native_client_sdk/src/build_tools/easy_template.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 import argparse
   7 import copy
   8 import cStringIO
   9 import os
  10 import re
  11 import sys
  12
  13
  14 STATEMENT_RE = "\[\[(.*?)\]\]"  # [[...]]
  15 EXPR_RE = "\{\{(.*?)\}\}"  # {{...}}
  16
  17 def TemplateToPython(template, statement_re, expr_re):
  18   output = cStringIO.StringIO()
  19   indent_re = re.compile(r'\s*')
  20   indent_string = ''
  21   for line in template.splitlines(1):  # 1 => keep line ends
  22     m = statement_re.match(line)
  23     if m:
  24       statement = m.group(1)
  25       indent_string = indent_re.match(statement).group()
  26       if statement.rstrip()[-1:] == ':':
  27         indent_string += '  '
  28       output.write(statement + '\n')
  29     else:
  30       line_ending = ''
  31       while line and line[-1] in '\\"\n\r':
  32         line_ending = line[-1] + line_ending
  33         line = line[:-1]
  34
  35       ms = list(expr_re.finditer(line))
  36       if ms:
  37         # Only replace % with %% outside of the expr matches.
  38         new_line = ''
  39         start = 0
  40         for m in ms:
  41           new_line += line[start:m.start()].replace('%', '%%')
  42           new_line += line[m.start():m.end()]
  43           start = m.end()
  44         new_line += line[start:].replace('%', '%%')
  45         line = new_line
  46
  47         subst_line = r'r"""%s""" %% (%s,)' % (
  48             re.sub(expr_re, '%s', line),
  49             ', '.join(re.findall(expr_re, line)))
  50       else:
  51         subst_line = r'r"""%s"""' % line
  52
  53       out_string = r'%s__outfile__.write(%s + %s)' % (
  54           indent_string,
  55           subst_line,
  56           repr(line_ending))
  57       output.write(out_string + '\n')
  58
  59   return output.getvalue()
  60
  61
  62 def RunTemplate(srcfile, dstfile, template_dict, statement_re=None,
  63                 expr_re=None):
  64   statement_re = statement_re or re.compile(STATEMENT_RE)
  65   expr_re = expr_re or re.compile(EXPR_RE)
  66   script = TemplateToPython(srcfile.read(), statement_re, expr_re)
  67   template_dict = copy.copy(template_dict)
  68   template_dict['__outfile__'] = dstfile
  69   exec script in template_dict
  70
  71
  72 def RunTemplateFile(srcpath, dstpath, template_dict, statement_re=None,
  73                     expr_re=None):
  74   with open(srcpath) as srcfile:
  75     with open(dstpath, 'w') as dstfile:
  76       RunTemplate(srcfile, dstfile, template_dict, statement_re, expr_re)
  77
  78
  79 def RunTemplateFileIfChanged(srcpath, dstpath, replace):
  80   dststr = cStringIO.StringIO()
  81   with open(srcpath) as srcfile:
  82     RunTemplate(srcfile, dststr, replace)
  83
  84   if os.path.exists(dstpath):
  85     with open(dstpath) as dstfile:
  86       if dstfile.read() == dststr.getvalue():
  87         return
  88
  89   with open(dstpath, 'w') as dstfile:
  90     dstfile.write(dststr.getvalue())
  91
  92
  93 def RunTemplateString(src, template_dict, statement_re=None, expr_re=None):
  94   srcstr = cStringIO.StringIO(src)
  95   dststr = cStringIO.StringIO()
  96   RunTemplate(srcstr, dststr, template_dict, statement_re, expr_re)
  97   return dststr.getvalue()
  98
  99
 100 def main(args):
 101   parser = argparse.ArgumentParser()
 102   parser.add_argument('template')
 103   options = parser.parse_args(args)
 104
 105   with open(options.template) as f:
 106     print TemplateToPython(
 107         f.read(), re.compile(STATEMENT_RE), re.compile(EXPR_RE))
 108
 109 if __name__ == '__main__':
 110   sys.exit(main(sys.argv[1:]))