Add code generation for ConditionalFeatures bindings code

third_party/WebKit/Source/bindings/templates/ConditionalFeaturesForModules.cpp.tmpl

Index: third_party/WebKit/Source/bindings/templates/ConditionalFeaturesForModules.cpp.tmpl
diff --git a/third_party/WebKit/Source/bindings/templates/ConditionalFeaturesForModules.cpp.tmpl b/third_party/WebKit/Source/bindings/templates/ConditionalFeaturesForModules.cpp.tmpl
new file mode 100644
index 0000000000000000000000000000000000000000..50a495191d7160f7b1c3a6f396da6873426c40e3
--- /dev/null
+++ b/third_party/WebKit/Source/bindings/templates/ConditionalFeaturesForModules.cpp.tmpl
@@ -0,0 +1,92 @@
+// Copyright 2017 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.

[chasej, 2017/07/11 20:12:32]

Ditto about copyright include.

[iclelland, 2017/07/12 17:23:20]

Done.

+
+#include "bindings/modules/v8/ConditionalFeaturesForModules.h"
+
+#include "bindings/core/v8/ConditionalFeaturesForCore.h"
+{% for include in includes %}
+#include "{{ include }}"
+{% endfor %}
+
+namespace blink {
+
+namespace {
+InstallConditionalFeaturesFunction
+    g_original_install_conditional_features_function = nullptr;
+InstallPendingConditionalFeatureFunction
+    g_original_install_pending_conditional_feature_function = nullptr;
+}
+
+void InstallConditionalFeaturesForModules(

[chasej, 2017/07/11 20:12:32]

This method seems very similar to the Core version, other than the name and some
specifics for ContextEnabled. Maybe the body should be extracted into a
macro/helper to avoid duplication?

This applies to the other methods and definitions in the file as well.

[iclelland, 2017/07/12 17:23:20]

I've made them identical now, except that the Core version has to have some
special case code for handling the ContextEnabledFeatures, until I refactor that
to make it just another type of autogenerated binding.

I've added a todo to actually extract the method bodies into a template once
that is taken care of.

[chasej, 2017/07/12 19:53:41]

Is that newly-added todo in this CL? I'm not seeing it (although I easily could
have missed it). I see the todo about unifying ContextFeatureSettings in
ConditionalFeaturesForCore.cpp.tmpl.

I'm assuming that handling ContextFeatureSettings, and de-duplicating method
bodies will be later CLs. So, I just want to clarify where the todo will be.

Looking at these templates more, maybe there could be just one template, and
plug in "Core" or "Modules" as necessary? The only material difference could be
that Register..ForModules()_calls Register...ForCore() (and the resulting
includes). I'm working on another CL that should make the
InstallConditionalFeaturesOnWindow() method obsolete.

[iclelland, 2017/07/13 15:32:59]

Oops -- missed it, thanks for catching.
 
That would be great, too :) At that point, I think that we should look at having
either a single template, or two very lightweight templates that rely heavily on
template inheritance to insert most of the actual code from blocks defined in a
common parent.

+    const WrapperTypeInfo* wrapper_type_info,
+    const ScriptState* script_state,
+    v8::Local<v8::Object> prototype_object,
+    v8::Local<v8::Function> interface_object) {
+  (*g_original_install_conditional_features_function)(
+      wrapper_type_info, script_state, prototype_object, interface_object);
+
+  {% if installers_by_interface %}
+  ExecutionContext* execution_context = ExecutionContext::From(script_state);
+  if (!execution_context)
+    return;
+  v8::Isolate* isolate = script_state->GetIsolate();
+  const DOMWrapperWorld& world = script_state->World();
+  {% for interface in installers_by_interface %}
+  if (wrapper_type_info == &{{ interface.class }}::wrapperTypeInfo) {
+    {% if interface.is_global %}
+    v8::Local<v8::Object> instance_object =
+        script_state->GetContext()->Global();
+    {% endif %}
+    {% for installer in interface.installers %}
+    if ({{ installer.condition }}(execution_context)) {
+      {{ installer.class_or_partial }}::{{ installer.install_method }}(
+          isolate, world, {% if interface.is_global %}instance_object{% else %}v8::Local<v8::Object>(){% endif %}, prototype_object,
+          interface_object);
+    }
+    {% endfor %}
+  }
+  {% endfor %}
+  {% endif %}
+}
+
+void InstallPendingConditionalFeatureForModules(
+    const String& feature,
+    const ScriptState* script_state) {
+  (*g_original_install_pending_conditional_feature_function)(feature,
+                                                             script_state);
+
+  {% if installers_by_feature %}
+  v8::Local<v8::Object> prototype_object;
+  v8::Local<v8::Function> interface_object;
+  v8::Isolate* isolate = script_state->GetIsolate();
+  const DOMWrapperWorld& world = script_state->World();
+  V8PerContextData* context_data = script_state->PerContextData();
+  {% for feature in installers_by_feature %}
+  if (feature == "{{ feature.name }}") {
+    {% for installer in feature.installers %}
+    if (context_data->GetExistingConstructorAndPrototypeForType(
+            &{{ installer.class }}::wrapperTypeInfo, &prototype_object,
+            &interface_object)) {
+      {{ installer.class_or_partial }}::{{ installer.install_method }}(
+          isolate, world, v8::Local<v8::Object>(), prototype_object,
+          interface_object);
+    }
+    {% endfor %}
+    return;
+  }
+  {% endfor %}
+  {% endif %}
+}
+
+void RegisterInstallConditionalFeaturesForModules() {
+  RegisterInstallConditionalFeaturesForCore();
+  g_original_install_conditional_features_function =
+      SetInstallConditionalFeaturesFunction(
+          &InstallConditionalFeaturesForModules);
+  g_original_install_pending_conditional_feature_function =
+      SetInstallPendingConditionalFeatureFunction(
+          &InstallPendingConditionalFeatureForModules);
+}
+
+}  // namespace blink