Roll IDL to Dartium37 (r181268)

bindings/scripts/compute_interfaces_info_overall.py

+#!/usr/bin/python
+#
+# 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
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Compute global interface information, including public information, dependencies, and inheritance.
+
+Computed data is stored in a global variable, |interfaces_info|, and written as
+output (concretely, exported as a pickle). This is then used by the IDL compiler
+itself, so it does not need to compute global information itself, and so that
+inter-IDL dependencies are clear, since they are all computed here.
+
+The |interfaces_info| pickle is a *global* dependency: any changes cause a full
+rebuild. This is to avoid having to compute which public data is visible by
+which IDL files on a file-by-file basis, which is very complex for little
+benefit.
+|interfaces_info| should thus only contain data about an interface that
+contains paths or is needed by *other* interfaces, e.g., path data (to abstract
+the compiler from OS-specific file paths) or public data (to avoid having to
+read other interfaces unnecessarily).
+It should *not* contain full information about an interface (e.g., all
+extended attributes), as this would cause unnecessary rebuilds.
+
+|interfaces_info| is a dict, keyed by |interface_name|.
+
+Current keys are:
+* dependencies:
+    'implements_interfaces': targets of 'implements' statements
+    'referenced_interfaces': reference interfaces that are introspected
+                             (currently just targets of [PutForwards])
+
+* inheritance:
+    'ancestors': all ancestor interfaces
+    'inherited_extended_attributes': inherited extended attributes
+                                     (all controlling memory management)
+
+* public:
+    'is_callback_interface': bool, callback interface or not
+    'implemented_as': value of [ImplementedAs=...] on interface (C++ class name)
+
+* paths:
+    'full_path': path to the IDL file, so can lookup an IDL by interface name
+    'include_path': path for use in C++ #include directives
+    'dependencies_full_paths': paths to dependencies (for merging into main)
+    'dependencies_include_paths': paths for use in C++ #include directives
+
+Note that all of these are stable information, unlikely to change without
+moving or deleting files (hence requiring a full rebuild anyway) or significant
+code changes (for inherited extended attributes).
+
+Design doc: http://www.chromium.org/developers/design-documents/idl-build
+"""
+
+from collections import defaultdict
+import cPickle as pickle
+import optparse
+import sys
+
+from utilities import read_pickle_files, write_pickle_file
+
+INHERITED_EXTENDED_ATTRIBUTES = set([
+    'ActiveDOMObject',
+    'DependentLifetime',
+    'GarbageCollected',
+    'WillBeGarbageCollected',
+])
+
+# Main variable (filled in and exported)
+interfaces_info = {}
+
+# Auxiliary variables (not visible to future build steps)
+partial_interface_files = defaultdict(lambda: {
+    'full_paths': [],
+    'include_paths': [],
+})
+parent_interfaces = {}
+inherited_extended_attributes_by_interface = {}  # interface name -> extended attributes
+
+
+class IdlInterfaceFileNotFoundError(Exception):
+    """Raised if the IDL file implementing an interface cannot be found."""
+    pass
+
+
+def parse_options():
+    usage = 'Usage: %prog [InfoIndividual.pickle]... [Info.pickle]'
+    parser = optparse.OptionParser(usage=usage)
+    parser.add_option('--write-file-only-if-changed', type='int', help='if true, do not write an output file if it would be identical to the existing one, which avoids unnecessary rebuilds in ninja')
+
+    options, args = parser.parse_args()
+    if options.write_file_only_if_changed is None:
+        parser.error('Must specify whether file is only written if changed using --write-file-only-if-changed.')
+    options.write_file_only_if_changed = bool(options.write_file_only_if_changed)
+    return options, args
+
+
+def dict_of_dicts_of_lists_update_or_append(existing, other):
+    """Updates an existing dict of dicts of lists, or appends to lists if key already present.
+
+    Needed for merging partial_interface_files across components.
+    """
+    for key, value in other.iteritems():
+        if key not in existing:
+            existing[key] = value
+            continue
+        existing_value = existing[key]
+        for inner_key, inner_value in value.iteritems():
+            existing_value[inner_key].extend(inner_value)
+
+
+################################################################################
+# Computations
+################################################################################
+
+def compute_inheritance_info(interface_name):
+    """Compute inheritance information, namely ancestors and inherited extended attributes."""
+    def generate_ancestors(interface_name):
+        while interface_name in parent_interfaces:
+            interface_name = parent_interfaces[interface_name]
+            yield interface_name
+
+    ancestors = list(generate_ancestors(interface_name))
+    inherited_extended_attributes = inherited_extended_attributes_by_interface[interface_name]
+    for ancestor in ancestors:
+        # Ancestors may not be present, notably if an ancestor is a generated
+        # IDL file and we are running this script from run-bindings-tests,
+        # where we don't generate these files.
+        ancestor_extended_attributes = inherited_extended_attributes_by_interface.get(ancestor, {})
+        inherited_extended_attributes.update(ancestor_extended_attributes)
+
+    interfaces_info[interface_name].update({
+        'ancestors': ancestors,
+        'inherited_extended_attributes': inherited_extended_attributes,
+    })
+
+
+def compute_interfaces_info_overall(info_individuals):
+    """Compute information about IDL files.
+
+    Information is stored in global interfaces_info.
+    """
+    for info in info_individuals:
+        # No overlap between interface names, so ok to use dict.update
+        interfaces_info.update(info['interfaces_info'])
+        # Interfaces in one component may have partial interfaces in
+        # another component. This is ok (not a layering violation), since
+        # partial interfaces are used to *extend* interfaces.
+        # We thus need to update or append if already present
+        dict_of_dicts_of_lists_update_or_append(
+                partial_interface_files, info['partial_interface_files'])
+
+    # Record inheritance information individually
+    for interface_name, interface_info in interfaces_info.iteritems():
+        extended_attributes = interface_info['extended_attributes']
+        inherited_extended_attributes_by_interface[interface_name] = dict(
+                (key, value)
+                for key, value in extended_attributes.iteritems()
+                if key in INHERITED_EXTENDED_ATTRIBUTES)
+        parent = interface_info['parent']
+        if parent:
+            parent_interfaces[interface_name] = parent
+
+    # Once all individual files handled, can compute inheritance information
+    # and dependencies
+
+    # Compute inheritance info
+    for interface_name in interfaces_info:
+        compute_inheritance_info(interface_name)
+
+    # Compute dependencies
+    # Move implements info from implement*ed* interface (rhs of 'implements')
+    # to implement*ing* interface (lhs of 'implements').
+    # Note that moving an 'implements' statement between implementing and
+    # implemented files does not change the info (or hence cause a rebuild)!
+    for right_interface_name, interface_info in interfaces_info.iteritems():
+        for left_interface_name in interface_info['implemented_by_interfaces']:
+            interfaces_info[left_interface_name]['implements_interfaces'].append(right_interface_name)
+        del interface_info['implemented_by_interfaces']
+
+    # An IDL file's dependencies are partial interface files that extend it,
+    # and files for other interfaces that this interfaces implements.
+    for interface_name, interface_info in interfaces_info.iteritems():
+        partial_interface_paths = partial_interface_files[interface_name]
+        partial_interfaces_full_paths = partial_interface_paths['full_paths']
+        # Partial interface definitions each need an include, as they are
+        # implemented in separate classes from the main interface.
+        partial_interfaces_include_paths = partial_interface_paths['include_paths']
+
+        implemented_interfaces = interface_info['implements_interfaces']
+        try:
+            implemented_interfaces_info = [
+                interfaces_info[interface]
+                for interface in implemented_interfaces]
+        except KeyError as key_name:
+            raise IdlInterfaceFileNotFoundError('Could not find the IDL file where the following implemented interface is defined: %s' % key_name)
+        implemented_interfaces_full_paths = [
+            implemented_interface_info['full_path']
+            for implemented_interface_info in implemented_interfaces_info]
+        # Implemented interfaces don't need includes, as this is handled in
+        # the Blink implementation (they are implemented on |impl| itself,
+        # hence header is included in implementing class).
+        # However, they are needed for legacy implemented interfaces that
+        # are being treated as partial interfaces, until we remove these.
+        # http://crbug.com/360435
+        implemented_interfaces_include_paths = [
+            implemented_interface_info['include_path']
+            for implemented_interface_info in implemented_interfaces_info
+            if implemented_interface_info['is_legacy_treat_as_partial_interface']]
+
+        interface_info.update({
+            'dependencies_full_paths': (partial_interfaces_full_paths +
+                                        implemented_interfaces_full_paths),
+            'dependencies_include_paths': (partial_interfaces_include_paths +
+                                           implemented_interfaces_include_paths),
+        })
+
+    # Clean up temporary private information
+    for interface_info in interfaces_info.itervalues():
+        del interface_info['extended_attributes']
+        del interface_info['is_legacy_treat_as_partial_interface']
+        del interface_info['parent']
+
+
+################################################################################
+
+def main():
+    options, args = parse_options()
+    # args = Input1, Input2, ..., Output
+    interfaces_info_filename = args.pop()
+    info_individuals = read_pickle_files(args)
+
+    compute_interfaces_info_overall(info_individuals)
+    write_pickle_file(interfaces_info_filename,
+                      interfaces_info,
+                      options.write_file_only_if_changed)
+
+
+if __name__ == '__main__':
+    sys.exit(main())