https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99974
Bug ID: 99974
Summary: attributes not propagated across function
redeclarations at local scope
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
The C++ front end fails to merge the noreturn and warn_unused_result function
attributes from one declaration at function scope to another. This is unlike
the C front end which merges some but not others (see pr99972).
$ cat z.C && gcc -S -Wall z.C
int gnr ()
{
extern __attribute__ ((noreturn)) int fnr ();
fnr ();
} // no return, no warning (good)
int hnr ()
{
extern int fnr ();
fnr ();
} // bogus -Wreturn-type (bug)
void gwur ()
{
extern __attribute__ ((warn_unused_result)) int fwur ();
fwur (); // -Wunused-result (good)
}
void hwur ()
{
extern int fwur ();
fwur (); // missing -Wunused-result (bug)
}
z.C: In function ‘int hnr()’:
z.C:12:1: warning: no return statement in function returning non-void
[-Wreturn-type]
12 | } // bogus -Wreturn-type (bug)
| ^
z.C: In function ‘void gwur()’:
z.C:18:8: warning: ignoring return value of ‘int fwur()’ declared with
attribute ‘warn_unused_result’ [-Wunused-result]
18 | fwur (); // -Wunused-result (good)
| ~~~~~^~
