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a6be0538 | 1 | /* BFD back-end for WebAssembly modules. |
b3adc24a | 2 | Copyright (C) 2017-2020 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 | ||
a6be0538 PC |
249 | p = asect->contents; |
250 | end = asect->contents + asect->size; | |
251 | ||
0c0adcc5 | 252 | if (!p) |
a6be0538 PC |
253 | return FALSE; |
254 | ||
255 | while (p < end) | |
256 | { | |
257 | bfd_byte subsection_code = *p++; | |
258 | if (subsection_code == WASM_FUNCTION_SUBSECTION) | |
07d6d2b8 | 259 | break; |
a6be0538 PC |
260 | |
261 | /* subsection_code is documented to be a varuint7, meaning that | |
07d6d2b8 AM |
262 | it has to be a single byte in the 0 - 127 range. If it isn't, |
263 | the spec must have changed underneath us, so give up. */ | |
a6be0538 | 264 | if (subsection_code & 0x80) |
07d6d2b8 | 265 | return FALSE; |
a6be0538 PC |
266 | |
267 | READ_LEB128 (payload_size, p, end); | |
268 | ||
0c0adcc5 | 269 | if (payload_size > (size_t) (end - p)) |
07d6d2b8 | 270 | return FALSE; |
a6be0538 PC |
271 | |
272 | p += payload_size; | |
273 | } | |
274 | ||
275 | if (p >= end) | |
276 | return FALSE; | |
277 | ||
278 | READ_LEB128 (payload_size, p, end); | |
279 | ||
0c0adcc5 | 280 | if (payload_size > (size_t) (end - p)) |
a6be0538 PC |
281 | return FALSE; |
282 | ||
283 | end = p + payload_size; | |
284 | ||
285 | READ_LEB128 (symcount, p, end); | |
286 | ||
287 | /* Sanity check: each symbol has at least two bytes. */ | |
0c0adcc5 | 288 | if (symcount > payload_size / 2) |
a6be0538 PC |
289 | return FALSE; |
290 | ||
291 | tdata->symcount = symcount; | |
292 | ||
0c0adcc5 AM |
293 | space_function_index |
294 | = bfd_make_section_with_flags (abfd, WASM_SECTION_FUNCTION_INDEX, | |
295 | SEC_READONLY | SEC_CODE); | |
a6be0538 | 296 | |
0c0adcc5 AM |
297 | if (!space_function_index) |
298 | space_function_index | |
299 | = bfd_get_section_by_name (abfd, WASM_SECTION_FUNCTION_INDEX); | |
a6be0538 | 300 | |
0c0adcc5 | 301 | if (!space_function_index) |
a6be0538 PC |
302 | return FALSE; |
303 | ||
0c0adcc5 AM |
304 | symbols = bfd_alloc2 (abfd, tdata->symcount, sizeof (asymbol)); |
305 | if (!symbols) | |
a6be0538 PC |
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 | ||
0c0adcc5 | 318 | if (len > (size_t) (end - p)) |
07d6d2b8 | 319 | goto error_return; |
a6be0538 | 320 | |
0c0adcc5 AM |
321 | name = bfd_alloc (abfd, len + 1); |
322 | if (!name) | |
07d6d2b8 | 323 | goto error_return; |
a6be0538 PC |
324 | |
325 | memcpy (name, p, len); | |
0c0adcc5 | 326 | name[len] = 0; |
a6be0538 PC |
327 | p += len; |
328 | ||
329 | sym = &symbols[symcount]; | |
330 | sym->the_bfd = abfd; | |
331 | sym->name = name; | |
87993319 | 332 | sym->value = idx; |
a6be0538 PC |
333 | sym->flags = BSF_GLOBAL | BSF_FUNCTION; |
334 | sym->section = space_function_index; | |
335 | sym->udata.p = NULL; | |
336 | } | |
337 | ||
338 | if (symcount < tdata->symcount) | |
339 | goto error_return; | |
340 | ||
341 | tdata->symbols = symbols; | |
342 | abfd->symcount = symcount; | |
343 | ||
344 | return TRUE; | |
345 | ||
346 | error_return: | |
a6be0538 PC |
347 | bfd_release (abfd, symbols); |
348 | return FALSE; | |
349 | } | |
350 | ||
351 | /* Read a byte from ABFD and return it, or EOF for EOF or error. | |
352 | Set ERRORPTR on non-EOF error. */ | |
353 | ||
354 | static int | |
355 | wasm_read_byte (bfd *abfd, bfd_boolean *errorptr) | |
356 | { | |
357 | bfd_byte byte; | |
358 | ||
359 | if (bfd_bread (&byte, (bfd_size_type) 1, abfd) != 1) | |
360 | { | |
361 | if (bfd_get_error () != bfd_error_file_truncated) | |
07d6d2b8 | 362 | *errorptr = TRUE; |
a6be0538 PC |
363 | return EOF; |
364 | } | |
365 | ||
366 | return byte; | |
367 | } | |
368 | ||
369 | /* Scan the wasm module ABFD, creating sections and symbols. | |
370 | Return TRUE on success. */ | |
371 | ||
372 | static bfd_boolean | |
373 | wasm_scan (bfd *abfd) | |
374 | { | |
375 | bfd_boolean error = FALSE; | |
376 | /* Fake VMAs for now. Choose 0x80000000 as base to avoid clashes | |
377 | with actual data addresses. */ | |
378 | bfd_vma vma = 0x80000000; | |
379 | int section_code; | |
380 | unsigned int bytes_read; | |
a6be0538 PC |
381 | asection *bfdsec; |
382 | ||
383 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
384 | goto error_return; | |
385 | ||
0c0adcc5 | 386 | if (!wasm_read_header (abfd, &error)) |
a6be0538 PC |
387 | goto error_return; |
388 | ||
389 | while ((section_code = wasm_read_byte (abfd, &error)) != EOF) | |
390 | { | |
391 | if (section_code != 0) | |
07d6d2b8 AM |
392 | { |
393 | const char *sname = wasm_section_code_to_name (section_code); | |
394 | ||
0c0adcc5 | 395 | if (!sname) |
07d6d2b8 AM |
396 | goto error_return; |
397 | ||
0c0adcc5 AM |
398 | bfdsec = bfd_make_section_anyway_with_flags (abfd, sname, |
399 | SEC_HAS_CONTENTS); | |
07d6d2b8 AM |
400 | if (bfdsec == NULL) |
401 | goto error_return; | |
07d6d2b8 AM |
402 | |
403 | bfdsec->vma = vma; | |
404 | bfdsec->lma = vma; | |
405 | bfdsec->size = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
406 | if (error) | |
407 | goto error_return; | |
408 | bfdsec->filepos = bfd_tell (abfd); | |
409 | bfdsec->alignment_power = 0; | |
410 | } | |
a6be0538 | 411 | else |
07d6d2b8 AM |
412 | { |
413 | bfd_vma payload_len; | |
414 | file_ptr section_start; | |
415 | bfd_vma namelen; | |
0c0adcc5 | 416 | char *name; |
07d6d2b8 | 417 | char *prefix = WASM_SECTION_PREFIX; |
0c0adcc5 | 418 | size_t prefixlen = strlen (prefix); |
07d6d2b8 AM |
419 | |
420 | payload_len = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
421 | if (error) | |
422 | goto error_return; | |
423 | section_start = bfd_tell (abfd); | |
424 | namelen = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
425 | if (error || namelen > payload_len) | |
426 | goto error_return; | |
0c0adcc5 AM |
427 | name = bfd_alloc (abfd, namelen + prefixlen + 1); |
428 | if (!name) | |
07d6d2b8 | 429 | goto error_return; |
0c0adcc5 AM |
430 | memcpy (name, prefix, prefixlen); |
431 | if (bfd_bread (name + prefixlen, namelen, abfd) != namelen) | |
a6be0538 | 432 | goto error_return; |
0c0adcc5 | 433 | name[prefixlen + namelen] = 0; |
a6be0538 | 434 | |
0c0adcc5 AM |
435 | bfdsec = bfd_make_section_anyway_with_flags (abfd, name, |
436 | SEC_HAS_CONTENTS); | |
07d6d2b8 AM |
437 | if (bfdsec == NULL) |
438 | goto error_return; | |
a6be0538 | 439 | |
07d6d2b8 AM |
440 | bfdsec->vma = vma; |
441 | bfdsec->lma = vma; | |
442 | bfdsec->filepos = bfd_tell (abfd); | |
443 | bfdsec->size = section_start + payload_len - bfdsec->filepos; | |
444 | bfdsec->alignment_power = 0; | |
445 | } | |
a6be0538 PC |
446 | |
447 | if (bfdsec->size != 0) | |
07d6d2b8 | 448 | { |
0c0adcc5 AM |
449 | bfdsec->contents = bfd_alloc (abfd, bfdsec->size); |
450 | if (!bfdsec->contents) | |
07d6d2b8 | 451 | goto error_return; |
a6be0538 | 452 | |
07d6d2b8 | 453 | if (bfd_bread (bfdsec->contents, bfdsec->size, abfd) != bfdsec->size) |
a6be0538 | 454 | goto error_return; |
07d6d2b8 | 455 | } |
a6be0538 PC |
456 | |
457 | vma += bfdsec->size; | |
458 | } | |
459 | ||
460 | /* Make sure we're at actual EOF. There's no indication in the | |
461 | WebAssembly format of how long the file is supposed to be. */ | |
462 | if (error) | |
463 | goto error_return; | |
464 | ||
465 | return TRUE; | |
466 | ||
467 | error_return: | |
a6be0538 PC |
468 | return FALSE; |
469 | } | |
470 | ||
471 | /* Put a numbered section ASECT of ABFD into the table of numbered | |
472 | sections pointed to by FSARG. */ | |
473 | ||
474 | static void | |
475 | wasm_register_section (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 | 476 | asection *asect, |
a6be0538 PC |
477 | void *fsarg) |
478 | { | |
479 | sec_ptr *numbered_sections = fsarg; | |
87993319 | 480 | int idx = wasm_section_name_to_code (asect->name); |
a6be0538 | 481 | |
87993319 | 482 | if (idx == 0) |
a6be0538 PC |
483 | return; |
484 | ||
87993319 | 485 | numbered_sections[idx] = asect; |
a6be0538 PC |
486 | } |
487 | ||
488 | struct compute_section_arg | |
489 | { | |
490 | bfd_vma pos; | |
491 | bfd_boolean failed; | |
492 | }; | |
493 | ||
494 | /* Compute the file position of ABFD's section ASECT. FSARG is a | |
495 | pointer to the current file position. | |
496 | ||
497 | We allow section names of the form .wasm.id to encode the numbered | |
498 | section with ID id, if it exists; otherwise, a custom section with | |
499 | ID "id" is produced. Arbitrary section names are for sections that | |
500 | are assumed already to contain a section header; those are appended | |
501 | to the WebAssembly module verbatim. */ | |
502 | ||
503 | static void | |
504 | wasm_compute_custom_section_file_position (bfd *abfd, | |
505 | sec_ptr asect, | |
07d6d2b8 | 506 | void *fsarg) |
a6be0538 PC |
507 | { |
508 | struct compute_section_arg *fs = fsarg; | |
87993319 | 509 | int idx; |
a6be0538 PC |
510 | |
511 | if (fs->failed) | |
512 | return; | |
513 | ||
87993319 | 514 | idx = wasm_section_name_to_code (asect->name); |
a6be0538 | 515 | |
87993319 | 516 | if (idx != 0) |
a6be0538 PC |
517 | return; |
518 | ||
519 | if (CONST_STRNEQ (asect->name, WASM_SECTION_PREFIX)) | |
520 | { | |
521 | const char *name = asect->name + strlen (WASM_SECTION_PREFIX); | |
522 | bfd_size_type payload_len = asect->size; | |
523 | bfd_size_type name_len = strlen (name); | |
524 | bfd_size_type nl = name_len; | |
525 | ||
526 | payload_len += name_len; | |
527 | ||
528 | do | |
07d6d2b8 AM |
529 | { |
530 | payload_len++; | |
531 | nl >>= 7; | |
532 | } | |
a6be0538 PC |
533 | while (nl); |
534 | ||
535 | bfd_seek (abfd, fs->pos, SEEK_SET); | |
536 | if (! wasm_write_uleb128 (abfd, 0) | |
07d6d2b8 AM |
537 | || ! wasm_write_uleb128 (abfd, payload_len) |
538 | || ! wasm_write_uleb128 (abfd, name_len) | |
539 | || bfd_bwrite (name, name_len, abfd) != name_len) | |
540 | goto error_return; | |
a6be0538 PC |
541 | fs->pos = asect->filepos = bfd_tell (abfd); |
542 | } | |
543 | else | |
544 | { | |
545 | asect->filepos = fs->pos; | |
546 | } | |
547 | ||
548 | ||
549 | fs->pos += asect->size; | |
550 | return; | |
551 | ||
552 | error_return: | |
553 | fs->failed = TRUE; | |
554 | } | |
555 | ||
556 | /* Compute the file positions for the sections of ABFD. Currently, | |
557 | this writes all numbered sections first, in order, then all custom | |
558 | sections, in section order. | |
559 | ||
560 | The spec says that the numbered sections must appear in order of | |
561 | their ids, but custom sections can appear in any position and any | |
562 | order, and more than once. FIXME: support that. */ | |
563 | ||
564 | static bfd_boolean | |
565 | wasm_compute_section_file_positions (bfd *abfd) | |
566 | { | |
567 | bfd_byte magic[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
568 | bfd_byte vers[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
569 | sec_ptr numbered_sections[WASM_NUMBERED_SECTIONS]; | |
570 | struct compute_section_arg fs; | |
571 | unsigned int i; | |
572 | ||
573 | bfd_seek (abfd, (bfd_vma) 0, SEEK_SET); | |
574 | ||
575 | if (bfd_bwrite (magic, sizeof (magic), abfd) != (sizeof magic) | |
576 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
577 | return FALSE; | |
578 | ||
579 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
580 | numbered_sections[i] = NULL; | |
581 | ||
582 | bfd_map_over_sections (abfd, wasm_register_section, numbered_sections); | |
583 | ||
584 | fs.pos = bfd_tell (abfd); | |
585 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
586 | { | |
587 | sec_ptr sec = numbered_sections[i]; | |
588 | bfd_size_type size; | |
589 | ||
590 | if (! sec) | |
07d6d2b8 | 591 | continue; |
a6be0538 PC |
592 | size = sec->size; |
593 | if (bfd_seek (abfd, fs.pos, SEEK_SET) != 0) | |
07d6d2b8 | 594 | return FALSE; |
a6be0538 | 595 | if (! wasm_write_uleb128 (abfd, i) |
07d6d2b8 AM |
596 | || ! wasm_write_uleb128 (abfd, size)) |
597 | return FALSE; | |
a6be0538 PC |
598 | fs.pos = sec->filepos = bfd_tell (abfd); |
599 | fs.pos += size; | |
600 | } | |
601 | ||
602 | fs.failed = FALSE; | |
603 | ||
604 | bfd_map_over_sections (abfd, wasm_compute_custom_section_file_position, &fs); | |
605 | ||
606 | if (fs.failed) | |
607 | return FALSE; | |
608 | ||
609 | abfd->output_has_begun = TRUE; | |
610 | ||
611 | return TRUE; | |
612 | } | |
613 | ||
614 | static bfd_boolean | |
615 | wasm_set_section_contents (bfd *abfd, | |
07d6d2b8 AM |
616 | sec_ptr section, |
617 | const void *location, | |
618 | file_ptr offset, | |
619 | bfd_size_type count) | |
a6be0538 PC |
620 | { |
621 | if (count == 0) | |
622 | return TRUE; | |
623 | ||
624 | if (! abfd->output_has_begun | |
625 | && ! wasm_compute_section_file_positions (abfd)) | |
626 | return FALSE; | |
627 | ||
628 | if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 | |
629 | || bfd_bwrite (location, count, abfd) != count) | |
630 | return FALSE; | |
631 | ||
632 | return TRUE; | |
633 | } | |
634 | ||
635 | static bfd_boolean | |
636 | wasm_write_object_contents (bfd* abfd) | |
637 | { | |
638 | bfd_byte magic[] = WASM_MAGIC; | |
639 | bfd_byte vers[] = WASM_VERSION; | |
640 | ||
641 | if (bfd_seek (abfd, 0, SEEK_SET) != 0) | |
642 | return FALSE; | |
643 | ||
644 | if (bfd_bwrite (magic, sizeof (magic), abfd) != sizeof (magic) | |
645 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
646 | return FALSE; | |
647 | ||
648 | return TRUE; | |
649 | } | |
650 | ||
651 | static bfd_boolean | |
652 | wasm_mkobject (bfd *abfd) | |
653 | { | |
654 | tdata_type *tdata = (tdata_type *) bfd_alloc (abfd, sizeof (tdata_type)); | |
655 | ||
656 | if (! tdata) | |
657 | return FALSE; | |
658 | ||
659 | tdata->symbols = NULL; | |
660 | tdata->symcount = 0; | |
661 | ||
662 | abfd->tdata.any = tdata; | |
663 | ||
664 | return TRUE; | |
665 | } | |
666 | ||
667 | static long | |
668 | wasm_get_symtab_upper_bound (bfd *abfd) | |
669 | { | |
670 | tdata_type *tdata = abfd->tdata.any; | |
671 | ||
672 | return (tdata->symcount + 1) * (sizeof (asymbol *)); | |
673 | } | |
674 | ||
675 | static long | |
676 | wasm_canonicalize_symtab (bfd *abfd, asymbol **alocation) | |
677 | { | |
678 | tdata_type *tdata = abfd->tdata.any; | |
679 | size_t i; | |
680 | ||
681 | for (i = 0; i < tdata->symcount; i++) | |
682 | alocation[i] = &tdata->symbols[i]; | |
683 | alocation[i] = NULL; | |
684 | ||
685 | return tdata->symcount; | |
686 | } | |
687 | ||
688 | static asymbol * | |
689 | wasm_make_empty_symbol (bfd *abfd) | |
690 | { | |
986f0783 | 691 | size_t amt = sizeof (asymbol); |
a6be0538 PC |
692 | asymbol *new_symbol = (asymbol *) bfd_zalloc (abfd, amt); |
693 | ||
694 | if (! new_symbol) | |
695 | return NULL; | |
696 | new_symbol->the_bfd = abfd; | |
697 | return new_symbol; | |
698 | } | |
699 | ||
700 | static void | |
701 | wasm_print_symbol (bfd *abfd, | |
07d6d2b8 AM |
702 | void * filep, |
703 | asymbol *symbol, | |
704 | bfd_print_symbol_type how) | |
a6be0538 PC |
705 | { |
706 | FILE *file = (FILE *) filep; | |
707 | ||
708 | switch (how) | |
709 | { | |
710 | case bfd_print_symbol_name: | |
711 | fprintf (file, "%s", symbol->name); | |
712 | break; | |
713 | ||
714 | default: | |
715 | bfd_print_symbol_vandf (abfd, filep, symbol); | |
716 | fprintf (file, " %-5s %s", symbol->section->name, symbol->name); | |
717 | } | |
718 | } | |
719 | ||
720 | static void | |
721 | wasm_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 AM |
722 | asymbol *symbol, |
723 | symbol_info *ret) | |
a6be0538 PC |
724 | { |
725 | bfd_symbol_info (symbol, ret); | |
726 | } | |
727 | ||
728 | /* Check whether ABFD is a WebAssembly module; if so, scan it. */ | |
729 | ||
730 | static const bfd_target * | |
731 | wasm_object_p (bfd *abfd) | |
732 | { | |
733 | bfd_boolean error; | |
0c0adcc5 | 734 | asection *s; |
a6be0538 PC |
735 | |
736 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
737 | return NULL; | |
738 | ||
0c0adcc5 | 739 | if (!wasm_read_header (abfd, &error)) |
a6be0538 PC |
740 | { |
741 | bfd_set_error (bfd_error_wrong_format); | |
742 | return NULL; | |
743 | } | |
744 | ||
0c0adcc5 | 745 | if (!wasm_mkobject (abfd)) |
a6be0538 PC |
746 | return NULL; |
747 | ||
0c0adcc5 AM |
748 | if (!wasm_scan (abfd) |
749 | || !bfd_default_set_arch_mach (abfd, bfd_arch_wasm32, 0)) | |
750 | { | |
751 | bfd_release (abfd, abfd->tdata.any); | |
752 | abfd->tdata.any = NULL; | |
753 | return NULL; | |
754 | } | |
a6be0538 | 755 | |
0c0adcc5 AM |
756 | s = bfd_get_section_by_name (abfd, WASM_NAME_SECTION); |
757 | if (s != NULL && wasm_scan_name_function_section (abfd, s)) | |
a6be0538 PC |
758 | abfd->flags |= HAS_SYMS; |
759 | ||
760 | return abfd->xvec; | |
761 | } | |
762 | ||
763 | /* BFD_JUMP_TABLE_WRITE */ | |
07d6d2b8 | 764 | #define wasm_set_arch_mach _bfd_generic_set_arch_mach |
a6be0538 PC |
765 | |
766 | /* BFD_JUMP_TABLE_SYMBOLS */ | |
07d6d2b8 AM |
767 | #define wasm_get_symbol_version_string _bfd_nosymbols_get_symbol_version_string |
768 | #define wasm_bfd_is_local_label_name bfd_generic_is_local_label_name | |
d00dd7dc | 769 | #define wasm_bfd_is_target_special_symbol _bfd_bool_bfd_asymbol_false |
07d6d2b8 AM |
770 | #define wasm_get_lineno _bfd_nosymbols_get_lineno |
771 | #define wasm_find_nearest_line _bfd_nosymbols_find_nearest_line | |
772 | #define wasm_find_line _bfd_nosymbols_find_line | |
773 | #define wasm_find_inliner_info _bfd_nosymbols_find_inliner_info | |
774 | #define wasm_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol | |
775 | #define wasm_read_minisymbols _bfd_generic_read_minisymbols | |
776 | #define wasm_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol | |
a6be0538 PC |
777 | |
778 | const bfd_target wasm_vec = | |
779 | { | |
07d6d2b8 | 780 | "wasm", /* Name. */ |
a6be0538 PC |
781 | bfd_target_unknown_flavour, |
782 | BFD_ENDIAN_LITTLE, | |
783 | BFD_ENDIAN_LITTLE, | |
784 | (HAS_SYMS | WP_TEXT), /* Object flags. */ | |
785 | (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS), /* Section flags. */ | |
07d6d2b8 AM |
786 | 0, /* Leading underscore. */ |
787 | ' ', /* AR_pad_char. */ | |
788 | 255, /* AR_max_namelen. */ | |
a6be0538 PC |
789 | 0, /* Match priority. */ |
790 | /* Routines to byte-swap various sized integers from the data sections. */ | |
791 | bfd_getl64, bfd_getl_signed_64, bfd_putl64, | |
792 | bfd_getl32, bfd_getl_signed_32, bfd_putl32, | |
793 | bfd_getl16, bfd_getl_signed_16, bfd_putl16, | |
794 | ||
795 | /* Routines to byte-swap various sized integers from the file headers. */ | |
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 | { | |
801 | _bfd_dummy_target, | |
802 | wasm_object_p, /* bfd_check_format. */ | |
803 | _bfd_dummy_target, | |
804 | _bfd_dummy_target, | |
805 | }, | |
806 | { | |
d00dd7dc | 807 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
808 | wasm_mkobject, |
809 | _bfd_generic_mkarchive, | |
d00dd7dc | 810 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
811 | }, |
812 | { /* bfd_write_contents. */ | |
d00dd7dc | 813 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
814 | wasm_write_object_contents, |
815 | _bfd_write_archive_contents, | |
d00dd7dc | 816 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
817 | }, |
818 | ||
819 | BFD_JUMP_TABLE_GENERIC (_bfd_generic), | |
820 | BFD_JUMP_TABLE_COPY (_bfd_generic), | |
821 | BFD_JUMP_TABLE_CORE (_bfd_nocore), | |
822 | BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), | |
823 | BFD_JUMP_TABLE_SYMBOLS (wasm), | |
824 | BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), | |
825 | BFD_JUMP_TABLE_WRITE (wasm), | |
826 | BFD_JUMP_TABLE_LINK (_bfd_nolink), | |
827 | BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), | |
828 | ||
829 | NULL, | |
830 | ||
831 | NULL, | |
832 | }; |