-/// FindSelectorAndURoR - Find the eh.selector call associated with the
-/// eh.exception call. And indicate if there is a URoR "invoke" associated with
-/// the eh.exception call. This recursively looks past instructions which don't
-/// change the EH pointer value, like casts or PHI nodes.
-bool
-DwarfEHPrepare::FindSelectorAndURoR(Instruction *Inst, bool &URoRInvoke,
- SmallPtrSet<IntrinsicInst*, 8> &SelCalls,
- SmallPtrSet<PHINode*, 32> &SeenPHIs) {
- bool Changed = false;
-
- for (Value::use_iterator
- I = Inst->use_begin(), E = Inst->use_end(); I != E; ++I) {
- Instruction *II = dyn_cast<Instruction>(*I);
- if (!II || II->getParent()->getParent() != F) continue;
-
- if (IntrinsicInst *Sel = dyn_cast<IntrinsicInst>(II)) {
- if (Sel->getIntrinsicID() == Intrinsic::eh_selector)
- SelCalls.insert(Sel);
- } else if (InvokeInst *Invoke = dyn_cast<InvokeInst>(II)) {
- if (Invoke->getCalledFunction() == URoR)
- URoRInvoke = true;
- } else if (CastInst *CI = dyn_cast<CastInst>(II)) {
- Changed |= FindSelectorAndURoR(CI, URoRInvoke, SelCalls, SeenPHIs);
- } else if (PHINode *PN = dyn_cast<PHINode>(II)) {
- if (SeenPHIs.insert(PN))
- // Don't process a PHI node more than once.
- Changed |= FindSelectorAndURoR(PN, URoRInvoke, SelCalls, SeenPHIs);
- }
- }
-
- return Changed;
-}
-
-/// HandleURoRInvokes - Handle invokes of "_Unwind_Resume_or_Rethrow" or
-/// "_Unwind_SjLj_Resume" calls. The "unwind" part of these invokes jump to a
-/// landing pad within the current function. This is a candidate to merge the
-/// selector associated with the URoR invoke with the one from the URoR's
-/// landing pad.
-bool DwarfEHPrepare::HandleURoRInvokes() {
- if (!EHCatchAllValue) {
- EHCatchAllValue =
- F->getParent()->getNamedGlobal("llvm.eh.catch.all.value");
- if (!EHCatchAllValue) return false;
- }
-
- if (!SelectorIntrinsic) {
- SelectorIntrinsic =
- Intrinsic::getDeclaration(F->getParent(), Intrinsic::eh_selector);
- if (!SelectorIntrinsic) return false;
- }
-
- SmallPtrSet<IntrinsicInst*, 32> Sels;
- SmallPtrSet<IntrinsicInst*, 32> CatchAllSels;
- FindAllCleanupSelectors(Sels, CatchAllSels);
-
- if (!URoR) {
- URoR = F->getParent()->getFunction("_Unwind_Resume_or_Rethrow");
- if (!URoR) return CleanupSelectors(CatchAllSels);
- }
-
- SmallPtrSet<InvokeInst*, 32> URoRInvokes;
- FindAllURoRInvokes(URoRInvokes);
-
- SmallPtrSet<IntrinsicInst*, 32> SelsToConvert;
-
- for (SmallPtrSet<IntrinsicInst*, 32>::iterator
- SI = Sels.begin(), SE = Sels.end(); SI != SE; ++SI) {
- const BasicBlock *SelBB = (*SI)->getParent();
- for (SmallPtrSet<InvokeInst*, 32>::iterator
- UI = URoRInvokes.begin(), UE = URoRInvokes.end(); UI != UE; ++UI) {
- const BasicBlock *URoRBB = (*UI)->getParent();
- if (DT->dominates(SelBB, URoRBB)) {
- SelsToConvert.insert(*SI);
- break;
- }
- }
- }
-
- bool Changed = false;
-
- if (Sels.size() != SelsToConvert.size()) {
- // If we haven't been able to convert all of the clean-up selectors, then
- // loop through the slow way to see if they still need to be converted.
- if (!ExceptionValueIntrinsic) {
- ExceptionValueIntrinsic =
- Intrinsic::getDeclaration(F->getParent(), Intrinsic::eh_exception);
- if (!ExceptionValueIntrinsic)
- return CleanupSelectors(CatchAllSels);
- }
-
- for (Value::use_iterator
- I = ExceptionValueIntrinsic->use_begin(),
- E = ExceptionValueIntrinsic->use_end(); I != E; ++I) {
- IntrinsicInst *EHPtr = dyn_cast<IntrinsicInst>(*I);
- if (!EHPtr || EHPtr->getParent()->getParent() != F) continue;
-
- bool URoRInvoke = false;
- SmallPtrSet<IntrinsicInst*, 8> SelCalls;
- SmallPtrSet<PHINode*, 32> SeenPHIs;
- Changed |= FindSelectorAndURoR(EHPtr, URoRInvoke, SelCalls, SeenPHIs);
-
- if (URoRInvoke) {
- // This EH pointer is being used by an invoke of an URoR instruction and
- // an eh.selector intrinsic call. If the eh.selector is a 'clean-up', we
- // need to convert it to a 'catch-all'.
- for (SmallPtrSet<IntrinsicInst*, 8>::iterator
- SI = SelCalls.begin(), SE = SelCalls.end(); SI != SE; ++SI)
- if (!HasCatchAllInSelector(*SI))
- SelsToConvert.insert(*SI);
- }
- }
- }
-
- if (!SelsToConvert.empty()) {
- // Convert all clean-up eh.selectors, which are associated with "invokes" of
- // URoR calls, into catch-all eh.selectors.
- Changed = true;
-
- for (SmallPtrSet<IntrinsicInst*, 8>::iterator
- SI = SelsToConvert.begin(), SE = SelsToConvert.end();
- SI != SE; ++SI) {
- IntrinsicInst *II = *SI;
-
- // Use the exception object pointer and the personality function
- // from the original selector.
- CallSite CS(II);
- IntrinsicInst::op_iterator I = CS.arg_begin();
- IntrinsicInst::op_iterator E = CS.arg_end();
- IntrinsicInst::op_iterator B = prior(E);
-
- // Exclude last argument if it is an integer.
- if (isa<ConstantInt>(B)) E = B;
-
- // Add exception object pointer (front).
- // Add personality function (next).
- // Add in any filter IDs (rest).
- SmallVector<Value*, 8> Args(I, E);
-
- Args.push_back(EHCatchAllValue->getInitializer()); // Catch-all indicator.
-
- CallInst *NewSelector =
- CallInst::Create(SelectorIntrinsic, Args, "eh.sel.catch.all", II);
-
- NewSelector->setTailCall(II->isTailCall());
- NewSelector->setAttributes(II->getAttributes());
- NewSelector->setCallingConv(II->getCallingConv());
-
- II->replaceAllUsesWith(NewSelector);
- II->eraseFromParent();
- }
- }
-
- Changed |= CleanupSelectors(CatchAllSels);
- return Changed;
-}
-
-/// NormalizeLandingPads - Normalize and discover landing pads, noting them
-/// in the LandingPads set. A landing pad is normal if the only CFG edges
-/// that end at it are unwind edges from invoke instructions. If we inlined
-/// through an invoke we could have a normal branch from the previous
-/// unwind block through to the landing pad for the original invoke.
-/// Abnormal landing pads are fixed up by redirecting all unwind edges to
-/// a new basic block which falls through to the original.
-bool DwarfEHPrepare::NormalizeLandingPads() {
- bool Changed = false;
-
- const MCAsmInfo *MAI = TM->getMCAsmInfo();
- bool usingSjLjEH = MAI->getExceptionHandlingType() == ExceptionHandling::SjLj;
-
- for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
- TerminatorInst *TI = I->getTerminator();
- if (!isa<InvokeInst>(TI))
- continue;
- BasicBlock *LPad = TI->getSuccessor(1);
- // Skip landing pads that have already been normalized.
- if (LandingPads.count(LPad))
- continue;
-
- // Check that only invoke unwind edges end at the landing pad.
- bool OnlyUnwoundTo = true;
- bool SwitchOK = usingSjLjEH;
- for (pred_iterator PI = pred_begin(LPad), PE = pred_end(LPad);
- PI != PE; ++PI) {
- TerminatorInst *PT = (*PI)->getTerminator();
- // The SjLj dispatch block uses a switch instruction. This is effectively
- // an unwind edge, so we can disregard it here. There will only ever
- // be one dispatch, however, so if there are multiple switches, one
- // of them truly is a normal edge, not an unwind edge.
- if (SwitchOK && isa<SwitchInst>(PT)) {
- SwitchOK = false;
- continue;