https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88817
Bug ID: 88817
Summary: Diagnostics improvement: Does not detect attempt to
use void expression in some cases.
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: anders.granlund.0 at gmail dot com
Target Milestone: ---
Test case (prog.c):
extern void v;
int main(void)
{
_Generic(v, default: 0);
}
Compilation command line:
gcc prog.c -Wall -Wextra -std=c11 -pedantic-errors
Observed behaviour:
No error messages outputed.
Possible improvement:
The program has undefined behaviour because it attempts to use the void
expression v (as the controlling expression of _Generic).
Since GCC detects attempts to use void expressions in other case it would be
good if it detected it in this case also.
