https://gcc.gnu.org/g:3b7e865779d03b4d29375a3c28dfaa2172eced4a
commit r16-5937-g3b7e865779d03b4d29375a3c28dfaa2172eced4a Author: Jakub Jelinek <[email protected]> Date: Sat Dec 6 11:07:18 2025 +0100 c++: is_late_template_attribute and tsubst_attribute fixes This has been discussed in the 1/9 Reflection thread, but doesn't depend on reglection in any way. cp_parser_std_attribute calls lookup_attribute_spec as: const attribute_spec *as = lookup_attribute_spec (TREE_PURPOSE (attribute)); so with TREE_LIST where TREE_VALUE is attribute name and TREE_PURPOSE attribute ns. Similarly c_parser_std_attribute. And for attribute_takes_identifier_p those do: else if (attr_ns == gnu_identifier && attribute_takes_identifier_p (attr_id)) and bool takes_identifier = (ns != NULL_TREE && strcmp (IDENTIFIER_POINTER (ns), "gnu") == 0 && attribute_takes_identifier_p (name)); when handling std attributes (for GNU attributes they just call those with the IDENTIFIER_NODE name. is_late_template_attribute and tsubst_attribute pass to these functions just get_attribute_name though, so handle attributes in all namespaces as GNU attributes only, which means that lookup_attribute_spec can return NULL or find a different attribute if it is not from gnu:: or say standard attribute mapped to gnu::, or attribute_takes_identifier_p can return true even for attributes for which it shouldn't. I thought about changing attribute_takes_identifier_p to take optionally TREE_LIST, but that would mean handling it in the target hooks too and they only care about GNU attributes right now, so given the above parser.cc/c-parser.cc snippets, the following patch just follow what they do. 2025-12-06 Jakub Jelinek <[email protected]> * decl2.cc (is_late_template_attribute): Call lookup_attribute_spec on TREE_PURPOSE (attr) rather than name. Only call attribute_takes_identifier_p if get_attribute_namespace (attr) is gnu_identifier. * pt.cc (tsubst_attribute): Only call attribute_takes_identifier_p if get_attribute_namespace (t) is gnu_identifier. Diff: --- gcc/cp/decl2.cc | 7 +++++-- gcc/cp/pt.cc | 3 ++- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc index 9e135af41b34..8ec9740c8a9e 100644 --- a/gcc/cp/decl2.cc +++ b/gcc/cp/decl2.cc @@ -1468,7 +1468,8 @@ is_late_template_attribute (tree attr, tree decl) { tree name = get_attribute_name (attr); tree args = TREE_VALUE (attr); - const struct attribute_spec *spec = lookup_attribute_spec (name); + const struct attribute_spec *spec + = lookup_attribute_spec (TREE_PURPOSE (attr)); tree arg; if (!spec) @@ -1512,7 +1513,9 @@ is_late_template_attribute (tree attr, tree decl) second and following arguments. Attributes like mode, format, cleanup and several target specific attributes aren't late just because they have an IDENTIFIER_NODE as first argument. */ - if (arg == args && attribute_takes_identifier_p (name) + if (arg == args + && get_attribute_namespace (attr) == gnu_identifier + && attribute_takes_identifier_p (name) && identifier_p (t)) continue; diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 7a019d33bda1..8498730b6e43 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -12386,7 +12386,8 @@ tsubst_attribute (tree t, tree *decl_p, tree args, pass it through tsubst. Attributes like mode, format, cleanup and several target specific attributes expect it unmodified. */ - else if (attribute_takes_identifier_p (get_attribute_name (t))) + else if (get_attribute_namespace (t) == gnu_identifier + && attribute_takes_identifier_p (get_attribute_name (t))) { tree chain = tsubst_expr (TREE_CHAIN (val), args, complain, in_decl);
