https://github.com/GkvJwa updated https://github.com/llvm/llvm-project/pull/180144
>From 9d1f31eb3a551d1f718557ac83a87e19450db331 Mon Sep 17 00:00:00 2001 From: GkvJwa <[email protected]> Date: Tue, 24 Mar 2026 22:04:17 +0800 Subject: [PATCH 1/6] Add test --- clang/lib/CodeGen/CGCleanup.cpp | 23 ++++++---- clang/lib/CodeGen/CGCleanup.h | 7 ++++ clang/lib/CodeGen/CGException.cpp | 6 ++- clang/lib/CodeGen/EHScopeStack.h | 3 ++ .../CodeGen/windows-seh-EHa-TryInFinally.cpp | 42 ++++++++++++++++--- 5 files changed, 65 insertions(+), 16 deletions(-) diff --git a/clang/lib/CodeGen/CGCleanup.cpp b/clang/lib/CodeGen/CGCleanup.cpp index 3d242bec73126..c33f057688b1a 100644 --- a/clang/lib/CodeGen/CGCleanup.cpp +++ b/clang/lib/CodeGen/CGCleanup.cpp @@ -159,6 +159,7 @@ void *EHScopeStack::pushCleanup(CleanupKind Kind, size_t Size) { bool IsEHCleanup = Kind & EHCleanup; bool IsLifetimeMarker = Kind & LifetimeMarker; bool IsFakeUse = Kind & FakeUse; + bool IsSEHFinallyCleanup = Kind & SEHFinallyCleanup; // Per C++ [except.terminate], it is implementation-defined whether none, // some, or all cleanups are called before std::terminate. Thus, when @@ -183,6 +184,8 @@ void *EHScopeStack::pushCleanup(CleanupKind Kind, size_t Size) { Scope->setLifetimeMarker(); if (IsFakeUse) Scope->setFakeUse(); + if (IsSEHFinallyCleanup) + Scope->setSEHFinallyCleanup(); // With Windows -EHa, Invoke llvm.seh.scope.begin() for EHCleanup // If exceptions are disabled/ignored and SEH is not in use, then there is no @@ -191,7 +194,8 @@ void *EHScopeStack::pushCleanup(CleanupKind Kind, size_t Size) { // consistent with MSVC's behavior, except in the presence of -EHa. // Check getInvokeDest() to generate llvm.seh.scope.begin() as needed. if (CGF->getLangOpts().EHAsynch && IsEHCleanup && !IsLifetimeMarker && - CGF->getTarget().getCXXABI().isMicrosoft() && CGF->getInvokeDest()) + !IsSEHFinallyCleanup && CGF->getTarget().getCXXABI().isMicrosoft() && + CGF->getInvokeDest()) CGF->EmitSehCppScopeBegin(); return Scope->getCleanupBuffer(); @@ -785,6 +789,8 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough, // Under -EHa, invoke seh.scope.end() to mark scope end before dtor bool IsEHa = getLangOpts().EHAsynch && !Scope.isLifetimeMarker(); + // Save IsSEHFinallyCleanup before any popCleanup() invalidates Scope. + bool IsSEHFinallyCleanup = Scope.isSEHFinallyCleanup(); const EHPersonality &Personality = EHPersonality::get(*this); if (!RequiresNormalCleanup) { // Mark CPP scope end for passed-by-value Arg temp @@ -811,10 +817,10 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough, // mark SEH scope end for fall-through flow if (IsEHa && getInvokeDest()) { - if (Personality.isMSVCXXPersonality()) - EmitSehCppScopeEnd(); - else + if (Scope.isSEHFinallyCleanup()) EmitSehTryScopeEnd(); + else if (Personality.isMSVCPersonality()) + EmitSehCppScopeEnd(); } destroyOptimisticNormalEntry(*this, Scope); @@ -853,10 +859,10 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough, // intercept normal cleanup to mark SEH scope end if (IsEHa && getInvokeDest()) { - if (Personality.isMSVCXXPersonality()) - EmitSehCppScopeEnd(); - else + if (Scope.isSEHFinallyCleanup()) EmitSehTryScopeEnd(); + else if (Personality.isMSVCPersonality()) + EmitSehCppScopeEnd(); } // III. Figure out where we're going and build the cleanup @@ -1056,7 +1062,8 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough, EHStack.pushTerminate(); PushedTerminate = true; } else if (IsEHa && getInvokeDest()) { - EmitSehCppScopeEnd(); + if (!IsSEHFinallyCleanup) + EmitSehCppScopeEnd(); } // We only actually emit the cleanup code if the cleanup is either diff --git a/clang/lib/CodeGen/CGCleanup.h b/clang/lib/CodeGen/CGCleanup.h index ba78e5478ac37..ded8be13c5fae 100644 --- a/clang/lib/CodeGen/CGCleanup.h +++ b/clang/lib/CodeGen/CGCleanup.h @@ -99,6 +99,9 @@ class EHScope { LLVM_PREFERRED_TYPE(bool) unsigned TestFlagInEHCleanup : 1; + LLVM_PREFERRED_TYPE(bool) + unsigned IsSEHFinallyCleanup : 1; + /// The amount of extra storage needed by the Cleanup. /// Always a multiple of the scope-stack alignment. unsigned CleanupSize : 12; @@ -357,6 +360,7 @@ class alignas(8) EHCleanupScope : public EHScope { CleanupBits.IsActive = true; CleanupBits.IsLifetimeMarker = false; CleanupBits.IsFakeUse = false; + CleanupBits.IsSEHFinallyCleanup = false; CleanupBits.TestFlagInNormalCleanup = false; CleanupBits.TestFlagInEHCleanup = false; CleanupBits.CleanupSize = cleanupSize; @@ -392,6 +396,9 @@ class alignas(8) EHCleanupScope : public EHScope { bool isFakeUse() const { return CleanupBits.IsFakeUse; } void setFakeUse() { CleanupBits.IsFakeUse = true; } + bool isSEHFinallyCleanup() const { return CleanupBits.IsSEHFinallyCleanup; } + void setSEHFinallyCleanup() { CleanupBits.IsSEHFinallyCleanup = true; } + bool hasActiveFlag() const { return ActiveFlag.isValid(); } Address getActiveFlag() const { return ActiveFlag; diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp index 7559727721496..fcbb473228c01 100644 --- a/clang/lib/CodeGen/CGException.cpp +++ b/clang/lib/CodeGen/CGException.cpp @@ -2182,7 +2182,8 @@ llvm::Value *CodeGenFunction::EmitSEHAbnormalTermination() { void CodeGenFunction::pushSEHCleanup(CleanupKind Kind, llvm::Function *FinallyFunc) { - EHStack.pushCleanup<PerformSEHFinally>(Kind, FinallyFunc); + EHStack.pushCleanup<PerformSEHFinally>( + static_cast<CleanupKind>(Kind | SEHFinallyCleanup), FinallyFunc); } void CodeGenFunction::EnterSEHTryStmt(const SEHTryStmt &S) { @@ -2194,7 +2195,8 @@ void CodeGenFunction::EnterSEHTryStmt(const SEHTryStmt &S) { HelperCGF.GenerateSEHFinallyFunction(*this, *Finally); // Push a cleanup for __finally blocks. - EHStack.pushCleanup<PerformSEHFinally>(NormalAndEHCleanup, FinallyFunc); + EHStack.pushCleanup<PerformSEHFinally>(NormalAndEHSEHFinallyCleanup, + FinallyFunc); return; } diff --git a/clang/lib/CodeGen/EHScopeStack.h b/clang/lib/CodeGen/EHScopeStack.h index b9b8021191d62..2f5e056e7db3b 100644 --- a/clang/lib/CodeGen/EHScopeStack.h +++ b/clang/lib/CodeGen/EHScopeStack.h @@ -92,6 +92,9 @@ enum CleanupKind : unsigned { // markers chiefly to be ignored in most contexts. FakeUse = 0x10, NormalFakeUse = FakeUse | NormalCleanup, + + SEHFinallyCleanup = 0x20, + NormalAndEHSEHFinallyCleanup = SEHFinallyCleanup | NormalAndEHCleanup, }; /// A stack of scopes which respond to exceptions, including cleanups diff --git a/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp b/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp index 462ba9afb5b30..3301178f32b49 100644 --- a/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp +++ b/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp @@ -43,11 +43,11 @@ int main() { } // CHECK-LABEL:@"?foo@@YAXXZ"() -// CHECK: invoke.cont: // CHECK: invoke void @llvm.seh.try.begin() +// CHECK: invoke.cont: // CHECK: store volatile i32 1, ptr %cleanup.dest.slot // CHECK: invoke void @llvm.seh.try.end() -// CHECK: invoke.cont2: +// CHECK: invoke.cont1: // CHECK: %cleanup.dest = load i32, ptr %cleanup.dest.slot // CHECK: %1 = icmp ne i32 %cleanup.dest, 0 // CHECK: %2 = zext i1 %1 to i8 @@ -69,14 +69,13 @@ void foo() } // CHECK-LABEL:@"?bar@@YAHXZ"() -// CHECK: invoke.cont: // CHECK: invoke void @llvm.seh.try.begin() -// CHECK: invoke.cont1: +// CHECK: invoke.cont: // CHECK: store volatile i32 1, ptr %cleanup.dest.slot // CHECK: invoke void @llvm.seh.try.end() -// CHECK: invoke.cont2: +// CHECK: invoke.cont1: // CHECK: call void @"?fin$0@0@bar@@" -// CHECK: %cleanup.dest3 = load i32, ptr %cleanup.dest.slot +// CHECK: %cleanup.dest2 = load i32, ptr %cleanup.dest.slot // CHECK: return: // CHECK: ret i32 11 int bar() @@ -90,3 +89,34 @@ int bar() } } } + +// CHECK-LABEL: @"?foo1@@YAXXZ"() +// CHECK-NOT: invoke void @llvm.seh.scope.begin() +// CHECK: invoke void @llvm.seh.try.begin() +// CHECK: invoke.cont: +// CHECK: invoke void @llvm.seh.scope.begin() +// CHECK: store volatile ptr %call, ptr %a, align 8 +// CHECK: invoke void @llvm.seh.scope.begin() +// CHECK: invoke void @"??1A@@QEAA@XZ" +// CHECK: invoke void @llvm.seh.scope.end() +// CHECK-NOT: invoke void @llvm.seh.try.end() +// CHECK: br label %delete.end +// CHECK: invoke void @llvm.seh.try.end() +// CHECK: call void @"?fin$0@0@foo1@@"(i8 noundef 0 +// CHECK: cleanupret +// CHECK: call void @"?fin$0@0@foo1@@"(i8 noundef 1 +// CHECK-NOT: @llvm.seh.scope.end +// CHECK: cleanupret +struct A { + A(); + ~A(); +}; + +void foo1() { + __try { + A* a = new A; + delete a; + } + __finally { + } +} >From aae06618f6d222beb492016e71c34c405b9dd296 Mon Sep 17 00:00:00 2001 From: GkvJwa <[email protected]> Date: Tue, 24 Mar 2026 22:26:16 +0800 Subject: [PATCH 2/6] 2 --- clang/lib/CodeGen/CGCleanup.cpp | 4 ++-- clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp | 3 ++- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/clang/lib/CodeGen/CGCleanup.cpp b/clang/lib/CodeGen/CGCleanup.cpp index c33f057688b1a..b7130ff8578e1 100644 --- a/clang/lib/CodeGen/CGCleanup.cpp +++ b/clang/lib/CodeGen/CGCleanup.cpp @@ -789,7 +789,6 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough, // Under -EHa, invoke seh.scope.end() to mark scope end before dtor bool IsEHa = getLangOpts().EHAsynch && !Scope.isLifetimeMarker(); - // Save IsSEHFinallyCleanup before any popCleanup() invalidates Scope. bool IsSEHFinallyCleanup = Scope.isSEHFinallyCleanup(); const EHPersonality &Personality = EHPersonality::get(*this); if (!RequiresNormalCleanup) { @@ -801,7 +800,8 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough, // block. if (NormalDeactivateOrigIP.isSet()) Builder.restoreIP(NormalDeactivateOrigIP); - if (Personality.isMSVCXXPersonality() && Builder.GetInsertBlock()) + if (Personality.isMSVCPersonality() && Builder.GetInsertBlock() && + !IsSEHFinallyCleanup) EmitSehCppScopeEnd(); if (NormalDeactivateOrigIP.isSet()) NormalDeactivateOrigIP = Builder.saveAndClearIP(); diff --git a/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp b/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp index 3301178f32b49..cd9e823113967 100644 --- a/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp +++ b/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp @@ -95,7 +95,8 @@ int bar() // CHECK: invoke void @llvm.seh.try.begin() // CHECK: invoke.cont: // CHECK: invoke void @llvm.seh.scope.begin() -// CHECK: store volatile ptr %call, ptr %a, align 8 +// CHECK: invoke noundef ptr @"??0A@@QEAA@XZ" +// CHECK: invoke void @llvm.seh.scope.end() // CHECK: invoke void @llvm.seh.scope.begin() // CHECK: invoke void @"??1A@@QEAA@XZ" // CHECK: invoke void @llvm.seh.scope.end() >From 2b4e6f97230096dd1d2607f4b9f7e4b84451da5d Mon Sep 17 00:00:00 2001 From: GkvJwa <[email protected]> Date: Tue, 31 Mar 2026 21:38:40 +0800 Subject: [PATCH 3/6] 3 --- .../CodeGen/windows-seh-EHa-TryInFinally.cpp | 23 +++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp b/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp index cd9e823113967..e561c223919ed 100644 --- a/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp +++ b/clang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp @@ -91,25 +91,40 @@ int bar() } // CHECK-LABEL: @"?foo1@@YAXXZ"() + // CHECK-NOT: invoke void @llvm.seh.scope.begin() // CHECK: invoke void @llvm.seh.try.begin() -// CHECK: invoke.cont: +// CHECK: invoke.cont1: + // CHECK: invoke void @llvm.seh.scope.begin() // CHECK: invoke noundef ptr @"??0A@@QEAA@XZ" + // CHECK: invoke void @llvm.seh.scope.end() + // CHECK: invoke void @llvm.seh.scope.begin() // CHECK: invoke void @"??1A@@QEAA@XZ" + // CHECK: invoke void @llvm.seh.scope.end() -// CHECK-NOT: invoke void @llvm.seh.try.end() +// CHECK-NOT: @llvm.seh // CHECK: br label %delete.end + // CHECK: invoke void @llvm.seh.try.end() +// CHECK: invoke.cont15: + // CHECK: call void @"?fin$0@0@foo1@@"(i8 noundef 0 +// CHECK-NOT: @llvm.seh +// CHECK: ehcleanup: +// CHECK: invoke.cont7: // CHECK: cleanupret +// CHECK: invoke.cont14: +// CHECK: cleanupret + +// CHECK: ehcleanup16: // CHECK: call void @"?fin$0@0@foo1@@"(i8 noundef 1 -// CHECK-NOT: @llvm.seh.scope.end +// CHECK-NOT: @llvm.seh // CHECK: cleanupret struct A { - A(); + A() noexcept; ~A(); }; >From 68d73acd2346c9fc20fc1efaaca033938a2bc94b Mon Sep 17 00:00:00 2001 From: GkvJwa <[email protected]> Date: Tue, 31 Mar 2026 21:40:32 +0800 Subject: [PATCH 4/6] 4 --- clang/lib/CodeGen/CGExprCXX.cpp | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp index 82300c3ede183..296c0f838e88a 100644 --- a/clang/lib/CodeGen/CGExprCXX.cpp +++ b/clang/lib/CodeGen/CGExprCXX.cpp @@ -1720,6 +1720,18 @@ llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) { llvm::Instruction *cleanupDominator = nullptr; if (E->getOperatorDelete() && !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) { + // A potentially-throwing constructor inside __try requires C++ object + // unwinding, which is incompatible with SEH. + if (getLangOpts().CXXExceptions && currentFunctionUsesSEHTry()) { + if (const auto *ConstructExpr = E->getConstructExpr()) { + const auto *FPT = ConstructExpr->getConstructor() + ->getType() + ->castAs<FunctionProtoType>(); + if (!FPT->isNothrow()) + getContext().getDiagnostics().Report(E->getBeginLoc(), + diag::err_seh_object_unwinding); + } + } EnterNewDeleteCleanup(*this, E, TypeIdentityArg, allocation, allocSize, allocAlign, allocatorArgs); operatorDeleteCleanup = EHStack.stable_begin(); >From 9cbf298830cd6a8e700447bd3daa7880e7505b3e Mon Sep 17 00:00:00 2001 From: GkvJwa <[email protected]> Date: Tue, 31 Mar 2026 21:43:55 +0800 Subject: [PATCH 5/6] 5 --- clang/test/CodeGenCXX/exceptions-seh.cpp | 25 ++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/clang/test/CodeGenCXX/exceptions-seh.cpp b/clang/test/CodeGenCXX/exceptions-seh.cpp index 270b249f700fa..d385ed1e86728 100644 --- a/clang/test/CodeGenCXX/exceptions-seh.cpp +++ b/clang/test/CodeGenCXX/exceptions-seh.cpp @@ -12,6 +12,10 @@ // RUN: -fms-extensions -x c++ -emit-llvm-only -verify %s -DERR3 // RUN: %clang_cc1 -triple x86_64-windows -fcxx-exceptions -fexceptions \ // RUN: -fms-extensions -x c++ -emit-llvm-only -verify %s -DERR4 +// RUN: %clang_cc1 -triple x86_64-windows -fasync-exceptions -fcxx-exceptions -fexceptions \ +// RUN: -fms-extensions -x c++ -emit-llvm-only -verify %s -DERR_NEW_THROWING_CTOR +// RUN: %clang_cc1 -triple x86_64-windows -fasync-exceptions -fcxx-exceptions -fexceptions \ +// RUN: -fms-extensions -x c++ -emit-llvm-only -verify %s -DNOERR_NEW_NOEXCEPT_CTOR // RUN: %clang_cc1 -triple x86_64-windows \ // RUN: -fms-extensions -x c++ -emit-llvm-only -verify %s -DNOERR @@ -214,6 +218,27 @@ void seh_unwinding() { } __except (1) { } } +#elif defined(ERR_NEW_THROWING_CTOR) +void seh_unwinding() { + __try { + HasCleanup *p = new HasCleanup; // expected-error{{'__try' is not permitted in functions that require object unwinding}} + delete p; + } __except (1) { + } +} +#elif defined(NOERR_NEW_NOEXCEPT_CTOR) +// new-expression with a noexcept constructor should be fine. +struct NoThrowCtor { + NoThrowCtor() noexcept; + ~NoThrowCtor(); +}; +void seh_unwinding() { + __try { + NoThrowCtor *p = new NoThrowCtor; // expected-no-diagnostics + delete p; + } __except (1) { + } +} #elif defined(NOERR) void seh_unwinding() { __try { >From 25c7bf3313fb8982ca25ef546cc4acad8887e0c2 Mon Sep 17 00:00:00 2001 From: GkvJwa <[email protected]> Date: Tue, 31 Mar 2026 21:53:27 +0800 Subject: [PATCH 6/6] 6 --- clang/lib/CodeGen/CGCleanup.cpp | 7 +++---- clang/lib/CodeGen/CGExprCXX.cpp | 2 +- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/clang/lib/CodeGen/CGCleanup.cpp b/clang/lib/CodeGen/CGCleanup.cpp index b7130ff8578e1..0157ef4bdd5af 100644 --- a/clang/lib/CodeGen/CGCleanup.cpp +++ b/clang/lib/CodeGen/CGCleanup.cpp @@ -800,8 +800,7 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough, // block. if (NormalDeactivateOrigIP.isSet()) Builder.restoreIP(NormalDeactivateOrigIP); - if (Personality.isMSVCPersonality() && Builder.GetInsertBlock() && - !IsSEHFinallyCleanup) + if (Builder.GetInsertBlock() && !IsSEHFinallyCleanup) EmitSehCppScopeEnd(); if (NormalDeactivateOrigIP.isSet()) NormalDeactivateOrigIP = Builder.saveAndClearIP(); @@ -819,7 +818,7 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough, if (IsEHa && getInvokeDest()) { if (Scope.isSEHFinallyCleanup()) EmitSehTryScopeEnd(); - else if (Personality.isMSVCPersonality()) + else EmitSehCppScopeEnd(); } @@ -861,7 +860,7 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough, if (IsEHa && getInvokeDest()) { if (Scope.isSEHFinallyCleanup()) EmitSehTryScopeEnd(); - else if (Personality.isMSVCPersonality()) + else EmitSehCppScopeEnd(); } diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp index 296c0f838e88a..c585523f2718f 100644 --- a/clang/lib/CodeGen/CGExprCXX.cpp +++ b/clang/lib/CodeGen/CGExprCXX.cpp @@ -1729,7 +1729,7 @@ llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) { ->castAs<FunctionProtoType>(); if (!FPT->isNothrow()) getContext().getDiagnostics().Report(E->getBeginLoc(), - diag::err_seh_object_unwinding); + diag::err_seh_object_unwinding); } } EnterNewDeleteCleanup(*this, E, TypeIdentityArg, allocation, allocSize, _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
