https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90511
Bug ID: 90511
Summary: bogus attributes silently accepted before struct or
union
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
When the attribute keyword is just before struct and union the GCC front-end
silently accepts any attribute, valid or not:
$ cat x.c && gcc -O2 -S -Wall -Wextra -Wpedantic x.c
__attribute__ ((bogus)) struct A { int i; };
__attribute__ ((totally, bogus (with, "arguments"))) union U { int i; };
The C++ front-end issues warnings:
x.c:1:32: warning: attribute ignored in declaration of ‘struct A’
[-Wattributes]
1 | __attribute__ ((bogus)) struct A { int i; };
| ^
x.c:1:32: note: attribute for ‘struct A’ must follow the ‘struct’ keyword
x.c:2:60: warning: attribute ignored in declaration of ‘union U’ [-Wattributes]
2 | __attribute__ ((totally, bogus (with, "arguments"))) union U { int i;
};
| ^
x.c:2:60: note: attribute for ‘union U’ must follow the ‘union’ keyword
Clang does as well:
x.c:1:17: warning: attribute 'bogus' is ignored, place it after "struct" to
apply attribute to type declaration [-Wignored-attributes]
__attribute__ ((bogus)) struct A { int i; };
^
x.c:2:26: warning: attribute 'bogus' is ignored, place it after "union" to
apply
attribute to type declaration [-Wignored-attributes]
__attribute__ ((totally, bogus (with, "arguments"))) union U { int i; };
^
x.c:2:17: warning: attribute 'totally' is ignored, place it after "union" to
apply attribute to type declaration [-Wignored-attributes]
__attribute__ ((totally, bogus (with, "arguments"))) union U { int i; };
^
3 warnings generated.
