1 | /* simple-object-coff.c -- routines to manipulate COFF object files. |
2 | Copyright (C) 2010-2024 Free Software Foundation, Inc. |
3 | Written by Ian Lance Taylor, Google. |
4 | |
5 | This program is free software; you can redistribute it and/or modify it |
6 | under the terms of the GNU General Public License as published by the |
7 | Free Software Foundation; either version 2, or (at your option) any |
8 | later version. |
9 | |
10 | This program 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 |
13 | GNU General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU General Public License |
16 | along with this program; if not, write to the Free Software |
17 | Foundation, 51 Franklin Street - Fifth Floor, |
18 | Boston, MA 02110-1301, USA. */ |
19 | |
20 | #include "config.h" |
21 | #include "libiberty.h" |
22 | #include "simple-object.h" |
23 | |
24 | #include <errno.h> |
25 | #include <stddef.h> |
26 | |
27 | #ifdef HAVE_STDLIB_H |
28 | #include <stdlib.h> |
29 | #endif |
30 | |
31 | #ifdef HAVE_STDINT_H |
32 | #include <stdint.h> |
33 | #endif |
34 | |
35 | #ifdef HAVE_STRING_H |
36 | #include <string.h> |
37 | #endif |
38 | |
39 | #ifdef HAVE_INTTYPES_H |
40 | #include <inttypes.h> |
41 | #endif |
42 | |
43 | #include "simple-object-common.h" |
44 | |
45 | /* COFF structures and constants. */ |
46 | |
47 | /* COFF file header. */ |
48 | |
49 | struct external_filehdr |
50 | { |
51 | unsigned char f_magic[2]; /* magic number */ |
52 | unsigned char f_nscns[2]; /* number of sections */ |
53 | unsigned char f_timdat[4]; /* time & date stamp */ |
54 | unsigned char f_symptr[4]; /* file pointer to symtab */ |
55 | unsigned char f_nsyms[4]; /* number of symtab entries */ |
56 | unsigned char f_opthdr[2]; /* sizeof(optional hdr) */ |
57 | unsigned char f_flags[2]; /* flags */ |
58 | }; |
59 | |
60 | /* Bits for filehdr f_flags field. */ |
61 | |
62 | #define F_EXEC (0x0002) |
63 | #define IMAGE_FILE_SYSTEM (0x1000) |
64 | #define IMAGE_FILE_DLL (0x2000) |
65 | |
66 | /* COFF section header. */ |
67 | |
68 | struct external_scnhdr |
69 | { |
70 | unsigned char s_name[8]; /* section name */ |
71 | unsigned char s_paddr[4]; /* physical address, aliased s_nlib */ |
72 | unsigned char s_vaddr[4]; /* virtual address */ |
73 | unsigned char s_size[4]; /* section size */ |
74 | unsigned char s_scnptr[4]; /* file ptr to raw data for section */ |
75 | unsigned char s_relptr[4]; /* file ptr to relocation */ |
76 | unsigned char s_lnnoptr[4]; /* file ptr to line numbers */ |
77 | unsigned char s_nreloc[2]; /* number of relocation entries */ |
78 | unsigned char s_nlnno[2]; /* number of line number entries */ |
79 | unsigned char s_flags[4]; /* flags */ |
80 | }; |
81 | |
82 | /* The length of the s_name field in struct external_scnhdr. */ |
83 | |
84 | #define SCNNMLEN (8) |
85 | |
86 | /* Bits for scnhdr s_flags field. This includes some bits defined |
87 | only for PE. This may need to be moved into coff_magic. */ |
88 | |
89 | #define STYP_DATA (1 << 6) |
90 | #define IMAGE_SCN_MEM_DISCARDABLE (1 << 25) |
91 | #define IMAGE_SCN_MEM_SHARED (1 << 28) |
92 | #define IMAGE_SCN_MEM_READ (1 << 30) |
93 | |
94 | #define IMAGE_SCN_ALIGN_POWER_BIT_POS 20 |
95 | #define IMAGE_SCN_ALIGN_POWER_CONST(val) \ |
96 | (((val) + 1) << IMAGE_SCN_ALIGN_POWER_BIT_POS) |
97 | |
98 | /* COFF symbol table entry. */ |
99 | |
100 | #define E_SYMNMLEN 8 /* # characters in a symbol name */ |
101 | |
102 | struct external_syment |
103 | { |
104 | union |
105 | { |
106 | unsigned char e_name[E_SYMNMLEN]; |
107 | |
108 | struct |
109 | { |
110 | unsigned char e_zeroes[4]; |
111 | unsigned char e_offset[4]; |
112 | } e; |
113 | } e; |
114 | |
115 | unsigned char e_value[4]; |
116 | unsigned char e_scnum[2]; |
117 | unsigned char e_type[2]; |
118 | unsigned char e_sclass[1]; |
119 | unsigned char e_numaux[1]; |
120 | }; |
121 | |
122 | /* Length allowed for filename in aux sym format 4. */ |
123 | |
124 | #define E_FILNMLEN 18 |
125 | |
126 | /* Omits x_sym and other unused variants. */ |
127 | |
128 | union external_auxent |
129 | { |
130 | /* Aux sym format 4: file. */ |
131 | union |
132 | { |
133 | char x_fname[E_FILNMLEN]; |
134 | struct |
135 | { |
136 | unsigned char x_zeroes[4]; |
137 | unsigned char x_offset[4]; |
138 | } x_n; |
139 | } x_file; |
140 | /* Aux sym format 5: section. */ |
141 | struct |
142 | { |
143 | unsigned char x_scnlen[4]; /* section length */ |
144 | unsigned char x_nreloc[2]; /* # relocation entries */ |
145 | unsigned char x_nlinno[2]; /* # line numbers */ |
146 | unsigned char x_checksum[4]; /* section COMDAT checksum */ |
147 | unsigned char x_associated[2]; /* COMDAT assoc section index */ |
148 | unsigned char x_comdat[1]; /* COMDAT selection number */ |
149 | } x_scn; |
150 | }; |
151 | |
152 | /* Symbol-related constants. */ |
153 | |
154 | #define IMAGE_SYM_DEBUG (-2) |
155 | #define IMAGE_SYM_TYPE_NULL (0) |
156 | #define IMAGE_SYM_DTYPE_NULL (0) |
157 | #define IMAGE_SYM_CLASS_STATIC (3) |
158 | #define IMAGE_SYM_CLASS_FILE (103) |
159 | |
160 | #define IMAGE_SYM_TYPE \ |
161 | ((IMAGE_SYM_DTYPE_NULL << 4) | IMAGE_SYM_TYPE_NULL) |
162 | |
163 | /* Private data for an simple_object_read. */ |
164 | |
165 | struct simple_object_coff_read |
166 | { |
167 | /* Magic number. */ |
168 | unsigned short magic; |
169 | /* Whether the file is big-endian. */ |
170 | unsigned char is_big_endian; |
171 | /* Number of sections. */ |
172 | unsigned short nscns; |
173 | /* File offset of symbol table. */ |
174 | off_t symptr; |
175 | /* Number of symbol table entries. */ |
176 | unsigned int nsyms; |
177 | /* Flags. */ |
178 | unsigned short flags; |
179 | /* Offset of section headers in file. */ |
180 | off_t scnhdr_offset; |
181 | }; |
182 | |
183 | /* Private data for an simple_object_attributes. */ |
184 | |
185 | struct simple_object_coff_attributes |
186 | { |
187 | /* Magic number. */ |
188 | unsigned short magic; |
189 | /* Whether the file is big-endian. */ |
190 | unsigned char is_big_endian; |
191 | /* Flags. */ |
192 | unsigned short flags; |
193 | }; |
194 | |
195 | /* There is no magic number which indicates a COFF file as opposed to |
196 | any other sort of file. Instead, each COFF file starts with a |
197 | two-byte magic number which also indicates the type of the target. |
198 | This struct holds a magic number as well as characteristics of that |
199 | COFF format. */ |
200 | |
201 | struct coff_magic_struct |
202 | { |
203 | /* Magic number. */ |
204 | unsigned short magic; |
205 | /* Whether this magic number is for a big-endian file. */ |
206 | unsigned char is_big_endian; |
207 | /* Flag bits, in the f_flags fields, which indicates that this file |
208 | is not a relocatable object file. There is no flag which |
209 | specifically indicates a relocatable object file, it is only |
210 | implied by the absence of these flags. */ |
211 | unsigned short non_object_flags; |
212 | }; |
213 | |
214 | /* This is a list of the COFF magic numbers which we recognize, namely |
215 | the ones used on Windows. More can be added as needed. */ |
216 | |
217 | static const struct coff_magic_struct coff_magic[] = |
218 | { |
219 | /* i386. */ |
220 | { .magic: 0x14c, .is_big_endian: 0, F_EXEC | IMAGE_FILE_SYSTEM | IMAGE_FILE_DLL }, |
221 | /* x86_64. */ |
222 | { .magic: 0x8664, .is_big_endian: 0, F_EXEC | IMAGE_FILE_SYSTEM | IMAGE_FILE_DLL } |
223 | }; |
224 | |
225 | /* See if we have a COFF file. */ |
226 | |
227 | static void * |
228 | simple_object_coff_match (unsigned char [SIMPLE_OBJECT_MATCH_HEADER_LEN], |
229 | int descriptor, off_t offset, |
230 | const char *segment_name ATTRIBUTE_UNUSED, |
231 | const char **errmsg, int *err) |
232 | { |
233 | size_t c; |
234 | unsigned short magic_big; |
235 | unsigned short magic_little; |
236 | unsigned short magic; |
237 | size_t i; |
238 | int is_big_endian; |
239 | unsigned short (*fetch_16) (const unsigned char *); |
240 | unsigned int (*fetch_32) (const unsigned char *); |
241 | unsigned char hdrbuf[sizeof (struct external_filehdr)]; |
242 | unsigned short flags; |
243 | struct simple_object_coff_read *ocr; |
244 | |
245 | c = sizeof (coff_magic) / sizeof (coff_magic[0]); |
246 | magic_big = simple_object_fetch_big_16 (buf: header); |
247 | magic_little = simple_object_fetch_little_16 (buf: header); |
248 | for (i = 0; i < c; ++i) |
249 | { |
250 | if (coff_magic[i].is_big_endian |
251 | ? coff_magic[i].magic == magic_big |
252 | : coff_magic[i].magic == magic_little) |
253 | break; |
254 | } |
255 | if (i >= c) |
256 | { |
257 | *errmsg = NULL; |
258 | *err = 0; |
259 | return NULL; |
260 | } |
261 | is_big_endian = coff_magic[i].is_big_endian; |
262 | |
263 | magic = is_big_endian ? magic_big : magic_little; |
264 | fetch_16 = (is_big_endian |
265 | ? simple_object_fetch_big_16 |
266 | : simple_object_fetch_little_16); |
267 | fetch_32 = (is_big_endian |
268 | ? simple_object_fetch_big_32 |
269 | : simple_object_fetch_little_32); |
270 | |
271 | if (!simple_object_internal_read (descriptor, offset, buffer: hdrbuf, size: sizeof hdrbuf, |
272 | errmsg, err)) |
273 | return NULL; |
274 | |
275 | flags = fetch_16 (hdrbuf + offsetof (struct external_filehdr, f_flags)); |
276 | if ((flags & coff_magic[i].non_object_flags) != 0) |
277 | { |
278 | *errmsg = "not relocatable object file" ; |
279 | *err = 0; |
280 | return NULL; |
281 | } |
282 | |
283 | ocr = XNEW (struct simple_object_coff_read); |
284 | ocr->magic = magic; |
285 | ocr->is_big_endian = is_big_endian; |
286 | ocr->nscns = fetch_16 (hdrbuf + offsetof (struct external_filehdr, f_nscns)); |
287 | ocr->symptr = fetch_32 (hdrbuf |
288 | + offsetof (struct external_filehdr, f_symptr)); |
289 | ocr->nsyms = fetch_32 (hdrbuf + offsetof (struct external_filehdr, f_nsyms)); |
290 | ocr->flags = flags; |
291 | ocr->scnhdr_offset = (sizeof (struct external_filehdr) |
292 | + fetch_16 (hdrbuf + offsetof (struct external_filehdr, |
293 | f_opthdr))); |
294 | |
295 | return (void *) ocr; |
296 | } |
297 | |
298 | /* Read the string table in a COFF file. */ |
299 | |
300 | static char * |
301 | simple_object_coff_read_strtab (simple_object_read *sobj, size_t *strtab_size, |
302 | const char **errmsg, int *err) |
303 | { |
304 | struct simple_object_coff_read *ocr = |
305 | (struct simple_object_coff_read *) sobj->data; |
306 | off_t strtab_offset; |
307 | unsigned char strsizebuf[4]; |
308 | size_t strsize; |
309 | char *strtab; |
310 | |
311 | strtab_offset = sobj->offset + ocr->symptr |
312 | + ocr->nsyms * sizeof (struct external_syment); |
313 | if (!simple_object_internal_read (descriptor: sobj->descriptor, offset: strtab_offset, |
314 | buffer: strsizebuf, size: 4, errmsg, err)) |
315 | return NULL; |
316 | strsize = (ocr->is_big_endian |
317 | ? simple_object_fetch_big_32 (buf: strsizebuf) |
318 | : simple_object_fetch_little_32 (buf: strsizebuf)); |
319 | strtab = XNEWVEC (char, strsize); |
320 | if (!simple_object_internal_read (descriptor: sobj->descriptor, offset: strtab_offset, |
321 | buffer: (unsigned char *) strtab, size: strsize, errmsg, |
322 | err)) |
323 | { |
324 | XDELETEVEC (strtab); |
325 | return NULL; |
326 | } |
327 | *strtab_size = strsize; |
328 | return strtab; |
329 | } |
330 | |
331 | /* Find all sections in a COFF file. */ |
332 | |
333 | static const char * |
334 | simple_object_coff_find_sections (simple_object_read *sobj, |
335 | int (*pfn) (void *, const char *, |
336 | off_t offset, off_t length), |
337 | void *data, |
338 | int *err) |
339 | { |
340 | struct simple_object_coff_read *ocr = |
341 | (struct simple_object_coff_read *) sobj->data; |
342 | size_t scnhdr_size; |
343 | unsigned char *scnbuf; |
344 | const char *errmsg; |
345 | unsigned int (*fetch_32) (const unsigned char *); |
346 | unsigned int nscns; |
347 | char *strtab; |
348 | size_t strtab_size; |
349 | unsigned int i; |
350 | |
351 | scnhdr_size = sizeof (struct external_scnhdr); |
352 | scnbuf = XNEWVEC (unsigned char, scnhdr_size * ocr->nscns); |
353 | if (!simple_object_internal_read (descriptor: sobj->descriptor, |
354 | offset: sobj->offset + ocr->scnhdr_offset, |
355 | buffer: scnbuf, size: scnhdr_size * ocr->nscns, errmsg: &errmsg, |
356 | err)) |
357 | { |
358 | XDELETEVEC (scnbuf); |
359 | return errmsg; |
360 | } |
361 | |
362 | fetch_32 = (ocr->is_big_endian |
363 | ? simple_object_fetch_big_32 |
364 | : simple_object_fetch_little_32); |
365 | |
366 | nscns = ocr->nscns; |
367 | strtab = NULL; |
368 | strtab_size = 0; |
369 | for (i = 0; i < nscns; ++i) |
370 | { |
371 | unsigned char *scnhdr; |
372 | unsigned char *scnname; |
373 | char namebuf[SCNNMLEN + 1]; |
374 | char *name; |
375 | off_t scnptr; |
376 | unsigned int size; |
377 | |
378 | scnhdr = scnbuf + i * scnhdr_size; |
379 | scnname = scnhdr + offsetof (struct external_scnhdr, s_name); |
380 | memcpy (dest: namebuf, src: scnname, SCNNMLEN); |
381 | namebuf[SCNNMLEN] = '\0'; |
382 | name = &namebuf[0]; |
383 | if (namebuf[0] == '/') |
384 | { |
385 | size_t strindex; |
386 | char *end; |
387 | |
388 | strindex = strtol (nptr: namebuf + 1, endptr: &end, base: 10); |
389 | if (*end == '\0') |
390 | { |
391 | /* The real section name is found in the string |
392 | table. */ |
393 | if (strtab == NULL) |
394 | { |
395 | strtab = simple_object_coff_read_strtab (sobj, |
396 | strtab_size: &strtab_size, |
397 | errmsg: &errmsg, err); |
398 | if (strtab == NULL) |
399 | { |
400 | XDELETEVEC (scnbuf); |
401 | return errmsg; |
402 | } |
403 | } |
404 | |
405 | if (strindex < 4 || strindex >= strtab_size) |
406 | { |
407 | XDELETEVEC (strtab); |
408 | XDELETEVEC (scnbuf); |
409 | *err = 0; |
410 | return "section string index out of range" ; |
411 | } |
412 | |
413 | name = strtab + strindex; |
414 | } |
415 | } |
416 | |
417 | scnptr = fetch_32 (scnhdr + offsetof (struct external_scnhdr, s_scnptr)); |
418 | size = fetch_32 (scnhdr + offsetof (struct external_scnhdr, s_size)); |
419 | |
420 | if (!(*pfn) (data, name, scnptr, size)) |
421 | break; |
422 | } |
423 | |
424 | if (strtab != NULL) |
425 | XDELETEVEC (strtab); |
426 | XDELETEVEC (scnbuf); |
427 | |
428 | return NULL; |
429 | } |
430 | |
431 | /* Fetch the attributes for an simple_object_read. */ |
432 | |
433 | static void * |
434 | simple_object_coff_fetch_attributes (simple_object_read *sobj, |
435 | const char **errmsg ATTRIBUTE_UNUSED, |
436 | int *err ATTRIBUTE_UNUSED) |
437 | { |
438 | struct simple_object_coff_read *ocr = |
439 | (struct simple_object_coff_read *) sobj->data; |
440 | struct simple_object_coff_attributes *ret; |
441 | |
442 | ret = XNEW (struct simple_object_coff_attributes); |
443 | ret->magic = ocr->magic; |
444 | ret->is_big_endian = ocr->is_big_endian; |
445 | ret->flags = ocr->flags; |
446 | return ret; |
447 | } |
448 | |
449 | /* Release the private data for an simple_object_read. */ |
450 | |
451 | static void |
452 | simple_object_coff_release_read (void *data) |
453 | { |
454 | XDELETE (data); |
455 | } |
456 | |
457 | /* Compare two attributes structures. */ |
458 | |
459 | static const char * |
460 | simple_object_coff_attributes_merge (void *todata, void *fromdata, int *err) |
461 | { |
462 | struct simple_object_coff_attributes *to = |
463 | (struct simple_object_coff_attributes *) todata; |
464 | struct simple_object_coff_attributes *from = |
465 | (struct simple_object_coff_attributes *) fromdata; |
466 | |
467 | if (to->magic != from->magic || to->is_big_endian != from->is_big_endian) |
468 | { |
469 | *err = 0; |
470 | return "COFF object format mismatch" ; |
471 | } |
472 | return NULL; |
473 | } |
474 | |
475 | /* Release the private data for an attributes structure. */ |
476 | |
477 | static void |
478 | simple_object_coff_release_attributes (void *data) |
479 | { |
480 | XDELETE (data); |
481 | } |
482 | |
483 | /* Prepare to write out a file. */ |
484 | |
485 | static void * |
486 | simple_object_coff_start_write (void *attributes_data, |
487 | const char **errmsg ATTRIBUTE_UNUSED, |
488 | int *err ATTRIBUTE_UNUSED) |
489 | { |
490 | struct simple_object_coff_attributes *attrs = |
491 | (struct simple_object_coff_attributes *) attributes_data; |
492 | struct simple_object_coff_attributes *ret; |
493 | |
494 | /* We're just going to record the attributes, but we need to make a |
495 | copy because the user may delete them. */ |
496 | ret = XNEW (struct simple_object_coff_attributes); |
497 | *ret = *attrs; |
498 | return ret; |
499 | } |
500 | |
501 | /* Write out a COFF filehdr. */ |
502 | |
503 | static int |
504 | simple_object_coff_write_filehdr (simple_object_write *sobj, int descriptor, |
505 | unsigned int nscns, size_t symtab_offset, |
506 | unsigned int nsyms, const char **errmsg, |
507 | int *err) |
508 | { |
509 | struct simple_object_coff_attributes *attrs = |
510 | (struct simple_object_coff_attributes *) sobj->data; |
511 | unsigned char hdrbuf[sizeof (struct external_filehdr)]; |
512 | unsigned char *hdr; |
513 | void (*set_16) (unsigned char *, unsigned short); |
514 | void (*set_32) (unsigned char *, unsigned int); |
515 | |
516 | hdr = &hdrbuf[0]; |
517 | |
518 | set_16 = (attrs->is_big_endian |
519 | ? simple_object_set_big_16 |
520 | : simple_object_set_little_16); |
521 | set_32 = (attrs->is_big_endian |
522 | ? simple_object_set_big_32 |
523 | : simple_object_set_little_32); |
524 | |
525 | memset (s: hdr, c: 0, n: sizeof (struct external_filehdr)); |
526 | |
527 | set_16 (hdr + offsetof (struct external_filehdr, f_magic), attrs->magic); |
528 | set_16 (hdr + offsetof (struct external_filehdr, f_nscns), nscns); |
529 | /* f_timdat left as zero. */ |
530 | set_32 (hdr + offsetof (struct external_filehdr, f_symptr), symtab_offset); |
531 | set_32 (hdr + offsetof (struct external_filehdr, f_nsyms), nsyms); |
532 | /* f_opthdr left as zero. */ |
533 | set_16 (hdr + offsetof (struct external_filehdr, f_flags), attrs->flags); |
534 | |
535 | return simple_object_internal_write (descriptor, offset: 0, buffer: hdrbuf, |
536 | size: sizeof (struct external_filehdr), |
537 | errmsg, err); |
538 | } |
539 | |
540 | /* Write out a COFF section header. */ |
541 | |
542 | static int |
543 | simple_object_coff_write_scnhdr (simple_object_write *sobj, int descriptor, |
544 | const char *name, size_t *name_offset, |
545 | off_t scnhdr_offset, size_t scnsize, |
546 | off_t offset, unsigned int align, |
547 | const char **errmsg, int *err) |
548 | { |
549 | struct simple_object_coff_attributes *attrs = |
550 | (struct simple_object_coff_attributes *) sobj->data; |
551 | void (*set_32) (unsigned char *, unsigned int); |
552 | unsigned char hdrbuf[sizeof (struct external_scnhdr)]; |
553 | unsigned char *hdr; |
554 | size_t namelen; |
555 | unsigned int flags; |
556 | |
557 | set_32 = (attrs->is_big_endian |
558 | ? simple_object_set_big_32 |
559 | : simple_object_set_little_32); |
560 | |
561 | memset (s: hdrbuf, c: 0, n: sizeof hdrbuf); |
562 | hdr = &hdrbuf[0]; |
563 | |
564 | namelen = strlen (s: name); |
565 | if (namelen <= SCNNMLEN) |
566 | strncpy (dest: (char *) hdr + offsetof (struct external_scnhdr, s_name), src: name, |
567 | SCNNMLEN); |
568 | else |
569 | { |
570 | snprintf (s: (char *) hdr + offsetof (struct external_scnhdr, s_name), |
571 | SCNNMLEN, format: "/%lu" , (unsigned long) *name_offset); |
572 | *name_offset += namelen + 1; |
573 | } |
574 | |
575 | /* s_paddr left as zero. */ |
576 | /* s_vaddr left as zero. */ |
577 | set_32 (hdr + offsetof (struct external_scnhdr, s_size), scnsize); |
578 | set_32 (hdr + offsetof (struct external_scnhdr, s_scnptr), offset); |
579 | /* s_relptr left as zero. */ |
580 | /* s_lnnoptr left as zero. */ |
581 | /* s_nreloc left as zero. */ |
582 | /* s_nlnno left as zero. */ |
583 | flags = (STYP_DATA | IMAGE_SCN_MEM_DISCARDABLE | IMAGE_SCN_MEM_SHARED |
584 | | IMAGE_SCN_MEM_READ); |
585 | /* PE can represent alignment up to 13. */ |
586 | if (align > 13) |
587 | align = 13; |
588 | flags |= IMAGE_SCN_ALIGN_POWER_CONST(align); |
589 | set_32 (hdr + offsetof (struct external_scnhdr, s_flags), flags); |
590 | |
591 | return simple_object_internal_write (descriptor, offset: scnhdr_offset, buffer: hdrbuf, |
592 | size: sizeof (struct external_scnhdr), |
593 | errmsg, err); |
594 | } |
595 | |
596 | /* Write out a complete COFF file. */ |
597 | |
598 | static const char * |
599 | simple_object_coff_write_to_file (simple_object_write *sobj, int descriptor, |
600 | int *err) |
601 | { |
602 | struct simple_object_coff_attributes *attrs = |
603 | (struct simple_object_coff_attributes *) sobj->data; |
604 | unsigned int nscns, secnum; |
605 | simple_object_write_section *section; |
606 | off_t scnhdr_offset; |
607 | size_t symtab_offset; |
608 | off_t secsym_offset; |
609 | unsigned int nsyms; |
610 | size_t offset; |
611 | size_t name_offset; |
612 | const char *errmsg; |
613 | unsigned char strsizebuf[4]; |
614 | /* The interface doesn't give us access to the name of the input file |
615 | yet. We want to use its basename for the FILE symbol. This is |
616 | what 'gas' uses when told to assemble from stdin. */ |
617 | const char *source_filename = "fake" ; |
618 | size_t sflen; |
619 | union |
620 | { |
621 | struct external_syment sym; |
622 | union external_auxent aux; |
623 | } syms[2]; |
624 | void (*set_16) (unsigned char *, unsigned short); |
625 | void (*set_32) (unsigned char *, unsigned int); |
626 | |
627 | set_16 = (attrs->is_big_endian |
628 | ? simple_object_set_big_16 |
629 | : simple_object_set_little_16); |
630 | set_32 = (attrs->is_big_endian |
631 | ? simple_object_set_big_32 |
632 | : simple_object_set_little_32); |
633 | |
634 | nscns = 0; |
635 | for (section = sobj->sections; section != NULL; section = section->next) |
636 | ++nscns; |
637 | |
638 | scnhdr_offset = sizeof (struct external_filehdr); |
639 | offset = scnhdr_offset + nscns * sizeof (struct external_scnhdr); |
640 | name_offset = 4; |
641 | for (section = sobj->sections; section != NULL; section = section->next) |
642 | { |
643 | size_t mask; |
644 | size_t new_offset; |
645 | size_t scnsize; |
646 | struct simple_object_write_section_buffer *buffer; |
647 | |
648 | mask = (1U << section->align) - 1; |
649 | new_offset = offset & mask; |
650 | new_offset &= ~ mask; |
651 | while (new_offset > offset) |
652 | { |
653 | unsigned char zeroes[16]; |
654 | size_t write; |
655 | |
656 | memset (s: zeroes, c: 0, n: sizeof zeroes); |
657 | write = new_offset - offset; |
658 | if (write > sizeof zeroes) |
659 | write = sizeof zeroes; |
660 | if (!simple_object_internal_write (descriptor, offset, buffer: zeroes, size: write, |
661 | errmsg: &errmsg, err)) |
662 | return errmsg; |
663 | } |
664 | |
665 | scnsize = 0; |
666 | for (buffer = section->buffers; buffer != NULL; buffer = buffer->next) |
667 | { |
668 | if (!simple_object_internal_write (descriptor, offset: offset + scnsize, |
669 | buffer: ((const unsigned char *) |
670 | buffer->buffer), |
671 | size: buffer->size, errmsg: &errmsg, err)) |
672 | return errmsg; |
673 | scnsize += buffer->size; |
674 | } |
675 | |
676 | if (!simple_object_coff_write_scnhdr (sobj, descriptor, name: section->name, |
677 | name_offset: &name_offset, scnhdr_offset, |
678 | scnsize, offset, align: section->align, |
679 | errmsg: &errmsg, err)) |
680 | return errmsg; |
681 | |
682 | scnhdr_offset += sizeof (struct external_scnhdr); |
683 | offset += scnsize; |
684 | } |
685 | |
686 | /* Symbol table is always half-word aligned. */ |
687 | offset += (offset & 1); |
688 | /* There is a file symbol and a section symbol per section, |
689 | and each of these has a single auxiliary symbol following. */ |
690 | nsyms = 2 * (nscns + 1); |
691 | symtab_offset = offset; |
692 | /* Advance across space reserved for symbol table to locate |
693 | start of string table. */ |
694 | offset += nsyms * sizeof (struct external_syment); |
695 | |
696 | /* Write out file symbol. */ |
697 | memset (s: &syms[0], c: 0, n: sizeof (syms)); |
698 | strcpy (dest: (char *)&syms[0].sym.e.e_name[0], src: ".file" ); |
699 | set_16 (&syms[0].sym.e_scnum[0], IMAGE_SYM_DEBUG); |
700 | set_16 (&syms[0].sym.e_type[0], IMAGE_SYM_TYPE); |
701 | syms[0].sym.e_sclass[0] = IMAGE_SYM_CLASS_FILE; |
702 | syms[0].sym.e_numaux[0] = 1; |
703 | /* The name need not be nul-terminated if it fits into the x_fname field |
704 | directly, but must be if it has to be placed into the string table. */ |
705 | sflen = strlen (s: source_filename); |
706 | if (sflen <= E_FILNMLEN) |
707 | memcpy (dest: &syms[1].aux.x_file.x_fname[0], src: source_filename, n: sflen); |
708 | else |
709 | { |
710 | set_32 (&syms[1].aux.x_file.x_n.x_offset[0], name_offset); |
711 | if (!simple_object_internal_write (descriptor, offset: offset + name_offset, |
712 | buffer: ((const unsigned char *) |
713 | source_filename), |
714 | size: sflen + 1, errmsg: &errmsg, err)) |
715 | return errmsg; |
716 | name_offset += strlen (s: source_filename) + 1; |
717 | } |
718 | if (!simple_object_internal_write (descriptor, offset: symtab_offset, |
719 | buffer: (const unsigned char *) &syms[0], |
720 | size: sizeof (syms), errmsg: &errmsg, err)) |
721 | return errmsg; |
722 | |
723 | /* Write the string table length, followed by the strings and section |
724 | symbols in step with each other. */ |
725 | set_32 (strsizebuf, name_offset); |
726 | if (!simple_object_internal_write (descriptor, offset, buffer: strsizebuf, size: 4, |
727 | errmsg: &errmsg, err)) |
728 | return errmsg; |
729 | |
730 | name_offset = 4; |
731 | secsym_offset = symtab_offset + sizeof (syms); |
732 | memset (s: &syms[0], c: 0, n: sizeof (syms)); |
733 | set_16 (&syms[0].sym.e_type[0], IMAGE_SYM_TYPE); |
734 | syms[0].sym.e_sclass[0] = IMAGE_SYM_CLASS_STATIC; |
735 | syms[0].sym.e_numaux[0] = 1; |
736 | secnum = 1; |
737 | |
738 | for (section = sobj->sections; section != NULL; section = section->next) |
739 | { |
740 | size_t namelen; |
741 | size_t scnsize; |
742 | struct simple_object_write_section_buffer *buffer; |
743 | |
744 | namelen = strlen (s: section->name); |
745 | set_16 (&syms[0].sym.e_scnum[0], secnum++); |
746 | scnsize = 0; |
747 | for (buffer = section->buffers; buffer != NULL; buffer = buffer->next) |
748 | scnsize += buffer->size; |
749 | set_32 (&syms[1].aux.x_scn.x_scnlen[0], scnsize); |
750 | if (namelen > SCNNMLEN) |
751 | { |
752 | set_32 (&syms[0].sym.e.e.e_zeroes[0], 0); |
753 | set_32 (&syms[0].sym.e.e.e_offset[0], name_offset); |
754 | if (!simple_object_internal_write (descriptor, offset: offset + name_offset, |
755 | buffer: ((const unsigned char *) |
756 | section->name), |
757 | size: namelen + 1, errmsg: &errmsg, err)) |
758 | return errmsg; |
759 | name_offset += namelen + 1; |
760 | } |
761 | else |
762 | { |
763 | memcpy (dest: &syms[0].sym.e.e_name[0], src: section->name, |
764 | n: strlen (s: section->name)); |
765 | memset (s: &syms[0].sym.e.e_name[strlen (s: section->name)], c: 0, |
766 | E_SYMNMLEN - strlen (s: section->name)); |
767 | } |
768 | |
769 | if (!simple_object_internal_write (descriptor, offset: secsym_offset, |
770 | buffer: (const unsigned char *) &syms[0], |
771 | size: sizeof (syms), errmsg: &errmsg, err)) |
772 | return errmsg; |
773 | secsym_offset += sizeof (syms); |
774 | } |
775 | |
776 | if (!simple_object_coff_write_filehdr (sobj, descriptor, nscns, |
777 | symtab_offset, nsyms, errmsg: &errmsg, err)) |
778 | return errmsg; |
779 | |
780 | return NULL; |
781 | } |
782 | |
783 | /* Release the private data for an simple_object_write structure. */ |
784 | |
785 | static void |
786 | simple_object_coff_release_write (void *data) |
787 | { |
788 | XDELETE (data); |
789 | } |
790 | |
791 | /* The COFF functions. */ |
792 | |
793 | const struct simple_object_functions simple_object_coff_functions = |
794 | { |
795 | .match: simple_object_coff_match, |
796 | .find_sections: simple_object_coff_find_sections, |
797 | .fetch_attributes: simple_object_coff_fetch_attributes, |
798 | .release_read: simple_object_coff_release_read, |
799 | .attributes_merge: simple_object_coff_attributes_merge, |
800 | .release_attributes: simple_object_coff_release_attributes, |
801 | .start_write: simple_object_coff_start_write, |
802 | .write_to_file: simple_object_coff_write_to_file, |
803 | .release_write: simple_object_coff_release_write, |
804 | NULL |
805 | }; |
806 | |