tools/idl_parser/idl_node.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2012 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 sys
   7
   8 #
   9 # IDL Node
  10 #
  11 # IDL Node defines the IDLAttribute and IDLNode objects which are constructed
  12 # by the parser as it processes the various 'productions'.  The IDLAttribute
  13 # objects are assigned to the IDLNode's property dictionary instead of being
  14 # applied as children of The IDLNodes, so they do not exist in the final tree.
  15 # The AST of IDLNodes is the output from the parsing state and will be used
  16 # as the source data by the various generators.
  17 #
  18
  19
  20 #
  21 # CopyToList
  22 #
  23 # Takes an input item, list, or None, and returns a new list of that set.
  24 def CopyToList(item):
  25   # If the item is 'Empty' make it an empty list
  26   if not item:
  27     item = []
  28
  29   # If the item is not a list
  30   if type(item) is not type([]):
  31     item = [item]
  32
  33   # Make a copy we can modify
  34   return list(item)
  35
  36
  37 # IDLSearch
  38 #
  39 # A temporary object used by the parsing process to hold an Extended Attribute
  40 # which will be passed as a child to a standard IDLNode.
  41 #
  42 class IDLSearch(object):
  43   def __init__(self):
  44     self.depth = 0
  45
  46   def Enter(self, node):
  47     pass
  48
  49   def Exit(self, node):
  50     pass
  51
  52
  53 # IDLAttribute
  54 #
  55 # A temporary object used by the parsing process to hold an Extended Attribute
  56 # which will be passed as a child to a standard IDLNode.
  57 #
  58 class IDLAttribute(object):
  59   def __init__(self, name, value):
  60     self._cls = 'Property'
  61     self.name = name
  62     self.value = value
  63
  64   def __str__(self):
  65     return '%s=%s' % (self.name, self.value)
  66
  67   def GetClass(self):
  68     return self._cls
  69
  70 #
  71 # IDLNode
  72 #
  73 # This class implements the AST tree, providing the associations between
  74 # parents and children.  It also contains a namepsace and propertynode to
  75 # allow for look-ups.  IDLNode is derived from IDLRelease, so it is
  76 # version aware.
  77 #
  78 class IDLNode(object):
  79   def __init__(self, cls, filename, lineno, pos, children=None):
  80     self._cls = cls
  81     self._properties = {
  82       'ERRORS' : [],
  83       'WARNINGS': [],
  84       'FILENAME': filename,
  85       'LINENO' : lineno,
  86       'POSSITION' : pos,
  87     }
  88
  89     self._children = []
  90     self._parent = None
  91     self.AddChildren(children)
  92
  93 #
  94 #
  95 #
  96   # Return a string representation of this node
  97   def __str__(self):
  98     name = self.GetProperty('NAME','')
  99     return '%s(%s)' % (self._cls, name)
 100
 101   def GetLogLine(self, msg):
 102     filename, lineno = self.GetFileAndLine()
 103     return '%s(%d) : %s\n' % (filename, lineno, msg)
 104
 105   # Log an error for this object
 106   def Error(self, msg):
 107     self.GetProperty('ERRORS').append(msg)
 108     sys.stderr.write(self.GetLogLine('error: ' + msg))
 109
 110   # Log a warning for this object
 111   def Warning(self, msg):
 112     self.GetProperty('WARNINGS').append(msg)
 113     sys.stdout.write(self.GetLogLine('warning:' + msg))
 114
 115   # Return file and line number for where node was defined
 116   def GetFileAndLine(self):
 117     return self.GetProperty('FILENAME'), self.GetProperty('LINENO')
 118
 119   def GetClass(self):
 120     return self._cls
 121
 122   def GetName(self):
 123     return self.GetProperty('NAME')
 124
 125   def GetParent(self):
 126     return self._parent
 127
 128   def Traverse(self, search, filter_nodes):
 129     if self._cls in filter_nodes:
 130       return ''
 131
 132     search.Enter(self)
 133     search.depth += 1
 134     for child in self._children:
 135       child.Traverse(search, filter_nodes)
 136     search.depth -= 1
 137     search.Exit(self)
 138
 139
 140   def Tree(self, filter_nodes=None, accept_props=None):
 141     class DumpTreeSearch(IDLSearch):
 142       def __init__(self, props):
 143         IDLSearch.__init__(self)
 144         self.out = []
 145         self.props = props
 146
 147       def Enter(self, node):
 148         tab = ''.rjust(self.depth * 2)
 149         self.out.append(tab + str(node))
 150         if self.props:
 151           proplist = []
 152           for key, value in node.GetProperties().iteritems():
 153             if key in self.props:
 154               proplist.append(tab + '    %s: %s' % (key, str(value)))
 155           if proplist:
 156             self.out.append(tab + '  PROPERTIES')
 157             self.out.extend(proplist)
 158
 159     if filter_nodes == None:
 160       filter_nodes = ['Comment', 'Copyright']
 161
 162     search = DumpTreeSearch(accept_props)
 163     self.Traverse(search, filter_nodes)
 164     return search.out
 165
 166 #
 167 # Search related functions
 168 #
 169   # Check if node is of a given type
 170   def IsA(self, *typelist):
 171     if self._cls in typelist:
 172       return True
 173     return False
 174
 175   # Get a list of all children
 176   def GetChildren(self):
 177     return self._children
 178
 179   def GetListOf(self, *keys):
 180     out = []
 181     for child in self.GetChildren():
 182       if child.GetClass() in keys:
 183         out.append(child)
 184     return out
 185
 186   def GetOneOf(self, *keys):
 187     out = self.GetListOf(*keys)
 188     if out:
 189       return out[0]
 190     return None
 191
 192   def AddChildren(self, children):
 193     children = CopyToList(children)
 194     for child in children:
 195       if not child:
 196         continue
 197       if type(child) == IDLAttribute:
 198         self.SetProperty(child.name, child.value)
 199         continue
 200       if type(child) == IDLNode:
 201         child._parent = self
 202         self._children.append(child)
 203         continue
 204       raise RuntimeError('Adding child of type .\n' % type(child).__name__)
 205
 206
 207 #
 208 # Property Functions
 209 #
 210   def SetProperty(self, name, val):
 211     self._properties[name] = val
 212
 213   def GetProperty(self, name, default=None):
 214     return self._properties.get(name, default)
 215
 216   def GetProperties(self):
 217     return self._properties