https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122721
Bug ID: 122721
Summary: Fold more aggressively in static_assert(3)
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: [email protected]
Target Milestone: ---
It would be good to be able to statically assert conditions that are known at
compile time, even if they involve run-time variables, when optimizations are
high enough.
The most obvious program is:
```
alx@devuan:~/tmp$ cat sa.c
int
main(int argc, char *[])
{
int n = argc;
static_assert(n == argc);
}
```
```
alx@devuan:~/tmp$ gcc sa.c -O3
sa.c: In function ‘main’:
sa.c:6:25: error: expression in static assertion is not constant
6 | static_assert(n == argc);
| ~~^~~~~~~
```
Here, the compiler should be able to verify that n==argc is true, so rejecting
this code is unnecessary.
