For building v8 using gn on aix_ppc64, linux_s390x and linux_ppc64.

build/toolchain/gcc_ar_wrapper_aix.py

Index: build/toolchain/gcc_ar_wrapper_aix.py
diff --git a/build/toolchain/gcc_ar_wrapper_aix.py b/build/toolchain/gcc_ar_wrapper_aix.py
new file mode 100755
index 0000000000000000000000000000000000000000..5f47e2c36db67bd57bc28fff5a899f32cd09b865
--- /dev/null
+++ b/build/toolchain/gcc_ar_wrapper_aix.py
@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+# Copyright 2015 The Chromium Authors. All rights reserved.

[Michael Achenbach, 2017/04/18 13:46:04]

nit: 2017

+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Runs the 'ar' command after removing its output file first.
+
+This script is invoked like:
+  python gcc_ar_wrapper.py --ar=$AR --output=$OUT $OP $INPUTS
+to do the equivalent of:
+  rm -f $OUT && $AR $OP $OUT $INPUTS
+"""
+
+import argparse
+import os
+import subprocess
+import sys
+
+import wrapper_utils
+
+
+def main():
+  parser = argparse.ArgumentParser(description=__doc__)
+  parser.add_argument('--ar',
+                      required=True,
+                      help='The ar binary to run',
+                      metavar='PATH')
+  parser.add_argument('--output',
+                      required=True,
+                      help='Output archive file',
+                      metavar='ARCHIVE')
+  parser.add_argument('--plugin',
+                      help='Load plugin')
+  parser.add_argument('--resource-whitelist',

[Michael Achenbach, 2017/04/18 13:46:04]

nit: This is unused. Not sure if relevant. The original file does some stuff
with it. Though not really clear to me what:
https://cs.chromium.org/chromium/src/build/toolchain/gcc_ar_wrapper.py?q=gcc_...

These 3 lines are also the only difference between the new and the old file. any
chance you can modify the original to do what you want without breaking the old
code?

+                      help='Merge all resource whitelists into a single file.',
+                      metavar='PATH')
+  parser.add_argument('operation',
+                      help='Operation on the archive')
+  parser.add_argument('inputs', nargs='+',
+                      help='Input files')
+  args = parser.parse_args()
+
+# The @file feature is not avaliable on ar for AIX. For linux (and other posix
+# like systems), the @file_name option reads the contents of file_name as
+# command line arguments. For AIX we must parse these (rsp files) manually.
+# read rspfile.
+  parsed_as_command_line_inputs = wrapper_utils.ResolveRspLinks(args.inputs)
+  command = [args.ar, '-X64', args.operation]
+
+  if args.plugin is not None:
+    command += ['--plugin', args.plugin]
+  command.append(args.output)
+  command += parsed_as_command_line_inputs
+
+  # Remove the output file first.
+  try:
+    os.remove(args.output)
+  except OSError as e:
+    if e.errno != os.errno.ENOENT:
+      raise
+
+  # Now just run the ar command.
+  return subprocess.call(wrapper_utils.CommandToRun(command))
+
+
+if __name__ == "__main__":
+  sys.exit(main())