[Bug c/98945] New: gcc does not warn when assigning value of type int (*)() to variable of type int (*)(double)

[rogi at skylittlesystem dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98945

            Bug ID: 98945
           Summary: gcc does not warn when assigning value of type int
                    (*)() to variable of type int (*)(double)
           Product: gcc
           Version: 10.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rogi at skylittlesystem dot org
  Target Milestone: ---

gcc complains about assigning a value of type `int (*)()` to a variable of type
`int (*)(float)`, but not for a variable of type `int (*)(double)`, which I
thought to be a minor bug.

First observed on version 9.3.0, and also after updating 10.2.1, both give the
same result.

Here's a small test case:

```
$ gcc -O0 -Wall -o a.out -xc - <<EOF
int f()
{
        return 0;
}

int main()
{
        int (*p_float)(float f) = f;
        int (*p_double)(double d) = f;
        return 0;
}
EOF
<stdin>: In function 'main':
<stdin>:8:35: warning: initialization of 'int (*)(float)' from incompatible
pointer type 'int (*)()' [-Wincompatible-pointer-types]
<stdin>:9:15: warning: unused variable 'p_double' [-Wunused-variable]
<stdin>:8:15: warning: unused variable 'p_float' [-Wunused-variable]
```

thanks <3