clang-format: use llvm binary on linux [BUILD-640] (#57)

Makes the `clang_format` rule hermetic on linux by using the clang-format binary that is provided with the llvm distribution instead of the system version.

This will remove any discrepancy between local dev and ci.

The select condition will be removed once we've set up the llvm toolchain on macos.

Author: jungleraptor

cc/toolchains/llvm.BUILD.bzl

@@ -130,3 +130,8 @@ filegroup(
     name = "clang-tidy",
     srcs = ["bin/clang-tidy"],
 )
+
+filegroup(
+    name = "clang-format",
+    srcs = ["bin/clang-format"],
+)

clang_format/BUILD renamed to clang_format/BUILD.bazel

@@ -18,7 +18,11 @@ choose_clang_format(
 
 filegroup(
     name = "_clang_format_bin",
-    srcs = [":clang_format_bin"],
+    srcs = select({
+        "@platforms//os:linux": ["@llvm-distribution//:clang-format"],
+        "//conditions:default": [":clang_format_bin"],
+    }),
+    visibility = ["//visibility:public"],
 )
 
 sh_binary(

clang_format/clang_format_check.bzl

@@ -56,6 +56,6 @@ clang_format_check_aspect = aspect(
     attrs = {
         "_clang_format": attr.label(default = Label("//clang_format:clang_format")),
         "_clang_format_config": attr.label(default = "//clang_format:clang_format_config"),
-        "_clang_format_bin": attr.label(default = Label("//clang_format:clang_format_bin")),
+        "_clang_format_bin": attr.label(default = Label("//clang_format:_clang_format_bin")),
     },
 )