LibtoolStep.zig

//! A zig builder step that runs "libtool" against a list of libraries
//! in order to create a single combined static library.
const LibtoolStep = @This();

const std = @import("std");
const Step = std.build.Step;
const RunStep = std.build.RunStep;
const FileSource = std.build.FileSource;

pub const Options = struct {
    /// The name of this step.
    name: []const u8,

    /// The filename (not the path) of the file to create. This will
    /// be placed in a unique hashed directory. Use out_path to access.
    out_name: []const u8,

    /// Library files (.a) to combine.
    sources: []FileSource,
};

/// The step to depend on.
step: *Step,

/// The output file from the libtool run.
output: FileSource,

/// Run libtool against a list of library files to combine into a single
/// static library.
pub fn create(b: *std.Build, opts: Options) *LibtoolStep {
    const self = b.allocator.create(LibtoolStep) catch @panic("OOM");

    const run_step = RunStep.create(b, b.fmt("libtool {s}", .{opts.name}));
    run_step.addArgs(&.{ "libtool", "-static", "-o" });
    const output = run_step.addOutputFileArg(opts.out_name);
    for (opts.sources) |source| run_step.addFileSourceArg(source);

    self.* = .{
        .step = &run_step.step,
        .output = output,
    };

    return self;
}

LipoStep.zig

//! A zig builder step that runs "lipo" on two binaries to create
//! a universal binary.
const LipoStep = @This();

const std = @import("std");
const Step = std.build.Step;
const RunStep = std.build.RunStep;
const FileSource = std.build.FileSource;

pub const Options = struct {
    /// The name of the xcframework to create.
    name: []const u8,

    /// The filename (not the path) of the file to create.
    out_name: []const u8,

    /// Library file (dylib, a) to package.
    input_a: FileSource,
    input_b: FileSource,
};

step: *Step,

/// Resulting binary
output: FileSource,

pub fn create(b: *std.Build, opts: Options) *LipoStep {
    const self = b.allocator.create(LipoStep) catch @panic("OOM");

    const run_step = RunStep.create(b, b.fmt("lipo {s}", .{opts.name}));
    run_step.addArgs(&.{ "lipo", "-create", "-output" });
    const output = run_step.addOutputFileArg(opts.out_name);
    run_step.addFileSourceArg(opts.input_a);
    run_step.addFileSourceArg(opts.input_b);

    self.* = .{
        .step = &run_step.step,
        .output = output,
    };

    return self;
}

XCFrameworkStep.zig

//! A zig builder step that runs "swift build" in the context of
//! a Swift project managed with SwiftPM. This is primarily meant to build
//! executables currently since that is what we build.
const XCFrameworkStep = @This();

const std = @import("std");
const Step = std.build.Step;
const RunStep = std.build.RunStep;
const FileSource = std.build.FileSource;

pub const Options = struct {
    /// The name of the xcframework to create.
    name: []const u8,

    /// The path to write the framework
    out_path: []const u8,

    /// Library file (dylib, a) to package.
    library: std.build.FileSource,

    /// Path to a directory with the headers.
    headers: std.build.FileSource,
};

step: *Step,

pub fn create(b: *std.Build, opts: Options) *XCFrameworkStep {
    const self = b.allocator.create(XCFrameworkStep) catch @panic("OOM");

    // We have to delete the old xcframework first since we're writing
    // to a static path.
    const run_delete = run: {
        const run = RunStep.create(b, b.fmt("xcframework delete {s}", .{opts.name}));
        run.has_side_effects = true;
        run.addArgs(&.{ "rm", "-rf", opts.out_path });
        break :run run;
    };

    // Then we run xcodebuild to create the framework.
    const run_create = run: {
        const run = RunStep.create(b, b.fmt("xcframework {s}", .{opts.name}));
        run.has_side_effects = true;
        run.addArgs(&.{ "xcodebuild", "-create-xcframework" });
        run.addArg("-library");
        run.addFileSourceArg(opts.library);
        run.addArg("-headers");
        run.addFileSourceArg(opts.headers);
        run.addArg("-output");
        run.addArg(opts.out_path);
        break :run run;
    };
    run_create.step.dependOn(&run_delete.step);

    self.* = .{
        .step = &run_create.step,
    };

    return self;
}