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-rw-r--r--llvm/lib/CodeGen/WinEHPrepare.cpp112
-rw-r--r--llvm/test/CodeGen/WinEH/wineh-cleanuppad-nounwind.ll71
-rw-r--r--llvm/test/CodeGen/WinEH/wineh-cloning.ll4
-rw-r--r--llvm/test/CodeGen/WinEH/wineh-demotion.ll3
-rw-r--r--llvm/test/CodeGen/WinEH/wineh-no-demotion.ll2
5 files changed, 188 insertions, 4 deletions
diff --git a/llvm/lib/CodeGen/WinEHPrepare.cpp b/llvm/lib/CodeGen/WinEHPrepare.cpp
index 281fe934292..c4eaef88673 100644
--- a/llvm/lib/CodeGen/WinEHPrepare.cpp
+++ b/llvm/lib/CodeGen/WinEHPrepare.cpp
@@ -81,6 +81,7 @@ private:
void cloneCommonBlocks(Function &F);
void removeImplausibleInstructions(Function &F);
void cleanupPreparedFunclets(Function &F);
+ void fixupNoReturnCleanupPads(Function &F);
void verifyPreparedFunclets(Function &F);
// All fields are reset by runOnFunction.
@@ -656,6 +657,7 @@ void llvm::calculateClrEHStateNumbers(const Function *Fn,
void WinEHPrepare::colorFunclets(Function &F) {
BlockColors = colorEHFunclets(F);
+ FuncletBlocks.clear();
// Invert the map from BB to colors to color to BBs.
for (BasicBlock &BB : F) {
@@ -1001,6 +1003,114 @@ void WinEHPrepare::cleanupPreparedFunclets(Function &F) {
removeUnreachableBlocks(F);
}
+// Cleanuppads which are postdominated by unreachable will not unwind to any
+// catchswitches, making them dead. This is problematic if the original source
+// had a catch clause which could legitimately catch the exception, causing the
+// cleanup to run.
+//
+// This is only a problem for C++ where down-stream catches cause cleanups to
+// run.
+void WinEHPrepare::fixupNoReturnCleanupPads(Function &F) {
+ // We only need to do this for C++ personality routines,
+ // skip this work for all others.
+ if (Personality != EHPersonality::MSVC_CXX)
+ return;
+
+ // Do a quick sanity check on the color map before we throw it away so as to
+ // avoid hiding latent bugs.
+ DEBUG(verifyPreparedFunclets(F));
+ // Re-color the funclets because cleanupPreparedFunclets might have
+ // invalidated FuncletBlocks.
+ colorFunclets(F);
+
+ // We create a unique catchswitch for each parent it will be nested within.
+ SmallDenseMap<Value *, CatchSwitchInst *> NewCatchSwitches;
+ // Create a new catchswitch+catchpad where the catchpad is post-dominated by
+ // unreachable.
+ auto GetOrCreateCatchSwitch = [&](Value *ParentPad) {
+ auto &CatchSwitch = NewCatchSwitches[ParentPad];
+ if (CatchSwitch)
+ return CatchSwitch;
+
+ auto *ParentBB = isa<ConstantTokenNone>(ParentPad)
+ ? &F.getEntryBlock()
+ : cast<Instruction>(ParentPad)->getParent();
+
+ StringRef NameSuffix = ParentBB->getName();
+
+ BasicBlock *CatchSwitchBB = BasicBlock::Create(
+ F.getContext(), Twine("catchswitchbb.for.", NameSuffix));
+ CatchSwitchBB->insertInto(&F, ParentBB->getNextNode());
+ CatchSwitch = CatchSwitchInst::Create(ParentPad, /*UnwindDest=*/nullptr,
+ /*NumHandlers=*/1,
+ Twine("catchswitch.for.", NameSuffix),
+ CatchSwitchBB);
+
+ BasicBlock *CatchPadBB = BasicBlock::Create(
+ F.getContext(), Twine("catchpadbb.for.", NameSuffix));
+ CatchPadBB->insertInto(&F, CatchSwitchBB->getNextNode());
+ Value *CatchPadArgs[] = {
+ Constant::getNullValue(Type::getInt8PtrTy(F.getContext())),
+ ConstantInt::get(Type::getInt32Ty(F.getContext()), 64),
+ Constant::getNullValue(Type::getInt8PtrTy(F.getContext())),
+ };
+ CatchPadInst::Create(CatchSwitch, CatchPadArgs,
+ Twine("catchpad.for.", NameSuffix), CatchPadBB);
+ new UnreachableInst(F.getContext(), CatchPadBB);
+
+ CatchSwitch->addHandler(CatchPadBB);
+
+ return CatchSwitch;
+ };
+
+ // Look for all basic blocks which are within cleanups which are postdominated
+ // by unreachable.
+ for (auto &Funclets : FuncletBlocks) {
+ BasicBlock *FuncletPadBB = Funclets.first;
+ auto *CleanupPad = dyn_cast<CleanupPadInst>(FuncletPadBB->getFirstNonPHI());
+ // Skip over any non-cleanup funclets.
+ if (!CleanupPad)
+ continue;
+ // Skip over any cleanups have unwind targets, they do not need this.
+ if (getCleanupRetUnwindDest(CleanupPad) != nullptr)
+ continue;
+ // Walk the blocks within the cleanup which end in 'unreachable'.
+ // We will replace the unreachable instruction with a cleanupret;
+ // this cleanupret will unwind to a catchswitch with a lone catch-all
+ // catchpad.
+ std::vector<BasicBlock *> &BlocksInFunclet = Funclets.second;
+ for (BasicBlock *BB : BlocksInFunclet) {
+ auto *UI = dyn_cast<UnreachableInst>(BB->getTerminator());
+ if (!UI)
+ continue;
+ // Remove the unreachable instruction.
+ UI->eraseFromParent();
+
+ // Add our new cleanupret.
+ auto *ParentPad = CleanupPad->getParentPad();
+ CatchSwitchInst *CatchSwitch = GetOrCreateCatchSwitch(ParentPad);
+ CleanupReturnInst::Create(CleanupPad, CatchSwitch->getParent(), BB);
+ }
+ }
+
+ // Update BlockColors and FuncletBlocks to maintain WinEHPrepare's
+ // invariants.
+ for (auto CatchSwitchKV : NewCatchSwitches) {
+ CatchSwitchInst *CatchSwitch = CatchSwitchKV.second;
+ BasicBlock *CatchSwitchBB = CatchSwitch->getParent();
+
+ assert(CatchSwitch->getNumSuccessors() == 1);
+ BasicBlock *CatchPadBB = CatchSwitch->getSuccessor(0);
+ assert(isa<CatchPadInst>(CatchPadBB->getFirstNonPHI()));
+
+ BlockColors.insert({CatchSwitchBB, ColorVector(CatchSwitchBB)});
+ FuncletBlocks[CatchSwitchBB] = {CatchSwitchBB};
+
+ BlockColors.insert({CatchPadBB, ColorVector(CatchPadBB)});
+ FuncletBlocks[CatchPadBB] = {CatchPadBB};
+ }
+}
+
void WinEHPrepare::verifyPreparedFunclets(Function &F) {
for (BasicBlock &BB : F) {
size_t NumColors = BlockColors[&BB].size();
@@ -1036,6 +1146,8 @@ bool WinEHPrepare::prepareExplicitEH(Function &F) {
cleanupPreparedFunclets(F);
}
+ fixupNoReturnCleanupPads(F);
+
DEBUG(verifyPreparedFunclets(F));
// Recolor the CFG to verify that all is well.
DEBUG(colorFunclets(F));
diff --git a/llvm/test/CodeGen/WinEH/wineh-cleanuppad-nounwind.ll b/llvm/test/CodeGen/WinEH/wineh-cleanuppad-nounwind.ll
new file mode 100644
index 00000000000..09b4d3b8a1b
--- /dev/null
+++ b/llvm/test/CodeGen/WinEH/wineh-cleanuppad-nounwind.ll
@@ -0,0 +1,71 @@
+; RUN: opt -S -winehprepare < %s | FileCheck %s
+target triple = "x86_64-pc-windows-msvc"
+
+; CHECK-LABEL: @test1(
+define void @test1(i1 %b) personality i32 (...)* @__CxxFrameHandler3 {
+entry:
+ invoke void @f()
+ to label %try.cont unwind label %cleanup.bb
+
+; CHECK: entry:
+
+; CHECK: [[catchswitch_entry:.*]]:
+; CHECK-NEXT: %[[cs0:.*]] = catchswitch within none [label %[[catchpad:.*]]] unwind to caller
+; CHECK: [[catchpad]]:
+; CHECK-NEXT: %[[cp0:.*]] = catchpad within %[[cs0]] [i8* null, i32 64, i8* null]
+; CHECK-NEXT: unreachable
+
+try.cont:
+ invoke void @f()
+ to label %exit unwind label %catchswitch.bb
+
+cleanup.bb:
+ %cleanup = cleanuppad within none []
+ br i1 %b, label %left, label %right
+
+left:
+ call void @exit(i32 0) [ "funclet"(token %cleanup) ]
+ unreachable
+
+right:
+ call void @exit(i32 1) [ "funclet"(token %cleanup) ]
+ unreachable
+
+catchswitch.bb:
+ %cs = catchswitch within none [label %catchpad.bb] unwind to caller
+
+; CHECK: catchpad.bb:
+; CHECK-NEXT: %catch = catchpad within %cs [i8* null, i32 64, i8* null]
+
+; CHECK: [[catchswitch_catch:.*]]:
+; CHECK-NEXT: %[[cs1:.*]] = catchswitch within %catch [label %[[catchpad_catch:.*]]] unwind to caller
+; CHECK: [[catchpad_catch]]:
+; CHECK-NEXT: %[[cp1:.*]] = catchpad within %[[cs1]] [i8* null, i32 64, i8* null]
+; CHECK-NEXT: unreachable
+
+; CHECK: nested.cleanup.bb:
+; CHECK-NEXT: %nested.cleanup = cleanuppad within %catch []
+; CHECK-NEXT: call void @exit(i32 2) [ "funclet"(token %nested.cleanup) ]
+; CHECK-NEXT: cleanupret from %nested.cleanup unwind label %[[catchswitch_catch]]
+
+catchpad.bb:
+ %catch = catchpad within %cs [i8* null, i32 64, i8* null]
+ invoke void @f() [ "funclet"(token %catch) ]
+ to label %unreachable unwind label %nested.cleanup.bb
+
+nested.cleanup.bb:
+ %nested.cleanup = cleanuppad within %catch []
+ call void @exit(i32 2) [ "funclet"(token %nested.cleanup) ]
+ unreachable
+
+unreachable:
+ unreachable
+
+exit:
+ unreachable
+}
+
+declare void @f()
+declare void @exit(i32) nounwind noreturn
+
+declare i32 @__CxxFrameHandler3(...)
diff --git a/llvm/test/CodeGen/WinEH/wineh-cloning.ll b/llvm/test/CodeGen/WinEH/wineh-cloning.ll
index 748c07df173..355ffa8c3f6 100644
--- a/llvm/test/CodeGen/WinEH/wineh-cloning.ll
+++ b/llvm/test/CodeGen/WinEH/wineh-cloning.ll
@@ -44,7 +44,7 @@ noreturn:
; CHECK: call void @llvm.foo(i32 %x)
-define void @test2() personality i32 (...)* @__CxxFrameHandler3 {
+define void @test2() personality i32 (...)* @__C_specific_handler {
entry:
invoke void @f()
to label %exit unwind label %cleanup
@@ -71,7 +71,7 @@ exit:
; CHECK-NEXT: ret void
-define void @test3() personality i32 (...)* @__CxxFrameHandler3 {
+define void @test3() personality i32 (...)* @__C_specific_handler {
entry:
invoke void @f()
to label %invoke.cont unwind label %catch.switch
diff --git a/llvm/test/CodeGen/WinEH/wineh-demotion.ll b/llvm/test/CodeGen/WinEH/wineh-demotion.ll
index 411952d84bb..048466a26d1 100644
--- a/llvm/test/CodeGen/WinEH/wineh-demotion.ll
+++ b/llvm/test/CodeGen/WinEH/wineh-demotion.ll
@@ -1,6 +1,7 @@
; RUN: opt -mtriple=x86_64-pc-windows-msvc -S -winehprepare < %s | FileCheck %s
declare i32 @__CxxFrameHandler3(...)
+declare i32 @__C_specific_handler(...)
declare void @f()
@@ -327,7 +328,7 @@ exit:
}
; CHECK-LABEL: @test8(
-define void @test8() personality i32 (...)* @__CxxFrameHandler3 { entry:
+define void @test8() personality i32 (...)* @__C_specific_handler { entry:
invoke void @f()
to label %done unwind label %cleanup1
invoke void @f()
diff --git a/llvm/test/CodeGen/WinEH/wineh-no-demotion.ll b/llvm/test/CodeGen/WinEH/wineh-no-demotion.ll
index 0901e27c301..277dd5c0e6a 100644
--- a/llvm/test/CodeGen/WinEH/wineh-no-demotion.ll
+++ b/llvm/test/CodeGen/WinEH/wineh-no-demotion.ll
@@ -1,4 +1,4 @@
-; RUN: opt -mtriple=x86_x64-pc-windows-msvc -S -winehprepare -disable-demotion -disable-cleanups < %s | FileCheck %s
+; RUN: opt -mtriple=x86_64-pc-windows-msvc -S -winehprepare -disable-demotion -disable-cleanups < %s | FileCheck %s
declare i32 @__CxxFrameHandler3(...)
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