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c906108c | 1 | /* Functions for manipulating expressions designed to be executed on the agent |
32d0add0 | 2 | Copyright (C) 1998-2015 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 SS |
43 | { |
44 | struct agent_expr *x = xmalloc (sizeof (*x)); | |
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. */ | |
c5aa993b | 49 | x->buf = 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; | |
56 | x->reg_mask = xmalloc (x->reg_mask_len * sizeof (x->reg_mask[0])); | |
57 | memset (x->reg_mask, 0, x->reg_mask_len * sizeof (x->reg_mask[0])); | |
58 | ||
92bc6a20 TT |
59 | x->tracing = 0; |
60 | x->trace_string = 0; | |
61 | ||
c906108c SS |
62 | return x; |
63 | } | |
64 | ||
65 | /* Free a agent expression. */ | |
66 | void | |
fba45db2 | 67 | free_agent_expr (struct agent_expr *x) |
c906108c | 68 | { |
b8c9b27d | 69 | xfree (x->buf); |
35c9c7ba | 70 | xfree (x->reg_mask); |
b8c9b27d | 71 | xfree (x); |
c906108c SS |
72 | } |
73 | ||
f23d52e0 AC |
74 | static void |
75 | do_free_agent_expr_cleanup (void *x) | |
76 | { | |
77 | free_agent_expr (x); | |
78 | } | |
79 | ||
80 | struct cleanup * | |
81 | make_cleanup_free_agent_expr (struct agent_expr *x) | |
82 | { | |
83 | return make_cleanup (do_free_agent_expr_cleanup, x); | |
84 | } | |
85 | ||
c906108c SS |
86 | |
87 | /* Make sure that X has room for at least N more bytes. This doesn't | |
88 | affect the length, just the allocated size. */ | |
89 | static void | |
fba45db2 | 90 | grow_expr (struct agent_expr *x, int n) |
c906108c SS |
91 | { |
92 | if (x->len + n > x->size) | |
93 | { | |
94 | x->size *= 2; | |
95 | if (x->size < x->len + n) | |
96 | x->size = x->len + n + 10; | |
97 | x->buf = xrealloc (x->buf, x->size); | |
98 | } | |
99 | } | |
100 | ||
101 | ||
102 | /* Append the low N bytes of VAL as an N-byte integer to the | |
103 | expression X, in big-endian order. */ | |
104 | static void | |
fba45db2 | 105 | append_const (struct agent_expr *x, LONGEST val, int n) |
c906108c SS |
106 | { |
107 | int i; | |
108 | ||
109 | grow_expr (x, n); | |
110 | for (i = n - 1; i >= 0; i--) | |
111 | { | |
112 | x->buf[x->len + i] = val & 0xff; | |
113 | val >>= 8; | |
114 | } | |
115 | x->len += n; | |
116 | } | |
117 | ||
118 | ||
119 | /* Extract an N-byte big-endian unsigned integer from expression X at | |
120 | offset O. */ | |
121 | static LONGEST | |
fba45db2 | 122 | read_const (struct agent_expr *x, int o, int n) |
c906108c SS |
123 | { |
124 | int i; | |
125 | LONGEST accum = 0; | |
126 | ||
127 | /* Make sure we're not reading off the end of the expression. */ | |
128 | if (o + n > x->len) | |
3d263c1d | 129 | error (_("GDB bug: ax-general.c (read_const): incomplete constant")); |
c906108c SS |
130 | |
131 | for (i = 0; i < n; i++) | |
132 | accum = (accum << 8) | x->buf[o + i]; | |
c5aa993b | 133 | |
c906108c SS |
134 | return accum; |
135 | } | |
136 | ||
137 | ||
138 | /* Append a simple operator OP to EXPR. */ | |
139 | void | |
fba45db2 | 140 | ax_simple (struct agent_expr *x, enum agent_op op) |
c906108c SS |
141 | { |
142 | grow_expr (x, 1); | |
143 | x->buf[x->len++] = op; | |
144 | } | |
145 | ||
c7f96d2b TT |
146 | /* Append a pick operator to EXPR. DEPTH is the stack item to pick, |
147 | with 0 being top of stack. */ | |
2b52013f | 148 | |
c7f96d2b TT |
149 | void |
150 | ax_pick (struct agent_expr *x, int depth) | |
151 | { | |
152 | if (depth < 0 || depth > 255) | |
153 | error (_("GDB bug: ax-general.c (ax_pick): stack depth out of range")); | |
154 | ax_simple (x, aop_pick); | |
155 | append_const (x, 1, depth); | |
156 | } | |
157 | ||
c906108c SS |
158 | |
159 | /* Append a sign-extension or zero-extension instruction to EXPR, to | |
160 | extend an N-bit value. */ | |
161 | static void | |
fba45db2 | 162 | generic_ext (struct agent_expr *x, enum agent_op op, int n) |
c906108c SS |
163 | { |
164 | /* N must fit in a byte. */ | |
165 | if (n < 0 || n > 255) | |
3d263c1d | 166 | error (_("GDB bug: ax-general.c (generic_ext): bit count out of range")); |
c906108c SS |
167 | /* That had better be enough range. */ |
168 | if (sizeof (LONGEST) * 8 > 255) | |
3e43a32a MS |
169 | error (_("GDB bug: ax-general.c (generic_ext): " |
170 | "opcode has inadequate range")); | |
c906108c SS |
171 | |
172 | grow_expr (x, 2); | |
173 | x->buf[x->len++] = op; | |
174 | x->buf[x->len++] = n; | |
175 | } | |
176 | ||
177 | ||
178 | /* Append a sign-extension instruction to EXPR, to extend an N-bit value. */ | |
179 | void | |
fba45db2 | 180 | ax_ext (struct agent_expr *x, int n) |
c906108c SS |
181 | { |
182 | generic_ext (x, aop_ext, n); | |
183 | } | |
184 | ||
185 | ||
186 | /* Append a zero-extension instruction to EXPR, to extend an N-bit value. */ | |
187 | void | |
fba45db2 | 188 | ax_zero_ext (struct agent_expr *x, int n) |
c906108c SS |
189 | { |
190 | generic_ext (x, aop_zero_ext, n); | |
191 | } | |
192 | ||
193 | ||
194 | /* Append a trace_quick instruction to EXPR, to record N bytes. */ | |
195 | void | |
fba45db2 | 196 | ax_trace_quick (struct agent_expr *x, int n) |
c906108c SS |
197 | { |
198 | /* N must fit in a byte. */ | |
199 | if (n < 0 || n > 255) | |
3e43a32a MS |
200 | error (_("GDB bug: ax-general.c (ax_trace_quick): " |
201 | "size out of range for trace_quick")); | |
c906108c SS |
202 | |
203 | grow_expr (x, 2); | |
204 | x->buf[x->len++] = aop_trace_quick; | |
205 | x->buf[x->len++] = n; | |
206 | } | |
207 | ||
208 | ||
209 | /* Append a goto op to EXPR. OP is the actual op (must be aop_goto or | |
210 | aop_if_goto). We assume we don't know the target offset yet, | |
211 | because it's probably a forward branch, so we leave space in EXPR | |
212 | for the target, and return the offset in EXPR of that space, so we | |
213 | can backpatch it once we do know the target offset. Use ax_label | |
214 | to do the backpatching. */ | |
c5aa993b | 215 | int |
fba45db2 | 216 | ax_goto (struct agent_expr *x, enum agent_op op) |
c906108c SS |
217 | { |
218 | grow_expr (x, 3); | |
219 | x->buf[x->len + 0] = op; | |
220 | x->buf[x->len + 1] = 0xff; | |
221 | x->buf[x->len + 2] = 0xff; | |
222 | x->len += 3; | |
223 | return x->len - 2; | |
224 | } | |
225 | ||
226 | /* Suppose a given call to ax_goto returns some value PATCH. When you | |
227 | know the offset TARGET that goto should jump to, call | |
c5aa993b | 228 | ax_label (EXPR, PATCH, TARGET) |
c906108c SS |
229 | to patch TARGET into the ax_goto instruction. */ |
230 | void | |
fba45db2 | 231 | ax_label (struct agent_expr *x, int patch, int target) |
c906108c SS |
232 | { |
233 | /* Make sure the value is in range. Don't accept 0xffff as an | |
234 | offset; that's our magic sentinel value for unpatched branches. */ | |
235 | if (target < 0 || target >= 0xffff) | |
3d263c1d | 236 | error (_("GDB bug: ax-general.c (ax_label): label target out of range")); |
c5aa993b | 237 | |
c906108c SS |
238 | x->buf[patch] = (target >> 8) & 0xff; |
239 | x->buf[patch + 1] = target & 0xff; | |
240 | } | |
241 | ||
242 | ||
243 | /* Assemble code to push a constant on the stack. */ | |
244 | void | |
fba45db2 | 245 | ax_const_l (struct agent_expr *x, LONGEST l) |
c906108c SS |
246 | { |
247 | static enum agent_op ops[] | |
c5aa993b JM |
248 | = |
249 | {aop_const8, aop_const16, aop_const32, aop_const64}; | |
c906108c SS |
250 | int size; |
251 | int op; | |
252 | ||
253 | /* How big is the number? 'op' keeps track of which opcode to use. | |
254 | Notice that we don't really care whether the original number was | |
255 | signed or unsigned; we always reproduce the value exactly, and | |
256 | use the shortest representation. */ | |
257 | for (op = 0, size = 8; size < 64; size *= 2, op++) | |
44a81774 | 258 | { |
cf3e25ca | 259 | LONGEST lim = ((LONGEST) 1) << (size - 1); |
44a81774 JB |
260 | |
261 | if (-lim <= l && l <= lim - 1) | |
262 | break; | |
263 | } | |
c906108c | 264 | |
0e2de366 | 265 | /* Emit the right opcode... */ |
c906108c SS |
266 | ax_simple (x, ops[op]); |
267 | ||
268 | /* Emit the low SIZE bytes as an unsigned number. We know that | |
269 | sign-extending this will yield l. */ | |
270 | append_const (x, l, size / 8); | |
271 | ||
272 | /* Now, if it was negative, and not full-sized, sign-extend it. */ | |
273 | if (l < 0 && size < 64) | |
274 | ax_ext (x, size); | |
275 | } | |
276 | ||
277 | ||
278 | void | |
fba45db2 | 279 | ax_const_d (struct agent_expr *x, LONGEST d) |
c906108c SS |
280 | { |
281 | /* FIXME: floating-point support not present yet. */ | |
3e43a32a MS |
282 | error (_("GDB bug: ax-general.c (ax_const_d): " |
283 | "floating point not supported yet")); | |
c906108c SS |
284 | } |
285 | ||
286 | ||
287 | /* Assemble code to push the value of register number REG on the | |
288 | stack. */ | |
c5aa993b | 289 | void |
fba45db2 | 290 | ax_reg (struct agent_expr *x, int reg) |
c906108c | 291 | { |
175ff332 HZ |
292 | if (reg >= gdbarch_num_regs (x->gdbarch)) |
293 | { | |
294 | /* This is a pseudo-register. */ | |
295 | if (!gdbarch_ax_pseudo_register_push_stack_p (x->gdbarch)) | |
296 | error (_("'%s' is a pseudo-register; " | |
297 | "GDB cannot yet trace its contents."), | |
298 | user_reg_map_regnum_to_name (x->gdbarch, reg)); | |
299 | if (gdbarch_ax_pseudo_register_push_stack (x->gdbarch, x, reg)) | |
300 | error (_("Trace '%s' failed."), | |
301 | user_reg_map_regnum_to_name (x->gdbarch, reg)); | |
302 | } | |
303 | else | |
304 | { | |
305 | /* Make sure the register number is in range. */ | |
306 | if (reg < 0 || reg > 0xffff) | |
3e43a32a MS |
307 | error (_("GDB bug: ax-general.c (ax_reg): " |
308 | "register number out of range")); | |
175ff332 HZ |
309 | grow_expr (x, 3); |
310 | x->buf[x->len] = aop_reg; | |
311 | x->buf[x->len + 1] = (reg >> 8) & 0xff; | |
312 | x->buf[x->len + 2] = (reg) & 0xff; | |
313 | x->len += 3; | |
314 | } | |
c906108c | 315 | } |
f61e138d SS |
316 | |
317 | /* Assemble code to operate on a trace state variable. */ | |
318 | ||
319 | void | |
320 | ax_tsv (struct agent_expr *x, enum agent_op op, int num) | |
321 | { | |
322 | /* Make sure the tsv number is in range. */ | |
323 | if (num < 0 || num > 0xffff) | |
3e43a32a MS |
324 | internal_error (__FILE__, __LINE__, |
325 | _("ax-general.c (ax_tsv): variable " | |
326 | "number is %d, out of range"), num); | |
f61e138d SS |
327 | |
328 | grow_expr (x, 3); | |
329 | x->buf[x->len] = op; | |
330 | x->buf[x->len + 1] = (num >> 8) & 0xff; | |
331 | x->buf[x->len + 2] = (num) & 0xff; | |
332 | x->len += 3; | |
333 | } | |
d3ce09f5 SS |
334 | |
335 | /* Append a string to the expression. Note that the string is going | |
336 | into the bytecodes directly, not on the stack. As a precaution, | |
337 | include both length as prefix, and terminate with a NUL. (The NUL | |
338 | is counted in the length.) */ | |
339 | ||
340 | void | |
741d92cf | 341 | ax_string (struct agent_expr *x, const char *str, int slen) |
d3ce09f5 SS |
342 | { |
343 | int i; | |
344 | ||
345 | /* Make sure the string length is reasonable. */ | |
346 | if (slen < 0 || slen > 0xffff) | |
347 | internal_error (__FILE__, __LINE__, | |
348 | _("ax-general.c (ax_string): string " | |
349 | "length is %d, out of allowed range"), slen); | |
350 | ||
351 | grow_expr (x, 2 + slen + 1); | |
352 | x->buf[x->len++] = ((slen + 1) >> 8) & 0xff; | |
353 | x->buf[x->len++] = (slen + 1) & 0xff; | |
354 | for (i = 0; i < slen; ++i) | |
355 | x->buf[x->len++] = str[i]; | |
356 | x->buf[x->len++] = '\0'; | |
357 | } | |
c5aa993b | 358 | \f |
c906108c SS |
359 | |
360 | ||
c906108c SS |
361 | /* Functions for disassembling agent expressions, and otherwise |
362 | debugging the expression compiler. */ | |
363 | ||
c5aa993b JM |
364 | struct aop_map aop_map[] = |
365 | { | |
94d5e490 TT |
366 | {0, 0, 0, 0, 0} |
367 | #define DEFOP(NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED, VALUE) \ | |
368 | , { # NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED } | |
369 | #include "ax.def" | |
370 | #undef DEFOP | |
c906108c SS |
371 | }; |
372 | ||
373 | ||
374 | /* Disassemble the expression EXPR, writing to F. */ | |
375 | void | |
fba45db2 | 376 | ax_print (struct ui_file *f, struct agent_expr *x) |
c906108c SS |
377 | { |
378 | int i; | |
c906108c | 379 | |
35c9c7ba SS |
380 | fprintf_filtered (f, _("Scope: %s\n"), paddress (x->gdbarch, x->scope)); |
381 | fprintf_filtered (f, _("Reg mask:")); | |
382 | for (i = 0; i < x->reg_mask_len; ++i) | |
383 | fprintf_filtered (f, _(" %02x"), x->reg_mask[i]); | |
384 | fprintf_filtered (f, _("\n")); | |
385 | ||
c906108c SS |
386 | /* Check the size of the name array against the number of entries in |
387 | the enum, to catch additions that people didn't sync. */ | |
388 | if ((sizeof (aop_map) / sizeof (aop_map[0])) | |
389 | != aop_last) | |
3d263c1d | 390 | error (_("GDB bug: ax-general.c (ax_print): opcode map out of sync")); |
c5aa993b JM |
391 | |
392 | for (i = 0; i < x->len;) | |
c906108c SS |
393 | { |
394 | enum agent_op op = x->buf[i]; | |
395 | ||
396 | if (op >= (sizeof (aop_map) / sizeof (aop_map[0])) | |
c5aa993b | 397 | || !aop_map[op].name) |
c906108c | 398 | { |
3d263c1d | 399 | fprintf_filtered (f, _("%3d <bad opcode %02x>\n"), i, op); |
c906108c SS |
400 | i++; |
401 | continue; | |
402 | } | |
a04b0428 | 403 | if (i + 1 + aop_map[op].op_size > x->len) |
c906108c | 404 | { |
3d263c1d | 405 | fprintf_filtered (f, _("%3d <incomplete opcode %s>\n"), |
c906108c SS |
406 | i, aop_map[op].name); |
407 | break; | |
408 | } | |
409 | ||
410 | fprintf_filtered (f, "%3d %s", i, aop_map[op].name); | |
a04b0428 | 411 | if (aop_map[op].op_size > 0) |
c906108c SS |
412 | { |
413 | fputs_filtered (" ", f); | |
c5aa993b | 414 | |
c906108c | 415 | print_longest (f, 'd', 0, |
a04b0428 | 416 | read_const (x, i + 1, aop_map[op].op_size)); |
c906108c | 417 | } |
d3ce09f5 SS |
418 | /* Handle the complicated printf arguments specially. */ |
419 | else if (op == aop_printf) | |
420 | { | |
421 | int slen, nargs; | |
422 | ||
423 | i++; | |
424 | nargs = x->buf[i++]; | |
425 | slen = x->buf[i++]; | |
426 | slen = slen * 256 + x->buf[i++]; | |
427 | fprintf_filtered (f, _(" \"%s\", %d args"), | |
428 | &(x->buf[i]), nargs); | |
429 | i += slen - 1; | |
430 | } | |
c906108c | 431 | fprintf_filtered (f, "\n"); |
a04b0428 | 432 | i += 1 + aop_map[op].op_size; |
c906108c SS |
433 | } |
434 | } | |
435 | ||
35c9c7ba SS |
436 | /* Add register REG to the register mask for expression AX. */ |
437 | void | |
438 | ax_reg_mask (struct agent_expr *ax, int reg) | |
439 | { | |
175ff332 | 440 | if (reg >= gdbarch_num_regs (ax->gdbarch)) |
35c9c7ba | 441 | { |
175ff332 HZ |
442 | /* This is a pseudo-register. */ |
443 | if (!gdbarch_ax_pseudo_register_collect_p (ax->gdbarch)) | |
444 | error (_("'%s' is a pseudo-register; " | |
445 | "GDB cannot yet trace its contents."), | |
446 | user_reg_map_regnum_to_name (ax->gdbarch, reg)); | |
447 | if (gdbarch_ax_pseudo_register_collect (ax->gdbarch, ax, reg)) | |
448 | error (_("Trace '%s' failed."), | |
449 | user_reg_map_regnum_to_name (ax->gdbarch, reg)); | |
450 | } | |
451 | else | |
452 | { | |
453 | int byte = reg / 8; | |
454 | ||
455 | /* Grow the bit mask if necessary. */ | |
456 | if (byte >= ax->reg_mask_len) | |
457 | { | |
458 | /* It's not appropriate to double here. This isn't a | |
459 | string buffer. */ | |
460 | int new_len = byte + 1; | |
461 | unsigned char *new_reg_mask = xrealloc (ax->reg_mask, | |
462 | new_len | |
463 | * sizeof (ax->reg_mask[0])); | |
464 | memset (new_reg_mask + ax->reg_mask_len, 0, | |
465 | (new_len - ax->reg_mask_len) * sizeof (ax->reg_mask[0])); | |
466 | ax->reg_mask_len = new_len; | |
467 | ax->reg_mask = new_reg_mask; | |
468 | } | |
469 | ||
470 | ax->reg_mask[byte] |= 1 << (reg % 8); | |
35c9c7ba | 471 | } |
35c9c7ba SS |
472 | } |
473 | ||
474 | /* Given an agent expression AX, fill in requirements and other descriptive | |
475 | bits. */ | |
c906108c | 476 | void |
35c9c7ba | 477 | ax_reqs (struct agent_expr *ax) |
c906108c SS |
478 | { |
479 | int i; | |
480 | int height; | |
481 | ||
3d269a59 JB |
482 | /* Jump target table. targets[i] is non-zero iff we have found a |
483 | jump to offset i. */ | |
c906108c SS |
484 | char *targets = (char *) alloca (ax->len * sizeof (targets[0])); |
485 | ||
3d269a59 JB |
486 | /* Instruction boundary table. boundary[i] is non-zero iff our scan |
487 | has reached an instruction starting at offset i. */ | |
c906108c SS |
488 | char *boundary = (char *) alloca (ax->len * sizeof (boundary[0])); |
489 | ||
3d269a59 | 490 | /* Stack height record. If either targets[i] or boundary[i] is |
c906108c SS |
491 | non-zero, heights[i] is the height the stack should have before |
492 | executing the bytecode at that point. */ | |
493 | int *heights = (int *) alloca (ax->len * sizeof (heights[0])); | |
494 | ||
495 | /* Pointer to a description of the present op. */ | |
496 | struct aop_map *op; | |
497 | ||
c906108c SS |
498 | memset (targets, 0, ax->len * sizeof (targets[0])); |
499 | memset (boundary, 0, ax->len * sizeof (boundary[0])); | |
500 | ||
35c9c7ba SS |
501 | ax->max_height = ax->min_height = height = 0; |
502 | ax->flaw = agent_flaw_none; | |
503 | ax->max_data_size = 0; | |
c906108c | 504 | |
a04b0428 | 505 | for (i = 0; i < ax->len; i += 1 + op->op_size) |
c906108c SS |
506 | { |
507 | if (ax->buf[i] > (sizeof (aop_map) / sizeof (aop_map[0]))) | |
508 | { | |
35c9c7ba | 509 | ax->flaw = agent_flaw_bad_instruction; |
c906108c SS |
510 | return; |
511 | } | |
512 | ||
513 | op = &aop_map[ax->buf[i]]; | |
514 | ||
c5aa993b | 515 | if (!op->name) |
c906108c | 516 | { |
35c9c7ba | 517 | ax->flaw = agent_flaw_bad_instruction; |
c906108c SS |
518 | return; |
519 | } | |
c5aa993b | 520 | |
a04b0428 | 521 | if (i + 1 + op->op_size > ax->len) |
c906108c | 522 | { |
35c9c7ba | 523 | ax->flaw = agent_flaw_incomplete_instruction; |
c906108c SS |
524 | return; |
525 | } | |
526 | ||
3d269a59 JB |
527 | /* If this instruction is a forward jump target, does the |
528 | current stack height match the stack height at the jump | |
529 | source? */ | |
c906108c SS |
530 | if (targets[i] && (heights[i] != height)) |
531 | { | |
35c9c7ba | 532 | ax->flaw = agent_flaw_height_mismatch; |
c906108c SS |
533 | return; |
534 | } | |
535 | ||
536 | boundary[i] = 1; | |
537 | heights[i] = height; | |
538 | ||
a04b0428 | 539 | height -= op->consumed; |
35c9c7ba SS |
540 | if (height < ax->min_height) |
541 | ax->min_height = height; | |
c906108c | 542 | height += op->produced; |
35c9c7ba SS |
543 | if (height > ax->max_height) |
544 | ax->max_height = height; | |
c906108c | 545 | |
35c9c7ba SS |
546 | if (op->data_size > ax->max_data_size) |
547 | ax->max_data_size = op->data_size; | |
c906108c SS |
548 | |
549 | /* For jump instructions, check that the target is a valid | |
c5aa993b JM |
550 | offset. If it is, record the fact that that location is a |
551 | jump target, and record the height we expect there. */ | |
c906108c SS |
552 | if (aop_goto == op - aop_map |
553 | || aop_if_goto == op - aop_map) | |
554 | { | |
555 | int target = read_const (ax, i + 1, 2); | |
556 | if (target < 0 || target >= ax->len) | |
557 | { | |
35c9c7ba | 558 | ax->flaw = agent_flaw_bad_jump; |
c906108c SS |
559 | return; |
560 | } | |
3d269a59 JB |
561 | |
562 | /* Do we have any information about what the stack height | |
563 | should be at the target? */ | |
564 | if (targets[target] || boundary[target]) | |
c906108c | 565 | { |
3d269a59 | 566 | if (heights[target] != height) |
c906108c | 567 | { |
35c9c7ba | 568 | ax->flaw = agent_flaw_height_mismatch; |
c906108c SS |
569 | return; |
570 | } | |
571 | } | |
3d269a59 JB |
572 | |
573 | /* Record the target, along with the stack height we expect. */ | |
574 | targets[target] = 1; | |
575 | heights[target] = height; | |
c906108c | 576 | } |
c5aa993b | 577 | |
c906108c SS |
578 | /* For unconditional jumps with a successor, check that the |
579 | successor is a target, and pick up its stack height. */ | |
580 | if (aop_goto == op - aop_map | |
581 | && i + 3 < ax->len) | |
582 | { | |
c5aa993b | 583 | if (!targets[i + 3]) |
c906108c | 584 | { |
35c9c7ba | 585 | ax->flaw = agent_flaw_hole; |
c906108c SS |
586 | return; |
587 | } | |
588 | ||
589 | height = heights[i + 3]; | |
590 | } | |
591 | ||
592 | /* For reg instructions, record the register in the bit mask. */ | |
593 | if (aop_reg == op - aop_map) | |
594 | { | |
595 | int reg = read_const (ax, i + 1, 2); | |
c906108c | 596 | |
35c9c7ba | 597 | ax_reg_mask (ax, reg); |
c906108c SS |
598 | } |
599 | } | |
600 | ||
601 | /* Check that all the targets are on boundaries. */ | |
602 | for (i = 0; i < ax->len; i++) | |
603 | if (targets[i] && !boundary[i]) | |
604 | { | |
35c9c7ba | 605 | ax->flaw = agent_flaw_bad_jump; |
c906108c SS |
606 | return; |
607 | } | |
608 | ||
35c9c7ba | 609 | ax->final_height = height; |
c906108c | 610 | } |