[Swarming] Isolate valgrind runner.

build/has_valgrind.py

Index: build/has_valgrind.py
diff --git a/build/has_valgrind.py b/build/has_valgrind.py
new file mode 100755
index 0000000000000000000000000000000000000000..4532b7a9ab79bbfa5597cdbb007be9325b524d19
--- /dev/null
+++ b/build/has_valgrind.py
@@ -0,0 +1,19 @@
+#!/usr/bin/env python
+# Copyright 2016 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+
+BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+VALGRIND_DIR = os.path.join(BASE_DIR, 'third_party', 'valgrind')
+LINUX32_DIR = os.path.join(VALGRIND_DIR, 'linux_x86')
+LINUX64_DIR = os.path.join(VALGRIND_DIR, 'linux_x64')
+

[kjellander_chromium, 2016/02/15 08:48:28]

two blank lines before top-level function

[Michael Achenbach, 2016/02/15 09:55:45]

Done.

+def DoMain(_):

[kjellander_chromium, 2016/02/15 08:48:28]

name this main(_): 
https://google.github.io/styleguide/pyguide.html?showone=Main#Main

[Michael Achenbach, 2016/02/15 09:55:45]

Won't work. This is not the python main function but a gyp hook. Gyp expects it
to be called like that and calls the function directly with the pymod_do_main
action in standalone.gypi. It is widely used
https://code.google.com/p/chromium/codesearch#search/&q=pymod_do_main&sq=pack...
and well documented as usual ;)

[kjellander_chromium, 2016/02/15 11:49:26]

Ah, I didn't pay attention to (or knew about) that. Sorry - I should have known
that you know how to name a main function ;)

+  """Hook to be called from gyp without starting a separate python
+  interpreter."""
+  return int(os.path.exists(LINUX32_DIR) and os.path.exists(LINUX64_DIR))
+

[kjellander_chromium, 2016/02/15 08:48:28]

+1 blank line

[Michael Achenbach, 2016/02/15 09:55:45]

Done.

+if __name__ == '__main__':
+  print DoMain([])