ppapi/generators/idl_ast.py

   1 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 """Nodes for PPAPI IDL AST."""
   6
   7 from idl_namespace import IDLNamespace
   8 from idl_node import IDLNode
   9 from idl_option import GetOption
  10 from idl_visitor import IDLVisitor
  11 from idl_release import IDLReleaseMap
  12
  13 #
  14 # IDLLabelResolver
  15 #
  16 # A specialized visitor which traverses the AST, building a mapping of
  17 # Release names to Versions numbers and calculating a min version.
  18 # The mapping is applied to the File nodes within the AST.
  19 #
  20 class IDLLabelResolver(IDLVisitor):
  21   def Depart(self, node, ignore, childdata):
  22     # Build list of Release=Version
  23     if node.IsA('LabelItem'):
  24       channel = node.GetProperty('channel')
  25       if not channel:
  26         channel = 'stable'
  27       return (node.GetName(), node.GetProperty('VALUE'), channel)
  28
  29     # On completion of the Label, apply to the parent File if the
  30     # name of the label matches the generation label.
  31     if node.IsA('Label') and node.GetName() == GetOption('label'):
  32       try:
  33         node.parent.release_map = IDLReleaseMap(childdata)
  34       except Exception as err:
  35         node.Error('Unable to build release map: %s' % str(err))
  36
  37     # For File objects, set the minimum version
  38     if node.IsA('File'):
  39       file_min, _ = node.release_map.GetReleaseRange()
  40       node.SetMin(file_min)
  41
  42     return None
  43
  44
  45 #
  46 # IDLNamespaceVersionResolver
  47 #
  48 # A specialized visitor which traverses the AST, building a namespace tree
  49 # as it goes.  The namespace tree is mapping from a name to a version list.
  50 # Labels must already be resolved to use.
  51 #
  52 class IDLNamespaceVersionResolver(IDLVisitor):
  53   NamespaceSet = set(['AST', 'Callspec', 'Interface', 'Member', 'Struct'])
  54   #
  55   # When we arrive at a node we must assign it a namespace and if the
  56   # node is named, then place it in the appropriate namespace.
  57   #
  58   def Arrive(self, node, parent_namespace):
  59     # If we are a File, grab the Min version and replease mapping
  60     if node.IsA('File'):
  61       self.rmin = node.GetMinMax()[0]
  62       self.release_map = node.release_map
  63
  64     # Set the min version on any non Label within the File
  65     if not node.IsA('AST', 'File', 'Label', 'LabelItem'):
  66       my_min, _ = node.GetMinMax()
  67       if not my_min:
  68         node.SetMin(self.rmin)
  69
  70     # If this object is not a namespace aware object, use the parent's one
  71     if node.cls not in self.NamespaceSet:
  72       node.namespace = parent_namespace
  73     else:
  74     # otherwise create one.
  75       node.namespace = IDLNamespace(parent_namespace)
  76
  77     # If this node is named, place it in its parent's namespace
  78     if parent_namespace and node.cls in IDLNode.NamedSet:
  79       # Set version min and max based on properties
  80       if self.release_map:
  81         vmin = node.GetProperty('dev_version')
  82         if vmin == None:
  83           vmin = node.GetProperty('version')
  84         vmax = node.GetProperty('deprecate')
  85         # If no min is available, the use the parent File's min
  86         if vmin == None:
  87           rmin = self.rmin
  88         else:
  89           rmin = self.release_map.GetRelease(vmin)
  90         rmax = self.release_map.GetRelease(vmax)
  91         node.SetReleaseRange(rmin, rmax)
  92       parent_namespace.AddNode(node)
  93
  94     # Pass this namespace to each child in case they inherit it
  95     return node.namespace
  96
  97
  98 #
  99 # IDLFileTypeRessolver
 100 #
 101 # A specialized visitor which traverses the AST and sets a FILE property
 102 # on all file nodes.  In addition, searches the namespace resolving all
 103 # type references.  The namespace tree must already have been populated
 104 # before this visitor is used.
 105 #
 106 class IDLFileTypeResolver(IDLVisitor):
 107   def VisitFilter(self, node, data):
 108     return not node.IsA('Comment', 'Copyright')
 109
 110   def Arrive(self, node, filenode):
 111     # Track the file node to update errors
 112     if node.IsA('File'):
 113       node.SetProperty('FILE', node)
 114       filenode = node
 115
 116     if not node.IsA('AST'):
 117       file_min, _ = filenode.release_map.GetReleaseRange()
 118       if not file_min:
 119         print 'Resetting min on %s to %s' % (node, file_min)
 120         node.SetMinRange(file_min)
 121
 122     # If this node has a TYPEREF, resolve it to a version list
 123     typeref = node.GetPropertyLocal('TYPEREF')
 124     if typeref:
 125       node.typelist = node.parent.namespace.FindList(typeref)
 126       if not node.typelist:
 127         node.Error('Could not resolve %s.' % typeref)
 128     else:
 129       node.typelist = None
 130     return filenode
 131
 132 #
 133 # IDLReleaseResolver
 134 #
 135 # A specialized visitor which will traverse the AST, and generate a mapping
 136 # from any release to the first release in which that version of the object
 137 # was generated.  Types must already be resolved to use.
 138 #
 139 class IDLReleaseResolver(IDLVisitor):
 140   def Arrive(self, node, releases):
 141     node.BuildReleaseMap(releases)
 142     return releases
 143
 144
 145 #
 146 # IDLAst
 147 #
 148 # A specialized version of the IDLNode for containing the whole of the
 149 # AST.  Construction of the AST object will cause resolution of the
 150 # tree including versions, types, etc...  Errors counts will be collected
 151 # both per file, and on the AST itself.
 152 #
 153 class IDLAst(IDLNode):
 154   def __init__(self, children):
 155     IDLNode.__init__(self, 'AST', 'BuiltIn', 1, 0, children)
 156     self.Resolve()
 157
 158   def Resolve(self):
 159     # Set the appropriate Release=Version mapping for each File
 160     IDLLabelResolver().Visit(self, None)
 161
 162     # Generate the Namesapce Tree
 163     self.namespace = IDLNamespace(None)
 164     IDLNamespaceVersionResolver().Visit(self, self.namespace)
 165
 166     # Using the namespace, resolve type references
 167     IDLFileTypeResolver().Visit(self, None)
 168
 169     # Build an ordered list of all releases
 170     releases = set()
 171     for filenode in self.GetListOf('File'):
 172       releases |= set(filenode.release_map.GetReleases())
 173
 174     # Generate a per node list of releases and release mapping
 175     IDLReleaseResolver().Visit(self, sorted(releases))
 176
 177     for filenode in self.GetListOf('File'):
 178       errors = filenode.GetProperty('ERRORS')
 179       if errors:
 180         self.errors += errors
 181
 182