https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86719
Bug ID: 86719
Summary: case label does not reduce to an integer constant
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: zhonghao at pku dot org.cn
Target Milestone: ---
The code sample is as follow:
int main(void)
{
const int nFOO = 1;
int nFoo = 0;
switch(nFoo){
case nFOO:
exit(1);
}
exit(0);
}
gcc rejects the code:
gcc code1.c
code1.c: In function 'main':
code1.c:7:2: error: case label does not reduce to an integer constant
case nFOO:
^~~~
code1.c:8:2: warning: implicit declaration of function 'exit'
[-Wimplicit-function-declaration]
exit(1);
^~~~
code1.c:8:2: warning: incompatible implicit declaration of built-in function
'exit'
code1.c:8:2: note: include '<stdlib.h>' or provide a declaration of 'exit'
code1.c:1:1:
+#include <stdlib.h>
int main(void)
code1.c:8:2:
exit(1);
^~~~
code1.c:10:2: warning: incompatible implicit declaration of built-in function
'exit'
exit(0);
^~~~
code1.c:10:2: note: include '<stdlib.h>' or provide a declaration of 'exit'
The code looks legal. clang accepts it
