//===- LowerSetJmp.cpp - Code pertaining to lowering set/long jumps -------===//
//
// This file implements the lowering of setjmp and longjmp to use the
-// LLVM invoke instruction as necessary.
+// LLVM invoke and unwind instructions as necessary.
//
// Lowering of longjmp is fairly trivial. We replace the call with a
// call to the LLVM library function "__llvm_sjljeh_throw_longjmp()".
// original except block being executed if it isn't a longjmp except
// that is handled by that function.
//
+// This pass was contributed to LLVM by Bill Wendling.
+//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
{
std::string SJLJEh("__llvm_sjljeh");
- if (Name.size() > SJLJEh.size()) {
- std::string N(Name.begin(), Name.begin() + SJLJEh.size());
- return N != SJLJEh;
- }
+ if (Name.size() > SJLJEh.size())
+ return std::string(Name.begin(), Name.begin() + SJLJEh.size()) != SJLJEh;
return true;
}
SetJmpIDMap[Func]++), 0),
"", Inst);
- // FIXME: This is a nasty piece of code. We want the jump buffer to
- // dominate all uses. However, we're doing unnatural things to the CFG
- // which cause this dominance to be lost. The only way to guarantee we
- // get it back is to place where the jump buffer is being allocated
- // into the entry block. That's what this code does. The alloca for the
- // jump buffer is followed by a getelementptr call.
- if (GetElementPtrInst* GEP = dyn_cast<GetElementPtrInst>(Inst->getOperand(1)))
- if (GEP->use_size() > 1) {
- if (AllocaInst* AI = dyn_cast<AllocaInst>(GEP->getPointerOperand())) {
- BasicBlock& Entry = Func->getEntryNode();
- BasicBlock::InstListType& EntryIL = Entry.getInstList();
-
- Instruction* NewAI = AI->clone();
- Instruction* NewGEP = GEP->clone();
- NewAI->setName(AI->getName());
- NewGEP->setName(GEP->getName());
- EntryIL.push_front(NewGEP);
- EntryIL.push_front(NewAI);
- GEP->replaceAllUsesWith(NewGEP);
- AI->replaceAllUsesWith(NewAI);
- }
- }
-
// Change the setjmp call into a branch statement. We'll remove the
// setjmp call in a little bit. No worries.
BasicBlock* SetJmpContBlock = ABlock->splitBasicBlock(Inst);