Mercurial > pub > dyncall > dyncall

comparison dynload/dynload_syms_mach-o.c @ 0:3e629dc19168

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
initial from svn dyncall-1745
author Daniel Adler
date Thu, 19 Mar 2015 22:24:28 +0100
parents
children 87c695673522
comparison
equal deleted inserted replaced
-1:000000000000 0:3e629dc19168
1 /*
2
3 Package: dyncall
4 Library: dynload
5 File: dynload/dynload_syms_mach-o.c
6 Description:
7 License:
8
9 Copyright (c) 2007-2015 Olivier Chafik <olivier.chafik@gmail.com>
10
11 Permission to use, copy, modify, and distribute this software for any
12 purpose with or without fee is hereby granted, provided that the above
13 copyright notice and this permission notice appear in all copies.
14
15 THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
16 WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
17 MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
18 ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
19 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
20 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
21 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22
23 */
24
25
26
27 /*
28
29 dynamic symbol resolver for Mach-O
30
31 */
32
33 #include "dynload.h"
34 #include "dynload_alloc.h"
35
36 #include <mach-o/dyld.h>
37 #include <mach-o/nlist.h>
38 #include <dlfcn.h>
39 #include <string.h>
40
41 #if defined(ARCH_X64) //@@@ use dyncall_macros.h
42 #define MACH_HEADER_TYPE mach_header_64
43 #define SEGMENT_COMMAND segment_command_64
44 #define NLIST_TYPE nlist_64
45 #else
46 #define MACH_HEADER_TYPE mach_header
47 #define SEGMENT_COMMAND segment_command
48 #define NLIST_TYPE nlist
49 #endif
50
51
52 struct DLLib_
53 {
54 char* libPath;
55 void* handle;
56 };
57
58
59 struct DLSyms_
60 {
61 const char* pStringTable;
62 const struct NLIST_TYPE* pSymbolTable;
63 uint32_t symbolCount;
64 };
65
66
67 DLSyms* dlSymsInit(const char* libPath)
68 {
69 DLSyms* pSyms = NULL;
70 uint32_t iImage, nImages;
71 for (iImage = 0, nImages = _dyld_image_count(); iImage < nImages; iImage++)
72 {
73 const char* name = _dyld_get_image_name(iImage);
74 if (name && !strcmp(name, libPath))
75 {
76 const struct MACH_HEADER_TYPE* pHeader = (const struct MACH_HEADER_TYPE*) _dyld_get_image_header(iImage);
77 const char* pBase = ((const char*)pHeader);
78 if (pHeader->filetype != MH_DYLIB)
79 return NULL;
80 if (pHeader->flags & MH_SPLIT_SEGS)
81 return NULL;
82
83 if (pHeader)
84 {
85 uint32_t iCmd, nCmds = pHeader->ncmds;
86 const struct load_command* cmd = (const struct load_command*)(pBase + sizeof(struct MACH_HEADER_TYPE));
87
88 for (iCmd = 0; iCmd < nCmds; iCmd++)
89 {
90 if (cmd->cmd == LC_SYMTAB)
91 {
92 const struct symtab_command* scmd = (const struct symtab_command*)cmd;
93
94 pSyms = (DLSyms*)( dlAllocMem(sizeof(DLSyms)) );
95 pSyms->symbolCount = scmd->nsyms;
96 pSyms->pStringTable = pBase + scmd->stroff;
97 pSyms->pSymbolTable = (struct NLIST_TYPE*)(pBase + scmd->symoff);
98
99 return pSyms;
100 }
101 cmd = (const struct load_command*)(((char*)cmd) + cmd->cmdsize);
102 }
103 }
104 break;
105 }
106 }
107 return NULL;
108 }
109
110
111 void dlSymsCleanup(DLSyms* pSyms)
112 {
113 if (!pSyms)
114 return;
115
116 dlFreeMem(pSyms);
117 }
118
119 int dlSymsCount(DLSyms* pSyms)
120 {
121 if (!pSyms)
122 return 0;
123 return pSyms->symbolCount;
124 }
125
126 static const struct NLIST_TYPE* get_nlist(DLSyms* pSyms, int index)
127 {
128 const struct NLIST_TYPE* nl;
129 if (!pSyms)
130 return NULL;
131
132 nl = pSyms->pSymbolTable + index;
133 if (nl->n_un.n_strx <= 1)
134 return NULL; // would be empty string anyway
135
136 //TODO skip more symbols based on nl->n_desc and nl->n_type ?
137 return nl;
138 }
139
140
141 const char* dlSymsName(DLSyms* pSyms, int index)
142 {
143 const struct NLIST_TYPE* nl = get_nlist(pSyms, index);
144 if (!nl)
145 return NULL;
146
147 return pSyms->pStringTable + nl->n_un.n_strx;
148 }
149
150
151 void* dlSymsValue(DLSyms* pSyms, int index)
152 {
153 const struct NLIST_TYPE* nl = get_nlist(pSyms, index);
154 if (!nl)
155 return NULL;
156
157 return (void*) (ptrdiff_t) (nl->n_value);
158 }
159
160
161 const char* dlSymsNameFromValue(DLSyms* pSyms, void* value)
162 {
163 Dl_info info;
164 if (!dladdr(value, &info) || (value != info.dli_saddr))
165 return NULL;
166
167 return info.dli_sname;
168 }