[Bug middle-end/98900] misleading -Wuninitialized using a variable outside its lifetime with -O2

[msebor at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98900

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
GCC 12 issues -Wdangling-poinnter for this bug now at all optimization levels. 
It still issues -Wuninitialized at -O1 and above, but with the dangling pointer
warning I don't think it's a big deal.  It should of course still be possible
to suppress it.

$ cat pr98900.c && gcc -S -Wall pr98900.c
int g = 10;

int main()
{
    int* p = 0;
    {
        int x = 15;
        p = &x;
    }

    g = *p;

    return 0;
}
pr98900.c: In function ‘main’:
pr98900.c:11:9: warning: using dangling pointer ‘p’ to ‘x’
[-Wdangling-pointer=]
   11 |     g = *p;
      |         ^~
pr98900.c:7:13: note: ‘x’ declared here
    7 |         int x = 15;
      |             ^