Commit | Line | Data |
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62ecb94c | 1 | /* Opcode printing code for the WebAssembly target |
250d07de | 2 | Copyright (C) 2017-2021 Free Software Foundation, Inc. |
62ecb94c PC |
3 | |
4 | This file is part of libopcodes. | |
5 | ||
6 | This library is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 3 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | It is distributed in the hope that it will be useful, but WITHOUT | |
12 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
13 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
14 | License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; if not, write to the Free Software | |
18 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
19 | MA 02110-1301, USA. */ | |
20 | ||
21 | #include "sysdep.h" | |
88c1242d | 22 | #include "disassemble.h" |
62ecb94c PC |
23 | #include "opintl.h" |
24 | #include "safe-ctype.h" | |
25 | #include "floatformat.h" | |
62ecb94c PC |
26 | #include "libiberty.h" |
27 | #include "elf-bfd.h" | |
28 | #include "elf/internal.h" | |
29 | #include "elf/wasm32.h" | |
3dfb1b6d | 30 | #include <stdint.h> |
62ecb94c | 31 | |
b9b204b3 AM |
32 | #ifdef HAVE_LIMITS_H |
33 | #include <limits.h> | |
34 | #endif | |
35 | #ifndef CHAR_BIT | |
36 | #define CHAR_BIT 8 | |
37 | #endif | |
38 | ||
62ecb94c PC |
39 | /* Type names for blocks and signatures. */ |
40 | #define BLOCK_TYPE_NONE 0x40 | |
41 | #define BLOCK_TYPE_I32 0x7f | |
42 | #define BLOCK_TYPE_I64 0x7e | |
43 | #define BLOCK_TYPE_F32 0x7d | |
44 | #define BLOCK_TYPE_F64 0x7c | |
45 | ||
46 | enum wasm_class | |
47 | { | |
48 | wasm_typed, | |
49 | wasm_special, | |
50 | wasm_break, | |
51 | wasm_break_if, | |
52 | wasm_break_table, | |
53 | wasm_return, | |
54 | wasm_call, | |
55 | wasm_call_import, | |
56 | wasm_call_indirect, | |
57 | wasm_get_local, | |
58 | wasm_set_local, | |
59 | wasm_tee_local, | |
60 | wasm_drop, | |
61 | wasm_constant_i32, | |
62 | wasm_constant_i64, | |
63 | wasm_constant_f32, | |
64 | wasm_constant_f64, | |
65 | wasm_unary, | |
66 | wasm_binary, | |
67 | wasm_conv, | |
68 | wasm_load, | |
69 | wasm_store, | |
70 | wasm_select, | |
71 | wasm_relational, | |
72 | wasm_eqz, | |
73 | wasm_current_memory, | |
74 | wasm_grow_memory, | |
75 | wasm_signature | |
76 | }; | |
77 | ||
78 | struct wasm32_private_data | |
79 | { | |
78933a4a AM |
80 | bool print_registers; |
81 | bool print_well_known_globals; | |
62ecb94c PC |
82 | |
83 | /* Limit valid symbols to those with a given prefix. */ | |
84 | const char *section_prefix; | |
85 | }; | |
86 | ||
87 | typedef struct | |
88 | { | |
89 | const char *name; | |
90 | const char *description; | |
91 | } wasm32_options_t; | |
92 | ||
93 | static const wasm32_options_t options[] = | |
94 | { | |
95 | { "registers", N_("Disassemble \"register\" names") }, | |
96 | { "globals", N_("Name well-known globals") }, | |
97 | }; | |
98 | ||
99 | #define WASM_OPCODE(opcode, name, intype, outtype, clas, signedness) \ | |
100 | { name, wasm_ ## clas, opcode }, | |
101 | ||
102 | struct wasm32_opcode_s | |
103 | { | |
104 | const char *name; | |
105 | enum wasm_class clas; | |
106 | unsigned char opcode; | |
107 | } wasm32_opcodes[] = | |
108 | { | |
109 | #include "opcode/wasm.h" | |
110 | { NULL, 0, 0 } | |
111 | }; | |
112 | ||
113 | /* Parse the disassembler options in OPTS and initialize INFO. */ | |
114 | ||
115 | static void | |
116 | parse_wasm32_disassembler_options (struct disassemble_info *info, | |
117 | const char *opts) | |
118 | { | |
119 | struct wasm32_private_data *private = info->private_data; | |
120 | ||
121 | while (opts != NULL) | |
122 | { | |
08dedd66 | 123 | if (startswith (opts, "registers")) |
78933a4a | 124 | private->print_registers = true; |
08dedd66 | 125 | else if (startswith (opts, "globals")) |
78933a4a | 126 | private->print_well_known_globals = true; |
62ecb94c PC |
127 | |
128 | opts = strchr (opts, ','); | |
129 | if (opts) | |
130 | opts++; | |
131 | } | |
132 | } | |
133 | ||
134 | /* Check whether SYM is valid. Special-case absolute symbols, which | |
135 | are unhelpful to print, and arguments to a "call" insn, which we | |
136 | want to be in a section matching a given prefix. */ | |
137 | ||
78933a4a | 138 | static bool |
62ecb94c PC |
139 | wasm32_symbol_is_valid (asymbol *sym, |
140 | struct disassemble_info *info) | |
141 | { | |
142 | struct wasm32_private_data *private_data = info->private_data; | |
143 | ||
144 | if (sym == NULL) | |
78933a4a | 145 | return false; |
62ecb94c PC |
146 | |
147 | if (strcmp(sym->section->name, "*ABS*") == 0) | |
78933a4a | 148 | return false; |
62ecb94c PC |
149 | |
150 | if (private_data && private_data->section_prefix != NULL | |
151 | && strncmp (sym->section->name, private_data->section_prefix, | |
152 | strlen (private_data->section_prefix))) | |
78933a4a | 153 | return false; |
62ecb94c | 154 | |
78933a4a | 155 | return true; |
62ecb94c PC |
156 | } |
157 | ||
158 | /* Initialize the disassembler structures for INFO. */ | |
159 | ||
160 | void | |
161 | disassemble_init_wasm32 (struct disassemble_info *info) | |
162 | { | |
163 | if (info->private_data == NULL) | |
164 | { | |
165 | static struct wasm32_private_data private; | |
166 | ||
78933a4a AM |
167 | private.print_registers = false; |
168 | private.print_well_known_globals = false; | |
62ecb94c PC |
169 | private.section_prefix = NULL; |
170 | ||
171 | info->private_data = &private; | |
172 | } | |
173 | ||
174 | if (info->disassembler_options) | |
175 | { | |
176 | parse_wasm32_disassembler_options (info, info->disassembler_options); | |
177 | ||
178 | info->disassembler_options = NULL; | |
179 | } | |
180 | ||
181 | info->symbol_is_valid = wasm32_symbol_is_valid; | |
182 | } | |
183 | ||
184 | /* Read an LEB128-encoded integer from INFO at address PC, reading one | |
185 | byte at a time. Set ERROR_RETURN if no complete integer could be | |
186 | read, LENGTH_RETURN to the number oof bytes read (including bytes | |
187 | in incomplete numbers). SIGN means interpret the number as | |
188 | SLEB128. Unfortunately, this is a duplicate of wasm-module.c's | |
189 | wasm_read_leb128 (). */ | |
190 | ||
191 | static uint64_t | |
78933a4a AM |
192 | wasm_read_leb128 (bfd_vma pc, |
193 | struct disassemble_info *info, | |
194 | bool *error_return, | |
195 | unsigned int *length_return, | |
196 | bool sign) | |
62ecb94c PC |
197 | { |
198 | uint64_t result = 0; | |
199 | unsigned int num_read = 0; | |
200 | unsigned int shift = 0; | |
201 | unsigned char byte = 0; | |
b9b204b3 | 202 | unsigned char lost, mask; |
27c1c427 | 203 | int status = 1; |
62ecb94c PC |
204 | |
205 | while (info->read_memory_func (pc + num_read, &byte, 1, info) == 0) | |
206 | { | |
207 | num_read++; | |
208 | ||
b9b204b3 | 209 | if (shift < CHAR_BIT * sizeof (result)) |
27c1c427 AM |
210 | { |
211 | result |= ((uint64_t) (byte & 0x7f)) << shift; | |
b9b204b3 AM |
212 | /* These bits overflowed. */ |
213 | lost = byte ^ (result >> shift); | |
214 | /* And this is the mask of possible overflow bits. */ | |
215 | mask = 0x7f ^ ((uint64_t) 0x7f << shift >> shift); | |
27c1c427 AM |
216 | shift += 7; |
217 | } | |
b9b204b3 AM |
218 | else |
219 | { | |
220 | lost = byte; | |
221 | mask = 0x7f; | |
222 | } | |
223 | if ((lost & mask) != (sign && (int64_t) result < 0 ? mask : 0)) | |
27c1c427 | 224 | status |= 2; |
62ecb94c | 225 | |
62ecb94c | 226 | if ((byte & 0x80) == 0) |
27c1c427 AM |
227 | { |
228 | status &= ~1; | |
b9b204b3 | 229 | if (sign && shift < CHAR_BIT * sizeof (result) && (byte & 0x40)) |
27c1c427 AM |
230 | result |= -((uint64_t) 1 << shift); |
231 | break; | |
232 | } | |
62ecb94c PC |
233 | } |
234 | ||
235 | if (length_return != NULL) | |
236 | *length_return = num_read; | |
237 | if (error_return != NULL) | |
27c1c427 | 238 | *error_return = status != 0; |
62ecb94c PC |
239 | |
240 | return result; | |
241 | } | |
242 | ||
243 | /* Read a 32-bit IEEE float from PC using INFO, convert it to a host | |
244 | double, and store it at VALUE. */ | |
245 | ||
246 | static int | |
247 | read_f32 (double *value, bfd_vma pc, struct disassemble_info *info) | |
248 | { | |
249 | bfd_byte buf[4]; | |
250 | ||
251 | if (info->read_memory_func (pc, buf, sizeof (buf), info)) | |
252 | return -1; | |
253 | ||
254 | floatformat_to_double (&floatformat_ieee_single_little, buf, | |
255 | value); | |
256 | ||
257 | return sizeof (buf); | |
258 | } | |
259 | ||
260 | /* Read a 64-bit IEEE float from PC using INFO, convert it to a host | |
261 | double, and store it at VALUE. */ | |
262 | ||
263 | static int | |
264 | read_f64 (double *value, bfd_vma pc, struct disassemble_info *info) | |
265 | { | |
266 | bfd_byte buf[8]; | |
267 | ||
268 | if (info->read_memory_func (pc, buf, sizeof (buf), info)) | |
269 | return -1; | |
270 | ||
271 | floatformat_to_double (&floatformat_ieee_double_little, buf, | |
272 | value); | |
273 | ||
274 | return sizeof (buf); | |
275 | } | |
276 | ||
277 | /* Main disassembly routine. Disassemble insn at PC using INFO. */ | |
278 | ||
279 | int | |
280 | print_insn_wasm32 (bfd_vma pc, struct disassemble_info *info) | |
281 | { | |
282 | unsigned char opcode; | |
283 | struct wasm32_opcode_s *op; | |
284 | bfd_byte buffer[16]; | |
285 | void *stream = info->stream; | |
286 | fprintf_ftype prin = info->fprintf_func; | |
287 | struct wasm32_private_data *private_data = info->private_data; | |
febda64f AM |
288 | uint64_t val; |
289 | int len; | |
290 | unsigned int bytes_read; | |
78933a4a | 291 | bool error; |
62ecb94c PC |
292 | |
293 | if (info->read_memory_func (pc, buffer, 1, info)) | |
294 | return -1; | |
295 | ||
296 | opcode = buffer[0]; | |
297 | ||
298 | for (op = wasm32_opcodes; op->name; op++) | |
299 | if (op->opcode == opcode) | |
300 | break; | |
301 | ||
302 | if (!op->name) | |
303 | { | |
304 | prin (stream, "\t.byte 0x%02x\n", buffer[0]); | |
305 | return 1; | |
306 | } | |
febda64f AM |
307 | |
308 | len = 1; | |
309 | ||
310 | prin (stream, "\t"); | |
311 | prin (stream, "%s", op->name); | |
312 | ||
313 | if (op->clas == wasm_typed) | |
62ecb94c | 314 | { |
78933a4a | 315 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, false); |
febda64f AM |
316 | if (error) |
317 | return -1; | |
318 | len += bytes_read; | |
319 | switch (val) | |
320 | { | |
321 | case BLOCK_TYPE_NONE: | |
322 | prin (stream, "[]"); | |
323 | break; | |
324 | case BLOCK_TYPE_I32: | |
325 | prin (stream, "[i]"); | |
326 | break; | |
327 | case BLOCK_TYPE_I64: | |
328 | prin (stream, "[l]"); | |
329 | break; | |
330 | case BLOCK_TYPE_F32: | |
331 | prin (stream, "[f]"); | |
332 | break; | |
333 | case BLOCK_TYPE_F64: | |
334 | prin (stream, "[d]"); | |
335 | break; | |
336 | default: | |
337 | return -1; | |
338 | } | |
339 | } | |
340 | ||
341 | switch (op->clas) | |
342 | { | |
343 | case wasm_special: | |
344 | case wasm_eqz: | |
345 | case wasm_binary: | |
346 | case wasm_unary: | |
347 | case wasm_conv: | |
348 | case wasm_relational: | |
349 | case wasm_drop: | |
350 | case wasm_signature: | |
351 | case wasm_call_import: | |
352 | case wasm_typed: | |
353 | case wasm_select: | |
354 | break; | |
355 | ||
356 | case wasm_break_table: | |
357 | { | |
358 | uint32_t target_count, i; | |
359 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, | |
78933a4a | 360 | false); |
febda64f AM |
361 | target_count = val; |
362 | if (error || target_count != val || target_count == (uint32_t) -1) | |
363 | return -1; | |
364 | len += bytes_read; | |
365 | prin (stream, " %u", target_count); | |
366 | for (i = 0; i < target_count + 1; i++) | |
367 | { | |
368 | uint32_t target; | |
369 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, | |
78933a4a | 370 | false); |
febda64f AM |
371 | target = val; |
372 | if (error || target != val) | |
373 | return -1; | |
374 | len += bytes_read; | |
375 | prin (stream, " %u", target); | |
376 | } | |
377 | } | |
378 | break; | |
379 | ||
380 | case wasm_break: | |
381 | case wasm_break_if: | |
382 | { | |
383 | uint32_t depth; | |
384 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, | |
78933a4a | 385 | false); |
febda64f AM |
386 | depth = val; |
387 | if (error || depth != val) | |
388 | return -1; | |
389 | len += bytes_read; | |
390 | prin (stream, " %u", depth); | |
391 | } | |
392 | break; | |
393 | ||
394 | case wasm_return: | |
395 | break; | |
396 | ||
397 | case wasm_constant_i32: | |
398 | case wasm_constant_i64: | |
78933a4a | 399 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, true); |
febda64f AM |
400 | if (error) |
401 | return -1; | |
402 | len += bytes_read; | |
403 | prin (stream, " %" PRId64, val); | |
404 | break; | |
405 | ||
406 | case wasm_constant_f32: | |
407 | { | |
408 | double fconstant; | |
409 | int ret; | |
410 | /* This appears to be the best we can do, even though we're | |
411 | using host doubles for WebAssembly floats. */ | |
412 | ret = read_f32 (&fconstant, pc + len, info); | |
413 | if (ret < 0) | |
414 | return -1; | |
415 | len += ret; | |
416 | prin (stream, " %.9g", fconstant); | |
417 | } | |
418 | break; | |
419 | ||
420 | case wasm_constant_f64: | |
421 | { | |
422 | double fconstant; | |
423 | int ret; | |
424 | ret = read_f64 (&fconstant, pc + len, info); | |
425 | if (ret < 0) | |
426 | return -1; | |
427 | len += ret; | |
428 | prin (stream, " %.17g", fconstant); | |
429 | } | |
430 | break; | |
431 | ||
432 | case wasm_call: | |
433 | { | |
434 | uint32_t function_index; | |
435 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, | |
78933a4a | 436 | false); |
febda64f AM |
437 | function_index = val; |
438 | if (error || function_index != val) | |
439 | return -1; | |
440 | len += bytes_read; | |
441 | prin (stream, " "); | |
442 | private_data->section_prefix = ".space.function_index"; | |
443 | (*info->print_address_func) ((bfd_vma) function_index, info); | |
444 | private_data->section_prefix = NULL; | |
445 | } | |
446 | break; | |
447 | ||
448 | case wasm_call_indirect: | |
449 | { | |
450 | uint32_t type_index, xtra_index; | |
451 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, | |
78933a4a | 452 | false); |
febda64f AM |
453 | type_index = val; |
454 | if (error || type_index != val) | |
455 | return -1; | |
456 | len += bytes_read; | |
457 | prin (stream, " %u", type_index); | |
458 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, | |
78933a4a | 459 | false); |
febda64f AM |
460 | xtra_index = val; |
461 | if (error || xtra_index != val) | |
462 | return -1; | |
463 | len += bytes_read; | |
464 | prin (stream, " %u", xtra_index); | |
465 | } | |
466 | break; | |
467 | ||
468 | case wasm_get_local: | |
469 | case wasm_set_local: | |
470 | case wasm_tee_local: | |
471 | { | |
472 | uint32_t local_index; | |
473 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, | |
78933a4a | 474 | false); |
febda64f AM |
475 | local_index = val; |
476 | if (error || local_index != val) | |
477 | return -1; | |
478 | len += bytes_read; | |
479 | prin (stream, " %u", local_index); | |
480 | if (strcmp (op->name + 4, "local") == 0) | |
481 | { | |
482 | static const char *locals[] = | |
483 | { | |
484 | "$dpc", "$sp1", "$r0", "$r1", "$rpc", "$pc0", | |
485 | "$rp", "$fp", "$sp", | |
486 | "$r2", "$r3", "$r4", "$r5", "$r6", "$r7", | |
487 | "$i0", "$i1", "$i2", "$i3", "$i4", "$i5", "$i6", "$i7", | |
488 | "$f0", "$f1", "$f2", "$f3", "$f4", "$f5", "$f6", "$f7", | |
489 | }; | |
490 | if (private_data->print_registers | |
491 | && local_index < ARRAY_SIZE (locals)) | |
492 | prin (stream, " <%s>", locals[local_index]); | |
493 | } | |
494 | else | |
495 | { | |
496 | static const char *globals[] = | |
497 | { | |
498 | "$got", "$plt", "$gpo" | |
499 | }; | |
500 | if (private_data->print_well_known_globals | |
501 | && local_index < ARRAY_SIZE (globals)) | |
502 | prin (stream, " <%s>", globals[local_index]); | |
503 | } | |
504 | } | |
505 | break; | |
506 | ||
507 | case wasm_grow_memory: | |
508 | case wasm_current_memory: | |
509 | { | |
510 | uint32_t reserved_size; | |
511 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, | |
78933a4a | 512 | false); |
febda64f AM |
513 | reserved_size = val; |
514 | if (error || reserved_size != val) | |
515 | return -1; | |
516 | len += bytes_read; | |
517 | prin (stream, " %u", reserved_size); | |
518 | } | |
519 | break; | |
520 | ||
521 | case wasm_load: | |
522 | case wasm_store: | |
523 | { | |
524 | uint32_t flags, offset; | |
525 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, | |
78933a4a | 526 | false); |
febda64f AM |
527 | flags = val; |
528 | if (error || flags != val) | |
529 | return -1; | |
530 | len += bytes_read; | |
531 | val = wasm_read_leb128 (pc + len, info, &error, &bytes_read, | |
78933a4a | 532 | false); |
febda64f AM |
533 | offset = val; |
534 | if (error || offset != val) | |
535 | return -1; | |
536 | len += bytes_read; | |
537 | prin (stream, " a=%u %u", flags, offset); | |
538 | } | |
539 | break; | |
62ecb94c PC |
540 | } |
541 | return len; | |
542 | } | |
543 | ||
544 | /* Print valid disassembler options to STREAM. */ | |
545 | ||
546 | void | |
547 | print_wasm32_disassembler_options (FILE *stream) | |
548 | { | |
549 | unsigned int i, max_len = 0; | |
550 | ||
551 | fprintf (stream, _("\ | |
552 | The following WebAssembly-specific disassembler options are supported for use\n\ | |
553 | with the -M switch:\n")); | |
554 | ||
555 | for (i = 0; i < ARRAY_SIZE (options); i++) | |
556 | { | |
557 | unsigned int len = strlen (options[i].name); | |
558 | ||
559 | if (max_len < len) | |
560 | max_len = len; | |
561 | } | |
562 | ||
563 | for (i = 0, max_len++; i < ARRAY_SIZE (options); i++) | |
564 | fprintf (stream, " %s%*c %s\n", | |
565 | options[i].name, | |
566 | (int)(max_len - strlen (options[i].name)), ' ', | |
567 | _(options[i].description)); | |
568 | } |