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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 |
39 | typedef struct |
40 | { | |
41 | asymbol * symbols; | |
42 | bfd_size_type symcount; | |
43 | } tdata_type; | |
44 | ||
45 | static 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 | ||
66 | static const char * | |
67 | wasm_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 | ||
78 | static unsigned int | |
79 | wasm_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 | ||
107 | static bfd_vma | |
0a1b45a2 AM |
108 | wasm_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 | 161 | static bool |
a6be0538 PC |
162 | wasm_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 | { \ | |
185 | unsigned int length_read; \ | |
186 | (x) = _bfd_safe_read_leb128 (abfd, (p), &length_read, \ | |
0a1b45a2 | 187 | false, (end)); \ |
07d6d2b8 AM |
188 | (p) += length_read; \ |
189 | if (length_read == 0) \ | |
190 | goto error_return; \ | |
191 | } \ | |
a6be0538 PC |
192 | while (0) |
193 | ||
194 | /* Verify the magic number at the beginning of a WebAssembly module | |
195 | ABFD, setting ERRORPTR if there's a mismatch. */ | |
196 | ||
0a1b45a2 AM |
197 | static bool |
198 | wasm_read_magic (bfd *abfd, bool *errorptr) | |
a6be0538 PC |
199 | { |
200 | bfd_byte magic_const[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
201 | bfd_byte magic[SIZEOF_WASM_MAGIC]; | |
202 | ||
203 | if (bfd_bread (magic, sizeof (magic), abfd) == sizeof (magic) | |
204 | && memcmp (magic, magic_const, sizeof (magic)) == 0) | |
0a1b45a2 | 205 | return true; |
a6be0538 | 206 | |
0a1b45a2 AM |
207 | *errorptr = true; |
208 | return false; | |
a6be0538 PC |
209 | } |
210 | ||
211 | /* Read the version number from ABFD, returning TRUE if it's a supported | |
212 | version. Set ERRORPTR otherwise. */ | |
213 | ||
0a1b45a2 AM |
214 | static bool |
215 | wasm_read_version (bfd *abfd, bool *errorptr) | |
a6be0538 PC |
216 | { |
217 | bfd_byte vers_const[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
218 | bfd_byte vers[SIZEOF_WASM_VERSION]; | |
219 | ||
220 | if (bfd_bread (vers, sizeof (vers), abfd) == sizeof (vers) | |
221 | /* Don't attempt to parse newer versions, which are likely to | |
222 | require code changes. */ | |
223 | && memcmp (vers, vers_const, sizeof (vers)) == 0) | |
0a1b45a2 | 224 | return true; |
a6be0538 | 225 | |
0a1b45a2 AM |
226 | *errorptr = true; |
227 | return false; | |
a6be0538 PC |
228 | } |
229 | ||
230 | /* Read the WebAssembly header (magic number plus version number) from | |
231 | ABFD, setting ERRORPTR to TRUE if there is a mismatch. */ | |
232 | ||
0a1b45a2 AM |
233 | static bool |
234 | wasm_read_header (bfd *abfd, bool *errorptr) | |
a6be0538 PC |
235 | { |
236 | if (! wasm_read_magic (abfd, errorptr)) | |
0a1b45a2 | 237 | return false; |
a6be0538 PC |
238 | |
239 | if (! wasm_read_version (abfd, errorptr)) | |
0a1b45a2 | 240 | return false; |
a6be0538 | 241 | |
0a1b45a2 | 242 | return true; |
a6be0538 PC |
243 | } |
244 | ||
245 | /* Scan the "function" subsection of the "name" section ASECT in the | |
246 | wasm module ABFD. Create symbols. Return TRUE on success. */ | |
247 | ||
0a1b45a2 | 248 | static bool |
a6be0538 PC |
249 | wasm_scan_name_function_section (bfd *abfd, sec_ptr asect) |
250 | { | |
251 | bfd_byte *p; | |
252 | bfd_byte *end; | |
253 | bfd_vma payload_size; | |
254 | bfd_vma symcount = 0; | |
255 | tdata_type *tdata = abfd->tdata.any; | |
256 | asymbol *symbols = NULL; | |
257 | sec_ptr space_function_index; | |
1f4361a7 | 258 | size_t amt; |
a6be0538 | 259 | |
a6be0538 PC |
260 | p = asect->contents; |
261 | end = asect->contents + asect->size; | |
262 | ||
0c0adcc5 | 263 | if (!p) |
0a1b45a2 | 264 | return false; |
a6be0538 PC |
265 | |
266 | while (p < end) | |
267 | { | |
268 | bfd_byte subsection_code = *p++; | |
269 | if (subsection_code == WASM_FUNCTION_SUBSECTION) | |
07d6d2b8 | 270 | break; |
a6be0538 PC |
271 | |
272 | /* subsection_code is documented to be a varuint7, meaning that | |
07d6d2b8 AM |
273 | it has to be a single byte in the 0 - 127 range. If it isn't, |
274 | the spec must have changed underneath us, so give up. */ | |
a6be0538 | 275 | if (subsection_code & 0x80) |
0a1b45a2 | 276 | return false; |
a6be0538 PC |
277 | |
278 | READ_LEB128 (payload_size, p, end); | |
279 | ||
0c0adcc5 | 280 | if (payload_size > (size_t) (end - p)) |
0a1b45a2 | 281 | return false; |
a6be0538 PC |
282 | |
283 | p += payload_size; | |
284 | } | |
285 | ||
286 | if (p >= end) | |
0a1b45a2 | 287 | return false; |
a6be0538 PC |
288 | |
289 | READ_LEB128 (payload_size, p, end); | |
290 | ||
0c0adcc5 | 291 | if (payload_size > (size_t) (end - p)) |
0a1b45a2 | 292 | return false; |
a6be0538 PC |
293 | |
294 | end = p + payload_size; | |
295 | ||
296 | READ_LEB128 (symcount, p, end); | |
297 | ||
298 | /* Sanity check: each symbol has at least two bytes. */ | |
0c0adcc5 | 299 | if (symcount > payload_size / 2) |
0a1b45a2 | 300 | return false; |
a6be0538 PC |
301 | |
302 | tdata->symcount = symcount; | |
303 | ||
0c0adcc5 AM |
304 | space_function_index |
305 | = bfd_make_section_with_flags (abfd, WASM_SECTION_FUNCTION_INDEX, | |
306 | SEC_READONLY | SEC_CODE); | |
a6be0538 | 307 | |
0c0adcc5 AM |
308 | if (!space_function_index) |
309 | space_function_index | |
310 | = bfd_get_section_by_name (abfd, WASM_SECTION_FUNCTION_INDEX); | |
a6be0538 | 311 | |
0c0adcc5 | 312 | if (!space_function_index) |
0a1b45a2 | 313 | return false; |
a6be0538 | 314 | |
1f4361a7 AM |
315 | if (_bfd_mul_overflow (tdata->symcount, sizeof (asymbol), &amt)) |
316 | { | |
317 | bfd_set_error (bfd_error_file_too_big); | |
0a1b45a2 | 318 | return false; |
1f4361a7 AM |
319 | } |
320 | symbols = bfd_alloc (abfd, amt); | |
0c0adcc5 | 321 | if (!symbols) |
0a1b45a2 | 322 | return false; |
a6be0538 PC |
323 | |
324 | for (symcount = 0; p < end && symcount < tdata->symcount; symcount++) | |
325 | { | |
87993319 | 326 | bfd_vma idx; |
a6be0538 PC |
327 | bfd_vma len; |
328 | char *name; | |
329 | asymbol *sym; | |
330 | ||
87993319 | 331 | READ_LEB128 (idx, p, end); |
a6be0538 PC |
332 | READ_LEB128 (len, p, end); |
333 | ||
0c0adcc5 | 334 | if (len > (size_t) (end - p)) |
07d6d2b8 | 335 | goto error_return; |
a6be0538 | 336 | |
0c0adcc5 AM |
337 | name = bfd_alloc (abfd, len + 1); |
338 | if (!name) | |
07d6d2b8 | 339 | goto error_return; |
a6be0538 PC |
340 | |
341 | memcpy (name, p, len); | |
0c0adcc5 | 342 | name[len] = 0; |
a6be0538 PC |
343 | p += len; |
344 | ||
345 | sym = &symbols[symcount]; | |
346 | sym->the_bfd = abfd; | |
347 | sym->name = name; | |
87993319 | 348 | sym->value = idx; |
a6be0538 PC |
349 | sym->flags = BSF_GLOBAL | BSF_FUNCTION; |
350 | sym->section = space_function_index; | |
351 | sym->udata.p = NULL; | |
352 | } | |
353 | ||
354 | if (symcount < tdata->symcount) | |
355 | goto error_return; | |
356 | ||
357 | tdata->symbols = symbols; | |
358 | abfd->symcount = symcount; | |
359 | ||
0a1b45a2 | 360 | return true; |
a6be0538 PC |
361 | |
362 | error_return: | |
a6be0538 | 363 | bfd_release (abfd, symbols); |
0a1b45a2 | 364 | return false; |
a6be0538 PC |
365 | } |
366 | ||
367 | /* Read a byte from ABFD and return it, or EOF for EOF or error. | |
368 | Set ERRORPTR on non-EOF error. */ | |
369 | ||
370 | static int | |
0a1b45a2 | 371 | wasm_read_byte (bfd *abfd, bool *errorptr) |
a6be0538 PC |
372 | { |
373 | bfd_byte byte; | |
374 | ||
375 | if (bfd_bread (&byte, (bfd_size_type) 1, abfd) != 1) | |
376 | { | |
377 | if (bfd_get_error () != bfd_error_file_truncated) | |
0a1b45a2 | 378 | *errorptr = true; |
a6be0538 PC |
379 | return EOF; |
380 | } | |
381 | ||
382 | return byte; | |
383 | } | |
384 | ||
385 | /* Scan the wasm module ABFD, creating sections and symbols. | |
386 | Return TRUE on success. */ | |
387 | ||
0a1b45a2 | 388 | static bool |
a6be0538 PC |
389 | wasm_scan (bfd *abfd) |
390 | { | |
0a1b45a2 | 391 | bool error = false; |
a6be0538 PC |
392 | /* Fake VMAs for now. Choose 0x80000000 as base to avoid clashes |
393 | with actual data addresses. */ | |
394 | bfd_vma vma = 0x80000000; | |
395 | int section_code; | |
396 | unsigned int bytes_read; | |
a6be0538 PC |
397 | asection *bfdsec; |
398 | ||
399 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
400 | goto error_return; | |
401 | ||
0c0adcc5 | 402 | if (!wasm_read_header (abfd, &error)) |
a6be0538 PC |
403 | goto error_return; |
404 | ||
405 | while ((section_code = wasm_read_byte (abfd, &error)) != EOF) | |
406 | { | |
407 | if (section_code != 0) | |
07d6d2b8 AM |
408 | { |
409 | const char *sname = wasm_section_code_to_name (section_code); | |
410 | ||
0c0adcc5 | 411 | if (!sname) |
07d6d2b8 AM |
412 | goto error_return; |
413 | ||
0c0adcc5 AM |
414 | bfdsec = bfd_make_section_anyway_with_flags (abfd, sname, |
415 | SEC_HAS_CONTENTS); | |
07d6d2b8 AM |
416 | if (bfdsec == NULL) |
417 | goto error_return; | |
07d6d2b8 | 418 | |
0a1b45a2 | 419 | bfdsec->size = wasm_read_leb128 (abfd, &error, &bytes_read, false); |
07d6d2b8 AM |
420 | if (error) |
421 | goto error_return; | |
07d6d2b8 | 422 | } |
a6be0538 | 423 | else |
07d6d2b8 AM |
424 | { |
425 | bfd_vma payload_len; | |
07d6d2b8 | 426 | bfd_vma namelen; |
0c0adcc5 | 427 | char *name; |
07d6d2b8 | 428 | char *prefix = WASM_SECTION_PREFIX; |
0c0adcc5 | 429 | size_t prefixlen = strlen (prefix); |
2f57795b | 430 | ufile_ptr filesize; |
07d6d2b8 | 431 | |
0a1b45a2 | 432 | payload_len = wasm_read_leb128 (abfd, &error, &bytes_read, false); |
07d6d2b8 AM |
433 | if (error) |
434 | goto error_return; | |
0a1b45a2 | 435 | namelen = wasm_read_leb128 (abfd, &error, &bytes_read, false); |
2f57795b AM |
436 | if (error || bytes_read > payload_len |
437 | || namelen > payload_len - bytes_read) | |
07d6d2b8 | 438 | goto error_return; |
2f57795b AM |
439 | payload_len -= namelen + bytes_read; |
440 | filesize = bfd_get_file_size (abfd); | |
441 | if (filesize != 0 && namelen > filesize) | |
442 | { | |
443 | bfd_set_error (bfd_error_file_truncated); | |
0a1b45a2 | 444 | return false; |
2f57795b | 445 | } |
0c0adcc5 AM |
446 | name = bfd_alloc (abfd, namelen + prefixlen + 1); |
447 | if (!name) | |
07d6d2b8 | 448 | goto error_return; |
0c0adcc5 AM |
449 | memcpy (name, prefix, prefixlen); |
450 | if (bfd_bread (name + prefixlen, namelen, abfd) != namelen) | |
a6be0538 | 451 | goto error_return; |
0c0adcc5 | 452 | name[prefixlen + namelen] = 0; |
a6be0538 | 453 | |
0c0adcc5 AM |
454 | bfdsec = bfd_make_section_anyway_with_flags (abfd, name, |
455 | SEC_HAS_CONTENTS); | |
07d6d2b8 AM |
456 | if (bfdsec == NULL) |
457 | goto error_return; | |
a6be0538 | 458 | |
2f57795b | 459 | bfdsec->size = payload_len; |
07d6d2b8 | 460 | } |
a6be0538 | 461 | |
2f57795b AM |
462 | bfdsec->vma = vma; |
463 | bfdsec->lma = vma; | |
464 | bfdsec->alignment_power = 0; | |
465 | bfdsec->filepos = bfd_tell (abfd); | |
a6be0538 | 466 | if (bfdsec->size != 0) |
07d6d2b8 | 467 | { |
2bb3687b AM |
468 | bfdsec->contents = _bfd_alloc_and_read (abfd, bfdsec->size, |
469 | bfdsec->size); | |
0c0adcc5 | 470 | if (!bfdsec->contents) |
07d6d2b8 | 471 | goto error_return; |
07d6d2b8 | 472 | } |
a6be0538 PC |
473 | |
474 | vma += bfdsec->size; | |
475 | } | |
476 | ||
477 | /* Make sure we're at actual EOF. There's no indication in the | |
478 | WebAssembly format of how long the file is supposed to be. */ | |
479 | if (error) | |
480 | goto error_return; | |
481 | ||
0a1b45a2 | 482 | return true; |
a6be0538 PC |
483 | |
484 | error_return: | |
0a1b45a2 | 485 | return false; |
a6be0538 PC |
486 | } |
487 | ||
488 | /* Put a numbered section ASECT of ABFD into the table of numbered | |
489 | sections pointed to by FSARG. */ | |
490 | ||
491 | static void | |
492 | wasm_register_section (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 | 493 | asection *asect, |
a6be0538 PC |
494 | void *fsarg) |
495 | { | |
496 | sec_ptr *numbered_sections = fsarg; | |
87993319 | 497 | int idx = wasm_section_name_to_code (asect->name); |
a6be0538 | 498 | |
87993319 | 499 | if (idx == 0) |
a6be0538 PC |
500 | return; |
501 | ||
87993319 | 502 | numbered_sections[idx] = asect; |
a6be0538 PC |
503 | } |
504 | ||
505 | struct compute_section_arg | |
506 | { | |
507 | bfd_vma pos; | |
0a1b45a2 | 508 | bool failed; |
a6be0538 PC |
509 | }; |
510 | ||
511 | /* Compute the file position of ABFD's section ASECT. FSARG is a | |
512 | pointer to the current file position. | |
513 | ||
514 | We allow section names of the form .wasm.id to encode the numbered | |
515 | section with ID id, if it exists; otherwise, a custom section with | |
516 | ID "id" is produced. Arbitrary section names are for sections that | |
517 | are assumed already to contain a section header; those are appended | |
518 | to the WebAssembly module verbatim. */ | |
519 | ||
520 | static void | |
521 | wasm_compute_custom_section_file_position (bfd *abfd, | |
522 | sec_ptr asect, | |
07d6d2b8 | 523 | void *fsarg) |
a6be0538 PC |
524 | { |
525 | struct compute_section_arg *fs = fsarg; | |
87993319 | 526 | int idx; |
a6be0538 PC |
527 | |
528 | if (fs->failed) | |
529 | return; | |
530 | ||
87993319 | 531 | idx = wasm_section_name_to_code (asect->name); |
a6be0538 | 532 | |
87993319 | 533 | if (idx != 0) |
a6be0538 PC |
534 | return; |
535 | ||
08dedd66 | 536 | if (startswith (asect->name, WASM_SECTION_PREFIX)) |
a6be0538 PC |
537 | { |
538 | const char *name = asect->name + strlen (WASM_SECTION_PREFIX); | |
539 | bfd_size_type payload_len = asect->size; | |
540 | bfd_size_type name_len = strlen (name); | |
541 | bfd_size_type nl = name_len; | |
542 | ||
543 | payload_len += name_len; | |
544 | ||
545 | do | |
07d6d2b8 AM |
546 | { |
547 | payload_len++; | |
548 | nl >>= 7; | |
549 | } | |
a6be0538 PC |
550 | while (nl); |
551 | ||
552 | bfd_seek (abfd, fs->pos, SEEK_SET); | |
553 | if (! wasm_write_uleb128 (abfd, 0) | |
07d6d2b8 AM |
554 | || ! wasm_write_uleb128 (abfd, payload_len) |
555 | || ! wasm_write_uleb128 (abfd, name_len) | |
556 | || bfd_bwrite (name, name_len, abfd) != name_len) | |
557 | goto error_return; | |
a6be0538 PC |
558 | fs->pos = asect->filepos = bfd_tell (abfd); |
559 | } | |
560 | else | |
561 | { | |
562 | asect->filepos = fs->pos; | |
563 | } | |
564 | ||
565 | ||
566 | fs->pos += asect->size; | |
567 | return; | |
568 | ||
569 | error_return: | |
0a1b45a2 | 570 | fs->failed = true; |
a6be0538 PC |
571 | } |
572 | ||
573 | /* Compute the file positions for the sections of ABFD. Currently, | |
574 | this writes all numbered sections first, in order, then all custom | |
575 | sections, in section order. | |
576 | ||
577 | The spec says that the numbered sections must appear in order of | |
578 | their ids, but custom sections can appear in any position and any | |
579 | order, and more than once. FIXME: support that. */ | |
580 | ||
0a1b45a2 | 581 | static bool |
a6be0538 PC |
582 | wasm_compute_section_file_positions (bfd *abfd) |
583 | { | |
584 | bfd_byte magic[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
585 | bfd_byte vers[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
586 | sec_ptr numbered_sections[WASM_NUMBERED_SECTIONS]; | |
587 | struct compute_section_arg fs; | |
588 | unsigned int i; | |
589 | ||
590 | bfd_seek (abfd, (bfd_vma) 0, SEEK_SET); | |
591 | ||
592 | if (bfd_bwrite (magic, sizeof (magic), abfd) != (sizeof magic) | |
593 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
0a1b45a2 | 594 | return false; |
a6be0538 PC |
595 | |
596 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
597 | numbered_sections[i] = NULL; | |
598 | ||
599 | bfd_map_over_sections (abfd, wasm_register_section, numbered_sections); | |
600 | ||
601 | fs.pos = bfd_tell (abfd); | |
602 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
603 | { | |
604 | sec_ptr sec = numbered_sections[i]; | |
605 | bfd_size_type size; | |
606 | ||
607 | if (! sec) | |
07d6d2b8 | 608 | continue; |
a6be0538 PC |
609 | size = sec->size; |
610 | if (bfd_seek (abfd, fs.pos, SEEK_SET) != 0) | |
0a1b45a2 | 611 | return false; |
a6be0538 | 612 | if (! wasm_write_uleb128 (abfd, i) |
07d6d2b8 | 613 | || ! wasm_write_uleb128 (abfd, size)) |
0a1b45a2 | 614 | return false; |
a6be0538 PC |
615 | fs.pos = sec->filepos = bfd_tell (abfd); |
616 | fs.pos += size; | |
617 | } | |
618 | ||
0a1b45a2 | 619 | fs.failed = false; |
a6be0538 PC |
620 | |
621 | bfd_map_over_sections (abfd, wasm_compute_custom_section_file_position, &fs); | |
622 | ||
623 | if (fs.failed) | |
0a1b45a2 | 624 | return false; |
a6be0538 | 625 | |
0a1b45a2 | 626 | abfd->output_has_begun = true; |
a6be0538 | 627 | |
0a1b45a2 | 628 | return true; |
a6be0538 PC |
629 | } |
630 | ||
0a1b45a2 | 631 | static bool |
a6be0538 | 632 | wasm_set_section_contents (bfd *abfd, |
07d6d2b8 AM |
633 | sec_ptr section, |
634 | const void *location, | |
635 | file_ptr offset, | |
636 | bfd_size_type count) | |
a6be0538 PC |
637 | { |
638 | if (count == 0) | |
0a1b45a2 | 639 | return true; |
a6be0538 PC |
640 | |
641 | if (! abfd->output_has_begun | |
642 | && ! wasm_compute_section_file_positions (abfd)) | |
0a1b45a2 | 643 | return false; |
a6be0538 PC |
644 | |
645 | if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 | |
646 | || bfd_bwrite (location, count, abfd) != count) | |
0a1b45a2 | 647 | return false; |
a6be0538 | 648 | |
0a1b45a2 | 649 | return true; |
a6be0538 PC |
650 | } |
651 | ||
0a1b45a2 | 652 | static bool |
a6be0538 PC |
653 | wasm_write_object_contents (bfd* abfd) |
654 | { | |
655 | bfd_byte magic[] = WASM_MAGIC; | |
656 | bfd_byte vers[] = WASM_VERSION; | |
657 | ||
658 | if (bfd_seek (abfd, 0, SEEK_SET) != 0) | |
0a1b45a2 | 659 | return false; |
a6be0538 PC |
660 | |
661 | if (bfd_bwrite (magic, sizeof (magic), abfd) != sizeof (magic) | |
662 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
0a1b45a2 | 663 | return false; |
a6be0538 | 664 | |
0a1b45a2 | 665 | return true; |
a6be0538 PC |
666 | } |
667 | ||
0a1b45a2 | 668 | static bool |
a6be0538 PC |
669 | wasm_mkobject (bfd *abfd) |
670 | { | |
671 | tdata_type *tdata = (tdata_type *) bfd_alloc (abfd, sizeof (tdata_type)); | |
672 | ||
673 | if (! tdata) | |
0a1b45a2 | 674 | return false; |
a6be0538 PC |
675 | |
676 | tdata->symbols = NULL; | |
677 | tdata->symcount = 0; | |
678 | ||
679 | abfd->tdata.any = tdata; | |
680 | ||
0a1b45a2 | 681 | return true; |
a6be0538 PC |
682 | } |
683 | ||
684 | static long | |
685 | wasm_get_symtab_upper_bound (bfd *abfd) | |
686 | { | |
687 | tdata_type *tdata = abfd->tdata.any; | |
688 | ||
689 | return (tdata->symcount + 1) * (sizeof (asymbol *)); | |
690 | } | |
691 | ||
692 | static long | |
693 | wasm_canonicalize_symtab (bfd *abfd, asymbol **alocation) | |
694 | { | |
695 | tdata_type *tdata = abfd->tdata.any; | |
696 | size_t i; | |
697 | ||
698 | for (i = 0; i < tdata->symcount; i++) | |
699 | alocation[i] = &tdata->symbols[i]; | |
700 | alocation[i] = NULL; | |
701 | ||
702 | return tdata->symcount; | |
703 | } | |
704 | ||
705 | static asymbol * | |
706 | wasm_make_empty_symbol (bfd *abfd) | |
707 | { | |
986f0783 | 708 | size_t amt = sizeof (asymbol); |
a6be0538 PC |
709 | asymbol *new_symbol = (asymbol *) bfd_zalloc (abfd, amt); |
710 | ||
711 | if (! new_symbol) | |
712 | return NULL; | |
713 | new_symbol->the_bfd = abfd; | |
714 | return new_symbol; | |
715 | } | |
716 | ||
717 | static void | |
718 | wasm_print_symbol (bfd *abfd, | |
07d6d2b8 AM |
719 | void * filep, |
720 | asymbol *symbol, | |
721 | bfd_print_symbol_type how) | |
a6be0538 PC |
722 | { |
723 | FILE *file = (FILE *) filep; | |
724 | ||
725 | switch (how) | |
726 | { | |
727 | case bfd_print_symbol_name: | |
728 | fprintf (file, "%s", symbol->name); | |
729 | break; | |
730 | ||
731 | default: | |
732 | bfd_print_symbol_vandf (abfd, filep, symbol); | |
733 | fprintf (file, " %-5s %s", symbol->section->name, symbol->name); | |
734 | } | |
735 | } | |
736 | ||
737 | static void | |
738 | wasm_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 AM |
739 | asymbol *symbol, |
740 | symbol_info *ret) | |
a6be0538 PC |
741 | { |
742 | bfd_symbol_info (symbol, ret); | |
743 | } | |
744 | ||
745 | /* Check whether ABFD is a WebAssembly module; if so, scan it. */ | |
746 | ||
cb001c0d | 747 | static bfd_cleanup |
a6be0538 PC |
748 | wasm_object_p (bfd *abfd) |
749 | { | |
0a1b45a2 | 750 | bool error; |
0c0adcc5 | 751 | asection *s; |
a6be0538 PC |
752 | |
753 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
754 | return NULL; | |
755 | ||
0c0adcc5 | 756 | if (!wasm_read_header (abfd, &error)) |
a6be0538 PC |
757 | { |
758 | bfd_set_error (bfd_error_wrong_format); | |
759 | return NULL; | |
760 | } | |
761 | ||
0c0adcc5 | 762 | if (!wasm_mkobject (abfd)) |
a6be0538 PC |
763 | return NULL; |
764 | ||
0c0adcc5 AM |
765 | if (!wasm_scan (abfd) |
766 | || !bfd_default_set_arch_mach (abfd, bfd_arch_wasm32, 0)) | |
767 | { | |
768 | bfd_release (abfd, abfd->tdata.any); | |
769 | abfd->tdata.any = NULL; | |
770 | return NULL; | |
771 | } | |
a6be0538 | 772 | |
0c0adcc5 AM |
773 | s = bfd_get_section_by_name (abfd, WASM_NAME_SECTION); |
774 | if (s != NULL && wasm_scan_name_function_section (abfd, s)) | |
a6be0538 PC |
775 | abfd->flags |= HAS_SYMS; |
776 | ||
cb001c0d | 777 | return _bfd_no_cleanup; |
a6be0538 PC |
778 | } |
779 | ||
780 | /* BFD_JUMP_TABLE_WRITE */ | |
07d6d2b8 | 781 | #define wasm_set_arch_mach _bfd_generic_set_arch_mach |
a6be0538 PC |
782 | |
783 | /* BFD_JUMP_TABLE_SYMBOLS */ | |
07d6d2b8 AM |
784 | #define wasm_get_symbol_version_string _bfd_nosymbols_get_symbol_version_string |
785 | #define wasm_bfd_is_local_label_name bfd_generic_is_local_label_name | |
d00dd7dc | 786 | #define wasm_bfd_is_target_special_symbol _bfd_bool_bfd_asymbol_false |
07d6d2b8 AM |
787 | #define wasm_get_lineno _bfd_nosymbols_get_lineno |
788 | #define wasm_find_nearest_line _bfd_nosymbols_find_nearest_line | |
789 | #define wasm_find_line _bfd_nosymbols_find_line | |
790 | #define wasm_find_inliner_info _bfd_nosymbols_find_inliner_info | |
791 | #define wasm_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol | |
792 | #define wasm_read_minisymbols _bfd_generic_read_minisymbols | |
793 | #define wasm_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol | |
a6be0538 PC |
794 | |
795 | const bfd_target wasm_vec = | |
796 | { | |
07d6d2b8 | 797 | "wasm", /* Name. */ |
a6be0538 PC |
798 | bfd_target_unknown_flavour, |
799 | BFD_ENDIAN_LITTLE, | |
800 | BFD_ENDIAN_LITTLE, | |
801 | (HAS_SYMS | WP_TEXT), /* Object flags. */ | |
802 | (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS), /* Section flags. */ | |
07d6d2b8 AM |
803 | 0, /* Leading underscore. */ |
804 | ' ', /* AR_pad_char. */ | |
805 | 255, /* AR_max_namelen. */ | |
a6be0538 | 806 | 0, /* Match priority. */ |
d1bcae83 | 807 | TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols. */ |
a6be0538 PC |
808 | /* Routines to byte-swap various sized integers from the data sections. */ |
809 | bfd_getl64, bfd_getl_signed_64, bfd_putl64, | |
810 | bfd_getl32, bfd_getl_signed_32, bfd_putl32, | |
811 | bfd_getl16, bfd_getl_signed_16, bfd_putl16, | |
812 | ||
813 | /* Routines to byte-swap various sized integers from the file headers. */ | |
814 | bfd_getl64, bfd_getl_signed_64, bfd_putl64, | |
815 | bfd_getl32, bfd_getl_signed_32, bfd_putl32, | |
816 | bfd_getl16, bfd_getl_signed_16, bfd_putl16, | |
817 | ||
818 | { | |
819 | _bfd_dummy_target, | |
820 | wasm_object_p, /* bfd_check_format. */ | |
821 | _bfd_dummy_target, | |
822 | _bfd_dummy_target, | |
823 | }, | |
824 | { | |
d00dd7dc | 825 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
826 | wasm_mkobject, |
827 | _bfd_generic_mkarchive, | |
d00dd7dc | 828 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
829 | }, |
830 | { /* bfd_write_contents. */ | |
d00dd7dc | 831 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
832 | wasm_write_object_contents, |
833 | _bfd_write_archive_contents, | |
d00dd7dc | 834 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
835 | }, |
836 | ||
837 | BFD_JUMP_TABLE_GENERIC (_bfd_generic), | |
838 | BFD_JUMP_TABLE_COPY (_bfd_generic), | |
839 | BFD_JUMP_TABLE_CORE (_bfd_nocore), | |
840 | BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), | |
841 | BFD_JUMP_TABLE_SYMBOLS (wasm), | |
842 | BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), | |
843 | BFD_JUMP_TABLE_WRITE (wasm), | |
844 | BFD_JUMP_TABLE_LINK (_bfd_nolink), | |
845 | BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), | |
846 | ||
847 | NULL, | |
848 | ||
849 | NULL, | |
850 | }; |