[llvm-extract] Support extracting basic blocks

Summary:
Currently, there is no way to extract a basic block from a function easily. This patch
extends llvm-extract to extract the specified basic block(s).

Reviewers: loladiro, rafael, bogner

Reviewed By: bogner

Subscribers: hintonda, mgorny, qcolombet, llvm-commits

Differential Revision: https://reviews.llvm.org/D41638

llvm-svn: 323266

1 files changed, 0 insertions, 152 deletions

diff --git a/llvm/lib/Transforms/IPO/LoopExtractor.cpp b/llvm/lib/Transforms/IPO/LoopExtractor.cpp
index 36b6bdba2cd..6964235df06 100644
--- a/llvm/lib/Transforms/IPO/LoopExtractor.cpp
+++ b/llvm/lib/Transforms/IPO/LoopExtractor.cpp
@@ -158,155 +158,3 @@ bool LoopExtractor::runOnLoop(Loop *L, LPPassManager &LPM) {
 Pass *llvm::createSingleLoopExtractorPass() {
   return new SingleLoopExtractor();
 }
-
-
-// BlockFile - A file which contains a list of blocks that should not be
-// extracted.
-static cl::opt<std::string>
-BlockFile("extract-blocks-file", cl::value_desc("filename"),
-          cl::desc("A file containing list of basic blocks to not extract"),
-          cl::Hidden);
-
-namespace {
-  /// 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 {
-    void LoadFile(const char *Filename);
-    void SplitLandingPadPreds(Function *F);
-
-    std::vector<BasicBlock*> BlocksToNotExtract;
-    std::vector<std::pair<std::string, std::string> > BlocksToNotExtractByName;
-  public:
-    static char ID; // Pass identification, replacement for typeid
-    BlockExtractorPass() : ModulePass(ID) {
-      if (!BlockFile.empty())
-        LoadFile(BlockFile.c_str());
-    }
-
-    bool runOnModule(Module &M) override;
-  };
-}
-
-char BlockExtractorPass::ID = 0;
-INITIALIZE_PASS(BlockExtractorPass, "extract-blocks",
-                "Extract Basic Blocks From Module (for bugpoint use)",
-                false, false)
-
-// createBlockExtractorPass - This pass extracts all blocks (except those
-// specified in the argument list) from the functions in the module.
-//
-ModulePass *llvm::createBlockExtractorPass() {
-  return new BlockExtractorPass();
-}
-
-void BlockExtractorPass::LoadFile(const char *Filename) {
-  // Load the BlockFile...
-  std::ifstream In(Filename);
-  if (!In.good()) {
-    errs() << "WARNING: BlockExtractor couldn't load file '" << Filename
-           << "'!\n";
-    return;
-  }
-  while (In) {
-    std::string FunctionName, BlockName;
-    In >> FunctionName;
-    In >> BlockName;
-    if (!BlockName.empty())
-      BlocksToNotExtractByName.push_back(
-          std::make_pair(FunctionName, BlockName));
-  }
-}
-
-/// SplitLandingPadPreds - The landing pad needs to be extracted with the invoke
-/// instruction. The critical edge breaker will refuse to break critical edges
-/// to a landing pad. So do them here. After this method runs, all landing pads
-/// should have only one predecessor.
-void BlockExtractorPass::SplitLandingPadPreds(Function *F) {
-  for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
-    InvokeInst *II = dyn_cast<InvokeInst>(I);
-    if (!II) continue;
-    BasicBlock *Parent = II->getParent();
-    BasicBlock *LPad = II->getUnwindDest();
-
-    // Look through the landing pad's predecessors. If one of them ends in an
-    // 'invoke', then we want to split the landing pad.
-    bool Split = false;
-    for (pred_iterator
-           PI = pred_begin(LPad), PE = pred_end(LPad); PI != PE; ++PI) {
-      BasicBlock *BB = *PI;
-      if (BB->isLandingPad() && BB != Parent &&
-          isa<InvokeInst>(Parent->getTerminator())) {
-        Split = true;
-        break;
-      }
-    }
-
-    if (!Split) continue;
-
-    SmallVector<BasicBlock*, 2> NewBBs;
-    SplitLandingPadPredecessors(LPad, Parent, ".1", ".2", NewBBs);
-  }
-}
-
-bool BlockExtractorPass::runOnModule(Module &M) {
-  if (skipModule(M))
-    return false;
-
-  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());
-    assert(MF->getFunctionType() == F->getFunctionType() && "Wrong function?");
-
-    // 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);
-  }
-
-  while (!BlocksToNotExtractByName.empty()) {
-    // There's no way to find BBs by name without looking at every BB inside
-    // every Function. Fortunately, this is always empty except when used by
-    // bugpoint in which case correctness is more important than performance.
-
-    std::string &FuncName  = BlocksToNotExtractByName.back().first;
-    std::string &BlockName = BlocksToNotExtractByName.back().second;
-
-    for (Function &F : M) {
-      if (F.getName() != FuncName) continue;
-
-      for (BasicBlock &BB : F) {
-        if (BB.getName() != BlockName) continue;
-
-        TranslatedBlocksToNotExtract.insert(&BB);
-      }
-    }
-
-    BlocksToNotExtractByName.pop_back();
-  }
-
-  // Now that we know which blocks to not extract, figure out which ones we WANT
-  // to extract.
-  std::vector<BasicBlock*> BlocksToExtract;
-  for (Function &F : M) {
-    SplitLandingPadPreds(&F);
-    for (BasicBlock &BB : F)
-      if (!TranslatedBlocksToNotExtract.count(&BB))
-        BlocksToExtract.push_back(&BB);
-  }
-
-  for (BasicBlock *BlockToExtract : BlocksToExtract) {
-    SmallVector<BasicBlock*, 2> BlocksToExtractVec;
-    BlocksToExtractVec.push_back(BlockToExtract);
-    if (const InvokeInst *II =
-            dyn_cast<InvokeInst>(BlockToExtract->getTerminator()))
-      BlocksToExtractVec.push_back(II->getUnwindDest());
-    CodeExtractor(BlocksToExtractVec).extractCodeRegion();
-  }
-
-  return !BlocksToExtract.empty();
-}