[WinEH] Add codegen support for cleanuppad and cleanupret
All of the complexity is in cleanupret, and it mostly follows the same
codepaths as catchret, except it doesn't take a return value in RAX.
This small example now compiles and executes successfully on win32:
extern "C" int printf(const char *, ...) noexcept;
struct Dtor {
~Dtor() { printf("~Dtor\n"); }
};
void has_cleanup() {
Dtor o;
throw 42;
}
int main() {
try {
has_cleanup();
} catch (int) {
printf("caught it\n");
}
}
Don't try to put the cleanup in the same function as the catch, or Bad
Things will happen.
llvm-svn: 247219
diff --git a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
index e706d73d..0953158 100644
--- a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
@@ -316,10 +316,11 @@
/// Retreive the MCSymbol for a GlobalValue or MachineBasicBlock. GlobalValues
/// are used in the old WinEH scheme, and they will be removed eventually.
static MCSymbol *getMCSymbolForMBBOrGV(AsmPrinter *Asm, ValueOrMBB Handler) {
+ if (!Handler)
+ return nullptr;
if (Handler.is<MachineBasicBlock *>())
return Handler.get<MachineBasicBlock *>()->getSymbol();
- else
- return Asm->getSymbol(cast<GlobalValue>(Handler.get<const Value *>()));
+ return Asm->getSymbol(cast<GlobalValue>(Handler.get<const Value *>()));
}
void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
@@ -404,8 +405,9 @@
if (UnwindMapXData) {
OS.EmitLabel(UnwindMapXData);
for (const WinEHUnwindMapEntry &UME : FuncInfo.UnwindMap) {
- OS.EmitIntValue(UME.ToState, 4); // ToState
- OS.EmitValue(create32bitRef(UME.Cleanup), 4); // Action
+ MCSymbol *CleanupSym = getMCSymbolForMBBOrGV(Asm, UME.Cleanup);
+ OS.EmitIntValue(UME.ToState, 4); // ToState
+ OS.EmitValue(create32bitRef(CleanupSym), 4); // Action
}
}
diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 15793f6..fe35977 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -223,8 +223,6 @@
assert(&*BB->begin() == I &&
"WinEHPrepare failed to remove PHIs from imaginary BBs");
continue;
- } else if (!isa<LandingPadInst>(I)) {
- llvm_unreachable("unhandled EH pad in MBB graph");
}
}
@@ -269,7 +267,7 @@
SmallVector<const LandingPadInst *, 4> LPads;
for (BB = Fn->begin(); BB != EB; ++BB) {
const Instruction *FNP = BB->getFirstNonPHI();
- if (BB->isEHPad() && !isa<CatchPadInst>(FNP) && !isa<CatchEndPadInst>(FNP))
+ if (BB->isEHPad() && MBBMap.count(BB))
MBBMap[BB]->setIsEHPad();
if (const auto *LPI = dyn_cast<LandingPadInst>(FNP))
LPads.push_back(LPI);
@@ -289,24 +287,27 @@
// Calculate state numbers if we haven't already.
WinEHFuncInfo &EHInfo = MMI.getWinEHFuncInfo(&fn);
- if (Personality == EHPersonality::MSVC_CXX) {
- const Function *WinEHParentFn = MMI.getWinEHParent(&fn);
+ const Function *WinEHParentFn = MMI.getWinEHParent(&fn);
+ if (Personality == EHPersonality::MSVC_CXX)
calculateWinCXXEHStateNumbers(WinEHParentFn, EHInfo);
- } else {
- const Function *WinEHParentFn = MMI.getWinEHParent(&fn);
+ else
calculateSEHStateNumbers(WinEHParentFn, EHInfo);
+
+ // Map all BB references in the WinEH data to MBBs.
+ for (WinEHTryBlockMapEntry &TBME : EHInfo.TryBlockMap)
+ for (WinEHHandlerType &H : TBME.HandlerArray)
+ if (const auto *BB =
+ dyn_cast<BasicBlock>(H.Handler.get<const Value *>()))
+ H.Handler = MBBMap[BB];
+ for (WinEHUnwindMapEntry &UME : EHInfo.UnwindMap)
+ if (UME.Cleanup)
+ if (const auto *BB = dyn_cast<BasicBlock>(UME.Cleanup.get<const Value *>()))
+ UME.Cleanup = MBBMap[BB];
+ for (SEHUnwindMapEntry &UME : EHInfo.SEHUnwindMap) {
+ const BasicBlock *BB = UME.Handler.get<const BasicBlock *>();
+ UME.Handler = MBBMap[BB];
}
- // Map all BB references in the EH data to MBBs.
- for (WinEHTryBlockMapEntry &TBME : EHInfo.TryBlockMap)
- for (WinEHHandlerType &H : TBME.HandlerArray)
- if (const auto *BB =
- dyn_cast<BasicBlock>(H.Handler.get<const Value *>()))
- H.Handler = MBBMap[BB];
- for (SEHUnwindMapEntry &UME : EHInfo.SEHUnwindMap) {
- const BasicBlock *BB = UME.Handler.get<const BasicBlock *>();
- UME.Handler = MBBMap[BB];
- }
// If there's an explicit EH registration node on the stack, record its
// frame index.
if (EHInfo.EHRegNode && EHInfo.EHRegNode->getParent()->getParent() == Fn) {
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 6fba18d..2885776 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1165,9 +1165,8 @@
void SelectionDAGBuilder::visitCatchRet(const CatchReturnInst &I) {
// Update machine-CFG edge.
- MachineBasicBlock *PadMBB = FuncInfo.MBB;
MachineBasicBlock *TargetMBB = FuncInfo.MBBMap[I.getSuccessor()];
- PadMBB->addSuccessor(TargetMBB);
+ FuncInfo.MBB->addSuccessor(TargetMBB);
// Create the terminator node.
SDValue Ret = DAG.getNode(ISD::CATCHRET, getCurSDLoc(), MVT::Other,
@@ -1180,11 +1179,64 @@
}
void SelectionDAGBuilder::visitCleanupPad(const CleanupPadInst &CPI) {
- report_fatal_error("visitCleanupPad not yet implemented!");
+ // Don't emit any special code for the cleanuppad instruction. It just marks
+ // the start of a funclet.
+ FuncInfo.MBB->setIsEHFuncletEntry();
+}
+
+/// When an invoke or a cleanupret unwinds to the next EH pad, there are
+/// many places it could ultimately go. In the IR, we have a single unwind
+/// destination, but in the machine CFG, we enumerate all the possible blocks.
+/// This function skips over imaginary basic blocks that hold catchpad,
+/// terminatepad, or catchendpad instructions, and finds all the "real" machine
+/// basic block destinations.
+static void
+findUnwindDestinations(FunctionLoweringInfo &FuncInfo,
+ const BasicBlock *EHPadBB,
+ SmallVectorImpl<MachineBasicBlock *> &UnwindDests) {
+ bool IsMSVCCXX = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn()) ==
+ EHPersonality::MSVC_CXX;
+ while (EHPadBB) {
+ const Instruction *Pad = EHPadBB->getFirstNonPHI();
+ if (isa<LandingPadInst>(Pad)) {
+ // Stop on landingpads. They are not funclets.
+ UnwindDests.push_back(FuncInfo.MBBMap[EHPadBB]);
+ break;
+ } else if (isa<CleanupPadInst>(Pad) || isa<LandingPadInst>(Pad)) {
+ // Stop on cleanup pads. Cleanups are always funclet entries for all known
+ // personalities.
+ UnwindDests.push_back(FuncInfo.MBBMap[EHPadBB]);
+ UnwindDests.back()->setIsEHFuncletEntry();
+ break;
+ } else if (const auto *CPI = dyn_cast<CatchPadInst>(Pad)) {
+ // Add the catchpad handler to the possible destinations.
+ UnwindDests.push_back(FuncInfo.MBBMap[CPI->getNormalDest()]);
+ // In MSVC C++, catchblocks are funclets and need prologues.
+ if (IsMSVCCXX)
+ UnwindDests.back()->setIsEHFuncletEntry();
+ EHPadBB = CPI->getUnwindDest();
+ } else if (const auto *CEPI = dyn_cast<CatchEndPadInst>(Pad)) {
+ EHPadBB = CEPI->getUnwindDest();
+ } else if (const auto *CEPI = dyn_cast<CleanupEndPadInst>(Pad)) {
+ EHPadBB = CEPI->getUnwindDest();
+ }
+ }
}
void SelectionDAGBuilder::visitCleanupRet(const CleanupReturnInst &I) {
- report_fatal_error("visitCleanupRet not yet implemented!");
+ // Update successor info.
+ // FIXME: The weights for catchpads will be wrong.
+ SmallVector<MachineBasicBlock *, 1> UnwindDests;
+ findUnwindDestinations(FuncInfo, I.getUnwindDest(), UnwindDests);
+ for (MachineBasicBlock *UnwindDest : UnwindDests) {
+ UnwindDest->setIsEHPad();
+ addSuccessorWithWeight(FuncInfo.MBB, UnwindDest);
+ }
+
+ // Create the terminator node.
+ SDValue Ret =
+ DAG.getNode(ISD::CLEANUPRET, getCurSDLoc(), MVT::Other, getControlRoot());
+ DAG.setRoot(Ret);
}
void SelectionDAGBuilder::visitCleanupEndPad(const CleanupEndPadInst &I) {
@@ -2020,37 +2072,8 @@
CopyToExportRegsIfNeeded(&I);
}
- // Stop when we hit a pad that generates real code or we unwind to caller.
- // Catchpads are conditional branches that add real MBB destinations and
- // continue the loop. EH "end" pads are not real BBs and simply continue.
SmallVector<MachineBasicBlock *, 1> UnwindDests;
- bool IsMSVCCXX = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn()) ==
- EHPersonality::MSVC_CXX;
- while (EHPadBB) {
- const Instruction *Pad = EHPadBB->getFirstNonPHI();
- if (isa<LandingPadInst>(Pad)) {
- // Stop on landingpads. They are not funclets.
- UnwindDests.push_back(FuncInfo.MBBMap[EHPadBB]);
- break;
- } else if (isa<CleanupPadInst>(Pad) || isa<LandingPadInst>(Pad)) {
- // Stop on cleanup pads. Cleanups are always funclet entries for all known
- // personalities.
- UnwindDests.push_back(FuncInfo.MBBMap[EHPadBB]);
- UnwindDests.back()->setIsEHFuncletEntry();
- break;
- } else if (const auto *CPI = dyn_cast<CatchPadInst>(Pad)) {
- // Add the catchpad handler to the possible destinations.
- UnwindDests.push_back(FuncInfo.MBBMap[CPI->getNormalDest()]);
- // In MSVC C++, catchblocks are funclets and need prologues.
- if (IsMSVCCXX)
- UnwindDests.back()->setIsEHFuncletEntry();
- EHPadBB = CPI->getUnwindDest();
- } else if (const auto *CEPI = dyn_cast<CatchEndPadInst>(Pad)) {
- EHPadBB = CEPI->getUnwindDest();
- } else if (const auto *CEPI = dyn_cast<CleanupEndPadInst>(Pad)) {
- EHPadBB = CEPI->getUnwindDest();
- }
- }
+ findUnwindDestinations(FuncInfo, EHPadBB, UnwindDests);
// Update successor info.
// FIXME: The weights for catchpads will be wrong.
diff --git a/llvm/lib/CodeGen/WinEHPrepare.cpp b/llvm/lib/CodeGen/WinEHPrepare.cpp
index ed3cd5d..ea43cb2 100644
--- a/llvm/lib/CodeGen/WinEHPrepare.cpp
+++ b/llvm/lib/CodeGen/WinEHPrepare.cpp
@@ -3053,7 +3053,7 @@
}
static int addSEHHandler(WinEHFuncInfo &FuncInfo, int ParentState,
- const Function *Filter, const BasicBlock *Handler) {
+ const Function *Filter, const BasicBlock *Handler) {
SEHUnwindMapEntry Entry;
Entry.ToState = ParentState;
Entry.Filter = Filter;