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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
5from code import Code
6from model import PropertyType
7import cpp_util
8from json_parse import OrderedDict
9import schema_util
10
11class _TypeDependency(object):
12  """Contains information about a dependency a namespace has on a type: the
13  type's model, and whether that dependency is "hard" meaning that it cannot be
14  forward declared.
15  """
16  def __init__(self, type_, hard=False):
17    self.type_ = type_
18    self.hard = hard
19
20  def GetSortKey(self):
21    return '%s.%s' % (self.type_.namespace.name, self.type_.name)
22
23
24class CppTypeGenerator(object):
25  """Manages the types of properties and provides utilities for getting the
26  C++ type out of a model.Property
27  """
28  def __init__(self, model, schema_loader, default_namespace=None):
29    """Creates a cpp_type_generator. The given root_namespace should be of the
30    format extensions::api::sub. The generator will generate code suitable for
31    use in the given model's namespace.
32    """
33    self._default_namespace = default_namespace
34    if self._default_namespace is None:
35      self._default_namespace = model.namespaces.values()[0]
36    self._schema_loader = schema_loader
37
38  def GetCppNamespaceName(self, namespace):
39    """Gets the mapped C++ namespace name for the given namespace relative to
40    the root namespace.
41    """
42    return namespace.unix_name
43
44  def GetNamespaceStart(self):
45    """Get opening self._default_namespace namespace declaration.
46    """
47    return Code().Append('namespace %s {' %
48        self.GetCppNamespaceName(self._default_namespace))
49
50  def GetNamespaceEnd(self):
51    """Get closing self._default_namespace namespace declaration.
52    """
53    return Code().Append('}  // %s' %
54        self.GetCppNamespaceName(self._default_namespace))
55
56  def GetEnumNoneValue(self, type_):
57    """Gets the enum value in the given model.Property indicating no value has
58    been set.
59    """
60    return '%s_NONE' % self.FollowRef(type_).unix_name.upper()
61
62  def GetEnumValue(self, type_, enum_value):
63    """Gets the enum value of the given model.Property of the given type.
64
65    e.g VAR_STRING
66    """
67    value = '%s_%s' % (self.FollowRef(type_).unix_name.upper(),
68                       cpp_util.Classname(enum_value.name.upper()))
69    # To avoid collisions with built-in OS_* preprocessor definitions, we add a
70    # trailing slash to enum names that start with OS_.
71    if value.startswith("OS_"):
72      value += "_"
73    return value
74
75  def GetCppType(self, type_, is_ptr=False, is_in_container=False):
76    """Translates a model.Property or model.Type into its C++ type.
77
78    If REF types from different namespaces are referenced, will resolve
79    using self._schema_loader.
80
81    Use |is_ptr| if the type is optional. This will wrap the type in a
82    scoped_ptr if possible (it is not possible to wrap an enum).
83
84    Use |is_in_container| if the type is appearing in a collection, e.g. a
85    std::vector or std::map. This will wrap it in the correct type with spacing.
86    """
87    cpp_type = None
88    if type_.property_type == PropertyType.REF:
89      ref_type = self._FindType(type_.ref_type)
90      if ref_type is None:
91        raise KeyError('Cannot find referenced type: %s' % type_.ref_type)
92      if self._default_namespace is ref_type.namespace:
93        cpp_type = ref_type.name
94      else:
95        cpp_type = '%s::%s' % (ref_type.namespace.unix_name, ref_type.name)
96    elif type_.property_type == PropertyType.BOOLEAN:
97      cpp_type = 'bool'
98    elif type_.property_type == PropertyType.INTEGER:
99      cpp_type = 'int'
100    elif type_.property_type == PropertyType.INT64:
101      cpp_type = 'int64'
102    elif type_.property_type == PropertyType.DOUBLE:
103      cpp_type = 'double'
104    elif type_.property_type == PropertyType.STRING:
105      cpp_type = 'std::string'
106    elif type_.property_type == PropertyType.ENUM:
107      cpp_type = cpp_util.Classname(type_.name)
108    elif type_.property_type == PropertyType.ANY:
109      cpp_type = 'base::Value'
110    elif (type_.property_type == PropertyType.OBJECT or
111          type_.property_type == PropertyType.CHOICES):
112      cpp_type = cpp_util.Classname(type_.name)
113    elif type_.property_type == PropertyType.FUNCTION:
114      # Functions come into the json schema compiler as empty objects. We can
115      # record these as empty DictionaryValues so that we know if the function
116      # was passed in or not.
117      cpp_type = 'base::DictionaryValue'
118    elif type_.property_type == PropertyType.ARRAY:
119      item_cpp_type = self.GetCppType(type_.item_type, is_in_container=True)
120      cpp_type = 'std::vector<%s>' % cpp_util.PadForGenerics(item_cpp_type)
121    elif type_.property_type == PropertyType.BINARY:
122      cpp_type = 'std::string'
123    else:
124      raise NotImplementedError('Cannot get type of %s' % type_.property_type)
125
126    # HACK: optional ENUM is represented elsewhere with a _NONE value, so it
127    # never needs to be wrapped in pointer shenanigans.
128    # TODO(kalman): change this - but it's an exceedingly far-reaching change.
129    if not self.FollowRef(type_).property_type == PropertyType.ENUM:
130      if is_in_container and (is_ptr or not self.IsCopyable(type_)):
131        cpp_type = 'linked_ptr<%s>' % cpp_util.PadForGenerics(cpp_type)
132      elif is_ptr:
133        cpp_type = 'scoped_ptr<%s>' % cpp_util.PadForGenerics(cpp_type)
134
135    return cpp_type
136
137  def IsCopyable(self, type_):
138    return not (self.FollowRef(type_).property_type in (PropertyType.ANY,
139                                                        PropertyType.ARRAY,
140                                                        PropertyType.OBJECT,
141                                                        PropertyType.CHOICES))
142
143  def GenerateForwardDeclarations(self):
144    """Returns the forward declarations for self._default_namespace.
145    """
146    c = Code()
147
148    for namespace, dependencies in self._NamespaceTypeDependencies().items():
149      c.Append('namespace %s {' % namespace.unix_name)
150      for dependency in dependencies:
151        # No point forward-declaring hard dependencies.
152        if dependency.hard:
153          continue
154        # Add more ways to forward declare things as necessary.
155        if dependency.type_.property_type in (PropertyType.CHOICES,
156                                              PropertyType.OBJECT):
157          c.Append('struct %s;' % dependency.type_.name)
158      c.Append('}')
159
160    return c
161
162  def GenerateIncludes(self, include_soft=False):
163    """Returns the #include lines for self._default_namespace.
164    """
165    c = Code()
166    for namespace, dependencies in self._NamespaceTypeDependencies().items():
167      for dependency in dependencies:
168        if dependency.hard or include_soft:
169          c.Append('#include "%s/%s.h"' % (namespace.source_file_dir,
170                                           namespace.unix_name))
171    return c
172
173  def _FindType(self, full_name):
174    """Finds the model.Type with name |qualified_name|. If it's not from
175    |self._default_namespace| then it needs to be qualified.
176    """
177    namespace = self._schema_loader.ResolveType(full_name,
178                                                self._default_namespace)
179    if namespace is None:
180      raise KeyError('Cannot resolve type %s. Maybe it needs a prefix '
181                     'if it comes from another namespace?' % full_name)
182    return namespace.types[schema_util.StripNamespace(full_name)]
183
184  def FollowRef(self, type_):
185    """Follows $ref link of types to resolve the concrete type a ref refers to.
186
187    If the property passed in is not of type PropertyType.REF, it will be
188    returned unchanged.
189    """
190    if type_.property_type != PropertyType.REF:
191      return type_
192    return self.FollowRef(self._FindType(type_.ref_type))
193
194  def _NamespaceTypeDependencies(self):
195    """Returns a dict ordered by namespace name containing a mapping of
196    model.Namespace to every _TypeDependency for |self._default_namespace|,
197    sorted by the type's name.
198    """
199    dependencies = set()
200    for function in self._default_namespace.functions.values():
201      for param in function.params:
202        dependencies |= self._TypeDependencies(param.type_,
203                                               hard=not param.optional)
204      if function.callback:
205        for param in function.callback.params:
206          dependencies |= self._TypeDependencies(param.type_,
207                                                 hard=not param.optional)
208    for type_ in self._default_namespace.types.values():
209      for prop in type_.properties.values():
210        dependencies |= self._TypeDependencies(prop.type_,
211                                               hard=not prop.optional)
212    for event in self._default_namespace.events.values():
213      for param in event.params:
214        dependencies |= self._TypeDependencies(param.type_,
215                                               hard=not param.optional)
216
217    # Make sure that the dependencies are returned in alphabetical order.
218    dependency_namespaces = OrderedDict()
219    for dependency in sorted(dependencies, key=_TypeDependency.GetSortKey):
220      namespace = dependency.type_.namespace
221      if namespace is self._default_namespace:
222        continue
223      if namespace not in dependency_namespaces:
224        dependency_namespaces[namespace] = []
225      dependency_namespaces[namespace].append(dependency)
226
227    return dependency_namespaces
228
229  def _TypeDependencies(self, type_, hard=False):
230    """Gets all the type dependencies of a property.
231    """
232    deps = set()
233    if type_.property_type == PropertyType.REF:
234      deps.add(_TypeDependency(self._FindType(type_.ref_type), hard=hard))
235    elif type_.property_type == PropertyType.ARRAY:
236      # Non-copyable types are not hard because they are wrapped in linked_ptrs
237      # when generated. Otherwise they're typedefs, so they're hard (though we
238      # could generate those typedefs in every dependent namespace, but that
239      # seems weird).
240      deps = self._TypeDependencies(type_.item_type,
241                                    hard=self.IsCopyable(type_.item_type))
242    elif type_.property_type == PropertyType.CHOICES:
243      for type_ in type_.choices:
244        deps |= self._TypeDependencies(type_, hard=self.IsCopyable(type_))
245    elif type_.property_type == PropertyType.OBJECT:
246      for p in type_.properties.values():
247        deps |= self._TypeDependencies(p.type_, hard=not p.optional)
248    return deps
249
250  def GeneratePropertyValues(self, property, line, nodoc=False):
251    """Generates the Code to display all value-containing properties.
252    """
253    c = Code()
254    if not nodoc:
255      c.Comment(property.description)
256
257    if property.value is not None:
258      c.Append(line % {
259          "type": self.GetCppType(property.type_),
260          "name": property.name,
261          "value": property.value
262        })
263    else:
264      has_child_code = False
265      c.Sblock('namespace %s {' % property.name)
266      for child_property in property.type_.properties.values():
267        child_code = self.GeneratePropertyValues(child_property,
268                                                 line,
269                                                 nodoc=nodoc)
270        if child_code:
271          has_child_code = True
272          c.Concat(child_code)
273      c.Eblock('}  // namespace %s' % property.name)
274      if not has_child_code:
275        c = None
276    return c
277