zig/test/link/wasm/basic-features/build.zig

const std = @import("std");

pub fn build(b: *std.Build) void {
    // Library with explicitly set cpu features
    const lib = b.addSharedLibrary(.{
        .name = "lib",
        .root_source_file = .{ .path = "main.zig" },
        .optimize = b.standardOptimizeOption(.{}),
        .target = .{
            .cpu_arch = .wasm32,
            .cpu_model = .{ .explicit = &std.Target.wasm.cpu.mvp },
            .cpu_features_add = std.Target.wasm.featureSet(&.{.atomics}),
            .os_tag = .freestanding,
        },
    });
    lib.use_llvm = false;
    lib.use_lld = false;

    // Verify the result contains the features explicitly set on the target for the library.
    const check = lib.checkObject(.wasm);
    check.checkStart("name target_features");
    check.checkNext("features 1");
    check.checkNext("+ atomics");

    const test_step = b.step("test", "Run linker test");
    test_step.dependOn(&check.step);
}