add support for m1 llvm based on llvm 15

platforms/BUILD.bazel

@@ -37,3 +37,11 @@ platform(
         "@platforms//cpu:x86_64",
     ],
 )
+
+platform(
+    name = "darwin-aarch64",
+    constraint_values = [
+        "@platforms//os:osx",
+        "@platforms//cpu:aarch64",
+    ],
+)

toolchain/cc_toolchain_config.bzl

@@ -69,6 +69,15 @@ def cc_toolchain_config(
             "darwin_x86_64",
             "darwin_x86_64",
         ),
+        "darwin-aarch64": (
+            "clang-aarch64-darwin",
+            "aarch64-apple-macosx",
+            "darwin",
+            "macosx",
+            "clang",
+            "darwin_aarch64",
+            "darwin_aarch64",
+        ),
         "linux-aarch64": (
             "clang-aarch64-linux",
             "aarch64-unknown-linux-gnu",

toolchain/internal/common.bzl

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-SUPPORTED_TARGETS = [("linux", "x86_64"), ("linux", "aarch64"), ("darwin", "x86_64")]
+SUPPORTED_TARGETS = [("linux", "x86_64"), ("linux", "aarch64"), ("darwin", "x86_64"), ("darwin", "aarch64")]
 
 host_tool_features = struct(
     SUPPORTS_ARG_FILE = "supports_arg_file",
@@ -68,7 +68,10 @@ def arch(rctx):
     ])
     if exec_result.return_code:
         fail("Failed to detect machine architecture: \n%s\n%s" % (exec_result.stdout, exec_result.stderr))
-    return exec_result.stdout.strip()
+    arch = exec_result.stdout.strip()
+    if arch == "arm64":
+        return "aarch64"
+    return arch
 
 def os_arch_pair(os, arch):
     return "{}-{}".format(os, arch)

toolchain/tools/llvm_release_name.py

@@ -28,9 +28,17 @@ def _minor_llvm_version(llvm_version):
 def _patch_llvm_version(llvm_version):
     return int(llvm_version.split(".")[2])
 
+def _darwin_apple_suffix(major_llvm_version, arch):
+    if major_llvm_version == 9:
+        "darwin-apple"
+    elif arch == "arm64":
+        return "apple-darwin21.0"
+    else:
+        return "apple-darwin"
+
 def _darwin(llvm_version, arch):
     major_llvm_version = _major_llvm_version(llvm_version)
-    suffix = "darwin-apple" if major_llvm_version == 9 else "apple-darwin"
+    suffix = _darwin_apple_suffix(major_llvm_version, arch)
     return "clang+llvm-{llvm_version}-{arch}-{suffix}.tar.xz".format(
         llvm_version=llvm_version, arch=arch, suffix=suffix)