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Diffstat (limited to 'js/public/friend/JSMEnvironment.h')
| -rw-r--r-- | js/public/friend/JSMEnvironment.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/js/public/friend/JSMEnvironment.h b/js/public/friend/JSMEnvironment.h new file mode 100644 index 0000000000..cdbb7ec359 --- /dev/null +++ b/js/public/friend/JSMEnvironment.h @@ -0,0 +1,93 @@ +/* -*- 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/. */ + +/* + * 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_FRIEND_API, 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_FRIEND_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_FRIEND_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. +// +// See also: JS::CloneAndExecuteScript(...) +extern JS_FRIEND_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_FRIEND_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_FRIEND_API bool IsJSMEnvironment(JSObject* obj); + +} // namespace JS + +#endif // js_friend_JSMEnvironment_h |