IDL parser rewrite in Python

Source/bindings/scripts/interface_dependency_resolver.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 17 matching lines @@
 
 """Resolve interface dependencies, producing a merged IdlDefinitions object.
 
 This library computes interface dependencies (partial interfaces and
 implements), reads the dependency files, and merges them to the IdlDefinitions
 for the main IDL file, producing an IdlDefinitions object representing the
 entire interface.
 
 It also checks whether a file should have bindings generated, or whether
 instead it is just a dependency.
-
-FIXME: Currently a stub, as part of landing the parser incrementally.
-Just computes dependencies, and should always return None, indicating
-bindings should not be generated.
-Does not read IDL files or merge IdlDefinitions yet.
 """
 
 import os.path
 
+import idl_reader
 
-def merge_interface_dependencies(idl_definitions, idl_filename, interface_dependencies_filename, additional_idl_filenames):
+
+class InterfaceNotFoundError(Exception):
+    """Raised if (partial) interface not found in target."""
+    pass
+
+
+class InvalidPartialInterfaceError(Exception):
+    """Raised if a file listed as a partial interface is not in fact so."""
+    pass
+
+
+def merge_dependencies(definitions, idl_filename, interface_dependencies_filename, additional_idl_filenames, verbose=False):
     """Merges dependencies into an existing IDL document.
 
-    Modifies idl_definitions in place by adding parsed dependencies, and checks
+    Modifies definitions in place by adding parsed dependencies, and checks
     whether bindings should be generated, returning bool.
 
-    FIXME: stub: parser not implemented yet
-
     Arguments:
-        idl_definitions: IdlDefinitions object, modified in place
+        definitions: IdlDefinitions object, modified in place
         idl_filename: filename of main IDL file for the interface
         interface_dependencies_file: filename of dependencies file (produced by compute_dependencies.py)
         additional_idl_files: list of additional files, not listed in interface_dependencies_file, for which bindings should nonetheless be generated
     Returns:
         bool, whether bindings should be generated or not.
     """
     basename = os.path.basename(idl_filename)
     interface_name, _ = os.path.splitext(basename)
 
     dependency_idl_filenames = compute_dependency_idl_files(basename, interface_dependencies_filename, additional_idl_filenames)
     if dependency_idl_filenames is None:
         return False
-    # FIXME: currently dependency_idl_files *must* be None (indicating that
-    # dummy .cpp and .h files should be generated), as actual parser not
-    # present yet.
-    raise RuntimeError('Stub: parser not implemented yet')
+    # The Blink IDL filenaming convention is that the file <interface_name>.idl
+    # MUST contain the interface "interface_name" or exception "interface_name".
+    if interface_name in definitions.exceptions:
+        # Exceptions do not have dependencies, so no merging necessary
+        return definitions
+    try:
+        interface = definitions.interfaces[interface_name]
+    except KeyError:
+        raise InterfaceNotFoundError('Could not find interface or exception "{interface_name}" in {basename}'.format(**locals()))
+    merge_interface_dependencies(interface, idl_filename, dependency_idl_filenames, verbose=verbose)
+
+    return definitions
 
 
 def compute_dependency_idl_files(target_idl_basename, interface_dependencies_filename, additional_idl_filenames):
     """Returns list of IDL file dependencies for a given main IDL file.
 
     - Returns a list of IDL files on which a given IDL file depends,
       possibly empty.
       Dependencies consist of partial interface files and files for other
       interfaces that the given interface implements.
     - Returns an empty list also if the given IDL file is an additional IDL
@@ skipping 30 matching lines @@
                 return dependency_filenames.split()
 
     # additional_idl_files is a list of IDL files which should not be included
     # in DerivedSources*.cpp, and hence are not listed in the interface
     # dependencies file, but for which we should generate .cpp and .h files.
     additional_idl_basenames = set(map(os.path.basename, additional_idl_filenames))
     if target_idl_basename in additional_idl_basenames:
         return []
 
     return None
+
+
+def merge_interface_dependencies(interface, idl_filename, dependency_idl_filenames, verbose=False):
+    """Merge partial interfaces in supplementary_idl_files into target_document.
+
+    No return: modifies target_document in place.
+    """
+    # Sort so order consistent, so can compare output from run to run.
+    for dependency_idl_filename in sorted(dependency_idl_filenames):
+        dependency_interface_name, _ = os.path.splitext(os.path.basename(dependency_idl_filename))
+        definitions = idl_reader.read_idl_file(dependency_idl_filename, verbose=verbose)
+
+        for dependency_interface in definitions.interfaces.itervalues():
+            # Supplemental files contain either partial interfaces for
+            # the (single) target interface, in which case the interface names
+            # must agree, or interfaces that are implemented by the target
+            # interface, in which case the interface names differ.
+            if dependency_interface.is_partial and dependency_interface.name != interface.name:
+                raise InvalidPartialInterfaceError('%s is not a partial interface of %s. There maybe a bug in the the dependency generator (compute_depedencies.py).' % (dependency_idl_filename, idl_filename))
+            if 'ImplementedAs' in dependency_interface.extended_attributes:
+                del dependency_interface.extended_attributes['ImplementedAs']
+            merge_dependency_interface(interface, dependency_interface, dependency_interface_name)
+
+
+def merge_dependency_interface(interface, dependency_interface, dependency_interface_name):
+    """Merge dependency_interface into interface.
+
+    No return: modifies interface in place.
+    """
+    def merge_lists(source_list, target_list):
+        for element in source_list:
+            if dependency_interface.is_partial:
+                element.extended_attributes['ImplementedBy'] = dependency_interface_name
+            element.extended_attributes.update(dependency_interface.extended_attributes)
+            target_list.append(element)
+
+    merge_lists(dependency_interface.attributes, interface.attributes)
+    merge_lists(dependency_interface.constants, interface.constants)
+    merge_lists(dependency_interface.functions, interface.functions)