dom/base/nsJSUtils.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=2 sw=2 et tw=78: */
   3 /* ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
  10  *
  11  * Software distributed under the License is distributed on an "AS IS" basis,
  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is mozilla.org code.
  17  *
  18  * The Initial Developer of the Original Code is
  19  * Netscape Communications Corporation.
  20  * Portions created by the Initial Developer are Copyright (C) 1998
  21  * the Initial Developer. All Rights Reserved.
  22  *
  23  * Contributor(s):
  24  *   Vidur Apparao <vidur@netscape.com>
  25  *   L. David Baron <dbaron@mozillafoundation.org>
  26  *
  27  * Alternatively, the contents of this file may be used under the terms of
  28  * either of the GNU General Public License Version 2 or later (the "GPL"),
  29  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  30  * in which case the provisions of the GPL or the LGPL are applicable instead
  31  * of those above. If you wish to allow use of your version of this file only
  32  * under the terms of either the GPL or the LGPL, and not to allow others to
  33  * use your version of this file under the terms of the MPL, indicate your
  34  * decision by deleting the provisions above and replace them with the notice
  35  * and other provisions required by the GPL or the LGPL. If you do not delete
  36  * the provisions above, a recipient may use your version of this file under
  37  * the terms of any one of the MPL, the GPL or the LGPL.
  38  *
  39  * ***** END LICENSE BLOCK ***** */
  40
  41 /**
  42  * This is not a generated file. It contains common utility functions
  43  * invoked from the JavaScript code generated from IDL interfaces.
  44  * The goal of the utility functions is to cut down on the size of
  45  * the generated code itself.
  46  */
  47
  48 #include "nsJSUtils.h"
  49 #include "jsapi.h"
  50 #include "jsdbgapi.h"
  51 #include "prprf.h"
  52 #include "nsIScriptContext.h"
  53 #include "nsIScriptObjectOwner.h"
  54 #include "nsIScriptGlobalObject.h"
  55 #include "nsIServiceManager.h"
  56 #include "nsIXPConnect.h"
  57 #include "nsCOMPtr.h"
  58 #include "nsContentUtils.h"
  59 #include "nsIScriptSecurityManager.h"
  60
  61 #include "nsDOMJSUtils.h" // for GetScriptContextFromJSContext
  62
  63 JSBool
  64 nsJSUtils::GetCallingLocation(JSContext* aContext, const char* *aFilename,
  65                               PRUint32* aLineno, nsIPrincipal* aPrincipal)
  66 {
  67   // Get the current filename and line number
  68   JSStackFrame* frame = nsnull;
  69   JSScript* script = nsnull;
  70   do {
  71     frame = ::JS_FrameIterator(aContext, &frame);
  72
  73     if (frame) {
  74       script = ::JS_GetFrameScript(aContext, frame);
  75     }
  76   } while (frame && !script);
  77
  78   if (script) {
  79     // If aPrincipals is non-null then our caller is asking us to ensure
  80     // that the filename we return does not have elevated privileges.
  81     if (aPrincipal) {
  82       uint32 flags = JS_GetScriptFilenameFlags(script);
  83
  84       // Use the principal for the filename if it shouldn't be receiving
  85       // implicit XPCNativeWrappers.
  86       PRBool system;
  87       if (flags & JSFILENAME_PROTECTED) {
  88         nsIScriptSecurityManager *ssm = nsContentUtils::GetSecurityManager();
  89
  90         if (NS_FAILED(ssm->IsSystemPrincipal(aPrincipal, &system)) || !system) {
  91           JSPrincipals* jsprins;
  92           aPrincipal->GetJSPrincipals(aContext, &jsprins);
  93
  94           *aFilename = jsprins->codebase;
  95           *aLineno = 0;
  96           JSPRINCIPALS_DROP(aContext, jsprins);
  97           return JS_TRUE;
  98         }
  99       }
 100     }
 101
 102     const char* filename = ::JS_GetScriptFilename(aContext, script);
 103
 104     if (filename) {
 105       PRUint32 lineno = 0;
 106       jsbytecode* bytecode = ::JS_GetFramePC(aContext, frame);
 107
 108       if (bytecode) {
 109         lineno = ::JS_PCToLineNumber(aContext, script, bytecode);
 110       }
 111
 112       *aFilename = filename;
 113       *aLineno = lineno;
 114       return JS_TRUE;
 115     }
 116   }
 117
 118   return JS_FALSE;
 119 }
 120
 121 nsIScriptGlobalObject *
 122 nsJSUtils::GetStaticScriptGlobal(JSContext* aContext, JSObject* aObj)
 123 {
 124   nsISupports* supports;
 125   JSClass* clazz;
 126   JSObject* parent;
 127   JSObject* glob = aObj; // starting point for search
 128
 129   if (!glob)
 130     return nsnull;
 131
 132   while ((parent = ::JS_GetParent(aContext, glob)))
 133     glob = parent;
 134
 135   clazz = JS_GET_CLASS(aContext, glob);
 136
 137   if (!clazz ||
 138       !(clazz->flags & JSCLASS_HAS_PRIVATE) ||
 139       !(clazz->flags & JSCLASS_PRIVATE_IS_NSISUPPORTS) ||
 140       !(supports = (nsISupports*)::JS_GetPrivate(aContext, glob))) {
 141     return nsnull;
 142   }
 143
 144   nsCOMPtr<nsIXPConnectWrappedNative> wrapper(do_QueryInterface(supports));
 145   NS_ENSURE_TRUE(wrapper, nsnull);
 146
 147   nsCOMPtr<nsIScriptGlobalObject> sgo(do_QueryWrappedNative(wrapper));
 148
 149   // We're returning a pointer to something that's about to be
 150   // released, but that's ok here.
 151   return sgo;
 152 }
 153
 154 nsIScriptContext *
 155 nsJSUtils::GetStaticScriptContext(JSContext* aContext, JSObject* aObj)
 156 {
 157   nsIScriptGlobalObject *nativeGlobal = GetStaticScriptGlobal(aContext, aObj);
 158   if (!nativeGlobal)
 159     return nsnull;
 160
 161   return nativeGlobal->GetScriptContext(nsIProgrammingLanguage::JAVASCRIPT);
 162 }
 163
 164 nsIScriptGlobalObject *
 165 nsJSUtils::GetDynamicScriptGlobal(JSContext* aContext)
 166 {
 167   nsIScriptContext *scriptCX = GetDynamicScriptContext(aContext);
 168   if (!scriptCX)
 169     return nsnull;
 170   return scriptCX->GetGlobalObject();
 171 }
 172
 173 nsIScriptContext *
 174 nsJSUtils::GetDynamicScriptContext(JSContext *aContext)
 175 {
 176   return GetScriptContextFromJSContext(aContext);
 177 }