llvm-6502/tools/lto-bugpoint/LTOBugPoint.cpp

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//===- LTOBugPoint.cpp - Top-Level LTO BugPoint class ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class contains all of the shared state and information that is used by
// the LTO BugPoint tool to track down bit code files that cause errors.
//
//===----------------------------------------------------------------------===//
#include "LTOBugPoint.h"
#include "llvm/PassManager.h"
#include "llvm/ModuleProvider.h"
#include "llvm/CodeGen/FileWriters.h"
#include "llvm/Target/SubtargetFeature.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetAsmInfo.h"
#include "llvm/Target/TargetMachineRegistry.h"
#include "llvm/Support/SystemUtils.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/Config/config.h"
#include <fstream>
#include <iostream>
using namespace llvm;
using namespace Reloc;
/// printBitVector - Helper function.
static void printBitVector(BitVector &BV, const char *Title) {
std::cerr << Title;
for (unsigned i = 0, e = BV.size(); i < e; i++) {
if (BV[i])
std::cerr << " " << i;
}
std::cerr << "\n";
}
/// printBitVector - Helper function.
static void printBitVectorFiles(BitVector &BV, const char *Title,
SmallVector<std::string, 16> &InFiles) {
std::cerr << Title << "\n";
for (unsigned i = 0, e = BV.size(); i < e; i++) {
if (BV[i])
std::cerr << "\t" << InFiles[i] << "\n";
}
}
/// LTOBugPoint -- Constructor. Popuate list of linker options and
/// list of linker input files.
LTOBugPoint::LTOBugPoint(std::istream &args, std::istream &ins) {
// Read linker options. Order is important here.
std::string option;
while (getline(args, option))
LinkerOptions.push_back(option);
// Read linker input files. Order is important here.
std::string inFile;
while(getline(ins, inFile))
LinkerInputFiles.push_back(inFile);
TempDir = sys::Path::GetTemporaryDirectory();
// FIXME - Use command line option to set this.
findLinkingFailure = true;
}
LTOBugPoint::~LTOBugPoint() {
TempDir.eraseFromDisk(true);
}
/// findTroubleMakers - Find minimum set of input files that causes error
/// identified by the script.
bool
LTOBugPoint::findTroubleMakers(SmallVector<std::string, 4> &TroubleMakers,
std::string &Script) {
// Reproduce original error.
if (!relinkProgram(LinkerInputFiles) && !findLinkingFailure) {
ErrMsg = " Unable to reproduce original error!";
return false;
}
if (!findLinkingFailure && !reproduceProgramError(Script)) {
ErrMsg = " Unable to reproduce original error!";
return false;
}
// Build native object files set.
unsigned Size = LinkerInputFiles.size();
BCFiles.resize(Size);
ConfirmedClean.resize(Size);
ConfirmedGuilty.resize(Size);
for (unsigned I = 0; I < Size; ++I) {
std::string &FileName = LinkerInputFiles[I];
sys::Path InputFile(FileName.c_str());
if (InputFile.isDynamicLibrary() || InputFile.isArchive()) {
ErrMsg = "Unable to handle input file " + FileName;
return false;
}
else if (InputFile.isBitcodeFile()) {
BCFiles.set(I);
if (getNativeObjectFile(FileName) == false)
return false;
}
else {
// Original native object input files are always clean.
ConfirmedClean.set(I);
NativeInputFiles.push_back(FileName);
}
}
if (BCFiles.none()) {
ErrMsg = "Unable to help!";
ErrMsg = " Need at least one input file that contains llvm bitcode";
return false;
}
// Try to reproduce error using native object files first. If the error
// occurs then this is not a LTO error.
if (!relinkProgram(NativeInputFiles)) {
ErrMsg = " Unable to link the program using all native object files!";
return false;
}
if (!findLinkingFailure && reproduceProgramError(Script) == true) {
ErrMsg = " Unable to fix program error using all native object files!";
return false;
}
printBitVector(BCFiles, "Initial set of llvm bitcode files");
identifyTroubleMakers(BCFiles);
printBitVectorFiles(ConfirmedGuilty,
"Identified minimal set of bitcode files!",
LinkerInputFiles);
return true;
}
/// getFeatureString - Return a string listing the features associated with the
/// target triple.
///
/// FIXME: This is an inelegant way of specifying the features of a
/// subtarget. It would be better if we could encode this information into the
/// IR.
std::string LTOBugPoint::getFeatureString(const char *TargetTriple) {
SubtargetFeatures Features;
if (strncmp(TargetTriple, "powerpc-apple-", 14) == 0) {
Features.AddFeature("altivec", true);
} else if (strncmp(TargetTriple, "powerpc64-apple-", 16) == 0) {
Features.AddFeature("64bit", true);
Features.AddFeature("altivec", true);
}
return Features.getString();
}
/// assembleBitcode - Generate assembly code from the module. Return false
/// in case of an error.
bool LTOBugPoint::assembleBitcode(llvm::Module *M, const char *AsmFileName) {
std::string TargetTriple = M->getTargetTriple();
std::string FeatureStr =
getFeatureString(TargetTriple.c_str());
const TargetMachineRegistry::entry* Registry =
TargetMachineRegistry::getClosestStaticTargetForModule(
*M, ErrMsg);
if ( Registry == NULL )
return false;
TargetMachine *Target = Registry->CtorFn(*M, FeatureStr.c_str());
// If target supports exception handling then enable it now.
if (Target->getTargetAsmInfo()->doesSupportExceptionHandling())
ExceptionHandling = true;
// FIXME
Target->setRelocationModel(Reloc::PIC_);
FunctionPassManager* CGPasses =
new FunctionPassManager(new ExistingModuleProvider(M));
CGPasses->add(new TargetData(*Target->getTargetData()));
MachineCodeEmitter* mce = NULL;
std::string error;
raw_ostream *Out = new raw_fd_ostream(AsmFileName, error);
if (!error.empty()) {
std::cerr << error << '\n';
delete Out;
return false;
}
switch (Target->addPassesToEmitFile(*CGPasses, *Out,
TargetMachine::AssemblyFile, true)) {
case FileModel::MachOFile:
mce = AddMachOWriter(*CGPasses, *Out, *Target);
break;
case FileModel::ElfFile:
mce = AddELFWriter(*CGPasses, *Out, *Target);
break;
case FileModel::AsmFile:
break;
case FileModel::Error:
case FileModel::None:
ErrMsg = "target file type not supported";
return false;
}
if (Target->addPassesToEmitFileFinish(*CGPasses, mce, true)) {
ErrMsg = "target does not support generation of this file type";
return false;
}
CGPasses->doInitialization();
for (Module::iterator
it = M->begin(), e = M->end(); it != e; ++it)
if (!it->isDeclaration())
CGPasses->run(*it);
CGPasses->doFinalization();
delete Out;
return true;
}
/// getNativeObjectFile - Generate native object file based from llvm
/// bitcode file. Return false in case of an error.
bool LTOBugPoint::getNativeObjectFile(std::string &FileName) {
std::auto_ptr<Module> M;
MemoryBuffer *Buffer
= MemoryBuffer::getFile(FileName.c_str(), &ErrMsg);
if (!Buffer) {
ErrMsg = "Unable to read " + FileName;
return false;
}
M.reset(ParseBitcodeFile(Buffer, &ErrMsg));
std::string TargetTriple = M->getTargetTriple();
sys::Path AsmFile(TempDir);
if(AsmFile.createTemporaryFileOnDisk(false, &ErrMsg))
return false;
if (assembleBitcode(M.get(), AsmFile.c_str()) == false) {
AsmFile.eraseFromDisk();
return false;
}
sys::Path NativeFile(TempDir);
if(NativeFile.createTemporaryFileOnDisk(false, &ErrMsg)) {
AsmFile.eraseFromDisk();
return false;
}
// find compiler driver
const sys::Path gcc = sys::Program::FindProgramByName("gcc");
if ( gcc.isEmpty() ) {
ErrMsg = "can't locate gcc";
AsmFile.eraseFromDisk();
NativeFile.eraseFromDisk();
return false;
}
// build argument list
std::vector<const char*> args;
args.push_back(gcc.c_str());
if ( TargetTriple.find("darwin") != TargetTriple.size() ) {
if (strncmp(TargetTriple.c_str(), "i686-apple-", 11) == 0) {
args.push_back("-arch");
args.push_back("i386");
}
else if (strncmp(TargetTriple.c_str(), "x86_64-apple-", 13) == 0) {
args.push_back("-arch");
args.push_back("x86_64");
}
else if (strncmp(TargetTriple.c_str(), "powerpc-apple-", 14) == 0) {
args.push_back("-arch");
args.push_back("ppc");
}
else if (strncmp(TargetTriple.c_str(), "powerpc64-apple-", 16) == 0) {
args.push_back("-arch");
args.push_back("ppc64");
}
}
args.push_back("-c");
args.push_back("-x");
args.push_back("assembler");
args.push_back("-o");
args.push_back(NativeFile.c_str());
args.push_back(AsmFile.c_str());
args.push_back(0);
// invoke assembler
if (sys::Program::ExecuteAndWait(gcc, &args[0], 0, 0, 0, 0, &ErrMsg)) {
ErrMsg = "error in assembly";
AsmFile.eraseFromDisk();
NativeFile.eraseFromDisk();
return false;
}
AsmFile.eraseFromDisk();
NativeInputFiles.push_back(NativeFile.c_str());
return true;
}
/// relinkProgram - Relink program. Return false if linking fails.
bool LTOBugPoint::relinkProgram(llvm::SmallVector<std::string, 16> &InFiles) {
if (InFiles.empty())
return false;
// Atleast three options: linker path, -o and output file name.
if (LinkerOptions.size() < 3)
return false;
const sys::Path linker = sys::Program::FindProgramByName(LinkerOptions[0]);
if (linker.isEmpty()) {
ErrMsg = "can't locate linker";
return false;
}
std::vector<const char*> Args;
for (unsigned i = 0, e = LinkerOptions.size(); i < e; ++i)
Args.push_back(LinkerOptions[i].c_str());
for (unsigned i = 0, e = InFiles.size(); i < e; ++i)
Args.push_back(InFiles[i].c_str());
Args.push_back(0);
if (sys::Program::ExecuteAndWait(linker, &Args[0], 0, 0, 0, 0, &ErrMsg)) {
ErrMsg = "error while linking program";
return false;
}
return true;
}
/// reproduceProgramError - Validate program using user provided script.
/// Return true if program error is reproduced.
bool LTOBugPoint::reproduceProgramError(std::string &Script) {
const sys::Path validator = sys::Program::FindProgramByName(Script);
if (validator.isEmpty()) {
ErrMsg = "can't locate validation script";
return false;
}
std::vector<const char*> Args;
Args.push_back(Script.c_str());
Args.push_back(0);
int result =
sys::Program::ExecuteAndWait(validator, &Args[0], 0, 0, 0, 0, &ErrMsg);
// Validation scrip returns non-zero if the error is reproduced.
if (result > 0)
// Able to reproduce program error.
return true;
else if (result < 0)
// error occured while running validation script. ErrMsg contains error
// description.
return false;
return false;
}
/// identifyTroubleMakers - Identify set of bit code files that are causing
/// the error. This is a recursive function.
void LTOBugPoint::identifyTroubleMakers(llvm::BitVector &In) {
assert (In.size() == LinkerInputFiles.size()
&& "Invalid identifyTroubleMakers input!\n");
printBitVector(In, "Processing files ");
BitVector CandidateVector;
CandidateVector.resize(LinkerInputFiles.size());
// Process first half
unsigned count = 0;
for (unsigned i = 0, e = In.size(); i < e; ++i) {
if (!ConfirmedClean[i]) {
count++;
CandidateVector.set(i);
}
if (count >= In.count()/2)
break;
}
if (CandidateVector.none())
return;
printBitVector(CandidateVector, "Candidate vector ");
// Reproduce the error using native object files for candidate files.
SmallVector<std::string, 16> CandidateFiles;
for (unsigned i = 0, e = CandidateVector.size(); i < e; ++i) {
if (CandidateVector[i] || ConfirmedClean[i])
CandidateFiles.push_back(NativeInputFiles[i]);
else
CandidateFiles.push_back(LinkerInputFiles[i]);
}
bool result = relinkProgram(CandidateFiles);
if (findLinkingFailure) {
if (result == true) {
// Candidate files are suspected.
if (CandidateVector.count() == 1) {
ConfirmedGuilty.set(CandidateVector.find_first());
return;
}
else
identifyTroubleMakers(CandidateVector);
} else {
// Candidate files are not causing this error.
for (unsigned i = 0, e = CandidateVector.size(); i < e; ++i) {
if (CandidateVector[i])
ConfirmedClean.set(i);
}
}
} else {
std::cerr << "FIXME : Not yet implemented!\n";
}
// Process remaining cadidates
CandidateVector.clear();
CandidateVector.resize(LinkerInputFiles.size());
for (unsigned i = 0, e = LinkerInputFiles.size(); i < e; ++i) {
if (!ConfirmedClean[i] && !ConfirmedGuilty[i])
CandidateVector.set(i);
}
identifyTroubleMakers(CandidateVector);
}