diff --git a/lib/CodeGen/AsmPrinter/WinException.cpp b/lib/CodeGen/AsmPrinter/WinException.cpp index 72f8a217c88..d9a55af08a6 100644 --- a/lib/CodeGen/AsmPrinter/WinException.cpp +++ b/lib/CodeGen/AsmPrinter/WinException.cpp @@ -72,17 +72,21 @@ void WinException::beginFunction(const MachineFunction *MF) { const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering(); unsigned PerEncoding = TLOF.getPersonalityEncoding(); - const Function *Per = nullptr; - if (F->hasPersonalityFn()) - Per = dyn_cast(F->getPersonalityFn()->stripPointerCasts()); - bool forceEmitPersonality = - F->hasPersonalityFn() && !isNoOpWithoutInvoke(classifyEHPersonality(Per)) && - F->needsUnwindTableEntry(); + EHPersonality Per = EHPersonality::Unknown; + const Function *PerFn = nullptr; + if (F->hasPersonalityFn()) { + PerFn = dyn_cast(F->getPersonalityFn()->stripPointerCasts()); + Per = classifyEHPersonality(PerFn); + } + + bool forceEmitPersonality = F->hasPersonalityFn() && + !isNoOpWithoutInvoke(Per) && + F->needsUnwindTableEntry(); shouldEmitPersonality = forceEmitPersonality || ((hasLandingPads || hasEHFunclets) && - PerEncoding != dwarf::DW_EH_PE_omit && Per); + PerEncoding != dwarf::DW_EH_PE_omit && PerFn); unsigned LSDAEncoding = TLOF.getLSDAEncoding(); shouldEmitLSDA = shouldEmitPersonality && @@ -90,7 +94,16 @@ void WinException::beginFunction(const MachineFunction *MF) { // If we're not using CFI, we don't want the CFI or the personality, but we // might want EH tables if we had EH pads. - if (!Asm->MAI->usesWindowsCFI() || (!MF->hasWinCFI() && !Per)) { + if (!Asm->MAI->usesWindowsCFI() || (!MF->hasWinCFI() && !PerFn)) { + if (Per == EHPersonality::MSVC_X86SEH && !hasEHFunclets) { + // If this is 32-bit SEH and we don't have any funclets (really invokes), + // make sure we emit the parent offset label. Some unreferenced filter + // functions may still refer to it. + const WinEHFuncInfo &FuncInfo = *MF->getWinEHFuncInfo(); + StringRef FLinkageName = + GlobalValue::getRealLinkageName(MF->getFunction()->getName()); + emitEHRegistrationOffsetLabel(FuncInfo, FLinkageName); + } shouldEmitLSDA = hasEHFunclets; shouldEmitPersonality = false; return; @@ -108,7 +121,7 @@ void WinException::endFunction(const MachineFunction *MF) { const Function *F = MF->getFunction(); EHPersonality Per = EHPersonality::Unknown; if (F->hasPersonalityFn()) - Per = classifyEHPersonality(F->getPersonalityFn()); + Per = classifyEHPersonality(F->getPersonalityFn()->stripPointerCasts()); // Get rid of any dead landing pads if we're not using funclets. In funclet // schemes, the landing pad is not actually reachable. It only exists so @@ -207,9 +220,7 @@ void WinException::beginFunclet(const MachineBasicBlock &MBB, TLOF.getCFIPersonalitySymbol(PerFn, Asm->TM, MMI); // Classify the personality routine so that we may reason about it. - EHPersonality Per = EHPersonality::Unknown; - if (F->hasPersonalityFn()) - Per = classifyEHPersonality(F->getPersonalityFn()); + EHPersonality Per = classifyEHPersonality(PerFn); // Do not emit a .seh_handler directive if it is a C++ cleanup funclet. if (Per != EHPersonality::MSVC_CXX || @@ -227,7 +238,7 @@ void WinException::endFunclet() { const Function *F = Asm->MF->getFunction(); EHPersonality Per = EHPersonality::Unknown; if (F->hasPersonalityFn()) - Per = classifyEHPersonality(F->getPersonalityFn()); + Per = classifyEHPersonality(F->getPersonalityFn()->stripPointerCasts()); // The .seh_handlerdata directive implicitly switches section, push the // current section so that we may return to it. @@ -905,15 +916,24 @@ void WinException::emitEHRegistrationOffsetLabel(const WinEHFuncInfo &FuncInfo, // registration in order to recover the parent frame pointer. Now that we know // we've code generated the parent, we can emit the label assignment that // those helpers use to get the offset of the registration node. + + // Compute the parent frame offset. The EHRegNodeFrameIndex will be invalid if + // after optimization all the invokes were eliminated. We still need to emit + // the parent frame offset label, but it should be garbage and should never be + // used. + int64_t Offset = 0; + int FI = FuncInfo.EHRegNodeFrameIndex; + if (FI != INT_MAX) { + const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering(); + unsigned UnusedReg; + Offset = TFI->getFrameIndexReference(*Asm->MF, FI, UnusedReg); + } + MCContext &Ctx = Asm->OutContext; MCSymbol *ParentFrameOffset = Ctx.getOrCreateParentFrameOffsetSymbol(FLinkageName); - unsigned UnusedReg; - const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering(); - int64_t Offset = TFI->getFrameIndexReference( - *Asm->MF, FuncInfo.EHRegNodeFrameIndex, UnusedReg); - const MCExpr *MCOffset = MCConstantExpr::create(Offset, Ctx); - Asm->OutStreamer->EmitAssignment(ParentFrameOffset, MCOffset); + Asm->OutStreamer->EmitAssignment(ParentFrameOffset, + MCConstantExpr::create(Offset, Ctx)); } /// Emit the language-specific data that _except_handler3 and 4 expect. This is diff --git a/test/CodeGen/X86/seh-no-invokes.ll b/test/CodeGen/X86/seh-no-invokes.ll new file mode 100644 index 00000000000..52244aa996a --- /dev/null +++ b/test/CodeGen/X86/seh-no-invokes.ll @@ -0,0 +1,76 @@ +; RUN: llc < %s | FileCheck %s + +; Generated with this C source: +; static __forceinline void __cpuid() { __asm__(""); } +; void f() { +; __try { +; __cpuid(); +; } __except (1) { +; } +; } + +; When running clang at -O1, we can end up deleting unreachable SEH catchpads +; without running GlobalDCE to remove the associated filter. This used to +; result in references to undefined labels. Now we check that we emit the +; label. This was PR30431. + +; CHECK-LABEL: _f: # @f +; CHECK: Lf$parent_frame_offset = 0 +; CHECK: retl + +; CHECK-LABEL: "?filt$0@0@f@@": # @"\01?filt$0@0@f@@" +; CHECK: movl $Lf$parent_frame_offset, + +; ModuleID = 't.c' +source_filename = "t.c" +target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32" +target triple = "i386-pc-windows-msvc19.0.24210" + +define void @f() #0 personality i8* bitcast (i32 (...)* @_except_handler3 to i8*) { +__try.cont: + %__exception_code = alloca i32, align 4 + call void (...) @llvm.localescape(i32* nonnull %__exception_code) + call void asm sideeffect "", "~{dirflag},~{fpsr},~{flags}"() #3, !srcloc !1 + ret void +} + +; Function Attrs: nounwind +define internal i32 @"\01?filt$0@0@f@@"() #1 { +entry: + %0 = tail call i8* @llvm.frameaddress(i32 1) + %1 = tail call i8* @llvm.x86.seh.recoverfp(i8* bitcast (void ()* @f to i8*), i8* %0) + %2 = tail call i8* @llvm.localrecover(i8* bitcast (void ()* @f to i8*), i8* %1, i32 0) + %__exception_code = bitcast i8* %2 to i32* + %3 = getelementptr inbounds i8, i8* %0, i32 -20 + %4 = bitcast i8* %3 to { i32*, i8* }** + %5 = load { i32*, i8* }*, { i32*, i8* }** %4, align 4 + %6 = getelementptr inbounds { i32*, i8* }, { i32*, i8* }* %5, i32 0, i32 0 + %7 = load i32*, i32** %6, align 4 + %8 = load i32, i32* %7, align 4 + store i32 %8, i32* %__exception_code, align 4 + ret i32 1 +} + +; Function Attrs: nounwind readnone +declare i8* @llvm.frameaddress(i32) #2 + +; Function Attrs: nounwind readnone +declare i8* @llvm.x86.seh.recoverfp(i8*, i8*) #2 + +; Function Attrs: nounwind readnone +declare i8* @llvm.localrecover(i8*, i8*, i32) #2 + +declare i32 @_except_handler3(...) + +; Function Attrs: nounwind +declare void @llvm.localescape(...) #3 + +attributes #0 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="pentium4" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" } +attributes #1 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="pentium4" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" } +attributes #2 = { nounwind readnone } +attributes #3 = { nounwind } + +!llvm.ident = !{!0} + +!0 = !{!"clang version 4.0.0 (trunk 282900) (llvm/trunk 282903)"} +!1 = !{i32 48}