Add malioc runner script

build/gn_run_malioc.py

@@ -0,0 +1,54 @@
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Helper script for GN to run malioc.
+
+This is the same as `gn_run_binary.py`, except an extra parameter is included
+for the malioc output file. When the malioc run fails, errors are placed in the
+json output file. This script attempts to read the output file and dump it to
+stdout upon failure.
+
+Run with:
+  python gn_run_malioc.py <binary_name> <output_path> [args ...]
+"""
+
+import json
+import os
+import sys
+import subprocess
+
+# This script is designed to run binaries produced by the current build. We
+# always prefix it with "./" to avoid picking up system versions that might
+# also be on the path.
+path = './' + sys.argv[1]
+
+malioc_output = sys.argv[2]
+
+# The rest of the arguements are passed directly to the executable.
+args = [path, '--output', malioc_output] + sys.argv[3:]
+
+try:
+  subprocess.check_output(args, stderr=subprocess.STDOUT)
+except subprocess.CalledProcessError as ex:
+  print(ex.output.decode('utf-8', errors='replace'))
+  if os.path.exists(malioc_output):
+    with open(malioc_output, 'r') as malioc_file:
+      malioc_json = malioc_file.read()
+
+    print('malioc output:')
+    # Attempt to pretty print the json output, but fall back to printing the
+    # raw output if doing so fails.
+    try:
+      parsed = json.load(malioc_json)
+      print(json.dumps(parsed, indent=2))
+    except:
+      print(malioc_json)
+
+  else:
+    print(
+        'Unable to find the malioc output file in order to print contained'
+        'errors:',
+        malioc_output,
+    )
+  sys.exit(ex.returncode)