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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; | |
27c1c427 | 114 | int status = 1; |
a6be0538 PC |
115 | |
116 | while (bfd_bread (&byte, 1, abfd) == 1) | |
117 | { | |
118 | num_read++; | |
119 | ||
27c1c427 AM |
120 | if (shift < sizeof (result) * 8) |
121 | { | |
122 | result |= ((bfd_vma) (byte & 0x7f)) << shift; | |
123 | if ((result >> shift) != (byte & 0x7f)) | |
124 | /* Overflow. */ | |
125 | status |= 2; | |
126 | shift += 7; | |
127 | } | |
128 | else if ((byte & 0x7f) != 0) | |
129 | status |= 2; | |
a6be0538 | 130 | |
a6be0538 | 131 | if ((byte & 0x80) == 0) |
07d6d2b8 | 132 | { |
27c1c427 AM |
133 | status &= ~1; |
134 | if (sign && (shift < 8 * sizeof (result)) && (byte & 0x40)) | |
135 | result |= -((bfd_vma) 1 << shift); | |
07d6d2b8 AM |
136 | break; |
137 | } | |
a6be0538 PC |
138 | } |
139 | ||
140 | if (length_return != NULL) | |
141 | *length_return = num_read; | |
142 | if (error_return != NULL) | |
27c1c427 | 143 | *error_return = status != 0; |
a6be0538 PC |
144 | |
145 | return result; | |
146 | } | |
147 | ||
148 | /* Encode an integer V as LEB128 and write it to ABFD, return TRUE on | |
149 | success. */ | |
150 | ||
151 | static bfd_boolean | |
152 | wasm_write_uleb128 (bfd *abfd, bfd_vma v) | |
153 | { | |
154 | do | |
155 | { | |
156 | bfd_byte c = v & 0x7f; | |
157 | v >>= 7; | |
158 | ||
159 | if (v) | |
07d6d2b8 | 160 | c |= 0x80; |
a6be0538 PC |
161 | |
162 | if (bfd_bwrite (&c, 1, abfd) != 1) | |
07d6d2b8 | 163 | return FALSE; |
a6be0538 PC |
164 | } |
165 | while (v); | |
166 | ||
167 | return TRUE; | |
168 | } | |
169 | ||
170 | /* Read the LEB128 integer at P, saving it to X; at end of buffer, | |
171 | jump to error_return. */ | |
07d6d2b8 AM |
172 | #define READ_LEB128(x, p, end) \ |
173 | do \ | |
174 | { \ | |
175 | unsigned int length_read; \ | |
176 | (x) = _bfd_safe_read_leb128 (abfd, (p), &length_read, \ | |
177 | FALSE, (end)); \ | |
178 | (p) += length_read; \ | |
179 | if (length_read == 0) \ | |
180 | goto error_return; \ | |
181 | } \ | |
a6be0538 PC |
182 | while (0) |
183 | ||
184 | /* Verify the magic number at the beginning of a WebAssembly module | |
185 | ABFD, setting ERRORPTR if there's a mismatch. */ | |
186 | ||
187 | static bfd_boolean | |
188 | wasm_read_magic (bfd *abfd, bfd_boolean *errorptr) | |
189 | { | |
190 | bfd_byte magic_const[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
191 | bfd_byte magic[SIZEOF_WASM_MAGIC]; | |
192 | ||
193 | if (bfd_bread (magic, sizeof (magic), abfd) == sizeof (magic) | |
194 | && memcmp (magic, magic_const, sizeof (magic)) == 0) | |
195 | return TRUE; | |
196 | ||
197 | *errorptr = TRUE; | |
198 | return FALSE; | |
199 | } | |
200 | ||
201 | /* Read the version number from ABFD, returning TRUE if it's a supported | |
202 | version. Set ERRORPTR otherwise. */ | |
203 | ||
204 | static bfd_boolean | |
205 | wasm_read_version (bfd *abfd, bfd_boolean *errorptr) | |
206 | { | |
207 | bfd_byte vers_const[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
208 | bfd_byte vers[SIZEOF_WASM_VERSION]; | |
209 | ||
210 | if (bfd_bread (vers, sizeof (vers), abfd) == sizeof (vers) | |
211 | /* Don't attempt to parse newer versions, which are likely to | |
212 | require code changes. */ | |
213 | && memcmp (vers, vers_const, sizeof (vers)) == 0) | |
214 | return TRUE; | |
215 | ||
216 | *errorptr = TRUE; | |
217 | return FALSE; | |
218 | } | |
219 | ||
220 | /* Read the WebAssembly header (magic number plus version number) from | |
221 | ABFD, setting ERRORPTR to TRUE if there is a mismatch. */ | |
222 | ||
223 | static bfd_boolean | |
224 | wasm_read_header (bfd *abfd, bfd_boolean *errorptr) | |
225 | { | |
226 | if (! wasm_read_magic (abfd, errorptr)) | |
227 | return FALSE; | |
228 | ||
229 | if (! wasm_read_version (abfd, errorptr)) | |
230 | return FALSE; | |
231 | ||
232 | return TRUE; | |
233 | } | |
234 | ||
235 | /* Scan the "function" subsection of the "name" section ASECT in the | |
236 | wasm module ABFD. Create symbols. Return TRUE on success. */ | |
237 | ||
238 | static bfd_boolean | |
239 | wasm_scan_name_function_section (bfd *abfd, sec_ptr asect) | |
240 | { | |
241 | bfd_byte *p; | |
242 | bfd_byte *end; | |
243 | bfd_vma payload_size; | |
244 | bfd_vma symcount = 0; | |
245 | tdata_type *tdata = abfd->tdata.any; | |
246 | asymbol *symbols = NULL; | |
247 | sec_ptr space_function_index; | |
248 | ||
249 | if (! asect) | |
250 | return FALSE; | |
251 | ||
252 | if (strcmp (asect->name, WASM_NAME_SECTION) != 0) | |
253 | return FALSE; | |
254 | ||
255 | p = asect->contents; | |
256 | end = asect->contents + asect->size; | |
257 | ||
258 | if (! p) | |
259 | return FALSE; | |
260 | ||
261 | while (p < end) | |
262 | { | |
263 | bfd_byte subsection_code = *p++; | |
264 | if (subsection_code == WASM_FUNCTION_SUBSECTION) | |
07d6d2b8 | 265 | break; |
a6be0538 PC |
266 | |
267 | /* subsection_code is documented to be a varuint7, meaning that | |
07d6d2b8 AM |
268 | it has to be a single byte in the 0 - 127 range. If it isn't, |
269 | the spec must have changed underneath us, so give up. */ | |
a6be0538 | 270 | if (subsection_code & 0x80) |
07d6d2b8 | 271 | return FALSE; |
a6be0538 PC |
272 | |
273 | READ_LEB128 (payload_size, p, end); | |
274 | ||
275 | if (p > p + payload_size) | |
07d6d2b8 | 276 | return FALSE; |
a6be0538 PC |
277 | |
278 | p += payload_size; | |
279 | } | |
280 | ||
281 | if (p >= end) | |
282 | return FALSE; | |
283 | ||
284 | READ_LEB128 (payload_size, p, end); | |
285 | ||
286 | if (p > p + payload_size) | |
287 | return FALSE; | |
288 | ||
289 | if (p + payload_size > end) | |
290 | return FALSE; | |
291 | ||
292 | end = p + payload_size; | |
293 | ||
294 | READ_LEB128 (symcount, p, end); | |
295 | ||
296 | /* Sanity check: each symbol has at least two bytes. */ | |
297 | if (symcount > payload_size/2) | |
298 | return FALSE; | |
299 | ||
300 | tdata->symcount = symcount; | |
301 | ||
302 | space_function_index = bfd_make_section_with_flags | |
303 | (abfd, WASM_SECTION_FUNCTION_INDEX, SEC_READONLY | SEC_CODE); | |
304 | ||
305 | if (! space_function_index) | |
306 | space_function_index = bfd_get_section_by_name (abfd, WASM_SECTION_FUNCTION_INDEX); | |
307 | ||
308 | if (! space_function_index) | |
309 | return FALSE; | |
310 | ||
311 | symbols = bfd_zalloc (abfd, tdata->symcount * sizeof (asymbol)); | |
312 | if (! symbols) | |
313 | return FALSE; | |
314 | ||
315 | for (symcount = 0; p < end && symcount < tdata->symcount; symcount++) | |
316 | { | |
87993319 | 317 | bfd_vma idx; |
a6be0538 PC |
318 | bfd_vma len; |
319 | char *name; | |
320 | asymbol *sym; | |
321 | ||
87993319 | 322 | READ_LEB128 (idx, p, end); |
a6be0538 PC |
323 | READ_LEB128 (len, p, end); |
324 | ||
325 | if (p + len < p || p + len > end) | |
07d6d2b8 | 326 | goto error_return; |
a6be0538 PC |
327 | |
328 | name = bfd_zalloc (abfd, len + 1); | |
329 | if (! name) | |
07d6d2b8 | 330 | goto error_return; |
a6be0538 PC |
331 | |
332 | memcpy (name, p, len); | |
333 | p += len; | |
334 | ||
335 | sym = &symbols[symcount]; | |
336 | sym->the_bfd = abfd; | |
337 | sym->name = name; | |
87993319 | 338 | sym->value = idx; |
a6be0538 PC |
339 | sym->flags = BSF_GLOBAL | BSF_FUNCTION; |
340 | sym->section = space_function_index; | |
341 | sym->udata.p = NULL; | |
342 | } | |
343 | ||
344 | if (symcount < tdata->symcount) | |
345 | goto error_return; | |
346 | ||
347 | tdata->symbols = symbols; | |
348 | abfd->symcount = symcount; | |
349 | ||
350 | return TRUE; | |
351 | ||
352 | error_return: | |
353 | while (symcount) | |
354 | bfd_release (abfd, (void *)symbols[--symcount].name); | |
355 | bfd_release (abfd, symbols); | |
356 | return FALSE; | |
357 | } | |
358 | ||
359 | /* Read a byte from ABFD and return it, or EOF for EOF or error. | |
360 | Set ERRORPTR on non-EOF error. */ | |
361 | ||
362 | static int | |
363 | wasm_read_byte (bfd *abfd, bfd_boolean *errorptr) | |
364 | { | |
365 | bfd_byte byte; | |
366 | ||
367 | if (bfd_bread (&byte, (bfd_size_type) 1, abfd) != 1) | |
368 | { | |
369 | if (bfd_get_error () != bfd_error_file_truncated) | |
07d6d2b8 | 370 | *errorptr = TRUE; |
a6be0538 PC |
371 | return EOF; |
372 | } | |
373 | ||
374 | return byte; | |
375 | } | |
376 | ||
377 | /* Scan the wasm module ABFD, creating sections and symbols. | |
378 | Return TRUE on success. */ | |
379 | ||
380 | static bfd_boolean | |
381 | wasm_scan (bfd *abfd) | |
382 | { | |
383 | bfd_boolean error = FALSE; | |
384 | /* Fake VMAs for now. Choose 0x80000000 as base to avoid clashes | |
385 | with actual data addresses. */ | |
386 | bfd_vma vma = 0x80000000; | |
387 | int section_code; | |
388 | unsigned int bytes_read; | |
389 | char *name = NULL; | |
390 | asection *bfdsec; | |
391 | ||
392 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
393 | goto error_return; | |
394 | ||
395 | if (! wasm_read_header (abfd, &error)) | |
396 | goto error_return; | |
397 | ||
398 | while ((section_code = wasm_read_byte (abfd, &error)) != EOF) | |
399 | { | |
400 | if (section_code != 0) | |
07d6d2b8 AM |
401 | { |
402 | const char *sname = wasm_section_code_to_name (section_code); | |
403 | ||
404 | if (! sname) | |
405 | goto error_return; | |
406 | ||
407 | name = strdup (sname); | |
408 | bfdsec = bfd_make_section_anyway_with_flags (abfd, name, SEC_HAS_CONTENTS); | |
409 | if (bfdsec == NULL) | |
410 | goto error_return; | |
411 | name = NULL; | |
412 | ||
413 | bfdsec->vma = vma; | |
414 | bfdsec->lma = vma; | |
415 | bfdsec->size = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
416 | if (error) | |
417 | goto error_return; | |
418 | bfdsec->filepos = bfd_tell (abfd); | |
419 | bfdsec->alignment_power = 0; | |
420 | } | |
a6be0538 | 421 | else |
07d6d2b8 AM |
422 | { |
423 | bfd_vma payload_len; | |
424 | file_ptr section_start; | |
425 | bfd_vma namelen; | |
426 | char *prefix = WASM_SECTION_PREFIX; | |
427 | char *p; | |
428 | int ret; | |
429 | ||
430 | payload_len = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
431 | if (error) | |
432 | goto error_return; | |
433 | section_start = bfd_tell (abfd); | |
434 | namelen = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
435 | if (error || namelen > payload_len) | |
436 | goto error_return; | |
437 | name = bfd_zmalloc (namelen + strlen (prefix) + 1); | |
438 | if (! name) | |
439 | goto error_return; | |
440 | p = name; | |
441 | ret = sprintf (p, "%s", prefix); | |
442 | if (ret < 0 || (bfd_vma) ret != strlen (prefix)) | |
443 | goto error_return; | |
444 | p += ret; | |
445 | if (bfd_bread (p, namelen, abfd) != namelen) | |
a6be0538 PC |
446 | goto error_return; |
447 | ||
07d6d2b8 AM |
448 | bfdsec = bfd_make_section_anyway_with_flags (abfd, name, SEC_HAS_CONTENTS); |
449 | if (bfdsec == NULL) | |
450 | goto error_return; | |
451 | name = NULL; | |
a6be0538 | 452 | |
07d6d2b8 AM |
453 | bfdsec->vma = vma; |
454 | bfdsec->lma = vma; | |
455 | bfdsec->filepos = bfd_tell (abfd); | |
456 | bfdsec->size = section_start + payload_len - bfdsec->filepos; | |
457 | bfdsec->alignment_power = 0; | |
458 | } | |
a6be0538 PC |
459 | |
460 | if (bfdsec->size != 0) | |
07d6d2b8 AM |
461 | { |
462 | bfdsec->contents = bfd_zalloc (abfd, bfdsec->size); | |
463 | if (! bfdsec->contents) | |
464 | goto error_return; | |
a6be0538 | 465 | |
07d6d2b8 | 466 | if (bfd_bread (bfdsec->contents, bfdsec->size, abfd) != bfdsec->size) |
a6be0538 | 467 | goto error_return; |
07d6d2b8 | 468 | } |
a6be0538 PC |
469 | |
470 | vma += bfdsec->size; | |
471 | } | |
472 | ||
473 | /* Make sure we're at actual EOF. There's no indication in the | |
474 | WebAssembly format of how long the file is supposed to be. */ | |
475 | if (error) | |
476 | goto error_return; | |
477 | ||
478 | return TRUE; | |
479 | ||
480 | error_return: | |
481 | if (name) | |
482 | free (name); | |
483 | ||
484 | for (bfdsec = abfd->sections; bfdsec; bfdsec = bfdsec->next) | |
485 | free ((void *) bfdsec->name); | |
486 | ||
487 | return FALSE; | |
488 | } | |
489 | ||
490 | /* Put a numbered section ASECT of ABFD into the table of numbered | |
491 | sections pointed to by FSARG. */ | |
492 | ||
493 | static void | |
494 | wasm_register_section (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 | 495 | asection *asect, |
a6be0538 PC |
496 | void *fsarg) |
497 | { | |
498 | sec_ptr *numbered_sections = fsarg; | |
87993319 | 499 | int idx = wasm_section_name_to_code (asect->name); |
a6be0538 | 500 | |
87993319 | 501 | if (idx == 0) |
a6be0538 PC |
502 | return; |
503 | ||
87993319 | 504 | numbered_sections[idx] = asect; |
a6be0538 PC |
505 | } |
506 | ||
507 | struct compute_section_arg | |
508 | { | |
509 | bfd_vma pos; | |
510 | bfd_boolean failed; | |
511 | }; | |
512 | ||
513 | /* Compute the file position of ABFD's section ASECT. FSARG is a | |
514 | pointer to the current file position. | |
515 | ||
516 | We allow section names of the form .wasm.id to encode the numbered | |
517 | section with ID id, if it exists; otherwise, a custom section with | |
518 | ID "id" is produced. Arbitrary section names are for sections that | |
519 | are assumed already to contain a section header; those are appended | |
520 | to the WebAssembly module verbatim. */ | |
521 | ||
522 | static void | |
523 | wasm_compute_custom_section_file_position (bfd *abfd, | |
524 | sec_ptr asect, | |
07d6d2b8 | 525 | void *fsarg) |
a6be0538 PC |
526 | { |
527 | struct compute_section_arg *fs = fsarg; | |
87993319 | 528 | int idx; |
a6be0538 PC |
529 | |
530 | if (fs->failed) | |
531 | return; | |
532 | ||
87993319 | 533 | idx = wasm_section_name_to_code (asect->name); |
a6be0538 | 534 | |
87993319 | 535 | if (idx != 0) |
a6be0538 PC |
536 | return; |
537 | ||
538 | if (CONST_STRNEQ (asect->name, WASM_SECTION_PREFIX)) | |
539 | { | |
540 | const char *name = asect->name + strlen (WASM_SECTION_PREFIX); | |
541 | bfd_size_type payload_len = asect->size; | |
542 | bfd_size_type name_len = strlen (name); | |
543 | bfd_size_type nl = name_len; | |
544 | ||
545 | payload_len += name_len; | |
546 | ||
547 | do | |
07d6d2b8 AM |
548 | { |
549 | payload_len++; | |
550 | nl >>= 7; | |
551 | } | |
a6be0538 PC |
552 | while (nl); |
553 | ||
554 | bfd_seek (abfd, fs->pos, SEEK_SET); | |
555 | if (! wasm_write_uleb128 (abfd, 0) | |
07d6d2b8 AM |
556 | || ! wasm_write_uleb128 (abfd, payload_len) |
557 | || ! wasm_write_uleb128 (abfd, name_len) | |
558 | || bfd_bwrite (name, name_len, abfd) != name_len) | |
559 | goto error_return; | |
a6be0538 PC |
560 | fs->pos = asect->filepos = bfd_tell (abfd); |
561 | } | |
562 | else | |
563 | { | |
564 | asect->filepos = fs->pos; | |
565 | } | |
566 | ||
567 | ||
568 | fs->pos += asect->size; | |
569 | return; | |
570 | ||
571 | error_return: | |
572 | fs->failed = TRUE; | |
573 | } | |
574 | ||
575 | /* Compute the file positions for the sections of ABFD. Currently, | |
576 | this writes all numbered sections first, in order, then all custom | |
577 | sections, in section order. | |
578 | ||
579 | The spec says that the numbered sections must appear in order of | |
580 | their ids, but custom sections can appear in any position and any | |
581 | order, and more than once. FIXME: support that. */ | |
582 | ||
583 | static bfd_boolean | |
584 | wasm_compute_section_file_positions (bfd *abfd) | |
585 | { | |
586 | bfd_byte magic[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
587 | bfd_byte vers[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
588 | sec_ptr numbered_sections[WASM_NUMBERED_SECTIONS]; | |
589 | struct compute_section_arg fs; | |
590 | unsigned int i; | |
591 | ||
592 | bfd_seek (abfd, (bfd_vma) 0, SEEK_SET); | |
593 | ||
594 | if (bfd_bwrite (magic, sizeof (magic), abfd) != (sizeof magic) | |
595 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
596 | return FALSE; | |
597 | ||
598 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
599 | numbered_sections[i] = NULL; | |
600 | ||
601 | bfd_map_over_sections (abfd, wasm_register_section, numbered_sections); | |
602 | ||
603 | fs.pos = bfd_tell (abfd); | |
604 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
605 | { | |
606 | sec_ptr sec = numbered_sections[i]; | |
607 | bfd_size_type size; | |
608 | ||
609 | if (! sec) | |
07d6d2b8 | 610 | continue; |
a6be0538 PC |
611 | size = sec->size; |
612 | if (bfd_seek (abfd, fs.pos, SEEK_SET) != 0) | |
07d6d2b8 | 613 | return FALSE; |
a6be0538 | 614 | if (! wasm_write_uleb128 (abfd, i) |
07d6d2b8 AM |
615 | || ! wasm_write_uleb128 (abfd, size)) |
616 | return FALSE; | |
a6be0538 PC |
617 | fs.pos = sec->filepos = bfd_tell (abfd); |
618 | fs.pos += size; | |
619 | } | |
620 | ||
621 | fs.failed = FALSE; | |
622 | ||
623 | bfd_map_over_sections (abfd, wasm_compute_custom_section_file_position, &fs); | |
624 | ||
625 | if (fs.failed) | |
626 | return FALSE; | |
627 | ||
628 | abfd->output_has_begun = TRUE; | |
629 | ||
630 | return TRUE; | |
631 | } | |
632 | ||
633 | static bfd_boolean | |
634 | wasm_set_section_contents (bfd *abfd, | |
07d6d2b8 AM |
635 | sec_ptr section, |
636 | const void *location, | |
637 | file_ptr offset, | |
638 | bfd_size_type count) | |
a6be0538 PC |
639 | { |
640 | if (count == 0) | |
641 | return TRUE; | |
642 | ||
643 | if (! abfd->output_has_begun | |
644 | && ! wasm_compute_section_file_positions (abfd)) | |
645 | return FALSE; | |
646 | ||
647 | if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 | |
648 | || bfd_bwrite (location, count, abfd) != count) | |
649 | return FALSE; | |
650 | ||
651 | return TRUE; | |
652 | } | |
653 | ||
654 | static bfd_boolean | |
655 | wasm_write_object_contents (bfd* abfd) | |
656 | { | |
657 | bfd_byte magic[] = WASM_MAGIC; | |
658 | bfd_byte vers[] = WASM_VERSION; | |
659 | ||
660 | if (bfd_seek (abfd, 0, SEEK_SET) != 0) | |
661 | return FALSE; | |
662 | ||
663 | if (bfd_bwrite (magic, sizeof (magic), abfd) != sizeof (magic) | |
664 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
665 | return FALSE; | |
666 | ||
667 | return TRUE; | |
668 | } | |
669 | ||
670 | static bfd_boolean | |
671 | wasm_mkobject (bfd *abfd) | |
672 | { | |
673 | tdata_type *tdata = (tdata_type *) bfd_alloc (abfd, sizeof (tdata_type)); | |
674 | ||
675 | if (! tdata) | |
676 | return FALSE; | |
677 | ||
678 | tdata->symbols = NULL; | |
679 | tdata->symcount = 0; | |
680 | ||
681 | abfd->tdata.any = tdata; | |
682 | ||
683 | return TRUE; | |
684 | } | |
685 | ||
686 | static long | |
687 | wasm_get_symtab_upper_bound (bfd *abfd) | |
688 | { | |
689 | tdata_type *tdata = abfd->tdata.any; | |
690 | ||
691 | return (tdata->symcount + 1) * (sizeof (asymbol *)); | |
692 | } | |
693 | ||
694 | static long | |
695 | wasm_canonicalize_symtab (bfd *abfd, asymbol **alocation) | |
696 | { | |
697 | tdata_type *tdata = abfd->tdata.any; | |
698 | size_t i; | |
699 | ||
700 | for (i = 0; i < tdata->symcount; i++) | |
701 | alocation[i] = &tdata->symbols[i]; | |
702 | alocation[i] = NULL; | |
703 | ||
704 | return tdata->symcount; | |
705 | } | |
706 | ||
707 | static asymbol * | |
708 | wasm_make_empty_symbol (bfd *abfd) | |
709 | { | |
710 | bfd_size_type amt = sizeof (asymbol); | |
711 | asymbol *new_symbol = (asymbol *) bfd_zalloc (abfd, amt); | |
712 | ||
713 | if (! new_symbol) | |
714 | return NULL; | |
715 | new_symbol->the_bfd = abfd; | |
716 | return new_symbol; | |
717 | } | |
718 | ||
719 | static void | |
720 | wasm_print_symbol (bfd *abfd, | |
07d6d2b8 AM |
721 | void * filep, |
722 | asymbol *symbol, | |
723 | bfd_print_symbol_type how) | |
a6be0538 PC |
724 | { |
725 | FILE *file = (FILE *) filep; | |
726 | ||
727 | switch (how) | |
728 | { | |
729 | case bfd_print_symbol_name: | |
730 | fprintf (file, "%s", symbol->name); | |
731 | break; | |
732 | ||
733 | default: | |
734 | bfd_print_symbol_vandf (abfd, filep, symbol); | |
735 | fprintf (file, " %-5s %s", symbol->section->name, symbol->name); | |
736 | } | |
737 | } | |
738 | ||
739 | static void | |
740 | wasm_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 AM |
741 | asymbol *symbol, |
742 | symbol_info *ret) | |
a6be0538 PC |
743 | { |
744 | bfd_symbol_info (symbol, ret); | |
745 | } | |
746 | ||
747 | /* Check whether ABFD is a WebAssembly module; if so, scan it. */ | |
748 | ||
749 | static const bfd_target * | |
750 | wasm_object_p (bfd *abfd) | |
751 | { | |
752 | bfd_boolean error; | |
753 | ||
754 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
755 | return NULL; | |
756 | ||
757 | if (! wasm_read_header (abfd, &error)) | |
758 | { | |
759 | bfd_set_error (bfd_error_wrong_format); | |
760 | return NULL; | |
761 | } | |
762 | ||
763 | if (! wasm_mkobject (abfd) || ! wasm_scan (abfd)) | |
764 | return NULL; | |
765 | ||
766 | if (! bfd_default_set_arch_mach (abfd, bfd_arch_wasm32, 0)) | |
767 | return NULL; | |
768 | ||
769 | if (wasm_scan_name_function_section (abfd, bfd_get_section_by_name (abfd, WASM_NAME_SECTION))) | |
770 | abfd->flags |= HAS_SYMS; | |
771 | ||
772 | return abfd->xvec; | |
773 | } | |
774 | ||
775 | /* BFD_JUMP_TABLE_WRITE */ | |
07d6d2b8 | 776 | #define wasm_set_arch_mach _bfd_generic_set_arch_mach |
a6be0538 PC |
777 | |
778 | /* BFD_JUMP_TABLE_SYMBOLS */ | |
07d6d2b8 AM |
779 | #define wasm_get_symbol_version_string _bfd_nosymbols_get_symbol_version_string |
780 | #define wasm_bfd_is_local_label_name bfd_generic_is_local_label_name | |
d00dd7dc | 781 | #define wasm_bfd_is_target_special_symbol _bfd_bool_bfd_asymbol_false |
07d6d2b8 AM |
782 | #define wasm_get_lineno _bfd_nosymbols_get_lineno |
783 | #define wasm_find_nearest_line _bfd_nosymbols_find_nearest_line | |
784 | #define wasm_find_line _bfd_nosymbols_find_line | |
785 | #define wasm_find_inliner_info _bfd_nosymbols_find_inliner_info | |
786 | #define wasm_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol | |
787 | #define wasm_read_minisymbols _bfd_generic_read_minisymbols | |
788 | #define wasm_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol | |
a6be0538 PC |
789 | |
790 | const bfd_target wasm_vec = | |
791 | { | |
07d6d2b8 | 792 | "wasm", /* Name. */ |
a6be0538 PC |
793 | bfd_target_unknown_flavour, |
794 | BFD_ENDIAN_LITTLE, | |
795 | BFD_ENDIAN_LITTLE, | |
796 | (HAS_SYMS | WP_TEXT), /* Object flags. */ | |
797 | (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS), /* Section flags. */ | |
07d6d2b8 AM |
798 | 0, /* Leading underscore. */ |
799 | ' ', /* AR_pad_char. */ | |
800 | 255, /* AR_max_namelen. */ | |
a6be0538 PC |
801 | 0, /* Match priority. */ |
802 | /* Routines to byte-swap various sized integers from the data sections. */ | |
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 | /* Routines to byte-swap various sized integers from the file headers. */ | |
808 | bfd_getl64, bfd_getl_signed_64, bfd_putl64, | |
809 | bfd_getl32, bfd_getl_signed_32, bfd_putl32, | |
810 | bfd_getl16, bfd_getl_signed_16, bfd_putl16, | |
811 | ||
812 | { | |
813 | _bfd_dummy_target, | |
814 | wasm_object_p, /* bfd_check_format. */ | |
815 | _bfd_dummy_target, | |
816 | _bfd_dummy_target, | |
817 | }, | |
818 | { | |
d00dd7dc | 819 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
820 | wasm_mkobject, |
821 | _bfd_generic_mkarchive, | |
d00dd7dc | 822 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
823 | }, |
824 | { /* bfd_write_contents. */ | |
d00dd7dc | 825 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
826 | wasm_write_object_contents, |
827 | _bfd_write_archive_contents, | |
d00dd7dc | 828 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
829 | }, |
830 | ||
831 | BFD_JUMP_TABLE_GENERIC (_bfd_generic), | |
832 | BFD_JUMP_TABLE_COPY (_bfd_generic), | |
833 | BFD_JUMP_TABLE_CORE (_bfd_nocore), | |
834 | BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), | |
835 | BFD_JUMP_TABLE_SYMBOLS (wasm), | |
836 | BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), | |
837 | BFD_JUMP_TABLE_WRITE (wasm), | |
838 | BFD_JUMP_TABLE_LINK (_bfd_nolink), | |
839 | BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), | |
840 | ||
841 | NULL, | |
842 | ||
843 | NULL, | |
844 | }; |