| //===- CrashDebugger.cpp - Debug compilation crashes ----------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and 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 "ListReducer.h" |
| #include "llvm/Constant.h" |
| #include "llvm/iTerminators.h" |
| #include "llvm/Module.h" |
| #include "llvm/Pass.h" |
| #include "llvm/PassManager.h" |
| #include "llvm/SymbolTable.h" |
| #include "llvm/Type.h" |
| #include "llvm/Analysis/Verifier.h" |
| #include "llvm/Bytecode/Writer.h" |
| #include "llvm/Support/CFG.h" |
| #include "llvm/Transforms/Scalar.h" |
| #include "llvm/Transforms/Utils/Cloning.h" |
| #include "Support/FileUtilities.h" |
| #include <fstream> |
| #include <set> |
| |
| namespace llvm { |
| |
| class DebugCrashes : public ListReducer<const PassInfo*> { |
| BugDriver &BD; |
| public: |
| DebugCrashes(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<const PassInfo*> &Removed, |
| std::vector<const PassInfo*> &Kept); |
| }; |
| |
| DebugCrashes::TestResult |
| DebugCrashes::doTest(std::vector<const PassInfo*> &Prefix, |
| std::vector<const PassInfo*> &Suffix) { |
| std::string PrefixOutput; |
| Module *OrigProgram = 0; |
| if (!Prefix.empty()) { |
| std::cout << "Checking to see if these passes crash: " |
| << getPassesString(Prefix) << ": "; |
| if (BD.runPasses(Prefix, PrefixOutput)) |
| return KeepPrefix; |
| |
| OrigProgram = BD.Program; |
| |
| BD.Program = BD.ParseInputFile(PrefixOutput); |
| if (BD.Program == 0) { |
| std::cerr << BD.getToolName() << ": Error reading bytecode file '" |
| << PrefixOutput << "'!\n"; |
| exit(1); |
| } |
| removeFile(PrefixOutput); |
| } |
| |
| std::cout << "Checking to see if these passes crash: " |
| << getPassesString(Suffix) << ": "; |
| |
| if (BD.runPasses(Suffix)) { |
| delete OrigProgram; // The suffix crashes alone... |
| return KeepSuffix; |
| } |
| |
| // Nothing failed, restore state... |
| if (OrigProgram) { |
| delete BD.Program; |
| BD.Program = OrigProgram; |
| } |
| return NoFailure; |
| } |
| |
| class ReduceCrashingFunctions : public ListReducer<Function*> { |
| BugDriver &BD; |
| public: |
| ReduceCrashingFunctions(BugDriver &bd) : BD(bd) {} |
| |
| virtual TestResult doTest(std::vector<Function*> &Prefix, |
| std::vector<Function*> &Kept) { |
| 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) { |
| // Clone the program to try hacking it apart... |
| Module *M = CloneModule(BD.Program); |
| |
| // Convert list to set for fast lookup... |
| std::set<Function*> Functions; |
| for (unsigned i = 0, e = Funcs.size(); i != e; ++i) { |
| Function *CMF = M->getFunction(Funcs[i]->getName(), |
| Funcs[i]->getFunctionType()); |
| assert(CMF && "Function not in module?!"); |
| Functions.insert(CMF); |
| } |
| |
| std::cout << "Checking for crash with only these functions:"; |
| unsigned NumPrint = Funcs.size(); |
| if (NumPrint > 10) NumPrint = 10; |
| for (unsigned i = 0; i != NumPrint; ++i) |
| std::cout << " " << Funcs[i]->getName(); |
| if (NumPrint < Funcs.size()) |
| std::cout << "... <" << Funcs.size() << " total>"; |
| std::cout << ": "; |
| |
| // 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->isExternal() && !Functions.count(I)) |
| DeleteFunctionBody(I); |
| |
| // Try running the hacked up program... |
| std::swap(BD.Program, M); |
| if (BD.runPasses(BD.PassesToRun)) { |
| delete 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 BD.Program; // It didn't crash, revert... |
| BD.Program = M; |
| return false; |
| } |
| |
| |
| /// 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<BasicBlock*> { |
| BugDriver &BD; |
| public: |
| ReduceCrashingBlocks(BugDriver &bd) : BD(bd) {} |
| |
| virtual TestResult doTest(std::vector<BasicBlock*> &Prefix, |
| std::vector<BasicBlock*> &Kept) { |
| if (!Kept.empty() && TestBlocks(Kept)) |
| return KeepSuffix; |
| if (!Prefix.empty() && TestBlocks(Prefix)) |
| return KeepPrefix; |
| return NoFailure; |
| } |
| |
| bool TestBlocks(std::vector<BasicBlock*> &Prefix); |
| }; |
| |
| bool ReduceCrashingBlocks::TestBlocks(std::vector<BasicBlock*> &BBs) { |
| // Clone the program to try hacking it apart... |
| Module *M = CloneModule(BD.Program); |
| |
| // Convert list to set for fast lookup... |
| std::set<BasicBlock*> Blocks; |
| for (unsigned i = 0, e = BBs.size(); i != e; ++i) { |
| // Convert the basic block from the original module to the new module... |
| Function *F = BBs[i]->getParent(); |
| Function *CMF = M->getFunction(F->getName(), F->getFunctionType()); |
| assert(CMF && "Function not in module?!"); |
| |
| // Get the mapped basic block... |
| Function::iterator CBI = CMF->begin(); |
| std::advance(CBI, std::distance(F->begin(), Function::iterator(BBs[i]))); |
| Blocks.insert(CBI); |
| } |
| |
| std::cout << "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) |
| std::cout << " " << BBs[i]->getName(); |
| if (NumPrint < Blocks.size()) |
| std::cout << "... <" << Blocks.size() << " total>"; |
| std::cout << ": "; |
| |
| // 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) && !isa<ReturnInst>(BB->getTerminator())) { |
| // 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); |
| |
| // Delete the old terminator instruction... |
| BB->getInstList().pop_back(); |
| |
| // Add a new return instruction of the appropriate type... |
| const Type *RetTy = BB->getParent()->getReturnType(); |
| ReturnInst *RI = new ReturnInst(RetTy == Type::VoidTy ? 0 : |
| Constant::getNullValue(RetTy)); |
| BB->getInstList().push_back(RI); |
| } |
| |
| // 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<Function*, std::string> > BlockInfo; |
| |
| for (std::set<BasicBlock*>::iterator I = Blocks.begin(), E = Blocks.end(); |
| I != E; ++I) |
| BlockInfo.push_back(std::make_pair((*I)->getParent(), (*I)->getName())); |
| |
| // Now run the CFG simplify pass on the function... |
| PassManager Passes; |
| Passes.add(createCFGSimplificationPass()); |
| Passes.add(createVerifierPass()); |
| Passes.run(*M); |
| |
| // Try running on the hacked up program... |
| std::swap(BD.Program, M); |
| if (BD.runPasses(BD.PassesToRun)) { |
| delete 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(); |
| for (unsigned i = 0, e = BlockInfo.size(); i != e; ++i) { |
| SymbolTable &ST = BlockInfo[i].first->getSymbolTable(); |
| SymbolTable::iterator I = ST.find(Type::LabelTy); |
| if (I != ST.end() && I->second.count(BlockInfo[i].second)) |
| BBs.push_back(cast<BasicBlock>(I->second[BlockInfo[i].second])); |
| } |
| return true; |
| } |
| delete BD.Program; // It didn't crash, revert... |
| BD.Program = M; |
| return false; |
| } |
| |
| /// debugCrash - 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::debugCrash() { |
| bool AnyReduction = false; |
| std::cout << "\n*** Debugging optimizer crash!\n"; |
| |
| // Reduce the list of passes which causes the optimizer to crash... |
| unsigned OldSize = PassesToRun.size(); |
| DebugCrashes(*this).reduceList(PassesToRun); |
| |
| std::cout << "\n*** Found crashing pass" |
| << (PassesToRun.size() == 1 ? ": " : "es: ") |
| << getPassesString(PassesToRun) << "\n"; |
| |
| EmitProgressBytecode("passinput"); |
| |
| // See if we can get away with nuking all of the global variable initializers |
| // in the program... |
| if (Program->gbegin() != Program->gend()) { |
| Module *M = CloneModule(Program); |
| bool DeletedInit = false; |
| for (Module::giterator I = M->gbegin(), E = M->gend(); 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... |
| std::cout << "\nChecking to see if we can delete global inits: "; |
| std::swap(Program, M); |
| if (runPasses(PassesToRun)) { // Still crashes? |
| AnyReduction = true; |
| delete M; |
| std::cout << "\n*** Able to remove all global initializers!\n"; |
| } else { // No longer crashes? |
| delete Program; // Restore program. |
| Program = M; |
| std::cout << " - Removing all global inits hides problem!\n"; |
| } |
| } |
| } |
| |
| // Now try to reduce the number of functions in the module to something small. |
| std::vector<Function*> Functions; |
| for (Module::iterator I = Program->begin(), E = Program->end(); I != E; ++I) |
| if (!I->isExternal()) |
| Functions.push_back(I); |
| |
| if (Functions.size() > 1) { |
| std::cout << "\n*** Attempting to reduce the number of functions " |
| "in the testcase\n"; |
| |
| OldSize = Functions.size(); |
| ReduceCrashingFunctions(*this).reduceList(Functions); |
| |
| if (Functions.size() < OldSize) { |
| EmitProgressBytecode("reduced-function"); |
| AnyReduction = true; |
| } |
| } |
| |
| // 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) { |
| std::vector<BasicBlock*> Blocks; |
| for (Module::iterator I = Program->begin(), E = Program->end(); I != E; ++I) |
| for (Function::iterator FI = I->begin(), E = I->end(); FI != E; ++FI) |
| Blocks.push_back(FI); |
| ReduceCrashingBlocks(*this).reduceList(Blocks); |
| } |
| |
| // FIXME: This should use the list reducer to converge faster by deleting |
| // larger chunks of instructions at a time! |
| unsigned Simplification = 4; |
| do { |
| --Simplification; |
| std::cout << "\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. |
| // |
| TryAgain: |
| |
| // Loop over all of the (non-terminator) instructions remaining in the |
| // function, attempting to delete them. |
| for (Module::iterator FI = Program->begin(), E = Program->end(); |
| FI != E; ++FI) |
| if (!FI->isExternal()) { |
| for (Function::iterator BI = FI->begin(), E = FI->end(); BI != E; ++BI) |
| for (BasicBlock::iterator I = BI->begin(), E = --BI->end(); |
| I != E; ++I) { |
| Module *M = deleteInstructionFromProgram(I, Simplification); |
| |
| // Make the function the current program... |
| std::swap(Program, M); |
| |
| // Find out if the pass still crashes on this pass... |
| std::cout << "Checking instruction '" << I->getName() << "': "; |
| if (runPasses(PassesToRun)) { |
| // Yup, it does, we delete the old module, and continue trying to |
| // reduce the testcase... |
| delete M; |
| AnyReduction = true; |
| goto TryAgain; // I wish I had a multi-level break here! |
| } |
| |
| // This pass didn't crash without this instruction, try the next |
| // one. |
| delete Program; |
| Program = M; |
| } |
| } |
| } while (Simplification); |
| |
| // Try to clean up the testcase by running funcresolve and globaldce... |
| std::cout << "\n*** Attempting to perform final cleanups: "; |
| Module *M = CloneModule(Program); |
| M = performFinalCleanups(M, true); |
| std::swap(Program, M); |
| |
| // Find out if the pass still crashes on the cleaned up program... |
| if (runPasses(PassesToRun)) { |
| // Yup, it does, keep the reduced version... |
| delete M; |
| AnyReduction = true; |
| } else { |
| delete Program; // Otherwise, restore the original module... |
| Program = M; |
| } |
| |
| if (AnyReduction) |
| EmitProgressBytecode("reduced-simplified"); |
| |
| return false; |
| } |
| |
| } // End llvm namespace |