https://gcc.gnu.org/g:fda7a897d037ff1c59630f0a741eb20e68f45848
commit r12-10511-gfda7a897d037ff1c59630f0a741eb20e68f45848 Author: Jakub Jelinek <[email protected]> Date: Mon Feb 12 20:45:01 2024 +0100 attribs: Don't canonicalize lookup_scoped_attribute_spec argument [PR113674] The C and C++ FEs when parsing attributes already canonicalize them (i.e. if they start with __ and end with __ substrings, we remove those). lookup_attribute already verifies in gcc_assert that the first character of name is not an underscore, and even lookup_scoped_attribute_spec doesn't attempt to canonicalize the namespace it is passed. But for some historic reason it was canonicalizing the name argument, which misbehaves when an attribute starts with ____ and ends with ____. I believe it is just wrong to try to canonicalize lookup_scope_attribute_spec name attribute, it should have been canonicalized already, in other spots where it is called it is already canonicalized before. 2024-02-12 Jakub Jelinek <[email protected]> PR c++/113674 * attribs.cc (extract_attribute_substring): Remove. (lookup_scoped_attribute_spec): Don't call it. * c-c++-common/Wattributes-3.c: New test. (cherry picked from commit b42e978f29b33071addff6d7bb8bcdb11d176606) Diff: --- gcc/attribs.cc | 10 ---------- gcc/testsuite/c-c++-common/Wattributes-3.c | 13 +++++++++++++ 2 files changed, 13 insertions(+), 10 deletions(-) diff --git a/gcc/attribs.cc b/gcc/attribs.cc index 876277dd5b3..f73e00b6201 100644 --- a/gcc/attribs.cc +++ b/gcc/attribs.cc @@ -109,15 +109,6 @@ static const struct attribute_spec empty_attribute_table[] = { NULL, 0, 0, false, false, false, false, NULL, NULL } }; -/* Return base name of the attribute. Ie '__attr__' is turned into 'attr'. - To avoid need for copying, we simply return length of the string. */ - -static void -extract_attribute_substring (struct substring *str) -{ - canonicalize_attr_name (str->str, str->length); -} - /* Insert an array of attributes ATTRIBUTES into a namespace. This array must be NULL terminated. NS is the name of attribute namespace. IGNORED_P is true iff all unknown attributes in this @@ -409,7 +400,6 @@ lookup_scoped_attribute_spec (const_tree ns, const_tree name) attr.str = IDENTIFIER_POINTER (name); attr.length = IDENTIFIER_LENGTH (name); - extract_attribute_substring (&attr); return attrs->attribute_hash->find_with_hash (&attr, substring_hash (attr.str, attr.length)); diff --git a/gcc/testsuite/c-c++-common/Wattributes-3.c b/gcc/testsuite/c-c++-common/Wattributes-3.c new file mode 100644 index 00000000000..a1a6d9a5895 --- /dev/null +++ b/gcc/testsuite/c-c++-common/Wattributes-3.c @@ -0,0 +1,13 @@ +/* PR c++/113674 */ +/* { dg-do compile { target { c || c++11 } } } */ +/* { dg-options "" } */ + +[[____noreturn____]] int foo (int i) /* { dg-warning "'__noreturn__' attribute (directive )?ignored" } */ +{ + return i; +} + +[[____maybe_unused____]] int bar (int i) /* { dg-warning "'__maybe_unused__' attribute (directive )?ignored" } */ +{ + return i; +}
