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      1 #!/usr/bin/env python
      2 #
      3 # Copyright (C) 2012 The Android Open Source Project
      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 """Generates default implementations of operator<< for enum types."""
     18 
     19 import codecs
     20 import os
     21 import re
     22 import string
     23 import sys
     24 
     25 
     26 _ENUM_START_RE = re.compile(r'\benum\b\s+(class\s+)?(\S+)\s+:?.*\{(\s+// private)?')
     27 _ENUM_VALUE_RE = re.compile(r'([A-Za-z0-9_]+)(.*)')
     28 _ENUM_END_RE = re.compile(r'^\s*\};$')
     29 _ENUMS = {}
     30 _NAMESPACES = {}
     31 _ENUM_CLASSES = {}
     32 
     33 def Confused(filename, line_number, line):
     34   sys.stderr.write('%s:%d: confused by:\n%s\n' % (filename, line_number, line))
     35   raise Exception("giving up!")
     36   sys.exit(1)
     37 
     38 
     39 def ProcessFile(filename):
     40   lines = codecs.open(filename, 'r', 'utf8', 'replace').read().split('\n')
     41   in_enum = False
     42   is_enum_private = False
     43   is_enum_class = False
     44   line_number = 0
     45   
     46 
     47   namespaces = []
     48   enclosing_classes = []
     49 
     50   for raw_line in lines:
     51     line_number += 1
     52 
     53     if not in_enum:
     54       # Is this the start of a new enum?
     55       m = _ENUM_START_RE.search(raw_line)
     56       if m:
     57         # Yes, so add an empty entry to _ENUMS for this enum.
     58         
     59         # Except when it's private
     60         if m.group(3) is not None:
     61           is_enum_private = True
     62         else:
     63           is_enum_private = False
     64           is_enum_class = m.group(1) is not None
     65           enum_name = m.group(2)
     66           if len(enclosing_classes) > 0:
     67             enum_name = '::'.join(enclosing_classes) + '::' + enum_name
     68           _ENUMS[enum_name] = []
     69           _NAMESPACES[enum_name] = '::'.join(namespaces)
     70           _ENUM_CLASSES[enum_name] = is_enum_class
     71         in_enum = True
     72         continue
     73 
     74       # Is this the start or end of a namespace?
     75       m = re.compile(r'^namespace (\S+) \{').search(raw_line)
     76       if m:
     77         namespaces.append(m.group(1))
     78         continue
     79       m = re.compile(r'^\}\s+// namespace').search(raw_line)
     80       if m:
     81         namespaces = namespaces[0:len(namespaces) - 1]
     82         continue
     83 
     84       # Is this the start or end of an enclosing class or struct?
     85       m = re.compile(r'^\s*(?:class|struct)(?: MANAGED)?(?: PACKED\([0-9]\))? (\S+).* \{').search(raw_line)
     86       if m:
     87         enclosing_classes.append(m.group(1))
     88         continue
     89 
     90       # End of class/struct -- be careful not to match "do { ... } while" constructs by accident
     91       m = re.compile(r'^\s*\}(\s+)?(while)?(.+)?;').search(raw_line)
     92       if m and not m.group(2):
     93         enclosing_classes = enclosing_classes[0:len(enclosing_classes) - 1]
     94         continue
     95 
     96       continue
     97 
     98     # Is this the end of the current enum?
     99     m = _ENUM_END_RE.search(raw_line)
    100     if m:
    101       if not in_enum:
    102         Confused(filename, line_number, raw_line)
    103       in_enum = False
    104       continue
    105 
    106     if is_enum_private:
    107       continue
    108 
    109     # The only useful thing in comments is the <<alternate text>> syntax for
    110     # overriding the default enum value names. Pull that out...
    111     enum_text = None
    112     m_comment = re.compile(r'// <<(.*?)>>').search(raw_line)
    113     if m_comment:
    114       enum_text = m_comment.group(1)
    115     # ...and then strip // comments.
    116     line = re.sub(r'//.*', '', raw_line)
    117 
    118     # Strip whitespace.
    119     line = line.strip()
    120 
    121     # Skip blank lines.
    122     if len(line) == 0:
    123       continue
    124 
    125     # Since we know we're in an enum type, and we're not looking at a comment
    126     # or a blank line, this line should be the next enum value...
    127     m = _ENUM_VALUE_RE.search(line)
    128     if not m:
    129       Confused(filename, line_number, raw_line)
    130     enum_value = m.group(1)
    131 
    132     # By default, we turn "kSomeValue" into "SomeValue".
    133     if enum_text == None:
    134       enum_text = enum_value
    135       if enum_text.startswith('k'):
    136         enum_text = enum_text[1:]
    137 
    138     # Lose literal values because we don't care; turn "= 123, // blah" into ", // blah".
    139     rest = m.group(2).strip()
    140     m_literal = re.compile(r'= (0x[0-9a-f]+|-?[0-9]+|\'.\')').search(rest)
    141     if m_literal:
    142       rest = rest[(len(m_literal.group(0))):]
    143 
    144     # With "kSomeValue = kOtherValue," we take the original and skip later synonyms.
    145     # TODO: check that the rhs is actually an existing value.
    146     if rest.startswith('= k'):
    147       continue
    148 
    149     # Remove any trailing comma and whitespace
    150     if rest.startswith(','):
    151       rest = rest[1:]
    152     rest = rest.strip()
    153 
    154     # There shouldn't be anything left.
    155     if len(rest):
    156       sys.stderr.write('%s\n' % (rest))
    157       Confused(filename, line_number, raw_line)
    158 
    159     # If the enum is scoped, we must prefix enum value with enum name (which is already prefixed
    160     # by enclosing classes).
    161     if is_enum_class:
    162       enum_value = enum_name + '::' + enum_value
    163     else:
    164       if len(enclosing_classes) > 0:
    165         enum_value = '::'.join(enclosing_classes) + '::' + enum_value
    166 
    167     _ENUMS[enum_name].append((enum_value, enum_text))
    168 
    169 def main():
    170   local_path = sys.argv[1]
    171   header_files = []
    172   for header_file in sys.argv[2:]:
    173     header_files.append(header_file)
    174     ProcessFile(header_file)
    175 
    176   print('#include <iostream>')
    177   print('')
    178 
    179   for header_file in header_files:
    180     header_file = header_file.replace(local_path + '/', '')
    181     print('#include "%s"' % header_file)
    182 
    183   print('')
    184 
    185   for enum_name in _ENUMS:
    186     print('// This was automatically generated by %s --- do not edit!' % sys.argv[0])
    187 
    188     namespaces = _NAMESPACES[enum_name].split('::')
    189     for namespace in namespaces:
    190       print('namespace %s {' % namespace)
    191 
    192     print('std::ostream& operator<<(std::ostream& os, const %s& rhs) {' % enum_name)
    193     print('  switch (rhs) {')
    194     for (enum_value, enum_text) in _ENUMS[enum_name]:
    195       print('    case %s: os << "%s"; break;' % (enum_value, enum_text))
    196     if not _ENUM_CLASSES[enum_name]:
    197       print('    default: os << "%s[" << static_cast<int>(rhs) << "]"; break;' % enum_name)
    198     print('  }')
    199     print('  return os;')
    200     print('}')
    201 
    202     for namespace in reversed(namespaces):
    203       print('}  // namespace %s' % namespace)
    204     print('')
    205 
    206   sys.exit(0)
    207 
    208 
    209 if __name__ == '__main__':
    210   main()
    211