1 /* simple-object-common.h -- common structs for object file manipulation.
2 Copyright (C) 2010-2023 Free Software Foundation, Inc.
3
4 This file is part of the libiberty library.
5 Libiberty is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public
7 License as published by the Free Software Foundation; either
8 version 2 of the License, or (at your option) any later version.
9
10 Libiberty is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
14
15 You should have received a copy of the GNU Library General Public
16 License along with libiberty; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
18 Boston, MA 02110-1301, USA. */
19
20 /* Forward reference. */
21 struct simple_object_functions;
22
23 /* An object file opened for reading. */
24
25 struct simple_object_read_struct
26 {
27 /* The file descriptor. */
28 int descriptor;
29 /* The offset within the file. */
30 off_t offset;
31 /* The functions which do the actual work. */
32 const struct simple_object_functions *functions;
33 /* Private data for the object file format. */
34 void *data;
35 };
36
37 /* Object file attributes. */
38
39 struct simple_object_attributes_struct
40 {
41 /* The functions which do the actual work. */
42 const struct simple_object_functions *functions;
43 /* Private data for the object file format. */
44 void *data;
45 };
46
47 /* An object file being created. */
48
49 struct simple_object_write_struct
50 {
51 /* The functions which do the actual work. */
52 const struct simple_object_functions *functions;
53 /* The segment_name argument from the user. */
54 char *segment_name;
55 /* The start of the list of sections. */
56 simple_object_write_section *sections;
57 /* The last entry in the list of sections. */
58 simple_object_write_section *last_section;
59 /* Private data for the object file format. */
60 void *data;
61 };
62
63 /* A section in an object file being created. */
64
65 struct simple_object_write_section_struct
66 {
67 /* Next in the list of sections attached to an
68 simple_object_write. */
69 simple_object_write_section *next;
70 /* The name of this section. */
71 char *name;
72 /* The required alignment. */
73 unsigned int align;
74 /* The first data attached to this section. */
75 struct simple_object_write_section_buffer *buffers;
76 /* The last data attached to this section. */
77 struct simple_object_write_section_buffer *last_buffer;
78 };
79
80 /* Data attached to a section. */
81
82 struct simple_object_write_section_buffer
83 {
84 /* The next data for this section. */
85 struct simple_object_write_section_buffer *next;
86 /* The size of the buffer. */
87 size_t size;
88 /* The actual bytes. */
89 const void *buffer;
90 /* A buffer to free, or NULL. */
91 void *free_buffer;
92 };
93
94 /* The number of bytes we read from the start of the file to pass to
95 the match function. */
96 #define SIMPLE_OBJECT_MATCH_HEADER_LEN (16)
97
98 /* Format-specific object file functions. */
99
100 struct simple_object_functions
101 {
102 /* If this file matches these functions, return a new value for the
103 private data for an simple_object_read. HEADER is the first 16
104 bytes of the file. DESCRIPTOR, OFFSET, SEGMENT_NAME, ERRMSG, and
105 ERR are as for simple_object_open_read. If this file does not
106 match, this function should return NULL with *ERRMSG set to
107 NULL. */
108 void *(*match) (unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN],
109 int descriptor, off_t offset, const char *segment_name,
110 const char **errmsg, int *err);
111
112 /* Implement simple_object_find_sections. */
113 const char *(*find_sections) (simple_object_read *,
114 int (*pfn) (void *, const char *,
115 off_t offset, off_t length),
116 void *data,
117 int *err);
118
119 /* Return the private data for the attributes for SOBJ. */
120 void *(*fetch_attributes) (simple_object_read *sobj, const char **errmsg,
121 int *err);
122
123 /* Release the private data for an simple_object_read. */
124 void (*release_read) (void *);
125
126 /* Merge the private data for the attributes of two files. If they
127 could be linked together, return NULL. Otherwise return an error
128 message. */
129 const char *(*attributes_merge) (void *, void *, int *err);
130
131 /* Release the private data for an simple_object_attributes. */
132 void (*release_attributes) (void *);
133
134 /* Start creating an object file. */
135 void *(*start_write) (void *attributes_data, const char **errmsg,
136 int *err);
137
138 /* Write the complete object file. */
139 const char *(*write_to_file) (simple_object_write *sobj, int descriptor,
140 int *err);
141
142 /* Release the private data for an simple_object_write. */
143 void (*release_write) (void *);
144
145 /* Copy LTO debug sections. */
146 const char *(*copy_lto_debug_sections) (simple_object_read *sobj,
147 simple_object_write *dobj,
148 char *(*pfn) (const char *),
149 int *err);
150 };
151
152 /* The known object file formats. */
153
154 extern const struct simple_object_functions simple_object_coff_functions;
155 extern const struct simple_object_functions simple_object_elf_functions;
156 extern const struct simple_object_functions simple_object_mach_o_functions;
157 extern const struct simple_object_functions simple_object_xcoff_functions;
158
159 /* Read SIZE bytes from DESCRIPTOR at file offset OFFSET into BUFFER.
160 Return non-zero on success. On failure return 0 and set *ERRMSG
161 and *ERR. */
162
163 extern int
164 simple_object_internal_read (int descriptor, off_t offset,
165 unsigned char *buffer, size_t size,
166 const char **errmsg, int *err);
167
168 /* Write SIZE bytes from BUFFER to DESCRIPTOR at file offset OFFSET.
169 Return non-zero on success. On failure return 0 and set *ERRMSG
170 and *ERR. */
171
172 extern int
173 simple_object_internal_write (int descriptor, off_t offset,
174 const unsigned char *buffer, size_t size,
175 const char **errmsg, int *err);
176
177 /* Define ulong_type as an unsigned 64-bit type if available.
178 Otherwise just make it unsigned long. */
179
180 #ifdef UNSIGNED_64BIT_TYPE
181 __extension__ typedef UNSIGNED_64BIT_TYPE ulong_type;
182 #else
183 typedef unsigned long ulong_type;
184 #endif
185
186 /* Fetch a big-endian 16-bit value. */
187
188 static inline unsigned short
189 simple_object_fetch_big_16 (const unsigned char *buf)
190 {
191 return ((unsigned short) buf[0] << 8) | (unsigned short) buf[1];
192 }
193
194 /* Fetch a little-endian 16-bit value. */
195
196 static inline unsigned short
197 simple_object_fetch_little_16 (const unsigned char *buf)
198 {
199 return ((unsigned short) buf[1] << 8) | (unsigned short) buf[0];
200 }
201
202 /* Fetch a big-endian 32-bit value. */
203
204 static inline unsigned int
205 simple_object_fetch_big_32 (const unsigned char *buf)
206 {
207 return (((unsigned int) buf[0] << 24)
208 | ((unsigned int) buf[1] << 16)
209 | ((unsigned int) buf[2] << 8)
210 | (unsigned int) buf[3]);
211 }
212
213 /* Fetch a little-endian 32-bit value. */
214
215 static inline unsigned int
216 simple_object_fetch_little_32 (const unsigned char *buf)
217 {
218 return (((unsigned int) buf[3] << 24)
219 | ((unsigned int) buf[2] << 16)
220 | ((unsigned int) buf[1] << 8)
221 | (unsigned int) buf[0]);
222 }
223
224 /* Fetch a big-endian 32-bit value as a ulong_type. */
225
226 static inline ulong_type
227 simple_object_fetch_big_32_ulong (const unsigned char *buf)
228 {
229 return (ulong_type) simple_object_fetch_big_32 (buf);
230 }
231
232 /* Fetch a little-endian 32-bit value as a ulong_type. */
233
234 static inline ulong_type
235 simple_object_fetch_little_32_ulong (const unsigned char *buf)
236 {
237 return (ulong_type) simple_object_fetch_little_32 (buf);
238 }
239
240 #ifdef UNSIGNED_64BIT_TYPE
241
242 /* Fetch a big-endian 64-bit value. */
243
244 static inline ulong_type
245 simple_object_fetch_big_64 (const unsigned char *buf)
246 {
247 return (((ulong_type) buf[0] << 56)
248 | ((ulong_type) buf[1] << 48)
249 | ((ulong_type) buf[2] << 40)
250 | ((ulong_type) buf[3] << 32)
251 | ((ulong_type) buf[4] << 24)
252 | ((ulong_type) buf[5] << 16)
253 | ((ulong_type) buf[6] << 8)
254 | (ulong_type) buf[7]);
255 }
256
257 /* Fetch a little-endian 64-bit value. */
258
259 static inline ulong_type
260 simple_object_fetch_little_64 (const unsigned char *buf)
261 {
262 return (((ulong_type) buf[7] << 56)
263 | ((ulong_type) buf[6] << 48)
264 | ((ulong_type) buf[5] << 40)
265 | ((ulong_type) buf[4] << 32)
266 | ((ulong_type) buf[3] << 24)
267 | ((ulong_type) buf[2] << 16)
268 | ((ulong_type) buf[1] << 8)
269 | (ulong_type) buf[0]);
270 }
271
272 #endif
273
274 /* Store a big-endian 16-bit value. */
275
276 static inline void
277 simple_object_set_big_16 (unsigned char *buf, unsigned short val)
278 {
279 buf[0] = (val >> 8) & 0xff;
280 buf[1] = val & 0xff;
281 }
282
283 /* Store a little-endian 16-bit value. */
284
285 static inline void
286 simple_object_set_little_16 (unsigned char *buf, unsigned short val)
287 {
288 buf[1] = (val >> 8) & 0xff;
289 buf[0] = val & 0xff;
290 }
291
292 /* Store a big-endian 32-bit value. */
293
294 static inline void
295 simple_object_set_big_32 (unsigned char *buf, unsigned int val)
296 {
297 buf[0] = (val >> 24) & 0xff;
298 buf[1] = (val >> 16) & 0xff;
299 buf[2] = (val >> 8) & 0xff;
300 buf[3] = val & 0xff;
301 }
302
303 /* Store a little-endian 32-bit value. */
304
305 static inline void
306 simple_object_set_little_32 (unsigned char *buf, unsigned int val)
307 {
308 buf[3] = (val >> 24) & 0xff;
309 buf[2] = (val >> 16) & 0xff;
310 buf[1] = (val >> 8) & 0xff;
311 buf[0] = val & 0xff;
312 }
313
314 /* Store a big-endian 32-bit value coming in as a ulong_type. */
315
316 static inline void
317 simple_object_set_big_32_ulong (unsigned char *buf, ulong_type val)
318 {
319 simple_object_set_big_32 (buf, val);
320 }
321
322 /* Store a little-endian 32-bit value coming in as a ulong_type. */
323
324 static inline void
325 simple_object_set_little_32_ulong (unsigned char *buf, ulong_type val)
326 {
327 simple_object_set_little_32 (buf, val);
328 }
329
330 #ifdef UNSIGNED_64BIT_TYPE
331
332 /* Store a big-endian 64-bit value. */
333
334 static inline void
335 simple_object_set_big_64 (unsigned char *buf, ulong_type val)
336 {
337 buf[0] = (val >> 56) & 0xff;
338 buf[1] = (val >> 48) & 0xff;
339 buf[2] = (val >> 40) & 0xff;
340 buf[3] = (val >> 32) & 0xff;
341 buf[4] = (val >> 24) & 0xff;
342 buf[5] = (val >> 16) & 0xff;
343 buf[6] = (val >> 8) & 0xff;
344 buf[7] = val & 0xff;
345 }
346
347 /* Store a little-endian 64-bit value. */
348
349 static inline void
350 simple_object_set_little_64 (unsigned char *buf, ulong_type val)
351 {
352 buf[7] = (val >> 56) & 0xff;
353 buf[6] = (val >> 48) & 0xff;
354 buf[5] = (val >> 40) & 0xff;
355 buf[4] = (val >> 32) & 0xff;
356 buf[3] = (val >> 24) & 0xff;
357 buf[2] = (val >> 16) & 0xff;
358 buf[1] = (val >> 8) & 0xff;
359 buf[0] = val & 0xff;
360 }
361
362 #endif