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 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* 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 nsJSUtils_h__

 #define nsJSUtils_h__

 /**

  * This is not a generated file. It contains common utility functions 

  * invoked from the JavaScript code generated from IDL interfaces.

  * The goal of the utility functions is to cut down on the size of

  * the generated code itself.

  */

 #include "mozilla/Assertions.h"

 #include "jsapi.h"

 #include "nsString.h"

 class nsIScriptContext;

 class nsIScriptGlobalObject;

 class nsJSUtils

 {

 public:

   static bool GetCallingLocation(JSContext* aContext, const char* *aFilename,

                                  uint32_t* aLineno);

   static nsIScriptGlobalObject *GetStaticScriptGlobal(JSObject* aObj);

   static nsIScriptContext *GetStaticScriptContext(JSObject* aObj);

   static nsIScriptGlobalObject *GetDynamicScriptGlobal(JSContext *aContext);

   static nsIScriptContext *GetDynamicScriptContext(JSContext *aContext);

   /**

    * Retrieve the inner window ID based on the given JSContext.

    *

    * @param JSContext aContext

    *        The JSContext from which you want to find the inner window ID.

    *

    * @returns uint64_t the inner window ID.

    */

   static uint64_t GetCurrentlyRunningCodeInnerWindowID(JSContext *aContext);

   /**

    * Report a pending exception on aContext, if any.  Note that this

    * can be called when the context has a JS stack.  If that's the

    * case, the stack will be set aside before reporting the exception.

    */

   static void ReportPendingException(JSContext *aContext);

   static nsresult CompileFunction(JSContext* aCx,

                                   JS::Handle<JSObject*> aTarget,

                                   JS::CompileOptions& aOptions,

                                   const nsACString& aName,

                                   uint32_t aArgCount,

                                   const char** aArgArray,

                                   const nsAString& aBody,

                                   JSObject** aFunctionObject);

   struct EvaluateOptions {

     bool coerceToString;

     bool reportUncaught;

     bool needResult;

     explicit EvaluateOptions() : coerceToString(false)

                                , reportUncaught(true)

                                , needResult(true)

     {}

     EvaluateOptions& setCoerceToString(bool aCoerce) {

       coerceToString = aCoerce;

       return *this;

     }

     EvaluateOptions& setReportUncaught(bool aReport) {

       reportUncaught = aReport;

       return *this;

     }

     EvaluateOptions& setNeedResult(bool aNeedResult) {

       needResult = aNeedResult;

       return *this;

     }

   };

   static nsresult EvaluateString(JSContext* aCx,

                                  const nsAString& aScript,

                                  JS::Handle<JSObject*> aScopeObject,

                                  JS::CompileOptions &aCompileOptions,

                                  const EvaluateOptions& aEvaluateOptions,

                                  JS::MutableHandle<JS::Value> aRetValue,

                                  void **aOffThreadToken = nullptr);

   static nsresult EvaluateString(JSContext* aCx,

                                  JS::SourceBufferHolder& aSrcBuf,

                                  JS::Handle<JSObject*> aScopeObject,

                                  JS::CompileOptions &aCompileOptions,

                                  const EvaluateOptions& aEvaluateOptions,

                                  JS::MutableHandle<JS::Value> aRetValue,

                                  void **aOffThreadToken = nullptr);

   static nsresult EvaluateString(JSContext* aCx,

                                  const nsAString& aScript,

                                  JS::Handle<JSObject*> aScopeObject,

                                  JS::CompileOptions &aCompileOptions,

                                  void **aOffThreadToken = nullptr);

   static nsresult EvaluateString(JSContext* aCx,

                                  JS::SourceBufferHolder& aSrcBuf,

                                  JS::Handle<JSObject*> aScopeObject,

                                  JS::CompileOptions &aCompileOptions,

                                  void **aOffThreadToken = nullptr);

 };

 class MOZ_STACK_CLASS AutoDontReportUncaught {

   JSContext* mContext;

   bool mWasSet;

 public:

   AutoDontReportUncaught(JSContext* aContext) : mContext(aContext) {

     MOZ_ASSERT(aContext);

     mWasSet = JS::ContextOptionsRef(mContext).dontReportUncaught();

     if (!mWasSet) {

       JS::ContextOptionsRef(mContext).setDontReportUncaught(true);

     }

   }

   ~AutoDontReportUncaught() {

     if (!mWasSet) {

       JS::ContextOptionsRef(mContext).setDontReportUncaught(false);

     }

   }

 };

 class nsDependentJSString : public nsDependentString

 {

 public:

   /**

    * In the case of string ids, getting the string's chars is infallible, so

    * the dependent string can be constructed directly.

    */

   explicit nsDependentJSString(JS::Handle<jsid> id)

     : nsDependentString(JS_GetInternedStringChars(JSID_TO_STRING(id)),

                         JS_GetStringLength(JSID_TO_STRING(id)))

   {

   }

   /**

    * Ditto for flat strings.

    */

   explicit nsDependentJSString(JSFlatString* fstr)

     : nsDependentString(JS_GetFlatStringChars(fstr),

                         JS_GetStringLength(JS_FORGET_STRING_FLATNESS(fstr)))

   {

   }

   /**

    * For all other strings, the nsDependentJSString object should be default

    * constructed, which leaves it empty (this->IsEmpty()), and initialized with

    * one of the init() methods below.

    */

   nsDependentJSString()

   {

   }

   bool init(JSContext* aContext, JSString* str)

   {

       size_t length;

       const jschar* chars = JS_GetStringCharsZAndLength(aContext, str, &length);

       if (!chars)

           return false;

       NS_ASSERTION(IsEmpty(), "init() on initialized string");

       nsDependentString* base = this;

       new(base) nsDependentString(chars, length);

       return true;

   }

   bool init(JSContext* aContext, const JS::Value &v)

   {

       return init(aContext, JSVAL_TO_STRING(v));

   }

   void init(JSFlatString* fstr)

   {

       MOZ_ASSERT(IsEmpty(), "init() on initialized string");

       new(this) nsDependentJSString(fstr);

   }

   ~nsDependentJSString()

   {

   }

 };

 #endif /* nsJSUtils_h__ */