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55aa24fb SDJ |
1 | /* SystemTap probe support for GDB. |
2 | ||
28e7fd62 | 3 | Copyright (C) 2012-2013 Free Software Foundation, Inc. |
55aa24fb SDJ |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #include "defs.h" | |
21 | #include "stap-probe.h" | |
22 | #include "probe.h" | |
23 | #include "vec.h" | |
24 | #include "ui-out.h" | |
25 | #include "objfiles.h" | |
26 | #include "arch-utils.h" | |
27 | #include "command.h" | |
28 | #include "gdbcmd.h" | |
29 | #include "filenames.h" | |
30 | #include "value.h" | |
31 | #include "exceptions.h" | |
32 | #include "ax.h" | |
33 | #include "ax-gdb.h" | |
34 | #include "complaints.h" | |
35 | #include "cli/cli-utils.h" | |
36 | #include "linespec.h" | |
37 | #include "user-regs.h" | |
38 | #include "parser-defs.h" | |
39 | #include "language.h" | |
40 | #include "elf-bfd.h" | |
41 | ||
42 | #include <ctype.h> | |
43 | ||
44 | /* The name of the SystemTap section where we will find information about | |
45 | the probes. */ | |
46 | ||
47 | #define STAP_BASE_SECTION_NAME ".stapsdt.base" | |
48 | ||
49 | /* Forward declaration. */ | |
50 | ||
51 | static const struct probe_ops stap_probe_ops; | |
52 | ||
53 | /* Should we display debug information for the probe's argument expression | |
54 | parsing? */ | |
55 | ||
ccce17b0 | 56 | static unsigned int stap_expression_debug = 0; |
55aa24fb SDJ |
57 | |
58 | /* The various possibilities of bitness defined for a probe's argument. | |
59 | ||
60 | The relationship is: | |
61 | ||
62 | - STAP_ARG_BITNESS_UNDEFINED: The user hasn't specified the bitness. | |
63 | - STAP_ARG_BITNESS_32BIT_UNSIGNED: argument string starts with `4@'. | |
64 | - STAP_ARG_BITNESS_32BIT_SIGNED: argument string starts with `-4@'. | |
65 | - STAP_ARG_BITNESS_64BIT_UNSIGNED: argument string starts with `8@'. | |
66 | - STAP_ARG_BITNESS_64BIT_SIGNED: argument string starts with `-8@'. */ | |
67 | ||
68 | enum stap_arg_bitness | |
69 | { | |
70 | STAP_ARG_BITNESS_UNDEFINED, | |
71 | STAP_ARG_BITNESS_32BIT_UNSIGNED, | |
72 | STAP_ARG_BITNESS_32BIT_SIGNED, | |
73 | STAP_ARG_BITNESS_64BIT_UNSIGNED, | |
74 | STAP_ARG_BITNESS_64BIT_SIGNED, | |
75 | }; | |
76 | ||
77 | /* The following structure represents a single argument for the probe. */ | |
78 | ||
79 | struct stap_probe_arg | |
80 | { | |
81 | /* The bitness of this argument. */ | |
82 | enum stap_arg_bitness bitness; | |
83 | ||
84 | /* The corresponding `struct type *' to the bitness. */ | |
85 | struct type *atype; | |
86 | ||
87 | /* The argument converted to an internal GDB expression. */ | |
88 | struct expression *aexpr; | |
89 | }; | |
90 | ||
91 | typedef struct stap_probe_arg stap_probe_arg_s; | |
92 | DEF_VEC_O (stap_probe_arg_s); | |
93 | ||
94 | struct stap_probe | |
95 | { | |
96 | /* Generic information about the probe. This shall be the first element | |
97 | of this struct, in order to maintain binary compatibility with the | |
98 | `struct probe' and be able to fully abstract it. */ | |
99 | struct probe p; | |
100 | ||
101 | /* If the probe has a semaphore associated, then this is the value of | |
102 | it. */ | |
103 | CORE_ADDR sem_addr; | |
104 | ||
105 | unsigned int args_parsed : 1; | |
106 | union | |
107 | { | |
108 | const char *text; | |
109 | ||
110 | /* Information about each argument. This is an array of `stap_probe_arg', | |
111 | with each entry representing one argument. */ | |
112 | VEC (stap_probe_arg_s) *vec; | |
113 | } | |
114 | args_u; | |
115 | }; | |
116 | ||
117 | /* When parsing the arguments, we have to establish different precedences | |
118 | for the various kinds of asm operators. This enumeration represents those | |
119 | precedences. | |
120 | ||
121 | This logic behind this is available at | |
122 | <http://sourceware.org/binutils/docs/as/Infix-Ops.html#Infix-Ops>, or using | |
123 | the command "info '(as)Infix Ops'". */ | |
124 | ||
125 | enum stap_operand_prec | |
126 | { | |
127 | /* Lowest precedence, used for non-recognized operands or for the beginning | |
128 | of the parsing process. */ | |
129 | STAP_OPERAND_PREC_NONE = 0, | |
130 | ||
131 | /* Precedence of logical OR. */ | |
132 | STAP_OPERAND_PREC_LOGICAL_OR, | |
133 | ||
134 | /* Precedence of logical AND. */ | |
135 | STAP_OPERAND_PREC_LOGICAL_AND, | |
136 | ||
137 | /* Precedence of additive (plus, minus) and comparative (equal, less, | |
138 | greater-than, etc) operands. */ | |
139 | STAP_OPERAND_PREC_ADD_CMP, | |
140 | ||
141 | /* Precedence of bitwise operands (bitwise OR, XOR, bitwise AND, | |
142 | logical NOT). */ | |
143 | STAP_OPERAND_PREC_BITWISE, | |
144 | ||
145 | /* Precedence of multiplicative operands (multiplication, division, | |
146 | remainder, left shift and right shift). */ | |
147 | STAP_OPERAND_PREC_MUL | |
148 | }; | |
149 | ||
150 | static void stap_parse_argument_1 (struct stap_parse_info *p, int has_lhs, | |
151 | enum stap_operand_prec prec); | |
152 | ||
153 | static void stap_parse_argument_conditionally (struct stap_parse_info *p); | |
154 | ||
155 | /* Returns 1 if *S is an operator, zero otherwise. */ | |
156 | ||
fcf57f19 | 157 | static int stap_is_operator (const char *op); |
55aa24fb SDJ |
158 | |
159 | static void | |
160 | show_stapexpressiondebug (struct ui_file *file, int from_tty, | |
161 | struct cmd_list_element *c, const char *value) | |
162 | { | |
163 | fprintf_filtered (file, _("SystemTap Probe expression debugging is %s.\n"), | |
164 | value); | |
165 | } | |
166 | ||
167 | /* Returns the operator precedence level of OP, or STAP_OPERAND_PREC_NONE | |
168 | if the operator code was not recognized. */ | |
169 | ||
170 | static enum stap_operand_prec | |
171 | stap_get_operator_prec (enum exp_opcode op) | |
172 | { | |
173 | switch (op) | |
174 | { | |
175 | case BINOP_LOGICAL_OR: | |
176 | return STAP_OPERAND_PREC_LOGICAL_OR; | |
177 | ||
178 | case BINOP_LOGICAL_AND: | |
179 | return STAP_OPERAND_PREC_LOGICAL_AND; | |
180 | ||
181 | case BINOP_ADD: | |
182 | case BINOP_SUB: | |
183 | case BINOP_EQUAL: | |
184 | case BINOP_NOTEQUAL: | |
185 | case BINOP_LESS: | |
186 | case BINOP_LEQ: | |
187 | case BINOP_GTR: | |
188 | case BINOP_GEQ: | |
189 | return STAP_OPERAND_PREC_ADD_CMP; | |
190 | ||
191 | case BINOP_BITWISE_IOR: | |
192 | case BINOP_BITWISE_AND: | |
193 | case BINOP_BITWISE_XOR: | |
194 | case UNOP_LOGICAL_NOT: | |
195 | return STAP_OPERAND_PREC_BITWISE; | |
196 | ||
197 | case BINOP_MUL: | |
198 | case BINOP_DIV: | |
199 | case BINOP_REM: | |
200 | case BINOP_LSH: | |
201 | case BINOP_RSH: | |
202 | return STAP_OPERAND_PREC_MUL; | |
203 | ||
204 | default: | |
205 | return STAP_OPERAND_PREC_NONE; | |
206 | } | |
207 | } | |
208 | ||
209 | /* Given S, read the operator in it and fills the OP pointer with its code. | |
210 | Return 1 on success, zero if the operator was not recognized. */ | |
211 | ||
fcf57f19 SDJ |
212 | static enum exp_opcode |
213 | stap_get_opcode (const char **s) | |
55aa24fb SDJ |
214 | { |
215 | const char c = **s; | |
fcf57f19 | 216 | enum exp_opcode op; |
55aa24fb SDJ |
217 | |
218 | *s += 1; | |
219 | ||
220 | switch (c) | |
221 | { | |
222 | case '*': | |
fcf57f19 | 223 | op = BINOP_MUL; |
55aa24fb SDJ |
224 | break; |
225 | ||
226 | case '/': | |
fcf57f19 | 227 | op = BINOP_DIV; |
55aa24fb SDJ |
228 | break; |
229 | ||
230 | case '%': | |
fcf57f19 | 231 | op = BINOP_REM; |
55aa24fb SDJ |
232 | break; |
233 | ||
234 | case '<': | |
fcf57f19 | 235 | op = BINOP_LESS; |
55aa24fb SDJ |
236 | if (**s == '<') |
237 | { | |
238 | *s += 1; | |
fcf57f19 | 239 | op = BINOP_LSH; |
55aa24fb SDJ |
240 | } |
241 | else if (**s == '=') | |
242 | { | |
243 | *s += 1; | |
fcf57f19 | 244 | op = BINOP_LEQ; |
55aa24fb SDJ |
245 | } |
246 | else if (**s == '>') | |
247 | { | |
248 | *s += 1; | |
fcf57f19 | 249 | op = BINOP_NOTEQUAL; |
55aa24fb SDJ |
250 | } |
251 | break; | |
252 | ||
253 | case '>': | |
fcf57f19 | 254 | op = BINOP_GTR; |
55aa24fb SDJ |
255 | if (**s == '>') |
256 | { | |
257 | *s += 1; | |
fcf57f19 | 258 | op = BINOP_RSH; |
55aa24fb SDJ |
259 | } |
260 | else if (**s == '=') | |
261 | { | |
262 | *s += 1; | |
fcf57f19 | 263 | op = BINOP_GEQ; |
55aa24fb SDJ |
264 | } |
265 | break; | |
266 | ||
267 | case '|': | |
fcf57f19 | 268 | op = BINOP_BITWISE_IOR; |
55aa24fb SDJ |
269 | if (**s == '|') |
270 | { | |
271 | *s += 1; | |
fcf57f19 | 272 | op = BINOP_LOGICAL_OR; |
55aa24fb SDJ |
273 | } |
274 | break; | |
275 | ||
276 | case '&': | |
fcf57f19 | 277 | op = BINOP_BITWISE_AND; |
55aa24fb SDJ |
278 | if (**s == '&') |
279 | { | |
280 | *s += 1; | |
fcf57f19 | 281 | op = BINOP_LOGICAL_AND; |
55aa24fb SDJ |
282 | } |
283 | break; | |
284 | ||
285 | case '^': | |
fcf57f19 | 286 | op = BINOP_BITWISE_XOR; |
55aa24fb SDJ |
287 | break; |
288 | ||
289 | case '!': | |
fcf57f19 | 290 | op = UNOP_LOGICAL_NOT; |
55aa24fb SDJ |
291 | break; |
292 | ||
293 | case '+': | |
fcf57f19 | 294 | op = BINOP_ADD; |
55aa24fb SDJ |
295 | break; |
296 | ||
297 | case '-': | |
fcf57f19 | 298 | op = BINOP_SUB; |
55aa24fb SDJ |
299 | break; |
300 | ||
301 | case '=': | |
fcf57f19 SDJ |
302 | gdb_assert (**s == '='); |
303 | op = BINOP_EQUAL; | |
55aa24fb SDJ |
304 | break; |
305 | ||
306 | default: | |
fcf57f19 SDJ |
307 | internal_error (__FILE__, __LINE__, |
308 | _("Invalid opcode in expression `%s' for SystemTap" | |
309 | "probe"), *s); | |
55aa24fb SDJ |
310 | } |
311 | ||
fcf57f19 | 312 | return op; |
55aa24fb SDJ |
313 | } |
314 | ||
315 | /* Given the bitness of the argument, represented by B, return the | |
316 | corresponding `struct type *'. */ | |
317 | ||
318 | static struct type * | |
319 | stap_get_expected_argument_type (struct gdbarch *gdbarch, | |
320 | enum stap_arg_bitness b) | |
321 | { | |
322 | switch (b) | |
323 | { | |
324 | case STAP_ARG_BITNESS_UNDEFINED: | |
325 | if (gdbarch_addr_bit (gdbarch) == 32) | |
326 | return builtin_type (gdbarch)->builtin_uint32; | |
327 | else | |
328 | return builtin_type (gdbarch)->builtin_uint64; | |
329 | ||
330 | case STAP_ARG_BITNESS_32BIT_SIGNED: | |
331 | return builtin_type (gdbarch)->builtin_int32; | |
332 | ||
333 | case STAP_ARG_BITNESS_32BIT_UNSIGNED: | |
334 | return builtin_type (gdbarch)->builtin_uint32; | |
335 | ||
336 | case STAP_ARG_BITNESS_64BIT_SIGNED: | |
337 | return builtin_type (gdbarch)->builtin_int64; | |
338 | ||
339 | case STAP_ARG_BITNESS_64BIT_UNSIGNED: | |
340 | return builtin_type (gdbarch)->builtin_uint64; | |
341 | ||
342 | default: | |
343 | internal_error (__FILE__, __LINE__, | |
344 | _("Undefined bitness for probe.")); | |
345 | break; | |
346 | } | |
347 | } | |
348 | ||
349 | /* Function responsible for parsing a register operand according to | |
350 | SystemTap parlance. Assuming: | |
351 | ||
352 | RP = register prefix | |
353 | RS = register suffix | |
354 | RIP = register indirection prefix | |
355 | RIS = register indirection suffix | |
356 | ||
357 | Then a register operand can be: | |
358 | ||
359 | [RIP] [RP] REGISTER [RS] [RIS] | |
360 | ||
361 | This function takes care of a register's indirection, displacement and | |
362 | direct access. It also takes into consideration the fact that some | |
363 | registers are named differently inside and outside GDB, e.g., PPC's | |
364 | general-purpose registers are represented by integers in the assembly | |
365 | language (e.g., `15' is the 15th general-purpose register), but inside | |
366 | GDB they have a prefix (the letter `r') appended. */ | |
367 | ||
368 | static void | |
369 | stap_parse_register_operand (struct stap_parse_info *p) | |
370 | { | |
371 | /* Simple flag to indicate whether we have seen a minus signal before | |
372 | certain number. */ | |
373 | int got_minus = 0; | |
374 | ||
375 | /* Flags to indicate whether this register access is being displaced and/or | |
376 | indirected. */ | |
377 | int disp_p = 0, indirect_p = 0; | |
378 | struct gdbarch *gdbarch = p->gdbarch; | |
379 | ||
380 | /* Needed to generate the register name as a part of an expression. */ | |
381 | struct stoken str; | |
382 | ||
383 | /* Variables used to extract the register name from the probe's | |
384 | argument. */ | |
385 | const char *start; | |
386 | char *regname; | |
387 | int len; | |
388 | ||
389 | /* Prefixes for the parser. */ | |
390 | const char *reg_prefix = gdbarch_stap_register_prefix (gdbarch); | |
391 | const char *reg_ind_prefix | |
392 | = gdbarch_stap_register_indirection_prefix (gdbarch); | |
393 | const char *gdb_reg_prefix = gdbarch_stap_gdb_register_prefix (gdbarch); | |
394 | int reg_prefix_len = reg_prefix ? strlen (reg_prefix) : 0; | |
395 | int reg_ind_prefix_len = reg_ind_prefix ? strlen (reg_ind_prefix) : 0; | |
396 | int gdb_reg_prefix_len = gdb_reg_prefix ? strlen (gdb_reg_prefix) : 0; | |
397 | ||
398 | /* Suffixes for the parser. */ | |
399 | const char *reg_suffix = gdbarch_stap_register_suffix (gdbarch); | |
400 | const char *reg_ind_suffix | |
401 | = gdbarch_stap_register_indirection_suffix (gdbarch); | |
402 | const char *gdb_reg_suffix = gdbarch_stap_gdb_register_suffix (gdbarch); | |
403 | int reg_suffix_len = reg_suffix ? strlen (reg_suffix) : 0; | |
404 | int reg_ind_suffix_len = reg_ind_suffix ? strlen (reg_ind_suffix) : 0; | |
405 | int gdb_reg_suffix_len = gdb_reg_suffix ? strlen (gdb_reg_suffix) : 0; | |
406 | ||
407 | /* Checking for a displacement argument. */ | |
408 | if (*p->arg == '+') | |
409 | { | |
410 | /* If it's a plus sign, we don't need to do anything, just advance the | |
411 | pointer. */ | |
412 | ++p->arg; | |
413 | } | |
414 | ||
415 | if (*p->arg == '-') | |
416 | { | |
417 | got_minus = 1; | |
418 | ++p->arg; | |
419 | } | |
420 | ||
421 | if (isdigit (*p->arg)) | |
422 | { | |
423 | /* The value of the displacement. */ | |
424 | long displacement; | |
a0bcdaa7 | 425 | char *endp; |
55aa24fb SDJ |
426 | |
427 | disp_p = 1; | |
a0bcdaa7 PA |
428 | displacement = strtol (p->arg, &endp, 10); |
429 | p->arg = endp; | |
55aa24fb SDJ |
430 | |
431 | /* Generating the expression for the displacement. */ | |
432 | write_exp_elt_opcode (OP_LONG); | |
433 | write_exp_elt_type (builtin_type (gdbarch)->builtin_long); | |
434 | write_exp_elt_longcst (displacement); | |
435 | write_exp_elt_opcode (OP_LONG); | |
436 | if (got_minus) | |
437 | write_exp_elt_opcode (UNOP_NEG); | |
438 | } | |
439 | ||
440 | /* Getting rid of register indirection prefix. */ | |
441 | if (reg_ind_prefix | |
442 | && strncmp (p->arg, reg_ind_prefix, reg_ind_prefix_len) == 0) | |
443 | { | |
444 | indirect_p = 1; | |
445 | p->arg += reg_ind_prefix_len; | |
446 | } | |
447 | ||
448 | if (disp_p && !indirect_p) | |
449 | error (_("Invalid register displacement syntax on expression `%s'."), | |
450 | p->saved_arg); | |
451 | ||
452 | /* Getting rid of register prefix. */ | |
453 | if (reg_prefix && strncmp (p->arg, reg_prefix, reg_prefix_len) == 0) | |
454 | p->arg += reg_prefix_len; | |
455 | ||
456 | /* Now we should have only the register name. Let's extract it and get | |
457 | the associated number. */ | |
458 | start = p->arg; | |
459 | ||
460 | /* We assume the register name is composed by letters and numbers. */ | |
461 | while (isalnum (*p->arg)) | |
462 | ++p->arg; | |
463 | ||
464 | len = p->arg - start; | |
465 | ||
466 | regname = alloca (len + gdb_reg_prefix_len + gdb_reg_suffix_len + 1); | |
467 | regname[0] = '\0'; | |
468 | ||
469 | /* We only add the GDB's register prefix/suffix if we are dealing with | |
470 | a numeric register. */ | |
471 | if (gdb_reg_prefix && isdigit (*start)) | |
472 | { | |
473 | strncpy (regname, gdb_reg_prefix, gdb_reg_prefix_len); | |
474 | strncpy (regname + gdb_reg_prefix_len, start, len); | |
475 | ||
476 | if (gdb_reg_suffix) | |
477 | strncpy (regname + gdb_reg_prefix_len + len, | |
478 | gdb_reg_suffix, gdb_reg_suffix_len); | |
479 | ||
480 | len += gdb_reg_prefix_len + gdb_reg_suffix_len; | |
481 | } | |
482 | else | |
483 | strncpy (regname, start, len); | |
484 | ||
485 | regname[len] = '\0'; | |
486 | ||
487 | /* Is this a valid register name? */ | |
488 | if (user_reg_map_name_to_regnum (gdbarch, regname, len) == -1) | |
489 | error (_("Invalid register name `%s' on expression `%s'."), | |
490 | regname, p->saved_arg); | |
491 | ||
492 | write_exp_elt_opcode (OP_REGISTER); | |
493 | str.ptr = regname; | |
494 | str.length = len; | |
495 | write_exp_string (str); | |
496 | write_exp_elt_opcode (OP_REGISTER); | |
497 | ||
498 | if (indirect_p) | |
499 | { | |
500 | if (disp_p) | |
501 | write_exp_elt_opcode (BINOP_ADD); | |
502 | ||
503 | /* Casting to the expected type. */ | |
504 | write_exp_elt_opcode (UNOP_CAST); | |
505 | write_exp_elt_type (lookup_pointer_type (p->arg_type)); | |
506 | write_exp_elt_opcode (UNOP_CAST); | |
507 | ||
508 | write_exp_elt_opcode (UNOP_IND); | |
509 | } | |
510 | ||
511 | /* Getting rid of the register name suffix. */ | |
512 | if (reg_suffix) | |
513 | { | |
514 | if (strncmp (p->arg, reg_suffix, reg_suffix_len) != 0) | |
515 | error (_("Missing register name suffix `%s' on expression `%s'."), | |
516 | reg_suffix, p->saved_arg); | |
517 | ||
518 | p->arg += reg_suffix_len; | |
519 | } | |
520 | ||
521 | /* Getting rid of the register indirection suffix. */ | |
522 | if (indirect_p && reg_ind_suffix) | |
523 | { | |
524 | if (strncmp (p->arg, reg_ind_suffix, reg_ind_suffix_len) != 0) | |
525 | error (_("Missing indirection suffix `%s' on expression `%s'."), | |
526 | reg_ind_suffix, p->saved_arg); | |
527 | ||
528 | p->arg += reg_ind_suffix_len; | |
529 | } | |
530 | } | |
531 | ||
532 | /* This function is responsible for parsing a single operand. | |
533 | ||
534 | A single operand can be: | |
535 | ||
536 | - an unary operation (e.g., `-5', `~2', or even with subexpressions | |
537 | like `-(2 + 1)') | |
538 | - a register displacement, which will be treated as a register | |
539 | operand (e.g., `-4(%eax)' on x86) | |
540 | - a numeric constant, or | |
541 | - a register operand (see function `stap_parse_register_operand') | |
542 | ||
543 | The function also calls special-handling functions to deal with | |
544 | unrecognized operands, allowing arch-specific parsers to be | |
545 | created. */ | |
546 | ||
547 | static void | |
548 | stap_parse_single_operand (struct stap_parse_info *p) | |
549 | { | |
550 | struct gdbarch *gdbarch = p->gdbarch; | |
551 | ||
552 | /* Prefixes for the parser. */ | |
553 | const char *const_prefix = gdbarch_stap_integer_prefix (gdbarch); | |
554 | const char *reg_prefix = gdbarch_stap_register_prefix (gdbarch); | |
555 | const char *reg_ind_prefix | |
556 | = gdbarch_stap_register_indirection_prefix (gdbarch); | |
557 | int const_prefix_len = const_prefix ? strlen (const_prefix) : 0; | |
558 | int reg_prefix_len = reg_prefix ? strlen (reg_prefix) : 0; | |
559 | int reg_ind_prefix_len = reg_ind_prefix ? strlen (reg_ind_prefix) : 0; | |
560 | ||
561 | /* Suffixes for the parser. */ | |
562 | const char *const_suffix = gdbarch_stap_integer_suffix (gdbarch); | |
55aa24fb | 563 | int const_suffix_len = const_suffix ? strlen (const_suffix) : 0; |
55aa24fb SDJ |
564 | |
565 | /* We first try to parse this token as a "special token". */ | |
566 | if (gdbarch_stap_parse_special_token_p (gdbarch)) | |
567 | { | |
568 | int ret = gdbarch_stap_parse_special_token (gdbarch, p); | |
569 | ||
570 | if (ret) | |
571 | { | |
572 | /* If the return value of the above function is not zero, | |
573 | it means it successfully parsed the special token. | |
574 | ||
575 | If it is NULL, we try to parse it using our method. */ | |
576 | return; | |
577 | } | |
578 | } | |
579 | ||
580 | if (*p->arg == '-' || *p->arg == '~' || *p->arg == '+') | |
581 | { | |
582 | char c = *p->arg; | |
583 | int number; | |
584 | ||
585 | /* We use this variable to do a lookahead. */ | |
586 | const char *tmp = p->arg; | |
587 | ||
588 | ++tmp; | |
589 | ||
590 | /* This is an unary operation. Here is a list of allowed tokens | |
591 | here: | |
592 | ||
593 | - numeric literal; | |
594 | - number (from register displacement) | |
595 | - subexpression (beginning with `(') | |
596 | ||
597 | We handle the register displacement here, and the other cases | |
598 | recursively. */ | |
599 | if (p->inside_paren_p) | |
600 | tmp = skip_spaces_const (tmp); | |
601 | ||
602 | if (isdigit (*tmp)) | |
a0bcdaa7 PA |
603 | { |
604 | char *endp; | |
605 | ||
606 | number = strtol (tmp, &endp, 10); | |
607 | tmp = endp; | |
608 | } | |
55aa24fb SDJ |
609 | |
610 | if (!reg_ind_prefix | |
611 | || strncmp (tmp, reg_ind_prefix, reg_ind_prefix_len) != 0) | |
612 | { | |
613 | /* This is not a displacement. We skip the operator, and deal | |
614 | with it later. */ | |
615 | ++p->arg; | |
616 | stap_parse_argument_conditionally (p); | |
617 | if (c == '-') | |
618 | write_exp_elt_opcode (UNOP_NEG); | |
619 | else if (c == '~') | |
620 | write_exp_elt_opcode (UNOP_COMPLEMENT); | |
621 | } | |
622 | else | |
623 | { | |
624 | /* If we are here, it means it is a displacement. The only | |
625 | operations allowed here are `-' and `+'. */ | |
626 | if (c == '~') | |
627 | error (_("Invalid operator `%c' for register displacement " | |
628 | "on expression `%s'."), c, p->saved_arg); | |
629 | ||
630 | stap_parse_register_operand (p); | |
631 | } | |
632 | } | |
633 | else if (isdigit (*p->arg)) | |
634 | { | |
635 | /* A temporary variable, needed for lookahead. */ | |
636 | const char *tmp = p->arg; | |
a0bcdaa7 | 637 | char *endp; |
55aa24fb SDJ |
638 | long number; |
639 | ||
640 | /* We can be dealing with a numeric constant (if `const_prefix' is | |
641 | NULL), or with a register displacement. */ | |
a0bcdaa7 PA |
642 | number = strtol (tmp, &endp, 10); |
643 | tmp = endp; | |
55aa24fb SDJ |
644 | |
645 | if (p->inside_paren_p) | |
646 | tmp = skip_spaces_const (tmp); | |
647 | if (!const_prefix && reg_ind_prefix | |
648 | && strncmp (tmp, reg_ind_prefix, reg_ind_prefix_len) != 0) | |
649 | { | |
650 | /* We are dealing with a numeric constant. */ | |
651 | write_exp_elt_opcode (OP_LONG); | |
652 | write_exp_elt_type (builtin_type (gdbarch)->builtin_long); | |
653 | write_exp_elt_longcst (number); | |
654 | write_exp_elt_opcode (OP_LONG); | |
655 | ||
656 | p->arg = tmp; | |
657 | ||
658 | if (const_suffix) | |
659 | { | |
660 | if (strncmp (p->arg, const_suffix, const_suffix_len) == 0) | |
661 | p->arg += const_suffix_len; | |
662 | else | |
663 | error (_("Invalid constant suffix on expression `%s'."), | |
664 | p->saved_arg); | |
665 | } | |
666 | } | |
667 | else if (reg_ind_prefix | |
668 | && strncmp (tmp, reg_ind_prefix, reg_ind_prefix_len) == 0) | |
669 | stap_parse_register_operand (p); | |
670 | else | |
671 | error (_("Unknown numeric token on expression `%s'."), | |
672 | p->saved_arg); | |
673 | } | |
674 | else if (const_prefix | |
675 | && strncmp (p->arg, const_prefix, const_prefix_len) == 0) | |
676 | { | |
677 | /* We are dealing with a numeric constant. */ | |
678 | long number; | |
a0bcdaa7 | 679 | char *endp; |
55aa24fb SDJ |
680 | |
681 | p->arg += const_prefix_len; | |
a0bcdaa7 PA |
682 | number = strtol (p->arg, &endp, 10); |
683 | p->arg = endp; | |
55aa24fb SDJ |
684 | |
685 | write_exp_elt_opcode (OP_LONG); | |
686 | write_exp_elt_type (builtin_type (gdbarch)->builtin_long); | |
687 | write_exp_elt_longcst (number); | |
688 | write_exp_elt_opcode (OP_LONG); | |
689 | ||
690 | if (const_suffix) | |
691 | { | |
692 | if (strncmp (p->arg, const_suffix, const_suffix_len) == 0) | |
693 | p->arg += const_suffix_len; | |
694 | else | |
695 | error (_("Invalid constant suffix on expression `%s'."), | |
696 | p->saved_arg); | |
697 | } | |
698 | } | |
699 | else if ((reg_prefix | |
700 | && strncmp (p->arg, reg_prefix, reg_prefix_len) == 0) | |
701 | || (reg_ind_prefix | |
702 | && strncmp (p->arg, reg_ind_prefix, reg_ind_prefix_len) == 0)) | |
703 | stap_parse_register_operand (p); | |
704 | else | |
705 | error (_("Operator `%c' not recognized on expression `%s'."), | |
706 | *p->arg, p->saved_arg); | |
707 | } | |
708 | ||
709 | /* This function parses an argument conditionally, based on single or | |
710 | non-single operands. A non-single operand would be a parenthesized | |
711 | expression (e.g., `(2 + 1)'), and a single operand is anything that | |
712 | starts with `-', `~', `+' (i.e., unary operators), a digit, or | |
713 | something recognized by `gdbarch_stap_is_single_operand'. */ | |
714 | ||
715 | static void | |
716 | stap_parse_argument_conditionally (struct stap_parse_info *p) | |
717 | { | |
718 | if (*p->arg == '-' || *p->arg == '~' || *p->arg == '+' /* Unary. */ | |
719 | || isdigit (*p->arg) | |
720 | || gdbarch_stap_is_single_operand (p->gdbarch, p->arg)) | |
721 | stap_parse_single_operand (p); | |
722 | else if (*p->arg == '(') | |
723 | { | |
724 | /* We are dealing with a parenthesized operand. It means we | |
725 | have to parse it as it was a separate expression, without | |
726 | left-side or precedence. */ | |
727 | ++p->arg; | |
728 | p->arg = skip_spaces_const (p->arg); | |
729 | ++p->inside_paren_p; | |
730 | ||
731 | stap_parse_argument_1 (p, 0, STAP_OPERAND_PREC_NONE); | |
732 | ||
733 | --p->inside_paren_p; | |
734 | if (*p->arg != ')') | |
735 | error (_("Missign close-paren on expression `%s'."), | |
736 | p->saved_arg); | |
737 | ||
738 | ++p->arg; | |
739 | if (p->inside_paren_p) | |
740 | p->arg = skip_spaces_const (p->arg); | |
741 | } | |
742 | else | |
743 | error (_("Cannot parse expression `%s'."), p->saved_arg); | |
744 | } | |
745 | ||
746 | /* Helper function for `stap_parse_argument'. Please, see its comments to | |
747 | better understand what this function does. */ | |
748 | ||
749 | static void | |
750 | stap_parse_argument_1 (struct stap_parse_info *p, int has_lhs, | |
751 | enum stap_operand_prec prec) | |
752 | { | |
753 | /* This is an operator-precedence parser. | |
754 | ||
755 | We work with left- and right-sides of expressions, and | |
756 | parse them depending on the precedence of the operators | |
757 | we find. */ | |
758 | ||
759 | if (p->inside_paren_p) | |
760 | p->arg = skip_spaces_const (p->arg); | |
761 | ||
762 | if (!has_lhs) | |
763 | { | |
764 | /* We were called without a left-side, either because this is the | |
765 | first call, or because we were called to parse a parenthesized | |
766 | expression. It doesn't really matter; we have to parse the | |
767 | left-side in order to continue the process. */ | |
768 | stap_parse_argument_conditionally (p); | |
769 | } | |
770 | ||
771 | /* Start to parse the right-side, and to "join" left and right sides | |
772 | depending on the operation specified. | |
773 | ||
774 | This loop shall continue until we run out of characters in the input, | |
775 | or until we find a close-parenthesis, which means that we've reached | |
776 | the end of a sub-expression. */ | |
777 | while (p->arg && *p->arg && *p->arg != ')' && !isspace (*p->arg)) | |
778 | { | |
779 | const char *tmp_exp_buf; | |
780 | enum exp_opcode opcode; | |
781 | enum stap_operand_prec cur_prec; | |
782 | ||
fcf57f19 | 783 | if (!stap_is_operator (p->arg)) |
55aa24fb SDJ |
784 | error (_("Invalid operator `%c' on expression `%s'."), *p->arg, |
785 | p->saved_arg); | |
786 | ||
787 | /* We have to save the current value of the expression buffer because | |
788 | the `stap_get_opcode' modifies it in order to get the current | |
789 | operator. If this operator's precedence is lower than PREC, we | |
790 | should return and not advance the expression buffer pointer. */ | |
791 | tmp_exp_buf = p->arg; | |
fcf57f19 | 792 | opcode = stap_get_opcode (&tmp_exp_buf); |
55aa24fb SDJ |
793 | |
794 | cur_prec = stap_get_operator_prec (opcode); | |
795 | if (cur_prec < prec) | |
796 | { | |
797 | /* If the precedence of the operator that we are seeing now is | |
798 | lower than the precedence of the first operator seen before | |
799 | this parsing process began, it means we should stop parsing | |
800 | and return. */ | |
801 | break; | |
802 | } | |
803 | ||
804 | p->arg = tmp_exp_buf; | |
805 | if (p->inside_paren_p) | |
806 | p->arg = skip_spaces_const (p->arg); | |
807 | ||
808 | /* Parse the right-side of the expression. */ | |
809 | stap_parse_argument_conditionally (p); | |
810 | ||
811 | /* While we still have operators, try to parse another | |
812 | right-side, but using the current right-side as a left-side. */ | |
fcf57f19 | 813 | while (*p->arg && stap_is_operator (p->arg)) |
55aa24fb SDJ |
814 | { |
815 | enum exp_opcode lookahead_opcode; | |
816 | enum stap_operand_prec lookahead_prec; | |
817 | ||
818 | /* Saving the current expression buffer position. The explanation | |
819 | is the same as above. */ | |
820 | tmp_exp_buf = p->arg; | |
fcf57f19 | 821 | lookahead_opcode = stap_get_opcode (&tmp_exp_buf); |
55aa24fb SDJ |
822 | lookahead_prec = stap_get_operator_prec (lookahead_opcode); |
823 | ||
824 | if (lookahead_prec <= prec) | |
825 | { | |
826 | /* If we are dealing with an operator whose precedence is lower | |
827 | than the first one, just abandon the attempt. */ | |
828 | break; | |
829 | } | |
830 | ||
831 | /* Parse the right-side of the expression, but since we already | |
832 | have a left-side at this point, set `has_lhs' to 1. */ | |
833 | stap_parse_argument_1 (p, 1, lookahead_prec); | |
834 | } | |
835 | ||
836 | write_exp_elt_opcode (opcode); | |
837 | } | |
838 | } | |
839 | ||
840 | /* Parse a probe's argument. | |
841 | ||
842 | Assuming that: | |
843 | ||
844 | LP = literal integer prefix | |
845 | LS = literal integer suffix | |
846 | ||
847 | RP = register prefix | |
848 | RS = register suffix | |
849 | ||
850 | RIP = register indirection prefix | |
851 | RIS = register indirection suffix | |
852 | ||
853 | This routine assumes that arguments' tokens are of the form: | |
854 | ||
855 | - [LP] NUMBER [LS] | |
856 | - [RP] REGISTER [RS] | |
857 | - [RIP] [RP] REGISTER [RS] [RIS] | |
858 | - If we find a number without LP, we try to parse it as a literal integer | |
859 | constant (if LP == NULL), or as a register displacement. | |
860 | - We count parenthesis, and only skip whitespaces if we are inside them. | |
861 | - If we find an operator, we skip it. | |
862 | ||
863 | This function can also call a special function that will try to match | |
864 | unknown tokens. It will return 1 if the argument has been parsed | |
865 | successfully, or zero otherwise. */ | |
866 | ||
867 | static struct expression * | |
868 | stap_parse_argument (const char **arg, struct type *atype, | |
869 | struct gdbarch *gdbarch) | |
870 | { | |
871 | struct stap_parse_info p; | |
55aa24fb SDJ |
872 | struct cleanup *back_to; |
873 | ||
874 | /* We need to initialize the expression buffer, in order to begin | |
875 | our parsing efforts. The language here does not matter, since we | |
876 | are using our own parser. */ | |
877 | initialize_expout (10, current_language, gdbarch); | |
878 | back_to = make_cleanup (free_current_contents, &expout); | |
879 | ||
880 | p.saved_arg = *arg; | |
881 | p.arg = *arg; | |
882 | p.arg_type = atype; | |
883 | p.gdbarch = gdbarch; | |
884 | p.inside_paren_p = 0; | |
885 | ||
886 | stap_parse_argument_1 (&p, 0, STAP_OPERAND_PREC_NONE); | |
887 | ||
888 | discard_cleanups (back_to); | |
889 | ||
890 | gdb_assert (p.inside_paren_p == 0); | |
891 | ||
892 | /* Casting the final expression to the appropriate type. */ | |
893 | write_exp_elt_opcode (UNOP_CAST); | |
894 | write_exp_elt_type (atype); | |
895 | write_exp_elt_opcode (UNOP_CAST); | |
896 | ||
897 | reallocate_expout (); | |
898 | ||
899 | p.arg = skip_spaces_const (p.arg); | |
900 | *arg = p.arg; | |
901 | ||
902 | return expout; | |
903 | } | |
904 | ||
905 | /* Function which parses an argument string from PROBE, correctly splitting | |
906 | the arguments and storing their information in properly ways. | |
907 | ||
908 | Consider the following argument string (x86 syntax): | |
909 | ||
910 | `4@%eax 4@$10' | |
911 | ||
912 | We have two arguments, `%eax' and `$10', both with 32-bit unsigned bitness. | |
913 | This function basically handles them, properly filling some structures with | |
914 | this information. */ | |
915 | ||
916 | static void | |
6bac7473 | 917 | stap_parse_probe_arguments (struct stap_probe *probe) |
55aa24fb SDJ |
918 | { |
919 | const char *cur; | |
6bac7473 | 920 | struct gdbarch *gdbarch = get_objfile_arch (probe->p.objfile); |
55aa24fb SDJ |
921 | |
922 | gdb_assert (!probe->args_parsed); | |
923 | cur = probe->args_u.text; | |
924 | probe->args_parsed = 1; | |
925 | probe->args_u.vec = NULL; | |
926 | ||
927 | if (!cur || !*cur || *cur == ':') | |
928 | return; | |
929 | ||
930 | while (*cur) | |
931 | { | |
932 | struct stap_probe_arg arg; | |
933 | enum stap_arg_bitness b; | |
934 | int got_minus = 0; | |
935 | struct expression *expr; | |
936 | ||
937 | memset (&arg, 0, sizeof (arg)); | |
938 | ||
939 | /* We expect to find something like: | |
940 | ||
941 | N@OP | |
942 | ||
943 | Where `N' can be [+,-][4,8]. This is not mandatory, so | |
944 | we check it here. If we don't find it, go to the next | |
945 | state. */ | |
946 | if ((*cur == '-' && cur[1] && cur[2] != '@') | |
947 | && cur[1] != '@') | |
948 | arg.bitness = STAP_ARG_BITNESS_UNDEFINED; | |
949 | else | |
950 | { | |
951 | if (*cur == '-') | |
952 | { | |
953 | /* Discard the `-'. */ | |
954 | ++cur; | |
955 | got_minus = 1; | |
956 | } | |
957 | ||
958 | if (*cur == '4') | |
959 | b = (got_minus ? STAP_ARG_BITNESS_32BIT_SIGNED | |
960 | : STAP_ARG_BITNESS_32BIT_UNSIGNED); | |
961 | else if (*cur == '8') | |
962 | b = (got_minus ? STAP_ARG_BITNESS_64BIT_SIGNED | |
963 | : STAP_ARG_BITNESS_64BIT_UNSIGNED); | |
964 | else | |
965 | { | |
966 | /* We have an error, because we don't expect anything | |
967 | except 4 and 8. */ | |
968 | complaint (&symfile_complaints, | |
969 | _("unrecognized bitness `%c' for probe `%s'"), | |
970 | *cur, probe->p.name); | |
971 | return; | |
972 | } | |
973 | ||
974 | arg.bitness = b; | |
975 | arg.atype = stap_get_expected_argument_type (gdbarch, b); | |
976 | ||
977 | /* Discard the number and the `@' sign. */ | |
978 | cur += 2; | |
979 | } | |
980 | ||
981 | expr = stap_parse_argument (&cur, arg.atype, gdbarch); | |
982 | ||
983 | if (stap_expression_debug) | |
984 | dump_raw_expression (expr, gdb_stdlog, | |
985 | "before conversion to prefix form"); | |
986 | ||
987 | prefixify_expression (expr); | |
988 | ||
989 | if (stap_expression_debug) | |
990 | dump_prefix_expression (expr, gdb_stdlog); | |
991 | ||
992 | arg.aexpr = expr; | |
993 | ||
994 | /* Start it over again. */ | |
995 | cur = skip_spaces_const (cur); | |
996 | ||
997 | VEC_safe_push (stap_probe_arg_s, probe->args_u.vec, &arg); | |
998 | } | |
999 | } | |
1000 | ||
1001 | /* Given PROBE, returns the number of arguments present in that probe's | |
1002 | argument string. */ | |
1003 | ||
1004 | static unsigned | |
6bac7473 | 1005 | stap_get_probe_argument_count (struct probe *probe_generic) |
55aa24fb SDJ |
1006 | { |
1007 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
1008 | ||
1009 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1010 | ||
1011 | if (!probe->args_parsed) | |
25f9533e SDJ |
1012 | { |
1013 | if (probe_generic->pops->can_evaluate_probe_arguments (probe_generic)) | |
1014 | stap_parse_probe_arguments (probe); | |
1015 | else | |
1016 | { | |
1017 | static int have_warned_stap_incomplete = 0; | |
1018 | ||
1019 | if (!have_warned_stap_incomplete) | |
1020 | { | |
1021 | warning (_( | |
1022 | "The SystemTap SDT probe support is not fully implemented on this target;\n" | |
1023 | "you will not be able to inspect the arguments of the probes.\n" | |
1024 | "Please report a bug against GDB requesting a port to this target.")); | |
1025 | have_warned_stap_incomplete = 1; | |
1026 | } | |
1027 | ||
1028 | /* Marking the arguments as "already parsed". */ | |
1029 | probe->args_u.vec = NULL; | |
1030 | probe->args_parsed = 1; | |
1031 | } | |
1032 | } | |
55aa24fb SDJ |
1033 | |
1034 | gdb_assert (probe->args_parsed); | |
1035 | return VEC_length (stap_probe_arg_s, probe->args_u.vec); | |
1036 | } | |
1037 | ||
1038 | /* Return 1 if OP is a valid operator inside a probe argument, or zero | |
1039 | otherwise. */ | |
1040 | ||
1041 | static int | |
fcf57f19 | 1042 | stap_is_operator (const char *op) |
55aa24fb | 1043 | { |
fcf57f19 SDJ |
1044 | int ret = 1; |
1045 | ||
1046 | switch (*op) | |
1047 | { | |
1048 | case '*': | |
1049 | case '/': | |
1050 | case '%': | |
1051 | case '^': | |
1052 | case '!': | |
1053 | case '+': | |
1054 | case '-': | |
1055 | case '<': | |
1056 | case '>': | |
1057 | case '|': | |
1058 | case '&': | |
1059 | break; | |
1060 | ||
1061 | case '=': | |
1062 | if (op[1] != '=') | |
1063 | ret = 0; | |
1064 | break; | |
1065 | ||
1066 | default: | |
1067 | /* We didn't find any operator. */ | |
1068 | ret = 0; | |
1069 | } | |
1070 | ||
1071 | return ret; | |
55aa24fb SDJ |
1072 | } |
1073 | ||
1074 | static struct stap_probe_arg * | |
6bac7473 | 1075 | stap_get_arg (struct stap_probe *probe, unsigned n) |
55aa24fb SDJ |
1076 | { |
1077 | if (!probe->args_parsed) | |
6bac7473 | 1078 | stap_parse_probe_arguments (probe); |
55aa24fb SDJ |
1079 | |
1080 | return VEC_index (stap_probe_arg_s, probe->args_u.vec, n); | |
1081 | } | |
1082 | ||
25f9533e SDJ |
1083 | /* Implement the `can_evaluate_probe_arguments' method of probe_ops. */ |
1084 | ||
1085 | static int | |
1086 | stap_can_evaluate_probe_arguments (struct probe *probe_generic) | |
1087 | { | |
1088 | struct stap_probe *stap_probe = (struct stap_probe *) probe_generic; | |
df6d5441 | 1089 | struct gdbarch *gdbarch = get_objfile_arch (stap_probe->p.objfile); |
25f9533e SDJ |
1090 | |
1091 | /* For SystemTap probes, we have to guarantee that the method | |
1092 | stap_is_single_operand is defined on gdbarch. If it is not, then it | |
1093 | means that argument evaluation is not implemented on this target. */ | |
1094 | return gdbarch_stap_is_single_operand_p (gdbarch); | |
1095 | } | |
1096 | ||
55aa24fb SDJ |
1097 | /* Evaluate the probe's argument N (indexed from 0), returning a value |
1098 | corresponding to it. Assertion is thrown if N does not exist. */ | |
1099 | ||
1100 | static struct value * | |
6bac7473 | 1101 | stap_evaluate_probe_argument (struct probe *probe_generic, unsigned n) |
55aa24fb SDJ |
1102 | { |
1103 | struct stap_probe *stap_probe = (struct stap_probe *) probe_generic; | |
1104 | struct stap_probe_arg *arg; | |
1105 | int pos = 0; | |
1106 | ||
1107 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1108 | ||
6bac7473 | 1109 | arg = stap_get_arg (stap_probe, n); |
55aa24fb SDJ |
1110 | return evaluate_subexp_standard (arg->atype, arg->aexpr, &pos, EVAL_NORMAL); |
1111 | } | |
1112 | ||
1113 | /* Compile the probe's argument N (indexed from 0) to agent expression. | |
1114 | Assertion is thrown if N does not exist. */ | |
1115 | ||
1116 | static void | |
6bac7473 SDJ |
1117 | stap_compile_to_ax (struct probe *probe_generic, struct agent_expr *expr, |
1118 | struct axs_value *value, unsigned n) | |
55aa24fb SDJ |
1119 | { |
1120 | struct stap_probe *stap_probe = (struct stap_probe *) probe_generic; | |
1121 | struct stap_probe_arg *arg; | |
1122 | union exp_element *pc; | |
1123 | ||
1124 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1125 | ||
6bac7473 | 1126 | arg = stap_get_arg (stap_probe, n); |
55aa24fb SDJ |
1127 | |
1128 | pc = arg->aexpr->elts; | |
1129 | gen_expr (arg->aexpr, &pc, expr, value); | |
1130 | ||
1131 | require_rvalue (expr, value); | |
1132 | value->type = arg->atype; | |
1133 | } | |
1134 | ||
1135 | /* Destroy (free) the data related to PROBE. PROBE memory itself is not feed | |
1136 | as it is allocated from OBJFILE_OBSTACK. */ | |
1137 | ||
1138 | static void | |
1139 | stap_probe_destroy (struct probe *probe_generic) | |
1140 | { | |
1141 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
1142 | ||
1143 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1144 | ||
1145 | if (probe->args_parsed) | |
1146 | { | |
1147 | struct stap_probe_arg *arg; | |
1148 | int ix; | |
1149 | ||
1150 | for (ix = 0; VEC_iterate (stap_probe_arg_s, probe->args_u.vec, ix, arg); | |
1151 | ++ix) | |
1152 | xfree (arg->aexpr); | |
1153 | VEC_free (stap_probe_arg_s, probe->args_u.vec); | |
1154 | } | |
1155 | } | |
1156 | ||
1157 | \f | |
1158 | ||
1159 | /* This is called to compute the value of one of the $_probe_arg* | |
1160 | convenience variables. */ | |
1161 | ||
1162 | static struct value * | |
1163 | compute_probe_arg (struct gdbarch *arch, struct internalvar *ivar, | |
1164 | void *data) | |
1165 | { | |
1166 | struct frame_info *frame = get_selected_frame (_("No frame selected")); | |
1167 | CORE_ADDR pc = get_frame_pc (frame); | |
1168 | int sel = (int) (uintptr_t) data; | |
55aa24fb | 1169 | struct probe *pc_probe; |
6bac7473 | 1170 | const struct sym_probe_fns *pc_probe_fns; |
55aa24fb SDJ |
1171 | unsigned n_args; |
1172 | ||
1173 | /* SEL == -1 means "_probe_argc". */ | |
1174 | gdb_assert (sel >= -1); | |
1175 | ||
6bac7473 | 1176 | pc_probe = find_probe_by_pc (pc); |
55aa24fb SDJ |
1177 | if (pc_probe == NULL) |
1178 | error (_("No SystemTap probe at PC %s"), core_addr_to_string (pc)); | |
1179 | ||
6bac7473 SDJ |
1180 | gdb_assert (pc_probe->objfile != NULL); |
1181 | gdb_assert (pc_probe->objfile->sf != NULL); | |
1182 | gdb_assert (pc_probe->objfile->sf->sym_probe_fns != NULL); | |
1183 | ||
1184 | pc_probe_fns = pc_probe->objfile->sf->sym_probe_fns; | |
1185 | ||
1186 | n_args = pc_probe_fns->sym_get_probe_argument_count (pc_probe); | |
55aa24fb SDJ |
1187 | if (sel == -1) |
1188 | return value_from_longest (builtin_type (arch)->builtin_int, n_args); | |
1189 | ||
1190 | if (sel >= n_args) | |
1191 | error (_("Invalid probe argument %d -- probe has %u arguments available"), | |
1192 | sel, n_args); | |
1193 | ||
6bac7473 | 1194 | return pc_probe_fns->sym_evaluate_probe_argument (pc_probe, sel); |
55aa24fb SDJ |
1195 | } |
1196 | ||
1197 | /* This is called to compile one of the $_probe_arg* convenience | |
1198 | variables into an agent expression. */ | |
1199 | ||
1200 | static void | |
1201 | compile_probe_arg (struct internalvar *ivar, struct agent_expr *expr, | |
1202 | struct axs_value *value, void *data) | |
1203 | { | |
1204 | CORE_ADDR pc = expr->scope; | |
1205 | int sel = (int) (uintptr_t) data; | |
55aa24fb | 1206 | struct probe *pc_probe; |
6bac7473 | 1207 | const struct sym_probe_fns *pc_probe_fns; |
2b963b68 | 1208 | int n_args; |
55aa24fb SDJ |
1209 | |
1210 | /* SEL == -1 means "_probe_argc". */ | |
1211 | gdb_assert (sel >= -1); | |
1212 | ||
6bac7473 | 1213 | pc_probe = find_probe_by_pc (pc); |
55aa24fb SDJ |
1214 | if (pc_probe == NULL) |
1215 | error (_("No SystemTap probe at PC %s"), core_addr_to_string (pc)); | |
1216 | ||
6bac7473 SDJ |
1217 | gdb_assert (pc_probe->objfile != NULL); |
1218 | gdb_assert (pc_probe->objfile->sf != NULL); | |
1219 | gdb_assert (pc_probe->objfile->sf->sym_probe_fns != NULL); | |
1220 | ||
1221 | pc_probe_fns = pc_probe->objfile->sf->sym_probe_fns; | |
1222 | ||
2b963b68 | 1223 | n_args = pc_probe_fns->sym_get_probe_argument_count (pc_probe); |
6bac7473 | 1224 | |
55aa24fb SDJ |
1225 | if (sel == -1) |
1226 | { | |
1227 | value->kind = axs_rvalue; | |
1228 | value->type = builtin_type (expr->gdbarch)->builtin_int; | |
2b963b68 | 1229 | ax_const_l (expr, n_args); |
55aa24fb SDJ |
1230 | return; |
1231 | } | |
1232 | ||
1233 | gdb_assert (sel >= 0); | |
2b963b68 | 1234 | if (sel >= n_args) |
55aa24fb | 1235 | error (_("Invalid probe argument %d -- probe has %d arguments available"), |
2b963b68 | 1236 | sel, n_args); |
55aa24fb | 1237 | |
6bac7473 | 1238 | pc_probe_fns->sym_compile_to_ax (pc_probe, expr, value, sel); |
55aa24fb SDJ |
1239 | } |
1240 | ||
1241 | \f | |
1242 | ||
1243 | /* Set or clear a SystemTap semaphore. ADDRESS is the semaphore's | |
1244 | address. SET is zero if the semaphore should be cleared, or one | |
1245 | if it should be set. This is a helper function for `stap_semaphore_down' | |
1246 | and `stap_semaphore_up'. */ | |
1247 | ||
1248 | static void | |
1249 | stap_modify_semaphore (CORE_ADDR address, int set, struct gdbarch *gdbarch) | |
1250 | { | |
1251 | gdb_byte bytes[sizeof (LONGEST)]; | |
1252 | /* The ABI specifies "unsigned short". */ | |
1253 | struct type *type = builtin_type (gdbarch)->builtin_unsigned_short; | |
1254 | ULONGEST value; | |
1255 | ||
1256 | if (address == 0) | |
1257 | return; | |
1258 | ||
1259 | /* Swallow errors. */ | |
1260 | if (target_read_memory (address, bytes, TYPE_LENGTH (type)) != 0) | |
1261 | { | |
1262 | warning (_("Could not read the value of a SystemTap semaphore.")); | |
1263 | return; | |
1264 | } | |
1265 | ||
1266 | value = extract_unsigned_integer (bytes, TYPE_LENGTH (type), | |
1267 | gdbarch_byte_order (gdbarch)); | |
1268 | /* Note that we explicitly don't worry about overflow or | |
1269 | underflow. */ | |
1270 | if (set) | |
1271 | ++value; | |
1272 | else | |
1273 | --value; | |
1274 | ||
1275 | store_unsigned_integer (bytes, TYPE_LENGTH (type), | |
1276 | gdbarch_byte_order (gdbarch), value); | |
1277 | ||
1278 | if (target_write_memory (address, bytes, TYPE_LENGTH (type)) != 0) | |
1279 | warning (_("Could not write the value of a SystemTap semaphore.")); | |
1280 | } | |
1281 | ||
1282 | /* Set a SystemTap semaphore. SEM is the semaphore's address. Semaphores | |
1283 | act as reference counters, so calls to this function must be paired with | |
1284 | calls to `stap_semaphore_down'. | |
1285 | ||
1286 | This function and `stap_semaphore_down' race with another tool changing | |
1287 | the probes, but that is too rare to care. */ | |
1288 | ||
1289 | static void | |
1290 | stap_set_semaphore (struct probe *probe_generic, struct gdbarch *gdbarch) | |
1291 | { | |
1292 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
1293 | ||
1294 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1295 | ||
1296 | stap_modify_semaphore (probe->sem_addr, 1, gdbarch); | |
1297 | } | |
1298 | ||
1299 | /* Clear a SystemTap semaphore. SEM is the semaphore's address. */ | |
1300 | ||
1301 | static void | |
1302 | stap_clear_semaphore (struct probe *probe_generic, struct gdbarch *gdbarch) | |
1303 | { | |
1304 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
1305 | ||
1306 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1307 | ||
1308 | stap_modify_semaphore (probe->sem_addr, 0, gdbarch); | |
1309 | } | |
1310 | ||
1311 | /* Implementation of `$_probe_arg*' set of variables. */ | |
1312 | ||
1313 | static const struct internalvar_funcs probe_funcs = | |
1314 | { | |
1315 | compute_probe_arg, | |
1316 | compile_probe_arg, | |
1317 | NULL | |
1318 | }; | |
1319 | ||
1320 | /* Helper function that parses the information contained in a | |
1321 | SystemTap's probe. Basically, the information consists in: | |
1322 | ||
1323 | - Probe's PC address; | |
1324 | - Link-time section address of `.stapsdt.base' section; | |
1325 | - Link-time address of the semaphore variable, or ZERO if the | |
1326 | probe doesn't have an associated semaphore; | |
1327 | - Probe's provider name; | |
1328 | - Probe's name; | |
1329 | - Probe's argument format | |
1330 | ||
1331 | This function returns 1 if the handling was successful, and zero | |
1332 | otherwise. */ | |
1333 | ||
1334 | static void | |
1335 | handle_stap_probe (struct objfile *objfile, struct sdt_note *el, | |
1336 | VEC (probe_p) **probesp, CORE_ADDR base) | |
1337 | { | |
1338 | bfd *abfd = objfile->obfd; | |
1339 | int size = bfd_get_arch_size (abfd) / 8; | |
1340 | struct gdbarch *gdbarch = get_objfile_arch (objfile); | |
55aa24fb SDJ |
1341 | struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
1342 | CORE_ADDR base_ref; | |
1343 | const char *probe_args = NULL; | |
1344 | struct stap_probe *ret; | |
1345 | ||
1346 | ret = obstack_alloc (&objfile->objfile_obstack, sizeof (*ret)); | |
1347 | ret->p.pops = &stap_probe_ops; | |
6bac7473 | 1348 | ret->p.objfile = objfile; |
55aa24fb SDJ |
1349 | |
1350 | /* Provider and the name of the probe. */ | |
fe106009 | 1351 | ret->p.provider = (char *) &el->data[3 * size]; |
55aa24fb SDJ |
1352 | ret->p.name = memchr (ret->p.provider, '\0', |
1353 | (char *) el->data + el->size - ret->p.provider); | |
1354 | /* Making sure there is a name. */ | |
1355 | if (!ret->p.name) | |
1356 | { | |
1357 | complaint (&symfile_complaints, _("corrupt probe name when " | |
4262abfb JK |
1358 | "reading `%s'"), |
1359 | objfile_name (objfile)); | |
55aa24fb SDJ |
1360 | |
1361 | /* There is no way to use a probe without a name or a provider, so | |
1362 | returning zero here makes sense. */ | |
1363 | return; | |
1364 | } | |
1365 | else | |
1366 | ++ret->p.name; | |
1367 | ||
1368 | /* Retrieving the probe's address. */ | |
1369 | ret->p.address = extract_typed_address (&el->data[0], ptr_type); | |
1370 | ||
1371 | /* Link-time sh_addr of `.stapsdt.base' section. */ | |
1372 | base_ref = extract_typed_address (&el->data[size], ptr_type); | |
1373 | ||
1374 | /* Semaphore address. */ | |
1375 | ret->sem_addr = extract_typed_address (&el->data[2 * size], ptr_type); | |
1376 | ||
1377 | ret->p.address += (ANOFFSET (objfile->section_offsets, | |
1378 | SECT_OFF_TEXT (objfile)) | |
1379 | + base - base_ref); | |
1380 | if (ret->sem_addr) | |
1381 | ret->sem_addr += (ANOFFSET (objfile->section_offsets, | |
1382 | SECT_OFF_DATA (objfile)) | |
1383 | + base - base_ref); | |
1384 | ||
1385 | /* Arguments. We can only extract the argument format if there is a valid | |
1386 | name for this probe. */ | |
1387 | probe_args = memchr (ret->p.name, '\0', | |
1388 | (char *) el->data + el->size - ret->p.name); | |
1389 | ||
1390 | if (probe_args != NULL) | |
1391 | ++probe_args; | |
1392 | ||
1393 | if (probe_args == NULL || (memchr (probe_args, '\0', | |
1394 | (char *) el->data + el->size - ret->p.name) | |
1395 | != el->data + el->size - 1)) | |
1396 | { | |
1397 | complaint (&symfile_complaints, _("corrupt probe argument when " | |
4262abfb JK |
1398 | "reading `%s'"), |
1399 | objfile_name (objfile)); | |
55aa24fb SDJ |
1400 | /* If the argument string is NULL, it means some problem happened with |
1401 | it. So we return 0. */ | |
1402 | return; | |
1403 | } | |
1404 | ||
1405 | ret->args_parsed = 0; | |
1406 | ret->args_u.text = (void *) probe_args; | |
1407 | ||
1408 | /* Successfully created probe. */ | |
1409 | VEC_safe_push (probe_p, *probesp, (struct probe *) ret); | |
1410 | } | |
1411 | ||
1412 | /* Helper function which tries to find the base address of the SystemTap | |
1413 | base section named STAP_BASE_SECTION_NAME. */ | |
1414 | ||
1415 | static void | |
1416 | get_stap_base_address_1 (bfd *abfd, asection *sect, void *obj) | |
1417 | { | |
1418 | asection **ret = obj; | |
1419 | ||
1420 | if ((sect->flags & (SEC_DATA | SEC_ALLOC | SEC_HAS_CONTENTS)) | |
1421 | && sect->name && !strcmp (sect->name, STAP_BASE_SECTION_NAME)) | |
1422 | *ret = sect; | |
1423 | } | |
1424 | ||
1425 | /* Helper function which iterates over every section in the BFD file, | |
1426 | trying to find the base address of the SystemTap base section. | |
1427 | Returns 1 if found (setting BASE to the proper value), zero otherwise. */ | |
1428 | ||
1429 | static int | |
1430 | get_stap_base_address (bfd *obfd, bfd_vma *base) | |
1431 | { | |
1432 | asection *ret = NULL; | |
1433 | ||
1434 | bfd_map_over_sections (obfd, get_stap_base_address_1, (void *) &ret); | |
1435 | ||
1436 | if (!ret) | |
1437 | { | |
1438 | complaint (&symfile_complaints, _("could not obtain base address for " | |
1439 | "SystemTap section on objfile `%s'."), | |
1440 | obfd->filename); | |
1441 | return 0; | |
1442 | } | |
1443 | ||
1444 | if (base) | |
1445 | *base = ret->vma; | |
1446 | ||
1447 | return 1; | |
1448 | } | |
1449 | ||
1450 | /* Helper function for `elf_get_probes', which gathers information about all | |
1451 | SystemTap probes from OBJFILE. */ | |
1452 | ||
1453 | static void | |
1454 | stap_get_probes (VEC (probe_p) **probesp, struct objfile *objfile) | |
1455 | { | |
1456 | /* If we are here, then this is the first time we are parsing the | |
1457 | SystemTap probe's information. We basically have to count how many | |
1458 | probes the objfile has, and then fill in the necessary information | |
1459 | for each one. */ | |
1460 | bfd *obfd = objfile->obfd; | |
1461 | bfd_vma base; | |
1462 | struct sdt_note *iter; | |
1463 | unsigned save_probesp_len = VEC_length (probe_p, *probesp); | |
1464 | ||
d7333987 SDJ |
1465 | if (objfile->separate_debug_objfile_backlink != NULL) |
1466 | { | |
1467 | /* This is a .debug file, not the objfile itself. */ | |
1468 | return; | |
1469 | } | |
1470 | ||
55aa24fb SDJ |
1471 | if (!elf_tdata (obfd)->sdt_note_head) |
1472 | { | |
1473 | /* There isn't any probe here. */ | |
1474 | return; | |
1475 | } | |
1476 | ||
1477 | if (!get_stap_base_address (obfd, &base)) | |
1478 | { | |
1479 | /* There was an error finding the base address for the section. | |
1480 | Just return NULL. */ | |
1481 | return; | |
1482 | } | |
1483 | ||
1484 | /* Parsing each probe's information. */ | |
1485 | for (iter = elf_tdata (obfd)->sdt_note_head; iter; iter = iter->next) | |
1486 | { | |
1487 | /* We first have to handle all the information about the | |
1488 | probe which is present in the section. */ | |
1489 | handle_stap_probe (objfile, iter, probesp, base); | |
1490 | } | |
1491 | ||
1492 | if (save_probesp_len == VEC_length (probe_p, *probesp)) | |
1493 | { | |
1494 | /* If we are here, it means we have failed to parse every known | |
1495 | probe. */ | |
1496 | complaint (&symfile_complaints, _("could not parse SystemTap probe(s) " | |
1497 | "from inferior")); | |
1498 | return; | |
1499 | } | |
1500 | } | |
1501 | ||
1502 | static void | |
1503 | stap_relocate (struct probe *probe_generic, CORE_ADDR delta) | |
1504 | { | |
1505 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
1506 | ||
1507 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1508 | ||
1509 | probe->p.address += delta; | |
1510 | if (probe->sem_addr) | |
1511 | probe->sem_addr += delta; | |
1512 | } | |
1513 | ||
1514 | static int | |
1515 | stap_probe_is_linespec (const char **linespecp) | |
1516 | { | |
1517 | static const char *const keywords[] = { "-pstap", "-probe-stap", NULL }; | |
1518 | ||
1519 | return probe_is_linespec_by_keyword (linespecp, keywords); | |
1520 | } | |
1521 | ||
1522 | static void | |
1523 | stap_gen_info_probes_table_header (VEC (info_probe_column_s) **heads) | |
1524 | { | |
1525 | info_probe_column_s stap_probe_column; | |
1526 | ||
1527 | stap_probe_column.field_name = "semaphore"; | |
1528 | stap_probe_column.print_name = _("Semaphore"); | |
1529 | ||
1530 | VEC_safe_push (info_probe_column_s, *heads, &stap_probe_column); | |
1531 | } | |
1532 | ||
1533 | static void | |
1534 | stap_gen_info_probes_table_values (struct probe *probe_generic, | |
55aa24fb SDJ |
1535 | VEC (const_char_ptr) **ret) |
1536 | { | |
1537 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
6bac7473 | 1538 | struct gdbarch *gdbarch; |
55aa24fb SDJ |
1539 | const char *val = NULL; |
1540 | ||
1541 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1542 | ||
6bac7473 SDJ |
1543 | gdbarch = get_objfile_arch (probe->p.objfile); |
1544 | ||
55aa24fb SDJ |
1545 | if (probe->sem_addr) |
1546 | val = print_core_address (gdbarch, probe->sem_addr); | |
1547 | ||
1548 | VEC_safe_push (const_char_ptr, *ret, val); | |
1549 | } | |
1550 | ||
1551 | /* SystemTap probe_ops. */ | |
1552 | ||
1553 | static const struct probe_ops stap_probe_ops = | |
1554 | { | |
1555 | stap_probe_is_linespec, | |
1556 | stap_get_probes, | |
1557 | stap_relocate, | |
1558 | stap_get_probe_argument_count, | |
25f9533e | 1559 | stap_can_evaluate_probe_arguments, |
55aa24fb SDJ |
1560 | stap_evaluate_probe_argument, |
1561 | stap_compile_to_ax, | |
1562 | stap_set_semaphore, | |
1563 | stap_clear_semaphore, | |
1564 | stap_probe_destroy, | |
1565 | stap_gen_info_probes_table_header, | |
1566 | stap_gen_info_probes_table_values, | |
1567 | }; | |
1568 | ||
1569 | /* Implementation of the `info probes stap' command. */ | |
1570 | ||
1571 | static void | |
1572 | info_probes_stap_command (char *arg, int from_tty) | |
1573 | { | |
1574 | info_probes_for_ops (arg, from_tty, &stap_probe_ops); | |
1575 | } | |
1576 | ||
1577 | void _initialize_stap_probe (void); | |
1578 | ||
1579 | void | |
1580 | _initialize_stap_probe (void) | |
1581 | { | |
1582 | VEC_safe_push (probe_ops_cp, all_probe_ops, &stap_probe_ops); | |
1583 | ||
ccce17b0 YQ |
1584 | add_setshow_zuinteger_cmd ("stap-expression", class_maintenance, |
1585 | &stap_expression_debug, | |
1586 | _("Set SystemTap expression debugging."), | |
1587 | _("Show SystemTap expression debugging."), | |
1588 | _("When non-zero, the internal representation " | |
1589 | "of SystemTap expressions will be printed."), | |
1590 | NULL, | |
1591 | show_stapexpressiondebug, | |
1592 | &setdebuglist, &showdebuglist); | |
55aa24fb SDJ |
1593 | |
1594 | create_internalvar_type_lazy ("_probe_argc", &probe_funcs, | |
1595 | (void *) (uintptr_t) -1); | |
1596 | create_internalvar_type_lazy ("_probe_arg0", &probe_funcs, | |
1597 | (void *) (uintptr_t) 0); | |
1598 | create_internalvar_type_lazy ("_probe_arg1", &probe_funcs, | |
1599 | (void *) (uintptr_t) 1); | |
1600 | create_internalvar_type_lazy ("_probe_arg2", &probe_funcs, | |
1601 | (void *) (uintptr_t) 2); | |
1602 | create_internalvar_type_lazy ("_probe_arg3", &probe_funcs, | |
1603 | (void *) (uintptr_t) 3); | |
1604 | create_internalvar_type_lazy ("_probe_arg4", &probe_funcs, | |
1605 | (void *) (uintptr_t) 4); | |
1606 | create_internalvar_type_lazy ("_probe_arg5", &probe_funcs, | |
1607 | (void *) (uintptr_t) 5); | |
1608 | create_internalvar_type_lazy ("_probe_arg6", &probe_funcs, | |
1609 | (void *) (uintptr_t) 6); | |
1610 | create_internalvar_type_lazy ("_probe_arg7", &probe_funcs, | |
1611 | (void *) (uintptr_t) 7); | |
1612 | create_internalvar_type_lazy ("_probe_arg8", &probe_funcs, | |
1613 | (void *) (uintptr_t) 8); | |
1614 | create_internalvar_type_lazy ("_probe_arg9", &probe_funcs, | |
1615 | (void *) (uintptr_t) 9); | |
1616 | create_internalvar_type_lazy ("_probe_arg10", &probe_funcs, | |
1617 | (void *) (uintptr_t) 10); | |
1618 | create_internalvar_type_lazy ("_probe_arg11", &probe_funcs, | |
1619 | (void *) (uintptr_t) 11); | |
1620 | ||
1621 | add_cmd ("stap", class_info, info_probes_stap_command, | |
1622 | _("\ | |
1623 | Show information about SystemTap static probes.\n\ | |
1624 | Usage: info probes stap [PROVIDER [NAME [OBJECT]]]\n\ | |
1625 | Each argument is a regular expression, used to select probes.\n\ | |
1626 | PROVIDER matches probe provider names.\n\ | |
1627 | NAME matches the probe names.\n\ | |
1628 | OBJECT matches the executable or shared library name."), | |
1629 | info_probes_cmdlist_get ()); | |
1630 | ||
1631 | } |