https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108194
Bug ID: 108194
Summary: GCC won't treat two compatible function types as
compatible if any of them (or both of them) is
declared _Noreturn
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: pskocik at gmail dot com
Target Milestone: ---
(same with __attribute((noreturn))) Example (https://godbolt.org/z/ePGd95sWz):
void FN_A(void);
void FN_B(void);
_Noreturn void NR_FN_A(void);
_Noreturn void NR_FN_B(void);
_Static_assert(_Generic((__typeof(*(FN_A))*){0}, __typeof(*(FN_B))*: 1), "");
//OK ✓
_Static_assert(_Generic((__typeof(*(NR_FN_A))*){0}, __typeof(*(NR_FN_B))*: 1),
""); //ERROR ✗
_Static_assert(_Generic((__typeof(*(FN_A))*){0}, __typeof(*(NR_FN_B))*: 1),
""); //ERROR ✗
As you can see from the Compiler Explorer link, clang accepts all three, which
is as it should be as per the standard, where _Noreturn is a function specifier
(https://port70.net/~nsz/c/c11/n1570.html#6.7.4), which means it shouldn't even
go into the type.
(Personally, I don't even mind it going into the type just as long as two
otherwise identical _Noreturn functio declarations are deemed as having the
same type).
Regards,
Petr Skocik
