feat: add support for global zigopt setting

zig/private/settings.bzl

@@ -27,6 +27,18 @@ ATTRS = {
         doc = "The Zig multi- or single-threaded setting.",
         mandatory = True,
     ),
+    "zigopt": attr.label(
+        doc = """
+Additional list of flags passed to the zig compiler for all Zig compile actions.
+
+The flags specified by this setting do not override those specified via the `zigopts` attribute of `zig_*` rules.
+Instead, they are prepended to the command line before module specific flags.
+
+This is an advanced feature that can conflict with attributes, build settings, and other flags defined by the toolchain itself.
+Use this at your own risk of hitting undefined behaviors.
+""",
+        mandatory = True,
+    ),
 }
 
 MODE_ARGS = {
@@ -56,6 +68,9 @@ def _settings_impl(ctx):
     threaded = ctx.attr.threaded[BuildSettingInfo].value
     args.extend(THREADED_ARGS[threaded])
 
+    zigopts = ctx.attr.zigopt[BuildSettingInfo].value
+    args.extend(zigopts)
+
     settings_info = ZigSettingsInfo(
         mode = mode,
         threaded = threaded,

zig/private/zig_configure.bzl

@@ -113,6 +113,8 @@ def _zig_transition_impl(settings, attr):
         result["//zig/settings:mode"] = attr.mode
     if attr.threaded:
         result["//zig/settings:threaded"] = attr.threaded
+    if attr.zigopt:
+        result["//zig/settings:zigopt"] = attr.zigopt
     return result
 
 _zig_transition = transition(
@@ -124,6 +126,7 @@ _zig_transition = transition(
         "//zig/settings:use_cc_common_link",
         "//zig/settings:mode",
         "//zig/settings:threaded",
+        "//zig/settings:zigopt",
     ],
     outputs = [
         "//command_line_option:extra_toolchains",
@@ -132,6 +135,7 @@ _zig_transition = transition(
         "//zig/settings:use_cc_common_link",
         "//zig/settings:mode",
         "//zig/settings:threaded",
+        "//zig/settings:zigopt",
     ],
 )
 
@@ -169,6 +173,18 @@ def _make_attrs(*, executable):
             mandatory = False,
             values = THREADED_VALUES,
         ),
+        "zigopt": attr.string_list(
+            doc = """
+Additional list of flags passed to the zig compiler for all Zig compile actions.
+
+The flags specified by this setting do not override those specified via the `zigopts` attribute of `zig_*` rules.
+Instead, they are prepended to the command line before module specific flags.
+
+This is an advanced feature that can conflict with attributes, build settings, and other flags defined by the toolchain itself.
+Use this at your own risk of hitting undefined behaviors.
+""",
+            mandatory = False,
+        ),
         "_allowlist_function_transition": attr.label(
             default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
         ),

zig/settings/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@bazel_skylib//rules:common_settings.bzl", "bool_flag", "string_flag")
+load("@bazel_skylib//rules:common_settings.bzl", "bool_flag", "repeatable_string_flag", "string_flag")
 load(
     "//zig/private:settings.bzl",
     "MODE_VALUES",
@@ -12,12 +12,13 @@ settings(
     threaded = ":threaded",
     use_cc_common_link = ":use_cc_common_link",
     visibility = ["//visibility:public"],
+    zigopt = ":zigopt",
 )
 
 bool_flag(
     name = "use_cc_common_link",
     build_setting_default = False,
-    visibility = ["//zig/config/mode:__pkg__"],
+    visibility = ["//visibility:private"],
 )
 
 string_flag(
@@ -34,6 +35,12 @@ string_flag(
     visibility = ["//zig/config/threaded:__pkg__"],
 )
 
+repeatable_string_flag(
+    name = "zigopt",
+    build_setting_default = [],
+    visibility = ["//visibility:private"],
+)
+
 # Execute `bazel run //util:update_filegroups` to update this target.
 filegroup(
     name = "all_files",

zig/tests/BUILD.bazel

@@ -12,6 +12,7 @@ load(":threaded_test.bzl", "threaded_test_suite")
 load(":toolchain_header_test.bzl", "toolchain_header_test_suite")
 load(":use_cc_common_link_test.bzl", "use_cc_common_link_test_suite")
 load(":versions_test.bzl", "versions_test_suite")
+load(":zigopt_test.bzl", "zigopt_test_suite")
 
 bzlmod_zig_test_suite(name = "bzlmod_zig_test")
 
@@ -39,6 +40,8 @@ toolchain_header_test_suite(name = "toolchain_header_test")
 
 versions_test_suite(name = "versions_test")
 
+zigopt_test_suite(name = "zigopt_test")
+
 bzl_library(
     name = "util",
     srcs = ["util.bzl"],

zig/tests/zigopt_test.bzl

@@ -0,0 +1,70 @@
+"""Analysis tests for Zig multi- or single-zigopt settings."""
+
+load("@bazel_skylib//lib:partial.bzl", "partial")
+load("@bazel_skylib//lib:unittest.bzl", "analysistest", "unittest")
+load("//zig/private/providers:zig_settings_info.bzl", "ZigSettingsInfo")
+load(
+    ":util.bzl",
+    "assert_find_action",
+    "assert_flag_set",
+    "canonical_label",
+)
+
+_SETTINGS_ZIGOPT = canonical_label("@//zig/settings:zigopt")
+
+def _define_settings_zigopt_test(zigopts):
+    def _test_impl(ctx):
+        env = analysistest.begin(ctx)
+
+        settings = analysistest.target_under_test(env)[ZigSettingsInfo]
+
+        for zigopt in zigopts:
+            assert_flag_set(env, zigopt, settings.args)
+
+        return analysistest.end(env)
+
+    return analysistest.make(
+        _test_impl,
+        config_settings = {_SETTINGS_ZIGOPT: zigopts},
+    )
+
+_settings_zigopt_test = _define_settings_zigopt_test(["-mcpu=native", "-flto"])
+
+def _define_build_zigopt_test(mnemonic, zigopts):
+    def _test_impl(ctx):
+        env = analysistest.begin(ctx)
+
+        action = assert_find_action(env, mnemonic)
+
+        for zigopt in zigopts:
+            assert_flag_set(env, zigopt, action.argv)
+
+        return analysistest.end(env)
+
+    return analysistest.make(
+        _test_impl,
+        config_settings = {_SETTINGS_ZIGOPT: zigopts},
+    )
+
+_build_exe_zigopt_test = _define_build_zigopt_test("ZigBuildExe", ["-mcpu-native", "-flto"])
+
+_build_static_lib_zigopt_test = _define_build_zigopt_test("ZigBuildStaticLib", ["-mcpu-native", "-flto"])
+
+_build_shared_lib_zigopt_test = _define_build_zigopt_test("ZigBuildSharedLib", ["-mcpu-native", "-flto"])
+
+_build_test_zigopt_test = _define_build_zigopt_test("ZigBuildTest", ["-mcpu-native", "-flto"])
+
+def zigopt_test_suite(name):
+    unittest.suite(
+        name,
+        # Test Zig zigopt setting on the settings target
+        partial.make(_settings_zigopt_test, target_under_test = "//zig/settings", size = "small"),
+        # Test Zig zigopt setting on a binary target
+        partial.make(_build_exe_zigopt_test, target_under_test = "//zig/tests/simple-binary:binary", size = "small"),
+        # Test Zig zigopt setting on a library target
+        partial.make(_build_static_lib_zigopt_test, target_under_test = "//zig/tests/simple-library:library", size = "small"),
+        # Test Zig zigopt setting on a shared library target
+        partial.make(_build_shared_lib_zigopt_test, target_under_test = "//zig/tests/simple-shared-library:shared", size = "small"),
+        # Test Zig zigopt setting on a test target
+        partial.make(_build_test_zigopt_test, target_under_test = "//zig/tests/simple-test:test", size = "small"),
+    )