[privacy_budget] Fix UseCounter name calculation

Blink bindings generate use counter names in several locations. This
change updates the name calculation logic to match what's used in
generating the web_feature.mojom file.

In addition, the change also introduces logic to perform a rudimentary
parse step on the web_feature.mojom file and extract the feature value
constants. These are the values that will be used eventually for
locating usage metrics for identifiable APIs.

Bug: 1144960
Change-Id: Id40ccab032f1fb04e1c06bd763847f73180df8a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2552722Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: Asanka Herath <asanka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833744}

tools/privacy_budget/blink_apis/BUILD.gn

@@ -20,7 +20,8 @@ action("blink_apis") {
   inputs = [
     web_idl_database_filepath,
     "blink_api_proto.py",
-    "generate_blink_api_db.py"
+    "generate_blink_api_db.py",
+    "web_feature.py",
   ]
   output_data_file = "${root_build_dir}/blink_apis.textpb"
   outputs = [ output_data_file ]
@@ -30,6 +31,10 @@ action("blink_apis") {
     rebase_path(web_idl_database_filepath, root_build_dir),
     "--output",
     rebase_path(output_data_file, root_build_dir),
+    "--web_feature_mojom",
+    rebase_path(
+        "//third_party/blink/public/mojom/web_feature/web_feature.mojom",
+        root_build_dir),
     "--path",
     string_join(":",
                 [

tools/privacy_budget/blink_apis/blink_api_proto.py

@@ -14,10 +14,13 @@ class BlinkApiProto(object):
     """BlinkApiProto converts a WebIdlDatabase to
     a identifiability.blink_apis.Snapshot proto defined in
     proto/blink_apis.proto"""
-    def __init__(self, web_idl_pickle, proto_out_file, chromium_revision):
+
+    def __init__(self, web_idl_pickle, proto_out_file, chromium_revision,
+                 web_features):
         self.web_idl_database = web_idl.Database.read_from_file(web_idl_pickle)
         self.proto_out_file = proto_out_file
         self.snapshot = pb.Snapshot()
+        self.web_features = web_features
         if chromium_revision:
             self.snapshot.chromium_revision = chromium_revision
 
@@ -41,7 +44,7 @@ class BlinkApiProto(object):
 
         for function in self.web_idl_database.callback_functions:
             self._ConvertIdlOperation(self.snapshot.callback_functions.add(),
-                                      function)
+                                      function, None)
 
         for interface in self.web_idl_database.callback_interfaces:
             self._ConvertIdlInterfaceLike(
@@ -64,22 +67,43 @@ class BlinkApiProto(object):
             return pb.HIGH_ENTROPY_DIRECT
         assert False, "Unknown HighEntropy value {}".format(val)
 
-    def _GetUseCounter(self, parent, measure, measure_as):
-        if measure_as:
-            return measure_as.value
-        if measure:
-            use_counter = capitalize(parent.identifier)
-            if not isinstance(parent, web_idl.Interface):
-                use_counter = (capitalize(parent.owner.identifier) + '_' +
-                               use_counter)
-            return use_counter
-        return None
+    def _GetUseCounter(self, member, parent, ext_attrs):
+        assert isinstance(ext_attrs, web_idl.ExtendedAttributes)
+        assert parent is None or hasattr(parent, 'identifier')
+
+        if 'MeasureAs' in ext_attrs:
+            return ext_attrs.value_of('MeasureAs')
+
+        if 'Measure' not in ext_attrs:
+            return None
+
+        if parent is not None:
+            prefix = '%s_%s' % (capitalize(
+                parent.identifier), capitalize(member.identifier))
+        else:
+            prefix = capitalize(member.identifier)
+
+        suffix = ""
+        if isinstance(member, web_idl.FunctionLike):
+            if len(member.arguments) == 0 and member.is_getter:
+                suffix = "AttributeGetter"
+            elif len(member.arguments) == 1 and member.is_setter:
+                suffix = "AttributeSetter"
+            else:
+                suffix = "Method"
+        elif isinstance(member, web_idl.Attribute):
+            suffix = "AttributeGetter"
+        else:
+            assert False, repr(member)
+
+        return "V8" + prefix + "_" + suffix
 
     def _ConvertIdlType(self, dest, idl_type):
         assert isinstance(idl_type, web_idl.IdlType)
 
         dest.idl_type_string = idl_type.type_name_without_extended_attributes
-        self._ConvertExtendedAttributes(dest.extended_attributes, idl_type)
+        self._ConvertExtendedAttributes(dest.extended_attributes, idl_type,
+                                        None)
 
         # Only look at named definitions. Simple, primitive types don't define
         # named identifiers.
@@ -96,8 +120,8 @@ class BlinkApiProto(object):
         depends_on.remove(idl_type.type_name_without_extended_attributes)
         dest.depends_on[:] = list(depends_on)
 
-    def _ConvertExtendedAttributes(self, dest, parent):
-        attr = parent.extended_attributes
+    def _ConvertExtendedAttributes(self, dest, member, interface):
+        attr = member.extended_attributes
         assert isinstance(attr, web_idl.ExtendedAttributes)
         dest.cross_origin_isolated = ('CrossOriginIsolated' in attr)
         if 'Exposed' in attr:
@@ -111,25 +135,27 @@ class BlinkApiProto(object):
                 for v in exposed.values:
                     e = dest.exposed.add()
                     e.interface = v
-                    e.member = parent.identifier
+                    e.member = member.identifier
 
         setattr(dest, 'global', ('Global' in attr))
         dest.same_object = ('SameObject' in attr)
         dest.secure_context = ('SecureContext' in attr)
         dest.high_entropy = self._GetHighEntropyType(attr.get('HighEntropy'))
         if 'Measure' in attr or 'MeasureAs' in attr:
-            dest.use_counter = self._GetUseCounter(parent, attr.get('Measure'),
-                                                   attr.get('MeasureAs'))
+            dest.use_counter = self._GetUseCounter(member, interface, attr)
+            dest.use_counter_feature_value = self.web_features[
+                dest.use_counter]
         if 'RuntimeEnabled' in attr:
             dest.runtime_enabled = attr.value_of('RuntimeEnabled')
         if 'ImplementedAs' in attr:
             dest.implemented_as = attr.value_of('ImplementedAs')
 
-    def _ConvertIdlAttribute(self, dest, attr):
+    def _ConvertIdlAttribute(self, dest, attr, interface):
         dest.name = attr.identifier
         dest.is_static = attr.is_static
         dest.is_readonly = attr.is_readonly
-        self._ConvertExtendedAttributes(dest.extended_attributes, attr)
+        self._ConvertExtendedAttributes(dest.extended_attributes, attr,
+                                        interface)
         self._ConvertIdlType(dest.idl_type, attr.idl_type)
         self._ConvertSourceLocation(dest.source_location, attr.debug_info)
 
@@ -144,12 +170,13 @@ class BlinkApiProto(object):
             return pb.SPECIAL_OP_STRINGIFIER
         return pb.SPECIAL_OP_UNSPECIFIED
 
-    def _ConvertIdlOperation(self, dest, op):
+    def _ConvertIdlOperation(self, dest, op, parent):
         dest.name = op.identifier
         dest.static = op.is_static
         dest.special_op_type = self._GetSpecialOperationType(op)
         self._ConvertIdlType(dest.return_type, op.return_type)
         self._ConvertSourceLocation(dest.source_location, op.debug_info)
+        self._ConvertExtendedAttributes(dest.extended_attributes, op, parent)
         for arg in op.arguments:
             self._ConvertIdlType(dest.arguments.add(), arg.idl_type)
 
@@ -158,30 +185,32 @@ class BlinkApiProto(object):
         dest.values[:] = enumer.values
         self._ConvertSourceLocation(dest.source_location, enumer.debug_info)
 
-    def _ConvertIdlConstant(self, dest, constant):
+    def _ConvertIdlConstant(self, dest, constant, parent):
         dest.name = constant.identifier
         dest.value = constant.value.literal
-        self._ConvertExtendedAttributes(dest.extended_attributes, constant)
+        self._ConvertExtendedAttributes(dest.extended_attributes, constant,
+                                        parent)
         self._ConvertIdlType(dest.idl_type, constant.idl_type)
         self._ConvertSourceLocation(dest.source_location, constant.debug_info)
 
-    def _ConvertIdlInterfaceLike(self, dest, interface):
-        dest.name = interface.identifier
-        if hasattr(interface, 'inherited') and interface.inherited:
-            dest.inherits_from = interface.inherited.identifier
-        self._ConvertExtendedAttributes(dest.extended_attributes, interface)
-        self._ConvertSourceLocation(dest.source_location, interface.debug_info)
-        for attr in interface.attributes:
-            self._ConvertIdlAttribute(dest.attributes.add(), attr)
-        for op in interface.operations:
-            self._ConvertIdlOperation(dest.operations.add(), op)
-        for constant in interface.constants:
-            self._ConvertIdlConstant(dest.constants.add(), constant)
-
-    def _ConvertDictionaryMember(self, dest, member):
+    def _ConvertIdlInterfaceLike(self, dest, parent):
+        dest.name = parent.identifier
+        if hasattr(parent, 'inherited') and parent.inherited:
+            dest.inherits_from = parent.inherited.identifier
+        self._ConvertExtendedAttributes(dest.extended_attributes, parent, None)
+        self._ConvertSourceLocation(dest.source_location, parent.debug_info)
+        for attr in parent.attributes:
+            self._ConvertIdlAttribute(dest.attributes.add(), attr, parent)
+        for op in parent.operations:
+            self._ConvertIdlOperation(dest.operations.add(), op, parent)
+        for constant in parent.constants:
+            self._ConvertIdlConstant(dest.constants.add(), constant, parent)
+
+    def _ConvertDictionaryMember(self, dest, member, interface):
         assert isinstance(member, web_idl.DictionaryMember)
         dest.name = member.identifier
-        self._ConvertExtendedAttributes(dest.extended_attributes, member)
+        self._ConvertExtendedAttributes(dest.extended_attributes, member,
+                                        interface)
         self._ConvertIdlType(dest.idl_type, member.idl_type)
         self._ConvertSourceLocation(dest.source_location, member.debug_info)
 
@@ -193,7 +222,8 @@ class BlinkApiProto(object):
         if dictionary.inherited:
             dest.inherits_from = dictionary.inherited.identifier
         for member in dictionary.members:
-            self._ConvertDictionaryMember(dest.members.add(), member)
+            self._ConvertDictionaryMember(dest.members.add(), member,
+                                          dictionary)
 
     def _ConvertIdlTypedef(self, dest, typedef):
         assert isinstance(typedef, web_idl.Typedef)
@@ -217,4 +247,5 @@ class BlinkApiProto(object):
 
         if source_file:
             dest.filename = source_file
+
             dest.line = line_no

tools/privacy_budget/blink_apis/generate_blink_api_db.py

@@ -17,7 +17,6 @@
 # >
 #
 # [VPYTHON:END]
-
 """
 Generate a database of Blink APIs.
 
@@ -51,39 +50,44 @@ import argparse
 
 
 def parse_options():
-  parser = argparse.ArgumentParser(description="%prog [options]")
-  parser.add_argument("--web_idl_database",
-                      type=str,
-                      help="filepath of the input database")
-  parser.add_argument("--output", type=str, help="filepath of output file")
-  parser.add_argument("--path", type=str, help="Additions to sys.path")
-  parser.add_argument(
-      "--chromium_revision",
-      type=str,
-      help="Chromium revision (git hash) for the source of Blink WebIDL DB")
-  args = parser.parse_args()
-
-  required_option_names = ("web_idl_database", "output")
-  for opt_name in required_option_names:
-    if getattr(args, opt_name) is None:
-      parser.error("--{} is a required option.".format(opt_name))
-
-  if args.path:
-    for p in args.path.split(':'):
-      sys.path.append(p)
-
-  return args
+    parser = argparse.ArgumentParser(description="%prog [options]")
+    parser.add_argument("--web_idl_database",
+                        type=str,
+                        help="filepath of the input database")
+    parser.add_argument("--web_feature_mojom",
+                        type=str,
+                        help="path of web_feature.mojom")
+    parser.add_argument("--output", type=str, help="filepath of output file")
+    parser.add_argument("--path", type=str, help="Additions to sys.path")
+    parser.add_argument(
+        "--chromium_revision",
+        type=str,
+        help="Chromium revision (git hash) for the source of Blink WebIDL DB")
+    args = parser.parse_args()
+
+    required_option_names = ("web_idl_database", "output", "web_feature_mojom")
+    for opt_name in required_option_names:
+        if getattr(args, opt_name) is None:
+            parser.error("--{} is a required option.".format(opt_name))
+
+    if args.path:
+        for p in args.path.split(':'):
+            sys.path.append(p)
+
+    return args
 
 
 def main():
-  args = parse_options()
+    args = parse_options()
 
-  from blink_api_proto import BlinkApiProto
-  p = BlinkApiProto(args.web_idl_database, args.output,
-                    args.chromium_revision)
-  p.Parse()
-  p.WriteTo(args.output)
+    from blink_api_proto import BlinkApiProto
+    from web_feature import WebFeature
+    w = WebFeature(args.web_feature_mojom)
+    p = BlinkApiProto(args.web_idl_database, args.output,
+                      args.chromium_revision, w)
+    p.Parse()
+    p.WriteTo(args.output)
 
 
 if __name__ == '__main__':
-  main()
+    main()

tools/privacy_budget/blink_apis/proto/blink_apis.proto

@@ -40,6 +40,7 @@ enum HighEntropyType {
 //
 // The latter are described in:
 // https://chromium.googlesource.com/chromium/src/+/master/third_party/blink/renderer/bindings/IDLExtendedAttributes.md
+// Next ID: 13
 message ExtendedAttributes {
   // https://heycam.github.io/webidl/#CrossOriginIsolated
   bool cross_origin_isolated = 1;
@@ -74,6 +75,9 @@ message ExtendedAttributes {
   // https://chromium.googlesource.com/chromium/src/+/master/third_party/blink/renderer/bindings/IDLExtendedAttributes.md#measure_i_m_a_c
   string use_counter = 7;
 
+  // The numeric value of the Use Counter feature constant.
+  int64 use_counter_feature_value = 12;
+
   // Value of [RuntimeEnabled]
   // https://chromium.googlesource.com/chromium/src/+/master/third_party/blink/renderer/bindings/IDLExtendedAttributes.md#runtimeenabled_i_m_a_c
   // Empty or undefined string is equivalent to there not being

tools/privacy_budget/blink_apis/web_feature.py

+# Copyright 2020 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import re
+
+
+class WebFeature(object):
+    def __init__(self, web_feature_path):
+        assert os.path.isfile(
+            web_feature_path), "%s not found" % (web_feature_path)
+
+        const_def = re.compile(r'\s*k(\w*)\s*=\s*(\d*)\s*,.*')
+
+        self.features = {}
+
+        with open(web_feature_path, 'r') as f:
+            for line in f.readlines():
+                match = const_def.match(line)
+                if match:
+                    self.features[match.group(1)] = int(match.group(2))
+
+    def __contains__(self, val):
+        return val in self.features
+
+    def __getitem__(self, val):
+        assert val in self, "%s not in mojom" % (val)
+        return self.features[val]