[NaCl SDK] easy_template: fix bug when using % in an expression template.

native_client_sdk/src/build_tools/easy_template.py

 #!/usr/bin/env python
 # Copyright (c) 2013 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.
 
 import copy
 import cStringIO
 import optparse
 import os
 import re
@@ skipping 14 matching lines @@
       indent_string = indent_re.match(statement).group()
       if statement.rstrip()[-1:] == ':':
         indent_string += '  '
       output.write(statement + '\n')
     else:
       line_ending = ''
       while line and line[-1] in '\\"\n\r':
         line_ending = line[-1] + line_ending
         line = line[:-1]
 
-      m = expr_re.search(line)
-      if m:
-        line = line.replace('%', '%%')
+      ms = list(expr_re.finditer(line))
+      if ms:
+        # Only replace % with %% outside of the expr matches.
+        new_line = ''
+        start = 0
+        for m in ms:
+          new_line += line[start:m.start()].replace('%', '%%')
+          new_line += line[m.start():m.end()]
+          start = m.end()
+        new_line += line[start:].replace('%', '%%')
+        line = new_line
+
         subst_line = r'r"""%s""" %% (%s,)' % (
             re.sub(expr_re, '%s', line),
             ', '.join(re.findall(expr_re, line)))
       else:
         subst_line = r'r"""%s"""' % line
 
       out_string = r'%s__outfile__.write(%s + %s)' % (
           indent_string,
           subst_line,
           repr(line_ending))
@@ skipping 45 matching lines @@
   _, args = parser.parse_args(args)
   if not args:
     return
 
   with open(args[0]) as f:
     print TemplateToPython(
         f.read(), re.compile(STATEMENT_RE), re.compile(EXPR_RE))
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))