NeverSeen, Global, Defined, DefinedGlobal, Used };
private:
StringMap<State> Symbols;
void markDefined(const MCSymbol &Symbol) {
State &S = Symbols[Symbol.getName()];
switch (S) {
case DefinedGlobal:
case Global:
S = DefinedGlobal;
break;
case NeverSeen:
case Defined:
case Used:
S = Defined;
break;
}
}
void markGlobal(const MCSymbol &Symbol) {
State &S = Symbols[Symbol.getName()];
switch (S) {
case DefinedGlobal:
case Defined:
S = DefinedGlobal;
break;
case NeverSeen:
case Global:
case Used:
S = Global;
break;
}
}
void markUsed(const MCSymbol &Symbol) {
State &S = Symbols[Symbol.getName()];
switch (S) {
case DefinedGlobal:
case Defined:
case Global:
break;
case NeverSeen:
case Used:
S = Used;
break;
}
}
// FIXME: mostly copied for the obj streamer.
void AddValueSymbols(const MCExpr *Value) {
switch (Value->getKind()) {
case MCExpr::Target:
// FIXME: What should we do in here?
break;
case MCExpr::Constant:
break;
case MCExpr::Binary: {
const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
AddValueSymbols(BE->getLHS());
AddValueSymbols(BE->getRHS());
break;
}
case MCExpr::SymbolRef:
markUsed(cast<MCSymbolRefExpr>(Value)->getSymbol());
break;
case MCExpr::Unary:
AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr());
break;
}
}
public:
typedef StringMap<State>::const_iterator const_iterator;
const_iterator begin() {
return Symbols.begin();
}
const_iterator end() {
return Symbols.end();
}
RecordStreamer(MCContext &Context)
: MCStreamer(SK_RecordStreamer, Context) {}
virtual void EmitInstruction(const MCInst &Inst) {
// Scan for values.
for (unsigned i = Inst.getNumOperands(); i--; )
if (Inst.getOperand(i).isExpr())
AddValueSymbols(Inst.getOperand(i).getExpr());
}
virtual void EmitLabel(MCSymbol *Symbol) {
Symbol->setSection(*getCurrentSection().first);
markDefined(*Symbol);
}
virtual void EmitDebugLabel(MCSymbol *Symbol) {
EmitLabel(Symbol);
}
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
// FIXME: should we handle aliases?
markDefined(*Symbol);
}
virtual bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) {
if (Attribute == MCSA_Global)
markGlobal(*Symbol);
return true;
}
virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size , unsigned ByteAlignment) {
markDefined(*Symbol);
}
virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) {
markDefined(*Symbol);
}
virtual void EmitBundleAlignMode(unsigned AlignPow2) {}
virtual void EmitBundleLock(bool AlignToEnd) {}
virtual void EmitBundleUnlock() {}
// Noop calls.
virtual void ChangeSection(const MCSection *Section,
const MCExpr *Subsection) {}
virtual void InitToTextSection() {}
virtual void InitSections() {}
virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {}
virtual void EmitThumbFunc(MCSymbol *Func) {}
virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {}
virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
virtual void EmitCOFFSymbolStorageClass(int StorageClass) {}
virtual void EmitCOFFSymbolType(int Type) {}
virtual void EndCOFFSymbolDef() {}
virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) {}
virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment) {}
virtual void EmitBytes(StringRef Data) {}
virtual void EmitValueImpl(const MCExpr *Value, unsigned Size) {}
virtual void EmitULEB128Value(const MCExpr *Value) {}
virtual void EmitSLEB128Value(const MCExpr *Value) {}
virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
unsigned ValueSize,
unsigned MaxBytesToEmit) {}
virtual void EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit) {}
virtual bool EmitValueToOffset(const MCExpr *Offset,
unsigned char Value ) { return false; }
virtual void EmitFileDirective(StringRef Filename) {}
virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
const MCSymbol *LastLabel,
const MCSymbol *Label,
unsigned PointerSize) {}
virtual void FinishImpl() {}
virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
RecordProcEnd(Frame);
}
static bool classof(const MCStreamer *S) {
return S->getKind() == SK_RecordStreamer;
}
};
} // end anonymous namespace
/// addAsmGlobalSymbols - Add global symbols from module-level ASM to the
/// defined or undefined lists.
bool LTOModule::addAsmGlobalSymbols(std::string &errMsg) {
const std::string &inlineAsm = _module->getModuleInlineAsm();
if (inlineAsm.empty())
return false;
OwningPtr<RecordStreamer> Streamer(new RecordStreamer(_context));
MemoryBuffer *Buffer = MemoryBuffer::getMemBuffer(inlineAsm);
SourceMgr SrcMgr;
SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());
OwningPtr<MCAsmParser> Parser(createMCAsmParser(SrcMgr,
_context, *Streamer,
*_target->getMCAsmInfo()));
const Target &T = _target->getTarget();
OwningPtr<MCInstrInfo> MCII(T.createMCInstrInfo());
OwningPtr<MCSubtargetInfo>
STI(T.createMCSubtargetInfo(_target->getTargetTriple(),
_target->getTargetCPU(),
_target->getTargetFeatureString()));
OwningPtr<MCTargetAsmParser> TAP(T.createMCAsmParser(*STI, *Parser.get(), *MCII));
if (!TAP) {
errMsg = "target " + std::string(T.getName()) +
" does not define AsmParser.";
return true;
}
Parser->setTargetParser(*TAP);
if (Parser->Run(false))
return true;
for (RecordStreamer::const_iterator i = Streamer->begin(),
e = Streamer->end(); i != e; ++i) {
StringRef Key = i->first();
RecordStreamer::State Value = i->second;
if (Value == RecordStreamer::DefinedGlobal)
addAsmGlobalSymbol(Key.data(), LTO_SYMBOL_SCOPE_DEFAULT);
else if (Value == RecordStreamer::Defined)
addAsmGlobalSymbol(Key.data(), LTO_SYMBOL_SCOPE_INTERNAL);
else if (Value == RecordStreamer::Global ||
Value == RecordStreamer::Used)
addAsmGlobalSymbolUndef(Key.data());
}
return false;
}
/// isDeclaration - Return 'true' if the global value is a declaration.
static bool isDeclaration(const GlobalValue &V) {
if (V.hasAvailableExternallyLinkage())
return true;
if (V.isMaterializable())
return false;
return V.isDeclaration();
}
/// parseSymbols - Parse the symbols from the module and model-level ASM and add
/// them to either the defined or undefined lists.
bool LTOModule::parseSymbols(std::string &errMsg) {
// add functions
for (Module::iterator f = _module->begin(), e = _module->end(); f != e; ++f) {
if (isDeclaration(*f))
addPotentialUndefinedSymbol(f, true);
else
addDefinedFunctionSymbol(f);
}
// add data
for (Module::global_iterator v = _module->global_begin(),
e = _module->global_end(); v != e; ++v) {
if (isDeclaration(*v))
addPotentialUndefinedSymbol(v, false);
else
addDefinedDataSymbol(v);
}
// add asm globals
if (addAsmGlobalSymbols(errMsg))
return true;
// add aliases
for (Module::alias_iterator a = _module->alias_begin(),
e = _module->alias_end(); a != e; ++a) {
if (isDeclaration(*a->getAliasedGlobal()))
// Is an alias to a declaration.
addPotentialUndefinedSymbol(a, false);
else
addDefinedDataSymbol(a);
}
// make symbols for all undefines
for (StringMap<NameAndAttributes>::iterator u =_undefines.begin(),
e = _undefines.end(); u != e; ++u) {
// If this symbol also has a definition, then don't make an undefine because
// it is a tentative definition.
if (_defines.count(u->getKey())) continue;
NameAndAttributes info = u->getValue();
_symbols.push_back(info);
}
return false;
}

15
lib/LTO/Makefile Normal file
View File

@@ -0,0 +1,15 @@
##===- lib/Linker/Makefile ---------------------------------*- Makefile -*-===##
#
# The LLVM Compiler Infrastructure
#
# This file is distributed under the University of Illinois Open Source
# License. See LICENSE.TXT for details.
#
##===----------------------------------------------------------------------===##
LEVEL = ../..
LIBRARYNAME = LLVMLTO
BUILD_ARCHIVE := 1
include $(LEVEL)/Makefile.common