LCOV - code coverage report
Current view: directory - js/xpconnect/src - XPCThrower.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 127 98 77.2 %
Date: 2012-06-02 Functions: 9 9 100.0 %

       1                 : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
       2                 :  *
       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 Communicator client code, released
      17                 :  * March 31, 1998.
      18                 :  *
      19                 :  * The Initial Developer of the Original Code is
      20                 :  * Netscape Communications Corporation.
      21                 :  * Portions created by the Initial Developer are Copyright (C) 1998
      22                 :  * the Initial Developer. All Rights Reserved.
      23                 :  *
      24                 :  * Contributor(s):
      25                 :  *   John Bandhauer <jband@netscape.com> (original author)
      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                 : /* Code for throwing errors into JavaScript. */
      42                 : 
      43                 : #include "xpcprivate.h"
      44                 : #include "XPCWrapper.h"
      45                 : 
      46                 : JSBool XPCThrower::sVerbose = true;
      47                 : 
      48                 : // static
      49                 : void
      50              17 : XPCThrower::Throw(nsresult rv, JSContext* cx)
      51                 : {
      52                 :     const char* format;
      53              17 :     if (JS_IsExceptionPending(cx))
      54               0 :         return;
      55              17 :     if (!nsXPCException::NameAndFormatForNSResult(rv, nsnull, &format))
      56               0 :         format = "";
      57              17 :     BuildAndThrowException(cx, rv, format);
      58                 : }
      59                 : 
      60                 : /*
      61                 :  * If there has already been an exception thrown, see if we're throwing the
      62                 :  * same sort of exception, and if we are, don't clobber the old one. ccx
      63                 :  * should be the current call context.
      64                 :  */
      65                 : // static
      66                 : JSBool
      67           38278 : XPCThrower::CheckForPendingException(nsresult result, JSContext *cx)
      68                 : {
      69           38278 :     nsXPConnect* xpc = nsXPConnect::GetXPConnect();
      70           38278 :     if (!xpc)
      71               0 :         return false;
      72                 : 
      73           76556 :     nsCOMPtr<nsIException> e;
      74           38278 :     xpc->GetPendingException(getter_AddRefs(e));
      75           38278 :     if (!e)
      76           38017 :         return false;
      77             261 :     xpc->SetPendingException(nsnull);
      78                 : 
      79                 :     nsresult e_result;
      80             261 :     if (NS_FAILED(e->GetResult(&e_result)) || e_result != result)
      81              15 :         return false;
      82                 : 
      83             246 :     if (!ThrowExceptionObject(cx, e))
      84               0 :         JS_ReportOutOfMemory(cx);
      85             246 :     return true;
      86                 : }
      87                 : 
      88                 : // static
      89                 : void
      90               3 : XPCThrower::Throw(nsresult rv, XPCCallContext& ccx)
      91                 : {
      92                 :     char* sz;
      93                 :     const char* format;
      94                 : 
      95               3 :     if (CheckForPendingException(rv, ccx))
      96               0 :         return;
      97                 : 
      98               3 :     if (!nsXPCException::NameAndFormatForNSResult(rv, nsnull, &format))
      99               0 :         format = "";
     100                 : 
     101               3 :     sz = (char*) format;
     102                 : 
     103               3 :     if (sz && sVerbose)
     104               3 :         Verbosify(ccx, &sz, false);
     105                 : 
     106               3 :     BuildAndThrowException(ccx, rv, sz);
     107                 : 
     108               3 :     if (sz && sz != format)
     109               3 :         JS_smprintf_free(sz);
     110                 : }
     111                 : 
     112                 : 
     113                 : // static
     114                 : void
     115           38046 : XPCThrower::ThrowBadResult(nsresult rv, nsresult result, XPCCallContext& ccx)
     116                 : {
     117                 :     char* sz;
     118                 :     const char* format;
     119                 :     const char* name;
     120                 : 
     121                 :     /*
     122                 :     *  If there is a pending exception when the native call returns and
     123                 :     *  it has the same error result as returned by the native call, then
     124                 :     *  the native call may be passing through an error from a previous JS
     125                 :     *  call. So we'll just throw that exception into our JS.
     126                 :     */
     127                 : 
     128           38046 :     if (CheckForPendingException(result, ccx))
     129             246 :         return;
     130                 : 
     131                 :     // else...
     132                 : 
     133           37800 :     if (!nsXPCException::NameAndFormatForNSResult(rv, nsnull, &format) || !format)
     134               0 :         format = "";
     135                 : 
     136           37800 :     if (nsXPCException::NameAndFormatForNSResult(result, &name, nsnull) && name)
     137           37742 :         sz = JS_smprintf("%s 0x%x (%s)", format, result, name);
     138                 :     else
     139              58 :         sz = JS_smprintf("%s 0x%x", format, result);
     140                 : 
     141           37800 :     if (sz && sVerbose)
     142           37800 :         Verbosify(ccx, &sz, true);
     143                 : 
     144           37800 :     BuildAndThrowException(ccx, result, sz);
     145                 : 
     146           37800 :     if (sz)
     147           37800 :         JS_smprintf_free(sz);
     148                 : }
     149                 : 
     150                 : // static
     151                 : void
     152              25 : XPCThrower::ThrowBadParam(nsresult rv, unsigned paramNum, XPCCallContext& ccx)
     153                 : {
     154                 :     char* sz;
     155                 :     const char* format;
     156                 : 
     157              25 :     if (!nsXPCException::NameAndFormatForNSResult(rv, nsnull, &format))
     158               0 :         format = "";
     159                 : 
     160              25 :     sz = JS_smprintf("%s arg %d", format, paramNum);
     161                 : 
     162              25 :     if (sz && sVerbose)
     163              25 :         Verbosify(ccx, &sz, true);
     164                 : 
     165              25 :     BuildAndThrowException(ccx, rv, sz);
     166                 : 
     167              25 :     if (sz)
     168              25 :         JS_smprintf_free(sz);
     169              25 : }
     170                 : 
     171                 : 
     172                 : // static
     173                 : void
     174           37828 : XPCThrower::Verbosify(XPCCallContext& ccx,
     175                 :                       char** psz, bool own)
     176                 : {
     177           37828 :     char* sz = nsnull;
     178                 : 
     179           37828 :     if (ccx.HasInterfaceAndMember()) {
     180           37828 :         XPCNativeInterface* iface = ccx.GetInterface();
     181           37828 :         jsid id = ccx.GetMember()->GetName();
     182           75656 :         JSAutoByteString bytes;
     183           37828 :         const char *name = JSID_IS_VOID(id) ? "Unknown" : bytes.encode(ccx, JSID_TO_STRING(id));
     184           37828 :         if (!name) {
     185               0 :             name = "";
     186                 :         }
     187           37828 :         sz = JS_smprintf("%s [%s.%s]", *psz, iface->GetNameString(), name);
     188                 :     }
     189                 : 
     190           37828 :     if (sz) {
     191           37828 :         if (own)
     192           37825 :             JS_smprintf_free(*psz);
     193           37828 :         *psz = sz;
     194                 :     }
     195           37828 : }
     196                 : 
     197                 : // static
     198                 : void
     199           38074 : XPCThrower::BuildAndThrowException(JSContext* cx, nsresult rv, const char* sz)
     200                 : {
     201           38074 :     JSBool success = false;
     202                 : 
     203                 :     /* no need to set an expection if the security manager already has */
     204           38074 :     if (rv == NS_ERROR_XPC_SECURITY_MANAGER_VETO && JS_IsExceptionPending(cx))
     205               0 :         return;
     206           76148 :     nsCOMPtr<nsIException> finalException;
     207           76148 :     nsCOMPtr<nsIException> defaultException;
     208           38074 :     nsXPCException::NewException(sz, rv, nsnull, nsnull, getter_AddRefs(defaultException));
     209           38074 :     XPCPerThreadData* tls = XPCPerThreadData::GetData(cx);
     210           38074 :     if (tls) {
     211           38074 :         nsIExceptionManager * exceptionManager = tls->GetExceptionManager();
     212           38074 :         if (exceptionManager) {
     213                 :            // Ask the provider for the exception, if there is no provider
     214                 :            // we expect it to set e to null
     215                 :             exceptionManager->GetExceptionFromProvider(rv,
     216                 :                                                        defaultException,
     217           38074 :                                                        getter_AddRefs(finalException));
     218                 :             // We should get at least the defaultException back,
     219                 :             // but just in case
     220           38074 :             if (finalException == nsnull) {
     221               9 :                 finalException = defaultException;
     222                 :             }
     223                 :         }
     224                 :     }
     225                 :     // XXX Should we put the following test and call to JS_ReportOutOfMemory
     226                 :     // inside this test?
     227           38074 :     if (finalException)
     228           38074 :         success = ThrowExceptionObject(cx, finalException);
     229                 :     // If we weren't able to build or throw an exception we're
     230                 :     // most likely out of memory
     231           38074 :     if (!success)
     232               0 :         JS_ReportOutOfMemory(cx);
     233                 : }
     234                 : 
     235                 : static bool
     236           38320 : IsCallerChrome(JSContext* cx)
     237                 : {
     238                 :     nsresult rv;
     239                 : 
     240           76640 :     nsCOMPtr<nsIScriptSecurityManager> secMan;
     241           38320 :     if (XPCPerThreadData::IsMainThread(cx)) {
     242           38320 :         secMan = XPCWrapper::GetSecurityManager();
     243                 :     } else {
     244               0 :         nsXPConnect* xpc = nsXPConnect::GetXPConnect();
     245               0 :         if (!xpc)
     246               0 :             return false;
     247                 : 
     248               0 :         nsCOMPtr<nsIXPCSecurityManager> xpcSecMan;
     249               0 :         PRUint16 flags = 0;
     250               0 :         rv = xpc->GetSecurityManagerForJSContext(cx, getter_AddRefs(xpcSecMan),
     251               0 :                                                  &flags);
     252               0 :         if (NS_FAILED(rv) || !xpcSecMan)
     253               0 :             return false;
     254                 : 
     255               0 :         secMan = do_QueryInterface(xpcSecMan);
     256                 :     }
     257                 : 
     258           38320 :     if (!secMan)
     259               0 :         return false;
     260                 : 
     261                 :     bool isChrome;
     262           38320 :     rv = secMan->SubjectPrincipalIsSystem(&isChrome);
     263           38320 :     return NS_SUCCEEDED(rv) && isChrome;
     264                 : }
     265                 : 
     266                 : // static
     267                 : JSBool
     268           38320 : XPCThrower::ThrowExceptionObject(JSContext* cx, nsIException* e)
     269                 : {
     270           38320 :     JSBool success = false;
     271           38320 :     if (e) {
     272           76640 :         nsCOMPtr<nsIXPCException> xpcEx;
     273                 :         jsval thrown;
     274                 :         nsXPConnect* xpc;
     275                 : 
     276                 :         // If we stored the original thrown JS value in the exception
     277                 :         // (see XPCConvert::ConstructException) and we are in a web
     278                 :         // context (i.e., not chrome), rethrow the original value.
     279           38320 :         if (!IsCallerChrome(cx) &&
     280               0 :             (xpcEx = do_QueryInterface(e)) &&
     281               0 :             NS_SUCCEEDED(xpcEx->StealJSVal(&thrown))) {
     282               0 :             if (!JS_WrapValue(cx, &thrown))
     283               0 :                 return false;
     284               0 :             JS_SetPendingException(cx, thrown);
     285               0 :             success = true;
     286           38320 :         } else if ((xpc = nsXPConnect::GetXPConnect())) {
     287           38320 :             JSObject* glob = JS_GetGlobalForScopeChain(cx);
     288           38320 :             if (!glob)
     289               0 :                 return false;
     290                 : 
     291           76640 :             nsCOMPtr<nsIXPConnectJSObjectHolder> holder;
     292                 :             nsresult rv = xpc->WrapNative(cx, glob, e,
     293                 :                                           NS_GET_IID(nsIException),
     294           38320 :                                           getter_AddRefs(holder));
     295           38320 :             if (NS_SUCCEEDED(rv) && holder) {
     296                 :                 JSObject* obj;
     297           38320 :                 if (NS_SUCCEEDED(holder->GetJSObject(&obj))) {
     298           38320 :                     JS_SetPendingException(cx, OBJECT_TO_JSVAL(obj));
     299           38320 :                     success = true;
     300                 :                 }
     301                 :             }
     302                 :         }
     303                 :     }
     304           38320 :     return success;
     305                 : }

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