https://gcc.gnu.org/g:f520f125920460d9360e2a5619b22c7ac81d35ba
commit r11-11494-gf520f125920460d9360e2a5619b22c7ac81d35ba
Author: Jakub Jelinek <ja...@redhat.com>
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 <ja...@redhat.com>
PR c++/113674
* attribs.c (extract_attribute_substring): Remove.
(lookup_scoped_attribute_spec): Don't call it.
* c-lex.c (c_common_has_attribute): Call canonicalize_attr_name.
* c-c++-common/Wattributes-3.c: New test.
(cherry picked from commit b42e978f29b33071addff6d7bb8bcdb11d176606)
Diff:
---
gcc/attribs.c | 15 ---------------
gcc/c-family/c-lex.c | 1 +
gcc/testsuite/c-c++-common/Wattributes-3.c | 13 +++++++++++++
3 files changed, 14 insertions(+), 15 deletions(-)
diff --git a/gcc/attribs.c b/gcc/attribs.c
index 47969bd77426..1dd0212448e4 100644
--- a/gcc/attribs.c
+++ b/gcc/attribs.c
@@ -105,20 +105,6 @@ 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)
-{
- if (str->length > 4 && str->str[0] == '_' && str->str[1] == '_'
- && str->str[str->length - 1] == '_' && str->str[str->length - 2] == '_')
- {
- str->length -= 4;
- str->str += 2;
- }
-}
-
/* Insert an array of attributes ATTRIBUTES into a namespace. This
array must be NULL terminated. NS is the name of attribute
namespace. The function returns the namespace into which the
@@ -312,7 +298,6 @@ 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/c-family/c-lex.c b/gcc/c-family/c-lex.c
index 6374b72ed2de..88ec7a48fcf1 100644
--- a/gcc/c-family/c-lex.c
+++ b/gcc/c-family/c-lex.c
@@ -338,6 +338,7 @@ c_common_has_attribute (cpp_reader *pfile, bool std_syntax)
tree attr_id
= get_identifier ((const char *)
cpp_token_as_text (pfile, nxt_token));
+ attr_id = canonicalize_attr_name (attr_id);
attr_name = build_tree_list (attr_ns, attr_id);
}
else
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 000000000000..a1a6d9a58955
--- /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;
+}
