runtime/objc-load.m

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24
  25 /*
  26  *      objc-load.m
  27  *      Copyright 1988-1996, NeXT Software, Inc.
  28  *      Author: s. naroff
  29  *
  30  */
  31
  32 #import "objc-private.h"
  33 #import <objc/objc-runtime.h>
  34 #import <objc/hashtable2.h>
  35 #import <objc/Object.h>
  36 #import <objc/Protocol.h>
  37
  38 //#import <streams/streams.h>
  39
  40 #include <mach-o/dyld.h>
  41
  42
  43
  44
  45 extern char *   getsectdatafromheader   (const headerType * mhp, const char * segname, const char * sectname,  int * size);
  46
  47 /* Private extern */
  48 OBJC_EXPORT void (*callbackFunction)( Class, const char * );
  49
  50
  51 struct objc_method_list **get_base_method_list(Class cls) {
  52     struct objc_method_list **ptr = ((struct objc_class * )cls)->methodLists;
  53     if (!*ptr) return NULL;
  54     while ( *ptr != 0 && *ptr != END_OF_METHODS_LIST ) { ptr++; }
  55     --ptr;
  56     return ptr;
  57 }
  58
  59
  60 /**********************************************************************************
  61 * objc_loadModule.
  62 *
  63 * NOTE: Loading isn't really thread safe.  If a load message recursively calls
  64 * objc_loadModules() both sets will be loaded correctly, but if the original
  65 * caller calls objc_unloadModules() it will probably unload the wrong modules.
  66 * If a load message calls objc_unloadModules(), then it will unload
  67 * the modules currently being loaded, which will probably cause a crash.
  68 *
  69 * Error handling is still somewhat crude.  If we encounter errors while
  70 * linking up classes or categories, we will not recover correctly.
  71 *
  72 * I removed attempts to lock the class hashtable, since this introduced
  73 * deadlock which was hard to remove.  The only way you can get into trouble
  74 * is if one thread loads a module while another thread tries to access the
  75 * loaded classes (using objc_lookUpClass) before the load is complete.
  76 **********************************************************************************/
  77 int objc_loadModule(const char *moduleName, void (*class_callback) (Class, const char *categoryName), int *errorCode)
  78 {
  79     int                                                         successFlag = 1;
  80     int                                                         locErrorCode;
  81     NSObjectFileImage                           objectFileImage;
  82     NSObjectFileImageReturnCode         code;
  83
  84     // So we don't have to check this everywhere
  85     if (errorCode == NULL)
  86         errorCode = &locErrorCode;
  87
  88     if (moduleName == NULL)
  89     {
  90         *errorCode = NSObjectFileImageInappropriateFile;
  91         return 0;
  92     }
  93
  94     if (_dyld_present () == 0)
  95     {
  96         *errorCode = NSObjectFileImageFailure;
  97         return 0;
  98     }
  99
 100     callbackFunction = class_callback;
 101     code = NSCreateObjectFileImageFromFile (moduleName, &objectFileImage);
 102     if (code != NSObjectFileImageSuccess)
 103     {
 104         *errorCode = code;
 105         return 0;
 106     }
 107
 108     if (NSLinkModule(objectFileImage, moduleName, NSLINKMODULE_OPTION_RETURN_ON_ERROR) == NULL) {
 109         NSLinkEditErrors error;
 110         int errorNum;
 111         char *fileName, *errorString;
 112         NSLinkEditError(&error, &errorNum, &fileName, &errorString);
 113         // These errors may overlap with other errors that objc_loadModule returns in other failure cases.
 114         *errorCode = error;
 115         return 0;
 116     }
 117     callbackFunction = NULL;
 118
 119
 120     return successFlag;
 121 }
 122
 123 /**********************************************************************************
 124 * objc_loadModules.
 125 **********************************************************************************/
 126 /* Lock for dynamic loading and unloading. */
 127 //      static OBJC_DECLARE_LOCK (loadLock);
 128
 129
 130 long    objc_loadModules   (char *                      modlist[],
 131                          void *                 errStream,
 132                          void                   (*class_callback) (Class, const char *),
 133                          headerType **  hdr_addr,
 134                          char *                 debug_file)
 135 {
 136     char **                             modules;
 137     int                                 code;
 138     int                                 itWorked;
 139
 140     if (modlist == 0)
 141         return 0;
 142
 143     for (modules = &modlist[0]; *modules != 0; modules++)
 144     {
 145         itWorked = objc_loadModule (*modules, class_callback, &code);
 146         if (itWorked == 0)
 147         {
 148             //if (errStream)
 149             //  NXPrintf ((NXStream *) errStream, "objc_loadModules(%s) code = %d\n", *modules, code);
 150             return 1;
 151         }
 152
 153         if (hdr_addr)
 154             *(hdr_addr++) = 0;
 155     }
 156
 157     return 0;
 158 }
 159
 160 /**********************************************************************************
 161 * objc_unloadModules.
 162 *
 163 * NOTE:  Unloading isn't really thread safe.  If an unload message calls
 164 * objc_loadModules() or objc_unloadModules(), then the current call
 165 * to objc_unloadModules() will probably unload the wrong stuff.
 166 **********************************************************************************/
 167
 168 long    objc_unloadModules (void *                      errStream,
 169                          void                   (*unload_callback) (Class, Category))
 170 {
 171     headerType *        header_addr = 0;
 172     int errflag = 0;
 173
 174     // TODO: to make unloading work, should get the current header
 175
 176     if (header_addr)
 177     {
 178         ; // TODO: unload the current header
 179     }
 180     else
 181     {
 182         errflag = 1;
 183     }
 184
 185     return errflag;
 186 }
 187