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a6be0538 | 1 | /* BFD back-end for WebAssembly modules. |
82704155 | 2 | Copyright (C) 2017-2019 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" | |
a6be0538 | 31 | #include <limits.h> |
a6be0538 PC |
32 | #include "libiberty.h" |
33 | #include "libbfd.h" | |
34 | #include "wasm-module.h" | |
35 | ||
36 | typedef struct | |
37 | { | |
38 | asymbol * symbols; | |
39 | bfd_size_type symcount; | |
40 | } tdata_type; | |
41 | ||
42 | static const char * const wasm_numbered_sections[] = | |
43 | { | |
44 | NULL, /* Custom section, different layout. */ | |
45 | WASM_SECTION ( 1, "type"), | |
46 | WASM_SECTION ( 2, "import"), | |
47 | WASM_SECTION ( 3, "function"), | |
48 | WASM_SECTION ( 4, "table"), | |
49 | WASM_SECTION ( 5, "memory"), | |
50 | WASM_SECTION ( 6, "global"), | |
51 | WASM_SECTION ( 7, "export"), | |
52 | WASM_SECTION ( 8, "start"), | |
53 | WASM_SECTION ( 9, "element"), | |
54 | WASM_SECTION (10, "code"), | |
55 | WASM_SECTION (11, "data"), | |
56 | }; | |
57 | ||
58 | #define WASM_NUMBERED_SECTIONS ARRAY_SIZE (wasm_numbered_sections) | |
59 | ||
60 | /* Resolve SECTION_CODE to a section name if there is one, NULL | |
61 | otherwise. */ | |
62 | ||
63 | static const char * | |
64 | wasm_section_code_to_name (bfd_byte section_code) | |
65 | { | |
66 | if (section_code < WASM_NUMBERED_SECTIONS) | |
67 | return wasm_numbered_sections[section_code]; | |
68 | ||
69 | return NULL; | |
70 | } | |
71 | ||
72 | /* Translate section name NAME to a section code, or 0 if it's a | |
73 | custom name. */ | |
74 | ||
75 | static unsigned int | |
76 | wasm_section_name_to_code (const char *name) | |
77 | { | |
78 | unsigned i; | |
79 | ||
80 | for (i = 1; i < WASM_NUMBERED_SECTIONS; i++) | |
81 | if (strcmp (name, wasm_numbered_sections[i]) == 0) | |
82 | return i; | |
83 | ||
84 | return 0; | |
85 | } | |
86 | ||
87 | /* WebAssembly LEB128 integers are sufficiently like DWARF LEB128 | |
88 | integers that we use _bfd_safe_read_leb128, but there are two | |
89 | points of difference: | |
90 | ||
91 | - WebAssembly requires a 32-bit value to be encoded in at most 5 | |
92 | bytes, etc. | |
93 | - _bfd_safe_read_leb128 accepts incomplete LEB128 encodings at the | |
94 | end of the buffer, while these are invalid in WebAssembly. | |
95 | ||
96 | Those differences mean that we will accept some files that are | |
97 | invalid WebAssembly. */ | |
98 | ||
99 | /* Read an LEB128-encoded integer from ABFD's I/O stream, reading one | |
100 | byte at a time. Set ERROR_RETURN if no complete integer could be | |
101 | read, LENGTH_RETURN to the number of bytes read (including bytes in | |
102 | incomplete numbers). SIGN means interpret the number as SLEB128. */ | |
103 | ||
104 | static bfd_vma | |
07d6d2b8 AM |
105 | wasm_read_leb128 (bfd * abfd, |
106 | bfd_boolean * error_return, | |
107 | unsigned int * length_return, | |
108 | bfd_boolean sign) | |
a6be0538 PC |
109 | { |
110 | bfd_vma result = 0; | |
111 | unsigned int num_read = 0; | |
112 | unsigned int shift = 0; | |
113 | unsigned char byte = 0; | |
114 | bfd_boolean success = FALSE; | |
115 | ||
116 | while (bfd_bread (&byte, 1, abfd) == 1) | |
117 | { | |
118 | num_read++; | |
119 | ||
120 | result |= ((bfd_vma) (byte & 0x7f)) << shift; | |
121 | ||
122 | shift += 7; | |
123 | if ((byte & 0x80) == 0) | |
07d6d2b8 AM |
124 | { |
125 | success = TRUE; | |
126 | break; | |
127 | } | |
a6be0538 PC |
128 | } |
129 | ||
130 | if (length_return != NULL) | |
131 | *length_return = num_read; | |
132 | if (error_return != NULL) | |
133 | *error_return = ! success; | |
134 | ||
135 | if (sign && (shift < 8 * sizeof (result)) && (byte & 0x40)) | |
136 | result |= -((bfd_vma) 1 << shift); | |
137 | ||
138 | return result; | |
139 | } | |
140 | ||
141 | /* Encode an integer V as LEB128 and write it to ABFD, return TRUE on | |
142 | success. */ | |
143 | ||
144 | static bfd_boolean | |
145 | wasm_write_uleb128 (bfd *abfd, bfd_vma v) | |
146 | { | |
147 | do | |
148 | { | |
149 | bfd_byte c = v & 0x7f; | |
150 | v >>= 7; | |
151 | ||
152 | if (v) | |
07d6d2b8 | 153 | c |= 0x80; |
a6be0538 PC |
154 | |
155 | if (bfd_bwrite (&c, 1, abfd) != 1) | |
07d6d2b8 | 156 | return FALSE; |
a6be0538 PC |
157 | } |
158 | while (v); | |
159 | ||
160 | return TRUE; | |
161 | } | |
162 | ||
163 | /* Read the LEB128 integer at P, saving it to X; at end of buffer, | |
164 | jump to error_return. */ | |
07d6d2b8 AM |
165 | #define READ_LEB128(x, p, end) \ |
166 | do \ | |
167 | { \ | |
168 | unsigned int length_read; \ | |
169 | (x) = _bfd_safe_read_leb128 (abfd, (p), &length_read, \ | |
170 | FALSE, (end)); \ | |
171 | (p) += length_read; \ | |
172 | if (length_read == 0) \ | |
173 | goto error_return; \ | |
174 | } \ | |
a6be0538 PC |
175 | while (0) |
176 | ||
177 | /* Verify the magic number at the beginning of a WebAssembly module | |
178 | ABFD, setting ERRORPTR if there's a mismatch. */ | |
179 | ||
180 | static bfd_boolean | |
181 | wasm_read_magic (bfd *abfd, bfd_boolean *errorptr) | |
182 | { | |
183 | bfd_byte magic_const[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
184 | bfd_byte magic[SIZEOF_WASM_MAGIC]; | |
185 | ||
186 | if (bfd_bread (magic, sizeof (magic), abfd) == sizeof (magic) | |
187 | && memcmp (magic, magic_const, sizeof (magic)) == 0) | |
188 | return TRUE; | |
189 | ||
190 | *errorptr = TRUE; | |
191 | return FALSE; | |
192 | } | |
193 | ||
194 | /* Read the version number from ABFD, returning TRUE if it's a supported | |
195 | version. Set ERRORPTR otherwise. */ | |
196 | ||
197 | static bfd_boolean | |
198 | wasm_read_version (bfd *abfd, bfd_boolean *errorptr) | |
199 | { | |
200 | bfd_byte vers_const[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
201 | bfd_byte vers[SIZEOF_WASM_VERSION]; | |
202 | ||
203 | if (bfd_bread (vers, sizeof (vers), abfd) == sizeof (vers) | |
204 | /* Don't attempt to parse newer versions, which are likely to | |
205 | require code changes. */ | |
206 | && memcmp (vers, vers_const, sizeof (vers)) == 0) | |
207 | return TRUE; | |
208 | ||
209 | *errorptr = TRUE; | |
210 | return FALSE; | |
211 | } | |
212 | ||
213 | /* Read the WebAssembly header (magic number plus version number) from | |
214 | ABFD, setting ERRORPTR to TRUE if there is a mismatch. */ | |
215 | ||
216 | static bfd_boolean | |
217 | wasm_read_header (bfd *abfd, bfd_boolean *errorptr) | |
218 | { | |
219 | if (! wasm_read_magic (abfd, errorptr)) | |
220 | return FALSE; | |
221 | ||
222 | if (! wasm_read_version (abfd, errorptr)) | |
223 | return FALSE; | |
224 | ||
225 | return TRUE; | |
226 | } | |
227 | ||
228 | /* Scan the "function" subsection of the "name" section ASECT in the | |
229 | wasm module ABFD. Create symbols. Return TRUE on success. */ | |
230 | ||
231 | static bfd_boolean | |
232 | wasm_scan_name_function_section (bfd *abfd, sec_ptr asect) | |
233 | { | |
234 | bfd_byte *p; | |
235 | bfd_byte *end; | |
236 | bfd_vma payload_size; | |
237 | bfd_vma symcount = 0; | |
238 | tdata_type *tdata = abfd->tdata.any; | |
239 | asymbol *symbols = NULL; | |
240 | sec_ptr space_function_index; | |
241 | ||
242 | if (! asect) | |
243 | return FALSE; | |
244 | ||
245 | if (strcmp (asect->name, WASM_NAME_SECTION) != 0) | |
246 | return FALSE; | |
247 | ||
248 | p = asect->contents; | |
249 | end = asect->contents + asect->size; | |
250 | ||
251 | if (! p) | |
252 | return FALSE; | |
253 | ||
254 | while (p < end) | |
255 | { | |
256 | bfd_byte subsection_code = *p++; | |
257 | if (subsection_code == WASM_FUNCTION_SUBSECTION) | |
07d6d2b8 | 258 | break; |
a6be0538 PC |
259 | |
260 | /* subsection_code is documented to be a varuint7, meaning that | |
07d6d2b8 AM |
261 | it has to be a single byte in the 0 - 127 range. If it isn't, |
262 | the spec must have changed underneath us, so give up. */ | |
a6be0538 | 263 | if (subsection_code & 0x80) |
07d6d2b8 | 264 | return FALSE; |
a6be0538 PC |
265 | |
266 | READ_LEB128 (payload_size, p, end); | |
267 | ||
268 | if (p > p + payload_size) | |
07d6d2b8 | 269 | return FALSE; |
a6be0538 PC |
270 | |
271 | p += payload_size; | |
272 | } | |
273 | ||
274 | if (p >= end) | |
275 | return FALSE; | |
276 | ||
277 | READ_LEB128 (payload_size, p, end); | |
278 | ||
279 | if (p > p + payload_size) | |
280 | return FALSE; | |
281 | ||
282 | if (p + payload_size > end) | |
283 | return FALSE; | |
284 | ||
285 | end = p + payload_size; | |
286 | ||
287 | READ_LEB128 (symcount, p, end); | |
288 | ||
289 | /* Sanity check: each symbol has at least two bytes. */ | |
290 | if (symcount > payload_size/2) | |
291 | return FALSE; | |
292 | ||
293 | tdata->symcount = symcount; | |
294 | ||
295 | space_function_index = bfd_make_section_with_flags | |
296 | (abfd, WASM_SECTION_FUNCTION_INDEX, SEC_READONLY | SEC_CODE); | |
297 | ||
298 | if (! space_function_index) | |
299 | space_function_index = bfd_get_section_by_name (abfd, WASM_SECTION_FUNCTION_INDEX); | |
300 | ||
301 | if (! space_function_index) | |
302 | return FALSE; | |
303 | ||
304 | symbols = bfd_zalloc (abfd, tdata->symcount * sizeof (asymbol)); | |
305 | if (! symbols) | |
306 | return FALSE; | |
307 | ||
308 | for (symcount = 0; p < end && symcount < tdata->symcount; symcount++) | |
309 | { | |
87993319 | 310 | bfd_vma idx; |
a6be0538 PC |
311 | bfd_vma len; |
312 | char *name; | |
313 | asymbol *sym; | |
314 | ||
87993319 | 315 | READ_LEB128 (idx, p, end); |
a6be0538 PC |
316 | READ_LEB128 (len, p, end); |
317 | ||
318 | if (p + len < p || p + len > end) | |
07d6d2b8 | 319 | goto error_return; |
a6be0538 PC |
320 | |
321 | name = bfd_zalloc (abfd, len + 1); | |
322 | if (! name) | |
07d6d2b8 | 323 | goto error_return; |
a6be0538 PC |
324 | |
325 | memcpy (name, p, len); | |
326 | p += len; | |
327 | ||
328 | sym = &symbols[symcount]; | |
329 | sym->the_bfd = abfd; | |
330 | sym->name = name; | |
87993319 | 331 | sym->value = idx; |
a6be0538 PC |
332 | sym->flags = BSF_GLOBAL | BSF_FUNCTION; |
333 | sym->section = space_function_index; | |
334 | sym->udata.p = NULL; | |
335 | } | |
336 | ||
337 | if (symcount < tdata->symcount) | |
338 | goto error_return; | |
339 | ||
340 | tdata->symbols = symbols; | |
341 | abfd->symcount = symcount; | |
342 | ||
343 | return TRUE; | |
344 | ||
345 | error_return: | |
346 | while (symcount) | |
347 | bfd_release (abfd, (void *)symbols[--symcount].name); | |
348 | bfd_release (abfd, symbols); | |
349 | return FALSE; | |
350 | } | |
351 | ||
352 | /* Read a byte from ABFD and return it, or EOF for EOF or error. | |
353 | Set ERRORPTR on non-EOF error. */ | |
354 | ||
355 | static int | |
356 | wasm_read_byte (bfd *abfd, bfd_boolean *errorptr) | |
357 | { | |
358 | bfd_byte byte; | |
359 | ||
360 | if (bfd_bread (&byte, (bfd_size_type) 1, abfd) != 1) | |
361 | { | |
362 | if (bfd_get_error () != bfd_error_file_truncated) | |
07d6d2b8 | 363 | *errorptr = TRUE; |
a6be0538 PC |
364 | return EOF; |
365 | } | |
366 | ||
367 | return byte; | |
368 | } | |
369 | ||
370 | /* Scan the wasm module ABFD, creating sections and symbols. | |
371 | Return TRUE on success. */ | |
372 | ||
373 | static bfd_boolean | |
374 | wasm_scan (bfd *abfd) | |
375 | { | |
376 | bfd_boolean error = FALSE; | |
377 | /* Fake VMAs for now. Choose 0x80000000 as base to avoid clashes | |
378 | with actual data addresses. */ | |
379 | bfd_vma vma = 0x80000000; | |
380 | int section_code; | |
381 | unsigned int bytes_read; | |
382 | char *name = NULL; | |
383 | asection *bfdsec; | |
384 | ||
385 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
386 | goto error_return; | |
387 | ||
388 | if (! wasm_read_header (abfd, &error)) | |
389 | goto error_return; | |
390 | ||
391 | while ((section_code = wasm_read_byte (abfd, &error)) != EOF) | |
392 | { | |
393 | if (section_code != 0) | |
07d6d2b8 AM |
394 | { |
395 | const char *sname = wasm_section_code_to_name (section_code); | |
396 | ||
397 | if (! sname) | |
398 | goto error_return; | |
399 | ||
400 | name = strdup (sname); | |
401 | bfdsec = bfd_make_section_anyway_with_flags (abfd, name, SEC_HAS_CONTENTS); | |
402 | if (bfdsec == NULL) | |
403 | goto error_return; | |
404 | name = NULL; | |
405 | ||
406 | bfdsec->vma = vma; | |
407 | bfdsec->lma = vma; | |
408 | bfdsec->size = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
409 | if (error) | |
410 | goto error_return; | |
411 | bfdsec->filepos = bfd_tell (abfd); | |
412 | bfdsec->alignment_power = 0; | |
413 | } | |
a6be0538 | 414 | else |
07d6d2b8 AM |
415 | { |
416 | bfd_vma payload_len; | |
417 | file_ptr section_start; | |
418 | bfd_vma namelen; | |
419 | char *prefix = WASM_SECTION_PREFIX; | |
420 | char *p; | |
421 | int ret; | |
422 | ||
423 | payload_len = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
424 | if (error) | |
425 | goto error_return; | |
426 | section_start = bfd_tell (abfd); | |
427 | namelen = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
428 | if (error || namelen > payload_len) | |
429 | goto error_return; | |
430 | name = bfd_zmalloc (namelen + strlen (prefix) + 1); | |
431 | if (! name) | |
432 | goto error_return; | |
433 | p = name; | |
434 | ret = sprintf (p, "%s", prefix); | |
435 | if (ret < 0 || (bfd_vma) ret != strlen (prefix)) | |
436 | goto error_return; | |
437 | p += ret; | |
438 | if (bfd_bread (p, namelen, abfd) != namelen) | |
a6be0538 PC |
439 | goto error_return; |
440 | ||
07d6d2b8 AM |
441 | bfdsec = bfd_make_section_anyway_with_flags (abfd, name, SEC_HAS_CONTENTS); |
442 | if (bfdsec == NULL) | |
443 | goto error_return; | |
444 | name = NULL; | |
a6be0538 | 445 | |
07d6d2b8 AM |
446 | bfdsec->vma = vma; |
447 | bfdsec->lma = vma; | |
448 | bfdsec->filepos = bfd_tell (abfd); | |
449 | bfdsec->size = section_start + payload_len - bfdsec->filepos; | |
450 | bfdsec->alignment_power = 0; | |
451 | } | |
a6be0538 PC |
452 | |
453 | if (bfdsec->size != 0) | |
07d6d2b8 AM |
454 | { |
455 | bfdsec->contents = bfd_zalloc (abfd, bfdsec->size); | |
456 | if (! bfdsec->contents) | |
457 | goto error_return; | |
a6be0538 | 458 | |
07d6d2b8 | 459 | if (bfd_bread (bfdsec->contents, bfdsec->size, abfd) != bfdsec->size) |
a6be0538 | 460 | goto error_return; |
07d6d2b8 | 461 | } |
a6be0538 PC |
462 | |
463 | vma += bfdsec->size; | |
464 | } | |
465 | ||
466 | /* Make sure we're at actual EOF. There's no indication in the | |
467 | WebAssembly format of how long the file is supposed to be. */ | |
468 | if (error) | |
469 | goto error_return; | |
470 | ||
471 | return TRUE; | |
472 | ||
473 | error_return: | |
474 | if (name) | |
475 | free (name); | |
476 | ||
477 | for (bfdsec = abfd->sections; bfdsec; bfdsec = bfdsec->next) | |
478 | free ((void *) bfdsec->name); | |
479 | ||
480 | return FALSE; | |
481 | } | |
482 | ||
483 | /* Put a numbered section ASECT of ABFD into the table of numbered | |
484 | sections pointed to by FSARG. */ | |
485 | ||
486 | static void | |
487 | wasm_register_section (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 | 488 | asection *asect, |
a6be0538 PC |
489 | void *fsarg) |
490 | { | |
491 | sec_ptr *numbered_sections = fsarg; | |
87993319 | 492 | int idx = wasm_section_name_to_code (asect->name); |
a6be0538 | 493 | |
87993319 | 494 | if (idx == 0) |
a6be0538 PC |
495 | return; |
496 | ||
87993319 | 497 | numbered_sections[idx] = asect; |
a6be0538 PC |
498 | } |
499 | ||
500 | struct compute_section_arg | |
501 | { | |
502 | bfd_vma pos; | |
503 | bfd_boolean failed; | |
504 | }; | |
505 | ||
506 | /* Compute the file position of ABFD's section ASECT. FSARG is a | |
507 | pointer to the current file position. | |
508 | ||
509 | We allow section names of the form .wasm.id to encode the numbered | |
510 | section with ID id, if it exists; otherwise, a custom section with | |
511 | ID "id" is produced. Arbitrary section names are for sections that | |
512 | are assumed already to contain a section header; those are appended | |
513 | to the WebAssembly module verbatim. */ | |
514 | ||
515 | static void | |
516 | wasm_compute_custom_section_file_position (bfd *abfd, | |
517 | sec_ptr asect, | |
07d6d2b8 | 518 | void *fsarg) |
a6be0538 PC |
519 | { |
520 | struct compute_section_arg *fs = fsarg; | |
87993319 | 521 | int idx; |
a6be0538 PC |
522 | |
523 | if (fs->failed) | |
524 | return; | |
525 | ||
87993319 | 526 | idx = wasm_section_name_to_code (asect->name); |
a6be0538 | 527 | |
87993319 | 528 | if (idx != 0) |
a6be0538 PC |
529 | return; |
530 | ||
531 | if (CONST_STRNEQ (asect->name, WASM_SECTION_PREFIX)) | |
532 | { | |
533 | const char *name = asect->name + strlen (WASM_SECTION_PREFIX); | |
534 | bfd_size_type payload_len = asect->size; | |
535 | bfd_size_type name_len = strlen (name); | |
536 | bfd_size_type nl = name_len; | |
537 | ||
538 | payload_len += name_len; | |
539 | ||
540 | do | |
07d6d2b8 AM |
541 | { |
542 | payload_len++; | |
543 | nl >>= 7; | |
544 | } | |
a6be0538 PC |
545 | while (nl); |
546 | ||
547 | bfd_seek (abfd, fs->pos, SEEK_SET); | |
548 | if (! wasm_write_uleb128 (abfd, 0) | |
07d6d2b8 AM |
549 | || ! wasm_write_uleb128 (abfd, payload_len) |
550 | || ! wasm_write_uleb128 (abfd, name_len) | |
551 | || bfd_bwrite (name, name_len, abfd) != name_len) | |
552 | goto error_return; | |
a6be0538 PC |
553 | fs->pos = asect->filepos = bfd_tell (abfd); |
554 | } | |
555 | else | |
556 | { | |
557 | asect->filepos = fs->pos; | |
558 | } | |
559 | ||
560 | ||
561 | fs->pos += asect->size; | |
562 | return; | |
563 | ||
564 | error_return: | |
565 | fs->failed = TRUE; | |
566 | } | |
567 | ||
568 | /* Compute the file positions for the sections of ABFD. Currently, | |
569 | this writes all numbered sections first, in order, then all custom | |
570 | sections, in section order. | |
571 | ||
572 | The spec says that the numbered sections must appear in order of | |
573 | their ids, but custom sections can appear in any position and any | |
574 | order, and more than once. FIXME: support that. */ | |
575 | ||
576 | static bfd_boolean | |
577 | wasm_compute_section_file_positions (bfd *abfd) | |
578 | { | |
579 | bfd_byte magic[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
580 | bfd_byte vers[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
581 | sec_ptr numbered_sections[WASM_NUMBERED_SECTIONS]; | |
582 | struct compute_section_arg fs; | |
583 | unsigned int i; | |
584 | ||
585 | bfd_seek (abfd, (bfd_vma) 0, SEEK_SET); | |
586 | ||
587 | if (bfd_bwrite (magic, sizeof (magic), abfd) != (sizeof magic) | |
588 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
589 | return FALSE; | |
590 | ||
591 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
592 | numbered_sections[i] = NULL; | |
593 | ||
594 | bfd_map_over_sections (abfd, wasm_register_section, numbered_sections); | |
595 | ||
596 | fs.pos = bfd_tell (abfd); | |
597 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
598 | { | |
599 | sec_ptr sec = numbered_sections[i]; | |
600 | bfd_size_type size; | |
601 | ||
602 | if (! sec) | |
07d6d2b8 | 603 | continue; |
a6be0538 PC |
604 | size = sec->size; |
605 | if (bfd_seek (abfd, fs.pos, SEEK_SET) != 0) | |
07d6d2b8 | 606 | return FALSE; |
a6be0538 | 607 | if (! wasm_write_uleb128 (abfd, i) |
07d6d2b8 AM |
608 | || ! wasm_write_uleb128 (abfd, size)) |
609 | return FALSE; | |
a6be0538 PC |
610 | fs.pos = sec->filepos = bfd_tell (abfd); |
611 | fs.pos += size; | |
612 | } | |
613 | ||
614 | fs.failed = FALSE; | |
615 | ||
616 | bfd_map_over_sections (abfd, wasm_compute_custom_section_file_position, &fs); | |
617 | ||
618 | if (fs.failed) | |
619 | return FALSE; | |
620 | ||
621 | abfd->output_has_begun = TRUE; | |
622 | ||
623 | return TRUE; | |
624 | } | |
625 | ||
626 | static bfd_boolean | |
627 | wasm_set_section_contents (bfd *abfd, | |
07d6d2b8 AM |
628 | sec_ptr section, |
629 | const void *location, | |
630 | file_ptr offset, | |
631 | bfd_size_type count) | |
a6be0538 PC |
632 | { |
633 | if (count == 0) | |
634 | return TRUE; | |
635 | ||
636 | if (! abfd->output_has_begun | |
637 | && ! wasm_compute_section_file_positions (abfd)) | |
638 | return FALSE; | |
639 | ||
640 | if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 | |
641 | || bfd_bwrite (location, count, abfd) != count) | |
642 | return FALSE; | |
643 | ||
644 | return TRUE; | |
645 | } | |
646 | ||
647 | static bfd_boolean | |
648 | wasm_write_object_contents (bfd* abfd) | |
649 | { | |
650 | bfd_byte magic[] = WASM_MAGIC; | |
651 | bfd_byte vers[] = WASM_VERSION; | |
652 | ||
653 | if (bfd_seek (abfd, 0, SEEK_SET) != 0) | |
654 | return FALSE; | |
655 | ||
656 | if (bfd_bwrite (magic, sizeof (magic), abfd) != sizeof (magic) | |
657 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
658 | return FALSE; | |
659 | ||
660 | return TRUE; | |
661 | } | |
662 | ||
663 | static bfd_boolean | |
664 | wasm_mkobject (bfd *abfd) | |
665 | { | |
666 | tdata_type *tdata = (tdata_type *) bfd_alloc (abfd, sizeof (tdata_type)); | |
667 | ||
668 | if (! tdata) | |
669 | return FALSE; | |
670 | ||
671 | tdata->symbols = NULL; | |
672 | tdata->symcount = 0; | |
673 | ||
674 | abfd->tdata.any = tdata; | |
675 | ||
676 | return TRUE; | |
677 | } | |
678 | ||
679 | static long | |
680 | wasm_get_symtab_upper_bound (bfd *abfd) | |
681 | { | |
682 | tdata_type *tdata = abfd->tdata.any; | |
683 | ||
684 | return (tdata->symcount + 1) * (sizeof (asymbol *)); | |
685 | } | |
686 | ||
687 | static long | |
688 | wasm_canonicalize_symtab (bfd *abfd, asymbol **alocation) | |
689 | { | |
690 | tdata_type *tdata = abfd->tdata.any; | |
691 | size_t i; | |
692 | ||
693 | for (i = 0; i < tdata->symcount; i++) | |
694 | alocation[i] = &tdata->symbols[i]; | |
695 | alocation[i] = NULL; | |
696 | ||
697 | return tdata->symcount; | |
698 | } | |
699 | ||
700 | static asymbol * | |
701 | wasm_make_empty_symbol (bfd *abfd) | |
702 | { | |
703 | bfd_size_type amt = sizeof (asymbol); | |
704 | asymbol *new_symbol = (asymbol *) bfd_zalloc (abfd, amt); | |
705 | ||
706 | if (! new_symbol) | |
707 | return NULL; | |
708 | new_symbol->the_bfd = abfd; | |
709 | return new_symbol; | |
710 | } | |
711 | ||
712 | static void | |
713 | wasm_print_symbol (bfd *abfd, | |
07d6d2b8 AM |
714 | void * filep, |
715 | asymbol *symbol, | |
716 | bfd_print_symbol_type how) | |
a6be0538 PC |
717 | { |
718 | FILE *file = (FILE *) filep; | |
719 | ||
720 | switch (how) | |
721 | { | |
722 | case bfd_print_symbol_name: | |
723 | fprintf (file, "%s", symbol->name); | |
724 | break; | |
725 | ||
726 | default: | |
727 | bfd_print_symbol_vandf (abfd, filep, symbol); | |
728 | fprintf (file, " %-5s %s", symbol->section->name, symbol->name); | |
729 | } | |
730 | } | |
731 | ||
732 | static void | |
733 | wasm_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 AM |
734 | asymbol *symbol, |
735 | symbol_info *ret) | |
a6be0538 PC |
736 | { |
737 | bfd_symbol_info (symbol, ret); | |
738 | } | |
739 | ||
740 | /* Check whether ABFD is a WebAssembly module; if so, scan it. */ | |
741 | ||
742 | static const bfd_target * | |
743 | wasm_object_p (bfd *abfd) | |
744 | { | |
745 | bfd_boolean error; | |
746 | ||
747 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
748 | return NULL; | |
749 | ||
750 | if (! wasm_read_header (abfd, &error)) | |
751 | { | |
752 | bfd_set_error (bfd_error_wrong_format); | |
753 | return NULL; | |
754 | } | |
755 | ||
756 | if (! wasm_mkobject (abfd) || ! wasm_scan (abfd)) | |
757 | return NULL; | |
758 | ||
759 | if (! bfd_default_set_arch_mach (abfd, bfd_arch_wasm32, 0)) | |
760 | return NULL; | |
761 | ||
762 | if (wasm_scan_name_function_section (abfd, bfd_get_section_by_name (abfd, WASM_NAME_SECTION))) | |
763 | abfd->flags |= HAS_SYMS; | |
764 | ||
765 | return abfd->xvec; | |
766 | } | |
767 | ||
768 | /* BFD_JUMP_TABLE_WRITE */ | |
07d6d2b8 | 769 | #define wasm_set_arch_mach _bfd_generic_set_arch_mach |
a6be0538 PC |
770 | |
771 | /* BFD_JUMP_TABLE_SYMBOLS */ | |
07d6d2b8 AM |
772 | #define wasm_get_symbol_version_string _bfd_nosymbols_get_symbol_version_string |
773 | #define wasm_bfd_is_local_label_name bfd_generic_is_local_label_name | |
d00dd7dc | 774 | #define wasm_bfd_is_target_special_symbol _bfd_bool_bfd_asymbol_false |
07d6d2b8 AM |
775 | #define wasm_get_lineno _bfd_nosymbols_get_lineno |
776 | #define wasm_find_nearest_line _bfd_nosymbols_find_nearest_line | |
777 | #define wasm_find_line _bfd_nosymbols_find_line | |
778 | #define wasm_find_inliner_info _bfd_nosymbols_find_inliner_info | |
779 | #define wasm_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol | |
780 | #define wasm_read_minisymbols _bfd_generic_read_minisymbols | |
781 | #define wasm_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol | |
a6be0538 PC |
782 | |
783 | const bfd_target wasm_vec = | |
784 | { | |
07d6d2b8 | 785 | "wasm", /* Name. */ |
a6be0538 PC |
786 | bfd_target_unknown_flavour, |
787 | BFD_ENDIAN_LITTLE, | |
788 | BFD_ENDIAN_LITTLE, | |
789 | (HAS_SYMS | WP_TEXT), /* Object flags. */ | |
790 | (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS), /* Section flags. */ | |
07d6d2b8 AM |
791 | 0, /* Leading underscore. */ |
792 | ' ', /* AR_pad_char. */ | |
793 | 255, /* AR_max_namelen. */ | |
a6be0538 PC |
794 | 0, /* Match priority. */ |
795 | /* Routines to byte-swap various sized integers from the data sections. */ | |
796 | bfd_getl64, bfd_getl_signed_64, bfd_putl64, | |
797 | bfd_getl32, bfd_getl_signed_32, bfd_putl32, | |
798 | bfd_getl16, bfd_getl_signed_16, bfd_putl16, | |
799 | ||
800 | /* Routines to byte-swap various sized integers from the file headers. */ | |
801 | bfd_getl64, bfd_getl_signed_64, bfd_putl64, | |
802 | bfd_getl32, bfd_getl_signed_32, bfd_putl32, | |
803 | bfd_getl16, bfd_getl_signed_16, bfd_putl16, | |
804 | ||
805 | { | |
806 | _bfd_dummy_target, | |
807 | wasm_object_p, /* bfd_check_format. */ | |
808 | _bfd_dummy_target, | |
809 | _bfd_dummy_target, | |
810 | }, | |
811 | { | |
d00dd7dc | 812 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
813 | wasm_mkobject, |
814 | _bfd_generic_mkarchive, | |
d00dd7dc | 815 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
816 | }, |
817 | { /* bfd_write_contents. */ | |
d00dd7dc | 818 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
819 | wasm_write_object_contents, |
820 | _bfd_write_archive_contents, | |
d00dd7dc | 821 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
822 | }, |
823 | ||
824 | BFD_JUMP_TABLE_GENERIC (_bfd_generic), | |
825 | BFD_JUMP_TABLE_COPY (_bfd_generic), | |
826 | BFD_JUMP_TABLE_CORE (_bfd_nocore), | |
827 | BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), | |
828 | BFD_JUMP_TABLE_SYMBOLS (wasm), | |
829 | BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), | |
830 | BFD_JUMP_TABLE_WRITE (wasm), | |
831 | BFD_JUMP_TABLE_LINK (_bfd_nolink), | |
832 | BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), | |
833 | ||
834 | NULL, | |
835 | ||
836 | NULL, | |
837 | }; |