Add src/printing to the GN build.

printing/cups_config_helper.py

 #!/usr/bin/env python
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """cups-config wrapper.
 
 cups-config, at least on Ubuntu Lucid and Natty, dumps all
 cflags/ldflags/libs when passed the --libs argument.  gyp would like
 to keep these separate: cflags are only needed when compiling files
 that use cups directly, while libs are only needed on the final link
 line.
 
 TODO(evan): remove me once
   https://bugs.launchpad.net/ubuntu/+source/cupsys/+bug/163704

[Lei Zhang, 2014/06/02 22:37:02]

I just noticed this too. On my Linux machine, cups-config --libs outputs:

-lcups -L/usr/lib/x86_64-linux-gnu -Wl,-Bsymbolic-functions -Wl,-z,relro
-lgssapi_krb5 -lkrb5 -lk5crypto -lcom_err -lgnutls -L/lib/x86_64-linux-gnu
-lgcrypt -lz -lpthread -lcrypt -lm

which looks fairly sane, so maybe we can get rid of this file altogether as
well? Would that make the enabling GN for printing/ easier?

[brettw, 2014/06/02 22:53:26]

I actually need this for GN to get the libs the way I want (unless we want to
hardcode the list of dependencies, which I'm also OK doing). I need to strip the
"-l"s and format as a GN list.

[Lei Zhang, 2014/06/02 23:33:27]

Ok, I'll make a pass through this file later and clean it up a bit.

 is fixed.
 """
 
 import subprocess
 import sys
 
 def usage():
-  print 'usage: %s {--cflags|--ldflags|--libs}' % sys.argv[0]
+  print 'usage: %s {--api-version|--cflags|--ldflags|--libs|--libs-for-gn}' % \
+      sys.argv[0]
 
 
 def run_cups_config(mode):
   """Run cups-config with all --cflags etc modes, parse out the mode we want,
   and return those flags as a list."""
 
   cups = subprocess.Popen(['cups-config', '--cflags', '--ldflags', '--libs'],
                           stdout=subprocess.PIPE)
   flags = cups.communicate()[0].strip()
 
@@ skipping 19 matching lines @@
 
   return flags_subset
 
 
 def main():
   if len(sys.argv) != 2:
     usage()
     return 1
 
   mode = sys.argv[1]
-  if mode not in ('--cflags', '--libs', '--ldflags'):
+  if mode == '--api-version':
+    subprocess.call(['cups-config', '--api-version'])
+    return 0
+
+  # All other modes get the flags.
+  if mode not in ('--cflags', '--libs', '--libs-for-gn', '--ldflags'):
     usage()
     return 1
+
+  if mode == '--libs-for-gn':
+    gn_libs_output = True
+    mode = '--libs'
+  else:
+    gn_libs_output = False
+
   flags = run_cups_config(mode)
-  print ' '.join(flags)
+
+  if gn_libs_output:
+    # Strip "-l" from beginning of libs, quote, and surround in [ ].
+    print '['

[Lei Zhang, 2014/06/02 23:33:27]

We should sanity check and make sure |lib| starts with "-l".
run_cups_config('--libs') doesn't guarantee all the returned values in |flags|
start with '-l'.

Otherwise, this block could have been shortened to:

print '[\n%s\n]' % '\n'.join('"%s"' % lib[2:] for lib in flags)

+    for lib in flags:
+      print '"%s", ' % lib[2:]
+    print ']'
+  else:
+    print ' '.join(flags)
+
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())