Add GetAvailableDocumentPolicyFeatures to feature_policy_helper.cc

This CL adds support for origin trials for document policy by adding
GetAvailableDocumentPolicyFeatures to feature_policy_helper.cc.

Potentially need to rename feature_policy_helper and
GetDefaultNameFeatureMap later.

Change-Id: I3f703c3d4f5a2c4f635b99839d06308a2c9eff6a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2008322Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Ian Clelland <iclelland@chromium.org>
Commit-Queue: Charlie Hu <chenleihu@google.com>
Cr-Commit-Position: refs/heads/master@{#737082}

third_party/blink/renderer/build/scripts/make_feature_policy_helper.py

@@ -13,46 +13,48 @@ class FeaturePolicyFeatureWriter(json5_generator.Writer):
 
     def __init__(self, json5_file_path, output_dir):
         super(FeaturePolicyFeatureWriter, self).__init__(json5_file_path, output_dir)
-        self._outputs = {
-            (self.file_basename + '.cc'): self.generate_implementation,
-        }
-
-        self._features = self.json5_file.name_dictionaries
-        # Set runtime and feature policy features
-        self._runtime_features = []
-        self._feature_policy_features = []
-        for feature in self._features:
+        runtime_features = []
+        feature_policy_features = []
+        # Note: there can be feature with same 'name' attribute in document_policy_features
+        # and in feature_policy_features. They are supposed to have the same 'depends_on' attribute.
+        # However, their feature_policy_name and document_policy_name might be different.
+        document_policy_features = []
+
+        for feature in self.json5_file.name_dictionaries:
             if feature['feature_policy_name']:
-                self._feature_policy_features.append(feature)
+                feature_policy_features.append(feature)
+            elif feature['document_policy_name']:
+                document_policy_features.append(feature)
             else:
-                self._runtime_features.append(feature)
-
-        origin_trials_set = origin_trials(self._runtime_features)
+                runtime_features.append(feature)
 
-        self._origin_trial_dependency_map = defaultdict(list)
-        self._runtime_to_feature_policy_map = defaultdict(list)
-        for feature in self._feature_policy_features:
+        origin_trials_set = origin_trials(runtime_features)
+        origin_trial_dependency_map = defaultdict(list)
+        runtime_to_feature_policy_map = defaultdict(list)
+        runtime_to_document_policy_map = defaultdict(list)
+        for feature in feature_policy_features + document_policy_features:
             for dependency in feature['depends_on']:
                 if str(dependency) in origin_trials_set:
-                    self._origin_trial_dependency_map[feature['name']].append(dependency)
+                    deps = origin_trial_dependency_map[feature['name']]
+                    if dependency not in deps:
+                        deps.append(dependency)
                 else:
-                    self._runtime_to_feature_policy_map[dependency].append(feature['name'])
-
-        self._header_guard = self.make_header_guard(self._relative_output_dir + self.file_basename + '.h')
-
-    def _template_inputs(self):
-        return {
-            'feature_policy_features': self._feature_policy_features,
-            'header_guard': self._header_guard,
-            'input_files': self._input_files,
-            'runtime_features': self._runtime_features,
-            'runtime_to_feature_policy_map': self._runtime_to_feature_policy_map,
-            'origin_trial_dependency_map': self._origin_trial_dependency_map,
-        }
+                    if feature['feature_policy_name']:
+                        runtime_to_feature_policy_map[dependency].append(feature['name'])
+                    else:
+                        runtime_to_document_policy_map[dependency].append(feature['name'])
 
-    @template_expander.use_jinja('templates/' + file_basename + '.cc.tmpl')
-    def generate_implementation(self):
-        return self._template_inputs()
+        self._outputs = {
+            self.file_basename + '.cc': template_expander.use_jinja('templates/' + self.file_basename + '.cc.tmpl')(lambda: {
+                'header_guard': self.make_header_guard(self._relative_output_dir + self.file_basename + '.h'),
+                'input_files': self._input_files,
+                'feature_policy_features': feature_policy_features,
+                'document_policy_features': document_policy_features,
+                'origin_trial_dependency_map': origin_trial_dependency_map,
+                'runtime_to_feature_policy_map': runtime_to_feature_policy_map,
+                'runtime_to_document_policy_map': runtime_to_document_policy_map
+            }),
+        }
 
 
 if __name__ == '__main__':

third_party/blink/renderer/build/scripts/templates/feature_policy_helper.cc.tmpl

@@ -37,9 +37,9 @@ const FeatureNameMap& GetDefaultFeatureNameMap() {
                                  mojom::FeaturePolicyFeature::k{{feature.name}});
     {% endif %}
     {% endfor %}
-    {% for runtime_feature_name, FP_features in runtime_to_feature_policy_map.items() | sort %}
+    {% for runtime_feature_name, dependent_features in runtime_to_feature_policy_map.items() | sort %}
     if (RuntimeEnabledFeatures::{{runtime_feature_name}}Enabled()) {
-      {% for feature in FP_features %}
+      {% for feature in dependent_features %}
       default_feature_name_map.Set(k{{feature}}PolicyName,
                                    mojom::FeaturePolicyFeature::k{{feature}});
       {% endfor %}
@@ -49,6 +49,25 @@ const FeatureNameMap& GetDefaultFeatureNameMap() {
   return default_feature_name_map;
 }
 
+const FeatureSet& GetAvailableDocumentPolicyFeatures() {
+  DEFINE_STATIC_LOCAL(FeatureSet, features, ());
+  if (features.IsEmpty()) {
+    {% for feature in document_policy_features %}
+    {% if not feature.depends_on or feature.name in origin_trial_dependency_map %}
+    features.insert(mojom::FeaturePolicyFeature::k{{feature.name}});
+    {% endif %}
+    {% endfor %}
+    {% for runtime_feature_name, dependent_features in runtime_to_document_policy_map.items() | sort %}
+    if (RuntimeEnabledFeatures::{{runtime_feature_name}}Enabled()) {
+      {% for feature in dependent_features %}
+      features.insert(mojom::FeaturePolicyFeature::k{{feature}});
+      {% endfor %}
+    }
+    {% endfor %}
+  }
+  return features;
+}
+
 // If any of the origin trial runtime feature is enabled, returns false,
 // i.e. the feature is considered enabled by origin trial.
 bool DisabledByOriginTrial(const String& feature_name,

third_party/blink/renderer/core/BUILD.gn

@@ -861,6 +861,7 @@ blink_python_runner("make_core_generated_feature_policy_helper") {
   inputs = scripts_for_json5_files + [
              "../build/scripts/make_feature_policy_helper.py",
              "./feature_policy/feature_policy_features.json5",
+             "./feature_policy/document_policy_features.json5",
              "../platform/runtime_enabled_features.json5",
              "../build/scripts/templates/feature_policy_helper.cc.tmpl",
            ]
@@ -870,6 +871,8 @@ blink_python_runner("make_core_generated_feature_policy_helper") {
     rebase_path("../platform/runtime_enabled_features.json5", root_build_dir),
     rebase_path("./feature_policy/feature_policy_features.json5",
                 root_build_dir),
+    rebase_path("./feature_policy/document_policy_features.json5",
+                root_build_dir),
     "--output_dir",
     "$rel_blink_core_gen_dir/feature_policy",
   ]

third_party/blink/renderer/core/feature_policy/document_policy_features.json5

+{
+  // All document policy (https://w3c.github.io/webappsec-feature-policy/document-policy.html)
+  // features are defined here.
+  // All Features have to be defined in FeaturePolicyFeature enum as well
+  // (defined in third_party/blink/public/mojom/feature_policy/feature_policy.mojom).
+  // The enum value has to have the same name as the feature name here.
+
+  parameters: {
+    // document_policy_name: "FEATURE_NAME" is used to specify the policy name
+    // which gets parsed from the header or the allow attribute.
+    document_policy_name: {},
+    value_name: {},
+    // valid c++ type strings, e.g. bool, double, float.
+    value_type: {},
+    // valid c++ expression strings, e.g. true/false, 1.0, -1.
+    default_value: {},
+    // "depends_on" specifies relationship to runtime features defined
+    // in "runtime_enabled_features.json5":
+    // depends_on: ["feature1", "feature2", ...]
+    // * If the depends_on features are *only* runtime features, the feature is
+    //   available if any of the runtime features are enabled.
+    // * If the depends_on list includes origin trial features, the feature is
+    //   available if any of the origin trial features are enabled.
+    depends_on: {
+      default: [],
+      valid_type: "list",
+    },
+  },
+
+  data: [
+    {
+      name: "FontDisplay",
+      document_policy_name: "font-display-late-swap",
+      value_name: "",
+      value_type: "bool",
+      default_value: "true",
+      depends_on: ["ExperimentalProductivityFeatures"],
+    },
+    {
+      name: "UnoptimizedLosslessImages",
+      document_policy_name: "unoptimized-lossless-images",
+      value_name: "bpp",
+      value_type: "double",
+      default_value: "PolicyValue::CreateMaxPolicyValue(mojom::PolicyValueType::kDecDouble)",
+      depends_on: ["UnoptimizedImagePolicies"],
+    },
+  ],
+}

third_party/blink/renderer/core/feature_policy/feature_policy_helper.h

@@ -9,11 +9,14 @@
 #include "third_party/blink/public/mojom/feature_policy/feature_policy.mojom-blink-forward.h"
 #include "third_party/blink/public/mojom/feature_policy/feature_policy_feature.mojom-blink-forward.h"
 #include "third_party/blink/renderer/platform/wtf/hash_map.h"
+#include "third_party/blink/renderer/platform/wtf/hash_set.h"
 #include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
 
 namespace blink {
 
 using FeatureNameMap = HashMap<String, mojom::blink::FeaturePolicyFeature>;
+using FeatureSet = HashSet<mojom::blink::FeaturePolicyFeature,
+                           IntHash<mojom::blink::FeaturePolicyFeature>>;
 
 class FeatureContext;
 
@@ -23,6 +26,12 @@ class FeatureContext;
 // policy object.
 const FeatureNameMap& GetDefaultFeatureNameMap();
 
+// This method defines the feature names which will be recognized by the parser
+// for the Document-Policy HTTP header and the <iframe> "policy" attribute, as
+// well as the features which will be recognized by the document or iframe
+// policy object.
+const FeatureSet& GetAvailableDocumentPolicyFeatures();
+
 // Returns true if this feature is currently disabled by an origin trial (it is
 // origin trial controlled, and the origin trial is not enabled).
 bool DisabledByOriginTrial(const String&, FeatureContext*);