Implement basic block extraction for the miscompilation debugger. This still needs
two things: the FIXME in ExtractBlocks needs to be implemented, and the basic block
extractor itself needs to have enough bugs fixed for this to be more or less
useful.
Until the time that this is generally useful, it is hidden behind the new bugpoint
-enable-block-extraction option. I hope to get the FIXME done tonight.
Also of note, this patch adds a -extract-bbs option to bugpoint which can be used
to debug the block extractor. (hint hint Misha :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13471 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/bugpoint/ExtractFunction.cpp b/tools/bugpoint/ExtractFunction.cpp
index 9f8dca8..ecc2652 100644
--- a/tools/bugpoint/ExtractFunction.cpp
+++ b/tools/bugpoint/ExtractFunction.cpp
@@ -22,6 +22,7 @@
#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 "Support/CommandLine.h"
#include "Support/Debug.h"
@@ -199,3 +200,69 @@
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 Pass {
+ bool run(Module &M);
+ };
+ RegisterOpt<BlockExtractorPass>
+ XX("extract-bbs", "Extract Basic Blocks From Module (for bugpoint use)");
+}
+
+bool BlockExtractorPass::run(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";
+ return Ret;
+}