[Bug c++/107360] ICE on sizeof(*f(x)) when f's (deduced) return type is a pointer to VLA

[izbyshev at ispras dot ru via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107360

--- Comment #2 from Alexey Izbyshev <izbyshev at ispras dot ru> ---
(In reply to Andrew Pinski from comment #1)
> Maybe this should be invalid code ...

Yes, I think it should be invalid. VLAs are not allowed in function return
types in C. VLAs in C++ are a GCC extension, but it's unclear to me why (and
how) GCC should allow them in return types, even when they don't depend on
function parameters.

Currently, GCC crashes even in the latter case, e.g.:

extern int n;

auto f() {
    int (*a)[n] = 0;
    return a;
}

int g() {
    return sizeof *f();
}