content/renderer/pepper/pepper_try_catch.cc

// 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.

#include "content/renderer/pepper/pepper_try_catch.h"

#include "content/renderer/pepper/pepper_plugin_instance_impl.h"
#include "content/renderer/pepper/v8_var_converter.h"
#include "gin/converter.h"
#include "ppapi/shared_impl/ppapi_globals.h"
#include "ppapi/shared_impl/var_tracker.h"

namespace content {

namespace {

const char kConversionException[] =
    "Error: Failed conversion between PP_Var and V8 value";
const char kInvalidException[] = "Error: An invalid exception was thrown.";

}  // namespace

PepperTryCatch::PepperTryCatch(PepperPluginInstanceImpl* instance,
                               bool convert_objects)
    : instance_(instance),
      convert_objects_(convert_objects) {}

PepperTryCatch::~PepperTryCatch() {}

v8::Handle<v8::Context> PepperTryCatch::GetContext() {
  return instance_->GetContext();
}

v8::Handle<v8::Value> PepperTryCatch::ToV8(PP_Var var) {
  V8VarConverter converter(instance_->pp_instance(), convert_objects_);
  v8::Handle<v8::Value> result;
  bool success = converter.ToV8Value(var, GetContext(), &result);
  if (!success) {
    SetException(kConversionException);
    return v8::Handle<v8::Value>();
  }
  return result;
}

ppapi::ScopedPPVar PepperTryCatch::FromV8(v8::Handle<v8::Value> v8_value) {
  if (v8_value.IsEmpty()) {
    SetException(kConversionException);
    return ppapi::ScopedPPVar();
  }
  ppapi::ScopedPPVar result;
  V8VarConverter converter(instance_->pp_instance(), convert_objects_);
  bool success = converter.FromV8ValueSync(v8_value, GetContext(), &result);
  if (!success) {
    SetException(kConversionException);
    return ppapi::ScopedPPVar();
  }
  return result;
}

PepperTryCatchV8::PepperTryCatchV8(PepperPluginInstanceImpl* instance,
                                   bool convert_objects,
                                   v8::Isolate* isolate)
    : PepperTryCatch(instance, convert_objects),
      exception_(PP_MakeUndefined()) {
  // Typically when using PepperTryCatchV8 we are passed an isolate. We verify
  // that this isolate is the same as the plugin isolate.
  DCHECK(isolate == instance_->GetIsolate());
  // We assume we are already in the plugin context for PepperTryCatchV8.
  DCHECK(GetContext() == isolate->GetCurrentContext());
}

PepperTryCatchV8::~PepperTryCatchV8() {
  ppapi::PpapiGlobals::Get()->GetVarTracker()->ReleaseVar(exception_);
}

bool PepperTryCatchV8::HasException() {
  return exception_.type != PP_VARTYPE_UNDEFINED;
}

bool PepperTryCatchV8::ThrowException() {
  if (!HasException())
    return false;

  std::string message(kInvalidException);
  ppapi::StringVar* message_var = ppapi::StringVar::FromPPVar(exception_);
  if (message_var)
    message = message_var->value();
  instance_->GetIsolate()->ThrowException(v8::Exception::Error(
      gin::StringToV8(instance_->GetIsolate(), message)));

  ppapi::PpapiGlobals::Get()->GetVarTracker()->ReleaseVar(exception_);
  exception_ = PP_MakeUndefined();
  return true;
}

void PepperTryCatchV8::ThrowException(const char* message) {
  SetException(message);
  ThrowException();
}

void PepperTryCatchV8::SetException(const char* message) {
  if (HasException()) {
    NOTREACHED();
    return;
  }
  exception_ = ppapi::StringVar::StringToPPVar(message);
}

PepperTryCatchVar::PepperTryCatchVar(PepperPluginInstanceImpl* instance,
                                     bool convert_objects,
                                     PP_Var* exception)
    : PepperTryCatch(instance, convert_objects),
      handle_scope_(instance_->GetIsolate()),
      exception_(exception),
      exception_is_set_(false) {
  // We switch to the plugin context.
  GetContext()->Enter();
}

PepperTryCatchVar::~PepperTryCatchVar() {
  GetContext()->Exit();
}

bool PepperTryCatchVar::HasException() {
  // Check if a v8 exception was caught.
  if (!exception_is_set_ && try_catch_.HasCaught()) {
    v8::String::Utf8Value utf8(try_catch_.Message()->Get());
    if (exception_) {
      *exception_ = ppapi::StringVar::StringToPPVar(
          std::string(*utf8, utf8.length()));
    }
    exception_is_set_ = true;
  }

  return exception_is_set_;
}

void PepperTryCatchVar::SetException(const char* message) {
  if (exception_is_set_) {
    NOTREACHED();
    return;
  }
  if (exception_)
    *exception_ = ppapi::StringVar::StringToPPVar(message, strlen(message));
  exception_is_set_ = true;
}

}  // namespace content