dom/script/AutoEntryScript.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef DOM_SCRIPT_AUTOENTRYSCRIPT_H_
   8 #define DOM_SCRIPT_AUTOENTRYSCRIPT_H_
   9
  10 #include "MainThreadUtils.h"
  11 #include "js/Debug.h"
  12 #include "js/TypeDecls.h"
  13 #include "jsapi.h"
  14 #include "mozilla/Attributes.h"
  15 #include "mozilla/Maybe.h"
  16 #include "mozilla/ProfilerLabels.h"
  17 #include "mozilla/dom/JSExecutionManager.h"
  18 #include "mozilla/dom/ScriptSettings.h"
  19
  20 class nsIGlobalObject;
  21 class nsIPrincipal;
  22
  23 namespace xpc {
  24 class AutoScriptActivity;
  25 }
  26
  27 namespace mozilla::dom {
  28
  29 /*
  30  * A class that represents a new script entry point.
  31  *
  32  * |aReason| should be a statically-allocated C string naming the reason we're
  33  * invoking JavaScript code: "setTimeout", "event", and so on. The devtools use
  34  * these strings to label JS execution in timeline and profiling displays.
  35  *
  36  */
  37 class MOZ_STACK_CLASS AutoEntryScript : public AutoJSAPI {
  38  public:
  39   // Constructing the AutoEntryScript will ensure that it enters the
  40   // Realm of aGlobalObject's JSObject and exposes that JSObject to active JS.
  41   AutoEntryScript(nsIGlobalObject* aGlobalObject, const char* aReason,
  42                   bool aIsMainThread = NS_IsMainThread());
  43
  44   // aObject can be any object from the relevant global. It must not be a
  45   // cross-compartment wrapper because CCWs are not associated with a single
  46   // global.
  47   //
  48   // Constructing the AutoEntryScript will ensure that it enters the
  49   // Realm of aObject JSObject and exposes aObject's global to active JS.
  50   AutoEntryScript(JSObject* aObject, const char* aReason,
  51                   bool aIsMainThread = NS_IsMainThread());
  52
  53   ~AutoEntryScript();
  54
  55   void SetWebIDLCallerPrincipal(nsIPrincipal* aPrincipal) {
  56     mWebIDLCallerPrincipal = aPrincipal;
  57   }
  58
  59  private:
  60   // It's safe to make this a weak pointer, since it's the subject principal
  61   // when we go on the stack, so can't go away until after we're gone.  In
  62   // particular, this is only used from the CallSetup constructor, and only in
  63   // the aIsJSImplementedWebIDL case.  And in that case, the subject principal
  64   // is the principal of the callee function that is part of the CallArgs just a
  65   // bit up the stack, and which will outlive us.  So we know the principal
  66   // can't go away until then either.
  67   nsIPrincipal* MOZ_NON_OWNING_REF mWebIDLCallerPrincipal;
  68   friend nsIPrincipal* GetWebIDLCallerPrincipal();
  69
  70   Maybe<xpc::AutoScriptActivity> mScriptActivity;
  71   JS::AutoHideScriptedCaller mCallerOverride;
  72   AutoProfilerLabel mAutoProfilerLabel;
  73   AutoRequestJSThreadExecution mJSThreadExecution;
  74 };
  75
  76 }  // namespace mozilla::dom
  77
  78 #endif  // DOM_SCRIPT_AUTOENTRYSCRIPT_H_