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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 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/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+#include "llvm/PassManager.h"
+#include "llvm/Pass.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/Transforms/Utils/FunctionUtils.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/FileUtilities.h"
+#include <set>
+#include <iostream>
+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"));
+}
+
+/// 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);
+
+ 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()));
+
+ // Remove the instruction from the program.
+ TheInst->getParent()->getInstList().erase(TheInst);
+
+
+ //writeProgramToFile("current.bc", Result);
+
+ // Spiff up the output a little bit.
+ PassManager Passes;
+ // Make sure that the appropriate target data is always used...
+ Passes.add(new TargetData(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(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";
+ return M;
+ }
+ 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: ";
+ EmitProgressBitcode("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. Limit the number of loops we extract
+ // to avoid taking forever.
+ static unsigned NumExtracted = 32;
+ if (M->size() == NewM->size() || --NumExtracted == 0) {
+ delete NewM;
+ return 0;
+ } else {
+ assert(M->size() < NewM->size() && "Loop extract removed functions?");
+ Module::iterator MI = NewM->begin();
+ for (unsigned i = 0, e = M->size(); i != e; ++i)
+ ++MI;
+ }
+
+ 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->isDeclaration() && "This didn't make the function external!");
+}
+
+/// GetTorInit - Given a list of entries for static ctors/dtors, return them
+/// as a constant array.
+static Constant *GetTorInit(std::vector<std::pair<Function*, int> > &TorList) {
+ assert(!TorList.empty() && "Don't create empty tor list!");
+ std::vector<Constant*> ArrayElts;
+ for (unsigned i = 0, e = TorList.size(); i != e; ++i) {
+ std::vector<Constant*> Elts;
+ Elts.push_back(ConstantInt::get(Type::Int32Ty, TorList[i].second));
+ Elts.push_back(TorList[i].first);
+ ArrayElts.push_back(ConstantStruct::get(Elts));
+ }
+ return ConstantArray::get(ArrayType::get(ArrayElts[0]->getType(),
+ ArrayElts.size()),
+ ArrayElts);
+}
+
+/// SplitStaticCtorDtor - A module was recently split into two parts, M1/M2, and
+/// M1 has all of the global variables. If M2 contains any functions that are
+/// static ctors/dtors, we need to add an llvm.global_[cd]tors global to M2, and
+/// prune appropriate entries out of M1s list.
+static void SplitStaticCtorDtor(const char *GlobalName, Module *M1, Module *M2){
+ GlobalVariable *GV = M1->getNamedGlobal(GlobalName);
+ if (!GV || GV->isDeclaration() || GV->hasInternalLinkage() ||
+ !GV->use_empty()) return;
+
+ std::vector<std::pair<Function*, int> > M1Tors, M2Tors;
+ ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
+ if (!InitList) return;
+
+ for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
+ if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
+ if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
+
+ if (CS->getOperand(1)->isNullValue())
+ break; // Found a null terminator, stop here.
+
+ ConstantInt *CI = dyn_cast<ConstantInt>(CS->getOperand(0));
+ int Priority = CI ? CI->getSExtValue() : 0;
+
+ Constant *FP = CS->getOperand(1);
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(FP))
+ if (CE->isCast())
+ FP = CE->getOperand(0);
+ if (Function *F = dyn_cast<Function>(FP)) {
+ if (!F->isDeclaration())
+ M1Tors.push_back(std::make_pair(F, Priority));
+ else {
+ // Map to M2's version of the function.
+ F = M2->getFunction(F->getName());
+ M2Tors.push_back(std::make_pair(F, Priority));
+ }
+ }
+ }
+ }
+
+ GV->eraseFromParent();
+ if (!M1Tors.empty()) {
+ Constant *M1Init = GetTorInit(M1Tors);
+ new GlobalVariable(M1Init->getType(), false, GlobalValue::AppendingLinkage,
+ M1Init, GlobalName, M1);
+ }
+
+ GV = M2->getNamedGlobal(GlobalName);
+ assert(GV && "Not a clone of M1?");
+ assert(GV->use_empty() && "llvm.ctors shouldn't have uses!");
+
+ GV->eraseFromParent();
+ if (!M2Tors.empty()) {
+ Constant *M2Init = GetTorInit(M2Tors);
+ new GlobalVariable(M2Init->getType(), false, GlobalValue::AppendingLinkage,
+ M2Init, GlobalName, M2);
+ }
+}
+
+
+/// 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.
+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::global_iterator I = M->global_begin(), E = M->global_end();
+ 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::global_iterator I = New->global_begin(), E = New->global_end();
+ 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());
+ assert(TNOF && "Function doesn't exist in module!");
+ assert(TNOF->getFunctionType() == F[i]->getFunctionType() && "wrong type?");
+ DEBUG(std::cerr << "Removing function " << F[i]->getName() << "\n");
+ 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);
+
+
+ // Make sure that there is a global ctor/dtor array in both halves of the
+ // module if they both have static ctor/dtor functions.
+ SplitStaticCtorDtor("llvm.global_ctors", M, New);
+ SplitStaticCtorDtor("llvm.global_dtors", M, New);
+
+ return New;
+}
+
+//===----------------------------------------------------------------------===//
+// Basic Block Extraction Code
+//===----------------------------------------------------------------------===//
+
+namespace {
+ std::vector<BasicBlock*> BlocksToNotExtract;
+
+ /// BlockExtractorPass - This pass is used by bugpoint to extract all blocks
+ /// from the module into their own functions except for those specified by the
+ /// BlocksToNotExtract list.
+ class BlockExtractorPass : public ModulePass {
+ bool runOnModule(Module &M);
+ public:
+ static char ID; // Pass ID, replacement for typeid
+ BlockExtractorPass() : ModulePass((intptr_t)&ID) {}
+ };
+ char BlockExtractorPass::ID = 0;
+ RegisterPass<BlockExtractorPass>
+ XX("extract-bbs", "Extract Basic Blocks From Module (for bugpoint use)");
+}
+
+bool BlockExtractorPass::runOnModule(Module &M) {
+ std::set<BasicBlock*> TranslatedBlocksToNotExtract;
+ for (unsigned i = 0, e = BlocksToNotExtract.size(); i != e; ++i) {
+ BasicBlock *BB = BlocksToNotExtract[i];
+ Function *F = BB->getParent();
+
+ // Map the corresponding function in this module.
+ Function *MF = M.getFunction(F->getName());
+
+ // Figure out which index the basic block is in its function.
+ Function::iterator BBI = MF->begin();
+ std::advance(BBI, std::distance(F->begin(), Function::iterator(BB)));
+ TranslatedBlocksToNotExtract.insert(BBI);
+ }
+
+ // Now that we know which blocks to not extract, figure out which ones we WANT
+ // to extract.
+ std::vector<BasicBlock*> BlocksToExtract;
+ for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F)
+ for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
+ if (!TranslatedBlocksToNotExtract.count(BB))
+ BlocksToExtract.push_back(BB);
+
+ for (unsigned i = 0, e = BlocksToExtract.size(); i != e; ++i)
+ ExtractBasicBlock(BlocksToExtract[i]);
+
+ return !BlocksToExtract.empty();
+}
+
+/// ExtractMappedBlocksFromModule - Extract all but the specified basic blocks
+/// into their own functions. The only detail is that M is actually a module
+/// cloned from the one the BBs are in, so some mapping needs to be performed.
+/// If this operation fails for some reason (ie the implementation is buggy),
+/// this function should return null, otherwise it returns a new Module.
+Module *BugDriver::ExtractMappedBlocksFromModule(const
+ std::vector<BasicBlock*> &BBs,
+ Module *M) {
+ // Set the global list so that pass will be able to access it.
+ BlocksToNotExtract = BBs;
+
+ std::vector<const PassInfo*> PI;
+ PI.push_back(getPI(new BlockExtractorPass()));
+ Module *Ret = runPassesOn(M, PI);
+ BlocksToNotExtract.clear();
+ if (Ret == 0) {
+ std::cout << "*** Basic Block extraction failed, please report a bug!\n";
+ M = swapProgramIn(M);
+ EmitProgressBitcode("basicblockextractfail", true);
+ swapProgramIn(M);
+ }
+ return Ret;
+}
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