Author: Akira Hatanaka Date: 2025-01-21T09:03:50-08:00 New Revision: 485c80e1188192a4bb2a8cbddccdca82a6e33b81
URL: https://github.com/llvm/llvm-project/commit/485c80e1188192a4bb2a8cbddccdca82a6e33b81 DIFF: https://github.com/llvm/llvm-project/commit/485c80e1188192a4bb2a8cbddccdca82a6e33b81.diff LOG: [PAC] Ignore noexcept on function type when computing discriminator of member function pointers (#109056) This fixes a bug where a member function pointer signed using a function type with noexcept as the discriminator was being authenticated using a function type without noexcept. Fixes https://github.com/llvm/llvm-project/issues/106487. Added: Modified: clang/lib/AST/ASTContext.cpp clang/test/CodeGenCXX/ptrauth-member-function-pointer.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp index 155dbcfcaeed31..a4ba9fd0553464 100644 --- a/clang/lib/AST/ASTContext.cpp +++ b/clang/lib/AST/ASTContext.cpp @@ -3503,6 +3503,34 @@ uint16_t ASTContext::getPointerAuthTypeDiscriminator(QualType T) { encodeTypeForFunctionPointerAuth(*this, Out, T); } else { T = T.getUnqualifiedType(); + // Calls to member function pointers don't need to worry about + // language interop or the laxness of the C type compatibility rules. + // We just mangle the member pointer type directly, which is + // implicitly much stricter about type matching. However, we do + // strip any top-level exception specification before this mangling. + // C++23 requires calls to work when the function type is convertible + // to the pointer type by a function pointer conversion, which can + // change the exception specification. This does not technically + // require the exception specification to not affect representation, + // because the function pointer conversion is still always a direct + // value conversion and therefore an opportunity to resign the + // pointer. (This is in contrast to e.g. qualification conversions, + // which can be applied in nested pointer positions, effectively + // requiring qualified and unqualified representations to match.) + // However, it is pragmatic to ignore exception specifications + // because it allows a certain amount of `noexcept` mismatching + // to not become a visible ODR problem. This also leaves some + // room for the committee to add laxness to function pointer + // conversions in future standards. + if (auto *MPT = T->getAs<MemberPointerType>()) + if (MPT->isMemberFunctionPointer()) { + QualType PointeeType = MPT->getPointeeType(); + if (PointeeType->castAs<FunctionProtoType>()->getExceptionSpecType() != + EST_None) { + QualType FT = getFunctionTypeWithExceptionSpec(PointeeType, EST_None); + T = getMemberPointerType(FT, MPT->getClass()); + } + } std::unique_ptr<MangleContext> MC(createMangleContext()); MC->mangleCanonicalTypeName(T, Out); } diff --git a/clang/test/CodeGenCXX/ptrauth-member-function-pointer.cpp b/clang/test/CodeGenCXX/ptrauth-member-function-pointer.cpp index 0a9ac3fa510f56..e9436f11b5106e 100644 --- a/clang/test/CodeGenCXX/ptrauth-member-function-pointer.cpp +++ b/clang/test/CodeGenCXX/ptrauth-member-function-pointer.cpp @@ -1,10 +1,12 @@ // RUN: %clang_cc1 -triple arm64-apple-ios -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -o - %s | FileCheck -check-prefixes=CHECK,NODEBUG,DARWIN %s +// RUN: %clang_cc1 -triple arm64-apple-ios -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++17 -O1 -disable-llvm-passes -o - %s | FileCheck -check-prefixes=CHECK,NODEBUG,DARWIN,CXX17 %s // RUN: %clang_cc1 -triple arm64-apple-ios -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -debug-info-kind=limited -o - %s | FileCheck -check-prefixes=CHECK,DARWIN %s // RUN: %clang_cc1 -triple arm64-apple-ios -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -stack-protector 1 -o - %s | FileCheck %s -check-prefix=STACK-PROT // RUN: %clang_cc1 -triple arm64-apple-ios -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -stack-protector 2 -o - %s | FileCheck %s -check-prefix=STACK-PROT // RUN: %clang_cc1 -triple arm64-apple-ios -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -stack-protector 3 -o - %s | FileCheck %s -check-prefix=STACK-PROT // RUN: %clang_cc1 -triple aarch64-linux-gnu -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -o - %s | FileCheck -check-prefixes=CHECK,NODEBUG,ELF %s +// RUN: %clang_cc1 -triple aarch64-linux-gnu -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++17 -O1 -disable-llvm-passes -o - %s | FileCheck -check-prefixes=CHECK,NODEBUG,ELF,CXX17 %s // RUN: %clang_cc1 -triple aarch64-linux-gnu -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -debug-info-kind=limited -o - %s | FileCheck -check-prefixes=CHECK,ELF %s // RUN: %clang_cc1 -triple aarch64-linux-gnu -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -stack-protector 1 -o - %s | FileCheck %s -check-prefix=STACK-PROT // RUN: %clang_cc1 -triple aarch64-linux-gnu -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -stack-protector 2 -o - %s | FileCheck %s -check-prefix=STACK-PROT @@ -20,6 +22,10 @@ // CHECK: @__const._Z13testArrayInitv.c0 = private unnamed_addr constant %struct.Class0 { { i64, i64 } { i64 ptrtoint (ptr ptrauth (ptr @_ZN5Base011nonvirtual0Ev, i32 0, i64 35591) to i64), i64 0 } }, align 8 // CHECK: @__const._Z13testArrayInitv.c1 = private unnamed_addr constant %struct.Class0 { { i64, i64 } { i64 ptrtoint (ptr ptrauth (ptr @_ZN5Base08virtual1Ev_vfpthunk_, i32 0, i64 35591) to i64), i64 0 } }, align 8 +// CHECK: @_ZN22testNoexceptConversion6mfptr1E = global { i64, i64 } { i64 ptrtoint (ptr ptrauth (ptr @_ZN22testNoexceptConversion1S19nonvirtual_noexceptEv, i32 0, i64 [[TYPEDISC3:.*]]) to i64), i64 0 }, +// CHECK: @_ZN22testNoexceptConversion6mfptr2E = global { i64, i64 } { i64 ptrtoint (ptr ptrauth (ptr @_ZN22testNoexceptConversion1S16virtual_noexceptEv_vfpthunk_, i32 0, i64 [[TYPEDISC3]]) to i64), i64 0 }, +// CHECK: @_ZN22testNoexceptConversion15mfptr3_noexceptE = global { i64, i64 } { i64 ptrtoint (ptr ptrauth (ptr @_ZN22testNoexceptConversion1S19nonvirtual_noexceptEv, i32 0, i64 [[TYPEDISC3]]) to i64), i64 0 }, + // CHECK: @_ZTV5Base0 = unnamed_addr constant { [5 x ptr] } { [5 x ptr] [ptr null, ptr @_ZTI5Base0, // CHECK-SAME: ptr ptrauth (ptr @_ZN5Base08virtual1Ev, i32 0, i64 55600, ptr getelementptr inbounds ({ [5 x ptr] }, ptr @_ZTV5Base0, i32 0, i32 0, i32 2)), // CHECK-SAME: ptr ptrauth (ptr @_ZN5Base08virtual3Ev, i32 0, i64 53007, ptr getelementptr inbounds ({ [5 x ptr] }, ptr @_ZTV5Base0, i32 0, i32 0, i32 3)), @@ -77,6 +83,9 @@ struct Derived1 : Base0, Base1 { }; typedef void (Base0::*MethodTy0)(); +#if __cplusplus >= 201703L +typedef void (Base0::*NoExceptMethodTy0)() noexcept; +#endif typedef void (Base0::*VariadicMethodTy0)(int, ...); typedef void (Derived0::*MethodTy1)(); @@ -293,6 +302,16 @@ void test1(Base0 *a0, MethodTy0 a1) { (a0->*a1)(); } +// CXX17: define{{.*}} void @_Z14test1_noexceptP5Base0MS_DoFvvE( +// CXX17: %[[V14:.*]] = phi ptr [ %{{.*}}, {{.*}} ], [ %{{.*}}, {{.*}} ] +// CXX17: %[[V15:.*]] = phi i64 [ 0, {{.*}} ], [ [[TYPEDISC0]], {{.*}} ] +// CXX17: call void %[[V14]](ptr noundef nonnull align {{[0-9]+}} dereferenceable(8) %{{.*}}) {{.*}}[ "ptrauth"(i32 0, i64 %[[V15]]) ] +#if __cplusplus >= 201703L +void test1_noexcept(Base0 *a0, NoExceptMethodTy0 a1) { + (a0->*a1)(); +} +#endif + // CHECK: define{{.*}} void @_Z15testConversion0M5Base0FvvEM8Derived0FvvE([2 x i64] %[[METHOD0_COERCE:.*]], [2 x i64] %[[METHOD1_COERCE:.*]]) // CHECK: %[[METHOD0:.*]] = alloca { i64, i64 }, align 8 // CHECK: %[[METHOD1:.*]] = alloca { i64, i64 }, align 8 @@ -438,3 +457,47 @@ void testArrayInit() { void testConvertNull() { VariadicMethodTy0 t = (VariadicMethodTy0)(MethodTy0{}); } + +namespace testNoexceptConversion { + +// CHECK-LABEL: define internal void @__cxx_global_var_init() +// CHECK: %[[V0:.*]] = load { i64, i64 }, ptr @_ZN22testNoexceptConversion15mfptr0_noexceptE, align 8 +// CHECK: store { i64, i64 } %[[V0]], ptr @_ZN22testNoexceptConversion6mfptr4E, align 8 + +// CHECK: define {{.*}}void @_ZN22testNoexceptConversion5test0Ev() +// CHECK: %[[P0:.*]] = alloca { i64, i64 }, align 8 +// CHECK: store { i64, i64 } { i64 ptrtoint (ptr ptrauth (ptr @_ZN22testNoexceptConversion1S19nonvirtual_noexceptEv, i32 0, i64 [[TYPEDISC3]]) to i64), i64 0 }, ptr %[[P0]], align 8, + +// CHECK: define {{.*}}void @_ZN22testNoexceptConversion5test1Ev() +// CHECK: %[[P0:.*]] = alloca { i64, i64 }, align 8 +// CHECK: store { i64, i64 } { i64 ptrtoint (ptr ptrauth (ptr @_ZN22testNoexceptConversion1S16virtual_noexceptEv_vfpthunk_, i32 0, i64 [[TYPEDISC3]]) to i64), i64 0 }, ptr %[[P0]], align 8, + +// CHECK: define {{.*}}void @_ZN22testNoexceptConversion5test2Ev() +// CHECK: %[[P0:.*]] = alloca { i64, i64 }, align 8 +// CHECK: %[[V0:.*]] = load { i64, i64 }, ptr @_ZN22testNoexceptConversion15mfptr0_noexceptE, align 8 +// CHECK: store { i64, i64 } %[[V0]], ptr %[[P0]], align 8, + +struct S { + void nonvirtual_noexcept() noexcept; + virtual void virtual_noexcept() noexcept; +}; + +void (S::*mfptr0_noexcept)() noexcept; +void (S::*mfptr1)() = &S::nonvirtual_noexcept; +void (S::*mfptr2)() = &S::virtual_noexcept; +void (S::*mfptr3_noexcept)() noexcept = &S::nonvirtual_noexcept; +void (S::*mfptr4)() = mfptr0_noexcept; + +void test0() { + void (S::*p0)() = &S::nonvirtual_noexcept; +} + +void test1() { + void (S::*p0)() = &S::virtual_noexcept; +} + +void test2() { + void (S::*p0)() = mfptr0_noexcept; +} + +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
