1const std = @import("std");
 2const Step = std.Build.Step;
 3const LazyPath = std.Build.LazyPath;
 4const InstallDir = std.Build.InstallDir;
 5const InstallFile = @This();
 6const assert = std.debug.assert;
 7
 8pub const base_id: Step.Id = .install_file;
 9
10step: Step,
11source: LazyPath,
12dir: InstallDir,
13dest_rel_path: []const u8,
14
15pub fn create(
16    owner: *std.Build,
17    source: LazyPath,
18    dir: InstallDir,
19    dest_rel_path: []const u8,
20) *InstallFile {
21    assert(dest_rel_path.len != 0);
22    const install_file = owner.allocator.create(InstallFile) catch @panic("OOM");
23    install_file.* = .{
24        .step = Step.init(.{
25            .id = base_id,
26            .name = owner.fmt("install {s} to {s}", .{ source.getDisplayName(), dest_rel_path }),
27            .owner = owner,
28            .makeFn = make,
29        }),
30        .source = source.dupe(owner),
31        .dir = dir.dupe(owner),
32        .dest_rel_path = owner.dupePath(dest_rel_path),
33    };
34    source.addStepDependencies(&install_file.step);
35    return install_file;
36}
37
38fn make(step: *Step, options: Step.MakeOptions) !void {
39    _ = options;
40    const b = step.owner;
41    const install_file: *InstallFile = @fieldParentPtr("step", step);
42    try step.singleUnchangingWatchInput(install_file.source);
43
44    const full_dest_path = b.getInstallPath(install_file.dir, install_file.dest_rel_path);
45    const p = try step.installFile(install_file.source, full_dest_path);
46    step.result_cached = p == .fresh;
47}