mojo/public/tools/bindings/generators/mojom_js_generator.py

   1 # Copyright 2013 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 """Generates JavaScript source files from a mojom.Module."""
   6
   7 import mojom.generate.generator as generator
   8 import mojom.generate.module as mojom
   9 import mojom.generate.pack as pack
  10 from mojom.generate.template_expander import UseJinja
  11
  12 _kind_to_javascript_default_value = {
  13   mojom.BOOL:         "false",
  14   mojom.INT8:         "0",
  15   mojom.UINT8:        "0",
  16   mojom.INT16:        "0",
  17   mojom.UINT16:       "0",
  18   mojom.INT32:        "0",
  19   mojom.UINT32:       "0",
  20   mojom.FLOAT:        "0",
  21   mojom.HANDLE:       "null",
  22   mojom.DCPIPE:       "null",
  23   mojom.DPPIPE:       "null",
  24   mojom.MSGPIPE:      "null",
  25   mojom.SHAREDBUFFER: "null",
  26   mojom.INT64:        "0",
  27   mojom.UINT64:       "0",
  28   mojom.DOUBLE:       "0",
  29   mojom.STRING:       '""',
  30 }
  31
  32
  33 def JavaScriptDefaultValue(field):
  34   if field.default:
  35     if isinstance(field.kind, mojom.Struct):
  36       assert field.default == "default"
  37       return "new %s()" % JavascriptType(field.kind)
  38     return ExpressionToText(field.default)
  39   if field.kind in mojom.PRIMITIVES:
  40     return _kind_to_javascript_default_value[field.kind]
  41   if isinstance(field.kind, mojom.Struct):
  42     return "null"
  43   if isinstance(field.kind, mojom.Array):
  44     return "null"
  45   if isinstance(field.kind, mojom.Interface) or \
  46      isinstance(field.kind, mojom.InterfaceRequest):
  47     return _kind_to_javascript_default_value[mojom.MSGPIPE]
  48   if isinstance(field.kind, mojom.Enum):
  49     return "0"
  50
  51
  52 def JavaScriptPayloadSize(packed):
  53   packed_fields = packed.packed_fields
  54   if not packed_fields:
  55     return 0
  56   last_field = packed_fields[-1]
  57   offset = last_field.offset + last_field.size
  58   pad = pack.GetPad(offset, 8)
  59   return offset + pad
  60
  61
  62 _kind_to_codec_type = {
  63   mojom.BOOL:         "codec.Uint8",
  64   mojom.INT8:         "codec.Int8",
  65   mojom.UINT8:        "codec.Uint8",
  66   mojom.INT16:        "codec.Int16",
  67   mojom.UINT16:       "codec.Uint16",
  68   mojom.INT32:        "codec.Int32",
  69   mojom.UINT32:       "codec.Uint32",
  70   mojom.FLOAT:        "codec.Float",
  71   mojom.HANDLE:       "codec.Handle",
  72   mojom.DCPIPE:       "codec.Handle",
  73   mojom.DPPIPE:       "codec.Handle",
  74   mojom.MSGPIPE:      "codec.Handle",
  75   mojom.SHAREDBUFFER: "codec.Handle",
  76   mojom.INT64:        "codec.Int64",
  77   mojom.UINT64:       "codec.Uint64",
  78   mojom.DOUBLE:       "codec.Double",
  79   mojom.STRING:       "codec.String",
  80 }
  81
  82
  83 def CodecType(kind):
  84   if kind in mojom.PRIMITIVES:
  85     return _kind_to_codec_type[kind]
  86   if isinstance(kind, mojom.Struct):
  87     return "new codec.PointerTo(%s)" % CodecType(kind.name)
  88   if isinstance(kind, mojom.Array):
  89     return "new codec.ArrayOf(%s)" % CodecType(kind.kind)
  90   if isinstance(kind, mojom.Interface) or \
  91      isinstance(kind, mojom.InterfaceRequest):
  92     return CodecType(mojom.MSGPIPE)
  93   if isinstance(kind, mojom.Enum):
  94     return _kind_to_codec_type[mojom.INT32]
  95   return kind
  96
  97
  98 def JavaScriptDecodeSnippet(kind):
  99   if kind in mojom.PRIMITIVES:
 100     return "decodeStruct(%s)" % CodecType(kind)
 101   if isinstance(kind, mojom.Struct):
 102     return "decodeStructPointer(%s)" % CodecType(kind.name)
 103   if isinstance(kind, mojom.Array):
 104     return "decodeArrayPointer(%s)" % CodecType(kind.kind)
 105   if isinstance(kind, mojom.Interface) or \
 106      isinstance(kind, mojom.InterfaceRequest):
 107     return JavaScriptDecodeSnippet(mojom.MSGPIPE)
 108   if isinstance(kind, mojom.Enum):
 109     return JavaScriptDecodeSnippet(mojom.INT32)
 110
 111
 112 def JavaScriptEncodeSnippet(kind):
 113   if kind in mojom.PRIMITIVES:
 114     return "encodeStruct(%s, " % CodecType(kind)
 115   if isinstance(kind, mojom.Struct):
 116     return "encodeStructPointer(%s, " % CodecType(kind.name)
 117   if isinstance(kind, mojom.Array):
 118     return "encodeArrayPointer(%s, " % CodecType(kind.kind)
 119   if isinstance(kind, mojom.Interface) or \
 120      isinstance(kind, mojom.InterfaceRequest):
 121     return JavaScriptEncodeSnippet(mojom.MSGPIPE)
 122   if isinstance(kind, mojom.Enum):
 123     return JavaScriptEncodeSnippet(mojom.INT32)
 124
 125
 126 def TranslateConstants(token):
 127   if isinstance(token, (mojom.EnumValue, mojom.NamedValue)):
 128     # Both variable and enum constants are constructed like:
 129     # NamespaceUid.Struct[.Enum].CONSTANT_NAME
 130     name = []
 131     if token.imported_from:
 132       name.append(token.imported_from["unique_name"])
 133     if token.parent_kind:
 134       name.append(token.parent_kind.name)
 135     if isinstance(token, mojom.EnumValue):
 136       name.append(token.enum_name)
 137     name.append(token.name)
 138     return ".".join(name)
 139   return token
 140
 141
 142 def ExpressionToText(value):
 143   return TranslateConstants(value)
 144
 145
 146 def JavascriptType(kind):
 147   if kind.imported_from:
 148     return kind.imported_from["unique_name"] + "." + kind.name
 149   return kind.name
 150
 151
 152 class Generator(generator.Generator):
 153
 154   js_filters = {
 155     "default_value": JavaScriptDefaultValue,
 156     "payload_size": JavaScriptPayloadSize,
 157     "decode_snippet": JavaScriptDecodeSnippet,
 158     "encode_snippet": JavaScriptEncodeSnippet,
 159     "expression_to_text": ExpressionToText,
 160     "js_type": JavascriptType,
 161     "stylize_method": generator.StudlyCapsToCamel,
 162   }
 163
 164   @UseJinja("js_templates/module.js.tmpl", filters=js_filters)
 165   def GenerateJsModule(self):
 166     return {
 167       "namespace": self.module.namespace,
 168       "imports": self.GetImports(),
 169       "kinds": self.module.kinds,
 170       "enums": self.module.enums,
 171       "module": self.module,
 172       "structs": self.GetStructs() + self.GetStructsFromMethods(),
 173       "interfaces": self.module.interfaces,
 174     }
 175
 176   def GenerateFiles(self, args):
 177     self.Write(self.GenerateJsModule(), "%s.js" % self.module.name)
 178
 179   def GetImports(self):
 180     # Since each import is assigned a variable in JS, they need to have unique
 181     # names.
 182     counter = 1
 183     for each in self.module.imports:
 184       each["unique_name"] = "import" + str(counter)
 185       counter += 1
 186     return self.module.imports