The Tor Browser: dom/base/nsJSUtils.cpp@b8a032363ba2 (annotated)

dom/base/nsJSUtils.cpp@b8a032363ba2 (annotated)

dom/base/nsJSUtils.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=2 sw=2 et tw=78: */
 /* 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/. */
 /**
  * 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 "nsJSUtils.h"
 #include "jsapi.h"
 #include "js/OldDebugAPI.h"
 #include "jsfriendapi.h"
 #include "nsIScriptContext.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIXPConnect.h"
 #include "nsCOMPtr.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsPIDOMWindow.h"
 #include "GeckoProfiler.h"
 #include "nsDOMJSUtils.h" // for GetScriptContextFromJSContext
 #include "nsJSPrincipals.h"
 #include "xpcpublic.h"
 #include "nsContentUtils.h"
 #include "nsGlobalWindow.h"
 bool
 nsJSUtils::GetCallingLocation(JSContext* aContext, const char* *aFilename,
                               uint32_t* aLineno)
 {
   JS::AutoFilename filename;
   unsigned lineno = 0;
   if (!JS::DescribeScriptedCaller(aContext, &filename, &lineno)) {
     return false;
   }
   *aFilename = filename.get();
   *aLineno = lineno;
   return true;
 }
 nsIScriptGlobalObject *
 nsJSUtils::GetStaticScriptGlobal(JSObject* aObj)
 {
   if (!aObj)
     return nullptr;
   return xpc::WindowGlobalOrNull(aObj);
 }
 nsIScriptContext *
 nsJSUtils::GetStaticScriptContext(JSObject* aObj)
 {
   nsIScriptGlobalObject *nativeGlobal = GetStaticScriptGlobal(aObj);
   if (!nativeGlobal)
     return nullptr;
   return nativeGlobal->GetScriptContext();
 }
 nsIScriptGlobalObject *
 nsJSUtils::GetDynamicScriptGlobal(JSContext* aContext)
 {
   nsIScriptContext *scriptCX = GetDynamicScriptContext(aContext);
   if (!scriptCX)
     return nullptr;
   return scriptCX->GetGlobalObject();
 }
 nsIScriptContext *
 nsJSUtils::GetDynamicScriptContext(JSContext *aContext)
 {
   return GetScriptContextFromJSContext(aContext);
 }
 uint64_t
 nsJSUtils::GetCurrentlyRunningCodeInnerWindowID(JSContext *aContext)
 {
   if (!aContext)
     return 0;
   uint64_t innerWindowID = 0;
   JSObject *jsGlobal = JS::CurrentGlobalOrNull(aContext);
   if (jsGlobal) {
     nsIScriptGlobalObject *scriptGlobal = GetStaticScriptGlobal(jsGlobal);
     if (scriptGlobal) {
       nsCOMPtr<nsPIDOMWindow> win = do_QueryInterface(scriptGlobal);
       if (win)
         innerWindowID = win->WindowID();
     }
   }
   return innerWindowID;
 }
 void
 nsJSUtils::ReportPendingException(JSContext *aContext)
 {
   if (JS_IsExceptionPending(aContext)) {
     bool saved = JS_SaveFrameChain(aContext);
     {
       // JS_SaveFrameChain set the compartment of aContext to null, so we need
       // to enter a compartment.  The question is, which one? We don't want to
       // enter the original compartment of aContext (or the compartment of the
       // current exception on aContext, for that matter) because when we
       // JS_ReportPendingException the JS engine can try to duck-type the
       // exception and produce a JSErrorReport.  It will then pass that
       // JSErrorReport to the error reporter on aContext, which might expose
       // information from it to script via onerror handlers.  So it's very
       // important that the duck typing happen in the same compartment as the
       // onerror handler.  In practice, that's the compartment of the window (or
       // otherwise default global) of aContext, so use that here.
       nsIScriptContext* scx = GetScriptContextFromJSContext(aContext);
       JS::Rooted<JSObject*> scope(aContext);
       scope = scx ? scx->GetWindowProxy()
                   : js::DefaultObjectForContextOrNull(aContext);
       if (!scope) {
         // The SafeJSContext has no default object associated with it.
         MOZ_ASSERT(NS_IsMainThread());
         MOZ_ASSERT(aContext == nsContentUtils::GetSafeJSContext());
         scope = xpc::GetSafeJSContextGlobal();
       }
       JSAutoCompartment ac(aContext, scope);
       JS_ReportPendingException(aContext);
     }
     if (saved) {
       JS_RestoreFrameChain(aContext);
     }
   }
 }
 nsresult
 nsJSUtils::CompileFunction(JSContext* aCx,
                            JS::Handle<JSObject*> aTarget,
                            JS::CompileOptions& aOptions,
                            const nsACString& aName,
                            uint32_t aArgCount,
                            const char** aArgArray,
                            const nsAString& aBody,
                            JSObject** aFunctionObject)
 {
   MOZ_ASSERT(js::GetEnterCompartmentDepth(aCx) > 0);
   MOZ_ASSERT_IF(aTarget, js::IsObjectInContextCompartment(aTarget, aCx));
   MOZ_ASSERT_IF(aOptions.versionSet, aOptions.version != JSVERSION_UNKNOWN);
   mozilla::DebugOnly<nsIScriptContext*> ctx = GetScriptContextFromJSContext(aCx);
   MOZ_ASSERT_IF(ctx, ctx->IsContextInitialized());
   // Do the junk Gecko is supposed to do before calling into JSAPI.
   if (aTarget) {
     JS::ExposeObjectToActiveJS(aTarget);
   }
   // Compile.
   JSFunction* fun = JS::CompileFunction(aCx, aTarget, aOptions,
                                         PromiseFlatCString(aName).get(),
                                         aArgCount, aArgArray,
                                         PromiseFlatString(aBody).get(),
                                         aBody.Length());
   if (!fun) {
     ReportPendingException(aCx);
     return NS_ERROR_FAILURE;
   }
   *aFunctionObject = JS_GetFunctionObject(fun);
   return NS_OK;
 }
 nsresult
 nsJSUtils::EvaluateString(JSContext* aCx,
                           const nsAString& aScript,
                           JS::Handle<JSObject*> aScopeObject,
                           JS::CompileOptions& aCompileOptions,
                           const EvaluateOptions& aEvaluateOptions,
                           JS::MutableHandle<JS::Value> aRetValue,
                           void **aOffThreadToken)
 {
   const nsPromiseFlatString& flatScript = PromiseFlatString(aScript);
   JS::SourceBufferHolder srcBuf(flatScript.get(), aScript.Length(),
                                 JS::SourceBufferHolder::NoOwnership);
   return EvaluateString(aCx, srcBuf, aScopeObject, aCompileOptions,
                         aEvaluateOptions, aRetValue, aOffThreadToken);
 }
 nsresult
 nsJSUtils::EvaluateString(JSContext* aCx,
                           JS::SourceBufferHolder& aSrcBuf,
                           JS::Handle<JSObject*> aScopeObject,
                           JS::CompileOptions& aCompileOptions,
                           const EvaluateOptions& aEvaluateOptions,
                           JS::MutableHandle<JS::Value> aRetValue,
                           void **aOffThreadToken)
 {
   PROFILER_LABEL("JS", "EvaluateString");
   MOZ_ASSERT_IF(aCompileOptions.versionSet,
                 aCompileOptions.version != JSVERSION_UNKNOWN);
   MOZ_ASSERT_IF(aEvaluateOptions.coerceToString, aEvaluateOptions.needResult);
   MOZ_ASSERT_IF(!aEvaluateOptions.reportUncaught, aEvaluateOptions.needResult);
   MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
   MOZ_ASSERT(aSrcBuf.get());
   // Unfortunately, the JS engine actually compiles scripts with a return value
   // in a different, less efficient way.  Furthermore, it can't JIT them in many
   // cases.  So we need to be explicitly told whether the caller cares about the
   // return value.  Callers can do this by calling the other overload of
   // EvaluateString() which calls this function with aEvaluateOptions.needResult
   // set to false.
   aRetValue.setUndefined();
   JS::ExposeObjectToActiveJS(aScopeObject);
   nsAutoMicroTask mt;
   nsresult rv = NS_OK;
   bool ok = false;
   nsIScriptSecurityManager* ssm = nsContentUtils::GetSecurityManager();
   NS_ENSURE_TRUE(ssm->ScriptAllowed(js::GetGlobalForObjectCrossCompartment(aScopeObject)), NS_OK);
   mozilla::Maybe<AutoDontReportUncaught> dontReport;
   if (!aEvaluateOptions.reportUncaught) {
     // We need to prevent AutoLastFrameCheck from reporting and clearing
     // any pending exceptions.
     dontReport.construct(aCx);
   }
   // Scope the JSAutoCompartment so that we can later wrap the return value
   // into the caller's cx.
   {
     JSAutoCompartment ac(aCx, aScopeObject);
     JS::Rooted<JSObject*> rootedScope(aCx, aScopeObject);
     if (aOffThreadToken) {
       JS::Rooted<JSScript*>
         script(aCx, JS::FinishOffThreadScript(aCx, JS_GetRuntime(aCx), *aOffThreadToken));
       *aOffThreadToken = nullptr; // Mark the token as having been finished.
       if (script) {
         if (aEvaluateOptions.needResult) {
           ok = JS_ExecuteScript(aCx, rootedScope, script, aRetValue);
         } else {
           ok = JS_ExecuteScript(aCx, rootedScope, script);
         }
       } else {
         ok = false;
       }
     } else {
       if (aEvaluateOptions.needResult) {
         ok = JS::Evaluate(aCx, rootedScope, aCompileOptions,
                           aSrcBuf, aRetValue);
       } else {
         ok = JS::Evaluate(aCx, rootedScope, aCompileOptions,
                           aSrcBuf);
       }
     }
     if (ok && aEvaluateOptions.coerceToString && !aRetValue.isUndefined()) {
       JS::Rooted<JS::Value> value(aCx, aRetValue);
       JSString* str = JS::ToString(aCx, value);
       ok = !!str;
       aRetValue.set(ok ? JS::StringValue(str) : JS::UndefinedValue());
     }
   }
   if (!ok) {
     if (aEvaluateOptions.reportUncaught) {
       ReportPendingException(aCx);
       if (aEvaluateOptions.needResult) {
         aRetValue.setUndefined();
       }
     } else {
       rv = JS_IsExceptionPending(aCx) ? NS_ERROR_FAILURE
                                       : NS_ERROR_OUT_OF_MEMORY;
       JS::Rooted<JS::Value> exn(aCx);
       JS_GetPendingException(aCx, &exn);
       if (aEvaluateOptions.needResult) {
         aRetValue.set(exn);
       }
       JS_ClearPendingException(aCx);
     }
   }
   // Wrap the return value into whatever compartment aCx was in.
   if (aEvaluateOptions.needResult) {
     JS::Rooted<JS::Value> v(aCx, aRetValue);
     if (!JS_WrapValue(aCx, &v)) {
       return NS_ERROR_OUT_OF_MEMORY;
     }
     aRetValue.set(v);
   }
   return rv;
 }
 nsresult
 nsJSUtils::EvaluateString(JSContext* aCx,
                           const nsAString& aScript,
                           JS::Handle<JSObject*> aScopeObject,
                           JS::CompileOptions& aCompileOptions,
                           void **aOffThreadToken)
 {
   EvaluateOptions options;
   options.setNeedResult(false);
   JS::RootedValue unused(aCx);
   return EvaluateString(aCx, aScript, aScopeObject, aCompileOptions,
                         options, &unused, aOffThreadToken);
 }
 nsresult
 nsJSUtils::EvaluateString(JSContext* aCx,
                           JS::SourceBufferHolder& aSrcBuf,
                           JS::Handle<JSObject*> aScopeObject,
                           JS::CompileOptions& aCompileOptions,
                           void **aOffThreadToken)
 {
   EvaluateOptions options;
   options.setNeedResult(false);
   JS::RootedValue unused(aCx);
   return EvaluateString(aCx, aSrcBuf, aScopeObject, aCompileOptions,
                         options, &unused, aOffThreadToken);
 }
 //
 // nsDOMJSUtils.h
 //
 JSObject* GetDefaultScopeFromJSContext(JSContext *cx)
 {
   // DOM JSContexts don't store their default compartment object on
   // the cx, so in those cases we need to fetch it via the scx
   // instead.
   nsIScriptContext *scx = GetScriptContextFromJSContext(cx);
   if (scx) {
     return scx->GetWindowProxy();
   }
   return js::DefaultObjectForContextOrNull(cx);
 }

The Tor Browser / annotate

dom/base/nsJSUtils.cpp@b8a032363ba2 (annotated)

dom/base/nsJSUtils.cpp