Bug 1914947 - Build Intel mac clang on arm64 workers. r=firefox-build-system-reviewers,sergesanspaille

That's actually much faster.

Differential Revision: https://phabricator.services.mozilla.com/D220531

build/build-clang/build-clang.py

@@ -180,7 +180,16 @@ def is_windows(target):
 
 
 def is_cross_compile(target):
-    return SUPPORTED_TARGETS[target] != (platform.system(), platform.machine())
+    target_system, target_machine = SUPPORTED_TARGETS[target]
+    system, machine = (platform.system(), platform.machine())
+    if system != target_system:
+        return True
+    # Don't consider x86 mac on arm64 mac a cross-compile so that we
+    # can build x86 mac clang on arm64 mac via Rosetta, as if they
+    # were building on x86.
+    if system == "Darwin" and machine == "arm64":
+        return False
+    return machine != target_machine
 
 
 def build_one_stage(

taskcluster/kinds/toolchain/clang.yml

@@ -304,9 +304,9 @@ macosx64-clang-18-profile:
     description: "Clang 18 toolchain build"
     treeherder:
         symbol: TM(clang-18-profile)
-    worker-type: b-osx-1015
+    worker-type: b-osx-arm64
     worker:
-        max-run-time: 14400
+        max-run-time: 7200
     run:
         using: toolchain-script
         script: build-clang.sh
@@ -899,9 +899,9 @@ macosx64-clang-trunk-profile:
         cached_task: false
     treeherder:
         symbol: TM(clang-trunk-profile)
-    worker-type: b-osx-1015
+    worker-type: b-osx-arm64
     worker:
-        max-run-time: 14400
+        max-run-time: 7200
     run:
         using: toolchain-script
         script: build-clang.sh