Re-enable running of closure compiler under java

.circleci/config.yml

@@ -919,10 +919,6 @@ jobs:
       - install-emsdk
       # TODO: We can't currently do pip install here since numpy and other packages
       # are currently missing arm64 macos binaries.
-      # TODO: Remove this once emsdk has an arm64 version of node
-      - run:
-          name: Install Rosetta
-          command: /usr/sbin/softwareupdate --install-rosetta --agree-to-license
       - run-tests:
           title: "crossplatform tests"
           test_targets: "--crossplatform-only"

tools/building.py

@@ -454,19 +454,25 @@ def get_closure_compiler():
   return cmd
 
 
-def check_closure_compiler(cmd, args, env):
+def check_closure_compiler(cmd, args, env, allowed_to_fail):
   cmd = cmd + args + ['--version']
   try:
     output = run_process(cmd, stdout=PIPE, env=env).stdout
   except Exception as e:
+    if allowed_to_fail:
+      return False
     if isinstance(e, subprocess.CalledProcessError):
       sys.stderr.write(e.stdout)
     sys.stderr.write(str(e) + '\n')
     exit_with_error('closure compiler (%s) did not execute properly!' % shared.shlex_join(cmd))
 
   if 'Version:' not in output:
+    if allowed_to_fail:
+      return False
     exit_with_error('unrecognized closure compiler --version output (%s):\n%s' % (shared.shlex_join(cmd), output))
 
+  return True
+
 
 # Remove this once we require python3.7 and can use std.isascii.
 # See: https://docs.python.org/3/library/stdtypes.html#str.isascii
@@ -482,7 +488,15 @@ def isascii(s):
 def get_closure_compiler_and_env(user_args):
   env = shared.env_with_node_in_path()
   closure_cmd = get_closure_compiler()
-  check_closure_compiler(closure_cmd, user_args, env)
+
+  native_closure_compiler_works = check_closure_compiler(closure_cmd, user_args, env, allowed_to_fail=True)
+  if not native_closure_compiler_works and not any(a.startswith('--platform') for a in user_args):
+    # Run with Java Closure compiler as a fallback if the native version does not work.
+    # This can happen, for example, on arm64 macOS machines that do not have Rosetta installed.
+    logger.warn('falling back to java version of closure compiler')
+    user_args.append('--platform=java')
+    check_closure_compiler(closure_cmd, user_args, env, allowed_to_fail=False)
+
   return closure_cmd, env