Improve toolchain integration

build.zig

@@ -40,8 +40,18 @@ pub fn build(b: *Build) !void {
     // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
     const mode = b.standardOptimizeOption(.{});
 
+    const default_path_sep: u8 = if (target.isWindows()) ';' else ':';
+
+    const enable_linker_build_id = b.option(bool, "enable-linker-build-id", "pass --build-id to linker") orelse false;
+    const default_linker = b.option([]const u8, "default-linker", "Default linker aro will use if none is supplied via -fuse-ld") orelse "ld";
+    const default_sysroot = b.option([]const u8, "default-sysroot", "Default <path> to all compiler invocations for --sysroot=<path>.") orelse "";
+    const gcc_install_prefix = b.option([]const u8, "gcc-install-prefix", "Directory where gcc is installed.") orelse "";
+    const default_rtlib = b.option([]const u8, "default-rtlib", "Default compiler runtime library if --rtlib is not specified") orelse "";
+    const default_unwindlib = b.option([]const u8, "default-unwindlib", "Default unwind library to use (\"none\" \"libgcc\" or \"libunwind\", empty to match runtime library.)") orelse
+        if (std.mem.eql(u8, default_rtlib, "libgcc")) "libgcc" else "";
     const test_all_allocation_failures = b.option(bool, "test-all-allocation-failures", "Test all allocation failures") orelse false;
     const link_libc = b.option(bool, "link-libc", "Force self-hosted compiler to link libc") orelse (mode != .Debug);
+    const path_sep = b.option(u8, "path-sep", "Path separator in PATH environment variable") orelse default_path_sep;
     const tracy = b.option([]const u8, "tracy", "Enable Tracy integration. Supply path to Tracy source");
     const tracy_callstack = b.option(bool, "tracy-callstack", "Include callstack information with Tracy data. Does nothing if -Dtracy is not provided") orelse false;
     const tracy_allocation = b.option(bool, "tracy-allocation", "Include allocation information with Tracy data. Does nothing if -Dtracy is not provided") orelse false;
@@ -65,6 +75,18 @@ pub fn build(b: *Build) !void {
     });
     const exe_options = b.addOptions();
     exe.addOptions("build_options", exe_options);
+
+    const system_defaults = b.addOptions();
+    exe.addOptions("system_defaults", system_defaults);
+
+    system_defaults.addOption(bool, "enable_linker_build_id", enable_linker_build_id);
+    system_defaults.addOption([]const u8, "linker", default_linker);
+    system_defaults.addOption(u8, "path_sep", path_sep);
+    system_defaults.addOption([]const u8, "sysroot", default_sysroot);
+    system_defaults.addOption([]const u8, "gcc_install_prefix", gcc_install_prefix);
+    system_defaults.addOption([]const u8, "rtlib", default_rtlib);
+    system_defaults.addOption([]const u8, "unwindlib", default_unwindlib);
+
     exe_options.addOption(bool, "enable_tracy", tracy != null);
     exe_options.addOption(bool, "enable_tracy_callstack", tracy_callstack);
     exe_options.addOption(bool, "enable_tracy_allocation", tracy_allocation);
@@ -101,6 +123,7 @@ pub fn build(b: *Build) !void {
 
     var unit_tests = b.addTest(.{ .root_source_file = .{ .path = "src/main.zig" } });
     unit_tests.addModule("zig", zig_module);
+    unit_tests.addOptions("system_defaults", system_defaults);
     const run_test = b.addRunArtifact(unit_tests);
     tests_step.dependOn(&run_test.step);
 
@@ -111,6 +134,7 @@ pub fn build(b: *Build) !void {
     integration_tests.addModule("aro", aro_module);
     const test_runner_options = b.addOptions();
     integration_tests.addOptions("build_options", test_runner_options);
+    integration_tests.addOptions("system_defaults", system_defaults);
     test_runner_options.addOption(bool, "test_all_allocation_failures", test_all_allocation_failures);
 
     const integration_test_runner = b.addRunArtifact(integration_tests);

src/Compilation.zig

@@ -31,6 +31,9 @@ pub const Environment = struct {
     /// TODO: not implemented yet
     tmpdir: ?[]const u8 = null,
 
+    /// PATH environment variable used to search for programs
+    path: ?[]const u8 = null,
+
     /// Directories to try when searching for subprograms.
     /// TODO: not implemented yet
     compiler_path: ?[]const u8 = null,
@@ -901,9 +904,9 @@ pub fn getCharSignedness(comp: *const Compilation) std.builtin.Signedness {
     return comp.langopts.char_signedness_override orelse comp.target.charSignedness();
 }
 
-pub fn defineSystemIncludes(comp: *Compilation) !void {
+pub fn defineSystemIncludes(comp: *Compilation, aro_dir: []const u8) !void {
     var buf: [std.fs.MAX_PATH_BYTES]u8 = undefined;
-    var search_path: []const u8 = std.fs.selfExePath(&buf) catch return error.SelfExeNotFound;
+    var search_path = aro_dir;
     while (std.fs.path.dirname(search_path)) |dirname| : (search_path = dirname) {
         var base_dir = std.fs.cwd().openDir(dirname, .{}) catch continue;
         defer base_dir.close();

src/Diagnostics.zig

@@ -165,6 +165,7 @@ pub const Options = packed struct {
     @"gnu-auto-type": Kind = .default,
     @"gnu-union-cast": Kind = .default,
     @"pointer-sign": Kind = .default,
+    @"fuse-ld-path": Kind = .default,
 };
 
 const messages = struct {
@@ -2351,6 +2352,30 @@ const messages = struct {
         const msg = "environment variable SOURCE_DATE_EPOCH must expand to a non-negative integer less than or equal to 253402300799";
         const kind = .@"error";
     };
+    pub const fuse_ld_path = struct {
+        const msg = "'-fuse-ld=' taking a path is deprecated; use '--ld-path=' instead";
+        const kind = .off;
+        const opt = "fuse-ld-path";
+    };
+    pub const invalid_rtlib = struct {
+        const msg = "invalid runtime library name '{s}'";
+        const kind = .@"error";
+        const extra = .str;
+    };
+    pub const unsupported_rtlib_gcc = struct {
+        const msg = "unsupported runtime library 'libgcc' for platform '{s}'";
+        const kind = .@"error";
+        const extra = .str;
+    };
+    pub const invalid_unwindlib = struct {
+        const msg = "invalid unwind library name '{s}'";
+        const kind = .@"error";
+        const extra = .str;
+    };
+    pub const incompatible_unwindlib = struct {
+        const msg = "--rtlib=libgcc requires --unwindlib=libgcc";
+        const kind = .@"error";
+    };
 };
 
 list: std.ArrayListUnmanaged(Message) = .{},