1/* simple-object-common.h -- common structs for object file manipulation.
2   Copyright (C) 2010 Free Software Foundation, Inc.
3
4This file is part of the libiberty library.
5Libiberty is free software; you can redistribute it and/or
6modify it under the terms of the GNU Library General Public
7License as published by the Free Software Foundation; either
8version 2 of the License, or (at your option) any later version.
9
10Libiberty is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13Library General Public License for more details.
14
15You should have received a copy of the GNU Library General Public
16License along with libiberty; see the file COPYING.LIB.  If not,
17write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
18Boston, MA 02110-1301, USA.  */
19
20/* Forward reference.  */
21struct simple_object_functions;
22
23/* An object file opened for reading.  */
24
25struct 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
39struct 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
49struct 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
65struct 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
82struct 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
100struct 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  /* Compare the private data for the attributes of two files.  If
127     they are the same, in the sense that they could be linked
128     together, return NULL.  Otherwise return an error message.  */
129  const char *(*attributes_compare) (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
148extern const struct simple_object_functions simple_object_coff_functions;
149extern const struct simple_object_functions simple_object_elf_functions;
150extern const struct simple_object_functions simple_object_mach_o_functions;
151
152/* Read SIZE bytes from DESCRIPTOR at file offset OFFSET into BUFFER.
153   Return non-zero on success.  On failure return 0 and set *ERRMSG
154   and *ERR.  */
155
156extern int
157simple_object_internal_read (int descriptor, off_t offset,
158			     unsigned char *buffer, size_t size,
159			     const char **errmsg, int *err);
160
161/* Write SIZE bytes from BUFFER to DESCRIPTOR at file offset OFFSET.
162   Return non-zero on success.  On failure return 0 and set *ERRMSG
163   and *ERR.  */
164
165extern int
166simple_object_internal_write (int descriptor, off_t offset,
167			      const unsigned char *buffer, size_t size,
168			      const char **errmsg, int *err);
169
170/* Define ulong_type as an unsigned 64-bit type if available.
171   Otherwise just make it unsigned long.  */
172
173#ifdef UNSIGNED_64BIT_TYPE
174__extension__ typedef UNSIGNED_64BIT_TYPE ulong_type;
175#else
176typedef unsigned long ulong_type;
177#endif
178
179/* Fetch a big-endian 16-bit value.  */
180
181static inline unsigned short
182simple_object_fetch_big_16 (const unsigned char *buf)
183{
184  return ((unsigned short) buf[0] << 8) | (unsigned short) buf[1];
185}
186
187/* Fetch a little-endian 16-bit value.  */
188
189static inline unsigned short
190simple_object_fetch_little_16 (const unsigned char *buf)
191{
192  return ((unsigned short) buf[1] << 8) | (unsigned short) buf[0];
193}
194
195/* Fetch a big-endian 32-bit value.  */
196
197static inline unsigned int
198simple_object_fetch_big_32 (const unsigned char *buf)
199{
200  return (((unsigned int) buf[0] << 24)
201	  | ((unsigned int) buf[1] << 16)
202	  | ((unsigned int) buf[2] << 8)
203	  | (unsigned int) buf[3]);
204}
205
206/* Fetch a little-endian 32-bit value.  */
207
208static inline unsigned int
209simple_object_fetch_little_32 (const unsigned char *buf)
210{
211  return (((unsigned int) buf[3] << 24)
212	  | ((unsigned int) buf[2] << 16)
213	  | ((unsigned int) buf[1] << 8)
214	  | (unsigned int) buf[0]);
215}
216
217/* Fetch a big-endian 32-bit value as a ulong_type.  */
218
219static inline ulong_type
220simple_object_fetch_big_32_ulong (const unsigned char *buf)
221{
222  return (ulong_type) simple_object_fetch_big_32 (buf);
223}
224
225/* Fetch a little-endian 32-bit value as a ulong_type.  */
226
227static inline ulong_type
228simple_object_fetch_little_32_ulong (const unsigned char *buf)
229{
230  return (ulong_type) simple_object_fetch_little_32 (buf);
231}
232
233#ifdef UNSIGNED_64BIT_TYPE
234
235/* Fetch a big-endian 64-bit value.  */
236
237static inline ulong_type
238simple_object_fetch_big_64 (const unsigned char *buf)
239{
240  return (((ulong_type) buf[0] << 56)
241	  | ((ulong_type) buf[1] << 48)
242	  | ((ulong_type) buf[2] << 40)
243	  | ((ulong_type) buf[3] << 32)
244	  | ((ulong_type) buf[4] << 24)
245	  | ((ulong_type) buf[5] << 16)
246	  | ((ulong_type) buf[6] << 8)
247	  | (ulong_type) buf[7]);
248}
249
250/* Fetch a little-endian 64-bit value.  */
251
252static inline ulong_type
253simple_object_fetch_little_64 (const unsigned char *buf)
254{
255  return (((ulong_type) buf[7] << 56)
256	  | ((ulong_type) buf[6] << 48)
257	  | ((ulong_type) buf[5] << 40)
258	  | ((ulong_type) buf[4] << 32)
259	  | ((ulong_type) buf[3] << 24)
260	  | ((ulong_type) buf[2] << 16)
261	  | ((ulong_type) buf[1] << 8)
262	  | (ulong_type) buf[0]);
263}
264
265#endif
266
267/* Store a big-endian 16-bit value.  */
268
269static inline void
270simple_object_set_big_16 (unsigned char *buf, unsigned short val)
271{
272  buf[0] = (val >> 8) & 0xff;
273  buf[1] = val & 0xff;
274}
275
276/* Store a little-endian 16-bit value.  */
277
278static inline void
279simple_object_set_little_16 (unsigned char *buf, unsigned short val)
280{
281  buf[1] = (val >> 8) & 0xff;
282  buf[0] = val & 0xff;
283}
284
285/* Store a big-endian 32-bit value.  */
286
287static inline void
288simple_object_set_big_32 (unsigned char *buf, unsigned int val)
289{
290  buf[0] = (val >> 24) & 0xff;
291  buf[1] = (val >> 16) & 0xff;
292  buf[2] = (val >> 8) & 0xff;
293  buf[3] = val & 0xff;
294}
295
296/* Store a little-endian 32-bit value.  */
297
298static inline void
299simple_object_set_little_32 (unsigned char *buf, unsigned int val)
300{
301  buf[3] = (val >> 24) & 0xff;
302  buf[2] = (val >> 16) & 0xff;
303  buf[1] = (val >> 8) & 0xff;
304  buf[0] = val & 0xff;
305}
306
307/* Store a big-endian 32-bit value coming in as a ulong_type.  */
308
309static inline void
310simple_object_set_big_32_ulong (unsigned char *buf, ulong_type val)
311{
312  simple_object_set_big_32 (buf, val);
313}
314
315/* Store a little-endian 32-bit value coming in as a ulong_type.  */
316
317static inline void
318simple_object_set_little_32_ulong (unsigned char *buf, ulong_type val)
319{
320  simple_object_set_little_32 (buf, val);
321}
322
323#ifdef UNSIGNED_64BIT_TYPE
324
325/* Store a big-endian 64-bit value.  */
326
327static inline void
328simple_object_set_big_64 (unsigned char *buf, ulong_type val)
329{
330  buf[0] = (val >> 56) & 0xff;
331  buf[1] = (val >> 48) & 0xff;
332  buf[2] = (val >> 40) & 0xff;
333  buf[3] = (val >> 32) & 0xff;
334  buf[4] = (val >> 24) & 0xff;
335  buf[5] = (val >> 16) & 0xff;
336  buf[6] = (val >> 8) & 0xff;
337  buf[7] = val & 0xff;
338}
339
340/* Store a little-endian 64-bit value.  */
341
342static inline void
343simple_object_set_little_64 (unsigned char *buf, ulong_type val)
344{
345  buf[7] = (val >> 56) & 0xff;
346  buf[6] = (val >> 48) & 0xff;
347  buf[5] = (val >> 40) & 0xff;
348  buf[4] = (val >> 32) & 0xff;
349  buf[3] = (val >> 24) & 0xff;
350  buf[2] = (val >> 16) & 0xff;
351  buf[1] = (val >> 8) & 0xff;
352  buf[0] = val & 0xff;
353}
354
355#endif
356