void mapLandingPadBlocks(LandingPadInst *LPad, LandingPadActions &Actions);
CatchHandler *findCatchHandler(BasicBlock *BB, BasicBlock *&NextBB,
VisitedBlockSet &VisitedBlocks);
- CleanupHandler *findCleanupHandler(BasicBlock *StartBB, BasicBlock *EndBB);
+ void findCleanupHandlers(LandingPadActions &Actions, BasicBlock *StartBB,
+ BasicBlock *EndBB);
void processSEHCatchHandler(CatchHandler *Handler, BasicBlock *StartBB);
LandingPadActions Actions;
mapLandingPadBlocks(LPad, Actions);
+ HandlersOutlined |= !Actions.actions().empty();
for (ActionHandler *Action : Actions) {
if (Action->hasBeenProcessed())
continue;
if (isAsynchronousEHPersonality(Personality)) {
if (auto *CatchAction = dyn_cast<CatchHandler>(Action)) {
processSEHCatchHandler(CatchAction, StartBB);
- HandlersOutlined = true;
continue;
}
}
- if (outlineHandler(Action, &F, LPad, StartBB, FrameVarInfo)) {
- HandlersOutlined = true;
- }
- } // End for each Action
-
- // FIXME: We need a guard against partially outlined functions.
- if (!HandlersOutlined)
- continue;
+ outlineHandler(Action, &F, LPad, StartBB, FrameVarInfo);
+ }
// Replace the landing pad with a new llvm.eh.action based landing pad.
BasicBlock *NewLPadBB = BasicBlock::Create(Context, "lpad", &F, LPadBB);
DEBUG(dbgs() << "Mapping landing pad: " << BB->getName() << "\n");
if (NumClauses == 0) {
- // This landing pad contains only cleanup code.
- CleanupHandler *Action = new CleanupHandler(BB);
- CleanupHandlerMap[BB] = Action;
- Actions.insertCleanupHandler(Action);
- DEBUG(dbgs() << " Assuming cleanup code in block " << BB->getName()
- << "\n");
- assert(LPad->isCleanup());
+ findCleanupHandlers(Actions, BB, nullptr);
return;
}
// exceptions but code called from catches can. For SEH, it isn't
// important if some finally code before a catch-all is executed out of
// line or after recovering from the exception.
- if (Personality == EHPersonality::MSVC_CXX) {
- if (auto *CleanupAction = findCleanupHandler(BB, BB)) {
- // Add a cleanup entry to the list
- Actions.insertCleanupHandler(CleanupAction);
- DEBUG(dbgs() << " Found cleanup code in block "
- << CleanupAction->getStartBlock()->getName() << "\n");
- }
- }
+ if (Personality == EHPersonality::MSVC_CXX)
+ findCleanupHandlers(Actions, BB, BB);
// Add the catch handler to the action list.
CatchHandler *Action =
CatchHandler *CatchAction = findCatchHandler(BB, NextBB, VisitedBlocks);
// See if there is any interesting code executed before the dispatch.
- if (auto *CleanupAction =
- findCleanupHandler(BB, CatchAction->getStartBlock())) {
- // Add a cleanup entry to the list
- Actions.insertCleanupHandler(CleanupAction);
- DEBUG(dbgs() << " Found cleanup code in block "
- << CleanupAction->getStartBlock()->getName() << "\n");
- }
+ findCleanupHandlers(Actions, BB, CatchAction->getStartBlock());
assert(CatchAction);
++HandlersFound;
// If we didn't wind up in a catch-all, see if there is any interesting code
// executed before the resume.
- if (auto *CleanupAction = findCleanupHandler(BB, BB)) {
- // Add a cleanup entry to the list
- Actions.insertCleanupHandler(CleanupAction);
- DEBUG(dbgs() << " Found cleanup code in block "
- << CleanupAction->getStartBlock()->getName() << "\n");
- }
+ findCleanupHandlers(Actions, BB, BB);
// It's possible that some optimization moved code into a landingpad that
// wasn't
return nullptr;
}
-// These are helper functions to combine repeated code from findCleanupHandler.
-static CleanupHandler *
-createCleanupHandler(CleanupHandlerMapTy &CleanupHandlerMap, BasicBlock *BB) {
+// These are helper functions to combine repeated code from findCleanupHandlers.
+static void createCleanupHandler(LandingPadActions &Actions,
+ CleanupHandlerMapTy &CleanupHandlerMap,
+ BasicBlock *BB) {
CleanupHandler *Action = new CleanupHandler(BB);
CleanupHandlerMap[BB] = Action;
- return Action;
+ Actions.insertCleanupHandler(Action);
+ DEBUG(dbgs() << " Found cleanup code in block "
+ << Action->getStartBlock()->getName() << "\n");
+}
+
+static bool isFrameAddressCall(Value *V) {
+ return match(V, m_Intrinsic<Intrinsic::frameaddress>(m_SpecificInt(0)));
+}
+
+static CallSite matchOutlinedFinallyCall(BasicBlock *BB,
+ Instruction *MaybeCall) {
+ // Look for finally blocks that Clang has already outlined for us.
+ // %fp = call i8* @llvm.frameaddress(i32 0)
+ // call void @"fin$parent"(iN 1, i8* %fp)
+ if (isFrameAddressCall(MaybeCall) && MaybeCall != BB->getTerminator())
+ MaybeCall = MaybeCall->getNextNode();
+ CallSite FinallyCall(MaybeCall);
+ if (!FinallyCall || FinallyCall.arg_size() != 2)
+ return CallSite();
+ if (!match(FinallyCall.getArgument(0), m_SpecificInt(1)))
+ return CallSite();
+ if (!isFrameAddressCall(FinallyCall.getArgument(1)))
+ return CallSite();
+ return FinallyCall;
+}
+
+static BasicBlock *followSingleUnconditionalBranches(BasicBlock *BB) {
+ // Skip single ubr blocks.
+ while (BB->getFirstNonPHIOrDbg() == BB->getTerminator()) {
+ auto *Br = dyn_cast<BranchInst>(BB->getTerminator());
+ if (Br && Br->isUnconditional())
+ BB = Br->getSuccessor(0);
+ else
+ return BB;
+ }
+ return BB;
}
// This function searches starting with the input block for the next block that
// contains code that is not part of a catch handler and would not be eliminated
// during handler outlining.
//
-CleanupHandler *WinEHPrepare::findCleanupHandler(BasicBlock *StartBB,
- BasicBlock *EndBB) {
+void WinEHPrepare::findCleanupHandlers(LandingPadActions &Actions,
+ BasicBlock *StartBB, BasicBlock *EndBB) {
// Here we will skip over the following:
//
// landing pad prolog:
// Anything other than an unconditional branch will kick us out of this loop
// one way or another.
while (BB) {
+ BB = followSingleUnconditionalBranches(BB);
// If we've already scanned this block, don't scan it again. If it is
// a cleanup block, there will be an action in the CleanupHandlerMap.
// If we've scanned it and it is not a cleanup block, there will be a
// avoid creating a null entry for blocks we haven't scanned.
if (CleanupHandlerMap.count(BB)) {
if (auto *Action = CleanupHandlerMap[BB]) {
- return cast<CleanupHandler>(Action);
+ Actions.insertCleanupHandler(Action);
+ DEBUG(dbgs() << " Found cleanup code in block "
+ << Action->getStartBlock()->getName() << "\n");
+ // FIXME: This cleanup might chain into another, and we need to discover
+ // that.
+ return;
} else {
// Here we handle the case where the cleanup handler map contains a
// value for this block but the value is a nullptr. This means that
// would terminate the search for cleanup code, so the unconditional
// branch is the only case for which we might need to continue
// searching.
- if (BB == EndBB)
- return nullptr;
- BasicBlock *SuccBB;
- if (!match(BB->getTerminator(), m_UnconditionalBr(SuccBB)))
- return nullptr;
+ BasicBlock *SuccBB = followSingleUnconditionalBranches(BB);
+ if (SuccBB == BB || SuccBB == EndBB)
+ return;
BB = SuccBB;
continue;
}
// If there is only one landingpad, we may use the lpad directly with no
// insertions.
if (isa<LandingPadInst>(ResumeVal))
- return nullptr;
+ return;
if (!isa<PHINode>(ResumeVal)) {
Insert2 = dyn_cast<InsertValueInst>(ResumeVal);
if (!Insert2)
- return createCleanupHandler(CleanupHandlerMap, BB);
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
Insert1 = dyn_cast<InsertValueInst>(Insert2->getAggregateOperand());
if (!Insert1)
- return createCleanupHandler(CleanupHandlerMap, BB);
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
}
for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
II != IE; ++II) {
continue;
if (!Inst->hasOneUse() ||
(Inst->user_back() != Insert1 && Inst->user_back() != Insert2)) {
- return createCleanupHandler(CleanupHandlerMap, BB);
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
}
}
- return nullptr;
+ return;
}
BranchInst *Branch = dyn_cast<BranchInst>(Terminator);
// br i1 %matches, label %catch14, label %eh.resume
CmpInst *Compare = dyn_cast<CmpInst>(Branch->getCondition());
if (!Compare || !Compare->isEquality())
- return createCleanupHandler(CleanupHandlerMap, BB);
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
II != IE; ++II) {
Instruction *Inst = II;
continue;
if (match(Inst, m_Intrinsic<Intrinsic::eh_typeid_for>()))
continue;
- return createCleanupHandler(CleanupHandlerMap, BB);
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
}
// The selector dispatch block should always terminate our search.
assert(BB == EndBB);
- return nullptr;
+ return;
+ }
+
+ if (isAsynchronousEHPersonality(Personality)) {
+ // If this is a landingpad block, split the block at the first non-landing
+ // pad instruction.
+ Instruction *MaybeCall = BB->getFirstNonPHIOrDbg();
+ if (LPadMap) {
+ while (MaybeCall != BB->getTerminator() &&
+ LPadMap->isLandingPadSpecificInst(MaybeCall))
+ MaybeCall = MaybeCall->getNextNode();
+ }
+
+ // Look for outlined finally calls.
+ if (CallSite FinallyCall = matchOutlinedFinallyCall(BB, MaybeCall)) {
+ Function *Fin = FinallyCall.getCalledFunction();
+ assert(Fin && "outlined finally call should be direct");
+ auto *Action = new CleanupHandler(BB);
+ Action->setHandlerBlockOrFunc(Fin);
+ Actions.insertCleanupHandler(Action);
+ CleanupHandlerMap[BB] = Action;
+ DEBUG(dbgs() << " Found frontend-outlined finally call to "
+ << Fin->getName() << " in block "
+ << Action->getStartBlock()->getName() << "\n");
+
+ // Split the block if there were more interesting instructions and look
+ // for finally calls in the normal successor block.
+ BasicBlock *SuccBB = BB;
+ if (FinallyCall.getInstruction() != BB->getTerminator() &&
+ FinallyCall.getInstruction()->getNextNode() != BB->getTerminator()) {
+ SuccBB = BB->splitBasicBlock(FinallyCall.getInstruction()->getNextNode());
+ } else {
+ if (FinallyCall.isInvoke()) {
+ SuccBB = cast<InvokeInst>(FinallyCall.getInstruction())->getNormalDest();
+ } else {
+ SuccBB = BB->getUniqueSuccessor();
+ assert(SuccBB && "splitOutlinedFinallyCalls didn't insert a branch");
+ }
+ }
+ BB = SuccBB;
+ if (BB == EndBB)
+ return;
+ continue;
+ }
}
// Anything else is either a catch block or interesting cleanup code.
continue;
// If this is a catch block, there is no cleanup code to be found.
if (match(Inst, m_Intrinsic<Intrinsic::eh_begincatch>()))
- return nullptr;
+ return;
// If this a nested landing pad, it may contain an endcatch call.
if (match(Inst, m_Intrinsic<Intrinsic::eh_endcatch>()))
- return nullptr;
+ return;
// Anything else makes this interesting cleanup code.
- return createCleanupHandler(CleanupHandlerMap, BB);
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
}
// Only unconditional branches in empty blocks should get this far.
assert(Branch && Branch->isUnconditional());
if (BB == EndBB)
- return nullptr;
+ return;
BB = Branch->getSuccessor(0);
}
- return nullptr;
+ return;
}
// This is a public function, declared in WinEHFuncInfo.h and is also
--- /dev/null
+; RUN: opt -S -winehprepare -sehprepare -mtriple=x86_64-windows-msvc < %s | FileCheck %s
+
+; Test case based on this code:
+;
+; extern "C" int _abnormal_termination();
+; #pragma intrinsic(_abnormal_termination)
+; extern "C" int printf(const char *, ...);
+; extern "C" void may_crash() {
+; *(volatile int *)0 = 42;
+; }
+; int main() {
+; int myres = 0;
+; __try {
+; __try {
+; may_crash();
+; } __finally {
+; printf("inner finally %d\n", _abnormal_termination());
+; may_crash();
+; }
+; } __finally {
+; printf("outer finally %d\n", _abnormal_termination());
+; }
+; }
+;
+; Note that if the inner finally crashes, the outer finally still runs. There
+; is nothing like a std::terminate call in this situation.
+
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc"
+
+@str_outer_finally = linkonce_odr unnamed_addr constant [18 x i8] c"outer finally %d\0A\00", align 1
+@str_inner_finally = linkonce_odr unnamed_addr constant [18 x i8] c"inner finally %d\0A\00", align 1
+
+; Function Attrs: nounwind uwtable
+define void @may_crash() #0 {
+entry:
+ store volatile i32 42, i32* null, align 4
+ ret void
+}
+
+; Function Attrs: uwtable
+define i32 @main() #1 {
+entry:
+ %myres = alloca i32, align 4
+ %exn.slot = alloca i8*
+ %ehselector.slot = alloca i32
+ store i32 0, i32* %myres, align 4
+ invoke void @may_crash() #4
+ to label %invoke.cont unwind label %lpad
+
+invoke.cont: ; preds = %entry
+ %0 = call i8* @llvm.frameaddress(i32 0)
+ invoke void @"\01?fin$1@0@main@@"(i1 zeroext false, i8* %0) #4
+ to label %invoke.cont2 unwind label %lpad1
+
+invoke.cont2: ; preds = %invoke.cont
+ %1 = call i8* @llvm.frameaddress(i32 0)
+ call void @"\01?fin$0@0@main@@"(i1 zeroext false, i8* %1)
+ ret i32 0
+
+lpad: ; preds = %entry
+ %2 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*)
+ cleanup
+ %3 = extractvalue { i8*, i32 } %2, 0
+ store i8* %3, i8** %exn.slot
+ %4 = extractvalue { i8*, i32 } %2, 1
+ store i32 %4, i32* %ehselector.slot
+ %5 = call i8* @llvm.frameaddress(i32 0)
+ invoke void @"\01?fin$1@0@main@@"(i1 zeroext true, i8* %5) #4
+ to label %invoke.cont3 unwind label %lpad1
+
+lpad1: ; preds = %lpad, %invoke.cont
+ %6 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*)
+ cleanup
+ %7 = extractvalue { i8*, i32 } %6, 0
+ store i8* %7, i8** %exn.slot
+ %8 = extractvalue { i8*, i32 } %6, 1
+ store i32 %8, i32* %ehselector.slot
+ br label %ehcleanup
+
+invoke.cont3: ; preds = %lpad
+ br label %ehcleanup
+
+ehcleanup: ; preds = %invoke.cont3, %lpad1
+ %9 = call i8* @llvm.frameaddress(i32 0)
+ call void @"\01?fin$0@0@main@@"(i1 zeroext true, i8* %9)
+ br label %eh.resume
+
+eh.resume: ; preds = %ehcleanup
+ %exn = load i8*, i8** %exn.slot
+ %sel = load i32, i32* %ehselector.slot
+ %lpad.val = insertvalue { i8*, i32 } undef, i8* %exn, 0
+ %lpad.val4 = insertvalue { i8*, i32 } %lpad.val, i32 %sel, 1
+ resume { i8*, i32 } %lpad.val4
+}
+
+; CHECK-NOT: define internal void @
+
+; CHECK-LABEL: define i32 @main()
+; CHECK: invoke void @may_crash()
+;
+; CHECK: landingpad { i8*, i32 }
+; CHECK-NEXT: cleanup
+; CHECK-NEXT: call i8* (...)* @llvm.eh.actions(i32 0, void (i1, i8*)* @"\01?fin$1@0@main@@", i32 0, void (i1, i8*)* @"\01?fin$0@0@main@@")
+; CHECK-NEXT: indirectbr
+;
+; CHECK: landingpad { i8*, i32 }
+; CHECK-NEXT: cleanup
+; CHECK-NEXT: call i8* (...)* @llvm.eh.actions(i32 0, void (i1, i8*)* @"\01?fin$0@0@main@@")
+; CHECK-NEXT: indirectbr
+
+; There should not be any *new* cleanup helpers, just the existing ones.
+; CHECK-NOT: define internal void @
+; CHECK: define internal void @"\01?fin$0@0@main@@"(i1 zeroext %abnormal_termination, i8* %frame_pointer)
+; CHECK-NOT: define internal void @
+; CHECK: define internal void @"\01?fin$1@0@main@@"(i1 zeroext %abnormal_termination, i8* %frame_pointer)
+; CHECK-NOT: define internal void @
+
+define internal void @"\01?fin$0@0@main@@"(i1 zeroext %abnormal_termination, i8* %frame_pointer) #2 {
+entry:
+ %frame_pointer.addr = alloca i8*, align 8
+ %abnormal_termination.addr = alloca i8, align 1
+ store i8* %frame_pointer, i8** %frame_pointer.addr, align 8
+ %frombool = zext i1 %abnormal_termination to i8
+ store i8 %frombool, i8* %abnormal_termination.addr, align 1
+ %0 = zext i1 %abnormal_termination to i32
+ %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @str_outer_finally, i32 0, i32 0), i32 %0)
+ ret void
+}
+
+declare i32 @printf(i8*, ...) #2
+
+define internal void @"\01?fin$1@0@main@@"(i1 zeroext %abnormal_termination, i8* %frame_pointer) #2 {
+entry:
+ %frame_pointer.addr = alloca i8*, align 8
+ %abnormal_termination.addr = alloca i8, align 1
+ store i8* %frame_pointer, i8** %frame_pointer.addr, align 8
+ %frombool = zext i1 %abnormal_termination to i8
+ store i8 %frombool, i8* %abnormal_termination.addr, align 1
+ %0 = zext i1 %abnormal_termination to i32
+ %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @str_inner_finally, i32 0, i32 0), i32 %0)
+ call void @may_crash()
+ ret void
+}
+
+declare i32 @__C_specific_handler(...)
+
+; Function Attrs: nounwind readnone
+declare i8* @llvm.frameaddress(i32) #3
+
+attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #3 = { nounwind readnone }
+attributes #4 = { noinline }