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      1 #!/usr/bin/env python
      2 #
      3 # Copyright 2008 Google Inc.  All Rights Reserved.
      4 #
      5 # Licensed under the Apache License, Version 2.0 (the "License");
      6 # you may not use this file except in compliance with the License.
      7 # You may obtain a copy of the License at
      8 #
      9 #      http://www.apache.org/licenses/LICENSE-2.0
     10 #
     11 # Unless required by applicable law or agreed to in writing, software
     12 # distributed under the License is distributed on an "AS IS" BASIS,
     13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14 # See the License for the specific language governing permissions and
     15 # limitations under the License.
     16 
     17 """Generate Google Mock classes from base classes.
     18 
     19 This program will read in a C++ source file and output the Google Mock
     20 classes for the specified classes.  If no class is specified, all
     21 classes in the source file are emitted.
     22 
     23 Usage:
     24   gmock_class.py header-file.h [ClassName]...
     25 
     26 Output is sent to stdout.
     27 """
     28 
     29 __author__ = 'nnorwitz (at] google.com (Neal Norwitz)'
     30 
     31 
     32 import os
     33 import re
     34 import sys
     35 
     36 from cpp import ast
     37 from cpp import utils
     38 
     39 # Preserve compatibility with Python 2.3.
     40 try:
     41   _dummy = set
     42 except NameError:
     43   import sets
     44   set = sets.Set
     45 
     46 _VERSION = (1, 0, 1)  # The version of this script.
     47 # How many spaces to indent.  Can set me with the INDENT environment variable.
     48 _INDENT = 2
     49 
     50 
     51 def _GenerateMethods(output_lines, source, class_node):
     52   function_type = ast.FUNCTION_VIRTUAL | ast.FUNCTION_PURE_VIRTUAL
     53   ctor_or_dtor = ast.FUNCTION_CTOR | ast.FUNCTION_DTOR
     54   indent = ' ' * _INDENT
     55 
     56   for node in class_node.body:
     57     # We only care about virtual functions.
     58     if (isinstance(node, ast.Function) and
     59         node.modifiers & function_type and
     60         not node.modifiers & ctor_or_dtor):
     61       # Pick out all the elements we need from the original function.
     62       const = ''
     63       if node.modifiers & ast.FUNCTION_CONST:
     64         const = 'CONST_'
     65       return_type = 'void'
     66       if node.return_type:
     67         # Add modifiers like 'const'.
     68         modifiers = ''
     69         if node.return_type.modifiers:
     70           modifiers = ' '.join(node.return_type.modifiers) + ' '
     71         return_type = modifiers + node.return_type.name
     72         template_args = [arg.name for arg in node.return_type.templated_types]
     73         if template_args:
     74           return_type += '<' + ', '.join(template_args) + '>'
     75           if len(template_args) > 1:
     76             for line in [
     77                 '// The following line won\'t really compile, as the return',
     78                 '// type has multiple template arguments.  To fix it, use a',
     79                 '// typedef for the return type.']:
     80               output_lines.append(indent + line)
     81         if node.return_type.pointer:
     82           return_type += '*'
     83         if node.return_type.reference:
     84           return_type += '&'
     85         num_parameters = len(node.parameters)
     86         if len(node.parameters) == 1:
     87           first_param = node.parameters[0]
     88           if source[first_param.start:first_param.end].strip() == 'void':
     89             # We must treat T(void) as a function with no parameters.
     90             num_parameters = 0
     91       mock_method_macro = 'MOCK_%sMETHOD%d' % (const, num_parameters)
     92       args = ''
     93       if node.parameters:
     94         # Due to the parser limitations, it is impossible to keep comments
     95         # while stripping the default parameters.  When defaults are
     96         # present, we choose to strip them and comments (and produce
     97         # compilable code).
     98         # TODO(nnorwitz (at] google.com): Investigate whether it is possible to
     99         # preserve parameter name when reconstructing parameter text from
    100         # the AST.
    101         if len([param for param in node.parameters if param.default]) > 0:
    102           args = ', '.join(param.type.name for param in node.parameters)
    103         else:
    104           # Get the full text of the parameters from the start
    105           # of the first parameter to the end of the last parameter.
    106           start = node.parameters[0].start
    107           end = node.parameters[-1].end
    108           # Remove // comments.
    109           args_strings = re.sub(r'//.*', '', source[start:end])
    110           # Condense multiple spaces and eliminate newlines putting the
    111           # parameters together on a single line.  Ensure there is a
    112           # space in an argument which is split by a newline without
    113           # intervening whitespace, e.g.: int\nBar
    114           args = re.sub('  +', ' ', args_strings.replace('\n', ' '))
    115 
    116       # Create the mock method definition.
    117       output_lines.extend(['%s%s(%s,' % (indent, mock_method_macro, node.name),
    118                            '%s%s(%s));' % (indent*3, return_type, args)])
    119 
    120 
    121 def _GenerateMocks(filename, source, ast_list, desired_class_names):
    122   processed_class_names = set()
    123   lines = []
    124   for node in ast_list:
    125     if (isinstance(node, ast.Class) and node.body and
    126         # desired_class_names being None means that all classes are selected.
    127         (not desired_class_names or node.name in desired_class_names)):
    128       class_name = node.name
    129       processed_class_names.add(class_name)
    130       class_node = node
    131       # Add namespace before the class.
    132       if class_node.namespace:
    133         lines.extend(['namespace %s {' % n for n in class_node.namespace])  # }
    134         lines.append('')
    135 
    136       # Add the class prolog.
    137       lines.append('class Mock%s : public %s {' % (class_name, class_name))  # }
    138       lines.append('%spublic:' % (' ' * (_INDENT // 2)))
    139 
    140       # Add all the methods.
    141       _GenerateMethods(lines, source, class_node)
    142 
    143       # Close the class.
    144       if lines:
    145         # If there are no virtual methods, no need for a public label.
    146         if len(lines) == 2:
    147           del lines[-1]
    148 
    149         # Only close the class if there really is a class.
    150         lines.append('};')
    151         lines.append('')  # Add an extra newline.
    152 
    153       # Close the namespace.
    154       if class_node.namespace:
    155         for i in range(len(class_node.namespace)-1, -1, -1):
    156           lines.append('}  // namespace %s' % class_node.namespace[i])
    157         lines.append('')  # Add an extra newline.
    158 
    159   if desired_class_names:
    160     missing_class_name_list = list(desired_class_names - processed_class_names)
    161     if missing_class_name_list:
    162       missing_class_name_list.sort()
    163       sys.stderr.write('Class(es) not found in %s: %s\n' %
    164                        (filename, ', '.join(missing_class_name_list)))
    165   elif not processed_class_names:
    166     sys.stderr.write('No class found in %s\n' % filename)
    167 
    168   return lines
    169 
    170 
    171 def main(argv=sys.argv):
    172   if len(argv) < 2:
    173     sys.stderr.write('Google Mock Class Generator v%s\n\n' %
    174                      '.'.join(map(str, _VERSION)))
    175     sys.stderr.write(__doc__)
    176     return 1
    177 
    178   global _INDENT
    179   try:
    180     _INDENT = int(os.environ['INDENT'])
    181   except KeyError:
    182     pass
    183   except:
    184     sys.stderr.write('Unable to use indent of %s\n' % os.environ.get('INDENT'))
    185 
    186   filename = argv[1]
    187   desired_class_names = None  # None means all classes in the source file.
    188   if len(argv) >= 3:
    189     desired_class_names = set(argv[2:])
    190   source = utils.ReadFile(filename)
    191   if source is None:
    192     return 1
    193 
    194   builder = ast.BuilderFromSource(source, filename)
    195   try:
    196     entire_ast = filter(None, builder.Generate())
    197   except KeyboardInterrupt:
    198     return
    199   except:
    200     # An error message was already printed since we couldn't parse.
    201     pass
    202   else:
    203     lines = _GenerateMocks(filename, source, entire_ast, desired_class_names)
    204     sys.stdout.write('\n'.join(lines))
    205 
    206 
    207 if __name__ == '__main__':
    208   main(sys.argv)
    209