1 /* simple-object-common.h -- common structs for object file manipulation.
2    Copyright (C) 2010 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 
146 /* The known object file formats.  */
147 
148 extern const struct simple_object_functions simple_object_coff_functions;
149 extern const struct simple_object_functions simple_object_elf_functions;
150 extern const struct simple_object_functions simple_object_mach_o_functions;
151 extern const struct simple_object_functions simple_object_xcoff_functions;
152 
153 /* Read SIZE bytes from DESCRIPTOR at file offset OFFSET into BUFFER.
154    Return non-zero on success.  On failure return 0 and set *ERRMSG
155    and *ERR.  */
156 
157 extern int
158 simple_object_internal_read (int descriptor, off_t offset,
159 			     unsigned char *buffer, size_t size,
160 			     const char **errmsg, int *err);
161 
162 /* Write SIZE bytes from BUFFER to DESCRIPTOR at file offset OFFSET.
163    Return non-zero on success.  On failure return 0 and set *ERRMSG
164    and *ERR.  */
165 
166 extern int
167 simple_object_internal_write (int descriptor, off_t offset,
168 			      const unsigned char *buffer, size_t size,
169 			      const char **errmsg, int *err);
170 
171 /* Define ulong_type as an unsigned 64-bit type if available.
172    Otherwise just make it unsigned long.  */
173 
174 #ifdef UNSIGNED_64BIT_TYPE
175 __extension__ typedef UNSIGNED_64BIT_TYPE ulong_type;
176 #else
177 typedef unsigned long ulong_type;
178 #endif
179 
180 /* Fetch a big-endian 16-bit value.  */
181 
182 static inline unsigned short
183 simple_object_fetch_big_16 (const unsigned char *buf)
184 {
185   return ((unsigned short) buf[0] << 8) | (unsigned short) buf[1];
186 }
187 
188 /* Fetch a little-endian 16-bit value.  */
189 
190 static inline unsigned short
191 simple_object_fetch_little_16 (const unsigned char *buf)
192 {
193   return ((unsigned short) buf[1] << 8) | (unsigned short) buf[0];
194 }
195 
196 /* Fetch a big-endian 32-bit value.  */
197 
198 static inline unsigned int
199 simple_object_fetch_big_32 (const unsigned char *buf)
200 {
201   return (((unsigned int) buf[0] << 24)
202 	  | ((unsigned int) buf[1] << 16)
203 	  | ((unsigned int) buf[2] << 8)
204 	  | (unsigned int) buf[3]);
205 }
206 
207 /* Fetch a little-endian 32-bit value.  */
208 
209 static inline unsigned int
210 simple_object_fetch_little_32 (const unsigned char *buf)
211 {
212   return (((unsigned int) buf[3] << 24)
213 	  | ((unsigned int) buf[2] << 16)
214 	  | ((unsigned int) buf[1] << 8)
215 	  | (unsigned int) buf[0]);
216 }
217 
218 /* Fetch a big-endian 32-bit value as a ulong_type.  */
219 
220 static inline ulong_type
221 simple_object_fetch_big_32_ulong (const unsigned char *buf)
222 {
223   return (ulong_type) simple_object_fetch_big_32 (buf);
224 }
225 
226 /* Fetch a little-endian 32-bit value as a ulong_type.  */
227 
228 static inline ulong_type
229 simple_object_fetch_little_32_ulong (const unsigned char *buf)
230 {
231   return (ulong_type) simple_object_fetch_little_32 (buf);
232 }
233 
234 #ifdef UNSIGNED_64BIT_TYPE
235 
236 /* Fetch a big-endian 64-bit value.  */
237 
238 static inline ulong_type
239 simple_object_fetch_big_64 (const unsigned char *buf)
240 {
241   return (((ulong_type) buf[0] << 56)
242 	  | ((ulong_type) buf[1] << 48)
243 	  | ((ulong_type) buf[2] << 40)
244 	  | ((ulong_type) buf[3] << 32)
245 	  | ((ulong_type) buf[4] << 24)
246 	  | ((ulong_type) buf[5] << 16)
247 	  | ((ulong_type) buf[6] << 8)
248 	  | (ulong_type) buf[7]);
249 }
250 
251 /* Fetch a little-endian 64-bit value.  */
252 
253 static inline ulong_type
254 simple_object_fetch_little_64 (const unsigned char *buf)
255 {
256   return (((ulong_type) buf[7] << 56)
257 	  | ((ulong_type) buf[6] << 48)
258 	  | ((ulong_type) buf[5] << 40)
259 	  | ((ulong_type) buf[4] << 32)
260 	  | ((ulong_type) buf[3] << 24)
261 	  | ((ulong_type) buf[2] << 16)
262 	  | ((ulong_type) buf[1] << 8)
263 	  | (ulong_type) buf[0]);
264 }
265 
266 #endif
267 
268 /* Store a big-endian 16-bit value.  */
269 
270 static inline void
271 simple_object_set_big_16 (unsigned char *buf, unsigned short val)
272 {
273   buf[0] = (val >> 8) & 0xff;
274   buf[1] = val & 0xff;
275 }
276 
277 /* Store a little-endian 16-bit value.  */
278 
279 static inline void
280 simple_object_set_little_16 (unsigned char *buf, unsigned short val)
281 {
282   buf[1] = (val >> 8) & 0xff;
283   buf[0] = val & 0xff;
284 }
285 
286 /* Store a big-endian 32-bit value.  */
287 
288 static inline void
289 simple_object_set_big_32 (unsigned char *buf, unsigned int val)
290 {
291   buf[0] = (val >> 24) & 0xff;
292   buf[1] = (val >> 16) & 0xff;
293   buf[2] = (val >> 8) & 0xff;
294   buf[3] = val & 0xff;
295 }
296 
297 /* Store a little-endian 32-bit value.  */
298 
299 static inline void
300 simple_object_set_little_32 (unsigned char *buf, unsigned int val)
301 {
302   buf[3] = (val >> 24) & 0xff;
303   buf[2] = (val >> 16) & 0xff;
304   buf[1] = (val >> 8) & 0xff;
305   buf[0] = val & 0xff;
306 }
307 
308 /* Store a big-endian 32-bit value coming in as a ulong_type.  */
309 
310 static inline void
311 simple_object_set_big_32_ulong (unsigned char *buf, ulong_type val)
312 {
313   simple_object_set_big_32 (buf, val);
314 }
315 
316 /* Store a little-endian 32-bit value coming in as a ulong_type.  */
317 
318 static inline void
319 simple_object_set_little_32_ulong (unsigned char *buf, ulong_type val)
320 {
321   simple_object_set_little_32 (buf, val);
322 }
323 
324 #ifdef UNSIGNED_64BIT_TYPE
325 
326 /* Store a big-endian 64-bit value.  */
327 
328 static inline void
329 simple_object_set_big_64 (unsigned char *buf, ulong_type val)
330 {
331   buf[0] = (val >> 56) & 0xff;
332   buf[1] = (val >> 48) & 0xff;
333   buf[2] = (val >> 40) & 0xff;
334   buf[3] = (val >> 32) & 0xff;
335   buf[4] = (val >> 24) & 0xff;
336   buf[5] = (val >> 16) & 0xff;
337   buf[6] = (val >> 8) & 0xff;
338   buf[7] = val & 0xff;
339 }
340 
341 /* Store a little-endian 64-bit value.  */
342 
343 static inline void
344 simple_object_set_little_64 (unsigned char *buf, ulong_type val)
345 {
346   buf[7] = (val >> 56) & 0xff;
347   buf[6] = (val >> 48) & 0xff;
348   buf[5] = (val >> 40) & 0xff;
349   buf[4] = (val >> 32) & 0xff;
350   buf[3] = (val >> 24) & 0xff;
351   buf[2] = (val >> 16) & 0xff;
352   buf[1] = (val >> 8) & 0xff;
353   buf[0] = val & 0xff;
354 }
355 
356 #endif
357