Make first_ids_file an optional attribute of the .grd file.

grit/tool/build.py

Index: grit/tool/build.py
===================================================================
--- grit/tool/build.py	(revision 18)
+++ grit/tool/build.py	(working copy)
@@ -56,10 +56,10 @@
 
   -E NAME=VALUE     Set environment variable NAME to VALUE (within grit).
 
-  -f FIRSTIDFILE    Path to a python file that specifies the first id of
-                    value to use for resources.  Defaults to the file
-                    resources_ids next to grit.py.  Set to an empty string
-                    if you don't want to use a first id file.
+  -f FIRSTIDSFILE   Path to a python file that specifies the first id of
+                    value to use for resources.  A non-empty value here will
+                    override the value specified in the <grit> node's
+                    first_ids_file.
 
   -w WHITELISTFILE  Path to a file containing the string names of the
                     resources to include.  Anything not listed is dropped.
@@ -77,7 +77,7 @@
 
   def Run(self, opts, args):
     self.output_directory = '.'
-    first_id_filename = None
+    first_ids_file = None
     whitelist_filenames = []
     (own_opts, args) = getopt.getopt(args, 'o:D:E:f:w:')
     for (key, val) in own_opts:
@@ -90,7 +90,10 @@
         (env_name, env_value) = val.split('=')
         os.environ[env_name] = env_value
       elif key == '-f':
-        first_id_filename = val
+        # TODO(joi@chromium.org): Remove this override once change
+        # lands in WebKit.grd to specify the first_ids_file in the
+        # .grd itself.

[tony, 2012/03/28 17:31:56]

I like the command line flag. In Chromium, if someone adds a new grd file, I
want it to warn that they need to pick an ID. If grit_action.gypi uses the -f
flag, new .grd files should get this warning automatically.  If we use
attributes, it's easier for someone to forget.

[Jói, 2012/03/29 11:36:15]

I'd prefer to have just one way to do things, but for now the flag stays and we
can talk before I make further changes.

My plan was to add a presubmit check to Chrome to verify that any .grd file
being modified has the attribute.  What would you say to that approach?  This is
perhaps even more foolproof than the flag, since it would catch somebody adding
a new .grd file that gets built by a customized invocation of grit rather than
using grit_action.gypi.

+        first_ids_file = val
       elif key == '-w':
         whitelist_filenames.append(val)
 
@@ -113,8 +116,10 @@
         self.whitelist_names |= set(whitelist_file.read().strip().split('\n'))
         whitelist_file.close()
 
-    self.res = grd_reader.Parse(opts.input, first_id_filename=first_id_filename,
-                                debug=opts.extra_verbose, defines=self.defines)
+    self.res = grd_reader.Parse(opts.input,
+                                debug=opts.extra_verbose,
+                                first_ids_file=first_ids_file,
+                                defines=self.defines)
     self.res.RunGatherers(recursive = True)
     self.Process()
     return 0