Move most of ChromeV8Context to a base ScriptContext

This also moves ModuleSystem, RequestSender,
ObjectBackedNativeHandler, and SafeBuiltins
over to //extensions.

Other renderer code is updated minimally to support
these changes.

BUG=359836
TBR=sky@chromium.org for chrome/test
TBR=jamescook@chromium.org for apps/shell
TBR=maruel@chromium.org for PRESUBMIT.py

Review URL: https://codereview.chromium.org/234413005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@263429 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 220 insertions, 0 deletions

diff --git a/extensions/renderer/module_system.h b/extensions/renderer/module_system.h
new file mode 100644
index 0000000..eec25cc
--- /dev/null
+++ b/extensions/renderer/module_system.h
@@ -0,0 +1,220 @@
+// Copyright 2014 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.
+
+#ifndef EXTENSIONS_RENDERER_MODULE_SYSTEM_H_
+#define EXTENSIONS_RENDERER_MODULE_SYSTEM_H_
+
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/compiler_specific.h"
+#include "base/memory/linked_ptr.h"
+#include "base/memory/scoped_ptr.h"
+#include "extensions/renderer/native_handler.h"
+#include "extensions/renderer/object_backed_native_handler.h"
+#include "v8/include/v8.h"
+
+namespace extensions {
+
+class ScriptContext;
+
+// A module system for JS similar to node.js' require() function.
+// Each module has three variables in the global scope:
+//   - exports, an object returned to dependencies who require() this
+//     module.
+//   - require, a function that takes a module name as an argument and returns
+//     that module's exports object.
+//   - requireNative, a function that takes the name of a registered
+//     NativeHandler and returns an object that contains the functions the
+//     NativeHandler defines.
+//
+// Each module in a ModuleSystem is executed at most once and its exports
+// object cached.
+//
+// Note that a ModuleSystem must be used only in conjunction with a single
+// v8::Context.
+// TODO(koz): Rename this to JavaScriptModuleSystem.
+class ModuleSystem : public ObjectBackedNativeHandler {
+ public:
+  class SourceMap {
+   public:
+    virtual ~SourceMap() {}
+    virtual v8::Handle<v8::Value> GetSource(v8::Isolate* isolate,
+                                            const std::string& name) = 0;
+    virtual bool Contains(const std::string& name) = 0;
+  };
+
+  class ExceptionHandler {
+   public:
+    virtual ~ExceptionHandler() {}
+    virtual void HandleUncaughtException(const v8::TryCatch& try_catch) = 0;
+
+   protected:
+    // Formats |try_catch| as a nice string.
+    std::string CreateExceptionString(const v8::TryCatch& try_catch);
+  };
+
+  // Enables native bindings for the duration of its lifetime.
+  class NativesEnabledScope {
+   public:
+    explicit NativesEnabledScope(ModuleSystem* module_system);
+    ~NativesEnabledScope();
+
+   private:
+    ModuleSystem* module_system_;
+    DISALLOW_COPY_AND_ASSIGN(NativesEnabledScope);
+  };
+
+  // |source_map| is a weak pointer.
+  ModuleSystem(ScriptContext* context, SourceMap* source_map);
+  virtual ~ModuleSystem();
+
+  // Require the specified module. This is the equivalent of calling
+  // require('module_name') from the loaded JS files.
+  v8::Handle<v8::Value> Require(const std::string& module_name);
+  void Require(const v8::FunctionCallbackInfo<v8::Value>& args);
+
+  // Run |code| in the current context with the name |name| used for stack
+  // traces.
+  v8::Handle<v8::Value> RunString(v8::Handle<v8::String> code,
+                                  v8::Handle<v8::String> name);
+
+  // Calls the specified method exported by the specified module. This is
+  // equivalent to calling require('module_name').method_name() from JS.
+  v8::Local<v8::Value> CallModuleMethod(const std::string& module_name,
+                                        const std::string& method_name);
+  v8::Local<v8::Value> CallModuleMethod(
+      const std::string& module_name,
+      const std::string& method_name,
+      std::vector<v8::Handle<v8::Value> >* args);
+  v8::Local<v8::Value> CallModuleMethod(const std::string& module_name,
+                                        const std::string& method_name,
+                                        int argc,
+                                        v8::Handle<v8::Value> argv[]);
+
+  // Register |native_handler| as a potential target for requireNative(), so
+  // calls to requireNative(|name|) from JS will return a new object created by
+  // |native_handler|.
+  void RegisterNativeHandler(const std::string& name,
+                             scoped_ptr<NativeHandler> native_handler);
+
+  // Causes requireNative(|name|) to look for its module in |source_map_|
+  // instead of using a registered native handler. This can be used in unit
+  // tests to mock out native modules.
+  void OverrideNativeHandlerForTest(const std::string& name);
+
+  // Executes |code| in the current context with |name| as the filename.
+  void RunString(const std::string& code, const std::string& name);
+
+  // Make |object|.|field| lazily evaluate to the result of
+  // require(|module_name|)[|module_field|].
+  //
+  // TODO(kalman): All targets for this method are ObjectBackedNativeHandlers,
+  //               move this logic into those classes (in fact, the chrome
+  //               object is the only client, only that needs to implement it).
+  void SetLazyField(v8::Handle<v8::Object> object,
+                    const std::string& field,
+                    const std::string& module_name,
+                    const std::string& module_field);
+
+  void SetLazyField(v8::Handle<v8::Object> object,
+                    const std::string& field,
+                    const std::string& module_name,
+                    const std::string& module_field,
+                    v8::AccessorGetterCallback getter);
+
+  // Make |object|.|field| lazily evaluate to the result of
+  // requireNative(|module_name|)[|module_field|].
+  // TODO(kalman): Same as above.
+  void SetNativeLazyField(v8::Handle<v8::Object> object,
+                          const std::string& field,
+                          const std::string& module_name,
+                          const std::string& module_field);
+
+  // Passes exceptions to |handler| rather than console::Fatal.
+  void SetExceptionHandlerForTest(scoped_ptr<ExceptionHandler> handler) {
+    exception_handler_ = handler.Pass();
+  }
+
+ protected:
+  friend class ScriptContext;
+  virtual void Invalidate() OVERRIDE;
+
+ private:
+  typedef std::map<std::string, linked_ptr<NativeHandler> > NativeHandlerMap;
+
+  // Retrieves the lazily defined field specified by |property|.
+  static void LazyFieldGetter(v8::Local<v8::String> property,
+                              const v8::PropertyCallbackInfo<v8::Value>& info);
+  // Retrieves the lazily defined field specified by |property| on a native
+  // object.
+  static void NativeLazyFieldGetter(
+      v8::Local<v8::String> property,
+      const v8::PropertyCallbackInfo<v8::Value>& info);
+
+  // Called when an exception is thrown but not caught.
+  void HandleException(const v8::TryCatch& try_catch);
+
+  // Ensure that require_ has been evaluated from require.js.
+  void EnsureRequireLoaded();
+
+  void RequireForJs(const v8::FunctionCallbackInfo<v8::Value>& args);
+  v8::Local<v8::Value> RequireForJsInner(v8::Handle<v8::String> module_name);
+
+  typedef v8::Handle<v8::Value>(ModuleSystem::*RequireFunction)(
+      const std::string&);
+  // Base implementation of a LazyFieldGetter which uses |require_fn| to require
+  // modules.
+  static void LazyFieldGetterInner(
+      v8::Local<v8::String> property,
+      const v8::PropertyCallbackInfo<v8::Value>& info,
+      RequireFunction require_function);
+
+  // Return the named source file stored in the source map.
+  // |args[0]| - the name of a source file in source_map_.
+  v8::Handle<v8::Value> GetSource(const std::string& module_name);
+
+  // Return an object that contains the native methods defined by the named
+  // NativeHandler.
+  // |args[0]| - the name of a native handler object.
+  v8::Handle<v8::Value> RequireNativeFromString(const std::string& native_name);
+  void RequireNative(const v8::FunctionCallbackInfo<v8::Value>& args);
+
+  // Wraps |source| in a (function(require, requireNative, exports) {...}).
+  v8::Handle<v8::String> WrapSource(v8::Handle<v8::String> source);
+
+  // NativeHandler implementation which returns the private area of an Object.
+  void Private(const v8::FunctionCallbackInfo<v8::Value>& args);
+
+  // NativeHandler implementation which returns a function wrapper for a
+  // provided function.
+  void CreateFunctionWrapper(const v8::FunctionCallbackInfo<v8::Value>& args);
+
+  ScriptContext* context_;
+
+  // A map from module names to the JS source for that module. GetSource()
+  // performs a lookup on this map.
+  SourceMap* source_map_;
+
+  // A map from native handler names to native handlers.
+  NativeHandlerMap native_handler_map_;
+
+  // When 0, natives are disabled, otherwise indicates how many callers have
+  // pinned natives as enabled.
+  int natives_enabled_;
+
+  // Called when an exception is thrown but not caught in JS. Overridable by
+  // tests.
+  scoped_ptr<ExceptionHandler> exception_handler_;
+
+  std::set<std::string> overridden_native_handlers_;
+
+  DISALLOW_COPY_AND_ASSIGN(ModuleSystem);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_RENDERER_MODULE_SYSTEM_H_