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

const std = @import("std");

pub fn build(b: *std.Build) void {
    // Wasm Object file which we will use to infer the features from
    const c_obj = b.addObject(.{
        .name = "c_obj",
        .root_module = b.createModule(.{
            .root_source_file = null,
            .optimize = .Debug,
            .target = b.resolveTargetQuery(.{
                .cpu_arch = .wasm32,
                .cpu_model = .{ .explicit = &std.Target.wasm.cpu.bleeding_edge },
                .os_tag = .freestanding,
            }),
        }),
    });
    c_obj.root_module.addCSourceFile(.{ .file = b.path("foo.c"), .flags = &.{} });

    // Wasm library that doesn't have any features specified. This will
    // infer its featureset from other linked object files.
    const lib = b.addExecutable(.{
        .name = "lib",
        .root_module = b.createModule(.{
            .root_source_file = b.path("main.zig"),
            .optimize = .Debug,
            .target = b.resolveTargetQuery(.{
                .cpu_arch = .wasm32,
                .cpu_model = .{ .explicit = &std.Target.wasm.cpu.mvp },
                .os_tag = .freestanding,
            }),
        }),
    });
    lib.entry = .disabled;
    lib.use_llvm = false;
    lib.use_lld = false;
    lib.root_module.addObject(c_obj);

    lib.expect_errors = .{ .contains = "error: object requires atomics but specified target features exclude atomics" };
    _ = lib.getEmittedBin();

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