gecko-dev/dom/base/DOMException.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_DOMException_h__
#define mozilla_dom_DOMException_h__

// We intentionally shadow non-virtual methods, but gcc gets confused.
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Woverloaded-virtual"
#endif

#include <stdint.h>
#include "jspubtd.h"
#include "js/GCAPI.h"
#include "nsCOMPtr.h"
#include "nsCycleCollectionParticipant.h"
#include "nsID.h"
#include "nsIDOMDOMException.h"
#include "nsWrapperCache.h"
#include "xpcexception.h"
#include "nsString.h"
#include "mozilla/dom/BindingDeclarations.h"

class nsIStackFrame;
class nsString;

nsresult
NS_GetNameAndMessageForDOMNSResult(nsresult aNSResult, nsACString& aName,
                                   nsACString& aMessage,
                                   uint16_t* aCode = nullptr);

namespace mozilla {
class ErrorResult;

namespace dom {

class GlobalObject;

#define MOZILLA_EXCEPTION_IID \
{ 0x55eda557, 0xeba0, 0x4fe3, \
  { 0xae, 0x2e, 0xf3, 0x94, 0x49, 0x23, 0x62, 0xd6 } }

class Exception : public nsIXPCException,
                  public nsWrapperCache
{
public:
  NS_DECLARE_STATIC_IID_ACCESSOR(MOZILLA_EXCEPTION_IID)

  NS_DEFINE_STATIC_CID_ACCESSOR(NS_XPCEXCEPTION_CID)

  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(Exception)
  
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_NSIEXCEPTION
  NS_DECL_NSIXPCEXCEPTION

  // Cruft used by XPConnect for exceptions originating in JS implemented
  // components.
  bool StealJSVal(JS::Value* aVp);
  void StowJSVal(JS::Value& aVp);

  // WebIDL API
  virtual JSObject* WrapObject(JSContext* cx, JS::Handle<JSObject*> aGivenProto)
    override;

  nsISupports* GetParentObject() const { return nullptr; }

  void GetMessageMoz(nsString& retval);

  uint32_t Result() const;

  void GetName(nsString& retval);

  virtual void GetErrorMessage(nsAString& aRetVal)
  {
    // Since GetName and GetMessageMoz are non-virtual and they deal with
    // different member variables in Exception vs. DOMException, have a 
    // virtual method to ensure the right error message creation.
    nsAutoString name;
    nsAutoString message;
    GetName(name);
    GetMessageMoz(message);
    CreateErrorMessage(name, message, aRetVal);
  }

  // The XPCOM GetFilename does the right thing.  It might throw, but we want to
  // return an empty filename in that case anyway, instead of throwing.

  uint32_t LineNumber(JSContext* aCx) const;

  uint32_t ColumnNumber() const;

  already_AddRefed<nsIStackFrame> GetLocation() const;

  already_AddRefed<nsISupports> GetData() const;

  void GetStack(JSContext* aCx, nsAString& aStack, ErrorResult& aRv) const;

  void Stringify(JSContext* aCx, nsString& retval);

  // XPCOM factory ctor.
  Exception();

  Exception(const nsACString& aMessage,
            nsresult aResult,
            const nsACString& aName,
            nsIStackFrame *aLocation,
            nsISupports *aData);

protected:
  virtual ~Exception();

  void CreateErrorMessage(const nsAString& aName, const nsAString& aMessage,
                          nsAString& aRetVal)
  {
    // Create similar error message as what ErrorReport::init does in jsexn.cpp.
    if (!aName.IsEmpty() && !aMessage.IsEmpty()) {
      aRetVal.Assign(aName);
      aRetVal.AppendLiteral(": ");
      aRetVal.Append(aMessage);
    } else if (!aName.IsEmpty()) {
      aRetVal.Assign(aName);
    } else if (!aMessage.IsEmpty()) {
      aRetVal.Assign(aMessage);
    } else {
      aRetVal.Truncate();
    }
  }

  nsCString       mMessage;
  nsresult        mResult;
  nsCString       mName;
  nsCOMPtr<nsIStackFrame> mLocation;
  nsCOMPtr<nsISupports> mData;
  bool            mInitialized;

  bool mHoldingJSVal;
  JS::Heap<JS::Value> mThrownJSVal;

private:
  static bool sEverMadeOneFromFactory;
};

NS_DEFINE_STATIC_IID_ACCESSOR(Exception, MOZILLA_EXCEPTION_IID)

class DOMException : public Exception,
                     public nsIDOMDOMException
{
public:
  DOMException(nsresult aRv, const nsACString& aMessage,
               const nsACString& aName, uint16_t aCode);

  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_NSIDOMDOMEXCEPTION

  // nsIException overrides
  NS_IMETHOD ToString(JSContext* aCx, nsACString& aReturn) override;

  // nsWrapperCache overrides
  virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
    override;

  static already_AddRefed<DOMException>
  Constructor(GlobalObject& /* unused */,
              const nsAString& aMessage,
              const Optional<nsAString>& aName,
              ErrorResult& aError);

  uint16_t Code() const {
    return mCode;
  }

  // Intentionally shadow the nsXPCException version.
  void GetMessageMoz(nsString& retval);
  void GetName(nsString& retval);

  virtual void GetErrorMessage(nsAString& aRetVal) override
  {
    // See the comment in Exception::GetErrorMessage.
    nsAutoString name;
    nsAutoString message;
    GetName(name);
    GetMessageMoz(message);
    CreateErrorMessage(name, message, aRetVal);
  }

  static already_AddRefed<DOMException>
  Create(nsresult aRv);

  static already_AddRefed<DOMException>
  Create(nsresult aRv, const nsACString& aMessage);

protected:

  virtual ~DOMException() {}

  nsCString mName;
  nsCString mMessage;

  uint16_t mCode;
};

} // namespace dom
} // namespace mozilla

#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif

#endif