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a6be0538 | 1 | /* BFD back-end for WebAssembly modules. |
219d1afa | 2 | Copyright (C) 2017-2018 Free Software Foundation, Inc. |
a6be0538 PC |
3 | |
4 | Based on srec.c, mmo.c, and binary.c | |
5 | ||
6 | This file is part of BFD, the Binary File Descriptor library. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 3 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | MA 02110-1301, USA. */ | |
22 | ||
23 | /* The WebAssembly module format is a simple object file format | |
24 | including up to 11 numbered sections, plus any number of named | |
25 | "custom" sections. It is described at: | |
26 | https://github.com/WebAssembly/design/blob/master/BinaryEncoding.md. */ | |
27 | ||
28 | #include "sysdep.h" | |
29 | #include "alloca-conf.h" | |
30 | #include "bfd.h" | |
31 | #include "sysdep.h" | |
32 | #include <limits.h> | |
33 | #include "bfd_stdint.h" | |
34 | #include "libiberty.h" | |
35 | #include "libbfd.h" | |
36 | #include "wasm-module.h" | |
37 | ||
38 | typedef struct | |
39 | { | |
40 | asymbol * symbols; | |
41 | bfd_size_type symcount; | |
42 | } tdata_type; | |
43 | ||
44 | static const char * const wasm_numbered_sections[] = | |
45 | { | |
46 | NULL, /* Custom section, different layout. */ | |
47 | WASM_SECTION ( 1, "type"), | |
48 | WASM_SECTION ( 2, "import"), | |
49 | WASM_SECTION ( 3, "function"), | |
50 | WASM_SECTION ( 4, "table"), | |
51 | WASM_SECTION ( 5, "memory"), | |
52 | WASM_SECTION ( 6, "global"), | |
53 | WASM_SECTION ( 7, "export"), | |
54 | WASM_SECTION ( 8, "start"), | |
55 | WASM_SECTION ( 9, "element"), | |
56 | WASM_SECTION (10, "code"), | |
57 | WASM_SECTION (11, "data"), | |
58 | }; | |
59 | ||
60 | #define WASM_NUMBERED_SECTIONS ARRAY_SIZE (wasm_numbered_sections) | |
61 | ||
62 | /* Resolve SECTION_CODE to a section name if there is one, NULL | |
63 | otherwise. */ | |
64 | ||
65 | static const char * | |
66 | wasm_section_code_to_name (bfd_byte section_code) | |
67 | { | |
68 | if (section_code < WASM_NUMBERED_SECTIONS) | |
69 | return wasm_numbered_sections[section_code]; | |
70 | ||
71 | return NULL; | |
72 | } | |
73 | ||
74 | /* Translate section name NAME to a section code, or 0 if it's a | |
75 | custom name. */ | |
76 | ||
77 | static unsigned int | |
78 | wasm_section_name_to_code (const char *name) | |
79 | { | |
80 | unsigned i; | |
81 | ||
82 | for (i = 1; i < WASM_NUMBERED_SECTIONS; i++) | |
83 | if (strcmp (name, wasm_numbered_sections[i]) == 0) | |
84 | return i; | |
85 | ||
86 | return 0; | |
87 | } | |
88 | ||
89 | /* WebAssembly LEB128 integers are sufficiently like DWARF LEB128 | |
90 | integers that we use _bfd_safe_read_leb128, but there are two | |
91 | points of difference: | |
92 | ||
93 | - WebAssembly requires a 32-bit value to be encoded in at most 5 | |
94 | bytes, etc. | |
95 | - _bfd_safe_read_leb128 accepts incomplete LEB128 encodings at the | |
96 | end of the buffer, while these are invalid in WebAssembly. | |
97 | ||
98 | Those differences mean that we will accept some files that are | |
99 | invalid WebAssembly. */ | |
100 | ||
101 | /* Read an LEB128-encoded integer from ABFD's I/O stream, reading one | |
102 | byte at a time. Set ERROR_RETURN if no complete integer could be | |
103 | read, LENGTH_RETURN to the number of bytes read (including bytes in | |
104 | incomplete numbers). SIGN means interpret the number as SLEB128. */ | |
105 | ||
106 | static bfd_vma | |
07d6d2b8 AM |
107 | wasm_read_leb128 (bfd * abfd, |
108 | bfd_boolean * error_return, | |
109 | unsigned int * length_return, | |
110 | bfd_boolean sign) | |
a6be0538 PC |
111 | { |
112 | bfd_vma result = 0; | |
113 | unsigned int num_read = 0; | |
114 | unsigned int shift = 0; | |
115 | unsigned char byte = 0; | |
116 | bfd_boolean success = FALSE; | |
117 | ||
118 | while (bfd_bread (&byte, 1, abfd) == 1) | |
119 | { | |
120 | num_read++; | |
121 | ||
122 | result |= ((bfd_vma) (byte & 0x7f)) << shift; | |
123 | ||
124 | shift += 7; | |
125 | if ((byte & 0x80) == 0) | |
07d6d2b8 AM |
126 | { |
127 | success = TRUE; | |
128 | break; | |
129 | } | |
a6be0538 PC |
130 | } |
131 | ||
132 | if (length_return != NULL) | |
133 | *length_return = num_read; | |
134 | if (error_return != NULL) | |
135 | *error_return = ! success; | |
136 | ||
137 | if (sign && (shift < 8 * sizeof (result)) && (byte & 0x40)) | |
138 | result |= -((bfd_vma) 1 << shift); | |
139 | ||
140 | return result; | |
141 | } | |
142 | ||
143 | /* Encode an integer V as LEB128 and write it to ABFD, return TRUE on | |
144 | success. */ | |
145 | ||
146 | static bfd_boolean | |
147 | wasm_write_uleb128 (bfd *abfd, bfd_vma v) | |
148 | { | |
149 | do | |
150 | { | |
151 | bfd_byte c = v & 0x7f; | |
152 | v >>= 7; | |
153 | ||
154 | if (v) | |
07d6d2b8 | 155 | c |= 0x80; |
a6be0538 PC |
156 | |
157 | if (bfd_bwrite (&c, 1, abfd) != 1) | |
07d6d2b8 | 158 | return FALSE; |
a6be0538 PC |
159 | } |
160 | while (v); | |
161 | ||
162 | return TRUE; | |
163 | } | |
164 | ||
165 | /* Read the LEB128 integer at P, saving it to X; at end of buffer, | |
166 | jump to error_return. */ | |
07d6d2b8 AM |
167 | #define READ_LEB128(x, p, end) \ |
168 | do \ | |
169 | { \ | |
170 | unsigned int length_read; \ | |
171 | (x) = _bfd_safe_read_leb128 (abfd, (p), &length_read, \ | |
172 | FALSE, (end)); \ | |
173 | (p) += length_read; \ | |
174 | if (length_read == 0) \ | |
175 | goto error_return; \ | |
176 | } \ | |
a6be0538 PC |
177 | while (0) |
178 | ||
179 | /* Verify the magic number at the beginning of a WebAssembly module | |
180 | ABFD, setting ERRORPTR if there's a mismatch. */ | |
181 | ||
182 | static bfd_boolean | |
183 | wasm_read_magic (bfd *abfd, bfd_boolean *errorptr) | |
184 | { | |
185 | bfd_byte magic_const[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
186 | bfd_byte magic[SIZEOF_WASM_MAGIC]; | |
187 | ||
188 | if (bfd_bread (magic, sizeof (magic), abfd) == sizeof (magic) | |
189 | && memcmp (magic, magic_const, sizeof (magic)) == 0) | |
190 | return TRUE; | |
191 | ||
192 | *errorptr = TRUE; | |
193 | return FALSE; | |
194 | } | |
195 | ||
196 | /* Read the version number from ABFD, returning TRUE if it's a supported | |
197 | version. Set ERRORPTR otherwise. */ | |
198 | ||
199 | static bfd_boolean | |
200 | wasm_read_version (bfd *abfd, bfd_boolean *errorptr) | |
201 | { | |
202 | bfd_byte vers_const[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
203 | bfd_byte vers[SIZEOF_WASM_VERSION]; | |
204 | ||
205 | if (bfd_bread (vers, sizeof (vers), abfd) == sizeof (vers) | |
206 | /* Don't attempt to parse newer versions, which are likely to | |
207 | require code changes. */ | |
208 | && memcmp (vers, vers_const, sizeof (vers)) == 0) | |
209 | return TRUE; | |
210 | ||
211 | *errorptr = TRUE; | |
212 | return FALSE; | |
213 | } | |
214 | ||
215 | /* Read the WebAssembly header (magic number plus version number) from | |
216 | ABFD, setting ERRORPTR to TRUE if there is a mismatch. */ | |
217 | ||
218 | static bfd_boolean | |
219 | wasm_read_header (bfd *abfd, bfd_boolean *errorptr) | |
220 | { | |
221 | if (! wasm_read_magic (abfd, errorptr)) | |
222 | return FALSE; | |
223 | ||
224 | if (! wasm_read_version (abfd, errorptr)) | |
225 | return FALSE; | |
226 | ||
227 | return TRUE; | |
228 | } | |
229 | ||
230 | /* Scan the "function" subsection of the "name" section ASECT in the | |
231 | wasm module ABFD. Create symbols. Return TRUE on success. */ | |
232 | ||
233 | static bfd_boolean | |
234 | wasm_scan_name_function_section (bfd *abfd, sec_ptr asect) | |
235 | { | |
236 | bfd_byte *p; | |
237 | bfd_byte *end; | |
238 | bfd_vma payload_size; | |
239 | bfd_vma symcount = 0; | |
240 | tdata_type *tdata = abfd->tdata.any; | |
241 | asymbol *symbols = NULL; | |
242 | sec_ptr space_function_index; | |
243 | ||
244 | if (! asect) | |
245 | return FALSE; | |
246 | ||
247 | if (strcmp (asect->name, WASM_NAME_SECTION) != 0) | |
248 | return FALSE; | |
249 | ||
250 | p = asect->contents; | |
251 | end = asect->contents + asect->size; | |
252 | ||
253 | if (! p) | |
254 | return FALSE; | |
255 | ||
256 | while (p < end) | |
257 | { | |
258 | bfd_byte subsection_code = *p++; | |
259 | if (subsection_code == WASM_FUNCTION_SUBSECTION) | |
07d6d2b8 | 260 | break; |
a6be0538 PC |
261 | |
262 | /* subsection_code is documented to be a varuint7, meaning that | |
07d6d2b8 AM |
263 | it has to be a single byte in the 0 - 127 range. If it isn't, |
264 | the spec must have changed underneath us, so give up. */ | |
a6be0538 | 265 | if (subsection_code & 0x80) |
07d6d2b8 | 266 | return FALSE; |
a6be0538 PC |
267 | |
268 | READ_LEB128 (payload_size, p, end); | |
269 | ||
270 | if (p > p + payload_size) | |
07d6d2b8 | 271 | return FALSE; |
a6be0538 PC |
272 | |
273 | p += payload_size; | |
274 | } | |
275 | ||
276 | if (p >= end) | |
277 | return FALSE; | |
278 | ||
279 | READ_LEB128 (payload_size, p, end); | |
280 | ||
281 | if (p > p + payload_size) | |
282 | return FALSE; | |
283 | ||
284 | if (p + payload_size > end) | |
285 | return FALSE; | |
286 | ||
287 | end = p + payload_size; | |
288 | ||
289 | READ_LEB128 (symcount, p, end); | |
290 | ||
291 | /* Sanity check: each symbol has at least two bytes. */ | |
292 | if (symcount > payload_size/2) | |
293 | return FALSE; | |
294 | ||
295 | tdata->symcount = symcount; | |
296 | ||
297 | space_function_index = bfd_make_section_with_flags | |
298 | (abfd, WASM_SECTION_FUNCTION_INDEX, SEC_READONLY | SEC_CODE); | |
299 | ||
300 | if (! space_function_index) | |
301 | space_function_index = bfd_get_section_by_name (abfd, WASM_SECTION_FUNCTION_INDEX); | |
302 | ||
303 | if (! space_function_index) | |
304 | return FALSE; | |
305 | ||
306 | symbols = bfd_zalloc (abfd, tdata->symcount * sizeof (asymbol)); | |
307 | if (! symbols) | |
308 | return FALSE; | |
309 | ||
310 | for (symcount = 0; p < end && symcount < tdata->symcount; symcount++) | |
311 | { | |
312 | bfd_vma index; | |
313 | bfd_vma len; | |
314 | char *name; | |
315 | asymbol *sym; | |
316 | ||
317 | READ_LEB128 (index, p, end); | |
318 | READ_LEB128 (len, p, end); | |
319 | ||
320 | if (p + len < p || p + len > end) | |
07d6d2b8 | 321 | goto error_return; |
a6be0538 PC |
322 | |
323 | name = bfd_zalloc (abfd, len + 1); | |
324 | if (! name) | |
07d6d2b8 | 325 | goto error_return; |
a6be0538 PC |
326 | |
327 | memcpy (name, p, len); | |
328 | p += len; | |
329 | ||
330 | sym = &symbols[symcount]; | |
331 | sym->the_bfd = abfd; | |
332 | sym->name = name; | |
333 | sym->value = index; | |
334 | sym->flags = BSF_GLOBAL | BSF_FUNCTION; | |
335 | sym->section = space_function_index; | |
336 | sym->udata.p = NULL; | |
337 | } | |
338 | ||
339 | if (symcount < tdata->symcount) | |
340 | goto error_return; | |
341 | ||
342 | tdata->symbols = symbols; | |
343 | abfd->symcount = symcount; | |
344 | ||
345 | return TRUE; | |
346 | ||
347 | error_return: | |
348 | while (symcount) | |
349 | bfd_release (abfd, (void *)symbols[--symcount].name); | |
350 | bfd_release (abfd, symbols); | |
351 | return FALSE; | |
352 | } | |
353 | ||
354 | /* Read a byte from ABFD and return it, or EOF for EOF or error. | |
355 | Set ERRORPTR on non-EOF error. */ | |
356 | ||
357 | static int | |
358 | wasm_read_byte (bfd *abfd, bfd_boolean *errorptr) | |
359 | { | |
360 | bfd_byte byte; | |
361 | ||
362 | if (bfd_bread (&byte, (bfd_size_type) 1, abfd) != 1) | |
363 | { | |
364 | if (bfd_get_error () != bfd_error_file_truncated) | |
07d6d2b8 | 365 | *errorptr = TRUE; |
a6be0538 PC |
366 | return EOF; |
367 | } | |
368 | ||
369 | return byte; | |
370 | } | |
371 | ||
372 | /* Scan the wasm module ABFD, creating sections and symbols. | |
373 | Return TRUE on success. */ | |
374 | ||
375 | static bfd_boolean | |
376 | wasm_scan (bfd *abfd) | |
377 | { | |
378 | bfd_boolean error = FALSE; | |
379 | /* Fake VMAs for now. Choose 0x80000000 as base to avoid clashes | |
380 | with actual data addresses. */ | |
381 | bfd_vma vma = 0x80000000; | |
382 | int section_code; | |
383 | unsigned int bytes_read; | |
384 | char *name = NULL; | |
385 | asection *bfdsec; | |
386 | ||
387 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
388 | goto error_return; | |
389 | ||
390 | if (! wasm_read_header (abfd, &error)) | |
391 | goto error_return; | |
392 | ||
393 | while ((section_code = wasm_read_byte (abfd, &error)) != EOF) | |
394 | { | |
395 | if (section_code != 0) | |
07d6d2b8 AM |
396 | { |
397 | const char *sname = wasm_section_code_to_name (section_code); | |
398 | ||
399 | if (! sname) | |
400 | goto error_return; | |
401 | ||
402 | name = strdup (sname); | |
403 | bfdsec = bfd_make_section_anyway_with_flags (abfd, name, SEC_HAS_CONTENTS); | |
404 | if (bfdsec == NULL) | |
405 | goto error_return; | |
406 | name = NULL; | |
407 | ||
408 | bfdsec->vma = vma; | |
409 | bfdsec->lma = vma; | |
410 | bfdsec->size = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
411 | if (error) | |
412 | goto error_return; | |
413 | bfdsec->filepos = bfd_tell (abfd); | |
414 | bfdsec->alignment_power = 0; | |
415 | } | |
a6be0538 | 416 | else |
07d6d2b8 AM |
417 | { |
418 | bfd_vma payload_len; | |
419 | file_ptr section_start; | |
420 | bfd_vma namelen; | |
421 | char *prefix = WASM_SECTION_PREFIX; | |
422 | char *p; | |
423 | int ret; | |
424 | ||
425 | payload_len = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
426 | if (error) | |
427 | goto error_return; | |
428 | section_start = bfd_tell (abfd); | |
429 | namelen = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
430 | if (error || namelen > payload_len) | |
431 | goto error_return; | |
432 | name = bfd_zmalloc (namelen + strlen (prefix) + 1); | |
433 | if (! name) | |
434 | goto error_return; | |
435 | p = name; | |
436 | ret = sprintf (p, "%s", prefix); | |
437 | if (ret < 0 || (bfd_vma) ret != strlen (prefix)) | |
438 | goto error_return; | |
439 | p += ret; | |
440 | if (bfd_bread (p, namelen, abfd) != namelen) | |
a6be0538 PC |
441 | goto error_return; |
442 | ||
07d6d2b8 AM |
443 | bfdsec = bfd_make_section_anyway_with_flags (abfd, name, SEC_HAS_CONTENTS); |
444 | if (bfdsec == NULL) | |
445 | goto error_return; | |
446 | name = NULL; | |
a6be0538 | 447 | |
07d6d2b8 AM |
448 | bfdsec->vma = vma; |
449 | bfdsec->lma = vma; | |
450 | bfdsec->filepos = bfd_tell (abfd); | |
451 | bfdsec->size = section_start + payload_len - bfdsec->filepos; | |
452 | bfdsec->alignment_power = 0; | |
453 | } | |
a6be0538 PC |
454 | |
455 | if (bfdsec->size != 0) | |
07d6d2b8 AM |
456 | { |
457 | bfdsec->contents = bfd_zalloc (abfd, bfdsec->size); | |
458 | if (! bfdsec->contents) | |
459 | goto error_return; | |
a6be0538 | 460 | |
07d6d2b8 | 461 | if (bfd_bread (bfdsec->contents, bfdsec->size, abfd) != bfdsec->size) |
a6be0538 | 462 | goto error_return; |
07d6d2b8 | 463 | } |
a6be0538 PC |
464 | |
465 | vma += bfdsec->size; | |
466 | } | |
467 | ||
468 | /* Make sure we're at actual EOF. There's no indication in the | |
469 | WebAssembly format of how long the file is supposed to be. */ | |
470 | if (error) | |
471 | goto error_return; | |
472 | ||
473 | return TRUE; | |
474 | ||
475 | error_return: | |
476 | if (name) | |
477 | free (name); | |
478 | ||
479 | for (bfdsec = abfd->sections; bfdsec; bfdsec = bfdsec->next) | |
480 | free ((void *) bfdsec->name); | |
481 | ||
482 | return FALSE; | |
483 | } | |
484 | ||
485 | /* Put a numbered section ASECT of ABFD into the table of numbered | |
486 | sections pointed to by FSARG. */ | |
487 | ||
488 | static void | |
489 | wasm_register_section (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 | 490 | asection *asect, |
a6be0538 PC |
491 | void *fsarg) |
492 | { | |
493 | sec_ptr *numbered_sections = fsarg; | |
494 | int index = wasm_section_name_to_code (asect->name); | |
495 | ||
496 | if (index == 0) | |
497 | return; | |
498 | ||
499 | numbered_sections[index] = asect; | |
500 | } | |
501 | ||
502 | struct compute_section_arg | |
503 | { | |
504 | bfd_vma pos; | |
505 | bfd_boolean failed; | |
506 | }; | |
507 | ||
508 | /* Compute the file position of ABFD's section ASECT. FSARG is a | |
509 | pointer to the current file position. | |
510 | ||
511 | We allow section names of the form .wasm.id to encode the numbered | |
512 | section with ID id, if it exists; otherwise, a custom section with | |
513 | ID "id" is produced. Arbitrary section names are for sections that | |
514 | are assumed already to contain a section header; those are appended | |
515 | to the WebAssembly module verbatim. */ | |
516 | ||
517 | static void | |
518 | wasm_compute_custom_section_file_position (bfd *abfd, | |
519 | sec_ptr asect, | |
07d6d2b8 | 520 | void *fsarg) |
a6be0538 PC |
521 | { |
522 | struct compute_section_arg *fs = fsarg; | |
523 | int index; | |
524 | ||
525 | if (fs->failed) | |
526 | return; | |
527 | ||
528 | index = wasm_section_name_to_code (asect->name); | |
529 | ||
530 | if (index != 0) | |
531 | return; | |
532 | ||
533 | if (CONST_STRNEQ (asect->name, WASM_SECTION_PREFIX)) | |
534 | { | |
535 | const char *name = asect->name + strlen (WASM_SECTION_PREFIX); | |
536 | bfd_size_type payload_len = asect->size; | |
537 | bfd_size_type name_len = strlen (name); | |
538 | bfd_size_type nl = name_len; | |
539 | ||
540 | payload_len += name_len; | |
541 | ||
542 | do | |
07d6d2b8 AM |
543 | { |
544 | payload_len++; | |
545 | nl >>= 7; | |
546 | } | |
a6be0538 PC |
547 | while (nl); |
548 | ||
549 | bfd_seek (abfd, fs->pos, SEEK_SET); | |
550 | if (! wasm_write_uleb128 (abfd, 0) | |
07d6d2b8 AM |
551 | || ! wasm_write_uleb128 (abfd, payload_len) |
552 | || ! wasm_write_uleb128 (abfd, name_len) | |
553 | || bfd_bwrite (name, name_len, abfd) != name_len) | |
554 | goto error_return; | |
a6be0538 PC |
555 | fs->pos = asect->filepos = bfd_tell (abfd); |
556 | } | |
557 | else | |
558 | { | |
559 | asect->filepos = fs->pos; | |
560 | } | |
561 | ||
562 | ||
563 | fs->pos += asect->size; | |
564 | return; | |
565 | ||
566 | error_return: | |
567 | fs->failed = TRUE; | |
568 | } | |
569 | ||
570 | /* Compute the file positions for the sections of ABFD. Currently, | |
571 | this writes all numbered sections first, in order, then all custom | |
572 | sections, in section order. | |
573 | ||
574 | The spec says that the numbered sections must appear in order of | |
575 | their ids, but custom sections can appear in any position and any | |
576 | order, and more than once. FIXME: support that. */ | |
577 | ||
578 | static bfd_boolean | |
579 | wasm_compute_section_file_positions (bfd *abfd) | |
580 | { | |
581 | bfd_byte magic[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
582 | bfd_byte vers[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
583 | sec_ptr numbered_sections[WASM_NUMBERED_SECTIONS]; | |
584 | struct compute_section_arg fs; | |
585 | unsigned int i; | |
586 | ||
587 | bfd_seek (abfd, (bfd_vma) 0, SEEK_SET); | |
588 | ||
589 | if (bfd_bwrite (magic, sizeof (magic), abfd) != (sizeof magic) | |
590 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
591 | return FALSE; | |
592 | ||
593 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
594 | numbered_sections[i] = NULL; | |
595 | ||
596 | bfd_map_over_sections (abfd, wasm_register_section, numbered_sections); | |
597 | ||
598 | fs.pos = bfd_tell (abfd); | |
599 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
600 | { | |
601 | sec_ptr sec = numbered_sections[i]; | |
602 | bfd_size_type size; | |
603 | ||
604 | if (! sec) | |
07d6d2b8 | 605 | continue; |
a6be0538 PC |
606 | size = sec->size; |
607 | if (bfd_seek (abfd, fs.pos, SEEK_SET) != 0) | |
07d6d2b8 | 608 | return FALSE; |
a6be0538 | 609 | if (! wasm_write_uleb128 (abfd, i) |
07d6d2b8 AM |
610 | || ! wasm_write_uleb128 (abfd, size)) |
611 | return FALSE; | |
a6be0538 PC |
612 | fs.pos = sec->filepos = bfd_tell (abfd); |
613 | fs.pos += size; | |
614 | } | |
615 | ||
616 | fs.failed = FALSE; | |
617 | ||
618 | bfd_map_over_sections (abfd, wasm_compute_custom_section_file_position, &fs); | |
619 | ||
620 | if (fs.failed) | |
621 | return FALSE; | |
622 | ||
623 | abfd->output_has_begun = TRUE; | |
624 | ||
625 | return TRUE; | |
626 | } | |
627 | ||
628 | static bfd_boolean | |
629 | wasm_set_section_contents (bfd *abfd, | |
07d6d2b8 AM |
630 | sec_ptr section, |
631 | const void *location, | |
632 | file_ptr offset, | |
633 | bfd_size_type count) | |
a6be0538 PC |
634 | { |
635 | if (count == 0) | |
636 | return TRUE; | |
637 | ||
638 | if (! abfd->output_has_begun | |
639 | && ! wasm_compute_section_file_positions (abfd)) | |
640 | return FALSE; | |
641 | ||
642 | if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 | |
643 | || bfd_bwrite (location, count, abfd) != count) | |
644 | return FALSE; | |
645 | ||
646 | return TRUE; | |
647 | } | |
648 | ||
649 | static bfd_boolean | |
650 | wasm_write_object_contents (bfd* abfd) | |
651 | { | |
652 | bfd_byte magic[] = WASM_MAGIC; | |
653 | bfd_byte vers[] = WASM_VERSION; | |
654 | ||
655 | if (bfd_seek (abfd, 0, SEEK_SET) != 0) | |
656 | return FALSE; | |
657 | ||
658 | if (bfd_bwrite (magic, sizeof (magic), abfd) != sizeof (magic) | |
659 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
660 | return FALSE; | |
661 | ||
662 | return TRUE; | |
663 | } | |
664 | ||
665 | static bfd_boolean | |
666 | wasm_mkobject (bfd *abfd) | |
667 | { | |
668 | tdata_type *tdata = (tdata_type *) bfd_alloc (abfd, sizeof (tdata_type)); | |
669 | ||
670 | if (! tdata) | |
671 | return FALSE; | |
672 | ||
673 | tdata->symbols = NULL; | |
674 | tdata->symcount = 0; | |
675 | ||
676 | abfd->tdata.any = tdata; | |
677 | ||
678 | return TRUE; | |
679 | } | |
680 | ||
681 | static long | |
682 | wasm_get_symtab_upper_bound (bfd *abfd) | |
683 | { | |
684 | tdata_type *tdata = abfd->tdata.any; | |
685 | ||
686 | return (tdata->symcount + 1) * (sizeof (asymbol *)); | |
687 | } | |
688 | ||
689 | static long | |
690 | wasm_canonicalize_symtab (bfd *abfd, asymbol **alocation) | |
691 | { | |
692 | tdata_type *tdata = abfd->tdata.any; | |
693 | size_t i; | |
694 | ||
695 | for (i = 0; i < tdata->symcount; i++) | |
696 | alocation[i] = &tdata->symbols[i]; | |
697 | alocation[i] = NULL; | |
698 | ||
699 | return tdata->symcount; | |
700 | } | |
701 | ||
702 | static asymbol * | |
703 | wasm_make_empty_symbol (bfd *abfd) | |
704 | { | |
705 | bfd_size_type amt = sizeof (asymbol); | |
706 | asymbol *new_symbol = (asymbol *) bfd_zalloc (abfd, amt); | |
707 | ||
708 | if (! new_symbol) | |
709 | return NULL; | |
710 | new_symbol->the_bfd = abfd; | |
711 | return new_symbol; | |
712 | } | |
713 | ||
714 | static void | |
715 | wasm_print_symbol (bfd *abfd, | |
07d6d2b8 AM |
716 | void * filep, |
717 | asymbol *symbol, | |
718 | bfd_print_symbol_type how) | |
a6be0538 PC |
719 | { |
720 | FILE *file = (FILE *) filep; | |
721 | ||
722 | switch (how) | |
723 | { | |
724 | case bfd_print_symbol_name: | |
725 | fprintf (file, "%s", symbol->name); | |
726 | break; | |
727 | ||
728 | default: | |
729 | bfd_print_symbol_vandf (abfd, filep, symbol); | |
730 | fprintf (file, " %-5s %s", symbol->section->name, symbol->name); | |
731 | } | |
732 | } | |
733 | ||
734 | static void | |
735 | wasm_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 AM |
736 | asymbol *symbol, |
737 | symbol_info *ret) | |
a6be0538 PC |
738 | { |
739 | bfd_symbol_info (symbol, ret); | |
740 | } | |
741 | ||
742 | /* Check whether ABFD is a WebAssembly module; if so, scan it. */ | |
743 | ||
744 | static const bfd_target * | |
745 | wasm_object_p (bfd *abfd) | |
746 | { | |
747 | bfd_boolean error; | |
748 | ||
749 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
750 | return NULL; | |
751 | ||
752 | if (! wasm_read_header (abfd, &error)) | |
753 | { | |
754 | bfd_set_error (bfd_error_wrong_format); | |
755 | return NULL; | |
756 | } | |
757 | ||
758 | if (! wasm_mkobject (abfd) || ! wasm_scan (abfd)) | |
759 | return NULL; | |
760 | ||
761 | if (! bfd_default_set_arch_mach (abfd, bfd_arch_wasm32, 0)) | |
762 | return NULL; | |
763 | ||
764 | if (wasm_scan_name_function_section (abfd, bfd_get_section_by_name (abfd, WASM_NAME_SECTION))) | |
765 | abfd->flags |= HAS_SYMS; | |
766 | ||
767 | return abfd->xvec; | |
768 | } | |
769 | ||
770 | /* BFD_JUMP_TABLE_WRITE */ | |
07d6d2b8 | 771 | #define wasm_set_arch_mach _bfd_generic_set_arch_mach |
a6be0538 PC |
772 | |
773 | /* BFD_JUMP_TABLE_SYMBOLS */ | |
07d6d2b8 AM |
774 | #define wasm_get_symbol_version_string _bfd_nosymbols_get_symbol_version_string |
775 | #define wasm_bfd_is_local_label_name bfd_generic_is_local_label_name | |
a6be0538 | 776 | #define wasm_bfd_is_target_special_symbol ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false) |
07d6d2b8 AM |
777 | #define wasm_get_lineno _bfd_nosymbols_get_lineno |
778 | #define wasm_find_nearest_line _bfd_nosymbols_find_nearest_line | |
779 | #define wasm_find_line _bfd_nosymbols_find_line | |
780 | #define wasm_find_inliner_info _bfd_nosymbols_find_inliner_info | |
781 | #define wasm_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol | |
782 | #define wasm_read_minisymbols _bfd_generic_read_minisymbols | |
783 | #define wasm_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol | |
a6be0538 PC |
784 | |
785 | const bfd_target wasm_vec = | |
786 | { | |
07d6d2b8 | 787 | "wasm", /* Name. */ |
a6be0538 PC |
788 | bfd_target_unknown_flavour, |
789 | BFD_ENDIAN_LITTLE, | |
790 | BFD_ENDIAN_LITTLE, | |
791 | (HAS_SYMS | WP_TEXT), /* Object flags. */ | |
792 | (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS), /* Section flags. */ | |
07d6d2b8 AM |
793 | 0, /* Leading underscore. */ |
794 | ' ', /* AR_pad_char. */ | |
795 | 255, /* AR_max_namelen. */ | |
a6be0538 PC |
796 | 0, /* Match priority. */ |
797 | /* Routines to byte-swap various sized integers from the data sections. */ | |
798 | bfd_getl64, bfd_getl_signed_64, bfd_putl64, | |
799 | bfd_getl32, bfd_getl_signed_32, bfd_putl32, | |
800 | bfd_getl16, bfd_getl_signed_16, bfd_putl16, | |
801 | ||
802 | /* Routines to byte-swap various sized integers from the file headers. */ | |
803 | bfd_getl64, bfd_getl_signed_64, bfd_putl64, | |
804 | bfd_getl32, bfd_getl_signed_32, bfd_putl32, | |
805 | bfd_getl16, bfd_getl_signed_16, bfd_putl16, | |
806 | ||
807 | { | |
808 | _bfd_dummy_target, | |
809 | wasm_object_p, /* bfd_check_format. */ | |
810 | _bfd_dummy_target, | |
811 | _bfd_dummy_target, | |
812 | }, | |
813 | { | |
814 | bfd_false, | |
815 | wasm_mkobject, | |
816 | _bfd_generic_mkarchive, | |
817 | bfd_false, | |
818 | }, | |
819 | { /* bfd_write_contents. */ | |
820 | bfd_false, | |
821 | wasm_write_object_contents, | |
822 | _bfd_write_archive_contents, | |
823 | bfd_false, | |
824 | }, | |
825 | ||
826 | BFD_JUMP_TABLE_GENERIC (_bfd_generic), | |
827 | BFD_JUMP_TABLE_COPY (_bfd_generic), | |
828 | BFD_JUMP_TABLE_CORE (_bfd_nocore), | |
829 | BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), | |
830 | BFD_JUMP_TABLE_SYMBOLS (wasm), | |
831 | BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), | |
832 | BFD_JUMP_TABLE_WRITE (wasm), | |
833 | BFD_JUMP_TABLE_LINK (_bfd_nolink), | |
834 | BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), | |
835 | ||
836 | NULL, | |
837 | ||
838 | NULL, | |
839 | }; |