https://github.com/DataCorrupted updated https://github.com/llvm/llvm-project/pull/178524
>From f57c297bc41117d67a5d89d06f78ac2b030b4de3 Mon Sep 17 00:00:00 2001 From: Peter Rong <[email protected]> Date: Thu, 22 Jan 2026 14:48:30 -0800 Subject: [PATCH 1/3] [clang] Fix sema clang can't handle objc lifetime correctly when casting add a test --- clang/lib/Sema/SemaInit.cpp | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp index ff278bc7471bd..117c2e4e6674d 100644 --- a/clang/lib/Sema/SemaInit.cpp +++ b/clang/lib/Sema/SemaInit.cpp @@ -5651,6 +5651,13 @@ static void TryReferenceInitializationCore(Sema &S, T1QualsIgnoreAS.removeAddressSpace(); T2QualsIgnoreAS.removeAddressSpace(); } + // Postpone ObjC lifetime conversions to after the temporary materialization + // conversion, similar to address space conversions. This handles cases like + // binding a __strong rvalue to a const __autoreleasing reference. + if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime()) { + T1QualsIgnoreAS.removeObjCLifetime(); + T2QualsIgnoreAS.removeObjCLifetime(); + } QualType cv1T4 = S.Context.getQualifiedType(cv2T2, T1QualsIgnoreAS); if (T1QualsIgnoreAS != T2QualsIgnoreAS) Sequence.AddQualificationConversionStep(cv1T4, ValueKind); @@ -5664,6 +5671,14 @@ static void TryReferenceInitializationCore(Sema &S, Sequence.AddQualificationConversionStep(cv1T4WithAS, ValueKind); cv1T4 = cv1T4WithAS; } + // Add ObjC lifetime conversion if required. + if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime()) { + auto T4Quals = cv1T4.getQualifiers(); + T4Quals.setObjCLifetime(T1Quals.getObjCLifetime()); + QualType cv1T4WithLifetime = S.Context.getQualifiedType(T2, T4Quals); + Sequence.AddQualificationConversionStep(cv1T4WithLifetime, ValueKind); + cv1T4 = cv1T4WithLifetime; + } // In any case, the reference is bound to the resulting glvalue (or to // an appropriate base class subobject). >From bea74c7aabe1bd5f2eba2567c374c6be3047bbcc Mon Sep 17 00:00:00 2001 From: Peter Rong <[email protected]> Date: Thu, 22 Jan 2026 14:48:30 -0800 Subject: [PATCH 2/3] Address reviewers --- clang/lib/Sema/SemaInit.cpp | 22 ++++++----- .../arc-lifetime-rvalue-ref-binding.mm | 39 +++++++++++++++++++ 2 files changed, 52 insertions(+), 9 deletions(-) create mode 100644 clang/test/SemaObjCXX/arc-lifetime-rvalue-ref-binding.mm diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp index 117c2e4e6674d..fad1a7775dc5c 100644 --- a/clang/lib/Sema/SemaInit.cpp +++ b/clang/lib/Sema/SemaInit.cpp @@ -5645,21 +5645,22 @@ static void TryReferenceInitializationCore(Sema &S, // applied. // Postpone address space conversions to after the temporary materialization // conversion to allow creating temporaries in the alloca address space. - auto T1QualsIgnoreAS = T1Quals; - auto T2QualsIgnoreAS = T2Quals; + auto T1QualsIgnoreConvertions = T1Quals; + auto T2QualsIgnoreConvertions = T2Quals; if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) { - T1QualsIgnoreAS.removeAddressSpace(); - T2QualsIgnoreAS.removeAddressSpace(); + T1QualsIgnoreConvertions.removeAddressSpace(); + T2QualsIgnoreConvertions.removeAddressSpace(); } // Postpone ObjC lifetime conversions to after the temporary materialization // conversion, similar to address space conversions. This handles cases like // binding a __strong rvalue to a const __autoreleasing reference. if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime()) { - T1QualsIgnoreAS.removeObjCLifetime(); - T2QualsIgnoreAS.removeObjCLifetime(); + T1QualsIgnoreConvertions.removeObjCLifetime(); + T2QualsIgnoreConvertions.removeObjCLifetime(); } - QualType cv1T4 = S.Context.getQualifiedType(cv2T2, T1QualsIgnoreAS); - if (T1QualsIgnoreAS != T2QualsIgnoreAS) + QualType cv1T4 = + S.Context.getQualifiedType(cv2T2, T1QualsIgnoreConvertions); + if (T1QualsIgnoreConvertions != T2QualsIgnoreConvertions) Sequence.AddQualificationConversionStep(cv1T4, ValueKind); Sequence.AddReferenceBindingStep(cv1T4, ValueKind == VK_PRValue); ValueKind = isLValueRef ? VK_LValue : VK_XValue; @@ -5675,7 +5676,10 @@ static void TryReferenceInitializationCore(Sema &S, if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime()) { auto T4Quals = cv1T4.getQualifiers(); T4Quals.setObjCLifetime(T1Quals.getObjCLifetime()); - QualType cv1T4WithLifetime = S.Context.getQualifiedType(T2, T4Quals); + // Apply T4Quals to the unqualified base type to avoid conflicting + // ObjC lifetime qualifiers in getQualifiedType. + QualType cv1T4WithLifetime = + S.Context.getQualifiedType(cv1T4.getUnqualifiedType(), T4Quals); Sequence.AddQualificationConversionStep(cv1T4WithLifetime, ValueKind); cv1T4 = cv1T4WithLifetime; } diff --git a/clang/test/SemaObjCXX/arc-lifetime-rvalue-ref-binding.mm b/clang/test/SemaObjCXX/arc-lifetime-rvalue-ref-binding.mm new file mode 100644 index 0000000000000..5db3f59f8fa08 --- /dev/null +++ b/clang/test/SemaObjCXX/arc-lifetime-rvalue-ref-binding.mm @@ -0,0 +1,39 @@ +// RUN: %clang_cc1 -std=c++17 -fsyntax-only -fobjc-arc -verify %s +// RUN: %clang_cc1 -std=c++17 -fobjc-arc -ast-dump %s 2>&1 | FileCheck %s +// expected-no-diagnostics + +// Test for binding ObjC ARC __strong rvalues to const __autoreleasing references. +// This previously caused an assertion failure in Qualifiers::addConsistentQualifiers +// when the compiler attempted to add conflicting ObjC lifetime qualifiers. + +// The const id& parameter has implicit __autoreleasing lifetime. +void take(const id&); + +// CHECK-LABEL: FunctionDecl {{.*}} test_rvalue_binding +// CHECK: CallExpr +// CHECK: ImplicitCastExpr {{.*}} 'const __autoreleasing id' lvalue <NoOp> +// CHECK-NEXT: CXXStaticCastExpr {{.*}} '__strong id' xvalue static_cast<__strong id &&> <NoOp> +void test_rvalue_binding() { + id obj = nullptr; + take(static_cast<id&&>(obj)); +} + +// CHECK-LABEL: FunctionDecl {{.*}} test_lvalue_binding +// CHECK: CallExpr +// CHECK: ImplicitCastExpr {{.*}} 'const __autoreleasing id' lvalue <NoOp> +// CHECK-NEXT: DeclRefExpr {{.*}} '__strong id' lvalue +void test_lvalue_binding() { + id obj = nullptr; + take(obj); +} + +// Test with fold expressions and perfect forwarding (original crash case). +template <typename... Args> +void call(Args... args) { + (take(static_cast<Args&&>(args)), ...); +} + +// CHECK-LABEL: FunctionDecl {{.*}} test_fold_expression +void test_fold_expression() { + call<id>(nullptr); +} >From 7260abe13189325120a1267f1c829bc52061bad8 Mon Sep 17 00:00:00 2001 From: Peter Rong <[email protected]> Date: Thu, 29 Jan 2026 08:57:26 -0800 Subject: [PATCH 3/3] add codegen test --- clang/docs/ReleaseNotes.rst | 4 +- .../arc-lifetime-rvalue-ref-binding.mm | 57 +++++++++++++++++++ 2 files changed, 60 insertions(+), 1 deletion(-) create mode 100644 clang/test/CodeGenObjCXX/arc-lifetime-rvalue-ref-binding.mm diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 42a300ca94581..c492c40ddbbba 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -236,6 +236,8 @@ Miscellaneous Clang Crashes Fixed - Fixed a crash when using loop hint with a value dependent argument inside a generic lambda. (#GH172289) - Fixed a crash in C++ overload resolution with ``_Atomic``-qualified argument types. (#GH170433) +- Fixed an assertion failure in ObjC++ ARC when binding a ``__strong`` rvalue reference to a ``const __autoreleasing`` reference. (#GH178524) + OpenACC Specific Changes ------------------------ @@ -317,7 +319,7 @@ AST Matchers clang-format ------------ -- Add ``ObjCSpaceAfterMethodDeclarationPrefix`` option to control space between the +- Add ``ObjCSpaceAfterMethodDeclarationPrefix`` option to control space between the '-'/'+' and the return type in Objective-C method declarations libclang diff --git a/clang/test/CodeGenObjCXX/arc-lifetime-rvalue-ref-binding.mm b/clang/test/CodeGenObjCXX/arc-lifetime-rvalue-ref-binding.mm new file mode 100644 index 0000000000000..03cc2762a9810 --- /dev/null +++ b/clang/test/CodeGenObjCXX/arc-lifetime-rvalue-ref-binding.mm @@ -0,0 +1,57 @@ +// RUN: %clang_cc1 -std=c++17 -triple x86_64-apple-darwin10 -emit-llvm -fobjc-arc -O0 -disable-llvm-passes -o - %s | FileCheck %s + +// Test for correct IR generation when binding ObjC ARC __strong rvalues +// to const __autoreleasing references. Previously, this caused an assertion +// failure in Qualifiers::addConsistentQualifiers. + +// The const id& parameter has implicit __autoreleasing lifetime. +void take(const id&); + +// CHECK-LABEL: define{{.*}} void @_Z19test_rvalue_bindingv() +// CHECK: [[OBJ:%.*]] = alloca ptr, align 8 +// CHECK: [[REF_TMP:%.*]] = alloca ptr, align 8 +// CHECK: store ptr null, ptr [[OBJ]], align 8 +// CHECK: [[LOAD:%.*]] = load ptr, ptr [[OBJ]], align 8 +// CHECK: [[RETAIN:%.*]] = call ptr @llvm.objc.retain(ptr [[LOAD]]) +// CHECK: store ptr [[RETAIN]], ptr [[REF_TMP]], align 8 +// CHECK: [[AUTORELEASE:%.*]] = call ptr @llvm.objc.autorelease(ptr [[RETAIN]]) +// CHECK: call void @_Z4takeRKU15__autoreleasingP11objc_object(ptr noundef nonnull align 8 dereferenceable(8) [[REF_TMP]]) +void test_rvalue_binding() { + id obj = nullptr; + take(static_cast<id&&>(obj)); +} + +// CHECK-LABEL: define{{.*}} void @_Z18test_lvalue_bindingv() +// CHECK: [[OBJ:%.*]] = alloca ptr, align 8 +// CHECK: [[REF_TMP:%.*]] = alloca ptr, align 8 +// CHECK: store ptr null, ptr [[OBJ]], align 8 +// CHECK: [[LOAD:%.*]] = load ptr, ptr [[OBJ]], align 8 +// CHECK: store ptr [[LOAD]], ptr [[REF_TMP]], align 8 +// CHECK: [[AUTORELEASE:%.*]] = call ptr @llvm.objc.autorelease(ptr [[LOAD]]) +// CHECK: call void @_Z4takeRKU15__autoreleasingP11objc_object(ptr noundef nonnull align 8 dereferenceable(8) [[REF_TMP]]) +void test_lvalue_binding() { + id obj = nullptr; + take(obj); +} + +// Test with fold expressions and perfect forwarding (original crash case). +template <typename... Args> +void call(Args... args) { + (take(static_cast<Args&&>(args)), ...); +} + +// CHECK-LABEL: define{{.*}} void @_Z20test_fold_expressionv() +// CHECK: call void @_Z4callIJP11objc_objectEEvDpT_(ptr noundef null) +void test_fold_expression() { + call<id>(nullptr); +} + +// CHECK-LABEL: define{{.*}} void @_Z4callIJP11objc_objectEEvDpT_(ptr noundef %args) +// CHECK: [[ARGS_ADDR:%.*]] = alloca ptr, align 8 +// CHECK: [[REF_TMP:%.*]] = alloca ptr, align 8 +// CHECK: store ptr %args, ptr [[ARGS_ADDR]], align 8 +// CHECK: [[LOAD:%.*]] = load ptr, ptr [[ARGS_ADDR]], align 8 +// CHECK: [[RETAIN:%.*]] = call ptr @llvm.objc.retain(ptr [[LOAD]]) +// CHECK: store ptr [[RETAIN]], ptr [[REF_TMP]], align 8 +// CHECK: [[AUTORELEASE:%.*]] = call ptr @llvm.objc.autorelease(ptr [[RETAIN]]) +// CHECK: call void @_Z4takeRKU15__autoreleasingP11objc_object(ptr noundef nonnull align 8 dereferenceable(8) [[REF_TMP]]) _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
