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[deliverable/binutils-gdb.git] / bfd / wasm-module.c
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a6be0538 1/* BFD back-end for WebAssembly modules.
250d07de 2 Copyright (C) 2017-2021 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"
a6be0538 29#include "bfd.h"
a6be0538
PC
30#include "libiberty.h"
31#include "libbfd.h"
32#include "wasm-module.h"
33
b9b204b3 34#include <limits.h>
b9b204b3
AM
35#ifndef CHAR_BIT
36#define CHAR_BIT 8
37#endif
38
a6be0538
PC
39typedef struct
40{
41 asymbol * symbols;
42 bfd_size_type symcount;
43} tdata_type;
44
45static const char * const wasm_numbered_sections[] =
46{
47 NULL, /* Custom section, different layout. */
48 WASM_SECTION ( 1, "type"),
49 WASM_SECTION ( 2, "import"),
50 WASM_SECTION ( 3, "function"),
51 WASM_SECTION ( 4, "table"),
52 WASM_SECTION ( 5, "memory"),
53 WASM_SECTION ( 6, "global"),
54 WASM_SECTION ( 7, "export"),
55 WASM_SECTION ( 8, "start"),
56 WASM_SECTION ( 9, "element"),
57 WASM_SECTION (10, "code"),
58 WASM_SECTION (11, "data"),
59};
60
61#define WASM_NUMBERED_SECTIONS ARRAY_SIZE (wasm_numbered_sections)
62
63/* Resolve SECTION_CODE to a section name if there is one, NULL
64 otherwise. */
65
66static const char *
67wasm_section_code_to_name (bfd_byte section_code)
68{
69 if (section_code < WASM_NUMBERED_SECTIONS)
70 return wasm_numbered_sections[section_code];
71
72 return NULL;
73}
74
75/* Translate section name NAME to a section code, or 0 if it's a
76 custom name. */
77
78static unsigned int
79wasm_section_name_to_code (const char *name)
80{
81 unsigned i;
82
83 for (i = 1; i < WASM_NUMBERED_SECTIONS; i++)
84 if (strcmp (name, wasm_numbered_sections[i]) == 0)
85 return i;
86
87 return 0;
88}
89
90/* WebAssembly LEB128 integers are sufficiently like DWARF LEB128
91 integers that we use _bfd_safe_read_leb128, but there are two
92 points of difference:
93
94 - WebAssembly requires a 32-bit value to be encoded in at most 5
95 bytes, etc.
96 - _bfd_safe_read_leb128 accepts incomplete LEB128 encodings at the
97 end of the buffer, while these are invalid in WebAssembly.
98
99 Those differences mean that we will accept some files that are
100 invalid WebAssembly. */
101
102/* Read an LEB128-encoded integer from ABFD's I/O stream, reading one
103 byte at a time. Set ERROR_RETURN if no complete integer could be
104 read, LENGTH_RETURN to the number of bytes read (including bytes in
105 incomplete numbers). SIGN means interpret the number as SLEB128. */
106
107static bfd_vma
0a1b45a2
AM
108wasm_read_leb128 (bfd *abfd,
109 bool *error_return,
110 unsigned int *length_return,
111 bool sign)
a6be0538
PC
112{
113 bfd_vma result = 0;
114 unsigned int num_read = 0;
115 unsigned int shift = 0;
116 unsigned char byte = 0;
b9b204b3 117 unsigned char lost, mask;
27c1c427 118 int status = 1;
a6be0538
PC
119
120 while (bfd_bread (&byte, 1, abfd) == 1)
121 {
122 num_read++;
123
b9b204b3 124 if (shift < CHAR_BIT * sizeof (result))
27c1c427
AM
125 {
126 result |= ((bfd_vma) (byte & 0x7f)) << shift;
b9b204b3
AM
127 /* These bits overflowed. */
128 lost = byte ^ (result >> shift);
129 /* And this is the mask of possible overflow bits. */
130 mask = 0x7f ^ ((bfd_vma) 0x7f << shift >> shift);
27c1c427
AM
131 shift += 7;
132 }
b9b204b3
AM
133 else
134 {
135 lost = byte;
136 mask = 0x7f;
137 }
138 if ((lost & mask) != (sign && (bfd_signed_vma) result < 0 ? mask : 0))
27c1c427 139 status |= 2;
a6be0538 140
a6be0538 141 if ((byte & 0x80) == 0)
07d6d2b8 142 {
27c1c427 143 status &= ~1;
b9b204b3 144 if (sign && shift < CHAR_BIT * sizeof (result) && (byte & 0x40))
27c1c427 145 result |= -((bfd_vma) 1 << shift);
07d6d2b8
AM
146 break;
147 }
a6be0538
PC
148 }
149
150 if (length_return != NULL)
151 *length_return = num_read;
152 if (error_return != NULL)
27c1c427 153 *error_return = status != 0;
a6be0538
PC
154
155 return result;
156}
157
158/* Encode an integer V as LEB128 and write it to ABFD, return TRUE on
159 success. */
160
0a1b45a2 161static bool
a6be0538
PC
162wasm_write_uleb128 (bfd *abfd, bfd_vma v)
163{
164 do
165 {
166 bfd_byte c = v & 0x7f;
167 v >>= 7;
168
169 if (v)
07d6d2b8 170 c |= 0x80;
a6be0538
PC
171
172 if (bfd_bwrite (&c, 1, abfd) != 1)
0a1b45a2 173 return false;
a6be0538
PC
174 }
175 while (v);
176
0a1b45a2 177 return true;
a6be0538
PC
178}
179
180/* Read the LEB128 integer at P, saving it to X; at end of buffer,
181 jump to error_return. */
07d6d2b8
AM
182#define READ_LEB128(x, p, end) \
183 do \
184 { \
574ec108 185 if ((p) >= (end)) \
07d6d2b8 186 goto error_return; \
574ec108 187 (x) = _bfd_safe_read_leb128 (abfd, &(p), false, (end)); \
07d6d2b8 188 } \
a6be0538
PC
189 while (0)
190
191/* Verify the magic number at the beginning of a WebAssembly module
192 ABFD, setting ERRORPTR if there's a mismatch. */
193
0a1b45a2
AM
194static bool
195wasm_read_magic (bfd *abfd, bool *errorptr)
a6be0538
PC
196{
197 bfd_byte magic_const[SIZEOF_WASM_MAGIC] = WASM_MAGIC;
198 bfd_byte magic[SIZEOF_WASM_MAGIC];
199
200 if (bfd_bread (magic, sizeof (magic), abfd) == sizeof (magic)
201 && memcmp (magic, magic_const, sizeof (magic)) == 0)
0a1b45a2 202 return true;
a6be0538 203
0a1b45a2
AM
204 *errorptr = true;
205 return false;
a6be0538
PC
206}
207
208/* Read the version number from ABFD, returning TRUE if it's a supported
209 version. Set ERRORPTR otherwise. */
210
0a1b45a2
AM
211static bool
212wasm_read_version (bfd *abfd, bool *errorptr)
a6be0538
PC
213{
214 bfd_byte vers_const[SIZEOF_WASM_VERSION] = WASM_VERSION;
215 bfd_byte vers[SIZEOF_WASM_VERSION];
216
217 if (bfd_bread (vers, sizeof (vers), abfd) == sizeof (vers)
218 /* Don't attempt to parse newer versions, which are likely to
219 require code changes. */
220 && memcmp (vers, vers_const, sizeof (vers)) == 0)
0a1b45a2 221 return true;
a6be0538 222
0a1b45a2
AM
223 *errorptr = true;
224 return false;
a6be0538
PC
225}
226
227/* Read the WebAssembly header (magic number plus version number) from
228 ABFD, setting ERRORPTR to TRUE if there is a mismatch. */
229
0a1b45a2
AM
230static bool
231wasm_read_header (bfd *abfd, bool *errorptr)
a6be0538
PC
232{
233 if (! wasm_read_magic (abfd, errorptr))
0a1b45a2 234 return false;
a6be0538
PC
235
236 if (! wasm_read_version (abfd, errorptr))
0a1b45a2 237 return false;
a6be0538 238
0a1b45a2 239 return true;
a6be0538
PC
240}
241
242/* Scan the "function" subsection of the "name" section ASECT in the
243 wasm module ABFD. Create symbols. Return TRUE on success. */
244
0a1b45a2 245static bool
a6be0538
PC
246wasm_scan_name_function_section (bfd *abfd, sec_ptr asect)
247{
248 bfd_byte *p;
249 bfd_byte *end;
250 bfd_vma payload_size;
251 bfd_vma symcount = 0;
252 tdata_type *tdata = abfd->tdata.any;
253 asymbol *symbols = NULL;
254 sec_ptr space_function_index;
1f4361a7 255 size_t amt;
a6be0538 256
a6be0538
PC
257 p = asect->contents;
258 end = asect->contents + asect->size;
259
0c0adcc5 260 if (!p)
0a1b45a2 261 return false;
a6be0538
PC
262
263 while (p < end)
264 {
265 bfd_byte subsection_code = *p++;
266 if (subsection_code == WASM_FUNCTION_SUBSECTION)
07d6d2b8 267 break;
a6be0538
PC
268
269 /* subsection_code is documented to be a varuint7, meaning that
07d6d2b8
AM
270 it has to be a single byte in the 0 - 127 range. If it isn't,
271 the spec must have changed underneath us, so give up. */
a6be0538 272 if (subsection_code & 0x80)
0a1b45a2 273 return false;
a6be0538
PC
274
275 READ_LEB128 (payload_size, p, end);
276
0c0adcc5 277 if (payload_size > (size_t) (end - p))
0a1b45a2 278 return false;
a6be0538
PC
279
280 p += payload_size;
281 }
282
283 if (p >= end)
0a1b45a2 284 return false;
a6be0538
PC
285
286 READ_LEB128 (payload_size, p, end);
287
0c0adcc5 288 if (payload_size > (size_t) (end - p))
0a1b45a2 289 return false;
a6be0538
PC
290
291 end = p + payload_size;
292
293 READ_LEB128 (symcount, p, end);
294
295 /* Sanity check: each symbol has at least two bytes. */
0c0adcc5 296 if (symcount > payload_size / 2)
0a1b45a2 297 return false;
a6be0538
PC
298
299 tdata->symcount = symcount;
300
0c0adcc5
AM
301 space_function_index
302 = bfd_make_section_with_flags (abfd, WASM_SECTION_FUNCTION_INDEX,
303 SEC_READONLY | SEC_CODE);
a6be0538 304
0c0adcc5
AM
305 if (!space_function_index)
306 space_function_index
307 = bfd_get_section_by_name (abfd, WASM_SECTION_FUNCTION_INDEX);
a6be0538 308
0c0adcc5 309 if (!space_function_index)
0a1b45a2 310 return false;
a6be0538 311
1f4361a7
AM
312 if (_bfd_mul_overflow (tdata->symcount, sizeof (asymbol), &amt))
313 {
314 bfd_set_error (bfd_error_file_too_big);
0a1b45a2 315 return false;
1f4361a7
AM
316 }
317 symbols = bfd_alloc (abfd, amt);
0c0adcc5 318 if (!symbols)
0a1b45a2 319 return false;
a6be0538
PC
320
321 for (symcount = 0; p < end && symcount < tdata->symcount; symcount++)
322 {
87993319 323 bfd_vma idx;
a6be0538
PC
324 bfd_vma len;
325 char *name;
326 asymbol *sym;
327
87993319 328 READ_LEB128 (idx, p, end);
a6be0538
PC
329 READ_LEB128 (len, p, end);
330
0c0adcc5 331 if (len > (size_t) (end - p))
07d6d2b8 332 goto error_return;
a6be0538 333
0c0adcc5
AM
334 name = bfd_alloc (abfd, len + 1);
335 if (!name)
07d6d2b8 336 goto error_return;
a6be0538
PC
337
338 memcpy (name, p, len);
0c0adcc5 339 name[len] = 0;
a6be0538
PC
340 p += len;
341
342 sym = &symbols[symcount];
343 sym->the_bfd = abfd;
344 sym->name = name;
87993319 345 sym->value = idx;
a6be0538
PC
346 sym->flags = BSF_GLOBAL | BSF_FUNCTION;
347 sym->section = space_function_index;
348 sym->udata.p = NULL;
349 }
350
351 if (symcount < tdata->symcount)
352 goto error_return;
353
354 tdata->symbols = symbols;
355 abfd->symcount = symcount;
356
0a1b45a2 357 return true;
a6be0538
PC
358
359 error_return:
a6be0538 360 bfd_release (abfd, symbols);
0a1b45a2 361 return false;
a6be0538
PC
362}
363
364/* Read a byte from ABFD and return it, or EOF for EOF or error.
365 Set ERRORPTR on non-EOF error. */
366
367static int
0a1b45a2 368wasm_read_byte (bfd *abfd, bool *errorptr)
a6be0538
PC
369{
370 bfd_byte byte;
371
372 if (bfd_bread (&byte, (bfd_size_type) 1, abfd) != 1)
373 {
374 if (bfd_get_error () != bfd_error_file_truncated)
0a1b45a2 375 *errorptr = true;
a6be0538
PC
376 return EOF;
377 }
378
379 return byte;
380}
381
382/* Scan the wasm module ABFD, creating sections and symbols.
383 Return TRUE on success. */
384
0a1b45a2 385static bool
a6be0538
PC
386wasm_scan (bfd *abfd)
387{
0a1b45a2 388 bool error = false;
a6be0538
PC
389 /* Fake VMAs for now. Choose 0x80000000 as base to avoid clashes
390 with actual data addresses. */
391 bfd_vma vma = 0x80000000;
392 int section_code;
393 unsigned int bytes_read;
a6be0538
PC
394 asection *bfdsec;
395
396 if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
397 goto error_return;
398
0c0adcc5 399 if (!wasm_read_header (abfd, &error))
a6be0538
PC
400 goto error_return;
401
402 while ((section_code = wasm_read_byte (abfd, &error)) != EOF)
403 {
404 if (section_code != 0)
07d6d2b8
AM
405 {
406 const char *sname = wasm_section_code_to_name (section_code);
407
0c0adcc5 408 if (!sname)
07d6d2b8
AM
409 goto error_return;
410
0c0adcc5
AM
411 bfdsec = bfd_make_section_anyway_with_flags (abfd, sname,
412 SEC_HAS_CONTENTS);
07d6d2b8
AM
413 if (bfdsec == NULL)
414 goto error_return;
07d6d2b8 415
0a1b45a2 416 bfdsec->size = wasm_read_leb128 (abfd, &error, &bytes_read, false);
07d6d2b8
AM
417 if (error)
418 goto error_return;
07d6d2b8 419 }
a6be0538 420 else
07d6d2b8
AM
421 {
422 bfd_vma payload_len;
07d6d2b8 423 bfd_vma namelen;
0c0adcc5 424 char *name;
07d6d2b8 425 char *prefix = WASM_SECTION_PREFIX;
0c0adcc5 426 size_t prefixlen = strlen (prefix);
2f57795b 427 ufile_ptr filesize;
07d6d2b8 428
0a1b45a2 429 payload_len = wasm_read_leb128 (abfd, &error, &bytes_read, false);
07d6d2b8
AM
430 if (error)
431 goto error_return;
0a1b45a2 432 namelen = wasm_read_leb128 (abfd, &error, &bytes_read, false);
2f57795b
AM
433 if (error || bytes_read > payload_len
434 || namelen > payload_len - bytes_read)
07d6d2b8 435 goto error_return;
2f57795b
AM
436 payload_len -= namelen + bytes_read;
437 filesize = bfd_get_file_size (abfd);
438 if (filesize != 0 && namelen > filesize)
439 {
440 bfd_set_error (bfd_error_file_truncated);
0a1b45a2 441 return false;
2f57795b 442 }
0c0adcc5
AM
443 name = bfd_alloc (abfd, namelen + prefixlen + 1);
444 if (!name)
07d6d2b8 445 goto error_return;
0c0adcc5
AM
446 memcpy (name, prefix, prefixlen);
447 if (bfd_bread (name + prefixlen, namelen, abfd) != namelen)
a6be0538 448 goto error_return;
0c0adcc5 449 name[prefixlen + namelen] = 0;
a6be0538 450
0c0adcc5
AM
451 bfdsec = bfd_make_section_anyway_with_flags (abfd, name,
452 SEC_HAS_CONTENTS);
07d6d2b8
AM
453 if (bfdsec == NULL)
454 goto error_return;
a6be0538 455
2f57795b 456 bfdsec->size = payload_len;
07d6d2b8 457 }
a6be0538 458
2f57795b
AM
459 bfdsec->vma = vma;
460 bfdsec->lma = vma;
461 bfdsec->alignment_power = 0;
462 bfdsec->filepos = bfd_tell (abfd);
a6be0538 463 if (bfdsec->size != 0)
07d6d2b8 464 {
2bb3687b
AM
465 bfdsec->contents = _bfd_alloc_and_read (abfd, bfdsec->size,
466 bfdsec->size);
0c0adcc5 467 if (!bfdsec->contents)
07d6d2b8 468 goto error_return;
07d6d2b8 469 }
a6be0538
PC
470
471 vma += bfdsec->size;
472 }
473
474 /* Make sure we're at actual EOF. There's no indication in the
475 WebAssembly format of how long the file is supposed to be. */
476 if (error)
477 goto error_return;
478
0a1b45a2 479 return true;
a6be0538
PC
480
481 error_return:
0a1b45a2 482 return false;
a6be0538
PC
483}
484
485/* Put a numbered section ASECT of ABFD into the table of numbered
486 sections pointed to by FSARG. */
487
488static void
489wasm_register_section (bfd *abfd ATTRIBUTE_UNUSED,
07d6d2b8 490 asection *asect,
a6be0538
PC
491 void *fsarg)
492{
493 sec_ptr *numbered_sections = fsarg;
87993319 494 int idx = wasm_section_name_to_code (asect->name);
a6be0538 495
87993319 496 if (idx == 0)
a6be0538
PC
497 return;
498
87993319 499 numbered_sections[idx] = asect;
a6be0538
PC
500}
501
502struct compute_section_arg
503{
504 bfd_vma pos;
0a1b45a2 505 bool failed;
a6be0538
PC
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
517static void
518wasm_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;
87993319 523 int idx;
a6be0538
PC
524
525 if (fs->failed)
526 return;
527
87993319 528 idx = wasm_section_name_to_code (asect->name);
a6be0538 529
87993319 530 if (idx != 0)
a6be0538
PC
531 return;
532
08dedd66 533 if (startswith (asect->name, WASM_SECTION_PREFIX))
a6be0538
PC
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:
0a1b45a2 567 fs->failed = true;
a6be0538
PC
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
0a1b45a2 578static bool
a6be0538
PC
579wasm_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))
0a1b45a2 591 return false;
a6be0538
PC
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)
0a1b45a2 608 return false;
a6be0538 609 if (! wasm_write_uleb128 (abfd, i)
07d6d2b8 610 || ! wasm_write_uleb128 (abfd, size))
0a1b45a2 611 return false;
a6be0538
PC
612 fs.pos = sec->filepos = bfd_tell (abfd);
613 fs.pos += size;
614 }
615
0a1b45a2 616 fs.failed = false;
a6be0538
PC
617
618 bfd_map_over_sections (abfd, wasm_compute_custom_section_file_position, &fs);
619
620 if (fs.failed)
0a1b45a2 621 return false;
a6be0538 622
0a1b45a2 623 abfd->output_has_begun = true;
a6be0538 624
0a1b45a2 625 return true;
a6be0538
PC
626}
627
0a1b45a2 628static bool
a6be0538 629wasm_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)
0a1b45a2 636 return true;
a6be0538
PC
637
638 if (! abfd->output_has_begun
639 && ! wasm_compute_section_file_positions (abfd))
0a1b45a2 640 return false;
a6be0538
PC
641
642 if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0
643 || bfd_bwrite (location, count, abfd) != count)
0a1b45a2 644 return false;
a6be0538 645
0a1b45a2 646 return true;
a6be0538
PC
647}
648
0a1b45a2 649static bool
a6be0538
PC
650wasm_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)
0a1b45a2 656 return false;
a6be0538
PC
657
658 if (bfd_bwrite (magic, sizeof (magic), abfd) != sizeof (magic)
659 || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers))
0a1b45a2 660 return false;
a6be0538 661
0a1b45a2 662 return true;
a6be0538
PC
663}
664
0a1b45a2 665static bool
a6be0538
PC
666wasm_mkobject (bfd *abfd)
667{
668 tdata_type *tdata = (tdata_type *) bfd_alloc (abfd, sizeof (tdata_type));
669
670 if (! tdata)
0a1b45a2 671 return false;
a6be0538
PC
672
673 tdata->symbols = NULL;
674 tdata->symcount = 0;
675
676 abfd->tdata.any = tdata;
677
0a1b45a2 678 return true;
a6be0538
PC
679}
680
681static long
682wasm_get_symtab_upper_bound (bfd *abfd)
683{
684 tdata_type *tdata = abfd->tdata.any;
685
686 return (tdata->symcount + 1) * (sizeof (asymbol *));
687}
688
689static long
690wasm_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
702static asymbol *
703wasm_make_empty_symbol (bfd *abfd)
704{
986f0783 705 size_t amt = sizeof (asymbol);
a6be0538
PC
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
714static void
715wasm_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
734static void
735wasm_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
cb001c0d 744static bfd_cleanup
a6be0538
PC
745wasm_object_p (bfd *abfd)
746{
0a1b45a2 747 bool error;
0c0adcc5 748 asection *s;
a6be0538
PC
749
750 if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
751 return NULL;
752
0c0adcc5 753 if (!wasm_read_header (abfd, &error))
a6be0538
PC
754 {
755 bfd_set_error (bfd_error_wrong_format);
756 return NULL;
757 }
758
0c0adcc5 759 if (!wasm_mkobject (abfd))
a6be0538
PC
760 return NULL;
761
0c0adcc5
AM
762 if (!wasm_scan (abfd)
763 || !bfd_default_set_arch_mach (abfd, bfd_arch_wasm32, 0))
764 {
765 bfd_release (abfd, abfd->tdata.any);
766 abfd->tdata.any = NULL;
767 return NULL;
768 }
a6be0538 769
0c0adcc5
AM
770 s = bfd_get_section_by_name (abfd, WASM_NAME_SECTION);
771 if (s != NULL && wasm_scan_name_function_section (abfd, s))
a6be0538
PC
772 abfd->flags |= HAS_SYMS;
773
cb001c0d 774 return _bfd_no_cleanup;
a6be0538
PC
775}
776
777/* BFD_JUMP_TABLE_WRITE */
07d6d2b8 778#define wasm_set_arch_mach _bfd_generic_set_arch_mach
a6be0538
PC
779
780/* BFD_JUMP_TABLE_SYMBOLS */
07d6d2b8
AM
781#define wasm_get_symbol_version_string _bfd_nosymbols_get_symbol_version_string
782#define wasm_bfd_is_local_label_name bfd_generic_is_local_label_name
d00dd7dc 783#define wasm_bfd_is_target_special_symbol _bfd_bool_bfd_asymbol_false
07d6d2b8
AM
784#define wasm_get_lineno _bfd_nosymbols_get_lineno
785#define wasm_find_nearest_line _bfd_nosymbols_find_nearest_line
786#define wasm_find_line _bfd_nosymbols_find_line
787#define wasm_find_inliner_info _bfd_nosymbols_find_inliner_info
788#define wasm_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol
789#define wasm_read_minisymbols _bfd_generic_read_minisymbols
790#define wasm_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol
a6be0538
PC
791
792const bfd_target wasm_vec =
793{
07d6d2b8 794 "wasm", /* Name. */
a6be0538
PC
795 bfd_target_unknown_flavour,
796 BFD_ENDIAN_LITTLE,
797 BFD_ENDIAN_LITTLE,
798 (HAS_SYMS | WP_TEXT), /* Object flags. */
799 (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS), /* Section flags. */
07d6d2b8
AM
800 0, /* Leading underscore. */
801 ' ', /* AR_pad_char. */
802 255, /* AR_max_namelen. */
a6be0538 803 0, /* Match priority. */
d1bcae83 804 TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols. */
a6be0538
PC
805 /* Routines to byte-swap various sized integers from the data sections. */
806 bfd_getl64, bfd_getl_signed_64, bfd_putl64,
807 bfd_getl32, bfd_getl_signed_32, bfd_putl32,
808 bfd_getl16, bfd_getl_signed_16, bfd_putl16,
809
810 /* Routines to byte-swap various sized integers from the file headers. */
811 bfd_getl64, bfd_getl_signed_64, bfd_putl64,
812 bfd_getl32, bfd_getl_signed_32, bfd_putl32,
813 bfd_getl16, bfd_getl_signed_16, bfd_putl16,
814
815 {
816 _bfd_dummy_target,
817 wasm_object_p, /* bfd_check_format. */
818 _bfd_dummy_target,
819 _bfd_dummy_target,
820 },
821 {
d00dd7dc 822 _bfd_bool_bfd_false_error,
a6be0538
PC
823 wasm_mkobject,
824 _bfd_generic_mkarchive,
d00dd7dc 825 _bfd_bool_bfd_false_error,
a6be0538
PC
826 },
827 { /* bfd_write_contents. */
d00dd7dc 828 _bfd_bool_bfd_false_error,
a6be0538
PC
829 wasm_write_object_contents,
830 _bfd_write_archive_contents,
d00dd7dc 831 _bfd_bool_bfd_false_error,
a6be0538
PC
832 },
833
834 BFD_JUMP_TABLE_GENERIC (_bfd_generic),
835 BFD_JUMP_TABLE_COPY (_bfd_generic),
836 BFD_JUMP_TABLE_CORE (_bfd_nocore),
837 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
838 BFD_JUMP_TABLE_SYMBOLS (wasm),
839 BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
840 BFD_JUMP_TABLE_WRITE (wasm),
841 BFD_JUMP_TABLE_LINK (_bfd_nolink),
842 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
843
844 NULL,
845
846 NULL,
847};
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