1 files changed, 280 insertions, 0 deletions
diff --git a/tools/bugpoint/ExtractFunction.cpp b/tools/bugpoint/ExtractFunction.cpp
new file mode 100644
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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/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/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>
+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);
+
+  // 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));
+
+  /// 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";
+    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: ";
+    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.  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->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::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(), 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;
+}
+
+//===----------------------------------------------------------------------===//
+// 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);
+  };
+  RegisterOpt<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(), F->getFunctionType());
+
+    // 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);
+    EmitProgressBytecode("basicblockextractfail", true);
+    M = swapProgramIn(M);
+  }
+  return Ret;
+}