xpcom/glue/standalone/nsGlueLinkingDlopen.cpp

   1 /* -*- Mode: C++; tab-width: 6; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is Mozilla XPCOM.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Benjamin Smedberg <benjamin@smedbergs.us>
  19  *
  20  * Portions created by the Initial Developer are Copyright (C) 2005
  21  * the Initial Developer. All Rights Reserved.
  22  *
  23  * Contributor(s):
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
  27  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
  29  * of those above. If you wish to allow use of your version of this file only
  30  * under the terms of either the GPL or the LGPL, and not to allow others to
  31  * use your version of this file under the terms of the MPL, indicate your
  32  * decision by deleting the provisions above and replace them with the notice
  33  * and other provisions required by the GPL or the LGPL. If you do not delete
  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #include "nsGlueLinking.h"
  40 #include "nsXPCOMGlue.h"
  41
  42 #include <dlfcn.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <stdio.h>
  46
  47 #if defined(SUNOS4) || defined(NEXTSTEP) || \
  48     (defined(OPENBSD) || defined(NETBSD)) && !defined(__ELF__)
  49 #define LEADING_UNDERSCORE "_"
  50 #else
  51 #define LEADING_UNDERSCORE
  52 #endif
  53
  54 struct DependentLib
  55 {
  56     void         *libHandle;
  57     DependentLib *next;
  58 };
  59
  60 static DependentLib *sTop;
  61 static void* sXULLibHandle;
  62
  63 static void
  64 AppendDependentLib(void *libHandle)
  65 {
  66     DependentLib *d = new DependentLib;
  67     if (!d)
  68         return;
  69
  70     d->next = sTop;
  71     d->libHandle = libHandle;
  72
  73     sTop = d;
  74 }
  75
  76 static void
  77 ReadDependentCB(const char *aDependentLib)
  78 {
  79     void *libHandle = dlopen(aDependentLib, RTLD_GLOBAL | RTLD_LAZY);
  80     if (!libHandle)
  81         return;
  82
  83     AppendDependentLib(libHandle);
  84 }
  85
  86 GetFrozenFunctionsFunc
  87 XPCOMGlueLoad(const char *xpcomFile)
  88 {
  89     char xpcomDir[MAXPATHLEN];
  90     if (realpath(xpcomFile, xpcomDir)) {
  91         char *lastSlash = strrchr(xpcomDir, '/');
  92         if (lastSlash) {
  93             *lastSlash = '\0';
  94
  95             XPCOMGlueLoadDependentLibs(xpcomDir, ReadDependentCB);
  96
  97             snprintf(lastSlash, MAXPATHLEN - strlen(xpcomDir), "/" XUL_DLL);
  98
  99             sXULLibHandle = dlopen(xpcomDir, RTLD_GLOBAL | RTLD_LAZY);
 100         }
 101     }
 102
 103     // RTLD_DEFAULT is not defined in non-GNU toolchains, and it is
 104     // (void*) 0 in any case.
 105
 106     void *libHandle = nsnull;
 107
 108     if (xpcomFile[0] != '.' || xpcomFile[1] != '\0') {
 109         libHandle = dlopen(xpcomFile, RTLD_GLOBAL | RTLD_LAZY);
 110         if (libHandle) {
 111             AppendDependentLib(libHandle);
 112         }
 113     }
 114
 115     GetFrozenFunctionsFunc sym =
 116         (GetFrozenFunctionsFunc) dlsym(libHandle,
 117                                        LEADING_UNDERSCORE "NS_GetFrozenFunctions");
 118
 119     if (!sym)
 120         XPCOMGlueUnload();
 121
 122     return sym;
 123 }
 124
 125 void
 126 XPCOMGlueUnload()
 127 {
 128     while (sTop) {
 129         dlclose(sTop->libHandle);
 130
 131         DependentLib *temp = sTop;
 132         sTop = sTop->next;
 133
 134         delete temp;
 135     }
 136
 137     if (sXULLibHandle) {
 138         dlclose(sXULLibHandle);
 139         sXULLibHandle = nsnull;
 140     }
 141 }
 142
 143 nsresult
 144 XPCOMGlueLoadXULFunctions(const nsDynamicFunctionLoad *symbols)
 145 {
 146     // We don't null-check sXULLibHandle because this might work even
 147     // if it is null (same as RTLD_DEFAULT)
 148
 149     nsresult rv = NS_OK;
 150     while (symbols->functionName) {
 151         char buffer[512];
 152         snprintf(buffer, sizeof(buffer),
 153                  LEADING_UNDERSCORE "%s", symbols->functionName);
 154
 155         *symbols->function = (NSFuncPtr) dlsym(sXULLibHandle, buffer);
 156         if (!*symbols->function)
 157             rv = NS_ERROR_LOSS_OF_SIGNIFICANT_DATA;
 158
 159         ++symbols;
 160     }
 161     return rv;
 162 }