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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                    ast.FUNCTION_OVERRIDE)
     54   ctor_or_dtor = ast.FUNCTION_CTOR | ast.FUNCTION_DTOR
     55   indent = ' ' * _INDENT
     56 
     57   for node in class_node.body:
     58     # We only care about virtual functions.
     59     if (isinstance(node, ast.Function) and
     60         node.modifiers & function_type and
     61         not node.modifiers & ctor_or_dtor):
     62       # Pick out all the elements we need from the original function.
     63       const = ''
     64       if node.modifiers & ast.FUNCTION_CONST:
     65         const = 'CONST_'
     66       return_type = 'void'
     67       if node.return_type:
     68         # Add modifiers like 'const'.
     69         modifiers = ''
     70         if node.return_type.modifiers:
     71           modifiers = ' '.join(node.return_type.modifiers) + ' '
     72         return_type = modifiers + node.return_type.name
     73         template_args = [arg.name for arg in node.return_type.templated_types]
     74         if template_args:
     75           return_type += '<' + ', '.join(template_args) + '>'
     76           if len(template_args) > 1:
     77             for line in [
     78                 '// The following line won\'t really compile, as the return',
     79                 '// type has multiple template arguments.  To fix it, use a',
     80                 '// typedef for the return type.']:
     81               output_lines.append(indent + line)
     82         if node.return_type.pointer:
     83           return_type += '*'
     84         if node.return_type.reference:
     85           return_type += '&'
     86         num_parameters = len(node.parameters)
     87         if len(node.parameters) == 1:
     88           first_param = node.parameters[0]
     89           if source[first_param.start:first_param.end].strip() == 'void':
     90             # We must treat T(void) as a function with no parameters.
     91             num_parameters = 0
     92       tmpl = ''
     93       if class_node.templated_types:
     94         tmpl = '_T'
     95       mock_method_macro = 'MOCK_%sMETHOD%d%s' % (const, num_parameters, tmpl)
     96 
     97       args = ''
     98       if node.parameters:
     99         # Due to the parser limitations, it is impossible to keep comments
    100         # while stripping the default parameters.  When defaults are
    101         # present, we choose to strip them and comments (and produce
    102         # compilable code).
    103         # TODO(nnorwitz (at] google.com): Investigate whether it is possible to
    104         # preserve parameter name when reconstructing parameter text from
    105         # the AST.
    106         if len([param for param in node.parameters if param.default]) > 0:
    107           args = ', '.join(param.type.name for param in node.parameters)
    108         else:
    109           # Get the full text of the parameters from the start
    110           # of the first parameter to the end of the last parameter.
    111           start = node.parameters[0].start
    112           end = node.parameters[-1].end
    113           # Remove // comments.
    114           args_strings = re.sub(r'//.*', '', source[start:end])
    115           # Condense multiple spaces and eliminate newlines putting the
    116           # parameters together on a single line.  Ensure there is a
    117           # space in an argument which is split by a newline without
    118           # intervening whitespace, e.g.: int\nBar
    119           args = re.sub('  +', ' ', args_strings.replace('\n', ' '))
    120 
    121       # Create the mock method definition.
    122       output_lines.extend(['%s%s(%s,' % (indent, mock_method_macro, node.name),
    123                            '%s%s(%s));' % (indent*3, return_type, args)])
    124 
    125 
    126 def _GenerateMocks(filename, source, ast_list, desired_class_names):
    127   processed_class_names = set()
    128   lines = []
    129   for node in ast_list:
    130     if (isinstance(node, ast.Class) and node.body and
    131         # desired_class_names being None means that all classes are selected.
    132         (not desired_class_names or node.name in desired_class_names)):
    133       class_name = node.name
    134       parent_name = class_name
    135       processed_class_names.add(class_name)
    136       class_node = node
    137       # Add namespace before the class.
    138       if class_node.namespace:
    139         lines.extend(['namespace %s {' % n for n in class_node.namespace])  # }
    140         lines.append('')
    141 
    142       # Add template args for templated classes.
    143       if class_node.templated_types:
    144         # TODO(paulchang): The AST doesn't preserve template argument order,
    145         # so we have to make up names here.
    146         # TODO(paulchang): Handle non-type template arguments (e.g.
    147         # template<typename T, int N>).
    148         template_arg_count = len(class_node.templated_types.keys())
    149         template_args = ['T%d' % n for n in range(template_arg_count)]
    150         template_decls = ['typename ' + arg for arg in template_args]
    151         lines.append('template <' + ', '.join(template_decls) + '>')
    152         parent_name += '<' + ', '.join(template_args) + '>'
    153 
    154       # Add the class prolog.
    155       lines.append('class Mock%s : public %s {'  # }
    156                    % (class_name, parent_name))
    157       lines.append('%spublic:' % (' ' * (_INDENT // 2)))
    158 
    159       # Add all the methods.
    160       _GenerateMethods(lines, source, class_node)
    161 
    162       # Close the class.
    163       if lines:
    164         # If there are no virtual methods, no need for a public label.
    165         if len(lines) == 2:
    166           del lines[-1]
    167 
    168         # Only close the class if there really is a class.
    169         lines.append('};')
    170         lines.append('')  # Add an extra newline.
    171 
    172       # Close the namespace.
    173       if class_node.namespace:
    174         for i in range(len(class_node.namespace)-1, -1, -1):
    175           lines.append('}  // namespace %s' % class_node.namespace[i])
    176         lines.append('')  # Add an extra newline.
    177 
    178   if desired_class_names:
    179     missing_class_name_list = list(desired_class_names - processed_class_names)
    180     if missing_class_name_list:
    181       missing_class_name_list.sort()
    182       sys.stderr.write('Class(es) not found in %s: %s\n' %
    183                        (filename, ', '.join(missing_class_name_list)))
    184   elif not processed_class_names:
    185     sys.stderr.write('No class found in %s\n' % filename)
    186 
    187   return lines
    188 
    189 
    190 def main(argv=sys.argv):
    191   if len(argv) < 2:
    192     sys.stderr.write('Google Mock Class Generator v%s\n\n' %
    193                      '.'.join(map(str, _VERSION)))
    194     sys.stderr.write(__doc__)
    195     return 1
    196 
    197   global _INDENT
    198   try:
    199     _INDENT = int(os.environ['INDENT'])
    200   except KeyError:
    201     pass
    202   except:
    203     sys.stderr.write('Unable to use indent of %s\n' % os.environ.get('INDENT'))
    204 
    205   filename = argv[1]
    206   desired_class_names = None  # None means all classes in the source file.
    207   if len(argv) >= 3:
    208     desired_class_names = set(argv[2:])
    209   source = utils.ReadFile(filename)
    210   if source is None:
    211     return 1
    212 
    213   builder = ast.BuilderFromSource(source, filename)
    214   try:
    215     entire_ast = filter(None, builder.Generate())
    216   except KeyboardInterrupt:
    217     return
    218   except:
    219     # An error message was already printed since we couldn't parse.
    220     sys.exit(1)
    221   else:
    222     lines = _GenerateMocks(filename, source, entire_ast, desired_class_names)
    223     sys.stdout.write('\n'.join(lines))
    224 
    225 
    226 if __name__ == '__main__':
    227   main(sys.argv)
    228