buildtools/wafadmin/Environment.py

   1 #!/usr/bin/env python
   2 # encoding: utf-8
   3 # Thomas Nagy, 2005 (ita)
   4
   5 """Environment representation
   6
   7 There is one gotcha: getitem returns [] if the contents evals to False
   8 This means env['foo'] = {}; print env['foo'] will print [] not {}
   9 """
  10
  11 import os, copy, re
  12 import Logs, Options, Utils
  13 from Constants import *
  14 re_imp = re.compile('^(#)*?([^#=]*?)\ =\ (.*?)$', re.M)
  15
  16 class Environment(object):
  17         """A safe-to-use dictionary, but do not attach functions to it please (break cPickle)
  18         An environment instance can be stored into a file and loaded easily
  19         """
  20         __slots__ = ("table", "parent")
  21         def __init__(self, filename=None):
  22                 self.table = {}
  23                 #self.parent = None
  24
  25                 if filename:
  26                         self.load(filename)
  27
  28         def __contains__(self, key):
  29                 if key in self.table: return True
  30                 try: return self.parent.__contains__(key)
  31                 except AttributeError: return False # parent may not exist
  32
  33         def __str__(self):
  34                 keys = set()
  35                 cur = self
  36                 while cur:
  37                         keys.update(cur.table.keys())
  38                         cur = getattr(cur, 'parent', None)
  39                 keys = list(keys)
  40                 keys.sort()
  41                 return "\n".join(["%r %r" % (x, self.__getitem__(x)) for x in keys])
  42
  43         def __getitem__(self, key):
  44                 try:
  45                         while 1:
  46                                 x = self.table.get(key, None)
  47                                 if not x is None:
  48                                         return x
  49                                 self = self.parent
  50                 except AttributeError:
  51                         return []
  52
  53         def __setitem__(self, key, value):
  54                 self.table[key] = value
  55
  56         def __delitem__(self, key):
  57                 del self.table[key]
  58
  59         def pop(self, key, *args):
  60                 if len(args):
  61                         return self.table.pop(key, *args)
  62                 return self.table.pop(key)
  63
  64         def set_variant(self, name):
  65                 self.table[VARIANT] = name
  66
  67         def variant(self):
  68                 try:
  69                         while 1:
  70                                 x = self.table.get(VARIANT, None)
  71                                 if not x is None:
  72                                         return x
  73                                 self = self.parent
  74                 except AttributeError:
  75                         return DEFAULT
  76
  77         def copy(self):
  78                 # TODO waf 1.6 rename this method derive, #368
  79                 newenv = Environment()
  80                 newenv.parent = self
  81                 return newenv
  82
  83         def detach(self):
  84                 """TODO try it
  85                 modifying the original env will not change the copy"""
  86                 tbl = self.get_merged_dict()
  87                 try:
  88                         delattr(self, 'parent')
  89                 except AttributeError:
  90                         pass
  91                 else:
  92                         keys = tbl.keys()
  93                         for x in keys:
  94                                 tbl[x] = copy.deepcopy(tbl[x])
  95                         self.table = tbl
  96
  97         def get_flat(self, key):
  98                 s = self[key]
  99                 if isinstance(s, str): return s
 100                 return ' '.join(s)
 101
 102         def _get_list_value_for_modification(self, key):
 103                 """Gets a value that must be a list for further modification.  The
 104                 list may be modified inplace and there is no need to
 105                 "self.table[var] = value" afterwards.
 106                 """
 107                 try:
 108                         value = self.table[key]
 109                 except KeyError:
 110                         try: value = self.parent[key]
 111                         except AttributeError: value = []
 112                         if isinstance(value, list):
 113                                 value = value[:]
 114                         else:
 115                                 value = [value]
 116                 else:
 117                         if not isinstance(value, list):
 118                                 value = [value]
 119                 self.table[key] = value
 120                 return value
 121
 122         def append_value(self, var, value):
 123                 current_value = self._get_list_value_for_modification(var)
 124
 125                 if isinstance(value, list):
 126                         current_value.extend(value)
 127                 else:
 128                         current_value.append(value)
 129
 130         def prepend_value(self, var, value):
 131                 current_value = self._get_list_value_for_modification(var)
 132
 133                 if isinstance(value, list):
 134                         current_value = value + current_value
 135                         # a new list: update the dictionary entry
 136                         self.table[var] = current_value
 137                 else:
 138                         current_value.insert(0, value)
 139
 140         # prepend unique would be ambiguous
 141         def append_unique(self, var, value):
 142                 current_value = self._get_list_value_for_modification(var)
 143
 144                 if isinstance(value, list):
 145                         for value_item in value:
 146                                 if value_item not in current_value:
 147                                         current_value.append(value_item)
 148                 else:
 149                         if value not in current_value:
 150                                 current_value.append(value)
 151
 152         def get_merged_dict(self):
 153                 """compute a merged table"""
 154                 table_list = []
 155                 env = self
 156                 while 1:
 157                         table_list.insert(0, env.table)
 158                         try: env = env.parent
 159                         except AttributeError: break
 160                 merged_table = {}
 161                 for table in table_list:
 162                         merged_table.update(table)
 163                 return merged_table
 164
 165         def store(self, filename):
 166                 "Write the variables into a file"
 167                 file = open(filename, 'w')
 168                 merged_table = self.get_merged_dict()
 169                 keys = list(merged_table.keys())
 170                 keys.sort()
 171                 for k in keys: file.write('%s = %r\n' % (k, merged_table[k]))
 172                 file.close()
 173
 174         def load(self, filename):
 175                 "Retrieve the variables from a file"
 176                 tbl = self.table
 177                 code = Utils.readf(filename)
 178                 for m in re_imp.finditer(code):
 179                         g = m.group
 180                         tbl[g(2)] = eval(g(3))
 181                 Logs.debug('env: %s', self.table)
 182
 183         def get_destdir(self):
 184                 "return the destdir, useful for installing"
 185                 if self.__getitem__('NOINSTALL'): return ''
 186                 return Options.options.destdir
 187
 188         def update(self, d):
 189                 for k, v in d.iteritems():
 190                         self[k] = v
 191
 192
 193         def __getattr__(self, name):
 194                 if name in self.__slots__:
 195                         return object.__getattr__(self, name)
 196                 else:
 197                         return self[name]
 198
 199         def __setattr__(self, name, value):
 200                 if name in self.__slots__:
 201                         object.__setattr__(self, name, value)
 202                 else:
 203                         self[name] = value
 204
 205         def __delattr__(self, name):
 206                 if name in self.__slots__:
 207                         object.__delattr__(self, name)
 208                 else:
 209                         del self[name]
 210