| //===- TraceValues.cpp - Value Tracing for debugging -------------*- C++ -*--=// |
| // |
| // Support for inserting LLVM code to print values at basic block and function |
| // exits. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Transforms/Instrumentation.h" |
| #include "llvm/Constants.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/iMemory.h" |
| #include "llvm/iTerminators.h" |
| #include "llvm/iOther.h" |
| #include "llvm/Module.h" |
| #include "llvm/Pass.h" |
| #include "llvm/Assembly/Writer.h" |
| #include "Support/CommandLine.h" |
| #include "Support/StringExtras.h" |
| #include <algorithm> |
| #include <sstream> |
| using std::vector; |
| using std::string; |
| |
| static cl::opt<bool> |
| DisablePtrHashing("tracedisablehashdisable", cl::Hidden, |
| cl::desc("Disable pointer hashing in the -trace or -tracem " |
| "passes")); |
| |
| static cl::list<string> |
| TraceFuncNames("tracefunc", cl::desc("Only trace specific functions in the " |
| "-trace or -tracem passes"), |
| cl::value_desc("function"), cl::Hidden); |
| |
| static void TraceValuesAtBBExit(BasicBlock *BB, |
| Function *Printf, Function* HashPtrToSeqNum, |
| vector<Instruction*> *valuesStoredInFunction); |
| |
| // We trace a particular function if no functions to trace were specified |
| // or if the function is in the specified list. |
| // |
| inline static bool |
| TraceThisFunction(Function &F) |
| { |
| if (TraceFuncNames.empty()) return true; |
| |
| return std::find(TraceFuncNames.begin(), TraceFuncNames.end(), F.getName()) |
| != TraceFuncNames.end(); |
| } |
| |
| |
| namespace { |
| struct ExternalFuncs { |
| Function *PrintfFunc, *HashPtrFunc, *ReleasePtrFunc; |
| Function *RecordPtrFunc, *PushOnEntryFunc, *ReleaseOnReturnFunc; |
| void doInitialization(Module &M); // Add prototypes for external functions |
| }; |
| |
| class InsertTraceCode : public FunctionPass { |
| protected: |
| ExternalFuncs externalFuncs; |
| public: |
| |
| // Add a prototype for runtime functions not already in the program. |
| // |
| bool doInitialization(Module &M); |
| |
| //-------------------------------------------------------------------------- |
| // Function InsertCodeToTraceValues |
| // |
| // Inserts tracing code for all live values at basic block and/or function |
| // exits as specified by `traceBasicBlockExits' and `traceFunctionExits'. |
| // |
| bool doit(Function *M); |
| |
| virtual void handleBasicBlock(BasicBlock *BB, vector<Instruction*> &VI) = 0; |
| |
| // runOnFunction - This method does the work. |
| // |
| bool runOnFunction(Function &F); |
| |
| virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
| AU.setPreservesCFG(); |
| } |
| }; |
| |
| struct FunctionTracer : public InsertTraceCode { |
| // Ignore basic blocks here... |
| virtual void handleBasicBlock(BasicBlock *BB, vector<Instruction*> &VI) {} |
| }; |
| |
| struct BasicBlockTracer : public InsertTraceCode { |
| // Trace basic blocks here... |
| virtual void handleBasicBlock(BasicBlock *BB, vector<Instruction*> &VI) { |
| TraceValuesAtBBExit(BB, externalFuncs.PrintfFunc, |
| externalFuncs.HashPtrFunc, &VI); |
| } |
| }; |
| |
| // Register the passes... |
| RegisterOpt<FunctionTracer> X("tracem","Insert Function trace code only"); |
| RegisterOpt<BasicBlockTracer> Y("trace","Insert BB and Function trace code"); |
| } // end anonymous namespace |
| |
| |
| Pass *createTraceValuesPassForFunction() { // Just trace functions |
| return new FunctionTracer(); |
| } |
| |
| Pass *createTraceValuesPassForBasicBlocks() { // Trace BB's and functions |
| return new BasicBlockTracer(); |
| } |
| |
| |
| // Add a prototype for external functions used by the tracing code. |
| // |
| void ExternalFuncs::doInitialization(Module &M) { |
| const Type *SBP = PointerType::get(Type::SByteTy); |
| const FunctionType *MTy = |
| FunctionType::get(Type::IntTy, vector<const Type*>(1, SBP), true); |
| PrintfFunc = M.getOrInsertFunction("printf", MTy); |
| |
| // uint (sbyte*) |
| const FunctionType *hashFuncTy = |
| FunctionType::get(Type::UIntTy, vector<const Type*>(1, SBP), false); |
| HashPtrFunc = M.getOrInsertFunction("HashPointerToSeqNum", hashFuncTy); |
| |
| // void (sbyte*) |
| const FunctionType *voidSBPFuncTy = |
| FunctionType::get(Type::VoidTy, vector<const Type*>(1, SBP), false); |
| |
| ReleasePtrFunc = M.getOrInsertFunction("ReleasePointerSeqNum", voidSBPFuncTy); |
| RecordPtrFunc = M.getOrInsertFunction("RecordPointer", voidSBPFuncTy); |
| |
| const FunctionType *voidvoidFuncTy = |
| FunctionType::get(Type::VoidTy, vector<const Type*>(), false); |
| |
| PushOnEntryFunc = M.getOrInsertFunction("PushPointerSet", voidvoidFuncTy); |
| ReleaseOnReturnFunc = M.getOrInsertFunction("ReleasePointersPopSet", |
| voidvoidFuncTy); |
| } |
| |
| |
| // Add a prototype for external functions used by the tracing code. |
| // |
| bool InsertTraceCode::doInitialization(Module &M) { |
| externalFuncs.doInitialization(M); |
| return false; |
| } |
| |
| |
| static inline GlobalVariable *getStringRef(Module *M, const string &str) { |
| // Create a constant internal string reference... |
| Constant *Init = ConstantArray::get(str); |
| |
| // Create the global variable and record it in the module |
| // The GV will be renamed to a unique name if needed. |
| GlobalVariable *GV = new GlobalVariable(Init->getType(), true, |
| GlobalValue::InternalLinkage, Init, |
| "trstr"); |
| M->getGlobalList().push_back(GV); |
| return GV; |
| } |
| |
| |
| // |
| // Check if this instruction has any uses outside its basic block, |
| // or if it used by either a Call or Return instruction (ditto). |
| // (Values stored to memory within this BB are live at end of BB but are |
| // traced at the store instruction, not where they are computed.) |
| // |
| static inline bool LiveAtBBExit(const Instruction* I) { |
| const BasicBlock *BB = I->getParent(); |
| for (Value::use_const_iterator U = I->use_begin(); U != I->use_end(); ++U) |
| if (const Instruction *UI = dyn_cast<Instruction>(*U)) |
| if (UI->getParent() != BB || isa<ReturnInst>(UI)) |
| return true; |
| |
| return false; |
| } |
| |
| |
| static inline bool TraceThisOpCode(unsigned opCode) { |
| // Explicitly test for opCodes *not* to trace so that any new opcodes will |
| // be traced by default (VoidTy's are already excluded) |
| // |
| return (opCode < Instruction::OtherOpsBegin && |
| opCode != Instruction::Alloca && |
| opCode != Instruction::PHINode && |
| opCode != Instruction::Cast); |
| } |
| |
| |
| // Trace a value computed by an instruction if it is non-void, it is computed |
| // by a real computation, not just a copy (see TraceThisOpCode), and |
| // -- it is a load instruction: we want to check values read from memory |
| // -- or it is live at exit from the basic block (i.e., ignore local temps) |
| // |
| static bool ShouldTraceValue(const Instruction *I) { |
| return |
| I->getType() != Type::VoidTy && |
| TraceThisOpCode(I->getOpcode()) && |
| (isa<LoadInst>(I) || LiveAtBBExit(I)); |
| } |
| |
| static string getPrintfCodeFor(const Value *V) { |
| if (V == 0) return ""; |
| if (V->getType()->isFloatingPoint()) |
| return "%g"; |
| else if (V->getType() == Type::LabelTy) |
| return "0x%p"; |
| else if (isa<PointerType>(V->getType())) |
| return DisablePtrHashing ? "0x%p" : "%d"; |
| else if (V->getType()->isIntegral()) |
| return "%d"; |
| |
| assert(0 && "Illegal value to print out..."); |
| return ""; |
| } |
| |
| |
| static void InsertPrintInst(Value *V, BasicBlock *BB, Instruction *InsertBefore, |
| string Message, |
| Function *Printf, Function* HashPtrToSeqNum) { |
| // Escape Message by replacing all % characters with %% chars. |
| string Tmp; |
| std::swap(Tmp, Message); |
| string::iterator I = std::find(Tmp.begin(), Tmp.end(), '%'); |
| while (I != Tmp.end()) { |
| Message.append(Tmp.begin(), I); |
| Message += "%%"; |
| ++I; // Make sure to erase the % as well... |
| Tmp.erase(Tmp.begin(), I); |
| I = std::find(Tmp.begin(), Tmp.end(), '%'); |
| } |
| Message += Tmp; |
| Module *Mod = BB->getParent()->getParent(); |
| |
| // Turn the marker string into a global variable... |
| GlobalVariable *fmtVal = getStringRef(Mod, Message+getPrintfCodeFor(V)+"\n"); |
| |
| // Turn the format string into an sbyte * |
| Constant *GEP =ConstantExpr::getGetElementPtr(ConstantPointerRef::get(fmtVal), |
| vector<Constant*>(2,Constant::getNullValue(Type::LongTy))); |
| |
| // Insert a call to the hash function if this is a pointer value |
| if (V && isa<PointerType>(V->getType()) && !DisablePtrHashing) { |
| const Type *SBP = PointerType::get(Type::SByteTy); |
| if (V->getType() != SBP) // Cast pointer to be sbyte* |
| V = new CastInst(V, SBP, "Hash_cast", InsertBefore); |
| |
| vector<Value*> HashArgs(1, V); |
| V = new CallInst(HashPtrToSeqNum, HashArgs, "ptrSeqNum", InsertBefore); |
| } |
| |
| // Insert the first print instruction to print the string flag: |
| vector<Value*> PrintArgs; |
| PrintArgs.push_back(GEP); |
| if (V) PrintArgs.push_back(V); |
| new CallInst(Printf, PrintArgs, "trace", InsertBefore); |
| } |
| |
| |
| static void InsertVerbosePrintInst(Value *V, BasicBlock *BB, |
| Instruction *InsertBefore, |
| const string &Message, Function *Printf, |
| Function* HashPtrToSeqNum) { |
| std::ostringstream OutStr; |
| if (V) WriteAsOperand(OutStr, V); |
| InsertPrintInst(V, BB, InsertBefore, Message+OutStr.str()+" = ", |
| Printf, HashPtrToSeqNum); |
| } |
| |
| static void |
| InsertReleaseInst(Value *V, BasicBlock *BB, |
| Instruction *InsertBefore, |
| Function* ReleasePtrFunc) { |
| |
| const Type *SBP = PointerType::get(Type::SByteTy); |
| if (V->getType() != SBP) // Cast pointer to be sbyte* |
| V = new CastInst(V, SBP, "RPSN_cast", InsertBefore); |
| |
| vector<Value*> releaseArgs(1, V); |
| new CallInst(ReleasePtrFunc, releaseArgs, "", InsertBefore); |
| } |
| |
| static void |
| InsertRecordInst(Value *V, BasicBlock *BB, |
| Instruction *InsertBefore, |
| Function* RecordPtrFunc) { |
| const Type *SBP = PointerType::get(Type::SByteTy); |
| if (V->getType() != SBP) // Cast pointer to be sbyte* |
| V = new CastInst(V, SBP, "RP_cast", InsertBefore); |
| |
| vector<Value*> releaseArgs(1, V); |
| new CallInst(RecordPtrFunc, releaseArgs, "", InsertBefore); |
| } |
| |
| // Look for alloca and free instructions. These are the ptrs to release. |
| // Release the free'd pointers immediately. Record the alloca'd pointers |
| // to be released on return from the current function. |
| // |
| static void |
| ReleasePtrSeqNumbers(BasicBlock *BB, |
| ExternalFuncs& externalFuncs) { |
| |
| for (BasicBlock::iterator II=BB->begin(), IE = BB->end(); II != IE; ++II) |
| if (FreeInst *FI = dyn_cast<FreeInst>(II)) |
| InsertReleaseInst(FI->getOperand(0), BB, FI,externalFuncs.ReleasePtrFunc); |
| else if (AllocaInst *AI = dyn_cast<AllocaInst>(II)) |
| InsertRecordInst(AI, BB, AI->getNext(), externalFuncs.RecordPtrFunc); |
| } |
| |
| |
| // Insert print instructions at the end of basic block BB for each value |
| // computed in BB that is live at the end of BB, |
| // or that is stored to memory in BB. |
| // If the value is stored to memory, we load it back before printing it |
| // We also return all such loaded values in the vector valuesStoredInFunction |
| // for printing at the exit from the function. (Note that in each invocation |
| // of the function, this will only get the last value stored for each static |
| // store instruction). |
| // |
| static void TraceValuesAtBBExit(BasicBlock *BB, |
| Function *Printf, Function* HashPtrToSeqNum, |
| vector<Instruction*> *valuesStoredInFunction) { |
| // Get an iterator to point to the insertion location, which is |
| // just before the terminator instruction. |
| // |
| TerminatorInst *InsertPos = BB->getTerminator(); |
| |
| std::ostringstream OutStr; |
| WriteAsOperand(OutStr, BB, false); |
| InsertPrintInst(0, BB, InsertPos, "LEAVING BB:" + OutStr.str(), |
| Printf, HashPtrToSeqNum); |
| |
| // Insert a print instruction for each instruction preceding InsertPos. |
| // The print instructions must go before InsertPos, so we use the |
| // instruction *preceding* InsertPos to check when to terminate the loop. |
| // |
| for (BasicBlock::iterator II = BB->begin(); &*II != InsertPos; ++II) { |
| if (StoreInst *SI = dyn_cast<StoreInst>(II)) { |
| // Trace the stored value and address |
| InsertVerbosePrintInst(SI->getOperand(0), BB, InsertPos, |
| " (store value) ", Printf, HashPtrToSeqNum); |
| InsertVerbosePrintInst(SI->getOperand(1), BB, InsertPos, |
| " (store addr ) ", Printf, HashPtrToSeqNum); |
| } |
| else if (ShouldTraceValue(II)) |
| InsertVerbosePrintInst(II, BB, InsertPos, " ", Printf, HashPtrToSeqNum); |
| } |
| } |
| |
| static inline void InsertCodeToShowFunctionEntry(Function &F, Function *Printf, |
| Function* HashPtrToSeqNum){ |
| // Get an iterator to point to the insertion location |
| BasicBlock &BB = F.getEntryNode(); |
| Instruction *InsertPos = BB.begin(); |
| |
| std::ostringstream OutStr; |
| WriteAsOperand(OutStr, &F); |
| InsertPrintInst(0, &BB, InsertPos, "ENTERING FUNCTION: " + OutStr.str(), |
| Printf, HashPtrToSeqNum); |
| |
| // Now print all the incoming arguments |
| unsigned ArgNo = 0; |
| for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I, ++ArgNo){ |
| InsertVerbosePrintInst(I, &BB, InsertPos, |
| " Arg #" + utostr(ArgNo) + ": ", Printf, |
| HashPtrToSeqNum); |
| } |
| } |
| |
| |
| static inline void InsertCodeToShowFunctionExit(BasicBlock *BB, |
| Function *Printf, |
| Function* HashPtrToSeqNum) { |
| // Get an iterator to point to the insertion location |
| ReturnInst *Ret = cast<ReturnInst>(BB->getTerminator()); |
| |
| std::ostringstream OutStr; |
| WriteAsOperand(OutStr, BB->getParent(), true); |
| InsertPrintInst(0, BB, Ret, "LEAVING FUNCTION: " + OutStr.str(), |
| Printf, HashPtrToSeqNum); |
| |
| // print the return value, if any |
| if (BB->getParent()->getReturnType() != Type::VoidTy) |
| InsertPrintInst(Ret->getReturnValue(), BB, Ret, " Returning: ", |
| Printf, HashPtrToSeqNum); |
| } |
| |
| |
| bool InsertTraceCode::runOnFunction(Function &F) { |
| if (!TraceThisFunction(F)) |
| return false; |
| |
| vector<Instruction*> valuesStoredInFunction; |
| vector<BasicBlock*> exitBlocks; |
| |
| // Insert code to trace values at function entry |
| InsertCodeToShowFunctionEntry(F, externalFuncs.PrintfFunc, |
| externalFuncs.HashPtrFunc); |
| |
| // Push a pointer set for recording alloca'd pointers at entry. |
| if (!DisablePtrHashing) |
| new CallInst(externalFuncs.PushOnEntryFunc, vector<Value*>(), "", |
| F.getEntryNode().begin()); |
| |
| for (Function::iterator BB = F.begin(); BB != F.end(); ++BB) { |
| if (isa<ReturnInst>(BB->getTerminator())) |
| exitBlocks.push_back(BB); // record this as an exit block |
| |
| // Insert trace code if this basic block is interesting... |
| handleBasicBlock(BB, valuesStoredInFunction); |
| |
| if (!DisablePtrHashing) // release seq. numbers on free/ret |
| ReleasePtrSeqNumbers(BB, externalFuncs); |
| } |
| |
| for (unsigned i=0; i != exitBlocks.size(); ++i) |
| { |
| // Insert code to trace values at function exit |
| InsertCodeToShowFunctionExit(exitBlocks[i], externalFuncs.PrintfFunc, |
| externalFuncs.HashPtrFunc); |
| |
| // Release all recorded pointers before RETURN. Do this LAST! |
| if (!DisablePtrHashing) |
| new CallInst(externalFuncs.ReleaseOnReturnFunc, vector<Value*>(), "", |
| exitBlocks[i]->getTerminator()); |
| } |
| |
| return true; |
| } |