Hi! I've noticed we advertise __has_cpp_attribute (gnu::trivial_abi) and __has_attribute (gnu::trivial_abi). It is true we have gnu::trivial_abi in the tables, but solely to give errors on those when using the gnu:: scope and to suggest [[clang::trivial_abi]] or __attribute__((trivial_abi)).
Lightly tested so far, ok for trunk if it passes full bootstrap/regtest? 2026-07-08 Jakub Jelinek <[email protected]> PR c++/107187 * c-lex.cc (c_common_has_attribute): Don't advertise __has_cpp_attribute (gnu::trivial_abi) in C++. * g++.dg/cpp0x/attr-trivial_abi8.C: New test. --- gcc/c-family/c-lex.cc.jj 2026-04-28 08:54:25.377643162 +0200 +++ gcc/c-family/c-lex.cc 2026-07-08 18:47:10.790872988 +0200 @@ -403,6 +403,13 @@ c_common_has_attribute (cpp_reader *pfil result = 1; if (result) attr_name = NULL_TREE; + /* gnu::trivial_abi is in the attribute table just + to error on it and suggest using [[clang::trivial_abi]] + or __attribute__((trivial_abi)). Don't advertise it. */ + else if (c_dialect_cxx () + && is_attribute_p ("gnu", attr_ns) + && is_attribute_p ("trivial_abi", attr_id)) + attr_name = NULL_TREE; else attr_name = build_tree_list (attr_ns, attr_id); } --- gcc/testsuite/g++.dg/cpp0x/attr-trivial_abi8.C.jj 2026-07-08 18:49:01.145455196 +0200 +++ gcc/testsuite/g++.dg/cpp0x/attr-trivial_abi8.C 2026-07-08 18:49:23.583166926 +0200 @@ -0,0 +1,20 @@ +// { dg-do compile { target c++11 } } + +#if __has_cpp_attribute (clang::trivial_abi) != 1 +#error +#endif +#if __has_cpp_attribute (gnu::trivial_abi) != 0 +#error +#endif +#if __has_cpp_attribute (trivial_abi) != 1 +#error +#endif +#if __has_attribute (clang::trivial_abi) != 1 +#error +#endif +#if __has_attribute (gnu::trivial_abi) != 0 +#error +#endif +#if __has_attribute (trivial_abi) != 1 +#error +#endif Jakub
