Zig 0.17.0-dev (Split by item)

This is an example of documentation generated by ZigDoc, an alternative to Zig's built-in Auto Doc feature. See also examples in other modes/formats. The project being documented here (as the example) is the Zig library itself.

write

Serialize.write
pub fn write(b: *std.Build, wc: *Configuration.Wip, writer: *std.Io.Writer) !void

File

lib/std/Build/Serialize.zig:17

Code

pub fn write(b: *std.Build, wc: *Configuration.Wip, writer: *std.Io.Writer) !void {
    const graph = b.graph;
    const arena = graph.arena;
    const gpa = wc.gpa;

    var s: Serialize = .{ .wc = wc, .arena = arena };

    try wc.path_deps.ensureTotalCapacityPrecise(gpa, graph.configure_dependencies.items.len);
    for (
        graph.configure_dependencies.items,
        wc.path_deps.addManyAsSliceAssumeCapacity(graph.configure_dependencies.items.len),
    ) |src, *dest| {
        dest.* = .{
            .flags = .{
                .base = switch (src.lazy_path) {
                    .src_path, .dependency => .build_root,
                    .generated => unreachable,
                    .cwd_relative => .cwd,
                    .relative => |r| r.base,
                },
                .mode = src.mode,
            },
            .sub = switch (src.lazy_path) {
                .src_path => |sp| try wc.addString(sp.sub_path),
                .generated => unreachable,
                .cwd_relative => |sub_path| try wc.addString(sub_path),
                .dependency => |d| try wc.addString(d.sub_path),
                .relative => |r| try wc.addString(r.sub_path),
            },
            .pkg = switch (src.lazy_path) {
                .src_path => |sp| .init(try s.builderToPackage(sp.owner)),
                .generated => unreachable,
                .cwd_relative, .relative => .none,
                .dependency => |d| .init(try s.builderToPackage(d.dependency.builder)),
            },
        };
    }

    // Starting from all top-level steps in `b`, traverse the entire step graph
    // and add all step dependencies implied by module graphs.
    const top_level_steps = b.top_level_steps.values();
    try s.step_map.ensureUnusedCapacity(arena, top_level_steps.len);
    for (top_level_steps) |tls| {
        s.step_map.putAssumeCapacityNoClobber(&tls.step, {});
    }
    {
        while (wc.steps.items.len < s.step_map.count()) {
            const step = s.step_map.keys()[wc.steps.items.len];

            // Set up any implied dependencies for this step. It's important that we do this first, so
            // that the loop below discovers steps implied by the module graph.
            try createModuleDependenciesForStep(step);

            try s.step_map.ensureUnusedCapacity(arena, step.dependencies.items.len);
            for (step.dependencies.items) |other_step| {
                s.step_map.putAssumeCapacity(other_step, {});
            }

            // Add and then de-duplicate dependencies.
            const dep_steps = try arena.alloc(Configuration.Step.Index, step.dependencies.items.len);
            for (dep_steps, step.dependencies.items) |*dest, src|
                dest.* = @fromBackingInt(@intCast(s.step_map.getIndex(src).?));

            const deps: Configuration.Deps.Index = try wc.addDeduped(Configuration.Deps, .{
                .steps = .{ .slice = dep_steps },
            });

            try wc.steps.ensureTotalCapacity(gpa, s.step_map.entries.capacity);
            wc.steps.appendAssumeCapacity(.{
                .name = try wc.addString(step.name),
                .owner = try s.builderToPackage(step.owner),
                .deps = deps,
                .max_rss = .fromBytes(step.max_rss),
                .extended = @fromBackingInt(@intCast(switch (step.tag) {
                    .top_level => e: {
                        const top_level: *Step.TopLevel = @fieldParentPtr("step", step);
                        break :e try wc.addExtraErased(Configuration.Step.TopLevel, .{
                            .description = try wc.addString(top_level.description),
                        });
                    },
                    .compile => e: {
                        const c: *Step.Compile = @fieldParentPtr("step", step);
                        const installed_headers: []u32 = try arena.alloc(u32, c.installed_headers.items.len);
                        for (installed_headers, c.installed_headers.items) |*dst, src| switch (src) {
                            .file => |file| {
                                dst.* = try wc.addExtraErased(Configuration.Step.Compile.InstalledHeader.File, .{
                                    .source = try s.addLazyPath(file.source),
                                    .dest_sub_path = try wc.addString(file.dest_rel_path),
                                });
                            },
                            .directory => |directory| {
                                const include_extensions = directory.options.include_extensions orelse &.{};
                                dst.* = try wc.addExtraErased(Configuration.Step.Compile.InstalledHeader.Directory, .{
                                    .flags = .{
                                        .include_extensions = include_extensions.len != 0,
                                        .exclude_extensions = directory.options.exclude_extensions.len != 0,
                                    },
                                    .source = try s.addLazyPath(directory.source),
                                    .dest_sub_path = try wc.addString(directory.dest_rel_path),
                                    .exclude_extensions = .{ .slice = try s.initStringList(directory.options.exclude_extensions) },
                                    .include_extensions = .{ .slice = try s.initStringList(include_extensions) },
                                });
                            },
                        };

                        break :e try wc.addExtraErased(Configuration.Step.Compile, .{
                            .flags = .{
                                .filters_len = c.filters.len != 0,
                                .installed_headers_len = installed_headers.len != 0,
                                .force_undefined_symbols_len = c.force_undefined_symbols.entries.len != 0,

                                .verbose_link = c.verbose_link,
                                .verbose_cc = c.verbose_cc,
                                .rdynamic = c.rdynamic,
                                .import_memory = c.import_memory,
                                .export_memory = c.export_memory,
                                .import_symbols = c.import_symbols,
                                .import_table = c.import_table,
                                .export_table = c.export_table,
                                .shared_memory = c.shared_memory,
                                .link_eh_frame_hdr = c.link_eh_frame_hdr,
                                .link_emit_relocs = c.link_emit_relocs,
                                .link_function_sections = c.link_function_sections,
                                .link_data_sections = c.link_data_sections,
                                .linker_dynamicbase = c.linker_dynamicbase,
                                .link_z_notext = c.link_z_notext,
                                .link_z_relro = c.link_z_relro,
                                .link_z_lazy = c.link_z_lazy,
                                .link_z_defs = c.link_z_defs,
                                .headerpad_max_install_names = c.headerpad_max_install_names,
                                .dead_strip_dylibs = c.dead_strip_dylibs,
                                .force_load_objc = c.force_load_objc,
                                .discard_local_symbols = c.discard_local_symbols,
                                .mingw_unicode_entry_point = c.mingw_unicode_entry_point,
                            },
                            .flags2 = .{
                                .pie = .init(c.pie),
                                .formatted_panics = .init(c.formatted_panics),
                                .bundle_compiler_rt = .init(c.bundle_compiler_rt),
                                .bundle_ubsan_rt = .init(c.bundle_ubsan_rt),
                                .each_lib_rpath = .init(c.each_lib_rpath),
                                .link_gc_sections = .init(c.link_gc_sections),
                                .linker_allow_shlib_undefined = .init(c.linker_allow_shlib_undefined),
                                .linker_allow_undefined_version = .init(c.linker_allow_undefined_version),
                                .linker_enable_new_dtags = .init(c.linker_enable_new_dtags),
                                .dll_export_fns = .init(c.dll_export_fns),
                                .use_llvm = .init(c.use_llvm),
                                .use_lld = .init(c.use_lld),
                                .use_new_linker = .init(c.use_new_linker),
                                .allow_so_scripts = .init(c.allow_so_scripts),
                                .sanitize_coverage_trace_pc_guard = .init(c.sanitize_coverage_trace_pc_guard),
                                .linkage = .init(c.linkage),
                            },
                            .flags3 = .{
                                .is_linking_libc = c.is_linking_libc,
                                .is_linking_libcpp = c.is_linking_libcpp,
                                .version = c.version != null,
                                .compress_debug_sections = c.compress_debug_sections,
                                .initial_memory = c.initial_memory != null,
                                .max_memory = c.max_memory != null,
                                .kind = c.kind,
                                .global_base = c.global_base != null,
                                .test_runner = if (c.test_runner) |tr| switch (tr.mode) {
                                    .simple => .simple,
                                    .server => .server,
                                } else .default,
                                .wasi_exec_model = .init(c.wasi_exec_model),
                                .win32_manifest = c.win32_manifest != null,
                                .win32_module_definition = c.win32_module_definition != null,
                                .zig_lib_dir = c.zig_lib_dir != null,
                                .rc_includes = c.rc_includes,
                                .image_base = c.image_base != null,
                                .build_id = .init(c.build_id),
                                .entry = switch (c.entry) {
                                    .default => .default,
                                    .disabled => .disabled,
                                    .enabled => .enabled,
                                    .symbol_name => .symbol_name,
                                },
                                .lto = .init(c.lto),
                                .subsystem = .init(c.subsystem),
                            },
                            .flags4 = .{
                                .libc_file = c.libc_file != null,
                                .link_z_common_page_size = c.link_z_common_page_size != null,
                                .link_z_max_page_size = c.link_z_max_page_size != null,
                                .pagezero_size = c.pagezero_size != null,
                                .stack_size = c.stack_size != null,
                                .headerpad_size = c.headerpad_size != null,
                                .error_limit = c.error_limit != null,
                                .install_name = c.install_name != null,
                                .entitlements = c.entitlements != null,
                                .expect_errors = if (c.expect_errors) |x| switch (x) {
                                    .contains => .contains,
                                    .exact => .exact,
                                    .starts_with => .starts_with,
                                    .stderr_contains => .stderr_contains,
                                } else .none,
                                .linker_script = c.linker_script != null,
                                .version_script = c.version_script != null,
                                .emit_directory = c.emit_directory != .none,
                                .generated_docs = c.generated_docs != .none,
                                .generated_asm = c.generated_asm != .none,
                                .generated_bin = c.generated_bin != .none,
                                .generated_pdb = c.generated_pdb != .none,
                                .generated_implib = c.generated_implib != .none,
                                .generated_llvm_bc = c.generated_llvm_bc != .none,
                                .generated_llvm_ir = c.generated_llvm_ir != .none,
                                .generated_h = c.generated_h != .none,
                                .incremental = .init(c.incremental),
                            },
                            .root_module = try s.addModule(c.root_module),
                            .root_name = try wc.addString(c.name),
                            .linker_script = .{ .value = try s.addOptionalLazyPath(c.linker_script) },
                            .version_script = .{ .value = try s.addOptionalLazyPath(c.version_script) },
                            .zig_lib_dir = .{ .value = try s.addOptionalLazyPath(c.zig_lib_dir) },
                            .libc_file = .{ .value = try s.addOptionalLazyPath(c.libc_file) },
                            .win32_manifest = .{ .value = try s.addOptionalLazyPath(c.win32_manifest) },
                            .win32_module_definition = .{ .value = try s.addOptionalLazyPath(c.win32_module_definition) },
                            .entitlements = .{ .value = try s.addOptionalLazyPath(c.entitlements) },
                            .version = .{ .value = try s.addOptionalSemVer(c.version) },
                            .install_name = .{ .value = try s.addOptionalString(c.install_name) },
                            .initial_memory = .{ .value = c.initial_memory },
                            .max_memory = .{ .value = c.max_memory },
                            .global_base = .{ .value = c.global_base },
                            .image_base = .{ .value = c.image_base },
                            .link_z_common_page_size = .{ .value = c.link_z_common_page_size },
                            .link_z_max_page_size = .{ .value = c.link_z_max_page_size },
                            .pagezero_size = .{ .value = c.pagezero_size },
                            .stack_size = .{ .value = c.stack_size },
                            .headerpad_size = .{ .value = c.headerpad_size },
                            .error_limit = .{ .value = c.error_limit },
                            .entry = .{ .value = switch (c.entry) {
                                .symbol_name => |name| try wc.addString(name),
                                .default, .disabled, .enabled => null,
                            } },
                            .build_id = .{ .value = if (c.build_id) |id| switch (id) {
                                .hexstring => |*hexstring| try wc.addString(hexstring.toSlice()),
                                .none, .fast, .uuid, .sha1, .md5 => null,
                            } else null },
                            .filters = .{ .slice = try s.initStringList(c.filters) },
                            .installed_headers = .initErased(installed_headers),
                            .force_undefined_symbols = .{ .slice = try s.initStringList(c.force_undefined_symbols.keys()) },
                            .expect_errors = .{ .u = if (c.expect_errors) |x| switch (x) {
                                .contains => |slice| .{ .contains = try wc.addString(slice) },
                                .exact => |exact| .{ .exact = .{ .slice = try s.initStringList(exact) } },
                                .starts_with => |slice| .{ .starts_with = try wc.addString(slice) },
                                .stderr_contains => |slice| .{ .stderr_contains = try wc.addString(slice) },
                            } else .none },
                            .test_runner = .{ .u = if (c.test_runner) |tr| switch (tr.mode) {
                                .simple => .{ .simple = try s.addLazyPath(tr.path) },
                                .server => .{ .server = try s.addLazyPath(tr.path) },
                            } else .default },

                            .emit_directory = .{ .value = c.emit_directory.unwrap() },
                            .generated_docs = .{ .value = c.generated_docs.unwrap() },
                            .generated_asm = .{ .value = c.generated_asm.unwrap() },
                            .generated_bin = .{ .value = c.generated_bin.unwrap() },
                            .generated_pdb = .{ .value = c.generated_pdb.unwrap() },
                            .generated_implib = .{ .value = c.generated_implib.unwrap() },
                            .generated_llvm_bc = .{ .value = c.generated_llvm_bc.unwrap() },
                            .generated_llvm_ir = .{ .value = c.generated_llvm_ir.unwrap() },
                            .generated_h = .{ .value = c.generated_h.unwrap() },
                        });
                    },
                    .install_artifact => e: {
                        const ia: *Step.InstallArtifact = @fieldParentPtr("step", step);
                        break :e try wc.addExtraErased(Configuration.Step.InstallArtifact, .{
                            .flags = .{
                                .dylib_symlinks = ia.dylib_symlinks,
                                .bin_dir = ia.dest_dir != null,
                                .implib_dir = ia.implib_dir != null,
                                .pdb_dir = ia.pdb_dir != null,
                                .h_dir = ia.h_dir != null,
                                .bin_sub_path = ia.dest_sub_path != null,
                            },
                            .bin_dir = .{ .value = try addInstallDirDefaultNull(wc, ia.dest_dir) },
                            .implib_dir = .{ .value = try addInstallDirDefaultNull(wc, ia.implib_dir) },
                            .pdb_dir = .{ .value = try addInstallDirDefaultNull(wc, ia.pdb_dir) },
                            .h_dir = .{ .value = try addInstallDirDefaultNull(wc, ia.h_dir) },
                            .bin_sub_path = .{ .value = try s.addOptionalString(ia.dest_sub_path) },
                        });
                    },
                    .install_file => e: {
                        const sif: *Step.InstallFile = @fieldParentPtr("step", step);
                        break :e try wc.addExtraErased(Configuration.Step.InstallFile, .{
                            .source = try s.addLazyPath(sif.source),
                            .dest_dir = try addInstallDir(wc, sif.dir),
                            .dest_sub_path = try wc.addString(sif.dest_rel_path),
                        });
                    },
                    .install_dir => e: {
                        const sid: *Step.InstallDir = @fieldParentPtr("step", step);
                        const dest_sub_path: ?[]const u8 = if (sid.options.install_subdir.len != 0)
                            sid.options.install_subdir
                        else
                            null;
                        const include_extensions = sid.options.include_extensions orelse &.{};
                        break :e try wc.addExtraErased(Configuration.Step.InstallDir, .{
                            .flags = .{
                                .dest_sub_path = dest_sub_path != null,
                                .exclude_extensions = sid.options.exclude_extensions.len != 0,
                                .include_extensions = include_extensions.len != 0,
                                .include_extensions_active = sid.options.include_extensions != null,
                                .blank_extensions = sid.options.blank_extensions.len != 0,
                            },
                            .source_dir = try s.addLazyPath(sid.options.source_dir),
                            .dest_dir = try addInstallDir(wc, sid.options.install_dir),
                            .dest_sub_path = .{ .value = try s.addOptionalString(dest_sub_path) },
                            .exclude_extensions = .{ .slice = try s.initStringList(sid.options.exclude_extensions) },
                            .include_extensions = .{ .slice = try s.initStringList(include_extensions) },
                            .blank_extensions = .{ .slice = try s.initStringList(sid.options.blank_extensions) },
                        });
                    },
                    .fail => e: {
                        const sf: *Step.Fail = @fieldParentPtr("step", step);
                        break :e try wc.addExtraErased(Configuration.Step.Fail, .{
                            .msg = sf.error_msg,
                        });
                    },
                    .find_program => e: {
                        const fp: *Step.FindProgram = @fieldParentPtr("step", step);
                        break :e try wc.addExtraErased(Configuration.Step.FindProgram, .{
                            .names = fp.names,
                            .found_path = fp.found_path,
                        });
                    },
                    .fmt => e: {
                        const sf: *Step.Fmt = @fieldParentPtr("step", step);
                        break :e try wc.addExtraErased(Configuration.Step.Fmt, .{
                            .flags = .{
                                .paths = sf.paths.len != 0,
                                .exclude_paths = sf.exclude_paths.len != 0,
                                .check = sf.check,
                            },
                            .paths = .{ .slice = try s.initLazyPathList(sf.paths) },
                            .exclude_paths = .{ .slice = try s.initLazyPathList(sf.exclude_paths) },
                        });
                    },
                    .translate_c => e: {
                        const tc: *Step.TranslateC = @fieldParentPtr("step", step);

                        const system_libs = try arena.alloc(Configuration.SystemLib.Index, tc.system_libs.items.len);
                        for (system_libs, tc.system_libs.items) |*dest, *src| dest.* = try s.addSystemLib(src);

                        break :e try wc.addExtraErased(Configuration.Step.TranslateC, .{
                            .flags = .{
                                .include_dirs = tc.include_dirs.items.len != 0,
                                .system_libs = system_libs.len != 0,
                                .c_macros = tc.c_macros.items.len != 0,
                                .link_libc = tc.link_libc,
                                .optimize = .init(tc.optimize),
                            },
                            .src_path = try s.addLazyPath(tc.source),
                            .output_file = tc.output_file,
                            .include_dirs = .init(try s.initIncludeDirList(tc.include_dirs.items)),
                            .system_libs = .{ .slice = system_libs },
                            .c_macros = .{ .slice = tc.c_macros.items },
                            .target = try addOptionalResolvedTarget(wc, tc.target),
                        });
                    },
                    .write_file => e: {
                        const wf: *Step.WriteFile = @fieldParentPtr("step", step);

                        const directories = try arena.alloc(
                            Configuration.Step.WriteFile.Directory,
                            wf.directories.items.len,
                        );
                        for (directories, wf.directories.items) |*dest, src| dest.* = .{
                            .sub_path = src.sub_path,
                            .src_path = try s.addLazyPath(src.src_path),
                            .exclude_extensions = src.exclude_extensions,
                            .include_extensions = src.include_extensions,
                        };

                        break :e try wc.addExtraErased(Configuration.Step.WriteFile, .{
                            .flags = .{
                                .embeds = wf.embeds.items.len != 0,
                                .copies = wf.copies.items.len != 0,
                                .directories = directories.len != 0,
                                .mode = switch (wf.mode) {
                                    .whole_cached => .whole_cached,
                                    .tmp => .tmp,
                                    .mutate => .mutate,
                                },
                            },
                            .generated_directory = wf.generated_directory,
                            .embeds = .{ .slice = wf.embeds.items },
                            .copies = .{ .slice = try s.initCopyList(wf.copies.items) },
                            .directories = .{ .slice = directories },
                            .mutate_path = .{ .value = switch (wf.mode) {
                                .mutate => |lp| try s.addLazyPath(lp),
                                .whole_cached, .tmp => null,
                            } },
                        });
                    },
                    .update_source_files => e: {
                        const usf: *Step.UpdateSourceFiles = @fieldParentPtr("step", step);
                        break :e try wc.addExtraErased(Configuration.Step.UpdateSourceFiles, .{
                            .flags = .{
                                .embeds = usf.embeds.items.len != 0,
                                .copies = usf.copies.items.len != 0,
                            },
                            .embeds = .{ .slice = usf.embeds.items },
                            .copies = .{ .slice = try s.initCopyList(usf.copies.items) },
                        });
                    },
                    .run => e: {
                        const run: *Step.Run = @fieldParentPtr("step", step);
                        var expect_stderr_exact: ?Configuration.Bytes = null;
                        var expect_stdout_exact: ?Configuration.Bytes = null;
                        var expect_stderr_match: std.ArrayList(Configuration.Bytes) = .empty;
                        var expect_stdout_match: std.ArrayList(Configuration.Bytes) = .empty;
                        var expect_term: ?struct {
                            status: Configuration.Step.Run.ExpectTermStatus,
                            value: u32,
                        } = null;
                        var expect_stderr_snapshot: ?Configuration.LazyPath.Index = null;
                        var expect_stdout_snapshot: ?Configuration.LazyPath.Index = null;
                        switch (run.stdio) {
                            .check => |checks| for (checks.items) |check| switch (check) {
                                .expect_stderr_exact => |bytes| expect_stderr_exact = try wc.addBytes(bytes),
                                .expect_stdout_exact => |bytes| expect_stdout_exact = try wc.addBytes(bytes),
                                .expect_stderr_match => |bytes| {
                                    try expect_stderr_match.append(arena, try wc.addBytes(bytes));
                                },
                                .expect_stdout_match => |bytes| {
                                    try expect_stdout_match.append(arena, try wc.addBytes(bytes));
                                },
                                .expect_term => |t| expect_term = switch (t) {
                                    .exited => |x| .{ .status = .exited, .value = x },
                                    .signal => |x| .{ .status = .signal, .value = @backingInt(x) },
                                    .stopped => |x| .{ .status = .stopped, .value = @backingInt(x) },
                                    .unknown => |x| .{ .status = .unknown, .value = x },
                                },
                                .expect_stderr_snapshot => |path| expect_stderr_snapshot = try s.addLazyPath(path),
                                .expect_stdout_snapshot => |path| expect_stdout_snapshot = try s.addLazyPath(path),
                            },
                            else => {},
                        }

                        break :e try wc.addExtraErased(Configuration.Step.Run, .{
                            .flags = .{
                                .disable_zig_progress = run.disable_zig_progress,
                                .skip_foreign_checks = run.skip_foreign_checks,
                                .failing_to_execute_foreign_is_an_error = run.failing_to_execute_foreign_is_an_error,
                                .has_side_effects = run.has_side_effects,
                                .test_runner_mode = run.test_runner_mode,
                                .color = run.color,
                                .stdio = switch (run.stdio) {
                                    .infer_from_args => .infer_from_args,
                                    .inherit => .inherit,
                                    .check => .check,
                                    .zig_test => .zig_test,
                                },
                                .stdin = switch (run.stdin) {
                                    .none => .none,
                                    .bytes => .bytes,
                                    .lazy_path => .lazy_path,
                                },
                                .stdout_trim_whitespace = if (run.captured_stdout) |cs| cs.trim_whitespace else .none,
                                .stderr_trim_whitespace = if (run.captured_stderr) |cs| cs.trim_whitespace else .none,
                                .stdio_limit = run.stdio_limit != .unlimited,
                                .producer = run.producer != null,
                                .cwd = run.cwd != null,
                                .captured_stdout = run.captured_stdout != null,
                                .captured_stderr = run.captured_stderr != null,
                                .environ_map = run.environ_map != null,
                            },
                            .flags2 = .{
                                .expect_stderr_exact = expect_stderr_exact != null,
                                .expect_stdout_exact = expect_stdout_exact != null,
                                .expect_stderr_match = expect_stderr_match.items.len != 0,
                                .expect_stdout_match = expect_stdout_match.items.len != 0,
                                .expect_term = expect_term != null,
                                .expect_term_status = if (expect_term) |t| t.status else .exited,
                                .expect_stderr_snapshot = expect_stderr_snapshot != null,
                                .expect_stdout_snapshot = expect_stdout_snapshot != null,
                            },
                            .file_inputs = .{ .slice = try s.initLazyPathList(run.file_inputs.items) },
                            .args = .{ .slice = try s.initArgsList(run.argv.items) },
                            .cwd = .{ .value = try s.addOptionalLazyPath(run.cwd) },
                            .preopen_names = .{ .slice = try s.initStringList(run.preopens.keys()) },
                            .preopen_paths = .{ .slice = try s.initLazyPathList(run.preopens.values()) },
                            .captured_stdout = .{ .value = if (run.captured_stdout) |cs| .{
                                .basename = try wc.addString(cs.basename),
                                .generated_file = cs.generated_file,
                            } else null },
                            .captured_stderr = .{ .value = if (run.captured_stderr) |cs| .{
                                .basename = try wc.addString(cs.basename),
                                .generated_file = cs.generated_file,
                            } else null },
                            .environ_map = .{ .value = try s.addEnvironMap(run.environ_map) },
                            .expect_term_value = .{ .value = if (expect_term) |t| t.value else null },
                            .stdio_limit = .{ .value = run.stdio_limit.toInt64() },
                            .producer = .{ .value = if (run.producer) |cs| s.stepIndex(&cs.step) else null },
                            .expect_stderr_exact = .{ .value = if (expect_stderr_exact) |bytes| bytes else null },
                            .expect_stdout_exact = .{ .value = if (expect_stdout_exact) |bytes| bytes else null },
                            .expect_stderr_match = .{ .slice = expect_stderr_match.items },
                            .expect_stdout_match = .{ .slice = expect_stdout_match.items },
                            .expect_stderr_snapshot = .{ .value = expect_stderr_snapshot orelse null },
                            .expect_stdout_snapshot = .{ .value = expect_stdout_snapshot orelse null },
                            .stdin = .{ .u = switch (run.stdin) {
                                .none => .none,
                                .bytes => |bytes| .{ .bytes = try wc.addBytes(bytes) },
                                .lazy_path => |lp| .{ .lazy_path = try s.addLazyPath(lp) },
                            } },
                        });
                    },
                    .check_file => e: {
                        const cf: *Step.CheckFile = @fieldParentPtr("step", step);
                        break :e try wc.addExtraErased(Configuration.Step.CheckFile, .{
                            .flags = .{
                                .expected_exact = cf.expected_exact != null,
                                .expected_matches = cf.expected_matches.len != 0,
                                .max_bytes = cf.max_bytes != null,
                            },
                            .file = try s.addLazyPath(cf.file),
                            .expected_exact = .{ .value = cf.expected_exact },
                            .expected_matches = .{ .slice = cf.expected_matches },
                            .max_bytes = .{ .value = cf.max_bytes },
                        });
                    },
                    .config_header => e: {
                        const ch: *Step.ConfigHeader = @fieldParentPtr("step", step);
                        const lazy_path: ?std.Build.LazyPath = ch.style.getPath();
                        const pairs = try arena.alloc(Configuration.Step.ConfigHeader.Value.Pair, ch.values.count());
                        for (pairs, ch.values.keys(), ch.values.values()) |*pair, key, value| pair.* = .{
                            .key = try wc.addString(key),
                            .index = switch (value) {
                                .undef => .undef,
                                .defined => .defined,
                                .boolean => |x| switch (x) {
                                    false => .bool_false,
                                    true => .bool_true,
                                },
                                .int => |x| switch (x) {
                                    0 => .int_0,
                                    1 => .int_1,
                                    else => try wc.addExtra(Configuration.Step.ConfigHeader.Value, .initSigned(x)),
                                },
                                .ident => |x| try wc.addExtra(Configuration.Step.ConfigHeader.Value, .{
                                    .flags = .{
                                        .tag = .ident,
                                        .small = 0,
                                    },
                                    .i64 = .{ .value = null },
                                    .u64 = .{ .value = null },
                                    .ident = .{ .value = try wc.addString(x) },
                                    .string = .{ .value = null },
                                }),
                                .string => |x| try wc.addExtra(Configuration.Step.ConfigHeader.Value, .{
                                    .flags = .{
                                        .tag = .string,
                                        .small = 0,
                                    },
                                    .i64 = .{ .value = null },
                                    .u64 = .{ .value = null },
                                    .ident = .{ .value = null },
                                    .string = .{ .value = try wc.addString(x) },
                                }),
                            },
                        };
                        break :e try wc.addExtraErased(Configuration.Step.ConfigHeader, .{
                            .flags = .{
                                .template_file = lazy_path != null,
                                .style = .init(ch.style),
                                .input_size_limit = ch.input_size_limit != null,
                                .include_guard = ch.include_guard != .none,
                            },
                            .template_file = .{ .value = try s.addOptionalLazyPath(lazy_path) },
                            .generated_dir = ch.generated_dir,
                            .input_size_limit = .{ .value = ch.input_size_limit },
                            .include_path = try wc.addString(ch.include_path),
                            .include_guard = .{ .value = ch.include_guard.unwrap() },
                            .values = .{ .slice = pairs },
                        });
                    },
                    .obj_copy => e: {
                        const oc: *Step.ObjCopy = @fieldParentPtr("step", step);

                        const debug_basename: ?Configuration.String = if (oc.debug_file) |df|
                            df.basename.unwrap()
                        else
                            null;

                        const debug_file: ?Configuration.GeneratedFileIndex = if (oc.debug_file) |df|
                            df.output_file
                        else
                            null;

                        const add_sections = try arena.alloc(
                            Configuration.Step.ObjCopy.AddSection,
                            oc.add_sections.items.len,
                        );
                        for (add_sections, oc.add_sections.items) |*dest, src| dest.* = .{
                            .section_name = src.section_name,
                            .file_path = try s.addLazyPath(src.file_path),
                        };

                        break :e try wc.addExtraErased(Configuration.Step.ObjCopy, .{
                            .flags = .{
                                .basename = oc.basename != .none,
                                .debug_file = debug_file != null,
                                .debug_basename = debug_basename != null,
                                .format = .init(oc.format),
                                .strip = oc.strip,
                                .compress_debug = oc.compress_debug,
                                .only_section = oc.only_section != .none,
                                .pad_to = oc.pad_to != null,
                                .add_section = add_sections.len != 0,
                                .update_section = oc.update_sections.items.len != 0,
                            },
                            .input_file = try s.addLazyPath(oc.input_file),
                            .output_file = oc.output_file,
                            .basename = .{ .value = oc.basename.unwrap() },
                            .debug_file = .{ .value = debug_file },
                            .debug_basename = .{ .value = debug_basename },
                            .only_section = .{ .value = oc.only_section.unwrap() },
                            .pad_to = .{ .value = oc.pad_to },
                            .add_section = .{ .slice = add_sections },
                            .update_section = .{ .slice = oc.update_sections.items },
                        });
                    },
                    .options => e: {
                        const so: *Step.Options = @fieldParentPtr("step", step);

                        const args = try arena.alloc(Configuration.Step.Options.Arg, so.args.items.len);
                        for (args, so.args.items) |*dest, src| dest.* = .{
                            .name = src.name,
                            .path = try s.addLazyPath(src.path),
                        };

                        break :e try wc.addExtraErased(Configuration.Step.Options, .{
                            .flags = .{
                                .args = so.args.items.len != 0,
                            },
                            .generated_file = so.generated_file,
                            .contents = try wc.addBytes(so.contents.items),
                            .args = .{ .slice = args },
                        });
                    },
                })),
            });
        }
    }

    try wc.unlazy_deps.ensureUnusedCapacity(gpa, graph.needed_lazy_dependencies.keys().len);
    for (graph.needed_lazy_dependencies.keys()) |k| {
        wc.unlazy_deps.appendAssumeCapacity(try wc.addString(k));
    }

    try wc.write(writer, .{
        .default_step = s.stepIndex(b.default_step),
        .generated_files_len = @intCast(graph.generated_files.items.len),
        .poisoned = switch (graph.cache_poison) {
            .pure, .disallowed, .ignored => false,
            .poisoned => true,
        },
    });
}