Windows Zig · compiler development

I have a problem I'm not sure how to resolve. I am trying to get all the zig tests passing on Windows, however there is a conflict where if I make the changes required for the zig tests to pass, then at least one or more cli rust tests fail. And if I makes the changes to fix the rust cli tests then the zig tests now break again.

Zig tests PASS Rust tests FAIL

If I add the condition on windows in crates\compiler\builtins\bitcode\src\libc.zig on line 12 like follows in addition to some other changes all the zig tests will PASS.

if (arch != .wasm32 and builtin.os.tag != .windows) {
    @export(memcpy, .{ .name = "memcpy", .linkage = .Strong });
}

However the cli breakout test will fail with I don't know the address of the memcpy function! this may cause segfaults

Zig tests FAIL Rust tests PASS

Reverting it back to the below will fix the cli rust tests, but now zig tests will fail.

if (arch != .wasm32) {
    @export(memcpy, .{ .name = "memcpy", .linkage = .Strong });
}

PS C:\Users\bosyl\Documents\GitHub\roc\crates\compiler\builtins\bitcode\src> zig test .\main.zig
lld-link: error: duplicate symbol: memcpy
>>> defined at C:\Users\bosyl\Documents\GitHub\roc\crates\compiler\builtins\bitcode\src\libc.zig:24
>>>            .\zig-cache\o\7a9d119939433d987663f08665e5df61\test.obj
>>> defined at c.lib(c.obj)
error: LLDReportedFailure

Brendan Hansknecht (Sep 10 2023 at 15:22):

Oh, interesting. We are trying to claim/overwrite the memcpy symbol. So fundamentally, we don't want the system memcpy dependency. We want instead to use a static definition of memcpy that we define.

Brendan Hansknecht (Sep 10 2023 at 15:23):

On windows when running zig test, we are pulling in both versions of memcpy and the are conflicting. Thus, the linker is complaining.

Brendan Hansknecht (Sep 10 2023 at 15:23):

So the correct solution is probably to tell zig not to link in the system memcpy when compiling tests.

Brendan Hansknecht (Sep 10 2023 at 15:24):

That probably requires us to tell zig not to link in libc at all on windows (which we shouldn't need, we want to statically link in all function of libc into the builtins just like we do with memcpy).

Stream: compiler development

Topic: Windows Zig

Luke Boswell (Sep 10 2023 at 07:47):

Zig tests PASS Rust tests FAIL

Zig tests FAIL Rust tests PASS

Brendan Hansknecht (Sep 10 2023 at 15:22):

Brendan Hansknecht (Sep 10 2023 at 15:23):

Brendan Hansknecht (Sep 10 2023 at 15:23):

Brendan Hansknecht (Sep 10 2023 at 15:24):

Luke Boswell (Sep 10 2023 at 19:26):

Brendan Hansknecht (Sep 12 2023 at 19:36):