runtime/objc-load.m

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25
  26 /*
  27  *      objc-load.m
  28  *      Copyright 1988-1996, NeXT Software, Inc.
  29  *      Author: s. naroff
  30  *
  31  */
  32
  33 #import "objc-private.h"
  34 #import <objc/objc-runtime.h>
  35 #import <objc/hashtable2.h>
  36 #import <objc/Object.h>
  37 #import <objc/Protocol.h>
  38
  39 //#import <streams/streams.h>
  40
  41 #include <mach-o/dyld.h>
  42
  43
  44
  45
  46 extern char *   getsectdatafromheader   (const headerType * mhp, const char * segname, const char * sectname,  int * size);
  47
  48 /* Private extern */
  49 OBJC_EXPORT void (*callbackFunction)( Class, const char * );
  50
  51
  52 struct objc_method_list **get_base_method_list(Class cls) {
  53     struct objc_method_list **ptr = ((struct objc_class * )cls)->methodLists;
  54     if (!*ptr) return NULL;
  55     while ( *ptr != 0 && *ptr != END_OF_METHODS_LIST ) { ptr++; }
  56     --ptr;
  57     return ptr;
  58 }
  59
  60
  61 /**********************************************************************************
  62 * objc_loadModule.
  63 *
  64 * NOTE: Loading isn't really thread safe.  If a load message recursively calls
  65 * objc_loadModules() both sets will be loaded correctly, but if the original
  66 * caller calls objc_unloadModules() it will probably unload the wrong modules.
  67 * If a load message calls objc_unloadModules(), then it will unload
  68 * the modules currently being loaded, which will probably cause a crash.
  69 *
  70 * Error handling is still somewhat crude.  If we encounter errors while
  71 * linking up classes or categories, we will not recover correctly.
  72 *
  73 * I removed attempts to lock the class hashtable, since this introduced
  74 * deadlock which was hard to remove.  The only way you can get into trouble
  75 * is if one thread loads a module while another thread tries to access the
  76 * loaded classes (using objc_lookUpClass) before the load is complete.
  77 **********************************************************************************/
  78 int objc_loadModule(const char *moduleName, void (*class_callback) (Class, const char *categoryName), int *errorCode)
  79 {
  80     int                                                         successFlag = 1;
  81     int                                                         locErrorCode;
  82     NSObjectFileImage                           objectFileImage;
  83     NSObjectFileImageReturnCode         code;
  84
  85     // So we don't have to check this everywhere
  86     if (errorCode == NULL)
  87         errorCode = &locErrorCode;
  88
  89     if (moduleName == NULL)
  90     {
  91         *errorCode = NSObjectFileImageInappropriateFile;
  92         return 0;
  93     }
  94
  95     if (_dyld_present () == 0)
  96     {
  97         *errorCode = NSObjectFileImageFailure;
  98         return 0;
  99     }
 100
 101     callbackFunction = class_callback;
 102     code = NSCreateObjectFileImageFromFile (moduleName, &objectFileImage);
 103     if (code != NSObjectFileImageSuccess)
 104     {
 105         *errorCode = code;
 106         return 0;
 107     }
 108
 109     if (NSLinkModule(objectFileImage, moduleName, NSLINKMODULE_OPTION_RETURN_ON_ERROR) == NULL) {
 110         NSLinkEditErrors error;
 111         int errorNum;
 112         char *fileName, *errorString;
 113         NSLinkEditError(&error, &errorNum, &fileName, &errorString);
 114         // These errors may overlap with other errors that objc_loadModule returns in other failure cases.
 115         *errorCode = error;
 116         return 0;
 117     }
 118     callbackFunction = NULL;
 119
 120
 121     return successFlag;
 122 }
 123
 124 /**********************************************************************************
 125 * objc_loadModules.
 126 **********************************************************************************/
 127 /* Lock for dynamic loading and unloading. */
 128 //      static OBJC_DECLARE_LOCK (loadLock);
 129
 130
 131 long    objc_loadModules   (char *                      modlist[],
 132                          void *                 errStream,
 133                          void                   (*class_callback) (Class, const char *),
 134                          headerType **  hdr_addr,
 135                          char *                 debug_file)
 136 {
 137     char **                             modules;
 138     int                                 code;
 139     int                                 itWorked;
 140
 141     if (modlist == 0)
 142         return 0;
 143
 144     for (modules = &modlist[0]; *modules != 0; modules++)
 145     {
 146         itWorked = objc_loadModule (*modules, class_callback, &code);
 147         if (itWorked == 0)
 148         {
 149             //if (errStream)
 150             //  NXPrintf ((NXStream *) errStream, "objc_loadModules(%s) code = %d\n", *modules, code);
 151             return 1;
 152         }
 153
 154         if (hdr_addr)
 155             *(hdr_addr++) = 0;
 156     }
 157
 158     return 0;
 159 }
 160
 161 /**********************************************************************************
 162 * objc_unloadModules.
 163 *
 164 * NOTE:  Unloading isn't really thread safe.  If an unload message calls
 165 * objc_loadModules() or objc_unloadModules(), then the current call
 166 * to objc_unloadModules() will probably unload the wrong stuff.
 167 **********************************************************************************/
 168
 169 long    objc_unloadModules (void *                      errStream,
 170                          void                   (*unload_callback) (Class, Category))
 171 {
 172     headerType *        header_addr = 0;
 173     int errflag = 0;
 174
 175     // TODO: to make unloading work, should get the current header
 176
 177     if (header_addr)
 178     {
 179         ; // TODO: unload the current header
 180     }
 181     else
 182     {
 183         errflag = 1;
 184     }
 185
 186     return errflag;
 187 }
 188