https://github.com/a-tarasyuk created https://github.com/llvm/llvm-project/pull/189641
Fixes #189141 --- This PR prevents a crash by disallowing the use of the `selectany` attribute in global variable declarations. >From 0bf941754a1c9c7717215fd961007f0c1c147cb7 Mon Sep 17 00:00:00 2001 From: Oleksandr Tarasiuk <[email protected]> Date: Tue, 31 Mar 2026 15:00:28 +0300 Subject: [PATCH] [Clang] disallow selectany on non-global-variable declarations --- clang/docs/ReleaseNotes.rst | 2 ++ clang/include/clang/Basic/Attr.td | 1 + .../pragma-attribute-supported-attributes-list.test | 1 + clang/test/Sema/attr-selectany.c | 2 +- clang/test/SemaCXX/attr-selectany.cpp | 13 ++++++++++++- 5 files changed, 17 insertions(+), 2 deletions(-) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index bbbd3a34e01d6..b963a8cb5e324 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -252,6 +252,8 @@ Attribute Changes in Clang sound because any writer must hold all capabilities, so holding any one prevents concurrent writes. +- Clang now disallows use of the ``selectany`` attribute on non-global-variable declarations. (#GH189141) + Improvements to Clang's diagnostics ----------------------------------- - ``-Wunused-but-set-variable`` now diagnoses file-scope variables with diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td index 8d716bd05b6ab..01fa34188da84 100644 --- a/clang/include/clang/Basic/Attr.td +++ b/clang/include/clang/Basic/Attr.td @@ -4477,6 +4477,7 @@ def DLLImportStaticLocal : InheritableAttr, TargetSpecificAttr<TargetHasDLLImpor def SelectAny : InheritableAttr { let Spellings = [Declspec<"selectany">, GCC<"selectany">]; + let Subjects = SubjectList<[GlobalVar], ErrorDiag>; let Documentation = [SelectAnyDocs]; let SimpleHandler = 1; } diff --git a/clang/test/Misc/pragma-attribute-supported-attributes-list.test b/clang/test/Misc/pragma-attribute-supported-attributes-list.test index 03b9a77ec1814..2c91b57477b44 100644 --- a/clang/test/Misc/pragma-attribute-supported-attributes-list.test +++ b/clang/test/Misc/pragma-attribute-supported-attributes-list.test @@ -201,6 +201,7 @@ // CHECK-NEXT: SYCLSpecialClass (SubjectMatchRule_record) // CHECK-NEXT: ScopedLockable (SubjectMatchRule_record) // CHECK-NEXT: Section (SubjectMatchRule_function, SubjectMatchRule_variable_is_global, SubjectMatchRule_objc_method, SubjectMatchRule_objc_property) +// CHECK-NEXT: SelectAny (SubjectMatchRule_variable_is_global) // CHECK-NEXT: SetTypestate (SubjectMatchRule_function_is_member) // CHECK-NEXT: SpeculativeLoadHardening (SubjectMatchRule_function, SubjectMatchRule_objc_method) // CHECK-NEXT: StackProtectorIgnore (SubjectMatchRule_variable_is_local) diff --git a/clang/test/Sema/attr-selectany.c b/clang/test/Sema/attr-selectany.c index 1078695c26abc..dcb7376382c1a 100644 --- a/clang/test/Sema/attr-selectany.c +++ b/clang/test/Sema/attr-selectany.c @@ -8,4 +8,4 @@ extern __declspec(selectany) const int x1 = 1; // no warning, const means we nee // Should we really warn on this? extern __declspec(selectany) int x2 = 1; // expected-warning {{'extern' variable has an initializer}} -__declspec(selectany) void foo(void) { } // expected-error{{'selectany' can only be applied to data items with external linkage}} +__declspec(selectany) void foo(void) { } // expected-error{{'selectany' attribute only applies to global variables}} diff --git a/clang/test/SemaCXX/attr-selectany.cpp b/clang/test/SemaCXX/attr-selectany.cpp index 4afcb8130a14c..b6e9172028296 100644 --- a/clang/test/SemaCXX/attr-selectany.cpp +++ b/clang/test/SemaCXX/attr-selectany.cpp @@ -4,7 +4,7 @@ // MSVC produces similar diagnostics. -__declspec(selectany) void foo() { } // expected-error{{'selectany' can only be applied to data items with external linkage}} +__declspec(selectany) void foo() { } // expected-error{{'selectany' attribute only applies to global variables}} __declspec(selectany) int x1 = 1; @@ -53,3 +53,14 @@ extern const SomeStruct some_struct; // Without selectany, this should stay an error. const SomeStruct some_struct2; // expected-error {{default initialization of an object of const type 'const SomeStruct' without a user-provided default constructor}} + +struct __declspec(selectany) S1 {}; // expected-error {{'selectany' attribute only applies to global variables}} +__declspec(selectany) struct S1 s1; + +void t() { + __declspec(selectany) int x; // expected-error {{'selectany' attribute only applies to global variables}} + __declspec(selectany) extern int y; +} + +struct S2 {}; +struct __declspec(selectany) S2 s2; // expected-error {{'selectany' attribute only applies to global variables}} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
