Add mold integration (#13)

.bazelrc

@@ -1 +1,4 @@
+# TODO: Remove once mold supports -S
+build --strip=never
+
 test --test_output=errors

BUILD

@@ -1,4 +1,4 @@
-load("@rules_apple_linker//:rules.bzl", "lld_override", "zld_override")
+load("@rules_apple_linker//:rules.bzl", "lld_override", "mold_override", "zld_override")
 
 zld_override(
     name = "zld",
@@ -9,3 +9,8 @@ lld_override(
     name = "lld",
     visibility = ["//visibility:public"],
 )
+
+mold_override(
+    name = "mold",
+    visibility = ["//visibility:public"],
+)

deps.bzl

@@ -18,3 +18,10 @@ def rules_apple_linker_deps():
         sha256 = "28566b943082349269b6460a5c23a305a73460bac54f5cd21eb490ff7d84fed7",
         url = "https://github.com/keith/ld64.lld/releases/download/10-14-22/ld64.tar.xz",
     )
+
+    http_archive(
+        name = "rules_apple_linker_mold",
+        build_file_content = 'filegroup(name = "mold_bin", srcs = ["ld64.mold"], visibility = ["//visibility:public"])',
+        sha256 = "2b1ab27d4ab0d6319cf79b6bc94710e8a515c069670191dea022c3dffaef64fd",
+        url = "https://github.com/keith/ld64.mold/releases/download/11-7-22/ld64.tar.xz",
+    )

rules.bzl

@@ -121,3 +121,20 @@ lld_override = rule(
     ),
     provides = [apple_common.Objc, CcInfo],
 )
+
+def _mold_override(ctx):
+    return _linker_override(ctx, ctx.attr.mold_linkopts)
+
+mold_override = rule(
+    implementation = _mold_override,
+    attrs = _attrs(
+        "@rules_apple_linker_mold//:mold_bin",
+        {
+            "mold_linkopts": attr.string_list(
+                mandatory = False,
+                doc = "The options to pass to mold, and not ld64 (see enable)",
+            ),
+        },
+    ),
+    provides = [apple_common.Objc, CcInfo],
+)

test/BUILD

@@ -52,6 +52,15 @@ cc_test(
     deps = ["@rules_apple_linker//:zld"],
 )
 
+cc_test(
+    name = "mold_test",
+    srcs = ["main.c"],
+    features = [
+        "-dynamic_linking_mode",  # TODO: https://github.com/bazelbuild/bazel/pull/16414
+    ],
+    deps = ["@rules_apple_linker//:mold"],
+)
+
 cc_library(
     name = "binary_lib",
     srcs = ["main.c"],
@@ -158,7 +167,15 @@ action_command_line_test(
     mnemonics = ["CppLink"],
     not_expected_argv = [
         "--ld-path=external/rules_apple_linker_lld/ld64.lld",
+        "--ld-path=external/rules_apple_linker_mold/ld64.mold",
         "--ld-path=external/rules_apple_linker_zld/zld",
     ],
     target_under_test = ":default_test",
 )
+
+action_command_line_test(
+    name = "use_mold_test",
+    expected_argv = ["--ld-path=external/rules_apple_linker_mold/ld64.mold"],
+    mnemonics = ["CppLink"],
+    target_under_test = ":mold_test",
+)