Comptime slice of undefined zero-sized array pointer causes compile error

[SpexGuy]

// repro.zig
comptime { const y = @as([*]void, undefined)[0..4]; }

<source>:1:45: error: out of bounds slice
comptime { const y = @as([*]void, undefined)[0..4]; }
                                            ^

@as([*]void, undefined) yields a defined instance of [*]void, since zero-sized values cannot be undefined. Since the stride is zero, a slice of this value is the same size as the value, so this is not out of bounds.

[mikdusan]

With latest compiler this returns a different error. Can we consider this issue fixed?

repro.zig

comptime {
    const y = @as([*]void, undefined)[0..4];
    _ = y;
}

$ uname -a
Linux archlinux 6.1.2-arch1-1 #1 SMP PREEMPT_DYNAMIC Sat, 31 Dec 2022 17:40:35 +0000 x86_64 GNU/Linux

$ zig version
0.11.0-dev.1247+87b223428

zig build-obj repro.zig
repro.zig:2:38: error: non-zero length slice of undefined pointer
    const y = @as([*]void, undefined)[0..4];
              ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~

[nektro]

this is a stage2 issue with it producing an error when end is comptime known. the following passes as intended

test {
    var x: usize = 4;
    const y = @as([*]void, undefined)[0..x];
    _ = y;
}

[nektro]

related: #6706

[Vexu]

That error is unrelated to zero-bit types and seems quite intentional (72ca2b2) though I'm unsure why it was added and whether it is still necessary.

[Vexu]

Errors correctly in master.