https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105156
Bug ID: 105156
Summary: No diagnostic for `enum { toobig = UINT_MAX }`
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: Keith.S.Thompson at gmail dot com
Target Milestone: ---
Source file:
```
#include <limits.h>
enum { toobig = UINT_MAX };
```
gcc version 11.2.0 on Ubuntu 20.04.4, x86_64
INT_MAX is 2147483647
UINT_MAX is 4294967295
The C11 and C17 standards both have the following constraint in 6.7.2.2:
> The expression that defines the value of an enumeration constant shall
> be an integer constant expression that has a value representable as an int.
"gcc -std=c17 -pedantic-errors -c c.c" does not produce a diagnostic for the
above source file.
If I replace UINT_MAX by 4294967295 I get a correct diagnostic:
c.c:3:18: error: ISO C restricts enumerator values to range of ‘int’
[-Wpedantic]
3 | enum { toobig2 = 4294967295 };
|
"gcc -E" indicates that the macro UINT_MAX expands to (0x7fffffff * 2U + 1U)
