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/* -*- 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
/*
* Functionality provided for the JSM component loader in Gecko, that requires
* its own unique manner of global environment and currently requires assistance
* from SpiderMonkey to do so.
*
* Embedders who aren't Gecko can ignore this header.
*/
#ifndef js_friend_JSMEnvironment_h
#define js_friend_JSMEnvironment_h
#include "jstypes.h" // JS_PUBLIC_API
#include "js/GCVector.h" // JS::StackGCVector
#include "js/TypeDecls.h"
// A 'JSMEnvironment' refers to an environment chain constructed for JSM loading
// in a shared global. Internally it is a NonSyntacticVariablesObject with a
// corresponding extensible LexicalEnvironmentObject that is accessible by
// JS_ExtensibleLexicalEnvironment. The |this| value of that lexical environment
// is the NSVO itself.
//
// Normal global environment (ES6): JSM "global" environment:
//
// * - extensible lexical environment
// | (code runs in this environment;
// | `let/const` bindings go here)
// |
// * - JSMEnvironment (=== `this`)
// | (`var` bindings go here)
// |
// * - extensible lexical environment * - extensible lexical environment
// | (code runs in this environment; | (empty)
// | `let/const` bindings go here) |
// | |
// * - actual global (=== `this`) * - shared JSM global
// (var bindings go here; and (Object, Math, etc. live here)
// Object, Math, etc. live here)
namespace JS {
/**
* Allocate a new environment in the current compartment that is compatible with
* JSM shared loading.
*/
extern JS_PUBLIC_API JSObject* NewJSMEnvironment(JSContext* cx);
/**
* Execute the given script (copied into the current compartment if necessary)
* in the given JSMEnvironment. The script must have been compiled for
* hasNonSyntacticScope. The |jsmEnv| must have been previously allocated by
* |NewJSMEnvironment|.
*
* NOTE: The associated extensible lexical environment is reused.
*/
extern JS_PUBLIC_API bool ExecuteInJSMEnvironment(JSContext* cx,
Handle<JSScript*> script,
Handle<JSObject*> jsmEnv);
// Additionally, target objects may be specified as required by the Gecko
// subscript loader. These are wrapped in non-syntactic WithEnvironments and
// temporarily placed on the environment chain.
extern JS_PUBLIC_API bool ExecuteInJSMEnvironment(
JSContext* cx, Handle<JSScript*> script, Handle<JSObject*> jsmEnv,
Handle<StackGCVector<JSObject*>> targetObj);
// Used by native methods to determine the JSMEnvironment of caller if possible
// by looking at stack frames. Returns nullptr if top frame isn't a scripted
// caller in a JSM.
//
// NOTE: This may find NonSyntacticVariablesObject generated by other embedding
// such as a Gecko FrameScript. Caller can check the compartment if needed.
extern JS_PUBLIC_API JSObject* GetJSMEnvironmentOfScriptedCaller(JSContext* cx);
/**
* Determine if obj is a JSMEnvironment
*
* NOTE: This may return true for an NonSyntacticVariablesObject generated by
* other embedding such as a Gecko FrameScript. Caller can check compartment.
*/
extern JS_PUBLIC_API bool IsJSMEnvironment(JSObject* obj);
} // namespace JS
#endif // js_friend_JSMEnvironment_h