[tools] gm.py: start goma when it isn't running

tools/dev/gm.py

 #!/usr/bin/env python
 # Copyright 2017 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.
 """\
 Convenience wrapper for compiling V8 with gn/ninja and running tests.
 Sets up build output directories if they don't exist.
 Produces simulator builds for non-Intel target architectures.
 Uses Goma by default if it is detected (at output directory setup time).
 Expects to be run from the root of a V8 checkout.
@@ skipping 62 matching lines @@
               "message": "d8",
               "mjsunit": "d8",
               "mozilla": "d8",
               "preparser": "d8",
               "test262": "d8",
               "unittests": "unittests",
               "webkit": "d8"}
 
 OUTDIR = "out"
 
-IS_GOMA_MACHINE = (os.path.exists(os.path.expanduser("~/goma")) or
-                   os.environ.get('GOMADIR'))
+def DetectGoma():
+  home_goma = os.path.expanduser("~/goma")
+  if os.path.exists(home_goma):
+    return home_goma
+  if os.environ.get("GOMADIR"):
+    return os.environ.get("GOMADIR")
+  return None
+
+GOMADIR = DetectGoma()
+IS_GOMA_MACHINE = GOMADIR is not None
 
 USE_GOMA = "true" if IS_GOMA_MACHINE else "false"
 BUILD_OPTS = BUILD_OPTS_GOMA if IS_GOMA_MACHINE else BUILD_OPTS_DEFAULT
 
 RELEASE_ARGS_TEMPLATE = """\
 is_component_build = false
 is_debug = false
 %s
 use_goma = {GOMA}
 v8_enable_backtrace = true
@@ skipping 184 matching lines @@
       self.ParseArg(argstring)
     self.ProcessGlobalActions()
     for c in self.configs:
       self.configs[c].Extend(self.global_targets, self.global_tests)
     return self.configs
 
 def Main(argv):
   parser = ArgumentParser()
   configs = parser.ParseArguments(argv[1:])
   return_code = 0
+  # If we have Goma but it is not running, start it.
+  if (GOMADIR is not None and
+      _Call("ps -e | grep compiler_proxy > /dev/null", silent=True) != 0):
+    _Call("%s/goma_ctl.py ensure_start" % GOMADIR)
   for c in configs:
     return_code += configs[c].Build()
   if return_code == 0:
     for c in configs:
       return_code += configs[c].RunTests()
   if return_code == 0:
     _Call("notify-send 'Done!' 'V8 compilation finished successfully.'",
           silent=True)
   else:
     _Call("notify-send 'Error!' 'V8 compilation finished with errors.'",
           silent=True)
   return return_code
 
 if __name__ == "__main__":
   sys.exit(Main(sys.argv))