1/* simple-object-common.h -- common structs for object file manipulation.
2   Copyright (C) 2010-2022 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  /* 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
154extern const struct simple_object_functions simple_object_coff_functions;
155extern const struct simple_object_functions simple_object_elf_functions;
156extern const struct simple_object_functions simple_object_mach_o_functions;
157extern 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
163extern int
164simple_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
172extern int
173simple_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
183typedef unsigned long ulong_type;
184#endif
185
186/* Fetch a big-endian 16-bit value.  */
187
188static inline unsigned short
189simple_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
196static inline unsigned short
197simple_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
204static inline unsigned int
205simple_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
215static inline unsigned int
216simple_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
226static inline ulong_type
227simple_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
234static inline ulong_type
235simple_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
244static inline ulong_type
245simple_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
259static inline ulong_type
260simple_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
276static inline void
277simple_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
285static inline void
286simple_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
294static inline void
295simple_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
305static inline void
306simple_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
316static inline void
317simple_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
324static inline void
325simple_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
334static inline void
335simple_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
349static inline void
350simple_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
363