Commit | Line | Data |
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c906108c | 1 | /* Functions for manipulating expressions designed to be executed on the agent |
28e7fd62 | 2 | Copyright (C) 1998-2013 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" |
0e9f083f | 28 | #include <string.h> |
7a292a7a | 29 | |
175ff332 HZ |
30 | #include "user-regs.h" |
31 | ||
a14ed312 | 32 | static void grow_expr (struct agent_expr *x, int n); |
392a587b | 33 | |
a14ed312 | 34 | static void append_const (struct agent_expr *x, LONGEST val, int n); |
392a587b | 35 | |
a14ed312 | 36 | static LONGEST read_const (struct agent_expr *x, int o, int n); |
392a587b | 37 | |
a14ed312 | 38 | static void generic_ext (struct agent_expr *x, enum agent_op op, int n); |
c906108c SS |
39 | \f |
40 | /* Functions for building expressions. */ | |
41 | ||
42 | /* Allocate a new, empty agent expression. */ | |
43 | struct agent_expr * | |
35c9c7ba | 44 | new_agent_expr (struct gdbarch *gdbarch, CORE_ADDR scope) |
c906108c SS |
45 | { |
46 | struct agent_expr *x = xmalloc (sizeof (*x)); | |
35c9c7ba | 47 | |
c5aa993b | 48 | x->len = 0; |
c906108c SS |
49 | x->size = 1; /* Change this to a larger value once |
50 | reallocation code is tested. */ | |
c5aa993b | 51 | x->buf = xmalloc (x->size); |
35c9c7ba SS |
52 | |
53 | x->gdbarch = gdbarch; | |
c906108c SS |
54 | x->scope = scope; |
55 | ||
35c9c7ba SS |
56 | /* Bit vector for registers used. */ |
57 | x->reg_mask_len = 1; | |
58 | x->reg_mask = xmalloc (x->reg_mask_len * sizeof (x->reg_mask[0])); | |
59 | memset (x->reg_mask, 0, x->reg_mask_len * sizeof (x->reg_mask[0])); | |
60 | ||
92bc6a20 TT |
61 | x->tracing = 0; |
62 | x->trace_string = 0; | |
63 | ||
c906108c SS |
64 | return x; |
65 | } | |
66 | ||
67 | /* Free a agent expression. */ | |
68 | void | |
fba45db2 | 69 | free_agent_expr (struct agent_expr *x) |
c906108c | 70 | { |
b8c9b27d | 71 | xfree (x->buf); |
35c9c7ba | 72 | xfree (x->reg_mask); |
b8c9b27d | 73 | xfree (x); |
c906108c SS |
74 | } |
75 | ||
f23d52e0 AC |
76 | static void |
77 | do_free_agent_expr_cleanup (void *x) | |
78 | { | |
79 | free_agent_expr (x); | |
80 | } | |
81 | ||
82 | struct cleanup * | |
83 | make_cleanup_free_agent_expr (struct agent_expr *x) | |
84 | { | |
85 | return make_cleanup (do_free_agent_expr_cleanup, x); | |
86 | } | |
87 | ||
c906108c SS |
88 | |
89 | /* Make sure that X has room for at least N more bytes. This doesn't | |
90 | affect the length, just the allocated size. */ | |
91 | static void | |
fba45db2 | 92 | grow_expr (struct agent_expr *x, int n) |
c906108c SS |
93 | { |
94 | if (x->len + n > x->size) | |
95 | { | |
96 | x->size *= 2; | |
97 | if (x->size < x->len + n) | |
98 | x->size = x->len + n + 10; | |
99 | x->buf = xrealloc (x->buf, x->size); | |
100 | } | |
101 | } | |
102 | ||
103 | ||
104 | /* Append the low N bytes of VAL as an N-byte integer to the | |
105 | expression X, in big-endian order. */ | |
106 | static void | |
fba45db2 | 107 | append_const (struct agent_expr *x, LONGEST val, int n) |
c906108c SS |
108 | { |
109 | int i; | |
110 | ||
111 | grow_expr (x, n); | |
112 | for (i = n - 1; i >= 0; i--) | |
113 | { | |
114 | x->buf[x->len + i] = val & 0xff; | |
115 | val >>= 8; | |
116 | } | |
117 | x->len += n; | |
118 | } | |
119 | ||
120 | ||
121 | /* Extract an N-byte big-endian unsigned integer from expression X at | |
122 | offset O. */ | |
123 | static LONGEST | |
fba45db2 | 124 | read_const (struct agent_expr *x, int o, int n) |
c906108c SS |
125 | { |
126 | int i; | |
127 | LONGEST accum = 0; | |
128 | ||
129 | /* Make sure we're not reading off the end of the expression. */ | |
130 | if (o + n > x->len) | |
3d263c1d | 131 | error (_("GDB bug: ax-general.c (read_const): incomplete constant")); |
c906108c SS |
132 | |
133 | for (i = 0; i < n; i++) | |
134 | accum = (accum << 8) | x->buf[o + i]; | |
c5aa993b | 135 | |
c906108c SS |
136 | return accum; |
137 | } | |
138 | ||
139 | ||
140 | /* Append a simple operator OP to EXPR. */ | |
141 | void | |
fba45db2 | 142 | ax_simple (struct agent_expr *x, enum agent_op op) |
c906108c SS |
143 | { |
144 | grow_expr (x, 1); | |
145 | x->buf[x->len++] = op; | |
146 | } | |
147 | ||
c7f96d2b TT |
148 | /* Append a pick operator to EXPR. DEPTH is the stack item to pick, |
149 | with 0 being top of stack. */ | |
2b52013f | 150 | |
c7f96d2b TT |
151 | void |
152 | ax_pick (struct agent_expr *x, int depth) | |
153 | { | |
154 | if (depth < 0 || depth > 255) | |
155 | error (_("GDB bug: ax-general.c (ax_pick): stack depth out of range")); | |
156 | ax_simple (x, aop_pick); | |
157 | append_const (x, 1, depth); | |
158 | } | |
159 | ||
c906108c SS |
160 | |
161 | /* Append a sign-extension or zero-extension instruction to EXPR, to | |
162 | extend an N-bit value. */ | |
163 | static void | |
fba45db2 | 164 | generic_ext (struct agent_expr *x, enum agent_op op, int n) |
c906108c SS |
165 | { |
166 | /* N must fit in a byte. */ | |
167 | if (n < 0 || n > 255) | |
3d263c1d | 168 | error (_("GDB bug: ax-general.c (generic_ext): bit count out of range")); |
c906108c SS |
169 | /* That had better be enough range. */ |
170 | if (sizeof (LONGEST) * 8 > 255) | |
3e43a32a MS |
171 | error (_("GDB bug: ax-general.c (generic_ext): " |
172 | "opcode has inadequate range")); | |
c906108c SS |
173 | |
174 | grow_expr (x, 2); | |
175 | x->buf[x->len++] = op; | |
176 | x->buf[x->len++] = n; | |
177 | } | |
178 | ||
179 | ||
180 | /* Append a sign-extension instruction to EXPR, to extend an N-bit value. */ | |
181 | void | |
fba45db2 | 182 | ax_ext (struct agent_expr *x, int n) |
c906108c SS |
183 | { |
184 | generic_ext (x, aop_ext, n); | |
185 | } | |
186 | ||
187 | ||
188 | /* Append a zero-extension instruction to EXPR, to extend an N-bit value. */ | |
189 | void | |
fba45db2 | 190 | ax_zero_ext (struct agent_expr *x, int n) |
c906108c SS |
191 | { |
192 | generic_ext (x, aop_zero_ext, n); | |
193 | } | |
194 | ||
195 | ||
196 | /* Append a trace_quick instruction to EXPR, to record N bytes. */ | |
197 | void | |
fba45db2 | 198 | ax_trace_quick (struct agent_expr *x, int n) |
c906108c SS |
199 | { |
200 | /* N must fit in a byte. */ | |
201 | if (n < 0 || n > 255) | |
3e43a32a MS |
202 | error (_("GDB bug: ax-general.c (ax_trace_quick): " |
203 | "size out of range for trace_quick")); | |
c906108c SS |
204 | |
205 | grow_expr (x, 2); | |
206 | x->buf[x->len++] = aop_trace_quick; | |
207 | x->buf[x->len++] = n; | |
208 | } | |
209 | ||
210 | ||
211 | /* Append a goto op to EXPR. OP is the actual op (must be aop_goto or | |
212 | aop_if_goto). We assume we don't know the target offset yet, | |
213 | because it's probably a forward branch, so we leave space in EXPR | |
214 | for the target, and return the offset in EXPR of that space, so we | |
215 | can backpatch it once we do know the target offset. Use ax_label | |
216 | to do the backpatching. */ | |
c5aa993b | 217 | int |
fba45db2 | 218 | ax_goto (struct agent_expr *x, enum agent_op op) |
c906108c SS |
219 | { |
220 | grow_expr (x, 3); | |
221 | x->buf[x->len + 0] = op; | |
222 | x->buf[x->len + 1] = 0xff; | |
223 | x->buf[x->len + 2] = 0xff; | |
224 | x->len += 3; | |
225 | return x->len - 2; | |
226 | } | |
227 | ||
228 | /* Suppose a given call to ax_goto returns some value PATCH. When you | |
229 | know the offset TARGET that goto should jump to, call | |
c5aa993b | 230 | ax_label (EXPR, PATCH, TARGET) |
c906108c SS |
231 | to patch TARGET into the ax_goto instruction. */ |
232 | void | |
fba45db2 | 233 | ax_label (struct agent_expr *x, int patch, int target) |
c906108c SS |
234 | { |
235 | /* Make sure the value is in range. Don't accept 0xffff as an | |
236 | offset; that's our magic sentinel value for unpatched branches. */ | |
237 | if (target < 0 || target >= 0xffff) | |
3d263c1d | 238 | error (_("GDB bug: ax-general.c (ax_label): label target out of range")); |
c5aa993b | 239 | |
c906108c SS |
240 | x->buf[patch] = (target >> 8) & 0xff; |
241 | x->buf[patch + 1] = target & 0xff; | |
242 | } | |
243 | ||
244 | ||
245 | /* Assemble code to push a constant on the stack. */ | |
246 | void | |
fba45db2 | 247 | ax_const_l (struct agent_expr *x, LONGEST l) |
c906108c SS |
248 | { |
249 | static enum agent_op ops[] | |
c5aa993b JM |
250 | = |
251 | {aop_const8, aop_const16, aop_const32, aop_const64}; | |
c906108c SS |
252 | int size; |
253 | int op; | |
254 | ||
255 | /* How big is the number? 'op' keeps track of which opcode to use. | |
256 | Notice that we don't really care whether the original number was | |
257 | signed or unsigned; we always reproduce the value exactly, and | |
258 | use the shortest representation. */ | |
259 | for (op = 0, size = 8; size < 64; size *= 2, op++) | |
44a81774 | 260 | { |
cf3e25ca | 261 | LONGEST lim = ((LONGEST) 1) << (size - 1); |
44a81774 JB |
262 | |
263 | if (-lim <= l && l <= lim - 1) | |
264 | break; | |
265 | } | |
c906108c | 266 | |
0e2de366 | 267 | /* Emit the right opcode... */ |
c906108c SS |
268 | ax_simple (x, ops[op]); |
269 | ||
270 | /* Emit the low SIZE bytes as an unsigned number. We know that | |
271 | sign-extending this will yield l. */ | |
272 | append_const (x, l, size / 8); | |
273 | ||
274 | /* Now, if it was negative, and not full-sized, sign-extend it. */ | |
275 | if (l < 0 && size < 64) | |
276 | ax_ext (x, size); | |
277 | } | |
278 | ||
279 | ||
280 | void | |
fba45db2 | 281 | ax_const_d (struct agent_expr *x, LONGEST d) |
c906108c SS |
282 | { |
283 | /* FIXME: floating-point support not present yet. */ | |
3e43a32a MS |
284 | error (_("GDB bug: ax-general.c (ax_const_d): " |
285 | "floating point not supported yet")); | |
c906108c SS |
286 | } |
287 | ||
288 | ||
289 | /* Assemble code to push the value of register number REG on the | |
290 | stack. */ | |
c5aa993b | 291 | void |
fba45db2 | 292 | ax_reg (struct agent_expr *x, int reg) |
c906108c | 293 | { |
175ff332 HZ |
294 | if (reg >= gdbarch_num_regs (x->gdbarch)) |
295 | { | |
296 | /* This is a pseudo-register. */ | |
297 | if (!gdbarch_ax_pseudo_register_push_stack_p (x->gdbarch)) | |
298 | error (_("'%s' is a pseudo-register; " | |
299 | "GDB cannot yet trace its contents."), | |
300 | user_reg_map_regnum_to_name (x->gdbarch, reg)); | |
301 | if (gdbarch_ax_pseudo_register_push_stack (x->gdbarch, x, reg)) | |
302 | error (_("Trace '%s' failed."), | |
303 | user_reg_map_regnum_to_name (x->gdbarch, reg)); | |
304 | } | |
305 | else | |
306 | { | |
307 | /* Make sure the register number is in range. */ | |
308 | if (reg < 0 || reg > 0xffff) | |
3e43a32a MS |
309 | error (_("GDB bug: ax-general.c (ax_reg): " |
310 | "register number out of range")); | |
175ff332 HZ |
311 | grow_expr (x, 3); |
312 | x->buf[x->len] = aop_reg; | |
313 | x->buf[x->len + 1] = (reg >> 8) & 0xff; | |
314 | x->buf[x->len + 2] = (reg) & 0xff; | |
315 | x->len += 3; | |
316 | } | |
c906108c | 317 | } |
f61e138d SS |
318 | |
319 | /* Assemble code to operate on a trace state variable. */ | |
320 | ||
321 | void | |
322 | ax_tsv (struct agent_expr *x, enum agent_op op, int num) | |
323 | { | |
324 | /* Make sure the tsv number is in range. */ | |
325 | if (num < 0 || num > 0xffff) | |
3e43a32a MS |
326 | internal_error (__FILE__, __LINE__, |
327 | _("ax-general.c (ax_tsv): variable " | |
328 | "number is %d, out of range"), num); | |
f61e138d SS |
329 | |
330 | grow_expr (x, 3); | |
331 | x->buf[x->len] = op; | |
332 | x->buf[x->len + 1] = (num >> 8) & 0xff; | |
333 | x->buf[x->len + 2] = (num) & 0xff; | |
334 | x->len += 3; | |
335 | } | |
d3ce09f5 SS |
336 | |
337 | /* Append a string to the expression. Note that the string is going | |
338 | into the bytecodes directly, not on the stack. As a precaution, | |
339 | include both length as prefix, and terminate with a NUL. (The NUL | |
340 | is counted in the length.) */ | |
341 | ||
342 | void | |
741d92cf | 343 | ax_string (struct agent_expr *x, const char *str, int slen) |
d3ce09f5 SS |
344 | { |
345 | int i; | |
346 | ||
347 | /* Make sure the string length is reasonable. */ | |
348 | if (slen < 0 || slen > 0xffff) | |
349 | internal_error (__FILE__, __LINE__, | |
350 | _("ax-general.c (ax_string): string " | |
351 | "length is %d, out of allowed range"), slen); | |
352 | ||
353 | grow_expr (x, 2 + slen + 1); | |
354 | x->buf[x->len++] = ((slen + 1) >> 8) & 0xff; | |
355 | x->buf[x->len++] = (slen + 1) & 0xff; | |
356 | for (i = 0; i < slen; ++i) | |
357 | x->buf[x->len++] = str[i]; | |
358 | x->buf[x->len++] = '\0'; | |
359 | } | |
c5aa993b | 360 | \f |
c906108c SS |
361 | |
362 | ||
c906108c SS |
363 | /* Functions for disassembling agent expressions, and otherwise |
364 | debugging the expression compiler. */ | |
365 | ||
c5aa993b JM |
366 | struct aop_map aop_map[] = |
367 | { | |
94d5e490 TT |
368 | {0, 0, 0, 0, 0} |
369 | #define DEFOP(NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED, VALUE) \ | |
370 | , { # NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED } | |
371 | #include "ax.def" | |
372 | #undef DEFOP | |
c906108c SS |
373 | }; |
374 | ||
375 | ||
376 | /* Disassemble the expression EXPR, writing to F. */ | |
377 | void | |
fba45db2 | 378 | ax_print (struct ui_file *f, struct agent_expr *x) |
c906108c SS |
379 | { |
380 | int i; | |
c906108c | 381 | |
35c9c7ba SS |
382 | fprintf_filtered (f, _("Scope: %s\n"), paddress (x->gdbarch, x->scope)); |
383 | fprintf_filtered (f, _("Reg mask:")); | |
384 | for (i = 0; i < x->reg_mask_len; ++i) | |
385 | fprintf_filtered (f, _(" %02x"), x->reg_mask[i]); | |
386 | fprintf_filtered (f, _("\n")); | |
387 | ||
c906108c SS |
388 | /* Check the size of the name array against the number of entries in |
389 | the enum, to catch additions that people didn't sync. */ | |
390 | if ((sizeof (aop_map) / sizeof (aop_map[0])) | |
391 | != aop_last) | |
3d263c1d | 392 | error (_("GDB bug: ax-general.c (ax_print): opcode map out of sync")); |
c5aa993b JM |
393 | |
394 | for (i = 0; i < x->len;) | |
c906108c SS |
395 | { |
396 | enum agent_op op = x->buf[i]; | |
397 | ||
398 | if (op >= (sizeof (aop_map) / sizeof (aop_map[0])) | |
c5aa993b | 399 | || !aop_map[op].name) |
c906108c | 400 | { |
3d263c1d | 401 | fprintf_filtered (f, _("%3d <bad opcode %02x>\n"), i, op); |
c906108c SS |
402 | i++; |
403 | continue; | |
404 | } | |
a04b0428 | 405 | if (i + 1 + aop_map[op].op_size > x->len) |
c906108c | 406 | { |
3d263c1d | 407 | fprintf_filtered (f, _("%3d <incomplete opcode %s>\n"), |
c906108c SS |
408 | i, aop_map[op].name); |
409 | break; | |
410 | } | |
411 | ||
412 | fprintf_filtered (f, "%3d %s", i, aop_map[op].name); | |
a04b0428 | 413 | if (aop_map[op].op_size > 0) |
c906108c SS |
414 | { |
415 | fputs_filtered (" ", f); | |
c5aa993b | 416 | |
c906108c | 417 | print_longest (f, 'd', 0, |
a04b0428 | 418 | read_const (x, i + 1, aop_map[op].op_size)); |
c906108c | 419 | } |
d3ce09f5 SS |
420 | /* Handle the complicated printf arguments specially. */ |
421 | else if (op == aop_printf) | |
422 | { | |
423 | int slen, nargs; | |
424 | ||
425 | i++; | |
426 | nargs = x->buf[i++]; | |
427 | slen = x->buf[i++]; | |
428 | slen = slen * 256 + x->buf[i++]; | |
429 | fprintf_filtered (f, _(" \"%s\", %d args"), | |
430 | &(x->buf[i]), nargs); | |
431 | i += slen - 1; | |
432 | } | |
c906108c | 433 | fprintf_filtered (f, "\n"); |
a04b0428 | 434 | i += 1 + aop_map[op].op_size; |
c906108c SS |
435 | } |
436 | } | |
437 | ||
35c9c7ba SS |
438 | /* Add register REG to the register mask for expression AX. */ |
439 | void | |
440 | ax_reg_mask (struct agent_expr *ax, int reg) | |
441 | { | |
175ff332 | 442 | if (reg >= gdbarch_num_regs (ax->gdbarch)) |
35c9c7ba | 443 | { |
175ff332 HZ |
444 | /* This is a pseudo-register. */ |
445 | if (!gdbarch_ax_pseudo_register_collect_p (ax->gdbarch)) | |
446 | error (_("'%s' is a pseudo-register; " | |
447 | "GDB cannot yet trace its contents."), | |
448 | user_reg_map_regnum_to_name (ax->gdbarch, reg)); | |
449 | if (gdbarch_ax_pseudo_register_collect (ax->gdbarch, ax, reg)) | |
450 | error (_("Trace '%s' failed."), | |
451 | user_reg_map_regnum_to_name (ax->gdbarch, reg)); | |
452 | } | |
453 | else | |
454 | { | |
455 | int byte = reg / 8; | |
456 | ||
457 | /* Grow the bit mask if necessary. */ | |
458 | if (byte >= ax->reg_mask_len) | |
459 | { | |
460 | /* It's not appropriate to double here. This isn't a | |
461 | string buffer. */ | |
462 | int new_len = byte + 1; | |
463 | unsigned char *new_reg_mask = xrealloc (ax->reg_mask, | |
464 | new_len | |
465 | * sizeof (ax->reg_mask[0])); | |
466 | memset (new_reg_mask + ax->reg_mask_len, 0, | |
467 | (new_len - ax->reg_mask_len) * sizeof (ax->reg_mask[0])); | |
468 | ax->reg_mask_len = new_len; | |
469 | ax->reg_mask = new_reg_mask; | |
470 | } | |
471 | ||
472 | ax->reg_mask[byte] |= 1 << (reg % 8); | |
35c9c7ba | 473 | } |
35c9c7ba SS |
474 | } |
475 | ||
476 | /* Given an agent expression AX, fill in requirements and other descriptive | |
477 | bits. */ | |
c906108c | 478 | void |
35c9c7ba | 479 | ax_reqs (struct agent_expr *ax) |
c906108c SS |
480 | { |
481 | int i; | |
482 | int height; | |
483 | ||
3d269a59 JB |
484 | /* Jump target table. targets[i] is non-zero iff we have found a |
485 | jump to offset i. */ | |
c906108c SS |
486 | char *targets = (char *) alloca (ax->len * sizeof (targets[0])); |
487 | ||
3d269a59 JB |
488 | /* Instruction boundary table. boundary[i] is non-zero iff our scan |
489 | has reached an instruction starting at offset i. */ | |
c906108c SS |
490 | char *boundary = (char *) alloca (ax->len * sizeof (boundary[0])); |
491 | ||
3d269a59 | 492 | /* Stack height record. If either targets[i] or boundary[i] is |
c906108c SS |
493 | non-zero, heights[i] is the height the stack should have before |
494 | executing the bytecode at that point. */ | |
495 | int *heights = (int *) alloca (ax->len * sizeof (heights[0])); | |
496 | ||
497 | /* Pointer to a description of the present op. */ | |
498 | struct aop_map *op; | |
499 | ||
c906108c SS |
500 | memset (targets, 0, ax->len * sizeof (targets[0])); |
501 | memset (boundary, 0, ax->len * sizeof (boundary[0])); | |
502 | ||
35c9c7ba SS |
503 | ax->max_height = ax->min_height = height = 0; |
504 | ax->flaw = agent_flaw_none; | |
505 | ax->max_data_size = 0; | |
c906108c | 506 | |
a04b0428 | 507 | for (i = 0; i < ax->len; i += 1 + op->op_size) |
c906108c SS |
508 | { |
509 | if (ax->buf[i] > (sizeof (aop_map) / sizeof (aop_map[0]))) | |
510 | { | |
35c9c7ba | 511 | ax->flaw = agent_flaw_bad_instruction; |
c906108c SS |
512 | return; |
513 | } | |
514 | ||
515 | op = &aop_map[ax->buf[i]]; | |
516 | ||
c5aa993b | 517 | if (!op->name) |
c906108c | 518 | { |
35c9c7ba | 519 | ax->flaw = agent_flaw_bad_instruction; |
c906108c SS |
520 | return; |
521 | } | |
c5aa993b | 522 | |
a04b0428 | 523 | if (i + 1 + op->op_size > ax->len) |
c906108c | 524 | { |
35c9c7ba | 525 | ax->flaw = agent_flaw_incomplete_instruction; |
c906108c SS |
526 | return; |
527 | } | |
528 | ||
3d269a59 JB |
529 | /* If this instruction is a forward jump target, does the |
530 | current stack height match the stack height at the jump | |
531 | source? */ | |
c906108c SS |
532 | if (targets[i] && (heights[i] != height)) |
533 | { | |
35c9c7ba | 534 | ax->flaw = agent_flaw_height_mismatch; |
c906108c SS |
535 | return; |
536 | } | |
537 | ||
538 | boundary[i] = 1; | |
539 | heights[i] = height; | |
540 | ||
a04b0428 | 541 | height -= op->consumed; |
35c9c7ba SS |
542 | if (height < ax->min_height) |
543 | ax->min_height = height; | |
c906108c | 544 | height += op->produced; |
35c9c7ba SS |
545 | if (height > ax->max_height) |
546 | ax->max_height = height; | |
c906108c | 547 | |
35c9c7ba SS |
548 | if (op->data_size > ax->max_data_size) |
549 | ax->max_data_size = op->data_size; | |
c906108c SS |
550 | |
551 | /* For jump instructions, check that the target is a valid | |
c5aa993b JM |
552 | offset. If it is, record the fact that that location is a |
553 | jump target, and record the height we expect there. */ | |
c906108c SS |
554 | if (aop_goto == op - aop_map |
555 | || aop_if_goto == op - aop_map) | |
556 | { | |
557 | int target = read_const (ax, i + 1, 2); | |
558 | if (target < 0 || target >= ax->len) | |
559 | { | |
35c9c7ba | 560 | ax->flaw = agent_flaw_bad_jump; |
c906108c SS |
561 | return; |
562 | } | |
3d269a59 JB |
563 | |
564 | /* Do we have any information about what the stack height | |
565 | should be at the target? */ | |
566 | if (targets[target] || boundary[target]) | |
c906108c | 567 | { |
3d269a59 | 568 | if (heights[target] != height) |
c906108c | 569 | { |
35c9c7ba | 570 | ax->flaw = agent_flaw_height_mismatch; |
c906108c SS |
571 | return; |
572 | } | |
573 | } | |
3d269a59 JB |
574 | |
575 | /* Record the target, along with the stack height we expect. */ | |
576 | targets[target] = 1; | |
577 | heights[target] = height; | |
c906108c | 578 | } |
c5aa993b | 579 | |
c906108c SS |
580 | /* For unconditional jumps with a successor, check that the |
581 | successor is a target, and pick up its stack height. */ | |
582 | if (aop_goto == op - aop_map | |
583 | && i + 3 < ax->len) | |
584 | { | |
c5aa993b | 585 | if (!targets[i + 3]) |
c906108c | 586 | { |
35c9c7ba | 587 | ax->flaw = agent_flaw_hole; |
c906108c SS |
588 | return; |
589 | } | |
590 | ||
591 | height = heights[i + 3]; | |
592 | } | |
593 | ||
594 | /* For reg instructions, record the register in the bit mask. */ | |
595 | if (aop_reg == op - aop_map) | |
596 | { | |
597 | int reg = read_const (ax, i + 1, 2); | |
c906108c | 598 | |
35c9c7ba | 599 | ax_reg_mask (ax, reg); |
c906108c SS |
600 | } |
601 | } | |
602 | ||
603 | /* Check that all the targets are on boundaries. */ | |
604 | for (i = 0; i < ax->len; i++) | |
605 | if (targets[i] && !boundary[i]) | |
606 | { | |
35c9c7ba | 607 | ax->flaw = agent_flaw_bad_jump; |
c906108c SS |
608 | return; |
609 | } | |
610 | ||
35c9c7ba | 611 | ax->final_height = height; |
c906108c | 612 | } |