/* -*- 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 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 "jsfriendapi.h" #include "js/Conversions.h" #include "nsString.h" class nsIScriptContext; class nsIScriptGlobalObject; namespace mozilla { namespace dom { class AutoJSAPI; class Element; } // namespace dom } // namespace mozilla class nsJSUtils { public: static bool GetCallingLocation(JSContext* aContext, nsACString& aFilename, uint32_t* aLineno = nullptr, uint32_t* aColumn = nullptr); static bool GetCallingLocation(JSContext* aContext, nsAString& aFilename, uint32_t* aLineno = nullptr, uint32_t* aColumn = nullptr); static nsIScriptGlobalObject *GetStaticScriptGlobal(JSObject* aObj); static nsIScriptContext *GetStaticScriptContext(JSObject* aObj); /** * 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); static nsresult CompileFunction(mozilla::dom::AutoJSAPI& jsapi, JS::AutoObjectVector& aScopeChain, JS::CompileOptions& aOptions, const nsACString& aName, uint32_t aArgCount, const char** aArgArray, const nsAString& aBody, JSObject** aFunctionObject); struct MOZ_STACK_CLASS EvaluateOptions { bool coerceToString; JS::AutoObjectVector scopeChain; explicit EvaluateOptions(JSContext* cx) : coerceToString(false) , scopeChain(cx) {} EvaluateOptions& setCoerceToString(bool aCoerce) { coerceToString = aCoerce; return *this; } }; // aEvaluationGlobal is the global to evaluate in. The return value // will then be wrapped back into the compartment aCx is in when // this function is called. For all the EvaluateString overloads, // the JSContext must come from an AutoJSAPI that has had // TakeOwnershipOfErrorReporting() called on it. static nsresult EvaluateString(JSContext* aCx, const nsAString& aScript, JS::Handle<JSObject*> aEvaluationGlobal, JS::CompileOptions &aCompileOptions, const EvaluateOptions& aEvaluateOptions, JS::MutableHandle<JS::Value> aRetValue); static nsresult EvaluateString(JSContext* aCx, JS::SourceBufferHolder& aSrcBuf, JS::Handle<JSObject*> aEvaluationGlobal, JS::CompileOptions &aCompileOptions, const EvaluateOptions& aEvaluateOptions, JS::MutableHandle<JS::Value> aRetValue); static nsresult EvaluateString(JSContext* aCx, const nsAString& aScript, JS::Handle<JSObject*> aEvaluationGlobal, JS::CompileOptions &aCompileOptions); static nsresult EvaluateString(JSContext* aCx, JS::SourceBufferHolder& aSrcBuf, JS::Handle<JSObject*> aEvaluationGlobal, JS::CompileOptions &aCompileOptions, void **aOffThreadToken); static nsresult CompileModule(JSContext* aCx, JS::SourceBufferHolder& aSrcBuf, JS::Handle<JSObject*> aEvaluationGlobal, JS::CompileOptions &aCompileOptions, JS::MutableHandle<JSObject*> aModule); static nsresult ModuleDeclarationInstantiation(JSContext* aCx, JS::Handle<JSObject*> aModule); static nsresult ModuleEvaluation(JSContext* aCx, JS::Handle<JSObject*> aModule); // Returns false if an exception got thrown on aCx. Passing a null // aElement is allowed; that wil produce an empty aScopeChain. static bool GetScopeChainForElement(JSContext* aCx, mozilla::dom::Element* aElement, JS::AutoObjectVector& aScopeChain); static void ResetTimeZone(); private: // Implementation for our EvaluateString bits static nsresult EvaluateString(JSContext* aCx, JS::SourceBufferHolder& aSrcBuf, JS::Handle<JSObject*> aEvaluationGlobal, JS::CompileOptions& aCompileOptions, const EvaluateOptions& aEvaluateOptions, JS::MutableHandle<JS::Value> aRetValue, void **aOffThreadToken); }; template<typename T> inline bool AssignJSString(JSContext *cx, T &dest, JSString *s) { size_t len = js::GetStringLength(s); static_assert(js::MaxStringLength < (1 << 28), "Shouldn't overflow here or in SetCapacity"); if (MOZ_UNLIKELY(!dest.SetLength(len, mozilla::fallible))) { JS_ReportOutOfMemory(cx); return false; } return js::CopyStringChars(cx, dest.BeginWriting(), s, len); } inline void AssignJSFlatString(nsAString &dest, JSFlatString *s) { size_t len = js::GetFlatStringLength(s); static_assert(js::MaxStringLength < (1 << 28), "Shouldn't overflow here or in SetCapacity"); dest.SetLength(len); js::CopyFlatStringChars(dest.BeginWriting(), s, len); } class nsAutoJSString : public nsAutoString { public: /** * nsAutoJSString should be default constructed, which leaves it empty * (this->IsEmpty()), and initialized with one of the init() methods below. */ nsAutoJSString() {} bool init(JSContext* aContext, JSString* str) { return AssignJSString(aContext, *this, str); } bool init(JSContext* aContext, const JS::Value &v) { if (v.isString()) { return init(aContext, v.toString()); } // Stringify, making sure not to run script. JS::Rooted<JSString*> str(aContext); if (v.isObject()) { str = JS_NewStringCopyZ(aContext, "[Object]"); } else { JS::Rooted<JS::Value> rootedVal(aContext, v); str = JS::ToString(aContext, rootedVal); } return str && init(aContext, str); } bool init(JSContext* aContext, jsid id) { JS::Rooted<JS::Value> v(aContext); return JS_IdToValue(aContext, id, &v) && init(aContext, v); } bool init(const JS::Value &v); ~nsAutoJSString() {} }; #endif /* nsJSUtils_h__ */