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//===- ExtractFunction.cpp - Extract a function from Program --------------===//
// 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 implements a method that extracts a function from program, cleans
// it up, and returns it as a new module.
#include "BugDriver.h"
#include "llvm/Constant.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Pass.h"
#include "llvm/Type.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Target/TargetData.h"
#include "Support/CommandLine.h"
bool DisableSimplifyCFG = false;
namespace {
cl::desc("Do not use the -adce pass to reduce testcases"));
NoDCE ("disable-dce",
cl::desc("Do not use the -dce pass to reduce testcases"));
cl::opt<bool, true>
NoSCFG("disable-simplifycfg", cl::location(DisableSimplifyCFG),
cl::desc("Do not use the -simplifycfg pass to reduce testcases"));
cl::desc("Disable the final cleanup phase of narrowing"));
/// deleteInstructionFromProgram - This method clones the current Program and
/// deletes the specified instruction from the cloned module. It then runs a
/// series of cleanup passes (ADCE and SimplifyCFG) to eliminate any code which
/// depends on the value. The modified module is then returned.
Module *BugDriver::deleteInstructionFromProgram(Instruction *I,
unsigned Simplification) const {
Module *Result = CloneModule(Program);
BasicBlock *PBB = I->getParent();
Function *PF = PBB->getParent();
Module::iterator RFI = Result->begin(); // Get iterator to corresponding fn
std::advance(RFI, std::distance(Program->begin(), Module::iterator(PF)));
Function::iterator RBI = RFI->begin(); // Get iterator to corresponding BB
std::advance(RBI, std::distance(PF->begin(), Function::iterator(PBB)));
BasicBlock::iterator RI = RBI->begin(); // Get iterator to corresponding inst
std::advance(RI, std::distance(PBB->begin(), BasicBlock::iterator(I)));
I = RI; // Got the corresponding instruction!
// If this instruction produces a value, replace any users with null values
if (I->getType() != Type::VoidTy)
// Remove the instruction from the program.
// Spiff up the output a little bit.
PassManager Passes;
// Make sure that the appropriate target data is always used...
Passes.add(new TargetData("bugpoint", Result));
if (Simplification > 2 && !NoADCE)
Passes.add(createAggressiveDCEPass()); // Remove dead code...
if (Simplification > 1 && !NoDCE)
if (Simplification && !DisableSimplifyCFG)
Passes.add(createCFGSimplificationPass()); // Delete dead control flow
return Result;
/// performFinalCleanups - This method clones the current Program and performs
/// a series of cleanups intended to get rid of extra cruft on the module
/// before handing it to the user...
Module *BugDriver::performFinalCleanups(Module *InM) const {
Module *M = InM ? InM : CloneModule(Program);
// Allow disabling these passes if they crash bugpoint.
// FIXME: This should eventually run these passes in a pass list to prevent
// them from being able to crash bugpoint at all!
if (NoFinalCleanup) return M;
// Make all functions external, so GlobalDCE doesn't delete them...
for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
PassManager CleanupPasses;
// Make sure that the appropriate target data is always used...
CleanupPasses.add(new TargetData("bugpoint", M));
CleanupPasses.add(createDeadArgEliminationPass(InM == 0));
return M;