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c906108c | 1 | /* Functions for manipulating expressions designed to be executed on the agent |
618f726f | 2 | Copyright (C) 1998-2016 Free Software Foundation, Inc. |
c906108c | 3 | |
c5aa993b | 4 | This file is part of GDB. |
c906108c | 5 | |
c5aa993b JM |
6 | This program is free software; you can redistribute it and/or modify |
7 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 8 | the Free Software Foundation; either version 3 of the License, or |
c5aa993b | 9 | (at your option) any later version. |
c906108c | 10 | |
c5aa993b JM |
11 | This program is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
c906108c | 15 | |
c5aa993b | 16 | You should have received a copy of the GNU General Public License |
a9762ec7 | 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
c906108c | 18 | |
c906108c SS |
19 | /* Despite what the above comment says about this file being part of |
20 | GDB, we would like to keep these functions free of GDB | |
21 | dependencies, since we want to be able to use them in contexts | |
22 | outside of GDB (test suites, the stub, etc.) */ | |
23 | ||
24 | #include "defs.h" | |
25 | #include "ax.h" | |
26 | ||
7a292a7a | 27 | #include "value.h" |
175ff332 HZ |
28 | #include "user-regs.h" |
29 | ||
a14ed312 | 30 | static void grow_expr (struct agent_expr *x, int n); |
392a587b | 31 | |
a14ed312 | 32 | static void append_const (struct agent_expr *x, LONGEST val, int n); |
392a587b | 33 | |
a14ed312 | 34 | static LONGEST read_const (struct agent_expr *x, int o, int n); |
392a587b | 35 | |
a14ed312 | 36 | static void generic_ext (struct agent_expr *x, enum agent_op op, int n); |
c906108c SS |
37 | \f |
38 | /* Functions for building expressions. */ | |
39 | ||
40 | /* Allocate a new, empty agent expression. */ | |
41 | struct agent_expr * | |
35c9c7ba | 42 | new_agent_expr (struct gdbarch *gdbarch, CORE_ADDR scope) |
c906108c | 43 | { |
8d749320 | 44 | struct agent_expr *x = XNEW (struct agent_expr); |
35c9c7ba | 45 | |
c5aa993b | 46 | x->len = 0; |
c906108c SS |
47 | x->size = 1; /* Change this to a larger value once |
48 | reallocation code is tested. */ | |
224c3ddb | 49 | x->buf = (unsigned char *) xmalloc (x->size); |
35c9c7ba SS |
50 | |
51 | x->gdbarch = gdbarch; | |
c906108c SS |
52 | x->scope = scope; |
53 | ||
35c9c7ba SS |
54 | /* Bit vector for registers used. */ |
55 | x->reg_mask_len = 1; | |
224c3ddb | 56 | x->reg_mask = XCNEWVEC (unsigned char, x->reg_mask_len); |
35c9c7ba | 57 | |
92bc6a20 TT |
58 | x->tracing = 0; |
59 | x->trace_string = 0; | |
60 | ||
c906108c SS |
61 | return x; |
62 | } | |
63 | ||
64 | /* Free a agent expression. */ | |
65 | void | |
fba45db2 | 66 | free_agent_expr (struct agent_expr *x) |
c906108c | 67 | { |
b8c9b27d | 68 | xfree (x->buf); |
35c9c7ba | 69 | xfree (x->reg_mask); |
b8c9b27d | 70 | xfree (x); |
c906108c SS |
71 | } |
72 | ||
f23d52e0 AC |
73 | static void |
74 | do_free_agent_expr_cleanup (void *x) | |
75 | { | |
9a3c8263 | 76 | free_agent_expr ((struct agent_expr *) x); |
f23d52e0 AC |
77 | } |
78 | ||
79 | struct cleanup * | |
80 | make_cleanup_free_agent_expr (struct agent_expr *x) | |
81 | { | |
82 | return make_cleanup (do_free_agent_expr_cleanup, x); | |
83 | } | |
84 | ||
c906108c SS |
85 | |
86 | /* Make sure that X has room for at least N more bytes. This doesn't | |
87 | affect the length, just the allocated size. */ | |
88 | static void | |
fba45db2 | 89 | grow_expr (struct agent_expr *x, int n) |
c906108c SS |
90 | { |
91 | if (x->len + n > x->size) | |
92 | { | |
93 | x->size *= 2; | |
94 | if (x->size < x->len + n) | |
95 | x->size = x->len + n + 10; | |
224c3ddb | 96 | x->buf = (unsigned char *) xrealloc (x->buf, x->size); |
c906108c SS |
97 | } |
98 | } | |
99 | ||
100 | ||
101 | /* Append the low N bytes of VAL as an N-byte integer to the | |
102 | expression X, in big-endian order. */ | |
103 | static void | |
fba45db2 | 104 | append_const (struct agent_expr *x, LONGEST val, int n) |
c906108c SS |
105 | { |
106 | int i; | |
107 | ||
108 | grow_expr (x, n); | |
109 | for (i = n - 1; i >= 0; i--) | |
110 | { | |
111 | x->buf[x->len + i] = val & 0xff; | |
112 | val >>= 8; | |
113 | } | |
114 | x->len += n; | |
115 | } | |
116 | ||
117 | ||
118 | /* Extract an N-byte big-endian unsigned integer from expression X at | |
119 | offset O. */ | |
120 | static LONGEST | |
fba45db2 | 121 | read_const (struct agent_expr *x, int o, int n) |
c906108c SS |
122 | { |
123 | int i; | |
124 | LONGEST accum = 0; | |
125 | ||
126 | /* Make sure we're not reading off the end of the expression. */ | |
127 | if (o + n > x->len) | |
3d263c1d | 128 | error (_("GDB bug: ax-general.c (read_const): incomplete constant")); |
c906108c SS |
129 | |
130 | for (i = 0; i < n; i++) | |
131 | accum = (accum << 8) | x->buf[o + i]; | |
c5aa993b | 132 | |
c906108c SS |
133 | return accum; |
134 | } | |
135 | ||
70b8286a SM |
136 | /* See ax.h. */ |
137 | ||
138 | void | |
139 | ax_raw_byte (struct agent_expr *x, gdb_byte byte) | |
140 | { | |
141 | grow_expr (x, 1); | |
142 | x->buf[x->len++] = byte; | |
143 | } | |
c906108c SS |
144 | |
145 | /* Append a simple operator OP to EXPR. */ | |
146 | void | |
fba45db2 | 147 | ax_simple (struct agent_expr *x, enum agent_op op) |
c906108c | 148 | { |
70b8286a | 149 | ax_raw_byte (x, op); |
c906108c SS |
150 | } |
151 | ||
c7f96d2b TT |
152 | /* Append a pick operator to EXPR. DEPTH is the stack item to pick, |
153 | with 0 being top of stack. */ | |
2b52013f | 154 | |
c7f96d2b TT |
155 | void |
156 | ax_pick (struct agent_expr *x, int depth) | |
157 | { | |
158 | if (depth < 0 || depth > 255) | |
159 | error (_("GDB bug: ax-general.c (ax_pick): stack depth out of range")); | |
160 | ax_simple (x, aop_pick); | |
161 | append_const (x, 1, depth); | |
162 | } | |
163 | ||
c906108c SS |
164 | |
165 | /* Append a sign-extension or zero-extension instruction to EXPR, to | |
166 | extend an N-bit value. */ | |
167 | static void | |
fba45db2 | 168 | generic_ext (struct agent_expr *x, enum agent_op op, int n) |
c906108c SS |
169 | { |
170 | /* N must fit in a byte. */ | |
171 | if (n < 0 || n > 255) | |
3d263c1d | 172 | error (_("GDB bug: ax-general.c (generic_ext): bit count out of range")); |
c906108c SS |
173 | /* That had better be enough range. */ |
174 | if (sizeof (LONGEST) * 8 > 255) | |
3e43a32a MS |
175 | error (_("GDB bug: ax-general.c (generic_ext): " |
176 | "opcode has inadequate range")); | |
c906108c SS |
177 | |
178 | grow_expr (x, 2); | |
179 | x->buf[x->len++] = op; | |
180 | x->buf[x->len++] = n; | |
181 | } | |
182 | ||
183 | ||
184 | /* Append a sign-extension instruction to EXPR, to extend an N-bit value. */ | |
185 | void | |
fba45db2 | 186 | ax_ext (struct agent_expr *x, int n) |
c906108c SS |
187 | { |
188 | generic_ext (x, aop_ext, n); | |
189 | } | |
190 | ||
191 | ||
192 | /* Append a zero-extension instruction to EXPR, to extend an N-bit value. */ | |
193 | void | |
fba45db2 | 194 | ax_zero_ext (struct agent_expr *x, int n) |
c906108c SS |
195 | { |
196 | generic_ext (x, aop_zero_ext, n); | |
197 | } | |
198 | ||
199 | ||
200 | /* Append a trace_quick instruction to EXPR, to record N bytes. */ | |
201 | void | |
fba45db2 | 202 | ax_trace_quick (struct agent_expr *x, int n) |
c906108c SS |
203 | { |
204 | /* N must fit in a byte. */ | |
205 | if (n < 0 || n > 255) | |
3e43a32a MS |
206 | error (_("GDB bug: ax-general.c (ax_trace_quick): " |
207 | "size out of range for trace_quick")); | |
c906108c SS |
208 | |
209 | grow_expr (x, 2); | |
210 | x->buf[x->len++] = aop_trace_quick; | |
211 | x->buf[x->len++] = n; | |
212 | } | |
213 | ||
214 | ||
215 | /* Append a goto op to EXPR. OP is the actual op (must be aop_goto or | |
216 | aop_if_goto). We assume we don't know the target offset yet, | |
217 | because it's probably a forward branch, so we leave space in EXPR | |
218 | for the target, and return the offset in EXPR of that space, so we | |
219 | can backpatch it once we do know the target offset. Use ax_label | |
220 | to do the backpatching. */ | |
c5aa993b | 221 | int |
fba45db2 | 222 | ax_goto (struct agent_expr *x, enum agent_op op) |
c906108c SS |
223 | { |
224 | grow_expr (x, 3); | |
225 | x->buf[x->len + 0] = op; | |
226 | x->buf[x->len + 1] = 0xff; | |
227 | x->buf[x->len + 2] = 0xff; | |
228 | x->len += 3; | |
229 | return x->len - 2; | |
230 | } | |
231 | ||
232 | /* Suppose a given call to ax_goto returns some value PATCH. When you | |
233 | know the offset TARGET that goto should jump to, call | |
c5aa993b | 234 | ax_label (EXPR, PATCH, TARGET) |
c906108c SS |
235 | to patch TARGET into the ax_goto instruction. */ |
236 | void | |
fba45db2 | 237 | ax_label (struct agent_expr *x, int patch, int target) |
c906108c SS |
238 | { |
239 | /* Make sure the value is in range. Don't accept 0xffff as an | |
240 | offset; that's our magic sentinel value for unpatched branches. */ | |
241 | if (target < 0 || target >= 0xffff) | |
3d263c1d | 242 | error (_("GDB bug: ax-general.c (ax_label): label target out of range")); |
c5aa993b | 243 | |
c906108c SS |
244 | x->buf[patch] = (target >> 8) & 0xff; |
245 | x->buf[patch + 1] = target & 0xff; | |
246 | } | |
247 | ||
248 | ||
249 | /* Assemble code to push a constant on the stack. */ | |
250 | void | |
fba45db2 | 251 | ax_const_l (struct agent_expr *x, LONGEST l) |
c906108c SS |
252 | { |
253 | static enum agent_op ops[] | |
c5aa993b JM |
254 | = |
255 | {aop_const8, aop_const16, aop_const32, aop_const64}; | |
c906108c SS |
256 | int size; |
257 | int op; | |
258 | ||
259 | /* How big is the number? 'op' keeps track of which opcode to use. | |
260 | Notice that we don't really care whether the original number was | |
261 | signed or unsigned; we always reproduce the value exactly, and | |
262 | use the shortest representation. */ | |
263 | for (op = 0, size = 8; size < 64; size *= 2, op++) | |
44a81774 | 264 | { |
cf3e25ca | 265 | LONGEST lim = ((LONGEST) 1) << (size - 1); |
44a81774 JB |
266 | |
267 | if (-lim <= l && l <= lim - 1) | |
268 | break; | |
269 | } | |
c906108c | 270 | |
0e2de366 | 271 | /* Emit the right opcode... */ |
c906108c SS |
272 | ax_simple (x, ops[op]); |
273 | ||
274 | /* Emit the low SIZE bytes as an unsigned number. We know that | |
275 | sign-extending this will yield l. */ | |
276 | append_const (x, l, size / 8); | |
277 | ||
278 | /* Now, if it was negative, and not full-sized, sign-extend it. */ | |
279 | if (l < 0 && size < 64) | |
280 | ax_ext (x, size); | |
281 | } | |
282 | ||
283 | ||
284 | void | |
fba45db2 | 285 | ax_const_d (struct agent_expr *x, LONGEST d) |
c906108c SS |
286 | { |
287 | /* FIXME: floating-point support not present yet. */ | |
3e43a32a MS |
288 | error (_("GDB bug: ax-general.c (ax_const_d): " |
289 | "floating point not supported yet")); | |
c906108c SS |
290 | } |
291 | ||
292 | ||
293 | /* Assemble code to push the value of register number REG on the | |
294 | stack. */ | |
c5aa993b | 295 | void |
fba45db2 | 296 | ax_reg (struct agent_expr *x, int reg) |
c906108c | 297 | { |
175ff332 HZ |
298 | if (reg >= gdbarch_num_regs (x->gdbarch)) |
299 | { | |
300 | /* This is a pseudo-register. */ | |
301 | if (!gdbarch_ax_pseudo_register_push_stack_p (x->gdbarch)) | |
302 | error (_("'%s' is a pseudo-register; " | |
303 | "GDB cannot yet trace its contents."), | |
304 | user_reg_map_regnum_to_name (x->gdbarch, reg)); | |
305 | if (gdbarch_ax_pseudo_register_push_stack (x->gdbarch, x, reg)) | |
306 | error (_("Trace '%s' failed."), | |
307 | user_reg_map_regnum_to_name (x->gdbarch, reg)); | |
308 | } | |
309 | else | |
310 | { | |
311 | /* Make sure the register number is in range. */ | |
312 | if (reg < 0 || reg > 0xffff) | |
3e43a32a MS |
313 | error (_("GDB bug: ax-general.c (ax_reg): " |
314 | "register number out of range")); | |
175ff332 HZ |
315 | grow_expr (x, 3); |
316 | x->buf[x->len] = aop_reg; | |
317 | x->buf[x->len + 1] = (reg >> 8) & 0xff; | |
318 | x->buf[x->len + 2] = (reg) & 0xff; | |
319 | x->len += 3; | |
320 | } | |
c906108c | 321 | } |
f61e138d SS |
322 | |
323 | /* Assemble code to operate on a trace state variable. */ | |
324 | ||
325 | void | |
326 | ax_tsv (struct agent_expr *x, enum agent_op op, int num) | |
327 | { | |
328 | /* Make sure the tsv number is in range. */ | |
329 | if (num < 0 || num > 0xffff) | |
3e43a32a MS |
330 | internal_error (__FILE__, __LINE__, |
331 | _("ax-general.c (ax_tsv): variable " | |
332 | "number is %d, out of range"), num); | |
f61e138d SS |
333 | |
334 | grow_expr (x, 3); | |
335 | x->buf[x->len] = op; | |
336 | x->buf[x->len + 1] = (num >> 8) & 0xff; | |
337 | x->buf[x->len + 2] = (num) & 0xff; | |
338 | x->len += 3; | |
339 | } | |
d3ce09f5 SS |
340 | |
341 | /* Append a string to the expression. Note that the string is going | |
342 | into the bytecodes directly, not on the stack. As a precaution, | |
343 | include both length as prefix, and terminate with a NUL. (The NUL | |
344 | is counted in the length.) */ | |
345 | ||
346 | void | |
741d92cf | 347 | ax_string (struct agent_expr *x, const char *str, int slen) |
d3ce09f5 SS |
348 | { |
349 | int i; | |
350 | ||
351 | /* Make sure the string length is reasonable. */ | |
352 | if (slen < 0 || slen > 0xffff) | |
353 | internal_error (__FILE__, __LINE__, | |
354 | _("ax-general.c (ax_string): string " | |
355 | "length is %d, out of allowed range"), slen); | |
356 | ||
357 | grow_expr (x, 2 + slen + 1); | |
358 | x->buf[x->len++] = ((slen + 1) >> 8) & 0xff; | |
359 | x->buf[x->len++] = (slen + 1) & 0xff; | |
360 | for (i = 0; i < slen; ++i) | |
361 | x->buf[x->len++] = str[i]; | |
362 | x->buf[x->len++] = '\0'; | |
363 | } | |
c5aa993b | 364 | \f |
c906108c SS |
365 | |
366 | ||
c906108c SS |
367 | /* Functions for disassembling agent expressions, and otherwise |
368 | debugging the expression compiler. */ | |
369 | ||
c5aa993b JM |
370 | struct aop_map aop_map[] = |
371 | { | |
94d5e490 TT |
372 | {0, 0, 0, 0, 0} |
373 | #define DEFOP(NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED, VALUE) \ | |
374 | , { # NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED } | |
375 | #include "ax.def" | |
376 | #undef DEFOP | |
c906108c SS |
377 | }; |
378 | ||
379 | ||
380 | /* Disassemble the expression EXPR, writing to F. */ | |
381 | void | |
fba45db2 | 382 | ax_print (struct ui_file *f, struct agent_expr *x) |
c906108c SS |
383 | { |
384 | int i; | |
c906108c | 385 | |
35c9c7ba SS |
386 | fprintf_filtered (f, _("Scope: %s\n"), paddress (x->gdbarch, x->scope)); |
387 | fprintf_filtered (f, _("Reg mask:")); | |
388 | for (i = 0; i < x->reg_mask_len; ++i) | |
389 | fprintf_filtered (f, _(" %02x"), x->reg_mask[i]); | |
390 | fprintf_filtered (f, _("\n")); | |
391 | ||
c906108c SS |
392 | /* Check the size of the name array against the number of entries in |
393 | the enum, to catch additions that people didn't sync. */ | |
394 | if ((sizeof (aop_map) / sizeof (aop_map[0])) | |
395 | != aop_last) | |
3d263c1d | 396 | error (_("GDB bug: ax-general.c (ax_print): opcode map out of sync")); |
c5aa993b JM |
397 | |
398 | for (i = 0; i < x->len;) | |
c906108c | 399 | { |
aead7601 | 400 | enum agent_op op = (enum agent_op) x->buf[i]; |
c906108c SS |
401 | |
402 | if (op >= (sizeof (aop_map) / sizeof (aop_map[0])) | |
c5aa993b | 403 | || !aop_map[op].name) |
c906108c | 404 | { |
3d263c1d | 405 | fprintf_filtered (f, _("%3d <bad opcode %02x>\n"), i, op); |
c906108c SS |
406 | i++; |
407 | continue; | |
408 | } | |
a04b0428 | 409 | if (i + 1 + aop_map[op].op_size > x->len) |
c906108c | 410 | { |
3d263c1d | 411 | fprintf_filtered (f, _("%3d <incomplete opcode %s>\n"), |
c906108c SS |
412 | i, aop_map[op].name); |
413 | break; | |
414 | } | |
415 | ||
416 | fprintf_filtered (f, "%3d %s", i, aop_map[op].name); | |
a04b0428 | 417 | if (aop_map[op].op_size > 0) |
c906108c SS |
418 | { |
419 | fputs_filtered (" ", f); | |
c5aa993b | 420 | |
c906108c | 421 | print_longest (f, 'd', 0, |
a04b0428 | 422 | read_const (x, i + 1, aop_map[op].op_size)); |
c906108c | 423 | } |
d3ce09f5 SS |
424 | /* Handle the complicated printf arguments specially. */ |
425 | else if (op == aop_printf) | |
426 | { | |
427 | int slen, nargs; | |
428 | ||
429 | i++; | |
430 | nargs = x->buf[i++]; | |
431 | slen = x->buf[i++]; | |
432 | slen = slen * 256 + x->buf[i++]; | |
433 | fprintf_filtered (f, _(" \"%s\", %d args"), | |
434 | &(x->buf[i]), nargs); | |
435 | i += slen - 1; | |
436 | } | |
c906108c | 437 | fprintf_filtered (f, "\n"); |
a04b0428 | 438 | i += 1 + aop_map[op].op_size; |
c906108c SS |
439 | } |
440 | } | |
441 | ||
35c9c7ba SS |
442 | /* Add register REG to the register mask for expression AX. */ |
443 | void | |
444 | ax_reg_mask (struct agent_expr *ax, int reg) | |
445 | { | |
175ff332 | 446 | if (reg >= gdbarch_num_regs (ax->gdbarch)) |
35c9c7ba | 447 | { |
175ff332 HZ |
448 | /* This is a pseudo-register. */ |
449 | if (!gdbarch_ax_pseudo_register_collect_p (ax->gdbarch)) | |
450 | error (_("'%s' is a pseudo-register; " | |
451 | "GDB cannot yet trace its contents."), | |
452 | user_reg_map_regnum_to_name (ax->gdbarch, reg)); | |
453 | if (gdbarch_ax_pseudo_register_collect (ax->gdbarch, ax, reg)) | |
454 | error (_("Trace '%s' failed."), | |
455 | user_reg_map_regnum_to_name (ax->gdbarch, reg)); | |
456 | } | |
457 | else | |
458 | { | |
459 | int byte = reg / 8; | |
460 | ||
461 | /* Grow the bit mask if necessary. */ | |
462 | if (byte >= ax->reg_mask_len) | |
463 | { | |
464 | /* It's not appropriate to double here. This isn't a | |
465 | string buffer. */ | |
466 | int new_len = byte + 1; | |
224c3ddb SM |
467 | unsigned char *new_reg_mask |
468 | = XRESIZEVEC (unsigned char, ax->reg_mask, new_len); | |
469 | ||
175ff332 HZ |
470 | memset (new_reg_mask + ax->reg_mask_len, 0, |
471 | (new_len - ax->reg_mask_len) * sizeof (ax->reg_mask[0])); | |
472 | ax->reg_mask_len = new_len; | |
473 | ax->reg_mask = new_reg_mask; | |
474 | } | |
475 | ||
476 | ax->reg_mask[byte] |= 1 << (reg % 8); | |
35c9c7ba | 477 | } |
35c9c7ba SS |
478 | } |
479 | ||
480 | /* Given an agent expression AX, fill in requirements and other descriptive | |
481 | bits. */ | |
c906108c | 482 | void |
35c9c7ba | 483 | ax_reqs (struct agent_expr *ax) |
c906108c SS |
484 | { |
485 | int i; | |
486 | int height; | |
487 | ||
3d269a59 JB |
488 | /* Jump target table. targets[i] is non-zero iff we have found a |
489 | jump to offset i. */ | |
c906108c SS |
490 | char *targets = (char *) alloca (ax->len * sizeof (targets[0])); |
491 | ||
3d269a59 JB |
492 | /* Instruction boundary table. boundary[i] is non-zero iff our scan |
493 | has reached an instruction starting at offset i. */ | |
c906108c SS |
494 | char *boundary = (char *) alloca (ax->len * sizeof (boundary[0])); |
495 | ||
3d269a59 | 496 | /* Stack height record. If either targets[i] or boundary[i] is |
c906108c SS |
497 | non-zero, heights[i] is the height the stack should have before |
498 | executing the bytecode at that point. */ | |
499 | int *heights = (int *) alloca (ax->len * sizeof (heights[0])); | |
500 | ||
501 | /* Pointer to a description of the present op. */ | |
502 | struct aop_map *op; | |
503 | ||
c906108c SS |
504 | memset (targets, 0, ax->len * sizeof (targets[0])); |
505 | memset (boundary, 0, ax->len * sizeof (boundary[0])); | |
506 | ||
35c9c7ba SS |
507 | ax->max_height = ax->min_height = height = 0; |
508 | ax->flaw = agent_flaw_none; | |
509 | ax->max_data_size = 0; | |
c906108c | 510 | |
a04b0428 | 511 | for (i = 0; i < ax->len; i += 1 + op->op_size) |
c906108c SS |
512 | { |
513 | if (ax->buf[i] > (sizeof (aop_map) / sizeof (aop_map[0]))) | |
514 | { | |
35c9c7ba | 515 | ax->flaw = agent_flaw_bad_instruction; |
c906108c SS |
516 | return; |
517 | } | |
518 | ||
519 | op = &aop_map[ax->buf[i]]; | |
520 | ||
c5aa993b | 521 | if (!op->name) |
c906108c | 522 | { |
35c9c7ba | 523 | ax->flaw = agent_flaw_bad_instruction; |
c906108c SS |
524 | return; |
525 | } | |
c5aa993b | 526 | |
a04b0428 | 527 | if (i + 1 + op->op_size > ax->len) |
c906108c | 528 | { |
35c9c7ba | 529 | ax->flaw = agent_flaw_incomplete_instruction; |
c906108c SS |
530 | return; |
531 | } | |
532 | ||
3d269a59 JB |
533 | /* If this instruction is a forward jump target, does the |
534 | current stack height match the stack height at the jump | |
535 | source? */ | |
c906108c SS |
536 | if (targets[i] && (heights[i] != height)) |
537 | { | |
35c9c7ba | 538 | ax->flaw = agent_flaw_height_mismatch; |
c906108c SS |
539 | return; |
540 | } | |
541 | ||
542 | boundary[i] = 1; | |
543 | heights[i] = height; | |
544 | ||
a04b0428 | 545 | height -= op->consumed; |
35c9c7ba SS |
546 | if (height < ax->min_height) |
547 | ax->min_height = height; | |
c906108c | 548 | height += op->produced; |
35c9c7ba SS |
549 | if (height > ax->max_height) |
550 | ax->max_height = height; | |
c906108c | 551 | |
35c9c7ba SS |
552 | if (op->data_size > ax->max_data_size) |
553 | ax->max_data_size = op->data_size; | |
c906108c SS |
554 | |
555 | /* For jump instructions, check that the target is a valid | |
c5aa993b JM |
556 | offset. If it is, record the fact that that location is a |
557 | jump target, and record the height we expect there. */ | |
c906108c SS |
558 | if (aop_goto == op - aop_map |
559 | || aop_if_goto == op - aop_map) | |
560 | { | |
561 | int target = read_const (ax, i + 1, 2); | |
562 | if (target < 0 || target >= ax->len) | |
563 | { | |
35c9c7ba | 564 | ax->flaw = agent_flaw_bad_jump; |
c906108c SS |
565 | return; |
566 | } | |
3d269a59 JB |
567 | |
568 | /* Do we have any information about what the stack height | |
569 | should be at the target? */ | |
570 | if (targets[target] || boundary[target]) | |
c906108c | 571 | { |
3d269a59 | 572 | if (heights[target] != height) |
c906108c | 573 | { |
35c9c7ba | 574 | ax->flaw = agent_flaw_height_mismatch; |
c906108c SS |
575 | return; |
576 | } | |
577 | } | |
3d269a59 JB |
578 | |
579 | /* Record the target, along with the stack height we expect. */ | |
580 | targets[target] = 1; | |
581 | heights[target] = height; | |
c906108c | 582 | } |
c5aa993b | 583 | |
c906108c SS |
584 | /* For unconditional jumps with a successor, check that the |
585 | successor is a target, and pick up its stack height. */ | |
586 | if (aop_goto == op - aop_map | |
587 | && i + 3 < ax->len) | |
588 | { | |
c5aa993b | 589 | if (!targets[i + 3]) |
c906108c | 590 | { |
35c9c7ba | 591 | ax->flaw = agent_flaw_hole; |
c906108c SS |
592 | return; |
593 | } | |
594 | ||
595 | height = heights[i + 3]; | |
596 | } | |
597 | ||
598 | /* For reg instructions, record the register in the bit mask. */ | |
599 | if (aop_reg == op - aop_map) | |
600 | { | |
601 | int reg = read_const (ax, i + 1, 2); | |
c906108c | 602 | |
35c9c7ba | 603 | ax_reg_mask (ax, reg); |
c906108c SS |
604 | } |
605 | } | |
606 | ||
607 | /* Check that all the targets are on boundaries. */ | |
608 | for (i = 0; i < ax->len; i++) | |
609 | if (targets[i] && !boundary[i]) | |
610 | { | |
35c9c7ba | 611 | ax->flaw = agent_flaw_bad_jump; |
c906108c SS |
612 | return; |
613 | } | |
614 | ||
35c9c7ba | 615 | ax->final_height = height; |
c906108c | 616 | } |