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diff --git a/llvm/tools/bugpoint/ExtractFunction.cpp b/llvm/tools/bugpoint/ExtractFunction.cpp
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+//===- ExtractFunction.cpp - Extract a function from Program --------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// 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/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Pass.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/Transforms/Utils/CodeExtractor.h"
+#include <set>
+using namespace llvm;
+
+#define DEBUG_TYPE "bugpoint"
+
+namespace llvm {
+bool DisableSimplifyCFG = false;
+extern cl::opt<std::string> OutputPrefix;
+} // 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"));
+
+Function *globalInitUsesExternalBA(GlobalVariable *GV) {
+ if (!GV->hasInitializer())
+ return nullptr;
+
+ 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 nullptr;
+}
+} // end anonymous namespace
+
+std::unique_ptr<Module>
+BugDriver::deleteInstructionFromProgram(const Instruction *I,
+ unsigned Simplification) {
+ // FIXME, use vmap?
+ std::unique_ptr<Module> Clone = CloneModule(*Program);
+
+ const BasicBlock *PBB = I->getParent();
+ const Function *PF = PBB->getParent();
+
+ 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::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()->isVoidTy())
+ TheInst->replaceAllUsesWith(Constant::getNullValue(TheInst->getType()));
+
+ // Remove the instruction from the program.
+ TheInst->getParent()->getInstList().erase(TheInst);
+
+ // Spiff up the output a little bit.
+ std::vector<std::string> Passes;
+
+ /// Can we get rid of the -disable-* options?
+ if (Simplification > 1 && !NoDCE)
+ Passes.push_back("dce");
+ if (Simplification && !DisableSimplifyCFG)
+ Passes.push_back("simplifycfg"); // Delete dead control flow
+
+ Passes.push_back("verify");
+ std::unique_ptr<Module> New = runPassesOn(Clone.get(), Passes);
+ if (!New) {
+ errs() << "Instruction removal failed. Sorry. :( Please report a bug!\n";
+ exit(1);
+ }
+ return New;
+}
+
+std::unique_ptr<Module>
+BugDriver::performFinalCleanups(std::unique_ptr<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<std::string> CleanupPasses;
+ CleanupPasses.push_back("globaldce");
+
+ if (MayModifySemantics)
+ CleanupPasses.push_back("deadarghaX0r");
+ else
+ CleanupPasses.push_back("deadargelim");
+
+ std::unique_ptr<Module> New = runPassesOn(M.get(), CleanupPasses);
+ if (!New) {
+ errs() << "Final cleanups failed. Sorry. :( Please report a bug!\n";
+ return nullptr;
+ }
+ return New;
+}
+
+std::unique_ptr<Module> BugDriver::extractLoop(Module *M) {
+ std::vector<std::string> LoopExtractPasses;
+ LoopExtractPasses.push_back("loop-extract-single");
+
+ std::unique_ptr<Module> NewM = runPassesOn(M, LoopExtractPasses);
+ if (!NewM) {
+ outs() << "*** Loop extraction failed: ";
+ EmitProgressBitcode(*M, "loopextraction", true);
+ outs() << "*** Sorry. :( Please report a bug!\n";
+ return nullptr;
+ }
+
+ // 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) {
+ return nullptr;
+ } 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;
+}
+
+static void eliminateAliases(GlobalValue *GV) {
+ // First, check whether a GlobalAlias references this definition.
+ // GlobalAlias MAY NOT reference declarations.
+ for (;;) {
+ // 1. Find aliases
+ SmallVector<GlobalAlias *, 1> aliases;
+ Module *M = GV->getParent();
+ for (Module::alias_iterator I = M->alias_begin(), E = M->alias_end();
+ I != E; ++I)
+ if (I->getAliasee()->stripPointerCasts() == GV)
+ aliases.push_back(&*I);
+ if (aliases.empty())
+ break;
+ // 2. Resolve aliases
+ for (unsigned i = 0, e = aliases.size(); i < e; ++i) {
+ aliases[i]->replaceAllUsesWith(aliases[i]->getAliasee());
+ aliases[i]->eraseFromParent();
+ }
+ // 3. Repeat until no more aliases found; there might
+ // be an alias to an alias...
+ }
+}
+
+//
+// DeleteGlobalInitializer - "Remove" the global variable by deleting its
+// initializer,
+// making it external.
+//
+void llvm::DeleteGlobalInitializer(GlobalVariable *GV) {
+ eliminateAliases(GV);
+ GV->setInitializer(nullptr);
+ GV->setComdat(nullptr);
+}
+
+// DeleteFunctionBody - "Remove" the function by deleting all of its basic
+// blocks, making it external.
+//
+void llvm::DeleteFunctionBody(Function *F) {
+ eliminateAliases(F);
+ // Function declarations can't have comdats.
+ F->setComdat(nullptr);
+
+ // 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());
+ 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);
+ }
+}
+
+std::unique_ptr<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;
+ std::unique_ptr<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]]);
+ LLVM_DEBUG(errs() << "Removing function ");
+ LLVM_DEBUG(TNOF->printAsOperand(errs(), false));
+ LLVM_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 (Function &I : *New)
+ if (!TestFunctions.count(&I))
+ DeleteFunctionBody(&I);
+
+ // Try to split the global initializers evenly
+ for (GlobalVariable &I : M->globals()) {
+ GlobalVariable *GV = cast<GlobalVariable>(NewVMap[&I]);
+ if (Function *TestFn = globalInitUsesExternalBA(&I)) {
+ if (Function *SafeFn = globalInitUsesExternalBA(GV)) {
+ errs() << "*** Error: when reducing functions, encountered "
+ "the global '";
+ GV->printAsOperand(errs(), false);
+ errs() << "' with an initializer that references blockaddresses "
+ "from safe function '"
+ << SafeFn->getName() << "' and from test function '"
+ << TestFn->getName() << "'.\n";
+ exit(1);
+ }
+ DeleteGlobalInitializer(&I); // Delete the initializer to make it external
+ } else {
+ // If we keep it in the safe module, then delete it in the test module
+ DeleteGlobalInitializer(GV);
+ }
+ }
+
+ // 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.get(), NewVMap);
+ SplitStaticCtorDtor("llvm.global_dtors", M, New.get(), NewVMap);
+
+ return New;
+}
+
+//===----------------------------------------------------------------------===//
+// Basic Block Extraction Code
+//===----------------------------------------------------------------------===//
+
+std::unique_ptr<Module>
+BugDriver::extractMappedBlocksFromModule(const std::vector<BasicBlock *> &BBs,
+ Module *M) {
+ auto Temp = sys::fs::TempFile::create(OutputPrefix + "-extractblocks%%%%%%%");
+ if (!Temp) {
+ outs() << "*** Basic Block extraction failed!\n";
+ errs() << "Error creating temporary file: " << toString(Temp.takeError())
+ << "\n";
+ EmitProgressBitcode(*M, "basicblockextractfail", true);
+ return nullptr;
+ }
+ DiscardTemp Discard{*Temp};
+
+ // Extract all of the blocks except the ones in BBs.
+ SmallVector<BasicBlock *, 32> BlocksToExtract;
+ for (Function &F : *M)
+ for (BasicBlock &BB : F)
+ // Check if this block is going to be extracted.
+ if (std::find(BBs.begin(), BBs.end(), &BB) == BBs.end())
+ BlocksToExtract.push_back(&BB);
+
+ raw_fd_ostream OS(Temp->FD, /*shouldClose*/ false);
+ for (BasicBlock *BB : BBs) {
+ // 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");
+ OS << BB->getParent()->getName() << " " << BB->getName() << "\n";
+ }
+ OS.flush();
+ if (OS.has_error()) {
+ errs() << "Error writing list of blocks to not extract\n";
+ EmitProgressBitcode(*M, "basicblockextractfail", true);
+ OS.clear_error();
+ return nullptr;
+ }
+
+ std::string uniqueFN = "--extract-blocks-file=";
+ uniqueFN += Temp->TmpName;
+
+ std::vector<std::string> PI;
+ PI.push_back("extract-blocks");
+ std::unique_ptr<Module> Ret = runPassesOn(M, PI, {uniqueFN});
+
+ if (!Ret) {
+ outs() << "*** Basic Block extraction failed, please report a bug!\n";
+ EmitProgressBitcode(*M, "basicblockextractfail", true);
+ }
+ return Ret;
+}
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