//===- 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 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.
+// 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/Assembly/Writer.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+#include "llvm/PassManager.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/FileUtilities.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/ToolOutputFile.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 "llvm/Transforms/Utils/CodeExtractor.h"
+#include <set>
using namespace llvm;
namespace llvm {
bool DisableSimplifyCFG = false;
+ extern cl::opt<std::string> OutputPrefix;
} // End llvm namespace
namespace {
cl::opt<bool>
- NoADCE("disable-adce",
- cl::desc("Do not use the -adce pass to reduce testcases"));
- 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"));
-}
+
+ Function* globalInitUsesExternalBA(GlobalVariable* GV) {
+ if (!GV->hasInitializer())
+ return 0;
+
+ Constant *I = GV->getInitializer();
+
+ // walk the values used by the initializer
+ // (and recurse into things like ConstantExpr)
+ std::vector<Constant*> Todo;
+ std::set<Constant*> Done;
+ Todo.push_back(I);
+
+ while (!Todo.empty()) {
+ Constant* V = Todo.back();
+ Todo.pop_back();
+ Done.insert(V);
+
+ if (BlockAddress *BA = dyn_cast<BlockAddress>(V)) {
+ Function *F = BA->getFunction();
+ if (F->isDeclaration())
+ return F;
+ }
+
+ for (User::op_iterator i = V->op_begin(), e = V->op_end(); i != e; ++i) {
+ Constant *C = dyn_cast<Constant>(*i);
+ if (C && !isa<GlobalValue>(C) && !Done.count(C))
+ Todo.push_back(C);
+ }
+ }
+ return 0;
+ }
+} // end anonymous namespace
/// 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);
+Module *BugDriver::deleteInstructionFromProgram(const Instruction *I,
+ unsigned Simplification) {
+ // FIXME, use vmap?
+ Module *Clone = CloneModule(Program);
- BasicBlock *PBB = I->getParent();
- Function *PF = PBB->getParent();
+ 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(Program->begin(), Module::iterator(PF)));
+ Module::iterator RFI = Clone->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::iterator(PBB)));
+ 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::iterator(I)));
- I = RI; // Got the corresponding instruction!
+ 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 (I->getType() != Type::VoidTy)
- I->replaceAllUsesWith(Constant::getNullValue(I->getType()));
+ if (!TheInst->getType()->isVoidTy())
+ TheInst->replaceAllUsesWith(Constant::getNullValue(TheInst->getType()));
// Remove the instruction from the program.
- I->getParent()->getInstList().erase(I);
+ TheInst->getParent()->getInstList().erase(TheInst);
// 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));
+ std::vector<std::string> Passes;
- if (Simplification > 2 && !NoADCE)
- Passes.add(createAggressiveDCEPass()); // Remove dead code...
- //Passes.add(createInstructionCombiningPass());
+ /// Can we get rid of the -disable-* options?
if (Simplification > 1 && !NoDCE)
- Passes.add(createDeadCodeEliminationPass());
+ Passes.push_back("dce");
if (Simplification && !DisableSimplifyCFG)
- Passes.add(createCFGSimplificationPass()); // Delete dead control flow
-
- Passes.add(createVerifierPass());
- Passes.run(*Result);
- return Result;
-}
+ Passes.push_back("simplifycfg"); // Delete dead control flow
-static const PassInfo *getPI(Pass *P) {
- const PassInfo *PI = P->getPassInfo();
- delete P;
- return PI;
+ Passes.push_back("verify");
+ Module *New = runPassesOn(Clone, Passes);
+ delete Clone;
+ if (!New) {
+ errs() << "Instruction removal failed. Sorry. :( Please report a bug!\n";
+ exit(1);
+ }
+ return New;
}
/// 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...
+/// 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()));
+
+ std::vector<std::string> CleanupPasses;
+ CleanupPasses.push_back("globaldce");
if (MayModifySemantics)
- CleanupPasses.push_back(getPI(createDeadArgHackingPass()));
+ CleanupPasses.push_back("deadarghaX0r");
else
- CleanupPasses.push_back(getPI(createDeadArgEliminationPass()));
-
- std::swap(Program, M);
- std::string Filename;
- bool Failed = runPasses(CleanupPasses, Filename);
- std::swap(Program, M);
+ CleanupPasses.push_back("deadargelim");
+
+ Module *New = runPassesOn(M, CleanupPasses);
+ if (New == 0) {
+ errs() << "Final cleanups failed. Sorry. :( Please report a bug!\n";
+ return M;
+ }
+ delete M;
+ return New;
+}
- if (Failed) {
- std::cerr << "Final cleanups failed. Sorry. :(\n";
+
+/// 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<std::string> LoopExtractPasses;
+ LoopExtractPasses.push_back("loop-extract-single");
+
+ Module *NewM = runPassesOn(M, LoopExtractPasses);
+ if (NewM == 0) {
+ outs() << "*** Loop extraction failed: ";
+ EmitProgressBitcode(M, "loopextraction", true);
+ outs() << "*** Sorry. :( Please report a bug!\n";
+ 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 {
- delete M;
- M = ParseInputFile(Filename);
- if (M == 0) {
- std::cerr << getToolName() << ": Error reading bytecode file '"
- << Filename << "'!\n";
- exit(1);
+ 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;
+ Type *Int32Ty = Type::getInt32Ty(TorList[0].first->getContext());
+
+ StructType *STy =
+ StructType::get(Int32Ty, TorList[0].first->getType(), NULL);
+ for (unsigned i = 0, e = TorList.size(); i != e; ++i) {
+ Constant *Elts[] = {
+ ConstantInt::get(Int32Ty, TorList[i].second),
+ TorList[i].first
+ };
+ ArrayElts.push_back(ConstantStruct::get(STy, 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,
+ ValueToValueMapTy &VMap) {
+ GlobalVariable *GV = M1->getNamedGlobal(GlobalName);
+ if (!GV || GV->isDeclaration() || GV->hasLocalLinkage() ||
+ !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 = cast<Function>(VMap[F]);
+ M2Tors.push_back(std::make_pair(F, Priority));
+ }
+ }
+ }
+ }
+
+ GV->eraseFromParent();
+ if (!M1Tors.empty()) {
+ Constant *M1Init = GetTorInit(M1Tors);
+ new GlobalVariable(*M1, M1Init->getType(), false,
+ GlobalValue::AppendingLinkage,
+ M1Init, GlobalName);
+ }
+
+ 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(*M2, M2Init->getType(), false,
+ GlobalValue::AppendingLinkage,
+ M2Init, GlobalName);
+ }
+}
+
+
+/// 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,
+ ValueToValueMapTy &VMap) {
+ // 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) {
+ if (I->hasName() && I->getName()[0] == '\01')
+ I->setName(I->getName().substr(1));
+ I->setLinkage(GlobalValue::ExternalLinkage);
+ }
+
+ ValueToValueMapTy NewVMap;
+ Module *New = CloneModule(M, NewVMap);
+
+ // Remove the Test functions from the Safe module
+ std::set<Function *> TestFunctions;
+ for (unsigned i = 0, e = F.size(); i != e; ++i) {
+ Function *TNOF = cast<Function>(VMap[F[i]]);
+ DEBUG(errs() << "Removing function ");
+ DEBUG(WriteAsOperand(errs(), TNOF, false));
+ DEBUG(errs() << "\n");
+ TestFunctions.insert(cast<Function>(NewVMap[TNOF]));
+ 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(I))
+ DeleteFunctionBody(I);
+
+
+ // Try to split the global initializers evenly
+ for (Module::global_iterator I = M->global_begin(), E = M->global_end();
+ I != E; ++I) {
+ GlobalVariable *GV = cast<GlobalVariable>(NewVMap[I]);
+ if (Function *TestFn = globalInitUsesExternalBA(I)) {
+ if (Function *SafeFn = globalInitUsesExternalBA(GV)) {
+ errs() << "*** Error: when reducing functions, encountered "
+ "the global '";
+ WriteAsOperand(errs(), GV, false);
+ errs() << "' with an initializer that references blockaddresses "
+ "from safe function '" << SafeFn->getName()
+ << "' and from test function '" << TestFn->getName() << "'.\n";
+ exit(1);
+ }
+ I->setInitializer(0); // Delete the initializer to make it external
+ } else {
+ // If we keep it in the safe module, then delete it in the test module
+ GV->setInitializer(0);
}
}
- return M;
+
+ // 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, NewVMap);
+ SplitStaticCtorDtor("llvm.global_dtors", M, New, NewVMap);
+
+ return New;
+}
+
+//===----------------------------------------------------------------------===//
+// Basic Block Extraction Code
+//===----------------------------------------------------------------------===//
+
+/// 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) {
+ SmallString<128> Filename;
+ int FD;
+ error_code EC = sys::fs::createUniqueFile(
+ OutputPrefix + "-extractblocks%%%%%%%", FD, Filename);
+ if (EC) {
+ outs() << "*** Basic Block extraction failed!\n";
+ errs() << "Error creating temporary file: " << EC.message() << "\n";
+ EmitProgressBitcode(M, "basicblockextractfail", true);
+ return 0;
+ }
+ sys::RemoveFileOnSignal(Filename);
+
+ tool_output_file BlocksToNotExtractFile(Filename.c_str(), FD);
+ for (std::vector<BasicBlock*>::const_iterator I = BBs.begin(), E = BBs.end();
+ I != E; ++I) {
+ BasicBlock *BB = *I;
+ // If the BB doesn't have a name, give it one so we have something to key
+ // off of.
+ if (!BB->hasName()) BB->setName("tmpbb");
+ BlocksToNotExtractFile.os() << BB->getParent()->getName() << " "
+ << BB->getName() << "\n";
+ }
+ BlocksToNotExtractFile.os().close();
+ if (BlocksToNotExtractFile.os().has_error()) {
+ errs() << "Error writing list of blocks to not extract\n";
+ EmitProgressBitcode(M, "basicblockextractfail", true);
+ BlocksToNotExtractFile.os().clear_error();
+ return 0;
+ }
+ BlocksToNotExtractFile.keep();
+
+ std::string uniqueFN = "--extract-blocks-file=";
+ uniqueFN += Filename.str();
+ const char *ExtraArg = uniqueFN.c_str();
+
+ std::vector<std::string> PI;
+ PI.push_back("extract-blocks");
+ Module *Ret = runPassesOn(M, PI, false, 1, &ExtraArg);
+
+ sys::fs::remove(Filename.c_str());
+
+ if (Ret == 0) {
+ outs() << "*** Basic Block extraction failed, please report a bug!\n";
+ EmitProgressBitcode(M, "basicblockextractfail", true);
+ }
+ return Ret;
}