void promoteLandingPadValues(LandingPadInst *LPad);
void demoteValuesLiveAcrossHandlers(Function &F,
SmallVectorImpl<LandingPadInst *> &LPads);
+ void findSEHEHReturnPoints(Function &F,
+ SetVector<BasicBlock *> &EHReturnBlocks);
+ void findCXXEHReturnPoints(Function &F,
+ SetVector<BasicBlock *> &EHReturnBlocks);
void completeNestedLandingPad(Function *ParentFn,
LandingPadInst *OutlinedLPad,
const LandingPadInst *OriginalLPad,
}
}
+// Attempt to find an instruction where a block can be split before
+// a call to llvm.eh.begincatch and its operands. If the block
+// begins with the begincatch call or one of its adjacent operands
+// the block will not be split.
+static Instruction *findBeginCatchSplitPoint(BasicBlock *BB,
+ IntrinsicInst *II) {
+ // If the begincatch call is already the first instruction in the block,
+ // don't split.
+ Instruction *FirstNonPHI = BB->getFirstNonPHI();
+ if (II == FirstNonPHI)
+ return nullptr;
+
+ // If either operand is in the same basic block as the instruction and
+ // isn't used by another instruction before the begincatch call, include it
+ // in the split block.
+ auto *Op0 = dyn_cast<Instruction>(II->getOperand(0));
+ auto *Op1 = dyn_cast<Instruction>(II->getOperand(1));
+
+ Instruction *I = II->getPrevNode();
+ Instruction *LastI = II;
+
+ while (I == Op0 || I == Op1) {
+ // If the block begins with one of the operands and there are no other
+ // instructions between the operand and the begincatch call, don't split.
+ if (I == FirstNonPHI)
+ return nullptr;
+
+ LastI = I;
+ I = I->getPrevNode();
+ }
+
+ // If there is at least one instruction in the block before the begincatch
+ // call and its operands, split the block at either the begincatch or
+ // its operand.
+ return LastI;
+}
+
/// Find all points where exceptional control rejoins normal control flow via
/// llvm.eh.endcatch. Add them to the normal bb reachability worklist.
-static void findCXXEHReturnPoints(Function &F,
- SetVector<BasicBlock *> &EHReturnBlocks) {
+void WinEHPrepare::findCXXEHReturnPoints(
+ Function &F, SetVector<BasicBlock *> &EHReturnBlocks) {
for (auto BBI = F.begin(), BBE = F.end(); BBI != BBE; ++BBI) {
BasicBlock *BB = BBI;
for (Instruction &I : *BB) {
+ if (match(&I, m_Intrinsic<Intrinsic::eh_begincatch>())) {
+ Instruction *SplitPt =
+ findBeginCatchSplitPoint(BB, cast<IntrinsicInst>(&I));
+ if (SplitPt) {
+ // Split the block before the llvm.eh.begincatch call to allow
+ // cleanup and catch code to be distinguished later.
+ // Do not update BBI because we still need to process the
+ // portion of the block that we are splitting off.
+ SplitBlock(BB, &I, DT);
+ break;
+ }
+ }
if (match(&I, m_Intrinsic<Intrinsic::eh_endcatch>())) {
// Split the block after the call to llvm.eh.endcatch if there is
// anything other than an unconditional branch, or if the successor
isa<PHINode>(Br->getSuccessor(0)->begin())) {
DEBUG(dbgs() << "splitting block " << BB->getName()
<< " with llvm.eh.endcatch\n");
- BBI = BB->splitBasicBlock(I.getNextNode(), "ehreturn");
+ BBI = SplitBlock(BB, I.getNextNode(), DT);
}
// The next BB is normal control flow.
EHReturnBlocks.insert(BB->getTerminator()->getSuccessor(0));
/// Find all points where exceptions control rejoins normal control flow via
/// selector dispatch.
-static void findSEHEHReturnPoints(Function &F,
- SetVector<BasicBlock *> &EHReturnBlocks) {
+void WinEHPrepare::findSEHEHReturnPoints(
+ Function &F, SetVector<BasicBlock *> &EHReturnBlocks) {
for (auto BBI = F.begin(), BBE = F.end(); BBI != BBE; ++BBI) {
BasicBlock *BB = BBI;
// If the landingpad is a catch-all, treat the whole lpad as if it is
// Split the block after the landingpad instruction so that it is just a
// call to llvm.eh.actions followed by indirectbr.
assert(!isa<PHINode>(LPadBB->begin()) && "lpad phi not removed");
- LPadBB->splitBasicBlock(LPad->getNextNode(),
- LPadBB->getName() + ".prepsplit");
+ SplitBlock(LPadBB, LPad->getNextNode(), DT);
// Erase the branch inserted by the split so we can insert indirectbr.
LPadBB->getTerminator()->eraseFromParent();
else
Term = Unreached;
BasicBlock *OldRetBB = Term->getParent();
- BasicBlock *NewRetBB = SplitBlock(OldRetBB, Term);
+ BasicBlock *NewRetBB = SplitBlock(OldRetBB, Term, DT);
// SplitBlock adds an unconditional branch instruction at the end of the
// parent block. We want to replace that with an invoke call, so we can
// erase it now.
} else {
// This must be a catch-all. Split the block after the landingpad.
assert(CatchAction->getSelector()->isNullValue() && "expected catch-all");
- HandlerBB =
- StartBB->splitBasicBlock(StartBB->getFirstInsertionPt(), "catch.all");
+ HandlerBB = SplitBlock(StartBB, StartBB->getFirstInsertionPt(), DT);
}
IRBuilder<> Builder(HandlerBB->getFirstInsertionPt());
Function *EHCodeFn = Intrinsic::getDeclaration(
BB = NextBB;
}
- // For C++ EH, check if there is any interesting cleanup code before we
- // begin the catch. This is important because cleanups cannot rethrow
- // 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)
- findCleanupHandlers(Actions, BB, BB);
-
// Add the catch handler to the action list.
CatchHandler *Action = nullptr;
if (CatchHandlerMap.count(BB) && CatchHandlerMap[BB] != nullptr) {
Action = CatchHandlerMap[BB];
assert(Action->getSelector() == ExpectedSelector);
} else {
- // Since this is a catch-all handler, the selector won't actually appear
- // in the code anywhere. ExpectedSelector here is the constant null ptr
- // that we got from the landing pad instruction.
- Action = new CatchHandler(BB, ExpectedSelector, nullptr);
- CatchHandlerMap[BB] = Action;
+ // We don't expect a selector dispatch, but there may be a call to
+ // llvm.eh.begincatch, which separates catch handling code from
+ // cleanup code in the same control flow. This call looks for the
+ // begincatch intrinsic.
+ Action = findCatchHandler(BB, NextBB, VisitedBlocks);
+ if (Action) {
+ // For C++ EH, check if there is any interesting cleanup code before
+ // we begin the catch. This is important because cleanups cannot
+ // rethrow 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)
+ findCleanupHandlers(Actions, BB, BB);
+ } else {
+ // If an action was not found, it means that the control flows
+ // directly into the catch-all handler and there is no cleanup code.
+ // That's an expected situation and we must create a catch action.
+ // Since this is a catch-all handler, the selector won't actually
+ // appear in the code anywhere. ExpectedSelector here is the constant
+ // null ptr that we got from the landing pad instruction.
+ Action = new CatchHandler(BB, ExpectedSelector, nullptr);
+ CatchHandlerMap[BB] = Action;
+ }
}
Actions.insertCatchHandler(Action);
DEBUG(dbgs() << " Catch all handler at block " << BB->getName() << "\n");
// 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());
+ FinallyCall.getInstruction()->getNextNode() !=
+ BB->getTerminator()) {
+ SuccBB =
+ SplitBlock(BB, FinallyCall.getInstruction()->getNextNode(), DT);
} else {
if (FinallyCall.isInvoke()) {
- SuccBB = cast<InvokeInst>(FinallyCall.getInstruction())->getNormalDest();
+ SuccBB =
+ cast<InvokeInst>(FinallyCall.getInstruction())->getNormalDest();
} else {
SuccBB = BB->getUniqueSuccessor();
assert(SuccBB && "splitOutlinedFinallyCalls didn't insert a branch");
--- /dev/null
+; RUN: opt -mtriple=x86_64-pc-windows-msvc -winehprepare -S -o - < %s | FileCheck %s
+
+; This test is based on the following code:
+;
+; void test()
+; {
+; try {
+; Obj o;
+; may_throw();
+; } catch (...) {
+; }
+; }
+;
+; The purpose of this test is to verify that we create separate catch and
+; cleanup handlers. When compiling for the C++ 11 standard, this isn't
+; strictly necessary, since calling the destructor from the catch handler
+; would be logically equivalent to calling it from a cleanup handler.
+; However, if the -std=c++98 option is used, an exception in the cleanup
+; code should terminate the process (the MSVCRT runtime will do that) but
+; if the destructor is called from the catch handler, it wouldn't terminate
+; the process
+
+
+; ModuleID = 'cppeh-mixed-catch-and-cleanup.cpp'
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc"
+
+%class.Obj = type { i8 }
+
+; This just verifies that the function was processed by WinEHPrepare.
+;
+; CHECK-LABEL: define void @"\01?test@@YAXXZ"()
+; CHECK: entry:
+; CHECK: call void (...) @llvm.frameescape
+; CHECK: }
+
+; Function Attrs: nounwind uwtable
+define void @"\01?test@@YAXXZ"() #0 {
+entry:
+ %o = alloca %class.Obj, align 1
+ %exn.slot = alloca i8*
+ %ehselector.slot = alloca i32
+ invoke void @"\01?may_throw@@YAXXZ"()
+ to label %invoke.cont unwind label %lpad
+
+invoke.cont: ; preds = %entry
+ call void @"\01??1Obj@@QEAA@XZ"(%class.Obj* %o) #3
+ br label %try.cont
+
+lpad: ; preds = %entry
+ %0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*)
+ catch i8* null
+ %1 = extractvalue { i8*, i32 } %0, 0
+ store i8* %1, i8** %exn.slot
+ %2 = extractvalue { i8*, i32 } %0, 1
+ store i32 %2, i32* %ehselector.slot
+ call void @"\01??1Obj@@QEAA@XZ"(%class.Obj* %o) #3
+ %exn = load i8*, i8** %exn.slot
+ call void @llvm.eh.begincatch(i8* %exn, i8* null) #3
+ call void @llvm.eh.endcatch() #3
+ br label %try.cont
+
+try.cont: ; preds = %catch, %invoke.cont
+ ret void
+}
+
+; Verify that a cleanup handler was created and that it calls ~Obj().
+; CHECK-LABEL: define internal void @"\01?test@@YAXXZ.cleanup"(i8*, i8*)
+; CHECK: entry:
+; CHECK: @llvm.framerecover(i8* bitcast (void ()* @"\01?test@@YAXXZ" to i8*), i8* %1, i32 0)
+; CHECK: call void @"\01??1Obj@@QEAA@XZ"
+; CHECK: ret void
+; CHECK: }
+
+; Verify that a catch handler was created and that it does not call ~Obj().
+; CHECK-LABEL: define internal i8* @"\01?test@@YAXXZ.catch"(i8*, i8*)
+; CHECK: entry:
+; CHECK-NOT: call void @"\01??1Obj@@QEAA@XZ"
+; CHECK: ret i8* blockaddress(@"\01?test@@YAXXZ", %try.cont)
+; CHECK: }
+
+
+
+declare void @"\01?may_throw@@YAXXZ"() #1
+
+declare i32 @__CxxFrameHandler3(...)
+
+; Function Attrs: nounwind
+declare void @"\01??1Obj@@QEAA@XZ"(%class.Obj*) #2
+
+; Function Attrs: nounwind
+declare void @llvm.eh.begincatch(i8* nocapture, i8* nocapture) #3
+
+; Function Attrs: nounwind
+declare void @llvm.eh.endcatch() #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 = { "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 = { nounwind "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 }
+
+!llvm.module.flags = !{!0}
+!llvm.ident = !{!1}
+
+!0 = !{i32 1, !"PIC Level", i32 2}
+!1 = !{!"clang version 3.7.0 (trunk 235779) (llvm/trunk 235769)"}
projects / llvm / commitdiff