diff options
Diffstat (limited to 'contrib/llvm/tools/bugpoint/CrashDebugger.cpp')
| -rw-r--r-- | contrib/llvm/tools/bugpoint/CrashDebugger.cpp | 672 |
1 files changed, 672 insertions, 0 deletions
diff --git a/contrib/llvm/tools/bugpoint/CrashDebugger.cpp b/contrib/llvm/tools/bugpoint/CrashDebugger.cpp new file mode 100644 index 0000000..aed16f4 --- /dev/null +++ b/contrib/llvm/tools/bugpoint/CrashDebugger.cpp @@ -0,0 +1,672 @@ +//===- CrashDebugger.cpp - Debug compilation crashes ----------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines the bugpoint internals that narrow down compilation crashes +// +//===----------------------------------------------------------------------===// + +#include "BugDriver.h" +#include "ToolRunner.h" +#include "ListReducer.h" +#include "llvm/Constants.h" +#include "llvm/DerivedTypes.h" +#include "llvm/Instructions.h" +#include "llvm/Module.h" +#include "llvm/Pass.h" +#include "llvm/PassManager.h" +#include "llvm/ValueSymbolTable.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/Analysis/Verifier.h" +#include "llvm/Support/CFG.h" +#include "llvm/Transforms/Scalar.h" +#include "llvm/Transforms/Utils/Cloning.h" +#include "llvm/Support/FileUtilities.h" +#include "llvm/Support/CommandLine.h" +#include <set> +using namespace llvm; + +namespace { + cl::opt<bool> + KeepMain("keep-main", + cl::desc("Force function reduction to keep main"), + cl::init(false)); + cl::opt<bool> + NoGlobalRM ("disable-global-remove", + cl::desc("Do not remove global variables"), + cl::init(false)); +} + +namespace llvm { + class ReducePassList : public ListReducer<std::string> { + BugDriver &BD; + public: + ReducePassList(BugDriver &bd) : BD(bd) {} + + // doTest - Return true iff running the "removed" passes succeeds, and + // running the "Kept" passes fail when run on the output of the "removed" + // passes. If we return true, we update the current module of bugpoint. + // + virtual TestResult doTest(std::vector<std::string> &Removed, + std::vector<std::string> &Kept, + std::string &Error); + }; +} + +ReducePassList::TestResult +ReducePassList::doTest(std::vector<std::string> &Prefix, + std::vector<std::string> &Suffix, + std::string &Error) { + sys::Path PrefixOutput; + Module *OrigProgram = 0; + if (!Prefix.empty()) { + outs() << "Checking to see if these passes crash: " + << getPassesString(Prefix) << ": "; + std::string PfxOutput; + if (BD.runPasses(BD.getProgram(), Prefix, PfxOutput)) + return KeepPrefix; + + PrefixOutput.set(PfxOutput); + OrigProgram = BD.Program; + + BD.Program = ParseInputFile(PrefixOutput.str(), BD.getContext()); + if (BD.Program == 0) { + errs() << BD.getToolName() << ": Error reading bitcode file '" + << PrefixOutput.str() << "'!\n"; + exit(1); + } + PrefixOutput.eraseFromDisk(); + } + + outs() << "Checking to see if these passes crash: " + << getPassesString(Suffix) << ": "; + + if (BD.runPasses(BD.getProgram(), Suffix)) { + delete OrigProgram; // The suffix crashes alone... + return KeepSuffix; + } + + // Nothing failed, restore state... + if (OrigProgram) { + delete BD.Program; + BD.Program = OrigProgram; + } + return NoFailure; +} + +namespace { + /// ReduceCrashingGlobalVariables - This works by removing the global + /// variable's initializer and seeing if the program still crashes. If it + /// does, then we keep that program and try again. + /// + class ReduceCrashingGlobalVariables : public ListReducer<GlobalVariable*> { + BugDriver &BD; + bool (*TestFn)(const BugDriver &, Module *); + public: + ReduceCrashingGlobalVariables(BugDriver &bd, + bool (*testFn)(const BugDriver &, Module *)) + : BD(bd), TestFn(testFn) {} + + virtual TestResult doTest(std::vector<GlobalVariable*> &Prefix, + std::vector<GlobalVariable*> &Kept, + std::string &Error) { + if (!Kept.empty() && TestGlobalVariables(Kept)) + return KeepSuffix; + if (!Prefix.empty() && TestGlobalVariables(Prefix)) + return KeepPrefix; + return NoFailure; + } + + bool TestGlobalVariables(std::vector<GlobalVariable*> &GVs); + }; +} + +bool +ReduceCrashingGlobalVariables::TestGlobalVariables( + std::vector<GlobalVariable*> &GVs) { + // Clone the program to try hacking it apart... + ValueToValueMapTy VMap; + Module *M = CloneModule(BD.getProgram(), VMap); + + // Convert list to set for fast lookup... + std::set<GlobalVariable*> GVSet; + + for (unsigned i = 0, e = GVs.size(); i != e; ++i) { + GlobalVariable* CMGV = cast<GlobalVariable>(VMap[GVs[i]]); + assert(CMGV && "Global Variable not in module?!"); + GVSet.insert(CMGV); + } + + outs() << "Checking for crash with only these global variables: "; + PrintGlobalVariableList(GVs); + outs() << ": "; + + // Loop over and delete any global variables which we aren't supposed to be + // playing with... + for (Module::global_iterator I = M->global_begin(), E = M->global_end(); + I != E; ++I) + if (I->hasInitializer() && !GVSet.count(I)) { + I->setInitializer(0); + I->setLinkage(GlobalValue::ExternalLinkage); + } + + // Try running the hacked up program... + if (TestFn(BD, M)) { + BD.setNewProgram(M); // It crashed, keep the trimmed version... + + // Make sure to use global variable pointers that point into the now-current + // module. + GVs.assign(GVSet.begin(), GVSet.end()); + return true; + } + + delete M; + return false; +} + +namespace { + /// ReduceCrashingFunctions reducer - This works by removing functions and + /// seeing if the program still crashes. If it does, then keep the newer, + /// smaller program. + /// + class ReduceCrashingFunctions : public ListReducer<Function*> { + BugDriver &BD; + bool (*TestFn)(const BugDriver &, Module *); + public: + ReduceCrashingFunctions(BugDriver &bd, + bool (*testFn)(const BugDriver &, Module *)) + : BD(bd), TestFn(testFn) {} + + virtual TestResult doTest(std::vector<Function*> &Prefix, + std::vector<Function*> &Kept, + std::string &Error) { + if (!Kept.empty() && TestFuncs(Kept)) + return KeepSuffix; + if (!Prefix.empty() && TestFuncs(Prefix)) + return KeepPrefix; + return NoFailure; + } + + bool TestFuncs(std::vector<Function*> &Prefix); + }; +} + +bool ReduceCrashingFunctions::TestFuncs(std::vector<Function*> &Funcs) { + + //if main isn't present, claim there is no problem + if (KeepMain && find(Funcs.begin(), Funcs.end(), + BD.getProgram()->getFunction("main")) == Funcs.end()) + return false; + + // Clone the program to try hacking it apart... + ValueToValueMapTy VMap; + Module *M = CloneModule(BD.getProgram(), VMap); + + // Convert list to set for fast lookup... + std::set<Function*> Functions; + for (unsigned i = 0, e = Funcs.size(); i != e; ++i) { + Function *CMF = cast<Function>(VMap[Funcs[i]]); + assert(CMF && "Function not in module?!"); + assert(CMF->getFunctionType() == Funcs[i]->getFunctionType() && "wrong ty"); + assert(CMF->getName() == Funcs[i]->getName() && "wrong name"); + Functions.insert(CMF); + } + + outs() << "Checking for crash with only these functions: "; + PrintFunctionList(Funcs); + outs() << ": "; + + // Loop over and delete any functions which we aren't supposed to be playing + // with... + for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) + if (!I->isDeclaration() && !Functions.count(I)) + DeleteFunctionBody(I); + + // Try running the hacked up program... + if (TestFn(BD, M)) { + BD.setNewProgram(M); // It crashed, keep the trimmed version... + + // Make sure to use function pointers that point into the now-current + // module. + Funcs.assign(Functions.begin(), Functions.end()); + return true; + } + delete M; + return false; +} + + +namespace { + /// ReduceCrashingBlocks reducer - This works by setting the terminators of + /// all terminators except the specified basic blocks to a 'ret' instruction, + /// then running the simplify-cfg pass. This has the effect of chopping up + /// the CFG really fast which can reduce large functions quickly. + /// + class ReduceCrashingBlocks : public ListReducer<const BasicBlock*> { + BugDriver &BD; + bool (*TestFn)(const BugDriver &, Module *); + public: + ReduceCrashingBlocks(BugDriver &bd, + bool (*testFn)(const BugDriver &, Module *)) + : BD(bd), TestFn(testFn) {} + + virtual TestResult doTest(std::vector<const BasicBlock*> &Prefix, + std::vector<const BasicBlock*> &Kept, + std::string &Error) { + if (!Kept.empty() && TestBlocks(Kept)) + return KeepSuffix; + if (!Prefix.empty() && TestBlocks(Prefix)) + return KeepPrefix; + return NoFailure; + } + + bool TestBlocks(std::vector<const BasicBlock*> &Prefix); + }; +} + +bool ReduceCrashingBlocks::TestBlocks(std::vector<const BasicBlock*> &BBs) { + // Clone the program to try hacking it apart... + ValueToValueMapTy VMap; + Module *M = CloneModule(BD.getProgram(), VMap); + + // Convert list to set for fast lookup... + SmallPtrSet<BasicBlock*, 8> Blocks; + for (unsigned i = 0, e = BBs.size(); i != e; ++i) + Blocks.insert(cast<BasicBlock>(VMap[BBs[i]])); + + outs() << "Checking for crash with only these blocks:"; + unsigned NumPrint = Blocks.size(); + if (NumPrint > 10) NumPrint = 10; + for (unsigned i = 0, e = NumPrint; i != e; ++i) + outs() << " " << BBs[i]->getName(); + if (NumPrint < Blocks.size()) + outs() << "... <" << Blocks.size() << " total>"; + outs() << ": "; + + // Loop over and delete any hack up any blocks that are not listed... + for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) + for (Function::iterator BB = I->begin(), E = I->end(); BB != E; ++BB) + if (!Blocks.count(BB) && BB->getTerminator()->getNumSuccessors()) { + // Loop over all of the successors of this block, deleting any PHI nodes + // that might include it. + for (succ_iterator SI = succ_begin(BB), E = succ_end(BB); SI != E; ++SI) + (*SI)->removePredecessor(BB); + + TerminatorInst *BBTerm = BB->getTerminator(); + + if (!BB->getTerminator()->getType()->isVoidTy()) + BBTerm->replaceAllUsesWith(Constant::getNullValue(BBTerm->getType())); + + // Replace the old terminator instruction. + BB->getInstList().pop_back(); + new UnreachableInst(BB->getContext(), BB); + } + + // The CFG Simplifier pass may delete one of the basic blocks we are + // interested in. If it does we need to take the block out of the list. Make + // a "persistent mapping" by turning basic blocks into <function, name> pairs. + // This won't work well if blocks are unnamed, but that is just the risk we + // have to take. + std::vector<std::pair<std::string, std::string> > BlockInfo; + + for (SmallPtrSet<BasicBlock*, 8>::iterator I = Blocks.begin(), + E = Blocks.end(); I != E; ++I) + BlockInfo.push_back(std::make_pair((*I)->getParent()->getName(), + (*I)->getName())); + + // Now run the CFG simplify pass on the function... + std::vector<std::string> Passes; + Passes.push_back("simplifycfg"); + Passes.push_back("verify"); + Module *New = BD.runPassesOn(M, Passes); + delete M; + if (!New) { + errs() << "simplifycfg failed!\n"; + exit(1); + } + M = New; + + // Try running on the hacked up program... + if (TestFn(BD, M)) { + BD.setNewProgram(M); // It crashed, keep the trimmed version... + + // Make sure to use basic block pointers that point into the now-current + // module, and that they don't include any deleted blocks. + BBs.clear(); + const ValueSymbolTable &GST = M->getValueSymbolTable(); + for (unsigned i = 0, e = BlockInfo.size(); i != e; ++i) { + Function *F = cast<Function>(GST.lookup(BlockInfo[i].first)); + ValueSymbolTable &ST = F->getValueSymbolTable(); + Value* V = ST.lookup(BlockInfo[i].second); + if (V && V->getType() == Type::getLabelTy(V->getContext())) + BBs.push_back(cast<BasicBlock>(V)); + } + return true; + } + delete M; // It didn't crash, try something else. + return false; +} + +namespace { + /// ReduceCrashingInstructions reducer - This works by removing the specified + /// non-terminator instructions and replacing them with undef. + /// + class ReduceCrashingInstructions : public ListReducer<const Instruction*> { + BugDriver &BD; + bool (*TestFn)(const BugDriver &, Module *); + public: + ReduceCrashingInstructions(BugDriver &bd, + bool (*testFn)(const BugDriver &, Module *)) + : BD(bd), TestFn(testFn) {} + + virtual TestResult doTest(std::vector<const Instruction*> &Prefix, + std::vector<const Instruction*> &Kept, + std::string &Error) { + if (!Kept.empty() && TestInsts(Kept)) + return KeepSuffix; + if (!Prefix.empty() && TestInsts(Prefix)) + return KeepPrefix; + return NoFailure; + } + + bool TestInsts(std::vector<const Instruction*> &Prefix); + }; +} + +bool ReduceCrashingInstructions::TestInsts(std::vector<const Instruction*> + &Insts) { + // Clone the program to try hacking it apart... + ValueToValueMapTy VMap; + Module *M = CloneModule(BD.getProgram(), VMap); + + // Convert list to set for fast lookup... + SmallPtrSet<Instruction*, 64> Instructions; + for (unsigned i = 0, e = Insts.size(); i != e; ++i) { + assert(!isa<TerminatorInst>(Insts[i])); + Instructions.insert(cast<Instruction>(VMap[Insts[i]])); + } + + outs() << "Checking for crash with only " << Instructions.size(); + if (Instructions.size() == 1) + outs() << " instruction: "; + else + outs() << " instructions: "; + + for (Module::iterator MI = M->begin(), ME = M->end(); MI != ME; ++MI) + for (Function::iterator FI = MI->begin(), FE = MI->end(); FI != FE; ++FI) + for (BasicBlock::iterator I = FI->begin(), E = FI->end(); I != E;) { + Instruction *Inst = I++; + if (!Instructions.count(Inst) && !isa<TerminatorInst>(Inst) && + !isa<LandingPadInst>(Inst)) { + if (!Inst->getType()->isVoidTy()) + Inst->replaceAllUsesWith(UndefValue::get(Inst->getType())); + Inst->eraseFromParent(); + } + } + + // Verify that this is still valid. + PassManager Passes; + Passes.add(createVerifierPass()); + Passes.run(*M); + + // Try running on the hacked up program... + if (TestFn(BD, M)) { + BD.setNewProgram(M); // It crashed, keep the trimmed version... + + // Make sure to use instruction pointers that point into the now-current + // module, and that they don't include any deleted blocks. + Insts.clear(); + for (SmallPtrSet<Instruction*, 64>::const_iterator I = Instructions.begin(), + E = Instructions.end(); I != E; ++I) + Insts.push_back(*I); + return true; + } + delete M; // It didn't crash, try something else. + return false; +} + +/// DebugACrash - Given a predicate that determines whether a component crashes +/// on a program, try to destructively reduce the program while still keeping +/// the predicate true. +static bool DebugACrash(BugDriver &BD, + bool (*TestFn)(const BugDriver &, Module *), + std::string &Error) { + // See if we can get away with nuking some of the global variable initializers + // in the program... + if (!NoGlobalRM && + BD.getProgram()->global_begin() != BD.getProgram()->global_end()) { + // Now try to reduce the number of global variable initializers in the + // module to something small. + Module *M = CloneModule(BD.getProgram()); + bool DeletedInit = false; + + for (Module::global_iterator I = M->global_begin(), E = M->global_end(); + I != E; ++I) + if (I->hasInitializer()) { + I->setInitializer(0); + I->setLinkage(GlobalValue::ExternalLinkage); + DeletedInit = true; + } + + if (!DeletedInit) { + delete M; // No change made... + } else { + // See if the program still causes a crash... + outs() << "\nChecking to see if we can delete global inits: "; + + if (TestFn(BD, M)) { // Still crashes? + BD.setNewProgram(M); + outs() << "\n*** Able to remove all global initializers!\n"; + } else { // No longer crashes? + outs() << " - Removing all global inits hides problem!\n"; + delete M; + + std::vector<GlobalVariable*> GVs; + + for (Module::global_iterator I = BD.getProgram()->global_begin(), + E = BD.getProgram()->global_end(); I != E; ++I) + if (I->hasInitializer()) + GVs.push_back(I); + + if (GVs.size() > 1 && !BugpointIsInterrupted) { + outs() << "\n*** Attempting to reduce the number of global " + << "variables in the testcase\n"; + + unsigned OldSize = GVs.size(); + ReduceCrashingGlobalVariables(BD, TestFn).reduceList(GVs, Error); + if (!Error.empty()) + return true; + + if (GVs.size() < OldSize) + BD.EmitProgressBitcode(BD.getProgram(), "reduced-global-variables"); + } + } + } + } + + // Now try to reduce the number of functions in the module to something small. + std::vector<Function*> Functions; + for (Module::iterator I = BD.getProgram()->begin(), + E = BD.getProgram()->end(); I != E; ++I) + if (!I->isDeclaration()) + Functions.push_back(I); + + if (Functions.size() > 1 && !BugpointIsInterrupted) { + outs() << "\n*** Attempting to reduce the number of functions " + "in the testcase\n"; + + unsigned OldSize = Functions.size(); + ReduceCrashingFunctions(BD, TestFn).reduceList(Functions, Error); + + if (Functions.size() < OldSize) + BD.EmitProgressBitcode(BD.getProgram(), "reduced-function"); + } + + // Attempt to delete entire basic blocks at a time to speed up + // convergence... this actually works by setting the terminator of the blocks + // to a return instruction then running simplifycfg, which can potentially + // shrinks the code dramatically quickly + // + if (!DisableSimplifyCFG && !BugpointIsInterrupted) { + std::vector<const BasicBlock*> Blocks; + for (Module::const_iterator I = BD.getProgram()->begin(), + E = BD.getProgram()->end(); I != E; ++I) + for (Function::const_iterator FI = I->begin(), E = I->end(); FI !=E; ++FI) + Blocks.push_back(FI); + unsigned OldSize = Blocks.size(); + ReduceCrashingBlocks(BD, TestFn).reduceList(Blocks, Error); + if (Blocks.size() < OldSize) + BD.EmitProgressBitcode(BD.getProgram(), "reduced-blocks"); + } + + // Attempt to delete instructions using bisection. This should help out nasty + // cases with large basic blocks where the problem is at one end. + if (!BugpointIsInterrupted) { + std::vector<const Instruction*> Insts; + for (Module::const_iterator MI = BD.getProgram()->begin(), + ME = BD.getProgram()->end(); MI != ME; ++MI) + for (Function::const_iterator FI = MI->begin(), FE = MI->end(); FI != FE; + ++FI) + for (BasicBlock::const_iterator I = FI->begin(), E = FI->end(); + I != E; ++I) + if (!isa<TerminatorInst>(I)) + Insts.push_back(I); + + ReduceCrashingInstructions(BD, TestFn).reduceList(Insts, Error); + } + + // FIXME: This should use the list reducer to converge faster by deleting + // larger chunks of instructions at a time! + unsigned Simplification = 2; + do { + if (BugpointIsInterrupted) break; + --Simplification; + outs() << "\n*** Attempting to reduce testcase by deleting instruc" + << "tions: Simplification Level #" << Simplification << '\n'; + + // Now that we have deleted the functions that are unnecessary for the + // program, try to remove instructions that are not necessary to cause the + // crash. To do this, we loop through all of the instructions in the + // remaining functions, deleting them (replacing any values produced with + // nulls), and then running ADCE and SimplifyCFG. If the transformed input + // still triggers failure, keep deleting until we cannot trigger failure + // anymore. + // + unsigned InstructionsToSkipBeforeDeleting = 0; + TryAgain: + + // Loop over all of the (non-terminator) instructions remaining in the + // function, attempting to delete them. + unsigned CurInstructionNum = 0; + for (Module::const_iterator FI = BD.getProgram()->begin(), + E = BD.getProgram()->end(); FI != E; ++FI) + if (!FI->isDeclaration()) + for (Function::const_iterator BI = FI->begin(), E = FI->end(); BI != E; + ++BI) + for (BasicBlock::const_iterator I = BI->begin(), E = --BI->end(); + I != E; ++I, ++CurInstructionNum) { + if (InstructionsToSkipBeforeDeleting) { + --InstructionsToSkipBeforeDeleting; + } else { + if (BugpointIsInterrupted) goto ExitLoops; + + if (isa<LandingPadInst>(I)) + continue; + + outs() << "Checking instruction: " << *I; + Module *M = BD.deleteInstructionFromProgram(I, Simplification); + + // Find out if the pass still crashes on this pass... + if (TestFn(BD, M)) { + // Yup, it does, we delete the old module, and continue trying + // to reduce the testcase... + BD.setNewProgram(M); + InstructionsToSkipBeforeDeleting = CurInstructionNum; + goto TryAgain; // I wish I had a multi-level break here! + } + + // This pass didn't crash without this instruction, try the next + // one. + delete M; + } + } + + if (InstructionsToSkipBeforeDeleting) { + InstructionsToSkipBeforeDeleting = 0; + goto TryAgain; + } + + } while (Simplification); +ExitLoops: + + // Try to clean up the testcase by running funcresolve and globaldce... + if (!BugpointIsInterrupted) { + outs() << "\n*** Attempting to perform final cleanups: "; + Module *M = CloneModule(BD.getProgram()); + M = BD.performFinalCleanups(M, true); + + // Find out if the pass still crashes on the cleaned up program... + if (TestFn(BD, M)) { + BD.setNewProgram(M); // Yup, it does, keep the reduced version... + } else { + delete M; + } + } + + BD.EmitProgressBitcode(BD.getProgram(), "reduced-simplified"); + + return false; +} + +static bool TestForOptimizerCrash(const BugDriver &BD, Module *M) { + return BD.runPasses(M); +} + +/// debugOptimizerCrash - This method is called when some pass crashes on input. +/// It attempts to prune down the testcase to something reasonable, and figure +/// out exactly which pass is crashing. +/// +bool BugDriver::debugOptimizerCrash(const std::string &ID) { + outs() << "\n*** Debugging optimizer crash!\n"; + + std::string Error; + // Reduce the list of passes which causes the optimizer to crash... + if (!BugpointIsInterrupted) + ReducePassList(*this).reduceList(PassesToRun, Error); + assert(Error.empty()); + + outs() << "\n*** Found crashing pass" + << (PassesToRun.size() == 1 ? ": " : "es: ") + << getPassesString(PassesToRun) << '\n'; + + EmitProgressBitcode(Program, ID); + + bool Success = DebugACrash(*this, TestForOptimizerCrash, Error); + assert(Error.empty()); + return Success; +} + +static bool TestForCodeGenCrash(const BugDriver &BD, Module *M) { + std::string Error; + BD.compileProgram(M, &Error); + if (!Error.empty()) { + errs() << "<crash>\n"; + return true; // Tool is still crashing. + } + errs() << '\n'; + return false; +} + +/// debugCodeGeneratorCrash - This method is called when the code generator +/// crashes on an input. It attempts to reduce the input as much as possible +/// while still causing the code generator to crash. +bool BugDriver::debugCodeGeneratorCrash(std::string &Error) { + errs() << "*** Debugging code generator crash!\n"; + + return DebugACrash(*this, TestForCodeGenCrash, Error); +} |
