void visitCatchPadInst(CatchPadInst &CPI);
void visitCatchReturnInst(CatchReturnInst &CatchReturn);
void visitCleanupPadInst(CleanupPadInst &CPI);
+ void visitFuncletPadInst(FuncletPadInst &FPI);
void visitCatchSwitchInst(CatchSwitchInst &CatchSwitch);
void visitCleanupReturnInst(CleanupReturnInst &CRI);
Assert(BB->getFirstNonPHI() == &CPI,
"CatchPadInst not the first non-PHI instruction in the block.", &CPI);
- visitInstruction(CPI);
+ visitFuncletPadInst(CPI);
}
void Verifier::visitCatchReturnInst(CatchReturnInst &CatchReturn) {
Assert(isa<ConstantTokenNone>(ParentPad) || isa<FuncletPadInst>(ParentPad),
"CleanupPadInst has an invalid parent.", &CPI);
+ visitFuncletPadInst(CPI);
+}
+
+void Verifier::visitFuncletPadInst(FuncletPadInst &FPI) {
User *FirstUser = nullptr;
- BasicBlock *FirstUnwindDest = nullptr;
- for (User *U : CPI.users()) {
- BasicBlock *UnwindDest;
- if (CleanupReturnInst *CRI = dyn_cast<CleanupReturnInst>(U)) {
- UnwindDest = CRI->getUnwindDest();
- } else if (isa<CleanupPadInst>(U) || isa<CatchSwitchInst>(U)) {
- continue;
- } else if (CallSite(U)) {
- continue;
- } else {
- Assert(false, "bogus cleanuppad use", &CPI);
+ Value *FirstUnwindPad = nullptr;
+ SmallVector<FuncletPadInst *, 8> Worklist({&FPI});
+ while (!Worklist.empty()) {
+ FuncletPadInst *CurrentPad = Worklist.pop_back_val();
+ Value *UnresolvedAncestorPad = nullptr;
+ for (User *U : CurrentPad->users()) {
+ BasicBlock *UnwindDest;
+ if (auto *CRI = dyn_cast<CleanupReturnInst>(U)) {
+ UnwindDest = CRI->getUnwindDest();
+ } else if (auto *CSI = dyn_cast<CatchSwitchInst>(U)) {
+ // We allow catchswitch unwind to caller to nest
+ // within an outer pad that unwinds somewhere else,
+ // because catchswitch doesn't have a nounwind variant.
+ // See e.g. SimplifyCFGOpt::SimplifyUnreachable.
+ if (CSI->unwindsToCaller())
+ continue;
+ UnwindDest = CSI->getUnwindDest();
+ } else if (auto *II = dyn_cast<InvokeInst>(U)) {
+ UnwindDest = II->getUnwindDest();
+ } else if (isa<CallInst>(U)) {
+ // Calls which don't unwind may be found inside funclet
+ // pads that unwind somewhere else. We don't *require*
+ // such calls to be annotated nounwind.
+ continue;
+ } else if (auto *CPI = dyn_cast<CleanupPadInst>(U)) {
+ // The unwind dest for a cleanup can only be found by
+ // recursive search. Add it to the worklist, and we'll
+ // search for its first use that determines where it unwinds.
+ Worklist.push_back(CPI);
+ continue;
+ } else {
+ Assert(isa<CatchReturnInst>(U), "Bogus funclet pad use", U);
+ continue;
+ }
+
+ Value *UnwindPad;
+ bool ExitsFPI;
+ if (UnwindDest) {
+ UnwindPad = UnwindDest->getFirstNonPHI();
+ Value *UnwindParent = getParentPad(UnwindPad);
+ // Ignore unwind edges that don't exit CurrentPad.
+ if (UnwindParent == CurrentPad)
+ continue;
+ // Determine whether the original funclet pad is exited,
+ // and if we are scanning nested pads determine how many
+ // of them are exited so we can stop searching their
+ // children.
+ Value *ExitedPad = CurrentPad;
+ ExitsFPI = false;
+ do {
+ if (ExitedPad == &FPI) {
+ ExitsFPI = true;
+ // Now we can resolve any ancestors of CurrentPad up to
+ // FPI, but not including FPI since we need to make sure
+ // to check all direct users of FPI for consistency.
+ UnresolvedAncestorPad = &FPI;
+ break;
+ }
+ Value *ExitedParent = getParentPad(ExitedPad);
+ if (ExitedParent == UnwindParent) {
+ // ExitedPad is the ancestor-most pad which this unwind
+ // edge exits, so we can resolve up to it, meaning that
+ // ExitedParent is the first ancestor still unresolved.
+ UnresolvedAncestorPad = ExitedParent;
+ break;
+ }
+ ExitedPad = ExitedParent;
+ } while (!isa<ConstantTokenNone>(ExitedPad));
+ } else {
+ // Unwinding to caller exits all pads.
+ UnwindPad = ConstantTokenNone::get(FPI.getContext());
+ ExitsFPI = true;
+ UnresolvedAncestorPad = &FPI;
+ }
+
+ if (ExitsFPI) {
+ // This unwind edge exits FPI. Make sure it agrees with other
+ // such edges.
+ if (FirstUser) {
+ Assert(UnwindPad == FirstUnwindPad, "Unwind edges out of a funclet "
+ "pad must have the same unwind "
+ "dest",
+ &FPI, U, FirstUser);
+ } else {
+ FirstUser = U;
+ FirstUnwindPad = UnwindPad;
+ }
+ }
+ // Make sure we visit all uses of FPI, but for nested pads stop as
+ // soon as we know where they unwind to.
+ if (CurrentPad != &FPI)
+ break;
}
+ if (UnresolvedAncestorPad) {
+ if (CurrentPad == UnresolvedAncestorPad) {
+ // When CurrentPad is FPI itself, we don't mark it as resolved even if
+ // we've found an unwind edge that exits it, because we need to verify
+ // all direct uses of FPI.
+ assert(CurrentPad == &FPI);
+ continue;
+ }
+ // Pop off the worklist any nested pads that we've found an unwind
+ // destination for. The pads on the worklist are the uncles,
+ // great-uncles, etc. of CurrentPad. We've found an unwind destination
+ // for all ancestors of CurrentPad up to but not including
+ // UnresolvedAncestorPad.
+ Value *ResolvedPad = CurrentPad;
+ while (!Worklist.empty()) {
+ Value *UnclePad = Worklist.back();
+ Value *AncestorPad = getParentPad(UnclePad);
+ // Walk ResolvedPad up the ancestor list until we either find the
+ // uncle's parent or the last resolved ancestor.
+ while (ResolvedPad != AncestorPad) {
+ Value *ResolvedParent = getParentPad(ResolvedPad);
+ if (ResolvedParent == UnresolvedAncestorPad) {
+ break;
+ }
+ ResolvedPad = ResolvedParent;
+ }
+ // If the resolved ancestor search didn't find the uncle's parent,
+ // then the uncle is not yet resolved.
+ if (ResolvedPad != AncestorPad)
+ break;
+ // This uncle is resolved, so pop it from the worklist.
+ Worklist.pop_back();
+ }
+ }
+ }
- if (!FirstUser) {
- FirstUser = U;
- FirstUnwindDest = UnwindDest;
- } else {
- Assert(
- UnwindDest == FirstUnwindDest,
- "cleanupret instructions from the same cleanuppad must have the same "
- "unwind destination",
- FirstUser, U);
+ if (FirstUnwindPad) {
+ if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(FPI.getParentPad())) {
+ BasicBlock *SwitchUnwindDest = CatchSwitch->getUnwindDest();
+ Value *SwitchUnwindPad;
+ if (SwitchUnwindDest)
+ SwitchUnwindPad = SwitchUnwindDest->getFirstNonPHI();
+ else
+ SwitchUnwindPad = ConstantTokenNone::get(FPI.getContext());
+ Assert(SwitchUnwindPad == FirstUnwindPad,
+ "Unwind edges out of a catch must have the same unwind dest as "
+ "the parent catchswitch",
+ &FPI, FirstUser, CatchSwitch);
}
}
- visitInstruction(CPI);
+ visitInstruction(FPI);
}
void Verifier::visitCatchSwitchInst(CatchSwitchInst &CatchSwitch) {