//===- ExtractFunction.cpp - Extract a function from Program --------------===//
+//
+// The LLVM Compiler Infrastructure
//
-// This file implements a method that extracts a function from program, cleans
-// it up, and returns it as a new module.
+// 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 several methods that are used to extract functions,
+// loops, or portions of a module from the rest of the 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"
+#include "Support/Debug.h"
+#include "Support/FileUtilities.h"
+#include <set>
+using namespace llvm;
+
+namespace llvm {
+ bool DisableSimplifyCFG = false;
+} // End llvm namespace
+
+namespace {
+ cl::opt<bool>
+ 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"));
+}
-/// extractFunctionFromModule - This method is used to extract the specified
-/// (non-external) function from the current program, slim down the module, and
-/// then return it. This does not modify Program at all, it modifies a copy,
-/// which it returns.
-Module *BugDriver::extractFunctionFromModule(Function *F) const {
+/// 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(const Instruction *I,
+ unsigned Simplification) const {
Module *Result = CloneModule(Program);
- // Translate from the old module to the new copied module...
- F = Result->getFunction(F->getName(), F->getFunctionType());
+ const BasicBlock *PBB = I->getParent();
+ const Function *PF = PBB->getParent();
+
+ Module::iterator RFI = Result->begin(); // Get iterator to corresponding fn
+ std::advance(RFI, std::distance(PF->getParent()->begin(),
+ Module::const_iterator(PF)));
+
+ Function::iterator RBI = RFI->begin(); // Get iterator to corresponding BB
+ std::advance(RBI, std::distance(PF->begin(), Function::const_iterator(PBB)));
+
+ BasicBlock::iterator RI = RBI->begin(); // Get iterator to corresponding inst
+ std::advance(RI, std::distance(PBB->begin(), BasicBlock::const_iterator(I)));
+ Instruction *TheInst = RI; // Got the corresponding instruction!
+
+ // If this instruction produces a value, replace any users with null values
+ if (TheInst->getType() != Type::VoidTy)
+ TheInst->replaceAllUsesWith(Constant::getNullValue(TheInst->getType()));
- // In addition to just parsing the input from GCC, we also want to spiff it up
- // a little bit. Do this now.
- //
+ // Remove the instruction from the program.
+ TheInst->getParent()->getInstList().erase(TheInst);
+
+ // Spiff up the output a little bit.
PassManager Passes;
- Passes.add(createFunctionExtractionPass(F)); // Extract the function
- Passes.add(createGlobalDCEPass()); // Delete unreachable globals
- Passes.add(createFunctionResolvingPass()); // Delete prototypes
- Passes.add(createDeadTypeEliminationPass()); // Remove dead types...
+ // Make sure that the appropriate target data is always used...
+ Passes.add(new TargetData("bugpoint", Result));
+
+ /// FIXME: If this used runPasses() like the methods below, we could get rid
+ /// of the -disable-* options!
+ if (Simplification > 1 && !NoDCE)
+ Passes.add(createDeadCodeEliminationPass());
+ if (Simplification && !DisableSimplifyCFG)
+ Passes.add(createCFGSimplificationPass()); // Delete dead control flow
+
+ Passes.add(createVerifierPass());
Passes.run(*Result);
return Result;
}
+
+static const PassInfo *getPI(Pass *P) {
+ const PassInfo *PI = P->getPassInfo();
+ delete P;
+ return PI;
+}
+
+/// 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 *M, bool MayModifySemantics) {
+ // Make all functions external, so GlobalDCE doesn't delete them...
+ for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+ I->setLinkage(GlobalValue::ExternalLinkage);
+
+ std::vector<const PassInfo*> CleanupPasses;
+ CleanupPasses.push_back(getPI(createFunctionResolvingPass()));
+ CleanupPasses.push_back(getPI(createGlobalDCEPass()));
+ CleanupPasses.push_back(getPI(createDeadTypeEliminationPass()));
+
+ if (MayModifySemantics)
+ CleanupPasses.push_back(getPI(createDeadArgHackingPass()));
+ else
+ CleanupPasses.push_back(getPI(createDeadArgEliminationPass()));
+
+ Module *New = runPassesOn(M, CleanupPasses);
+ if (New == 0) {
+ std::cerr << "Final cleanups failed. Sorry. :( Please report a bug!\n";
+ }
+ delete M;
+ return New;
+}
+
+
+/// ExtractLoop - Given a module, extract up to one loop from it into a new
+/// function. This returns null if there are no extractable loops in the
+/// program or if the loop extractor crashes.
+Module *BugDriver::ExtractLoop(Module *M) {
+ std::vector<const PassInfo*> LoopExtractPasses;
+ LoopExtractPasses.push_back(getPI(createSingleLoopExtractorPass()));
+
+ Module *NewM = runPassesOn(M, LoopExtractPasses);
+ if (NewM == 0) {
+ Module *Old = swapProgramIn(M);
+ std::cout << "*** Loop extraction failed: ";
+ EmitProgressBytecode("loopextraction", true);
+ std::cout << "*** Sorry. :( Please report a bug!\n";
+ swapProgramIn(Old);
+ return 0;
+ }
+
+ // Check to see if we created any new functions. If not, no loops were
+ // extracted and we should return null.
+ if (M->size() == NewM->size()) {
+ delete NewM;
+ return 0;
+ }
+
+ return NewM;
+}
+
+
+// DeleteFunctionBody - "Remove" the function by deleting all of its basic
+// blocks, making it external.
+//
+void llvm::DeleteFunctionBody(Function *F) {
+ // delete the body of the function...
+ F->deleteBody();
+ assert(F->isExternal() && "This didn't make the function external!");
+}
+
+/// SplitFunctionsOutOfModule - Given a module and a list of functions in the
+/// module, split the functions OUT of the specified module, and place them in
+/// the new module.
+///
+/// FIXME: this could be made DRAMATICALLY more efficient for large programs if
+/// we just MOVED functions from one module to the other, instead of cloning the
+/// whole module, then proceeding to delete an entire module's worth of stuff.
+///
+Module *llvm::SplitFunctionsOutOfModule(Module *M,
+ const std::vector<Function*> &F) {
+ // Make sure functions & globals are all external so that linkage
+ // between the two modules will work.
+ for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+ I->setLinkage(GlobalValue::ExternalLinkage);
+ for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+ I->setLinkage(GlobalValue::ExternalLinkage);
+
+ Module *New = CloneModule(M);
+
+ // Make sure global initializers exist only in the safe module (CBE->.so)
+ for (Module::giterator I = New->gbegin(), E = New->gend(); I != E; ++I)
+ I->setInitializer(0); // Delete the initializer to make it external
+
+ // Remove the Test functions from the Safe module
+ std::set<std::pair<std::string, const PointerType*> > TestFunctions;
+ for (unsigned i = 0, e = F.size(); i != e; ++i) {
+ TestFunctions.insert(std::make_pair(F[i]->getName(), F[i]->getType()));
+ Function *TNOF = M->getFunction(F[i]->getName(), F[i]->getFunctionType());
+ DEBUG(std::cerr << "Removing function " << F[i]->getName() << "\n");
+ assert(TNOF && "Function doesn't exist in module!");
+ DeleteFunctionBody(TNOF); // Function is now external in this module!
+ }
+
+ // Remove the Safe functions from the Test module
+ for (Module::iterator I = New->begin(), E = New->end(); I != E; ++I)
+ if (!TestFunctions.count(std::make_pair(I->getName(), I->getType())))
+ DeleteFunctionBody(I);
+ return New;
+}