diff --git a/lib/Transforms/Utils/LowerInvoke.cpp b/lib/Transforms/Utils/LowerInvoke.cpp index eb3037fa92e..3a034ecd901 100644 --- a/lib/Transforms/Utils/LowerInvoke.cpp +++ b/lib/Transforms/Utils/LowerInvoke.cpp @@ -406,6 +406,7 @@ bool LowerInvoke::insertExpensiveEHSupport(Function &F) { SmallVector Returns; SmallVector Unwinds; SmallVector Invokes; + SmallVector Unreachables; for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) if (ReturnInst *RI = dyn_cast(BB->getTerminator())) { @@ -486,9 +487,10 @@ bool LowerInvoke::insertExpensiveEHSupport(Function &F) { // Insert a load in the Catch block, and a switch on its value. By default, // we go to a block that just does an unwind (which is the correct action - // for a standard call). + // for a standard call). We insert an unreachable instruction here and + // modify the block to jump to the correct unwinding pad later. BasicBlock *UnwindBB = BasicBlock::Create(F.getContext(), "unwindbb", &F); - Unwinds.push_back(new UnwindInst(F.getContext(), UnwindBB)); + Unreachables.push_back(new UnreachableInst(F.getContext(), UnwindBB)); Value *CatchLoad = new LoadInst(InvokeNum, "invoke.num", true, CatchBB); SwitchInst *CatchSwitch = @@ -577,6 +579,12 @@ bool LowerInvoke::insertExpensiveEHSupport(Function &F) { Unwinds[i]->eraseFromParent(); } + // Replace all inserted unreachables with a branch to the unwind handler. + for (unsigned i = 0, e = Unreachables.size(); i != e; ++i) { + BranchInst::Create(UnwindHandler, Unreachables[i]); + Unreachables[i]->eraseFromParent(); + } + // Finally, for any returns from this function, if this function contains an // invoke, restore the old jmpbuf pointer to its input value. if (OldJmpBufPtr) {