runtime/objc-file.mm

   1 /*
   2  * Copyright (c) 1999-2007 Apple Inc.  All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #if __OBJC2__
  25
  26 #include "objc-private.h"
  27 #include "objc-file.h"
  28
  29
  30 // Look for a __DATA or __DATA_CONST or __DATA_DIRTY section
  31 // with the given name that stores an array of T.
  32 template <typename T>
  33 T* getDataSection(const headerType *mhdr, const char *sectname,
  34                   size_t *outBytes, size_t *outCount)
  35 {
  36     unsigned long byteCount = 0;
  37     T* data = (T*)getsectiondata(mhdr, "__DATA", sectname, &byteCount);
  38     if (!data) {
  39         data = (T*)getsectiondata(mhdr, "__DATA_CONST", sectname, &byteCount);
  40     }
  41     if (!data) {
  42         data = (T*)getsectiondata(mhdr, "__DATA_DIRTY", sectname, &byteCount);
  43     }
  44     if (outBytes) *outBytes = byteCount;
  45     if (outCount) *outCount = byteCount / sizeof(T);
  46     return data;
  47 }
  48
  49 #define GETSECT(name, type, sectname)                                   \
  50     type *name(const headerType *mhdr, size_t *outCount) {              \
  51         return getDataSection<type>(mhdr, sectname, nil, outCount);     \
  52     }                                                                   \
  53     type *name(const header_info *hi, size_t *outCount) {               \
  54         return getDataSection<type>(hi->mhdr(), sectname, nil, outCount); \
  55     }
  56
  57 //      function name                 content type     section name
  58 GETSECT(_getObjc2SelectorRefs,        SEL,             "__objc_selrefs");
  59 GETSECT(_getObjc2MessageRefs,         message_ref_t,   "__objc_msgrefs");
  60 GETSECT(_getObjc2ClassRefs,           Class,           "__objc_classrefs");
  61 GETSECT(_getObjc2SuperRefs,           Class,           "__objc_superrefs");
  62 GETSECT(_getObjc2ClassList,           classref_t const,      "__objc_classlist");
  63 GETSECT(_getObjc2NonlazyClassList,    classref_t const,      "__objc_nlclslist");
  64 GETSECT(_getObjc2CategoryList,        category_t * const,    "__objc_catlist");
  65 GETSECT(_getObjc2CategoryList2,       category_t * const,    "__objc_catlist2");
  66 GETSECT(_getObjc2NonlazyCategoryList, category_t * const,    "__objc_nlcatlist");
  67 GETSECT(_getObjc2ProtocolList,        protocol_t * const,    "__objc_protolist");
  68 GETSECT(_getObjc2ProtocolRefs,        protocol_t *,    "__objc_protorefs");
  69 GETSECT(getLibobjcInitializers,       UnsignedInitializer, "__objc_init_func");
  70
  71 uint32_t *getLibobjcInitializerOffsets(const headerType *mhdr, size_t *outCount) {
  72     unsigned long byteCount = 0;
  73     uint32_t *offsets = (uint32_t *)getsectiondata(mhdr, "__TEXT", "__objc_init_offs", &byteCount);
  74     if (outCount) *outCount = byteCount / sizeof(uint32_t);
  75     return offsets;
  76 }
  77
  78 objc_image_info *
  79 _getObjcImageInfo(const headerType *mhdr, size_t *outBytes)
  80 {
  81     return getDataSection<objc_image_info>(mhdr, "__objc_imageinfo",
  82                                            outBytes, nil);
  83 }
  84
  85 // Look for an __objc* section other than __objc_imageinfo
  86 static bool segmentHasObjcContents(const segmentType *seg)
  87 {
  88     for (uint32_t i = 0; i < seg->nsects; i++) {
  89         const sectionType *sect = ((const sectionType *)(seg+1))+i;
  90         if (sectnameStartsWith(sect->sectname, "__objc_")  &&
  91             !sectnameEquals(sect->sectname, "__objc_imageinfo"))
  92         {
  93             return true;
  94         }
  95     }
  96
  97     return false;
  98 }
  99
 100 // Look for an __objc* section other than __objc_imageinfo
 101 bool
 102 _hasObjcContents(const header_info *hi)
 103 {
 104     bool foundObjC = false;
 105
 106     foreach_data_segment(hi->mhdr(), [&](const segmentType *seg, intptr_t slide)
 107     {
 108         if (segmentHasObjcContents(seg)) foundObjC = true;
 109     });
 110
 111     return foundObjC;
 112
 113 }
 114
 115
 116 // OBJC2
 117 #endif