[Bug c/102996] New: No warning on use dereferencing of uninitialized point in an array

[eyalroz1 at gmx dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102996

            Bug ID: 102996
           Summary: No warning on use dereferencing of uninitialized point
                    in an array
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: eyalroz1 at gmx dot com
  Target Milestone: ---

Consider the following two functions:

void foo() {
    int *as[2];
    *(as[0])=1;
}

void bar() {
    int i = 0;
    int *as[2];
    for(i=0;i<1;i++)
    {
        *(as[i])=i;
    }
}


When compiling these with -Wall, we get warnings about the uninitialized use of
as in the first function, but not in the second one.

GodBolt: https://godbolt.org/z/Ta9fWYWs6
Inspired by this StackOverflow question:
https://stackoverflow.com/q/69764896/1593077