Author: Oleksandr Tarasiuk Date: 2026-05-06T20:08:48+03:00 New Revision: 3c3e7e0784befd7b80a7fe265a3e4eb7e7e12d2f
URL: https://github.com/llvm/llvm-project/commit/3c3e7e0784befd7b80a7fe265a3e4eb7e7e12d2f DIFF: https://github.com/llvm/llvm-project/commit/3c3e7e0784befd7b80a7fe265a3e4eb7e7e12d2f.diff LOG: [Clang] disallow selectany on non-global-variable declarations (#189641) Fixes #189141 --- This PR prevents a crash by disallowing the use of the `selectany` attribute in global variable declarations. Added: Modified: clang/docs/ReleaseNotes.rst clang/include/clang/Basic/Attr.td clang/include/clang/Basic/DiagnosticSemaKinds.td clang/lib/Sema/SemaDecl.cpp clang/test/Misc/pragma-attribute-supported-attributes-list.test clang/test/Sema/attr-selectany.c clang/test/SemaCXX/attr-selectany.cpp clang/test/SemaCXX/declspec-selectany.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index c92bd8dad11af..c2323b58a3e06 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -352,6 +352,7 @@ Attribute Changes in Clang usage. - Clang now allows GNU attributes between a member declarator and bit-field width. (#GH184954) +- Clang now disallows use of the ``selectany`` attribute on non-global-variable declarations. (#GH189141) Improvements to Clang's diagnostics ----------------------------------- diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td index 70b5773f95b08..ffa6a17f51362 100644 --- a/clang/include/clang/Basic/Attr.td +++ b/clang/include/clang/Basic/Attr.td @@ -4510,6 +4510,8 @@ def DLLImportStaticLocal : InheritableAttr, TargetSpecificAttr<TargetHasDLLImpor def SelectAny : InheritableAttr { let Spellings = [Declspec<"selectany">, GCC<"selectany">]; + let Subjects = SubjectList<[NonParmVar], ErrorDiag, + "variable declarations with external linkage">; let Documentation = [SelectAnyDocs]; let SimpleHandler = 1; } diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index e059260778631..6646b37262d92 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -3904,8 +3904,8 @@ def warn_cmse_nonsecure_union : Warning< InGroup<DiagGroup<"cmse-union-leak">>; def err_attribute_weak_static : Error< "weak declaration cannot have internal linkage">; -def err_attribute_selectany_non_extern_data : Error< - "'selectany' can only be applied to data items with external linkage">; +def err_attribute_selectany_non_extern_var : Error< + "'selectany' can only be applied to variables with external linkage">; def warn_attribute_hybrid_patchable_non_extern : Warning< "'hybrid_patchable' is ignored on functions without external linkage">, InGroup<IgnoredAttributes>; diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index eb5b6d65b4d58..be9654078940f 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/lib/Sema/SemaDecl.cpp @@ -3140,15 +3140,16 @@ static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) { --E; continue; } - } else if (isa<SelectAnyAttr>(NewAttribute) && - cast<VarDecl>(New)->isInline() && - !cast<VarDecl>(New)->isInlineSpecified()) { + } else if (isa<SelectAnyAttr>(NewAttribute)) { // Don't warn about applying selectany to implicitly inline variables. // Older compilers and language modes would require the use of selectany // to make such variables inline, and it would have no effect if we // honored it. - ++I; - continue; + if (const auto *VD = dyn_cast<VarDecl>(New); + VD && VD->isInline() && !VD->isInlineSpecified()) { + ++I; + continue; + } } else if (isa<OMPDeclareVariantAttr>(NewAttribute)) { // We allow to add OMP[Begin]DeclareVariantAttr to be added to // declarations after definitions. @@ -7119,15 +7120,16 @@ static void checkAliasAttr(Sema &S, NamedDecl &ND) { } static void checkSelectAnyAttr(Sema &S, NamedDecl &ND) { - // 'selectany' only applies to externally visible variable declarations. - // It does not apply to functions. - if (SelectAnyAttr *Attr = ND.getAttr<SelectAnyAttr>()) { - if (isa<FunctionDecl>(ND) || !ND.isExternallyVisible()) { - S.Diag(Attr->getLocation(), - diag::err_attribute_selectany_non_extern_data); - ND.dropAttr<SelectAnyAttr>(); - } - } + SelectAnyAttr *Attr = ND.getAttr<SelectAnyAttr>(); + if (!Attr) + return; + + if (const auto *VD = dyn_cast<VarDecl>(&ND); + VD && !VD->isStaticDataMember() && VD->isExternallyVisible()) + return; + + S.Diag(Attr->getLocation(), diag::err_attribute_selectany_non_extern_var); + ND.dropAttr<SelectAnyAttr>(); } static void checkHybridPatchableAttr(Sema &S, NamedDecl &ND) { diff --git a/clang/test/Misc/pragma-attribute-supported-attributes-list.test b/clang/test/Misc/pragma-attribute-supported-attributes-list.test index 03b9a77ec1814..a5f157c18c57d 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_not_is_parameter) // 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..d8a0baf4edc0b 100644 --- a/clang/test/Sema/attr-selectany.c +++ b/clang/test/Sema/attr-selectany.c @@ -8,4 +8,8 @@ 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 x3(void) { } // expected-error {{'selectany' attribute only applies to variable declarations with external linkage}} + +void t() { + __declspec(selectany) extern int i; +} diff --git a/clang/test/SemaCXX/attr-selectany.cpp b/clang/test/SemaCXX/attr-selectany.cpp index 4afcb8130a14c..70f40618af8f3 100644 --- a/clang/test/SemaCXX/attr-selectany.cpp +++ b/clang/test/SemaCXX/attr-selectany.cpp @@ -1,14 +1,14 @@ -// RUN: %clang_cc1 -triple x86_64-win32 -fms-compatibility -fms-extensions -fsyntax-only -verify -std=c++11 %s -// RUN: %clang_cc1 -triple x86_64-unknown-linux -fms-compatibility -fms-extensions -fsyntax-only -verify -std=c++11 %s -// RUN: %clang_cc1 -triple x86_64-win32-macho -fms-compatibility -fms-extensions -fsyntax-only -verify -std=c++11 %s +// RUN: %clang_cc1 -triple x86_64-win32 -fms-compatibility -fms-extensions -fsyntax-only -verify=expected -std=c++11 %s +// RUN: %clang_cc1 -triple x86_64-unknown-linux -fms-compatibility -fms-extensions -fsyntax-only -verify=expected -std=c++11 %s +// RUN: %clang_cc1 -triple x86_64-win32-macho -fms-compatibility -fms-extensions -fsyntax-only -verify=expected,win23-macho -std=c++11 %s // 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 variable declarations with external linkage}} __declspec(selectany) int x1 = 1; -const __declspec(selectany) int x2 = 2; // expected-error{{'selectany' can only be applied to data items with external linkage}} +const __declspec(selectany) int x2 = 2; // expected-error{{'selectany' can only be applied to variables with external linkage}} extern const __declspec(selectany) int x3 = 3; @@ -18,7 +18,7 @@ const __declspec(selectany) int x4 = 4; // MSDN says this is incorrect, but MSVC doesn't diagnose it. extern __declspec(selectany) int x5; -static __declspec(selectany) int x6 = 2; // expected-error{{'selectany' can only be applied to data items with external linkage}} +static __declspec(selectany) int x6 = 2; // expected-error{{'selectany' can only be applied to variables with external linkage}} // FIXME: MSVC accepts this and makes x7 externally visible and comdat, but keep // it as internal and not weak/linkonce. @@ -36,7 +36,7 @@ class X { __declspec(selectany) X x(1); namespace { class Internal {}; } -__declspec(selectany) auto x8 = Internal(); // expected-error {{'selectany' can only be applied to data items with external linkage}} +__declspec(selectany) auto x8 = Internal(); // expected-error {{'selectany' can only be applied to variables with external linkage}} // The D3D11 headers do something like this. MSVC doesn't error on this at @@ -53,3 +53,20 @@ 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 variable declarations with external linkage}} +__declspec(selectany) struct S1 s1; + +void t() { + __declspec(selectany) int a; // expected-error {{'selectany' can only be applied to variables with external linkage}} + __declspec(selectany) extern int b; + __declspec(selectany) static int c; // expected-error {{'selectany' can only be applied to variables with external linkage}} + __declspec(selectany) thread_local int d; // expected-error {{'selectany' can only be applied to variables with external linkage}} win23-macho-error {{thread-local storage is not supported for the current target}} +} + +struct S2 {}; +struct __declspec(selectany) S2 s2; // expected-error {{'selectany' attribute only applies to variable declarations with external linkage}} + +struct S3 { + __declspec(selectany) static int a; // expected-error {{'selectany' can only be applied to variables with external linkage}} +}; diff --git a/clang/test/SemaCXX/declspec-selectany.cpp b/clang/test/SemaCXX/declspec-selectany.cpp index 7e64a2924c99a..9e9c906caa008 100644 --- a/clang/test/SemaCXX/declspec-selectany.cpp +++ b/clang/test/SemaCXX/declspec-selectany.cpp @@ -3,7 +3,7 @@ // RUN: %clang_cc1 -std=c++14 %s -triple x86_64-scei-ps4 -fdeclspec -verify // MSVC emits this error too. -const int __declspec(selectany) test1 = 0; // expected-error {{'selectany' can only be applied to data items with external linkage}} +const int __declspec(selectany) test1 = 0; // expected-error {{'selectany' can only be applied to variables with external linkage}} extern const int test2; const int test2 = 42; // expected-note {{previous definition is here}} @@ -15,4 +15,4 @@ const int __declspec(selectany) test3 = 42; // Standard usage. struct Test4 { static constexpr int sdm = 0; }; -__declspec(selectany) constexpr int Test4::sdm; // no warning +__declspec(selectany) constexpr int Test4::sdm; // expected-error {{'selectany' can only be applied to variables with external linkage}} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
