llvm-6502/lib/Transforms/Instrumentation/TraceValues.cpp
Chris Lattner 96c466b06a Add new optional getPassName() virtual function that a Pass can override
to make debugging output a lot nicer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2395 91177308-0d34-0410-b5e6-96231b3b80d8
2002-04-29 14:57:45 +00:00

311 lines
11 KiB
C++

//===- 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/TraceValues.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/iMemory.h"
#include "llvm/iTerminators.h"
#include "llvm/iOther.h"
#include "llvm/BasicBlock.h"
#include "llvm/Function.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
#include "llvm/Assembly/Writer.h"
#include "Support/StringExtras.h"
#include <sstream>
using std::vector;
using std::string;
namespace {
class InsertTraceCode : public FunctionPass {
bool TraceBasicBlockExits, TraceFunctionExits;
Function *PrintfFunc;
public:
InsertTraceCode(bool traceBasicBlockExits, bool traceFunctionExits)
: TraceBasicBlockExits(traceBasicBlockExits),
TraceFunctionExits(traceFunctionExits) {}
const char *getPassName() const { return "Trace Code Insertion"; }
// Add a prototype for printf if it is 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'.
//
static bool doit(Function *M, bool traceBasicBlockExits,
bool traceFunctionExits, Function *Printf);
// runOnFunction - This method does the work.
//
bool runOnFunction(Function *F) {
return doit(F, TraceBasicBlockExits, TraceFunctionExits, PrintfFunc);
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.preservesCFG();
}
};
} // end anonymous namespace
Pass *createTraceValuesPassForFunction() { // Just trace functions
return new InsertTraceCode(false, true);
}
Pass *createTraceValuesPassForBasicBlocks() { // Trace BB's and functions
return new InsertTraceCode(true, true);
}
// Add a prototype for printf if it is not already in the program.
//
bool InsertTraceCode::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);
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, true, 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.
//
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::FirstOtherOp &&
opCode != Instruction::Alloca &&
opCode != Instruction::PHINode &&
opCode != Instruction::Cast);
}
static bool ShouldTraceValue(const Instruction *I) {
return
I->getType() != Type::VoidTy && LiveAtBBExit(I) &&
TraceThisOpCode(I->getOpcode());
}
static string getPrintfCodeFor(const Value *V) {
if (V == 0) return "";
if (V->getType()->isFloatingPoint())
return "%g";
else if (V->getType() == Type::LabelTy || isa<PointerType>(V->getType()))
return "0x%p";
else if (V->getType()->isIntegral() || V->getType() == Type::BoolTy)
return "%d";
assert(0 && "Illegal value to print out...");
return "";
}
static void InsertPrintInst(Value *V, BasicBlock *BB, BasicBlock::iterator &BBI,
string Message, Function *Printf) {
// Escape Message by replacing all % characters with %% chars.
unsigned Offset = 0;
while ((Offset = Message.find('%', Offset)) != string::npos) {
Message.replace(Offset, 1, "%%");
Offset += 2; // Skip over the new %'s
}
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 *
Instruction *GEP =
new GetElementPtrInst(fmtVal,
vector<Value*>(2,ConstantUInt::get(Type::UIntTy, 0)),
"trstr");
BBI = BB->getInstList().insert(BBI, GEP)+1;
// Insert the first print instruction to print the string flag:
vector<Value*> PrintArgs;
PrintArgs.push_back(GEP);
if (V) PrintArgs.push_back(V);
Instruction *I = new CallInst(Printf, PrintArgs, "trace");
BBI = BB->getInstList().insert(BBI, I)+1;
}
static void InsertVerbosePrintInst(Value *V, BasicBlock *BB,
BasicBlock::iterator &BBI,
const string &Message, Function *Printf) {
std::ostringstream OutStr;
if (V) WriteAsOperand(OutStr, V);
InsertPrintInst(V, BB, BBI, Message+OutStr.str()+" = ", Printf);
}
// Insert print instructions at the end of the basic block *bb
// for each value in valueVec[] that is live at the end of that basic block,
// or that is stored to memory in this basic block.
// If the value is stored to memory, we load it back before printing
// 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).
// *bb must be the block in which the value is computed;
// this is not checked here.
//
static void TraceValuesAtBBExit(BasicBlock *BB, Function *Printf,
vector<Instruction*> *valuesStoredInFunction) {
// Get an iterator to point to the insertion location, which is
// just before the terminator instruction.
//
BasicBlock::iterator InsertPos = BB->end()-1;
assert((*InsertPos)->isTerminator());
// If the terminator is a conditional branch, insert the trace code just
// before the instruction that computes the branch condition (just to
// avoid putting a call between the CC-setting instruction and the branch).
// Use laterInstrSet to mark instructions that come after the setCC instr
// because those cannot be traced at the location we choose.
//
Instruction *SetCC = 0;
if (BranchInst *Branch = dyn_cast<BranchInst>(BB->getTerminator()))
if (!Branch->isUnconditional())
if (Instruction *I = dyn_cast<Instruction>(Branch->getCondition()))
if (I->getParent() == BB) {
SetCC = I;
while (*InsertPos != SetCC)
--InsertPos; // Back up until we can insert before the setcc
}
// Copy all of the instructions into a vector to avoid problems with Setcc
const vector<Instruction*> Insts(BB->begin(), InsertPos);
std::ostringstream OutStr;
WriteAsOperand(OutStr, BB, false);
InsertPrintInst(0, BB, InsertPos, "LEAVING BB:" + OutStr.str(), Printf);
// Insert a print instruction for each value.
//
for (vector<Instruction*>::const_iterator II = Insts.begin(),
IE = Insts.end(); II != IE; ++II) {
Instruction *I = *II;
if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
assert(valuesStoredInFunction &&
"Should not be printing a store instruction at function exit");
LoadInst *LI = new LoadInst(SI->getPointerOperand(), SI->copyIndices(),
"reload");
InsertPos = BB->getInstList().insert(InsertPos, LI) + 1;
valuesStoredInFunction->push_back(LI);
}
if (ShouldTraceValue(I))
InsertVerbosePrintInst(I, BB, InsertPos, " ", Printf);
}
}
static inline void InsertCodeToShowFunctionEntry(Function *M, Function *Printf){
// Get an iterator to point to the insertion location
BasicBlock *BB = M->getEntryNode();
BasicBlock::iterator BBI = BB->begin();
std::ostringstream OutStr;
WriteAsOperand(OutStr, M, true);
InsertPrintInst(0, BB, BBI, "ENTERING FUNCTION: " + OutStr.str(), Printf);
// Now print all the incoming arguments
const Function::ArgumentListType &argList = M->getArgumentList();
unsigned ArgNo = 0;
for (Function::ArgumentListType::const_iterator
I = argList.begin(), E = argList.end(); I != E; ++I, ++ArgNo) {
InsertVerbosePrintInst((Value*)*I, BB, BBI,
" Arg #" + utostr(ArgNo), Printf);
}
}
static inline void InsertCodeToShowFunctionExit(BasicBlock *BB,
Function *Printf) {
// Get an iterator to point to the insertion location
BasicBlock::iterator BBI = BB->end()-1;
ReturnInst *Ret = cast<ReturnInst>(*BBI);
std::ostringstream OutStr;
WriteAsOperand(OutStr, BB->getParent(), true);
InsertPrintInst(0, BB, BBI, "LEAVING FUNCTION: " + OutStr.str(), Printf);
// print the return value, if any
if (BB->getParent()->getReturnType() != Type::VoidTy)
InsertPrintInst(Ret->getReturnValue(), BB, BBI, " Returning: ", Printf);
}
bool InsertTraceCode::doit(Function *M, bool traceBasicBlockExits,
bool traceFunctionEvents, Function *Printf) {
if (!traceBasicBlockExits && !traceFunctionEvents)
return false;
vector<Instruction*> valuesStoredInFunction;
vector<BasicBlock*> exitBlocks;
if (traceFunctionEvents)
InsertCodeToShowFunctionEntry(M, Printf);
for (Function::iterator BI = M->begin(); BI != M->end(); ++BI) {
BasicBlock *BB = *BI;
if (isa<ReturnInst>(BB->getTerminator()))
exitBlocks.push_back(BB); // record this as an exit block
if (traceBasicBlockExits)
TraceValuesAtBBExit(BB, Printf, &valuesStoredInFunction);
}
if (traceFunctionEvents)
for (unsigned i=0; i < exitBlocks.size(); ++i) {
#if 0
TraceValuesAtBBExit(valuesStoredInFunction, exitBlocks[i], module,
/*indent*/ 0, /*isFunctionExit*/ true,
/*valuesStoredInFunction*/ NULL);
#endif
InsertCodeToShowFunctionExit(exitBlocks[i], Printf);
}
return true;
}