Get hello world compiling for iOS

[tanis2000]

I'm just figuring out at what point in time you are with iOS support for Zig. I tried to compile the basic project that you get when you initialize a new Zig project with the following command:

zig build-exe ./src/main.zig -target aarch64-ios

And I get the following error:

/usr/local/Cellar/zig/0.6.0_1/lib/zig/std/debug.zig:662:21: error: openSelfDebugInfo unsupported for this platform
            else => @compileError("openSelfDebugInfo unsupported for this platform"),
                    ^

Does that mean that iOS is not supported at all or is there anything I could do to help adding support for that platform?

[Sobeston]

Compiling a debug build (the default) has safety features enabled, and many of these things are OS specific. If you want to make good use of zig's runtime safety features, someone would have to implement these for IOS.

Large areas of the standard library as a whole likely won't be available yet.

For now, I think IOS will work in release fast and release small (providing you can avoid using a lot of the standard library).

[tanis2000]

Both release-fast and release-small seem to fail with the same error. Am I doing something wrong?

➜  test-zig zig build-exe ./src/main.zig -target aarch64-ios --release-fast
/usr/local/Cellar/zig/0.6.0_1/lib/zig/std/debug.zig:662:21: error: openSelfDebugInfo unsupported for this platform
            else => @compileError("openSelfDebugInfo unsupported for this platform"),
                    ^
➜  test-zig zig build-exe ./src/main.zig -target aarch64-ios --release-small
/usr/local/Cellar/zig/0.6.0_1/lib/zig/std/debug.zig:662:21: error: openSelfDebugInfo unsupported for this platform
            else => @compileError("openSelfDebugInfo unsupported for this platform"),
                    ^

[LemonBoy]

Am I doing something wrong?

The --release-* switches won't do anything for your problem. Try adding .ios in the switch where the @compilError is, I believe the Darwin codepath works just fine on IOS too.

[tanis2000]

So far my src/main.zig file (the only one I have besides the build.zig) is the following:

const std = @import("std");

pub fn main() anyerror!void {
    std.debug.warn("All your codebase are belong to us.\n", .{});
}

I even tried this because I thought std.debug could be the issue:

const std = @import("std");

pub fn main() anyerror!void {
    const stdout = std.io.getStdOut().outStream();
    try stdout.print("Hello, {}!\n", .{"world"});
}

but the error is still the same.
I don't get where I should add an .ios to a switch... which switch? :)

[daurnimator]

The --release-* switches won't do anything for your problem. Try adding .ios in the switch where the @compilError is, I believe the Darwin codepath works just fine on IOS too.

wait..... why is ios different to darwin? they're the same kernel

[tanis2000]

@daurnimator yes it is the same kernel. But if I add .ios to this switch in the std library (I believe this is the switch @LemonBoy was referring to) then it compiles:

/// TODO resources https://github.com/ziglang/zig/issues/4353
pub fn openSelfDebugInfo(allocator: *mem.Allocator) anyerror!DebugInfo {
    noasync {
        if (builtin.strip_debug_info)
            return error.MissingDebugInfo;
        if (@hasDecl(root, "os") and @hasDecl(root.os, "debug") and @hasDecl(root.os.debug, "openSelfDebugInfo")) {
            return root.os.debug.openSelfDebugInfo(allocator);
        }
        switch (builtin.os.tag) {
            .linux,
            .freebsd,
            .netbsd,
            .dragonfly,
            .macosx,
            .windows,
            .ios,
            => return DebugInfo.init(allocator),
            else => @compileError("openSelfDebugInfo unsupported for this platform"),
        }
    }
}

[LemonBoy]

I don't get where I should add an .ios to a switch... which switch? :)

The one above /usr/local/Cellar/zig/0.6.0_1/lib/zig/std/debug.zig:662. I'd suggest you to fetch a copy from git to avoid modifying the homebrew copy.

wait..... why is ios different to darwin? they're the same kernel

I forgot to put back the .ios, .watchos and friends when I refactored the debug stuff.

[tanis2000]

@LemonBoy hah! now that's clear :)

Ok, then I have one more question regarding compiling for iOS. Let's assume that:

• I have a C library that I wrote that I use to make games on all kind of platforms with.
• In that library I am including SDL2 and other libraries as source code and compile them all statically into my library to make sure that I'm using the same versions that I have written my code with.
• I believe that Zig has no clue about CMake files
• But Zig is using clang to compile C code, so I guess it should be able to understand Obj-C code, too

Would it be possible to provide to Zig a list of folders with the source code of SDL2 and the like and write a build.zig script that compiles all of them with the correct inclusion files and the correct switches for clang and also for the Obj-C files?

[prime31]

@tanis2000 you're prolly gonna need to dive into this, update SDL and add iOS to the build script: https://github.com/andrewrk/zig-sdl

[tanis2000]

@prime31 I already did all of that in my own repo without all the extra stuff of that SDL repo. But I still have issues compiling for macOS, not even iOS... Actually the compiler itself is crashing: #5188

[andrewrk]

Would it be possible to provide to Zig a list of folders with the source code of SDL2 and the like and write a build.zig script that compiles all of them with the correct inclusion files and the correct switches for clang and also for the Obj-C files?

Yes, and you can see a proof-of-concept here: https://github.com/andrewrk/zig-sdl