- Remove unneeded library tags when concatenating libraries.

runtime/tools/concat_library.py

 #!/usr/bin/env python
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 import optparse
 import shutil
 import sys
 
 def parse_options(argv):
@@ skipping 13 matching lines @@
 def main():
     # Print the command that is being run. This is helpful when
     # debugging build errors.
     sys.stderr.write('%s\n' % ' '.join(sys.argv))
     (options, arguments) = parse_options(sys.argv)
     tmp_name = '%s.tmp' % options.output
     with open(tmp_name, 'w') as output:
         for source in arguments:
             with open(source, 'r') as inpt:
                 for line in inpt:
-                    if line.startswith('#source'):
+                    # Drop unneeded library tags as all the library's files
+                    # are concatenated into one big file here:
+                    # The 'part' and 'part of' library tags are removed.
+                    if line.startswith('#source') or line.startswith('part '):

[siva, 2012/11/27 02:18:07]

There is the danger of legal lines which start with part being removed here:
e.g:
func1(
param1 ,
part ,
sum);

Also, is it a requirement that 'part' has to be the first word without any
whitespace?
e.g:
   part of deepshit;  // Is this legal.

why not do:
line = re.sub("part of .*;", "", line);

[Ivan Posva, 2012/11/27 05:38:19]

I understand all of these limitations (they went away with the new syntax which
is easier on the eyes and harder for tools). In any case we also need to replace
the equivalent of #source, which is "part 'uri';" so this hits two birds with
one stone. Eventually this should go away when we load the sources directly from
disk for dart_no_snapshot and gen_snapshot. We still will need to find a way to
load the non-snapshotted sources at that point though.

Somebody with better regular expression understanding than me can certainly
refine the above test. Currently it seems to be safe.

                         line = '// %s' % line
                     output.write(line)
     shutil.move(tmp_name, options.output)
 
 if __name__ == '__main__':
     main()