build system: follow-up enhancements regarding LazyPath

* introduce LazyPath.cwd_relative variant and use it for --zig-lib-dir. closes #12685
* move overrideZigLibDir and setMainPkgPath to options fields set once
  and then never mutated.
* avoid introducing Build/util.zig
* use doc comments for deprecation notices so that they show up in
  generated documentation.
* introduce InstallArtifact.Options, accept it as a parameter to
  addInstallArtifact, and move override_dest_dir into it. Instead of
  configuring the installation via Compile step, configure the
  installation via the InstallArtifact step. In retrospect this is
  obvious.
* remove calls to pushInstalledFile in InstallArtifact. See #14943
* rewrite InstallArtifact to not incorrectly observe whether a Compile
  step has any generated outputs. InstallArtifact is meant to trigger
  output generation.
* fix child process evaluation code handling of `-fno-emit-bin`.
* don't store out_h_filename, out_ll_filename, etc., pointlessly. these
  are all just simple extensions appended to the root name.
* make emit_directory optional. It's possible to have nothing outputted,
  for example, if you're just type-checking.
* avoid passing -femit-foo/-fno-emit-foo when it is the default
* rename ConfigHeader.getTemplate to getOutput
* deprecate addOptionArtifact
* update the random number seed of Options step caching.
* avoid using `inline for` pointlessly
* avoid using `override_Dest_dir` pointlessly
* avoid emitting an executable pointlessly in test cases

Removes forceBuild and forceEmit. Let's consider these additions separately.
Nearly all of the usage sites were suspicious.

build.zig

@@ -45,7 +45,8 @@ pub fn build(b: *std.Build) !void {
     const docgen_cmd = b.addRunArtifact(docgen_exe);
     docgen_cmd.addArgs(&.{ "--zig", b.zig_exe });
     if (b.zig_lib_dir) |p| {
-        docgen_cmd.addArgs(&.{ "--zig-lib-dir", b.pathFromRoot(p) });
+        docgen_cmd.addArg("--zig-lib-dir");
+        docgen_cmd.addFileArg(p);
     }
     docgen_cmd.addFileArg(.{ .path = "doc/langref.html.in" });
     const langref_file = docgen_cmd.addOutputFileArg("langref.html");
@@ -57,8 +58,8 @@ pub fn build(b: *std.Build) !void {
     const autodoc_test = b.addTest(.{
         .root_source_file = .{ .path = "lib/std/std.zig" },
         .target = target,
+        .zig_lib_dir = .{ .path = "lib" },
     });
-    autodoc_test.overrideZigLibDir(.{ .path = "lib" });
     const install_std_docs = b.addInstallDirectory(.{
         .source_dir = autodoc_test.getEmittedDocs(),
         .install_dir = .prefix,
@@ -87,8 +88,8 @@ pub fn build(b: *std.Build) !void {
         .name = "check-case",
         .root_source_file = .{ .path = "test/src/Cases.zig" },
         .optimize = optimize,
+        .main_pkg_path = .{ .path = "." },
     });
-    check_case_exe.setMainPkgPath(.{ .path = "." });
     check_case_exe.stack_size = stack_size;
     check_case_exe.single_threaded = single_threaded;
 
@@ -203,7 +204,7 @@ pub fn build(b: *std.Build) !void {
     );
 
     if (!no_bin) {
-        const install_exe = b.addInstallArtifact(exe);
+        const install_exe = b.addInstallArtifact(exe, .{});
         if (flat) {
             install_exe.dest_dir = .prefix;
         }
@@ -357,8 +358,8 @@ pub fn build(b: *std.Build) !void {
         else
             &[_][]const u8{ "-DTRACY_ENABLE=1", "-fno-sanitize=undefined" };
 
-        exe.addIncludePath(.{ .path = tracy_path });
+        exe.addIncludePath(.{ .cwd_relative = tracy_path });
-        exe.addCSourceFile(.{ .file = .{ .path = client_cpp }, .flags = tracy_c_flags });
+        exe.addCSourceFile(.{ .file = .{ .cwd_relative = client_cpp }, .flags = tracy_c_flags });
         if (!enable_llvm) {
             exe.linkSystemLibraryName("c++");
         }
@@ -597,7 +598,7 @@ fn addCmakeCfgOptionsToExe(
         // useful for package maintainers
         exe.headerpad_max_install_names = true;
     }
-    exe.addObjectFile(.{ .path = b.pathJoin(&[_][]const u8{
+    exe.addObjectFile(.{ .cwd_relative = b.pathJoin(&[_][]const u8{
         cfg.cmake_binary_dir,
         "zigcpp",
         b.fmt("{s}{s}{s}", .{
@@ -607,9 +608,9 @@ fn addCmakeCfgOptionsToExe(
         }),
     }) });
     assert(cfg.lld_include_dir.len != 0);
-    exe.addIncludePath(.{ .path = cfg.lld_include_dir });
+    exe.addIncludePath(.{ .cwd_relative = cfg.lld_include_dir });
-    exe.addIncludePath(.{ .path = cfg.llvm_include_dir });
+    exe.addIncludePath(.{ .cwd_relative = cfg.llvm_include_dir });
-    exe.addLibraryPath(.{ .path = cfg.llvm_lib_dir });
+    exe.addLibraryPath(.{ .cwd_relative = cfg.llvm_lib_dir });
     addCMakeLibraryList(exe, cfg.clang_libraries);
     addCMakeLibraryList(exe, cfg.lld_libraries);
     addCMakeLibraryList(exe, cfg.llvm_libraries);
@@ -665,7 +666,7 @@ fn addCmakeCfgOptionsToExe(
     }
 
     if (cfg.dia_guids_lib.len != 0) {
-        exe.addObjectFile(.{ .path = cfg.dia_guids_lib });
+        exe.addObjectFile(.{ .cwd_relative = cfg.dia_guids_lib });
     }
 }
 
@@ -726,7 +727,7 @@ fn addCxxKnownPath(
         }
         return error.RequiredLibraryNotFound;
     }
-    exe.addObjectFile(.{ .path = path_unpadded });
+    exe.addObjectFile(.{ .cwd_relative = path_unpadded });
 
     // TODO a way to integrate with system c++ include files here
     // c++ -E -Wp,-v -xc++ /dev/null
@@ -746,7 +747,7 @@ fn addCMakeLibraryList(exe: *std.Build.Step.Compile, list: []const u8) void {
         } else if (exe.target.isWindows() and mem.endsWith(u8, lib, ".lib") and !fs.path.isAbsolute(lib)) {
             exe.linkSystemLibrary(lib[0 .. lib.len - ".lib".len]);
         } else {
-            exe.addObjectFile(.{ .path = lib });
+            exe.addObjectFile(.{ .cwd_relative = lib });
         }
     }
 }

lib/build_runner.zig

@@ -188,10 +188,10 @@ pub fn main() !void {
                     usageAndErr(builder, false, stderr_stream);
                 };
             } else if (mem.eql(u8, arg, "--zig-lib-dir")) {
-                builder.zig_lib_dir = nextArg(args, &arg_idx) orelse {
+                builder.zig_lib_dir = .{ .cwd_relative = nextArg(args, &arg_idx) orelse {
                     std.debug.print("Expected argument after {s}\n\n", .{arg});
                     usageAndErr(builder, false, stderr_stream);
-                };
+                } };
             } else if (mem.eql(u8, arg, "--debug-log")) {
                 const next_arg = nextArg(args, &arg_idx) orelse {
                     std.debug.print("Expected argument after {s}\n\n", .{arg});

lib/std/Build.zig

@@ -19,8 +19,6 @@ const NativeTargetInfo = std.zig.system.NativeTargetInfo;
 const Sha256 = std.crypto.hash.sha2.Sha256;
 const Build = @This();
 
-const build_util = @import("Build/util.zig");
-
 pub const Cache = @import("Build/Cache.zig");
 
 /// deprecated: use `Step.Compile`.
@@ -59,6 +57,8 @@ pub const RunStep = @import("Build/Step/Run.zig");
 pub const TranslateCStep = @import("Build/Step/TranslateC.zig");
 /// deprecated: use `Step.WriteFile`.
 pub const WriteFileStep = @import("Build/Step/WriteFile.zig");
+/// deprecated: use `LazyPath`.
+pub const FileSource = LazyPath;
 
 install_tls: TopLevelStep,
 uninstall_tls: TopLevelStep,
@@ -95,8 +95,7 @@ build_root: Cache.Directory,
 cache_root: Cache.Directory,
 global_cache_root: Cache.Directory,
 cache: *Cache,
-/// If non-null, overrides the default zig lib dir.
+zig_lib_dir: ?LazyPath,
-zig_lib_dir: ?[]const u8,
 vcpkg_root: VcpkgRoot = .unattempted,
 pkg_config_pkg_list: ?(PkgConfigError![]const PkgConfigPkg) = null,
 args: ?[][]const u8 = null,
@@ -483,6 +482,8 @@ pub const ExecutableOptions = struct {
     single_threaded: ?bool = null,
     use_llvm: ?bool = null,
     use_lld: ?bool = null,
+    zig_lib_dir: ?LazyPath = null,
+    main_pkg_path: ?LazyPath = null,
 };
 
 pub fn addExecutable(b: *Build, options: ExecutableOptions) *Step.Compile {
@@ -499,6 +500,8 @@ pub fn addExecutable(b: *Build, options: ExecutableOptions) *Step.Compile {
         .single_threaded = options.single_threaded,
         .use_llvm = options.use_llvm,
         .use_lld = options.use_lld,
+        .zig_lib_dir = options.zig_lib_dir orelse b.zig_lib_dir,
+        .main_pkg_path = options.main_pkg_path,
     });
 }
 
@@ -512,6 +515,8 @@ pub const ObjectOptions = struct {
     single_threaded: ?bool = null,
     use_llvm: ?bool = null,
     use_lld: ?bool = null,
+    zig_lib_dir: ?LazyPath = null,
+    main_pkg_path: ?LazyPath = null,
 };
 
 pub fn addObject(b: *Build, options: ObjectOptions) *Step.Compile {
@@ -526,6 +531,8 @@ pub fn addObject(b: *Build, options: ObjectOptions) *Step.Compile {
         .single_threaded = options.single_threaded,
         .use_llvm = options.use_llvm,
         .use_lld = options.use_lld,
+        .zig_lib_dir = options.zig_lib_dir orelse b.zig_lib_dir,
+        .main_pkg_path = options.main_pkg_path,
     });
 }
 
@@ -540,6 +547,8 @@ pub const SharedLibraryOptions = struct {
     single_threaded: ?bool = null,
     use_llvm: ?bool = null,
     use_lld: ?bool = null,
+    zig_lib_dir: ?LazyPath = null,
+    main_pkg_path: ?LazyPath = null,
 };
 
 pub fn addSharedLibrary(b: *Build, options: SharedLibraryOptions) *Step.Compile {
@@ -556,6 +565,8 @@ pub fn addSharedLibrary(b: *Build, options: SharedLibraryOptions) *Step.Compile
         .single_threaded = options.single_threaded,
         .use_llvm = options.use_llvm,
         .use_lld = options.use_lld,
+        .zig_lib_dir = options.zig_lib_dir orelse b.zig_lib_dir,
+        .main_pkg_path = options.main_pkg_path,
     });
 }
 
@@ -570,6 +581,8 @@ pub const StaticLibraryOptions = struct {
     single_threaded: ?bool = null,
     use_llvm: ?bool = null,
     use_lld: ?bool = null,
+    zig_lib_dir: ?LazyPath = null,
+    main_pkg_path: ?LazyPath = null,
 };
 
 pub fn addStaticLibrary(b: *Build, options: StaticLibraryOptions) *Step.Compile {
@@ -586,6 +599,8 @@ pub fn addStaticLibrary(b: *Build, options: StaticLibraryOptions) *Step.Compile
         .single_threaded = options.single_threaded,
         .use_llvm = options.use_llvm,
         .use_lld = options.use_lld,
+        .zig_lib_dir = options.zig_lib_dir orelse b.zig_lib_dir,
+        .main_pkg_path = options.main_pkg_path,
     });
 }
 
@@ -602,6 +617,8 @@ pub const TestOptions = struct {
     single_threaded: ?bool = null,
     use_llvm: ?bool = null,
     use_lld: ?bool = null,
+    zig_lib_dir: ?LazyPath = null,
+    main_pkg_path: ?LazyPath = null,
 };
 
 pub fn addTest(b: *Build, options: TestOptions) *Step.Compile {
@@ -618,6 +635,8 @@ pub fn addTest(b: *Build, options: TestOptions) *Step.Compile {
         .single_threaded = options.single_threaded,
         .use_llvm = options.use_llvm,
         .use_lld = options.use_lld,
+        .zig_lib_dir = options.zig_lib_dir orelse b.zig_lib_dir,
+        .main_pkg_path = options.main_pkg_path,
     });
 }
 
@@ -627,6 +646,7 @@ pub const AssemblyOptions = struct {
     target: CrossTarget,
     optimize: std.builtin.Mode,
     max_rss: usize = 0,
+    zig_lib_dir: ?LazyPath = null,
 };
 
 pub fn addAssembly(b: *Build, options: AssemblyOptions) *Step.Compile {
@@ -637,6 +657,7 @@ pub fn addAssembly(b: *Build, options: AssemblyOptions) *Step.Compile {
         .target = options.target,
         .optimize = options.optimize,
         .max_rss = options.max_rss,
+        .zig_lib_dir = options.zig_lib_dir orelse b.zig_lib_dir,
     });
     obj_step.addAssemblyLazyPath(options.source_file.dupe(b));
     return obj_step;
@@ -1259,12 +1280,21 @@ fn printCmd(ally: Allocator, cwd: ?[]const u8, argv: []const []const u8) void {
     std.debug.print("{s}\n", .{text});
 }
 
+/// This creates the install step and adds it to the dependencies of the
+/// top-level install step, using all the default options.
+/// See `addInstallArtifact` for a more flexible function.
 pub fn installArtifact(self: *Build, artifact: *Step.Compile) void {
-    self.getInstallStep().dependOn(&self.addInstallArtifact(artifact).step);
+    self.getInstallStep().dependOn(&self.addInstallArtifact(artifact, .{}).step);
 }
 
-pub fn addInstallArtifact(self: *Build, artifact: *Step.Compile) *Step.InstallArtifact {
+/// This merely creates the step; it does not add it to the dependencies of the
-    return Step.InstallArtifact.create(self, artifact);
+/// top-level install step.
+pub fn addInstallArtifact(
+    self: *Build,
+    artifact: *Step.Compile,
+    options: Step.InstallArtifact.Options,
+) *Step.InstallArtifact {
+    return Step.InstallArtifact.create(self, artifact, options);
 }
 
 ///`dest_rel_path` is relative to prefix path
@@ -1330,6 +1360,7 @@ pub fn addCheckFile(
     return Step.CheckFile.create(b, file_source, options);
 }
 
+/// deprecated: https://github.com/ziglang/zig/issues/14943
 pub fn pushInstalledFile(self: *Build, dir: InstallDir, dest_rel_path: []const u8) void {
     const file = InstalledFile{
         .dir = dir,
@@ -1632,19 +1663,27 @@ pub const GeneratedFile = struct {
     }
 };
 
-pub const FileSource = LazyPath; // DEPRECATED, use LazyPath now
-
 /// A reference to an existing or future path.
 pub const LazyPath = union(enum) {
-    /// A plain file path, relative to build root or absolute.
+    /// A source file path relative to build root.
+    /// This should not be an absolute path, but in an older iteration of the zig build
+    /// system API, it was allowed to be absolute. Absolute paths should use `cwd_relative`.
     path: []const u8,
 
     /// A file that is generated by an interface. Those files usually are
     /// not available until built by a build step.
     generated: *const GeneratedFile,
 
+    /// An absolute path or a path relative to the current working directory of
+    /// the build runner process.
+    /// This is uncommon but used for system environment paths such as `--zig-lib-dir` which
+    /// ignore the file system path of build.zig and instead are relative to the directory from
+    /// which `zig build` was invoked.
+    /// Use of this tag indicates a dependency on the host system.
+    cwd_relative: []const u8,
+
     /// Returns a new file source that will have a relative path to the build root guaranteed.
-    /// This should be preferred over setting `.path` directly as it documents that the files are in the project directory.
+    /// Asserts the parameter is not an absolute path.
     pub fn relative(path: []const u8) LazyPath {
         std.debug.assert(!std.fs.path.isAbsolute(path));
         return LazyPath{ .path = path };
@@ -1654,7 +1693,7 @@ pub const LazyPath = union(enum) {
     /// Either returns the path or `"generated"`.
     pub fn getDisplayName(self: LazyPath) []const u8 {
         return switch (self) {
-            .path => self.path,
+            .path, .cwd_relative => self.path,
             .generated => "generated",
         };
     }
@@ -1662,26 +1701,34 @@ pub const LazyPath = union(enum) {
     /// Adds dependencies this file source implies to the given step.
     pub fn addStepDependencies(self: LazyPath, other_step: *Step) void {
         switch (self) {
-            .path => {},
+            .path, .cwd_relative => {},
             .generated => |gen| other_step.dependOn(gen.step),
         }
     }
 
-    /// Should only be called during make(), returns a path relative to the build root or absolute.
+    /// Returns a path relative to the current process's current working directory, suitable
+    /// for direct file system operations.
+    ///
+    /// Intended to be used during the make phase only.
     pub fn getPath(self: LazyPath, src_builder: *Build) []const u8 {
         return getPath2(self, src_builder, null);
     }
 
-    /// Should only be called during make(), returns a path relative to the build root or absolute.
+    /// Returns a path relative to the current process's current working directory, suitable
-    /// asking_step is only used for debugging purposes; it's the step being run that is asking for
+    /// for direct file system operations.
-    /// the path.
+    ///
+    /// Intended to be used during the make phase only.
+    ///
+    /// `asking_step` is only used for debugging purposes; it's the step being
+    /// run that is asking for the path.
     pub fn getPath2(self: LazyPath, src_builder: *Build, asking_step: ?*Step) []const u8 {
         switch (self) {
             .path => |p| return src_builder.pathFromRoot(p),
+            .cwd_relative => |p| return p,
             .generated => |gen| return gen.path orelse {
                 std.debug.getStderrMutex().lock();
                 const stderr = std.io.getStdErr();
-                build_util.dumpBadGetPathHelp(gen.step, stderr, src_builder, asking_step) catch {};
+                dumpBadGetPathHelp(gen.step, stderr, src_builder, asking_step) catch {};
                 @panic("misconfigured build script");
             },
         }
@@ -1691,11 +1738,60 @@ pub const LazyPath = union(enum) {
     pub fn dupe(self: LazyPath, b: *Build) LazyPath {
         return switch (self) {
             .path => |p| .{ .path = b.dupePath(p) },
+            .cwd_relative => |p| .{ .cwd_relative = b.dupePath(p) },
             .generated => |gen| .{ .generated = gen },
         };
     }
 };
 
+/// In this function the stderr mutex has already been locked.
+pub fn dumpBadGetPathHelp(
+    s: *Step,
+    stderr: fs.File,
+    src_builder: *Build,
+    asking_step: ?*Step,
+) anyerror!void {
+    const w = stderr.writer();
+    try w.print(
+        \\getPath() was called on a GeneratedFile that wasn't built yet.
+        \\  source package path: {s}
+        \\  Is there a missing Step dependency on step '{s}'?
+        \\
+    , .{
+        src_builder.build_root.path orelse ".",
+        s.name,
+    });
+
+    const tty_config = std.io.tty.detectConfig(stderr);
+    tty_config.setColor(w, .red) catch {};
+    try stderr.writeAll("    The step was created by this stack trace:\n");
+    tty_config.setColor(w, .reset) catch {};
+
+    const debug_info = std.debug.getSelfDebugInfo() catch |err| {
+        try w.print("Unable to dump stack trace: Unable to open debug info: {s}\n", .{@errorName(err)});
+        return;
+    };
+    const ally = debug_info.allocator;
+    std.debug.writeStackTrace(s.getStackTrace(), w, ally, debug_info, tty_config) catch |err| {
+        try stderr.writer().print("Unable to dump stack trace: {s}\n", .{@errorName(err)});
+        return;
+    };
+    if (asking_step) |as| {
+        tty_config.setColor(w, .red) catch {};
+        try stderr.writeAll("    The step that is missing a dependency on the above step was created by this stack trace:\n");
+        tty_config.setColor(w, .reset) catch {};
+
+        std.debug.writeStackTrace(as.getStackTrace(), w, ally, debug_info, tty_config) catch |err| {
+            try stderr.writer().print("Unable to dump stack trace: {s}\n", .{@errorName(err)});
+            return;
+        };
+    }
+
+    tty_config.setColor(w, .red) catch {};
+    try stderr.writeAll("    Hope that helps. Proceeding to panic.\n");
+    tty_config.setColor(w, .reset) catch {};
+}
+
 /// Allocates a new string for assigning a value to a named macro.
 /// If the value is omitted, it is set to 1.
 /// `name` and `value` need not live longer than the function call.

lib/std/Build/Step.zig

@@ -423,17 +423,9 @@ pub fn evalZigProcess(
         });
     }
 
-    if (s.cast(Compile)) |compile| {
-        if (compile.generated_bin == null) // TODO(xq): How to handle this properly?!
     return result;
 }
 
-    return result orelse return s.fail(
-        "the following command failed to communicate the compilation result:\n{s}",
-        .{try allocPrintCmd(arena, null, argv)},
-    );
-}
-
 fn sendMessage(file: std.fs.File, tag: std.zig.Client.Message.Tag) !void {
     const header: std.zig.Client.Message.Header = .{
         .tag = tag,

lib/std/Build/Step/Compile.zig

@@ -21,8 +21,6 @@ const InstallDir = std.Build.InstallDir;
 const GeneratedFile = std.Build.GeneratedFile;
 const Compile = @This();
 
-const build_util = @import("../util.zig");
-
 pub const base_id: Step.Id = .compile;
 
 step: Step,
@@ -68,7 +66,9 @@ max_memory: ?u64 = null,
 shared_memory: bool = false,
 global_base: ?u64 = null,
 c_std: std.Build.CStd,
+/// Set via options; intended to be read-only after that.
 zig_lib_dir: ?LazyPath,
+/// Set via options; intended to be read-only after that.
 main_pkg_path: ?LazyPath,
 exec_cmd_args: ?[]const ?[]const u8,
 filter: ?[]const u8,
@@ -80,12 +80,7 @@ wasi_exec_model: ?std.builtin.WasiExecModel = null,
 export_symbol_names: []const []const u8 = &.{},
 
 root_src: ?LazyPath,
-out_h_filename: []const u8,
-out_ll_filename: []const u8,
-out_bc_filename: []const u8,
-out_asm_filename: []const u8,
 out_lib_filename: []const u8,
-out_pdb_filename: []const u8,
 modules: std.StringArrayHashMap(*Module),
 
 link_objects: ArrayList(LinkObject),
@@ -96,8 +91,6 @@ is_linking_libc: bool,
 is_linking_libcpp: bool,
 vcpkg_bin_path: ?[]const u8 = null,
 
-/// This may be set in order to override the default install directory
-override_dest_dir: ?InstallDir,
 installed_path: ?[]const u8,
 
 /// Base address for an executable image.
@@ -207,9 +200,7 @@ use_lld: ?bool,
 /// otherwise.
 expect_errors: []const []const u8 = &.{},
 
-force_build: bool,
+emit_directory: ?*GeneratedFile,
-
-emit_directory: GeneratedFile,
 
 generated_docs: ?*GeneratedFile,
 generated_asm: ?*GeneratedFile,
@@ -221,6 +212,7 @@ generated_llvm_ir: ?*GeneratedFile,
 generated_h: ?*GeneratedFile,
 
 pub const CSourceFiles = struct {
+    /// Relative to the build root.
     files: []const []const u8,
     flags: []const []const u8,
 };
@@ -289,6 +281,8 @@ pub const Options = struct {
     single_threaded: ?bool = null,
     use_llvm: ?bool = null,
     use_lld: ?bool = null,
+    zig_lib_dir: ?LazyPath = null,
+    main_pkg_path: ?LazyPath = null,
 };
 
 pub const BuildId = union(enum) {
@@ -376,17 +370,6 @@ pub const Kind = enum {
 
 pub const Linkage = enum { dynamic, static };
 
-pub const EmitOption = enum {
-    docs,
-    @"asm",
-    bin,
-    pdb,
-    implib,
-    llvm_bc,
-    llvm_ir,
-    h,
-};
-
 pub fn create(owner: *std.Build, options: Options) *Compile {
     const name = owner.dupe(options.name);
     const root_src: ?LazyPath = if (options.root_source_file) |rsrc| rsrc.dupe(owner) else null;
@@ -451,12 +434,7 @@ pub fn create(owner: *std.Build, options: Options) *Compile {
         }),
         .version = options.version,
         .out_filename = out_filename,
-        .out_h_filename = owner.fmt("{s}.h", .{name}),
-        .out_ll_filename = owner.fmt("{s}.bc", .{name}),
-        .out_bc_filename = owner.fmt("{s}.ll", .{name}),
-        .out_asm_filename = owner.fmt("{s}.s", .{name}),
         .out_lib_filename = undefined,
-        .out_pdb_filename = owner.fmt("{s}.pdb", .{name}),
         .major_only_filename = null,
         .name_only_filename = null,
         .modules = std.StringArrayHashMap(*Module).init(owner.allocator),
@@ -477,14 +455,10 @@ pub fn create(owner: *std.Build, options: Options) *Compile {
         .disable_sanitize_c = false,
         .sanitize_thread = false,
         .rdynamic = false,
-        .override_dest_dir = null,
         .installed_path = null,
         .force_undefined_symbols = StringHashMap(void).init(owner.allocator),
 
-        .force_build = false,
+        .emit_directory = null,
-
-        .emit_directory = GeneratedFile{ .step = &self.step },
-
         .generated_docs = null,
         .generated_asm = null,
         .generated_bin = null,
@@ -503,6 +477,16 @@ pub fn create(owner: *std.Build, options: Options) *Compile {
         .use_lld = options.use_lld,
     };
 
+    if (options.zig_lib_dir) |lp| {
+        self.zig_lib_dir = lp.dupe(self.step.owner);
+        lp.addStepDependencies(&self.step);
+    }
+
+    if (options.main_pkg_path) |lp| {
+        self.main_pkg_path = lp.dupe(self.step.owner);
+        lp.addStepDependencies(&self.step);
+    }
+
     if (self.kind == .lib) {
         if (self.linkage != null and self.linkage.? == .static) {
             self.out_lib_filename = self.out_filename;
@@ -636,7 +620,8 @@ pub fn checkObject(self: *Compile) *Step.CheckObject {
     return Step.CheckObject.create(self.step.owner, self.getEmittedBin(), self.target_info.target.ofmt);
 }
 
-pub const setLinkerScriptPath = setLinkerScript; // DEPRECATED, use setLinkerScript
+/// deprecated: use `setLinkerScript`
+pub const setLinkerScriptPath = setLinkerScript;
 
 pub fn setLinkerScript(self: *Compile, source: LazyPath) void {
     const b = self.step.owner;
@@ -700,12 +685,17 @@ pub fn isStaticLibrary(self: *Compile) bool {
 
 pub fn producesPdbFile(self: *Compile) bool {
     // TODO: Is this right? Isn't PDB for *any* PE/COFF file?
+    // TODO: just share this logic with the compiler, silly!
     if (!self.target.isWindows() and !self.target.isUefi()) return false;
     if (self.target.getObjectFormat() == .c) return false;
     if (self.strip == true or (self.strip == null and self.optimize == .ReleaseSmall)) return false;
     return self.isDynamicLibrary() or self.kind == .exe or self.kind == .@"test";
 }
 
+pub fn producesImplib(self: *Compile) bool {
+    return self.isDynamicLibrary() and self.target.isWindows();
+}
+
 pub fn linkLibC(self: *Compile) void {
     self.is_linking_libc = true;
 }
@@ -961,16 +951,6 @@ pub fn setVerboseCC(self: *Compile, value: bool) void {
     self.verbose_cc = value;
 }
 
-pub fn overrideZigLibDir(self: *Compile, dir_path: LazyPath) void {
-    self.zig_lib_dir = dir_path.dupe(self.step.owner);
-    dir_path.addStepDependencies(&self.step);
-}
-
-pub fn setMainPkgPath(self: *Compile, dir_path: LazyPath) void {
-    self.main_pkg_path = dir_path.dupe(self.step.owner);
-    dir_path.addStepDependencies(&self.step);
-}
-
 pub fn setLibCFile(self: *Compile, libc_file: ?LazyPath) void {
     const b = self.step.owner;
     self.libc_file = if (libc_file) |f| f.dupe(b) else null;
@@ -987,34 +967,17 @@ fn getEmittedFileGeneric(self: *Compile, output_file: *?*GeneratedFile) LazyPath
     return .{ .generated = generated_file };
 }
 
-/// Disables the panic in the build evaluation if nothing is emitted.
+/// deprecated: use `getEmittedBinDirectory`
-///
+pub const getOutputDirectorySource = getEmittedBinDirectory;
-/// Unless for compilation tests this is a code smell.
+
-pub fn forceBuild(self: *Compile) void {
+/// Returns the path to the directory that contains the emitted binary file.
-    self.force_build = true;
+pub fn getEmittedBinDirectory(self: *Compile) LazyPath {
+    _ = self.getEmittedBin();
+    return self.getEmittedFileGeneric(&self.emit_directory);
 }
 
-pub fn forceEmit(self: *Compile, emit: EmitOption) void {
+/// deprecated: use `getEmittedBin`
-    switch (emit) {
+pub const getOutputSource = getEmittedBin;
-        .docs => _ = self.getEmittedDocs(),
-        .@"asm" => _ = self.getEmittedAsm(),
-        .bin => _ = self.getEmittedBin(),
-        .pdb => _ = self.getEmittedPdb(),
-        .implib => _ = self.getEmittedImplib(),
-        .llvm_bc => _ = self.getEmittedLlvmBc(),
-        .llvm_ir => _ = self.getEmittedLlvmIr(),
-        .h => _ = self.getEmittedH(),
-    }
-}
-
-pub const getOutputDirectorySource = getEmitDirectory; // DEPRECATED, use getEmitDirectory
-
-/// Returns the path to the output directory.
-pub fn getEmitDirectory(self: *Compile) LazyPath {
-    return .{ .generated = &self.emit_directory };
-}
-
-pub const getOutputSource = getEmittedBin; // DEPRECATED, use getEmittedBin
 
 /// Returns the path to the generated executable, library or object file.
 /// To run an executable built with zig build, use `run`, or create an install step and invoke it.
@@ -1022,15 +985,18 @@ pub fn getEmittedBin(self: *Compile) LazyPath {
     return self.getEmittedFileGeneric(&self.generated_bin);
 }
 
-pub const getOutputLibSource = getEmittedImplib; // DEPRECATED, use getEmittedImplib
+/// deprecated: use `getEmittedImplib`
+pub const getOutputLibSource = getEmittedImplib;
 
-/// Returns the path to the generated import library. This function can only be called for libraries.
+/// Returns the path to the generated import library.
+/// This function can only be called for libraries.
 pub fn getEmittedImplib(self: *Compile) LazyPath {
     assert(self.kind == .lib);
     return self.getEmittedFileGeneric(&self.generated_implib);
 }
 
-pub const getOutputHSource = getEmittedH; // DEPRECATED, use getEmittedH
+/// deprecated: use `getEmittedH`
+pub const getOutputHSource = getEmittedH;
 
 /// Returns the path to the generated header file.
 /// This function can only be called for libraries or objects.
@@ -1039,11 +1005,14 @@ pub fn getEmittedH(self: *Compile) LazyPath {
     return self.getEmittedFileGeneric(&self.generated_h);
 }
 
-pub const getOutputPdbSource = getEmittedPdb; // DEPRECATED, use getEmittedPdb
+/// deprecated: use `getEmittedPdb`.
+pub const getOutputPdbSource = getEmittedPdb;
 
-/// Returns the generated PDB file. This function can only be called for Windows and UEFI.
+/// Returns the generated PDB file.
+/// If the compilation does not produce a PDB file, this causes a FileNotFound error
+/// at build time.
 pub fn getEmittedPdb(self: *Compile) LazyPath {
-    assert(self.producesPdbFile());
+    _ = self.getEmittedBin();
     return self.getEmittedFileGeneric(&self.generated_pdb);
 }
 
@@ -1198,13 +1167,11 @@ pub fn setExecCmd(self: *Compile, args: []const ?[]const u8) void {
 }
 
 fn linkLibraryOrObject(self: *Compile, other: *Compile) void {
-    other.forceEmit(.bin);
+    other.getEmittedBin().addStepDependencies(&self.step);
-
+    if (other.target.isWindows() and other.isDynamicLibrary()) {
-    if (other.target.isWindows() and other.isDynamicLibrary()) { // TODO(xq): Is this the correct logic here?
+        other.getEmittedImplib().addStepDependencies(&self.step);
-        other.forceEmit(.implib);
     }
 
-    self.step.dependOn(&other.step);
     self.link_objects.append(.{ .other_step = other }) catch @panic("OOM");
     self.include_dirs.append(.{ .other_step = other }) catch @panic("OOM");
 
@@ -1330,7 +1297,7 @@ fn getGeneratedFilePath(self: *Compile, comptime tag_name: []const u8, asking_st
         std.debug.getStderrMutex().lock();
         const stderr = std.io.getStdErr();
 
-        build_util.dumpBadGetPathHelp(&self.step, stderr, self.step.owner, asking_step) catch {};
+        std.Build.dumpBadGetPathHelp(&self.step, stderr, self.step.owner, asking_step) catch {};
 
         @panic("missing emit option for " ++ tag_name);
     };
@@ -1339,7 +1306,7 @@ fn getGeneratedFilePath(self: *Compile, comptime tag_name: []const u8, asking_st
         std.debug.getStderrMutex().lock();
         const stderr = std.io.getStdErr();
 
-        build_util.dumpBadGetPathHelp(&self.step, stderr, self.step.owner, asking_step) catch {};
+        std.Build.dumpBadGetPathHelp(&self.step, stderr, self.step.owner, asking_step) catch {};
 
         @panic(tag_name ++ " is null. Is there a missing step dependency?");
     };
@@ -1432,11 +1399,12 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
                         break :l;
                     }
 
-                    // TODO(xq): Is that the right way?
+                    // For DLLs, we gotta link against the implib. For
-                    const full_path_lib = if (other.isDynamicLibrary() and other.target.isWindows())
+                    // everything else, we directly link against the library file.
-                        other.getGeneratedFilePath("generated_implib", &self.step) // For DLLs, we gotta link against the implib,
+                    const full_path_lib = if (other.producesImplib())
+                        other.getGeneratedFilePath("generated_implib", &self.step)
                     else
-                        other.getGeneratedFilePath("generated_bin", &self.step); // for everything else, we directly link against the library file
+                        other.getGeneratedFilePath("generated_bin", &self.step);
                     try zig_args.append(full_path_lib);
 
                     if (other.linkage == Linkage.dynamic and !self.target.isWindows()) {
@@ -1579,36 +1547,13 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
     if (b.verbose_cc or self.verbose_cc) try zig_args.append("--verbose-cc");
     if (b.verbose_llvm_cpu_features) try zig_args.append("--verbose-llvm-cpu-features");
 
-    const Emitter = struct {
+    if (self.generated_asm != null) try zig_args.append("-femit-asm");
-        ptr: ?*GeneratedFile,
+    if (self.generated_bin == null) try zig_args.append("-fno-emit-bin");
-        emit_suffix: []const u8,
+    if (self.generated_docs != null) try zig_args.append("-femit-docs");
-    };
+    if (self.generated_implib != null) try zig_args.append("-femit-implib");
-
+    if (self.generated_llvm_bc != null) try zig_args.append("-femit-llvm-bc");
-    const generated_files = [_]Emitter{
+    if (self.generated_llvm_ir != null) try zig_args.append("-femit-llvm-ir");
-        .{ .ptr = self.generated_asm, .emit_suffix = "asm" },
+    if (self.generated_h != null) try zig_args.append("-femit-h");
-        .{ .ptr = self.generated_bin, .emit_suffix = "bin" },
-        .{ .ptr = self.generated_docs, .emit_suffix = "docs" },
-        .{ .ptr = self.generated_implib, .emit_suffix = "implib" },
-        .{ .ptr = self.generated_llvm_bc, .emit_suffix = "llvm-bc" },
-        .{ .ptr = self.generated_llvm_ir, .emit_suffix = "llvm-ir" },
-        .{ .ptr = self.generated_h, .emit_suffix = "h" },
-    };
-    var any_emitted_file = false;
-    for (generated_files) |file| {
-        try zig_args.append(if (file.ptr != null)
-            b.fmt("-femit-{s}", .{file.emit_suffix})
-        else
-            b.fmt("-fno-emit-{s}", .{file.emit_suffix}));
-
-        if (file.ptr != null) any_emitted_file = true;
-    }
-
-    if (!any_emitted_file and !self.force_build) {
-        std.debug.getStderrMutex().lock();
-        const stderr = std.io.getStdErr();
-        build_util.dumpBadGetPathHelp(&self.step, stderr, self.step.owner, null) catch {};
-        std.debug.panic("Artifact '{s}' has no emit options set, but it is made. Did you forget to call `.getEmitted*()`? If not, use `.forceBuild()` or `.forceEmit(…)` to make sure it builds anyways.", .{self.name});
-    }
 
     try addFlag(&zig_args, "strip", self.strip);
     try addFlag(&zig_args, "unwind-tables", self.unwind_tables);
@@ -1895,7 +1840,7 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
         zig_args.appendAssumeCapacity("-rpath");
 
         if (self.target_info.target.isDarwin()) switch (rpath) {
-            .path => |path| {
+            .path, .cwd_relative => |path| {
                 // On Darwin, we should not try to expand special runtime paths such as
                 // * @executable_path
                 // * @loader_path
@@ -1993,9 +1938,6 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
     if (self.zig_lib_dir) |dir| {
         try zig_args.append("--zig-lib-dir");
         try zig_args.append(dir.getPath(b));
-    } else if (b.zig_lib_dir) |dir| {
-        try zig_args.append("--zig-lib-dir");
-        try zig_args.append(dir);
     }
 
     if (self.main_pkg_path) |dir| {
@@ -2093,37 +2035,30 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
     if (maybe_output_bin_path) |output_bin_path| {
         const output_dir = fs.path.dirname(output_bin_path).?;
 
-        self.emit_directory.path = output_dir;
+        if (self.emit_directory) |lp| {
+            lp.path = output_dir;
+        }
 
         // -femit-bin[=path]         (default) Output machine code
         if (self.generated_bin) |bin| {
-            bin.path = b.pathJoin(
+            bin.path = b.pathJoin(&.{ output_dir, self.out_filename });
-                &.{ output_dir, self.out_filename },
-            );
         }
 
+        const sep = std.fs.path.sep;
+
         // output PDB if someone requested it
         if (self.generated_pdb) |pdb| {
-            std.debug.assert(self.producesPdbFile());
+            pdb.path = b.fmt("{s}{c}{s}.pdb", .{ output_dir, sep, self.name });
-            pdb.path = b.pathJoin(
-                &.{ output_dir, self.out_pdb_filename },
-            );
         }
 
         // -femit-implib[=path]      (default) Produce an import .lib when building a Windows DLL
-        if (self.kind == .lib) {
+        if (self.generated_implib) |implib| {
-            if (self.generated_implib) |lib| {
+            implib.path = b.fmt("{s}{c}{s}.lib", .{ output_dir, sep, self.name });
-                lib.path = b.pathJoin(
-                    &.{ output_dir, self.out_lib_filename },
-                );
-            }
         }
 
         // -femit-h[=path]           Generate a C header file (.h)
-        if (self.generated_h) |lazy_path| {
+        if (self.generated_h) |lp| {
-            lazy_path.path = b.pathJoin(
+            lp.path = b.fmt("{s}{c}{s}.h", .{ output_dir, sep, self.name });
-                &.{ output_dir, self.out_h_filename },
-            );
         }
 
         // -femit-docs[=path]        Create a docs/ dir with html documentation
@@ -2132,24 +2067,18 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
         }
 
         // -femit-asm[=path]         Output .s (assembly code)
-        if (self.generated_asm) |lazy_path| {
+        if (self.generated_asm) |lp| {
-            lazy_path.path = b.pathJoin(
+            lp.path = b.fmt("{s}{c}{s}.s", .{ output_dir, sep, self.name });
-                &.{ output_dir, self.out_asm_filename },
-            );
         }
 
         // -femit-llvm-ir[=path]     Produce a .ll file with optimized LLVM IR (requires LLVM extensions)
-        if (self.generated_llvm_ir) |lazy_path| {
+        if (self.generated_llvm_ir) |lp| {
-            lazy_path.path = b.pathJoin(
+            lp.path = b.fmt("{s}{c}{s}.ll", .{ output_dir, sep, self.name });
-                &.{ output_dir, self.out_ll_filename },
-            );
         }
 
         // -femit-llvm-bc[=path]     Produce an optimized LLVM module as a .bc file (requires LLVM extensions)
-        if (self.generated_llvm_bc) |lazy_path| {
+        if (self.generated_llvm_bc) |lp| {
-            lazy_path.path = b.pathJoin(
+            lp.path = b.fmt("{s}{c}{s}.bc", .{ output_dir, sep, self.name });
-                &.{ output_dir, self.out_bc_filename },
-            );
         }
     }
 

lib/std/Build/Step/ConfigHeader.zig

@@ -15,7 +15,8 @@ pub const Style = union(enum) {
     /// Start with nothing, like blank, and output a nasm .asm file.
     nasm,
 
-    pub const getFileSource = getPath; // DEPRECATED, use getPath
+    /// deprecated: use `getPath`
+    pub const getFileSource = getPath;
 
     pub fn getPath(style: Style) ?std.Build.LazyPath {
         switch (style) {
@@ -100,9 +101,10 @@ pub fn addValues(self: *ConfigHeader, values: anytype) void {
     return addValuesInner(self, values) catch @panic("OOM");
 }
 
-pub const getFileSource = getTemplate; // DEPRECATED, use getOutput
+/// deprecated: use `getOutput`
+pub const getFileSource = getOutput;
 
-pub fn getTemplate(self: *ConfigHeader) std.Build.LazyPath {
+pub fn getOutput(self: *ConfigHeader) std.Build.LazyPath {
     return .{ .generated = &self.output_file };
 }
 

lib/std/Build/Step/InstallArtifact.zig

@@ -3,67 +3,117 @@ const Step = std.Build.Step;
 const InstallDir = std.Build.InstallDir;
 const InstallArtifact = @This();
 const fs = std.fs;
+const LazyPath = std.Build.LazyPath;
+
+step: Step,
+
+dest_dir: ?InstallDir,
+dest_sub_path: []const u8,
+emitted_bin: ?LazyPath,
+
+implib_dir: ?InstallDir,
+emitted_implib: ?LazyPath,
+
+pdb_dir: ?InstallDir,
+emitted_pdb: ?LazyPath,
+
+h_dir: ?InstallDir,
+emitted_h: ?LazyPath,
+
+dylib_symlinks: ?DylibSymlinkInfo,
+
+artifact: *Step.Compile,
+
+const DylibSymlinkInfo = struct {
+    major_only_filename: []const u8,
+    name_only_filename: []const u8,
+};
 
 pub const base_id = .install_artifact;
 
-step: Step,
+pub const Options = struct {
-artifact: *Step.Compile,
+    /// Which installation directory to put the main output file into.
-dest_dir: InstallDir,
+    dest_dir: Dir = .default,
-pdb_dir: ?InstallDir,
+    pdb_dir: Dir = .default,
-h_dir: ?InstallDir,
+    h_dir: Dir = .default,
-/// If non-null, adds additional path components relative to dest_dir, and
+    implib_dir: Dir = .default,
-/// overrides the basename of the Compile step.
-dest_sub_path: ?[]const u8,
 
-pub fn create(owner: *std.Build, artifact: *Step.Compile) *InstallArtifact {
+    /// Whether to install symlinks along with dynamic libraries.
+    dylib_symlinks: ?bool = null,
+    /// If non-null, adds additional path components relative to bin dir, and
+    /// overrides the basename of the Compile step for installation purposes.
+    dest_sub_path: ?[]const u8 = null,
+
+    pub const Dir = union(enum) {
+        disabled,
+        default,
+        override: InstallDir,
+    };
+};
+
+pub fn create(owner: *std.Build, artifact: *Step.Compile, options: Options) *InstallArtifact {
     const self = owner.allocator.create(InstallArtifact) catch @panic("OOM");
-    self.* = InstallArtifact{
+    const dest_dir: ?InstallDir = switch (options.dest_dir) {
+        .disabled => null,
+        .default => switch (artifact.kind) {
+            .obj => @panic("object files have no standard installation procedure"),
+            .exe, .@"test" => InstallDir{ .bin = {} },
+            .lib => InstallDir{ .lib = {} },
+        },
+        .override => |o| o,
+    };
+    self.* = .{
         .step = Step.init(.{
             .id = base_id,
             .name = owner.fmt("install {s}", .{artifact.name}),
             .owner = owner,
             .makeFn = make,
         }),
-        .artifact = artifact,
+        .dest_dir = dest_dir,
-        .dest_dir = artifact.override_dest_dir orelse switch (artifact.kind) {
+        .pdb_dir = switch (options.pdb_dir) {
-            .obj => @panic("Cannot install a .obj build artifact."),
+            .disabled => null,
-            .exe, .@"test" => InstallDir{ .bin = {} },
+            .default => if (artifact.producesPdbFile()) dest_dir else null,
-            .lib => InstallDir{ .lib = {} },
+            .override => |o| o,
         },
-        .pdb_dir = if (artifact.producesPdbFile()) blk: {
+        .h_dir = switch (options.h_dir) {
-            if (artifact.kind == .exe or artifact.kind == .@"test") {
+            .disabled => null,
-                break :blk InstallDir{ .bin = {} };
+            .default => switch (artifact.kind) {
-            } else {
+                .lib => .header,
-                break :blk InstallDir{ .lib = {} };
+                else => null,
-            }
+            },
+            .override => |o| o,
+        },
+        .implib_dir = switch (options.implib_dir) {
+            .disabled => null,
+            .default => if (artifact.producesImplib()) dest_dir else null,
+            .override => |o| o,
+        },
+
+        .dylib_symlinks = if (options.dylib_symlinks orelse (dest_dir != null and
+            artifact.isDynamicLibrary() and
+            artifact.version != null and
+            artifact.target.wantSharedLibSymLinks())) .{
+            .major_only_filename = artifact.major_only_filename.?,
+            .name_only_filename = artifact.name_only_filename.?,
         } else null,
-        .h_dir = if (artifact.kind == .lib and artifact.generated_h != null) .header else null,
+
-        .dest_sub_path = null,
+        .dest_sub_path = options.dest_sub_path orelse artifact.out_filename,
+
+        .emitted_bin = null,
+        .emitted_pdb = null,
+        .emitted_h = null,
+        .emitted_implib = null,
+
+        .artifact = artifact,
     };
+
     self.step.dependOn(&artifact.step);
 
-    artifact.forceEmit(.bin);
+    if (self.dest_dir != null) self.emitted_bin = artifact.getEmittedBin();
+    if (self.pdb_dir != null) self.emitted_pdb = artifact.getEmittedPdb();
+    if (self.h_dir != null) self.emitted_h = artifact.getEmittedH();
+    if (self.implib_dir != null) self.emitted_implib = artifact.getEmittedImplib();
 
-    owner.pushInstalledFile(self.dest_dir, artifact.out_filename);
-    if (self.artifact.isDynamicLibrary()) {
-        if (artifact.major_only_filename) |name| {
-            owner.pushInstalledFile(.lib, name);
-        }
-        if (artifact.name_only_filename) |name| {
-            owner.pushInstalledFile(.lib, name);
-        }
-        if (self.artifact.target.isWindows()) {
-            owner.pushInstalledFile(.lib, artifact.out_lib_filename);
-        }
-    }
-    if (self.pdb_dir) |pdb_dir| {
-        _ = artifact.getEmittedPdb(); // force creation
-        owner.pushInstalledFile(pdb_dir, artifact.out_pdb_filename);
-    }
-    if (self.h_dir) |h_dir| {
-        _ = artifact.getEmittedH(); // force creation
-        owner.pushInstalledFile(h_dir, artifact.out_h_filename);
-    }
     return self;
 }
 
@@ -71,35 +121,30 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
     _ = prog_node;
     const self = @fieldParentPtr(InstallArtifact, "step", step);
     const dest_builder = step.owner;
-
-    const dest_sub_path = if (self.dest_sub_path) |sub_path| sub_path else self.artifact.out_filename;
-    const full_dest_path = dest_builder.getInstallPath(self.dest_dir, dest_sub_path);
     const cwd = fs.cwd();
 
     var all_cached = true;
 
-    {
+    if (self.dest_dir) |dest_dir| {
-        const full_src_path = self.artifact.generated_bin.?.path.?;
+        const full_dest_path = dest_builder.getInstallPath(dest_dir, self.dest_sub_path);
+        const full_src_path = self.emitted_bin.?.getPath2(step.owner, step);
         const p = fs.Dir.updateFile(cwd, full_src_path, cwd, full_dest_path, .{}) catch |err| {
             return step.fail("unable to update file from '{s}' to '{s}': {s}", .{
                 full_src_path, full_dest_path, @errorName(err),
             });
         };
         all_cached = all_cached and p == .fresh;
+
+        if (self.dylib_symlinks) |dls| {
+            try Step.Compile.doAtomicSymLinks(step, full_dest_path, dls.major_only_filename, dls.name_only_filename);
         }
 
-    if (self.artifact.isDynamicLibrary() and
+        self.artifact.installed_path = full_dest_path;
-        self.artifact.version != null and
-        self.artifact.target.wantSharedLibSymLinks())
-    {
-        try Step.Compile.doAtomicSymLinks(step, full_dest_path, self.artifact.major_only_filename.?, self.artifact.name_only_filename.?);
     }
-    if (self.artifact.isDynamicLibrary() and
+
-        self.artifact.target.isWindows() and
+    if (self.implib_dir) |implib_dir| {
-        self.artifact.generated_implib != null)
+        const full_src_path = self.emitted_implib.?.getPath2(step.owner, step);
-    {
+        const full_implib_path = dest_builder.getInstallPath(implib_dir, fs.path.basename(full_src_path));
-        const full_src_path = self.artifact.generated_implib.?.path.?;
-        const full_implib_path = dest_builder.getInstallPath(self.dest_dir, self.artifact.out_lib_filename);
         const p = fs.Dir.updateFile(cwd, full_src_path, cwd, full_implib_path, .{}) catch |err| {
             return step.fail("unable to update file from '{s}' to '{s}': {s}", .{
                 full_src_path, full_implib_path, @errorName(err),
@@ -107,9 +152,10 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
         };
         all_cached = all_cached and p == .fresh;
     }
+
     if (self.pdb_dir) |pdb_dir| {
-        const full_src_path = self.artifact.generated_pdb.?.path.?;
+        const full_src_path = self.emitted_pdb.?.getPath2(step.owner, step);
-        const full_pdb_path = dest_builder.getInstallPath(pdb_dir, self.artifact.out_pdb_filename);
+        const full_pdb_path = dest_builder.getInstallPath(pdb_dir, fs.path.basename(full_src_path));
         const p = fs.Dir.updateFile(cwd, full_src_path, cwd, full_pdb_path, .{}) catch |err| {
             return step.fail("unable to update file from '{s}' to '{s}': {s}", .{
                 full_src_path, full_pdb_path, @errorName(err),
@@ -117,9 +163,10 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
         };
         all_cached = all_cached and p == .fresh;
     }
+
     if (self.h_dir) |h_dir| {
-        const full_src_path = self.artifact.generated_h.?.path.?;
+        const full_src_path = self.emitted_h.?.getPath2(step.owner, step);
-        const full_h_path = dest_builder.getInstallPath(h_dir, self.artifact.out_h_filename);
+        const full_h_path = dest_builder.getInstallPath(h_dir, fs.path.basename(full_src_path));
         const p = fs.Dir.updateFile(cwd, full_src_path, cwd, full_h_path, .{}) catch |err| {
             return step.fail("unable to update file from '{s}' to '{s}': {s}", .{
                 full_src_path, full_h_path, @errorName(err),
@@ -127,6 +174,6 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
         };
         all_cached = all_cached and p == .fresh;
     }
-    self.artifact.installed_path = full_dest_path;
+
     step.result_cached = all_cached;
 }

lib/std/Build/Step/ObjCopy.zig

@@ -60,7 +60,8 @@ pub fn create(
     return self;
 }
 
-pub const getOutputSource = getOutput; // DEPRECATED, use getOutput
+/// deprecated: use getOutput
+pub const getOutputSource = getOutput;
 
 pub fn getOutput(self: *const ObjCopy) std.Build.LazyPath {
     return .{ .generated = &self.output_file };

lib/std/Build/Step/Options.zig

@@ -13,7 +13,7 @@ step: Step,
 generated_file: GeneratedFile,
 
 contents: std.ArrayList(u8),
-args: std.ArrayList(OptionLazyPathArg),
+args: std.ArrayList(Arg),
 
 pub fn create(owner: *std.Build) *Options {
     const self = owner.allocator.create(Options) catch @panic("OOM");
@@ -26,7 +26,7 @@ pub fn create(owner: *std.Build) *Options {
         }),
         .generated_file = undefined,
         .contents = std.ArrayList(u8).init(owner.allocator),
-        .args = std.ArrayList(OptionLazyPathArg).init(owner.allocator),
+        .args = std.ArrayList(Arg).init(owner.allocator),
     };
     self.generated_file = .{ .step = &self.step };
 
@@ -166,7 +166,8 @@ fn printLiteral(out: anytype, val: anytype, indent: u8) !void {
     }
 }
 
-pub const addOptionFileSource = addOptionPath; // DEPRECATED, use addPathOption
+/// deprecated: use `addOptionPath`
+pub const addOptionFileSource = addOptionPath;
 
 /// The value is the path in the cache dir.
 /// Adds a dependency automatically.
@@ -182,14 +183,9 @@ pub fn addOptionPath(
     path.addStepDependencies(&self.step);
 }
 
-/// The value is the path in the cache dir.
+/// Deprecated: use `addOptionPath(options, name, artifact.getEmittedBin())` instead.
-/// Adds a dependency automatically.
 pub fn addOptionArtifact(self: *Options, name: []const u8, artifact: *Step.Compile) void {
-    self.args.append(.{
+    return addOptionPath(self, name, artifact.getEmittedBin());
-        .name = self.step.owner.dupe(name),
-        .artifact = artifact.getEmittedBin,
-    }) catch @panic("OOM");
-    self.step.dependOn(&artifact.step);
 }
 
 pub fn createModule(self: *Options) *std.Build.Module {
@@ -199,7 +195,8 @@ pub fn createModule(self: *Options) *std.Build.Module {
     });
 }
 
-pub const getSource = getOutput; // DEPRECATED, use getOutput
+/// deprecated: use `getOutput`
+pub const getSource = getOutput;
 
 pub fn getOutput(self: *Options) LazyPath {
     return .{ .generated = &self.generated_file };
@@ -226,7 +223,7 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
     var hash = b.cache.hash;
     // Random bytes to make unique. Refresh this with new random bytes when
     // implementation is modified in a non-backwards-compatible way.
-    hash.add(@as(u32, 0x38845ef8));
+    hash.add(@as(u32, 0xad95e922));
     hash.addBytes(self.contents.items);
     const sub_path = "c" ++ fs.path.sep_str ++ hash.final() ++ fs.path.sep_str ++ basename;
 
@@ -291,7 +288,7 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
     }
 }
 
-const OptionLazyPathArg = struct {
+const Arg = struct {
     name: []const u8,
     path: LazyPath,
 };

lib/std/Build/Step/Run.zig

@@ -164,12 +164,9 @@ pub fn enableTestRunnerMode(self: *Run) void {
 }
 
 pub fn addArtifactArg(self: *Run, artifact: *Step.Compile) void {
-    // enforce creation of the binary file by invoking getEmittedBin
     const bin_file = artifact.getEmittedBin();
     bin_file.addStepDependencies(&self.step);
-
     self.argv.append(Arg{ .artifact = artifact }) catch @panic("OOM");
-    self.step.dependOn(&artifact.step);
 }
 
 /// This provides file path as a command line argument to the command being
@@ -201,32 +198,36 @@ pub fn addPrefixedOutputFileArg(
     return .{ .generated = &output.generated_file };
 }
 
-pub const addFileSourceArg = addFileArg; // DEPRECATED, use addFileArg
+/// deprecated: use `addFileArg`
+pub const addFileSourceArg = addFileArg;
 
-pub fn addFileArg(self: *Run, file_source: std.Build.LazyPath) void {
+pub fn addFileArg(self: *Run, lp: std.Build.LazyPath) void {
-    self.addPrefixedFileArg("", file_source);
+    self.addPrefixedFileArg("", lp);
 }
 
-pub const addPrefixedFileSourceArg = addPrefixedFileArg; // DEPRECATED, use addPrefixedFileArg
+// deprecated: use `addPrefixedFileArg`
+pub const addPrefixedFileSourceArg = addPrefixedFileArg;
 
-pub fn addPrefixedFileArg(self: *Run, prefix: []const u8, file_source: std.Build.LazyPath) void {
+pub fn addPrefixedFileArg(self: *Run, prefix: []const u8, lp: std.Build.LazyPath) void {
     const b = self.step.owner;
 
     const prefixed_file_source: PrefixedLazyPath = .{
         .prefix = b.dupe(prefix),
-        .file_source = file_source.dupe(b),
+        .file_source = lp.dupe(b),
     };
     self.argv.append(.{ .file_source = prefixed_file_source }) catch @panic("OOM");
-    file_source.addStepDependencies(&self.step);
+    lp.addStepDependencies(&self.step);
 }
 
-pub const addDirectorySourceArg = addDirectoryArg; // DEPRECATED, use addDirectoryArg
+/// deprecated: use `addDirectoryArg`
+pub const addDirectorySourceArg = addDirectoryArg;
 
 pub fn addDirectoryArg(self: *Run, directory_source: std.Build.LazyPath) void {
     self.addPrefixedDirectoryArg("", directory_source);
 }
 
-pub const addPrefixedDirectorySourceArg = addPrefixedDirectoryArg; // DEPRECATED, use addPrefixedDirectoryArg
+// deprecated: use `addPrefixedDirectoryArg`
+pub const addPrefixedDirectorySourceArg = addPrefixedDirectoryArg;
 
 pub fn addPrefixedDirectoryArg(self: *Run, prefix: []const u8, directory_source: std.Build.LazyPath) void {
     const b = self.step.owner;

lib/std/Build/Step/WriteFile.zig

@@ -28,7 +28,8 @@ pub const File = struct {
     sub_path: []const u8,
     contents: Contents,
 
-    pub const getFileSource = getPath; // DEPRECATED, use getPath
+    /// deprecated: use `getPath`
+    pub const getFileSource = getPath;
 
     pub fn getPath(self: *File) std.Build.LazyPath {
         return .{ .generated = &self.generated_file };

lib/std/Build/util.zig

@@ -1,53 +0,0 @@
-const std = @import("std");
-const fs = std.fs;
-
-const Build = std.Build;
-const Step = std.Build.Step;
-
-/// In this function the stderr mutex has already been locked.
-pub fn dumpBadGetPathHelp(
-    s: *Step,
-    stderr: fs.File,
-    src_builder: *Build,
-    asking_step: ?*Step,
-) anyerror!void {
-    const w = stderr.writer();
-    try w.print(
-        \\getPath() was called on a GeneratedFile that wasn't built yet.
-        \\  source package path: {s}
-        \\  Is there a missing Step dependency on step '{s}'?
-        \\
-    , .{
-        src_builder.build_root.path orelse ".",
-        s.name,
-    });
-
-    const tty_config = std.io.tty.detectConfig(stderr);
-    tty_config.setColor(w, .red) catch {};
-    try stderr.writeAll("    The step was created by this stack trace:\n");
-    tty_config.setColor(w, .reset) catch {};
-
-    const debug_info = std.debug.getSelfDebugInfo() catch |err| {
-        try w.print("Unable to dump stack trace: Unable to open debug info: {s}\n", .{@errorName(err)});
-        return;
-    };
-    const ally = debug_info.allocator;
-    std.debug.writeStackTrace(s.getStackTrace(), w, ally, debug_info, tty_config) catch |err| {
-        try stderr.writer().print("Unable to dump stack trace: {s}\n", .{@errorName(err)});
-        return;
-    };
-    if (asking_step) |as| {
-        tty_config.setColor(w, .red) catch {};
-        try stderr.writeAll("    The step that is missing a dependency on the above step was created by this stack trace:\n");
-        tty_config.setColor(w, .reset) catch {};
-
-        std.debug.writeStackTrace(as.getStackTrace(), w, ally, debug_info, tty_config) catch |err| {
-            try stderr.writer().print("Unable to dump stack trace: {s}\n", .{@errorName(err)});
-            return;
-        };
-    }
-
-    tty_config.setColor(w, .red) catch {};
-    try stderr.writeAll("    Hope that helps. Proceeding to panic.\n");
-    tty_config.setColor(w, .reset) catch {};
-}

test/link/glibc_compat/build.zig

@@ -4,7 +4,7 @@ pub fn build(b: *std.Build) void {
     const test_step = b.step("test", "Test");
     b.default_step = test_step;
 
-    inline for (.{ "aarch64-linux-gnu.2.27", "aarch64-linux-gnu.2.34" }) |t| {
+    for ([_][]const u8{ "aarch64-linux-gnu.2.27", "aarch64-linux-gnu.2.34" }) |t| {
         const exe = b.addExecutable(.{
             .name = t,
             .root_source_file = .{ .path = "main.c" },
@@ -13,7 +13,8 @@ pub fn build(b: *std.Build) void {
             ) catch unreachable,
         });
         exe.linkLibC();
-        exe.forceBuild();
+        // TODO: actually test the output
+        _ = exe.getEmittedBin();
         test_step.dependOn(&exe.step);
     }
 }

test/link/macho/dylib/build.zig

@@ -41,8 +41,8 @@ fn add(b: *std.Build, test_step: *std.Build.Step, optimize: std.builtin.Optimize
     });
     exe.addCSourceFile(.{ .file = .{ .path = "main.c" }, .flags = &.{} });
     exe.linkSystemLibrary("a");
-    exe.addLibraryPath(dylib.getEmitDirectory());
+    exe.addLibraryPath(dylib.getEmittedBinDirectory());
-    exe.addRPath(dylib.getEmitDirectory());
+    exe.addRPath(dylib.getEmittedBinDirectory());
     exe.linkLibC();
 
     const check_exe = exe.checkObject();

test/link/macho/needed_library/build.zig

@@ -23,7 +23,6 @@ fn add(b: *std.Build, test_step: *std.Build.Step, optimize: std.builtin.Optimize
     });
     dylib.addCSourceFile(.{ .file = .{ .path = "a.c" }, .flags = &.{} });
     dylib.linkLibC();
-    dylib.forceEmit(.bin); // enforce library creation, we import it below
 
     // -dead_strip_dylibs
     // -needed-la
@@ -35,8 +34,8 @@ fn add(b: *std.Build, test_step: *std.Build.Step, optimize: std.builtin.Optimize
     exe.addCSourceFile(.{ .file = .{ .path = "main.c" }, .flags = &[0][]const u8{} });
     exe.linkLibC();
     exe.linkSystemLibraryNeeded("a");
-    exe.addLibraryPath(dylib.getEmitDirectory());
+    exe.addLibraryPath(dylib.getEmittedBinDirectory());
-    exe.addRPath(dylib.getEmitDirectory());
+    exe.addRPath(dylib.getEmittedBinDirectory());
     exe.dead_strip_dylibs = true;
 
     const check = exe.checkObject();

test/link/macho/search_strategy/build.zig

@@ -57,10 +57,6 @@ fn createScenario(
     });
     static.addCSourceFile(.{ .file = .{ .path = "a.c" }, .flags = &.{} });
     static.linkLibC();
-    static.override_dest_dir = std.Build.InstallDir{
-        .custom = "static",
-    };
-    static.forceEmit(.bin);
 
     const dylib = b.addSharedLibrary(.{
         .name = name,
@@ -70,10 +66,6 @@ fn createScenario(
     });
     dylib.addCSourceFile(.{ .file = .{ .path = "a.c" }, .flags = &.{} });
     dylib.linkLibC();
-    dylib.override_dest_dir = std.Build.InstallDir{
-        .custom = "dynamic",
-    };
-    dylib.forceEmit(.bin); // we want the binary to be built as we use it further below
 
     const exe = b.addExecutable(.{
         .name = name,
@@ -83,8 +75,8 @@ fn createScenario(
     exe.addCSourceFile(.{ .file = .{ .path = "main.c" }, .flags = &.{} });
     exe.linkSystemLibraryName(name);
     exe.linkLibC();
-    exe.addLibraryPath(static.getEmitDirectory());
+    exe.addLibraryPath(static.getEmittedBinDirectory());
-    exe.addLibraryPath(dylib.getEmitDirectory());
+    exe.addLibraryPath(dylib.getEmittedBinDirectory());
-    exe.addRPath(dylib.getEmitDirectory());
+    exe.addRPath(dylib.getEmittedBinDirectory());
     return exe;
 }

test/link/macho/tbdv3/build.zig

@@ -25,7 +25,6 @@ fn add(b: *std.Build, test_step: *std.Build.Step, optimize: std.builtin.Optimize
     });
     lib.addCSourceFile(.{ .file = .{ .path = "a.c" }, .flags = &.{} });
     lib.linkLibC();
-    lib.forceEmit(.bin); // will be referenced by the tbd file
 
     const tbd_file = b.addWriteFile("liba.tbd",
         \\--- !tapi-tbd-v3
@@ -47,7 +46,7 @@ fn add(b: *std.Build, test_step: *std.Build.Step, optimize: std.builtin.Optimize
     exe.addCSourceFile(.{ .file = .{ .path = "main.c" }, .flags = &[0][]const u8{} });
     exe.linkSystemLibrary("a");
     exe.addLibraryPath(tbd_file.getDirectory());
-    exe.addRPath(lib.getEmitDirectory());
+    exe.addRPath(lib.getEmittedBinDirectory());
     exe.linkLibC();
 
     const run = b.addRunArtifact(exe);

test/link/macho/weak_library/build.zig

@@ -33,8 +33,8 @@ fn add(b: *std.Build, test_step: *std.Build.Step, optimize: std.builtin.Optimize
     exe.addCSourceFile(.{ .file = .{ .path = "main.c" }, .flags = &[0][]const u8{} });
     exe.linkLibC();
     exe.linkSystemLibraryWeak("a");
-    exe.addLibraryPath(dylib.getEmitDirectory());
+    exe.addLibraryPath(dylib.getEmittedBinDirectory());
-    exe.addRPath(dylib.getEmitDirectory());
+    exe.addRPath(dylib.getEmittedBinDirectory());
 
     const check = exe.checkObject();
     check.checkStart();

test/src/Cases.zig

@@ -551,12 +551,6 @@ pub fn lowerToBuildSteps(
             }),
         };
 
-        if (case.emit_bin) {
-            artifact.forceEmit(.bin);
-        } else {
-            artifact.forceBuild();
-        }
-
         if (case.link_libc) artifact.linkLibC();
 
         switch (case.backend) {

test/standalone/compiler_rt_panic/build.zig

@@ -16,7 +16,10 @@ pub fn build(b: *std.Build) void {
         .target = target,
     });
     exe.linkLibC();
-    exe.addCSourceFile("main.c", &.{});
+    exe.addCSourceFile(.{
+        .file = .{ .path = "main.c" },
+        .flags = &.{},
+    });
     exe.link_gc_sections = false;
     exe.bundle_compiler_rt = true;
 

test/standalone/embed_generated_file/build.zig

@@ -22,7 +22,8 @@ pub fn build(b: *std.Build) void {
         .source_file = bootloader.getEmittedBin(),
     });
 
-    exe.forceBuild();
+    // TODO: actually check the output
+    _ = exe.getEmittedBin();
 
     test_step.dependOn(&exe.step);
 }

test/standalone/emit_asm_and_bin/build.zig

@@ -8,8 +8,9 @@ pub fn build(b: *std.Build) void {
         .root_source_file = .{ .path = "main.zig" },
         .optimize = b.standardOptimizeOption(.{}),
     });
-    main.forceEmit(.bin);
+    // TODO: actually check these two artifacts for correctness
-    main.forceEmit(.@"asm");
+    _ = main.getEmittedBin();
+    _ = main.getEmittedAsm();
 
     test_step.dependOn(&b.addRunArtifact(main).step);
 }

test/standalone/issue_339/build.zig

@@ -14,7 +14,8 @@ pub fn build(b: *std.Build) void {
         .optimize = optimize,
     });
 
-    obj.forceBuild();
+    // TODO: actually check the output
+    _ = obj.getEmittedBin();
 
     test_step.dependOn(&obj.step);
 }

test/standalone/issue_5825/build.zig

@@ -27,7 +27,8 @@ pub fn build(b: *std.Build) void {
     exe.linkSystemLibrary("ntdll");
     exe.addObject(obj);
 
-    exe.forceBuild();
+    // TODO: actually check the output
+    _ = exe.getEmittedBin();
 
     test_step.dependOn(&exe.step);
 }

test/standalone/issue_794/build.zig

@@ -9,7 +9,8 @@ pub fn build(b: *std.Build) void {
     });
     test_artifact.addIncludePath(.{ .path = "a_directory" });
 
-    test_artifact.forceBuild();
+    // TODO: actually check the output
+    _ = test_artifact.getEmittedBin();
 
     test_step.dependOn(&test_artifact.step);
 }

test/standalone/main_pkg_path/build.zig

@@ -6,8 +6,8 @@ pub fn build(b: *std.Build) void {
 
     const test_exe = b.addTest(.{
         .root_source_file = .{ .path = "a/test.zig" },
+        .main_pkg_path = .{ .path = "." },
     });
-    test_exe.setMainPkgPath(.{ .path = "." });
 
     test_step.dependOn(&b.addRunArtifact(test_exe).step);
 }

test/standalone/strip_empty_loop/build.zig

@@ -15,7 +15,8 @@ pub fn build(b: *std.Build) void {
     });
     main.strip = true;
 
-    main.forceBuild();
+    // TODO: actually check the output
+    _ = main.getEmittedBin();
 
     test_step.dependOn(&main.step);
 }

test/tests.zig

@@ -588,7 +588,7 @@ pub fn addStandaloneTests(
                 });
                 if (case.link_libc) exe.linkLibC();
 
-                exe.forceBuild();
+                _ = exe.getEmittedBin();
 
                 step.dependOn(&exe.step);
             }
@@ -1008,6 +1008,7 @@ pub fn addModuleTests(b: *std.Build, options: ModuleTestOptions) *Step {
             .single_threaded = test_target.single_threaded,
             .use_llvm = test_target.use_llvm,
             .use_lld = test_target.use_lld,
+            .zig_lib_dir = .{ .path = "lib" },
         });
         const single_threaded_suffix = if (test_target.single_threaded == true) "-single" else "";
         const backend_suffix = if (test_target.use_llvm == true)
@@ -1019,7 +1020,6 @@ pub fn addModuleTests(b: *std.Build, options: ModuleTestOptions) *Step {
         else
             "";
 
-        these_tests.overrideZigLibDir(.{ .path = "lib" });
         these_tests.addIncludePath(.{ .path = "test" });
 
         const qualified_name = b.fmt("{s}-{s}-{s}{s}{s}{s}", .{
@@ -1039,8 +1039,8 @@ pub fn addModuleTests(b: *std.Build, options: ModuleTestOptions) *Step {
                 .name = qualified_name,
                 .link_libc = test_target.link_libc,
                 .target = altered_target,
+                .zig_lib_dir = .{ .path = "lib" },
             });
-            compile_c.overrideZigLibDir(.{ .path = "lib" });
             compile_c.addCSourceFile(.{
                 .file = these_tests.getEmittedBin(),
                 .flags = &.{