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55aa24fb SDJ |
1 | /* SystemTap probe support for GDB. |
2 | ||
3 | Copyright (C) 2012 Free Software Foundation, Inc. | |
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 | ||
56 | static int stap_expression_debug = 0; | |
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; | |
425 | ||
426 | disp_p = 1; | |
427 | displacement = strtol (p->arg, (char **) &p->arg, 10); | |
428 | ||
429 | /* Generating the expression for the displacement. */ | |
430 | write_exp_elt_opcode (OP_LONG); | |
431 | write_exp_elt_type (builtin_type (gdbarch)->builtin_long); | |
432 | write_exp_elt_longcst (displacement); | |
433 | write_exp_elt_opcode (OP_LONG); | |
434 | if (got_minus) | |
435 | write_exp_elt_opcode (UNOP_NEG); | |
436 | } | |
437 | ||
438 | /* Getting rid of register indirection prefix. */ | |
439 | if (reg_ind_prefix | |
440 | && strncmp (p->arg, reg_ind_prefix, reg_ind_prefix_len) == 0) | |
441 | { | |
442 | indirect_p = 1; | |
443 | p->arg += reg_ind_prefix_len; | |
444 | } | |
445 | ||
446 | if (disp_p && !indirect_p) | |
447 | error (_("Invalid register displacement syntax on expression `%s'."), | |
448 | p->saved_arg); | |
449 | ||
450 | /* Getting rid of register prefix. */ | |
451 | if (reg_prefix && strncmp (p->arg, reg_prefix, reg_prefix_len) == 0) | |
452 | p->arg += reg_prefix_len; | |
453 | ||
454 | /* Now we should have only the register name. Let's extract it and get | |
455 | the associated number. */ | |
456 | start = p->arg; | |
457 | ||
458 | /* We assume the register name is composed by letters and numbers. */ | |
459 | while (isalnum (*p->arg)) | |
460 | ++p->arg; | |
461 | ||
462 | len = p->arg - start; | |
463 | ||
464 | regname = alloca (len + gdb_reg_prefix_len + gdb_reg_suffix_len + 1); | |
465 | regname[0] = '\0'; | |
466 | ||
467 | /* We only add the GDB's register prefix/suffix if we are dealing with | |
468 | a numeric register. */ | |
469 | if (gdb_reg_prefix && isdigit (*start)) | |
470 | { | |
471 | strncpy (regname, gdb_reg_prefix, gdb_reg_prefix_len); | |
472 | strncpy (regname + gdb_reg_prefix_len, start, len); | |
473 | ||
474 | if (gdb_reg_suffix) | |
475 | strncpy (regname + gdb_reg_prefix_len + len, | |
476 | gdb_reg_suffix, gdb_reg_suffix_len); | |
477 | ||
478 | len += gdb_reg_prefix_len + gdb_reg_suffix_len; | |
479 | } | |
480 | else | |
481 | strncpy (regname, start, len); | |
482 | ||
483 | regname[len] = '\0'; | |
484 | ||
485 | /* Is this a valid register name? */ | |
486 | if (user_reg_map_name_to_regnum (gdbarch, regname, len) == -1) | |
487 | error (_("Invalid register name `%s' on expression `%s'."), | |
488 | regname, p->saved_arg); | |
489 | ||
490 | write_exp_elt_opcode (OP_REGISTER); | |
491 | str.ptr = regname; | |
492 | str.length = len; | |
493 | write_exp_string (str); | |
494 | write_exp_elt_opcode (OP_REGISTER); | |
495 | ||
496 | if (indirect_p) | |
497 | { | |
498 | if (disp_p) | |
499 | write_exp_elt_opcode (BINOP_ADD); | |
500 | ||
501 | /* Casting to the expected type. */ | |
502 | write_exp_elt_opcode (UNOP_CAST); | |
503 | write_exp_elt_type (lookup_pointer_type (p->arg_type)); | |
504 | write_exp_elt_opcode (UNOP_CAST); | |
505 | ||
506 | write_exp_elt_opcode (UNOP_IND); | |
507 | } | |
508 | ||
509 | /* Getting rid of the register name suffix. */ | |
510 | if (reg_suffix) | |
511 | { | |
512 | if (strncmp (p->arg, reg_suffix, reg_suffix_len) != 0) | |
513 | error (_("Missing register name suffix `%s' on expression `%s'."), | |
514 | reg_suffix, p->saved_arg); | |
515 | ||
516 | p->arg += reg_suffix_len; | |
517 | } | |
518 | ||
519 | /* Getting rid of the register indirection suffix. */ | |
520 | if (indirect_p && reg_ind_suffix) | |
521 | { | |
522 | if (strncmp (p->arg, reg_ind_suffix, reg_ind_suffix_len) != 0) | |
523 | error (_("Missing indirection suffix `%s' on expression `%s'."), | |
524 | reg_ind_suffix, p->saved_arg); | |
525 | ||
526 | p->arg += reg_ind_suffix_len; | |
527 | } | |
528 | } | |
529 | ||
530 | /* This function is responsible for parsing a single operand. | |
531 | ||
532 | A single operand can be: | |
533 | ||
534 | - an unary operation (e.g., `-5', `~2', or even with subexpressions | |
535 | like `-(2 + 1)') | |
536 | - a register displacement, which will be treated as a register | |
537 | operand (e.g., `-4(%eax)' on x86) | |
538 | - a numeric constant, or | |
539 | - a register operand (see function `stap_parse_register_operand') | |
540 | ||
541 | The function also calls special-handling functions to deal with | |
542 | unrecognized operands, allowing arch-specific parsers to be | |
543 | created. */ | |
544 | ||
545 | static void | |
546 | stap_parse_single_operand (struct stap_parse_info *p) | |
547 | { | |
548 | struct gdbarch *gdbarch = p->gdbarch; | |
549 | ||
550 | /* Prefixes for the parser. */ | |
551 | const char *const_prefix = gdbarch_stap_integer_prefix (gdbarch); | |
552 | const char *reg_prefix = gdbarch_stap_register_prefix (gdbarch); | |
553 | const char *reg_ind_prefix | |
554 | = gdbarch_stap_register_indirection_prefix (gdbarch); | |
555 | int const_prefix_len = const_prefix ? strlen (const_prefix) : 0; | |
556 | int reg_prefix_len = reg_prefix ? strlen (reg_prefix) : 0; | |
557 | int reg_ind_prefix_len = reg_ind_prefix ? strlen (reg_ind_prefix) : 0; | |
558 | ||
559 | /* Suffixes for the parser. */ | |
560 | const char *const_suffix = gdbarch_stap_integer_suffix (gdbarch); | |
55aa24fb | 561 | int const_suffix_len = const_suffix ? strlen (const_suffix) : 0; |
55aa24fb SDJ |
562 | |
563 | /* We first try to parse this token as a "special token". */ | |
564 | if (gdbarch_stap_parse_special_token_p (gdbarch)) | |
565 | { | |
566 | int ret = gdbarch_stap_parse_special_token (gdbarch, p); | |
567 | ||
568 | if (ret) | |
569 | { | |
570 | /* If the return value of the above function is not zero, | |
571 | it means it successfully parsed the special token. | |
572 | ||
573 | If it is NULL, we try to parse it using our method. */ | |
574 | return; | |
575 | } | |
576 | } | |
577 | ||
578 | if (*p->arg == '-' || *p->arg == '~' || *p->arg == '+') | |
579 | { | |
580 | char c = *p->arg; | |
581 | int number; | |
582 | ||
583 | /* We use this variable to do a lookahead. */ | |
584 | const char *tmp = p->arg; | |
585 | ||
586 | ++tmp; | |
587 | ||
588 | /* This is an unary operation. Here is a list of allowed tokens | |
589 | here: | |
590 | ||
591 | - numeric literal; | |
592 | - number (from register displacement) | |
593 | - subexpression (beginning with `(') | |
594 | ||
595 | We handle the register displacement here, and the other cases | |
596 | recursively. */ | |
597 | if (p->inside_paren_p) | |
598 | tmp = skip_spaces_const (tmp); | |
599 | ||
600 | if (isdigit (*tmp)) | |
601 | number = strtol (tmp, (char **) &tmp, 10); | |
602 | ||
603 | if (!reg_ind_prefix | |
604 | || strncmp (tmp, reg_ind_prefix, reg_ind_prefix_len) != 0) | |
605 | { | |
606 | /* This is not a displacement. We skip the operator, and deal | |
607 | with it later. */ | |
608 | ++p->arg; | |
609 | stap_parse_argument_conditionally (p); | |
610 | if (c == '-') | |
611 | write_exp_elt_opcode (UNOP_NEG); | |
612 | else if (c == '~') | |
613 | write_exp_elt_opcode (UNOP_COMPLEMENT); | |
614 | } | |
615 | else | |
616 | { | |
617 | /* If we are here, it means it is a displacement. The only | |
618 | operations allowed here are `-' and `+'. */ | |
619 | if (c == '~') | |
620 | error (_("Invalid operator `%c' for register displacement " | |
621 | "on expression `%s'."), c, p->saved_arg); | |
622 | ||
623 | stap_parse_register_operand (p); | |
624 | } | |
625 | } | |
626 | else if (isdigit (*p->arg)) | |
627 | { | |
628 | /* A temporary variable, needed for lookahead. */ | |
629 | const char *tmp = p->arg; | |
630 | long number; | |
631 | ||
632 | /* We can be dealing with a numeric constant (if `const_prefix' is | |
633 | NULL), or with a register displacement. */ | |
634 | number = strtol (tmp, (char **) &tmp, 10); | |
635 | ||
636 | if (p->inside_paren_p) | |
637 | tmp = skip_spaces_const (tmp); | |
638 | if (!const_prefix && reg_ind_prefix | |
639 | && strncmp (tmp, reg_ind_prefix, reg_ind_prefix_len) != 0) | |
640 | { | |
641 | /* We are dealing with a numeric constant. */ | |
642 | write_exp_elt_opcode (OP_LONG); | |
643 | write_exp_elt_type (builtin_type (gdbarch)->builtin_long); | |
644 | write_exp_elt_longcst (number); | |
645 | write_exp_elt_opcode (OP_LONG); | |
646 | ||
647 | p->arg = tmp; | |
648 | ||
649 | if (const_suffix) | |
650 | { | |
651 | if (strncmp (p->arg, const_suffix, const_suffix_len) == 0) | |
652 | p->arg += const_suffix_len; | |
653 | else | |
654 | error (_("Invalid constant suffix on expression `%s'."), | |
655 | p->saved_arg); | |
656 | } | |
657 | } | |
658 | else if (reg_ind_prefix | |
659 | && strncmp (tmp, reg_ind_prefix, reg_ind_prefix_len) == 0) | |
660 | stap_parse_register_operand (p); | |
661 | else | |
662 | error (_("Unknown numeric token on expression `%s'."), | |
663 | p->saved_arg); | |
664 | } | |
665 | else if (const_prefix | |
666 | && strncmp (p->arg, const_prefix, const_prefix_len) == 0) | |
667 | { | |
668 | /* We are dealing with a numeric constant. */ | |
669 | long number; | |
670 | ||
671 | p->arg += const_prefix_len; | |
672 | number = strtol (p->arg, (char **) &p->arg, 10); | |
673 | ||
674 | write_exp_elt_opcode (OP_LONG); | |
675 | write_exp_elt_type (builtin_type (gdbarch)->builtin_long); | |
676 | write_exp_elt_longcst (number); | |
677 | write_exp_elt_opcode (OP_LONG); | |
678 | ||
679 | if (const_suffix) | |
680 | { | |
681 | if (strncmp (p->arg, const_suffix, const_suffix_len) == 0) | |
682 | p->arg += const_suffix_len; | |
683 | else | |
684 | error (_("Invalid constant suffix on expression `%s'."), | |
685 | p->saved_arg); | |
686 | } | |
687 | } | |
688 | else if ((reg_prefix | |
689 | && strncmp (p->arg, reg_prefix, reg_prefix_len) == 0) | |
690 | || (reg_ind_prefix | |
691 | && strncmp (p->arg, reg_ind_prefix, reg_ind_prefix_len) == 0)) | |
692 | stap_parse_register_operand (p); | |
693 | else | |
694 | error (_("Operator `%c' not recognized on expression `%s'."), | |
695 | *p->arg, p->saved_arg); | |
696 | } | |
697 | ||
698 | /* This function parses an argument conditionally, based on single or | |
699 | non-single operands. A non-single operand would be a parenthesized | |
700 | expression (e.g., `(2 + 1)'), and a single operand is anything that | |
701 | starts with `-', `~', `+' (i.e., unary operators), a digit, or | |
702 | something recognized by `gdbarch_stap_is_single_operand'. */ | |
703 | ||
704 | static void | |
705 | stap_parse_argument_conditionally (struct stap_parse_info *p) | |
706 | { | |
707 | if (*p->arg == '-' || *p->arg == '~' || *p->arg == '+' /* Unary. */ | |
708 | || isdigit (*p->arg) | |
709 | || gdbarch_stap_is_single_operand (p->gdbarch, p->arg)) | |
710 | stap_parse_single_operand (p); | |
711 | else if (*p->arg == '(') | |
712 | { | |
713 | /* We are dealing with a parenthesized operand. It means we | |
714 | have to parse it as it was a separate expression, without | |
715 | left-side or precedence. */ | |
716 | ++p->arg; | |
717 | p->arg = skip_spaces_const (p->arg); | |
718 | ++p->inside_paren_p; | |
719 | ||
720 | stap_parse_argument_1 (p, 0, STAP_OPERAND_PREC_NONE); | |
721 | ||
722 | --p->inside_paren_p; | |
723 | if (*p->arg != ')') | |
724 | error (_("Missign close-paren on expression `%s'."), | |
725 | p->saved_arg); | |
726 | ||
727 | ++p->arg; | |
728 | if (p->inside_paren_p) | |
729 | p->arg = skip_spaces_const (p->arg); | |
730 | } | |
731 | else | |
732 | error (_("Cannot parse expression `%s'."), p->saved_arg); | |
733 | } | |
734 | ||
735 | /* Helper function for `stap_parse_argument'. Please, see its comments to | |
736 | better understand what this function does. */ | |
737 | ||
738 | static void | |
739 | stap_parse_argument_1 (struct stap_parse_info *p, int has_lhs, | |
740 | enum stap_operand_prec prec) | |
741 | { | |
742 | /* This is an operator-precedence parser. | |
743 | ||
744 | We work with left- and right-sides of expressions, and | |
745 | parse them depending on the precedence of the operators | |
746 | we find. */ | |
747 | ||
748 | if (p->inside_paren_p) | |
749 | p->arg = skip_spaces_const (p->arg); | |
750 | ||
751 | if (!has_lhs) | |
752 | { | |
753 | /* We were called without a left-side, either because this is the | |
754 | first call, or because we were called to parse a parenthesized | |
755 | expression. It doesn't really matter; we have to parse the | |
756 | left-side in order to continue the process. */ | |
757 | stap_parse_argument_conditionally (p); | |
758 | } | |
759 | ||
760 | /* Start to parse the right-side, and to "join" left and right sides | |
761 | depending on the operation specified. | |
762 | ||
763 | This loop shall continue until we run out of characters in the input, | |
764 | or until we find a close-parenthesis, which means that we've reached | |
765 | the end of a sub-expression. */ | |
766 | while (p->arg && *p->arg && *p->arg != ')' && !isspace (*p->arg)) | |
767 | { | |
768 | const char *tmp_exp_buf; | |
769 | enum exp_opcode opcode; | |
770 | enum stap_operand_prec cur_prec; | |
771 | ||
fcf57f19 | 772 | if (!stap_is_operator (p->arg)) |
55aa24fb SDJ |
773 | error (_("Invalid operator `%c' on expression `%s'."), *p->arg, |
774 | p->saved_arg); | |
775 | ||
776 | /* We have to save the current value of the expression buffer because | |
777 | the `stap_get_opcode' modifies it in order to get the current | |
778 | operator. If this operator's precedence is lower than PREC, we | |
779 | should return and not advance the expression buffer pointer. */ | |
780 | tmp_exp_buf = p->arg; | |
fcf57f19 | 781 | opcode = stap_get_opcode (&tmp_exp_buf); |
55aa24fb SDJ |
782 | |
783 | cur_prec = stap_get_operator_prec (opcode); | |
784 | if (cur_prec < prec) | |
785 | { | |
786 | /* If the precedence of the operator that we are seeing now is | |
787 | lower than the precedence of the first operator seen before | |
788 | this parsing process began, it means we should stop parsing | |
789 | and return. */ | |
790 | break; | |
791 | } | |
792 | ||
793 | p->arg = tmp_exp_buf; | |
794 | if (p->inside_paren_p) | |
795 | p->arg = skip_spaces_const (p->arg); | |
796 | ||
797 | /* Parse the right-side of the expression. */ | |
798 | stap_parse_argument_conditionally (p); | |
799 | ||
800 | /* While we still have operators, try to parse another | |
801 | right-side, but using the current right-side as a left-side. */ | |
fcf57f19 | 802 | while (*p->arg && stap_is_operator (p->arg)) |
55aa24fb SDJ |
803 | { |
804 | enum exp_opcode lookahead_opcode; | |
805 | enum stap_operand_prec lookahead_prec; | |
806 | ||
807 | /* Saving the current expression buffer position. The explanation | |
808 | is the same as above. */ | |
809 | tmp_exp_buf = p->arg; | |
fcf57f19 | 810 | lookahead_opcode = stap_get_opcode (&tmp_exp_buf); |
55aa24fb SDJ |
811 | lookahead_prec = stap_get_operator_prec (lookahead_opcode); |
812 | ||
813 | if (lookahead_prec <= prec) | |
814 | { | |
815 | /* If we are dealing with an operator whose precedence is lower | |
816 | than the first one, just abandon the attempt. */ | |
817 | break; | |
818 | } | |
819 | ||
820 | /* Parse the right-side of the expression, but since we already | |
821 | have a left-side at this point, set `has_lhs' to 1. */ | |
822 | stap_parse_argument_1 (p, 1, lookahead_prec); | |
823 | } | |
824 | ||
825 | write_exp_elt_opcode (opcode); | |
826 | } | |
827 | } | |
828 | ||
829 | /* Parse a probe's argument. | |
830 | ||
831 | Assuming that: | |
832 | ||
833 | LP = literal integer prefix | |
834 | LS = literal integer suffix | |
835 | ||
836 | RP = register prefix | |
837 | RS = register suffix | |
838 | ||
839 | RIP = register indirection prefix | |
840 | RIS = register indirection suffix | |
841 | ||
842 | This routine assumes that arguments' tokens are of the form: | |
843 | ||
844 | - [LP] NUMBER [LS] | |
845 | - [RP] REGISTER [RS] | |
846 | - [RIP] [RP] REGISTER [RS] [RIS] | |
847 | - If we find a number without LP, we try to parse it as a literal integer | |
848 | constant (if LP == NULL), or as a register displacement. | |
849 | - We count parenthesis, and only skip whitespaces if we are inside them. | |
850 | - If we find an operator, we skip it. | |
851 | ||
852 | This function can also call a special function that will try to match | |
853 | unknown tokens. It will return 1 if the argument has been parsed | |
854 | successfully, or zero otherwise. */ | |
855 | ||
856 | static struct expression * | |
857 | stap_parse_argument (const char **arg, struct type *atype, | |
858 | struct gdbarch *gdbarch) | |
859 | { | |
860 | struct stap_parse_info p; | |
55aa24fb SDJ |
861 | struct cleanup *back_to; |
862 | ||
863 | /* We need to initialize the expression buffer, in order to begin | |
864 | our parsing efforts. The language here does not matter, since we | |
865 | are using our own parser. */ | |
866 | initialize_expout (10, current_language, gdbarch); | |
867 | back_to = make_cleanup (free_current_contents, &expout); | |
868 | ||
869 | p.saved_arg = *arg; | |
870 | p.arg = *arg; | |
871 | p.arg_type = atype; | |
872 | p.gdbarch = gdbarch; | |
873 | p.inside_paren_p = 0; | |
874 | ||
875 | stap_parse_argument_1 (&p, 0, STAP_OPERAND_PREC_NONE); | |
876 | ||
877 | discard_cleanups (back_to); | |
878 | ||
879 | gdb_assert (p.inside_paren_p == 0); | |
880 | ||
881 | /* Casting the final expression to the appropriate type. */ | |
882 | write_exp_elt_opcode (UNOP_CAST); | |
883 | write_exp_elt_type (atype); | |
884 | write_exp_elt_opcode (UNOP_CAST); | |
885 | ||
886 | reallocate_expout (); | |
887 | ||
888 | p.arg = skip_spaces_const (p.arg); | |
889 | *arg = p.arg; | |
890 | ||
891 | return expout; | |
892 | } | |
893 | ||
894 | /* Function which parses an argument string from PROBE, correctly splitting | |
895 | the arguments and storing their information in properly ways. | |
896 | ||
897 | Consider the following argument string (x86 syntax): | |
898 | ||
899 | `4@%eax 4@$10' | |
900 | ||
901 | We have two arguments, `%eax' and `$10', both with 32-bit unsigned bitness. | |
902 | This function basically handles them, properly filling some structures with | |
903 | this information. */ | |
904 | ||
905 | static void | |
906 | stap_parse_probe_arguments (struct stap_probe *probe, struct objfile *objfile) | |
907 | { | |
908 | const char *cur; | |
909 | struct gdbarch *gdbarch = get_objfile_arch (objfile); | |
910 | ||
911 | gdb_assert (!probe->args_parsed); | |
912 | cur = probe->args_u.text; | |
913 | probe->args_parsed = 1; | |
914 | probe->args_u.vec = NULL; | |
915 | ||
916 | if (!cur || !*cur || *cur == ':') | |
917 | return; | |
918 | ||
919 | while (*cur) | |
920 | { | |
921 | struct stap_probe_arg arg; | |
922 | enum stap_arg_bitness b; | |
923 | int got_minus = 0; | |
924 | struct expression *expr; | |
925 | ||
926 | memset (&arg, 0, sizeof (arg)); | |
927 | ||
928 | /* We expect to find something like: | |
929 | ||
930 | N@OP | |
931 | ||
932 | Where `N' can be [+,-][4,8]. This is not mandatory, so | |
933 | we check it here. If we don't find it, go to the next | |
934 | state. */ | |
935 | if ((*cur == '-' && cur[1] && cur[2] != '@') | |
936 | && cur[1] != '@') | |
937 | arg.bitness = STAP_ARG_BITNESS_UNDEFINED; | |
938 | else | |
939 | { | |
940 | if (*cur == '-') | |
941 | { | |
942 | /* Discard the `-'. */ | |
943 | ++cur; | |
944 | got_minus = 1; | |
945 | } | |
946 | ||
947 | if (*cur == '4') | |
948 | b = (got_minus ? STAP_ARG_BITNESS_32BIT_SIGNED | |
949 | : STAP_ARG_BITNESS_32BIT_UNSIGNED); | |
950 | else if (*cur == '8') | |
951 | b = (got_minus ? STAP_ARG_BITNESS_64BIT_SIGNED | |
952 | : STAP_ARG_BITNESS_64BIT_UNSIGNED); | |
953 | else | |
954 | { | |
955 | /* We have an error, because we don't expect anything | |
956 | except 4 and 8. */ | |
957 | complaint (&symfile_complaints, | |
958 | _("unrecognized bitness `%c' for probe `%s'"), | |
959 | *cur, probe->p.name); | |
960 | return; | |
961 | } | |
962 | ||
963 | arg.bitness = b; | |
964 | arg.atype = stap_get_expected_argument_type (gdbarch, b); | |
965 | ||
966 | /* Discard the number and the `@' sign. */ | |
967 | cur += 2; | |
968 | } | |
969 | ||
970 | expr = stap_parse_argument (&cur, arg.atype, gdbarch); | |
971 | ||
972 | if (stap_expression_debug) | |
973 | dump_raw_expression (expr, gdb_stdlog, | |
974 | "before conversion to prefix form"); | |
975 | ||
976 | prefixify_expression (expr); | |
977 | ||
978 | if (stap_expression_debug) | |
979 | dump_prefix_expression (expr, gdb_stdlog); | |
980 | ||
981 | arg.aexpr = expr; | |
982 | ||
983 | /* Start it over again. */ | |
984 | cur = skip_spaces_const (cur); | |
985 | ||
986 | VEC_safe_push (stap_probe_arg_s, probe->args_u.vec, &arg); | |
987 | } | |
988 | } | |
989 | ||
990 | /* Given PROBE, returns the number of arguments present in that probe's | |
991 | argument string. */ | |
992 | ||
993 | static unsigned | |
994 | stap_get_probe_argument_count (struct probe *probe_generic, | |
995 | struct objfile *objfile) | |
996 | { | |
997 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
998 | ||
999 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1000 | ||
1001 | if (!probe->args_parsed) | |
1002 | stap_parse_probe_arguments (probe, objfile); | |
1003 | ||
1004 | gdb_assert (probe->args_parsed); | |
1005 | return VEC_length (stap_probe_arg_s, probe->args_u.vec); | |
1006 | } | |
1007 | ||
1008 | /* Return 1 if OP is a valid operator inside a probe argument, or zero | |
1009 | otherwise. */ | |
1010 | ||
1011 | static int | |
fcf57f19 | 1012 | stap_is_operator (const char *op) |
55aa24fb | 1013 | { |
fcf57f19 SDJ |
1014 | int ret = 1; |
1015 | ||
1016 | switch (*op) | |
1017 | { | |
1018 | case '*': | |
1019 | case '/': | |
1020 | case '%': | |
1021 | case '^': | |
1022 | case '!': | |
1023 | case '+': | |
1024 | case '-': | |
1025 | case '<': | |
1026 | case '>': | |
1027 | case '|': | |
1028 | case '&': | |
1029 | break; | |
1030 | ||
1031 | case '=': | |
1032 | if (op[1] != '=') | |
1033 | ret = 0; | |
1034 | break; | |
1035 | ||
1036 | default: | |
1037 | /* We didn't find any operator. */ | |
1038 | ret = 0; | |
1039 | } | |
1040 | ||
1041 | return ret; | |
55aa24fb SDJ |
1042 | } |
1043 | ||
1044 | static struct stap_probe_arg * | |
1045 | stap_get_arg (struct stap_probe *probe, struct objfile *objfile, unsigned n) | |
1046 | { | |
1047 | if (!probe->args_parsed) | |
1048 | stap_parse_probe_arguments (probe, objfile); | |
1049 | ||
1050 | return VEC_index (stap_probe_arg_s, probe->args_u.vec, n); | |
1051 | } | |
1052 | ||
1053 | /* Evaluate the probe's argument N (indexed from 0), returning a value | |
1054 | corresponding to it. Assertion is thrown if N does not exist. */ | |
1055 | ||
1056 | static struct value * | |
1057 | stap_evaluate_probe_argument (struct probe *probe_generic, | |
1058 | struct objfile *objfile, unsigned n) | |
1059 | { | |
1060 | struct stap_probe *stap_probe = (struct stap_probe *) probe_generic; | |
1061 | struct stap_probe_arg *arg; | |
1062 | int pos = 0; | |
1063 | ||
1064 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1065 | ||
1066 | arg = stap_get_arg (stap_probe, objfile, n); | |
1067 | return evaluate_subexp_standard (arg->atype, arg->aexpr, &pos, EVAL_NORMAL); | |
1068 | } | |
1069 | ||
1070 | /* Compile the probe's argument N (indexed from 0) to agent expression. | |
1071 | Assertion is thrown if N does not exist. */ | |
1072 | ||
1073 | static void | |
1074 | stap_compile_to_ax (struct probe *probe_generic, struct objfile *objfile, | |
1075 | struct agent_expr *expr, struct axs_value *value, | |
1076 | unsigned n) | |
1077 | { | |
1078 | struct stap_probe *stap_probe = (struct stap_probe *) probe_generic; | |
1079 | struct stap_probe_arg *arg; | |
1080 | union exp_element *pc; | |
1081 | ||
1082 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1083 | ||
1084 | arg = stap_get_arg (stap_probe, objfile, n); | |
1085 | ||
1086 | pc = arg->aexpr->elts; | |
1087 | gen_expr (arg->aexpr, &pc, expr, value); | |
1088 | ||
1089 | require_rvalue (expr, value); | |
1090 | value->type = arg->atype; | |
1091 | } | |
1092 | ||
1093 | /* Destroy (free) the data related to PROBE. PROBE memory itself is not feed | |
1094 | as it is allocated from OBJFILE_OBSTACK. */ | |
1095 | ||
1096 | static void | |
1097 | stap_probe_destroy (struct probe *probe_generic) | |
1098 | { | |
1099 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
1100 | ||
1101 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1102 | ||
1103 | if (probe->args_parsed) | |
1104 | { | |
1105 | struct stap_probe_arg *arg; | |
1106 | int ix; | |
1107 | ||
1108 | for (ix = 0; VEC_iterate (stap_probe_arg_s, probe->args_u.vec, ix, arg); | |
1109 | ++ix) | |
1110 | xfree (arg->aexpr); | |
1111 | VEC_free (stap_probe_arg_s, probe->args_u.vec); | |
1112 | } | |
1113 | } | |
1114 | ||
1115 | \f | |
1116 | ||
1117 | /* This is called to compute the value of one of the $_probe_arg* | |
1118 | convenience variables. */ | |
1119 | ||
1120 | static struct value * | |
1121 | compute_probe_arg (struct gdbarch *arch, struct internalvar *ivar, | |
1122 | void *data) | |
1123 | { | |
1124 | struct frame_info *frame = get_selected_frame (_("No frame selected")); | |
1125 | CORE_ADDR pc = get_frame_pc (frame); | |
1126 | int sel = (int) (uintptr_t) data; | |
1127 | struct objfile *objfile; | |
1128 | struct probe *pc_probe; | |
1129 | unsigned n_args; | |
1130 | ||
1131 | /* SEL == -1 means "_probe_argc". */ | |
1132 | gdb_assert (sel >= -1); | |
1133 | ||
1134 | pc_probe = find_probe_by_pc (pc, &objfile); | |
1135 | if (pc_probe == NULL) | |
1136 | error (_("No SystemTap probe at PC %s"), core_addr_to_string (pc)); | |
1137 | ||
1138 | n_args | |
1139 | = objfile->sf->sym_probe_fns->sym_get_probe_argument_count (objfile, | |
1140 | pc_probe); | |
1141 | if (sel == -1) | |
1142 | return value_from_longest (builtin_type (arch)->builtin_int, n_args); | |
1143 | ||
1144 | if (sel >= n_args) | |
1145 | error (_("Invalid probe argument %d -- probe has %u arguments available"), | |
1146 | sel, n_args); | |
1147 | ||
1148 | return objfile->sf->sym_probe_fns->sym_evaluate_probe_argument (objfile, | |
1149 | pc_probe, | |
1150 | sel); | |
1151 | } | |
1152 | ||
1153 | /* This is called to compile one of the $_probe_arg* convenience | |
1154 | variables into an agent expression. */ | |
1155 | ||
1156 | static void | |
1157 | compile_probe_arg (struct internalvar *ivar, struct agent_expr *expr, | |
1158 | struct axs_value *value, void *data) | |
1159 | { | |
1160 | CORE_ADDR pc = expr->scope; | |
1161 | int sel = (int) (uintptr_t) data; | |
1162 | struct objfile *objfile; | |
1163 | struct probe *pc_probe; | |
1164 | int n_probes; | |
1165 | ||
1166 | /* SEL == -1 means "_probe_argc". */ | |
1167 | gdb_assert (sel >= -1); | |
1168 | ||
1169 | pc_probe = find_probe_by_pc (pc, &objfile); | |
1170 | if (pc_probe == NULL) | |
1171 | error (_("No SystemTap probe at PC %s"), core_addr_to_string (pc)); | |
1172 | ||
1173 | n_probes | |
1174 | = objfile->sf->sym_probe_fns->sym_get_probe_argument_count (objfile, | |
1175 | pc_probe); | |
1176 | if (sel == -1) | |
1177 | { | |
1178 | value->kind = axs_rvalue; | |
1179 | value->type = builtin_type (expr->gdbarch)->builtin_int; | |
1180 | ax_const_l (expr, n_probes); | |
1181 | return; | |
1182 | } | |
1183 | ||
1184 | gdb_assert (sel >= 0); | |
1185 | if (sel >= n_probes) | |
1186 | error (_("Invalid probe argument %d -- probe has %d arguments available"), | |
1187 | sel, n_probes); | |
1188 | ||
1189 | objfile->sf->sym_probe_fns->sym_compile_to_ax (objfile, pc_probe, | |
1190 | expr, value, sel); | |
1191 | } | |
1192 | ||
1193 | \f | |
1194 | ||
1195 | /* Set or clear a SystemTap semaphore. ADDRESS is the semaphore's | |
1196 | address. SET is zero if the semaphore should be cleared, or one | |
1197 | if it should be set. This is a helper function for `stap_semaphore_down' | |
1198 | and `stap_semaphore_up'. */ | |
1199 | ||
1200 | static void | |
1201 | stap_modify_semaphore (CORE_ADDR address, int set, struct gdbarch *gdbarch) | |
1202 | { | |
1203 | gdb_byte bytes[sizeof (LONGEST)]; | |
1204 | /* The ABI specifies "unsigned short". */ | |
1205 | struct type *type = builtin_type (gdbarch)->builtin_unsigned_short; | |
1206 | ULONGEST value; | |
1207 | ||
1208 | if (address == 0) | |
1209 | return; | |
1210 | ||
1211 | /* Swallow errors. */ | |
1212 | if (target_read_memory (address, bytes, TYPE_LENGTH (type)) != 0) | |
1213 | { | |
1214 | warning (_("Could not read the value of a SystemTap semaphore.")); | |
1215 | return; | |
1216 | } | |
1217 | ||
1218 | value = extract_unsigned_integer (bytes, TYPE_LENGTH (type), | |
1219 | gdbarch_byte_order (gdbarch)); | |
1220 | /* Note that we explicitly don't worry about overflow or | |
1221 | underflow. */ | |
1222 | if (set) | |
1223 | ++value; | |
1224 | else | |
1225 | --value; | |
1226 | ||
1227 | store_unsigned_integer (bytes, TYPE_LENGTH (type), | |
1228 | gdbarch_byte_order (gdbarch), value); | |
1229 | ||
1230 | if (target_write_memory (address, bytes, TYPE_LENGTH (type)) != 0) | |
1231 | warning (_("Could not write the value of a SystemTap semaphore.")); | |
1232 | } | |
1233 | ||
1234 | /* Set a SystemTap semaphore. SEM is the semaphore's address. Semaphores | |
1235 | act as reference counters, so calls to this function must be paired with | |
1236 | calls to `stap_semaphore_down'. | |
1237 | ||
1238 | This function and `stap_semaphore_down' race with another tool changing | |
1239 | the probes, but that is too rare to care. */ | |
1240 | ||
1241 | static void | |
1242 | stap_set_semaphore (struct probe *probe_generic, struct gdbarch *gdbarch) | |
1243 | { | |
1244 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
1245 | ||
1246 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1247 | ||
1248 | stap_modify_semaphore (probe->sem_addr, 1, gdbarch); | |
1249 | } | |
1250 | ||
1251 | /* Clear a SystemTap semaphore. SEM is the semaphore's address. */ | |
1252 | ||
1253 | static void | |
1254 | stap_clear_semaphore (struct probe *probe_generic, struct gdbarch *gdbarch) | |
1255 | { | |
1256 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
1257 | ||
1258 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1259 | ||
1260 | stap_modify_semaphore (probe->sem_addr, 0, gdbarch); | |
1261 | } | |
1262 | ||
1263 | /* Implementation of `$_probe_arg*' set of variables. */ | |
1264 | ||
1265 | static const struct internalvar_funcs probe_funcs = | |
1266 | { | |
1267 | compute_probe_arg, | |
1268 | compile_probe_arg, | |
1269 | NULL | |
1270 | }; | |
1271 | ||
1272 | /* Helper function that parses the information contained in a | |
1273 | SystemTap's probe. Basically, the information consists in: | |
1274 | ||
1275 | - Probe's PC address; | |
1276 | - Link-time section address of `.stapsdt.base' section; | |
1277 | - Link-time address of the semaphore variable, or ZERO if the | |
1278 | probe doesn't have an associated semaphore; | |
1279 | - Probe's provider name; | |
1280 | - Probe's name; | |
1281 | - Probe's argument format | |
1282 | ||
1283 | This function returns 1 if the handling was successful, and zero | |
1284 | otherwise. */ | |
1285 | ||
1286 | static void | |
1287 | handle_stap_probe (struct objfile *objfile, struct sdt_note *el, | |
1288 | VEC (probe_p) **probesp, CORE_ADDR base) | |
1289 | { | |
1290 | bfd *abfd = objfile->obfd; | |
1291 | int size = bfd_get_arch_size (abfd) / 8; | |
1292 | struct gdbarch *gdbarch = get_objfile_arch (objfile); | |
55aa24fb SDJ |
1293 | struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
1294 | CORE_ADDR base_ref; | |
1295 | const char *probe_args = NULL; | |
1296 | struct stap_probe *ret; | |
1297 | ||
1298 | ret = obstack_alloc (&objfile->objfile_obstack, sizeof (*ret)); | |
1299 | ret->p.pops = &stap_probe_ops; | |
1300 | ||
1301 | /* Provider and the name of the probe. */ | |
1302 | ret->p.provider = &el->data[3 * size]; | |
1303 | ret->p.name = memchr (ret->p.provider, '\0', | |
1304 | (char *) el->data + el->size - ret->p.provider); | |
1305 | /* Making sure there is a name. */ | |
1306 | if (!ret->p.name) | |
1307 | { | |
1308 | complaint (&symfile_complaints, _("corrupt probe name when " | |
1309 | "reading `%s'"), objfile->name); | |
1310 | ||
1311 | /* There is no way to use a probe without a name or a provider, so | |
1312 | returning zero here makes sense. */ | |
1313 | return; | |
1314 | } | |
1315 | else | |
1316 | ++ret->p.name; | |
1317 | ||
1318 | /* Retrieving the probe's address. */ | |
1319 | ret->p.address = extract_typed_address (&el->data[0], ptr_type); | |
1320 | ||
1321 | /* Link-time sh_addr of `.stapsdt.base' section. */ | |
1322 | base_ref = extract_typed_address (&el->data[size], ptr_type); | |
1323 | ||
1324 | /* Semaphore address. */ | |
1325 | ret->sem_addr = extract_typed_address (&el->data[2 * size], ptr_type); | |
1326 | ||
1327 | ret->p.address += (ANOFFSET (objfile->section_offsets, | |
1328 | SECT_OFF_TEXT (objfile)) | |
1329 | + base - base_ref); | |
1330 | if (ret->sem_addr) | |
1331 | ret->sem_addr += (ANOFFSET (objfile->section_offsets, | |
1332 | SECT_OFF_DATA (objfile)) | |
1333 | + base - base_ref); | |
1334 | ||
1335 | /* Arguments. We can only extract the argument format if there is a valid | |
1336 | name for this probe. */ | |
1337 | probe_args = memchr (ret->p.name, '\0', | |
1338 | (char *) el->data + el->size - ret->p.name); | |
1339 | ||
1340 | if (probe_args != NULL) | |
1341 | ++probe_args; | |
1342 | ||
1343 | if (probe_args == NULL || (memchr (probe_args, '\0', | |
1344 | (char *) el->data + el->size - ret->p.name) | |
1345 | != el->data + el->size - 1)) | |
1346 | { | |
1347 | complaint (&symfile_complaints, _("corrupt probe argument when " | |
1348 | "reading `%s'"), objfile->name); | |
1349 | /* If the argument string is NULL, it means some problem happened with | |
1350 | it. So we return 0. */ | |
1351 | return; | |
1352 | } | |
1353 | ||
1354 | ret->args_parsed = 0; | |
1355 | ret->args_u.text = (void *) probe_args; | |
1356 | ||
1357 | /* Successfully created probe. */ | |
1358 | VEC_safe_push (probe_p, *probesp, (struct probe *) ret); | |
1359 | } | |
1360 | ||
1361 | /* Helper function which tries to find the base address of the SystemTap | |
1362 | base section named STAP_BASE_SECTION_NAME. */ | |
1363 | ||
1364 | static void | |
1365 | get_stap_base_address_1 (bfd *abfd, asection *sect, void *obj) | |
1366 | { | |
1367 | asection **ret = obj; | |
1368 | ||
1369 | if ((sect->flags & (SEC_DATA | SEC_ALLOC | SEC_HAS_CONTENTS)) | |
1370 | && sect->name && !strcmp (sect->name, STAP_BASE_SECTION_NAME)) | |
1371 | *ret = sect; | |
1372 | } | |
1373 | ||
1374 | /* Helper function which iterates over every section in the BFD file, | |
1375 | trying to find the base address of the SystemTap base section. | |
1376 | Returns 1 if found (setting BASE to the proper value), zero otherwise. */ | |
1377 | ||
1378 | static int | |
1379 | get_stap_base_address (bfd *obfd, bfd_vma *base) | |
1380 | { | |
1381 | asection *ret = NULL; | |
1382 | ||
1383 | bfd_map_over_sections (obfd, get_stap_base_address_1, (void *) &ret); | |
1384 | ||
1385 | if (!ret) | |
1386 | { | |
1387 | complaint (&symfile_complaints, _("could not obtain base address for " | |
1388 | "SystemTap section on objfile `%s'."), | |
1389 | obfd->filename); | |
1390 | return 0; | |
1391 | } | |
1392 | ||
1393 | if (base) | |
1394 | *base = ret->vma; | |
1395 | ||
1396 | return 1; | |
1397 | } | |
1398 | ||
1399 | /* Helper function for `elf_get_probes', which gathers information about all | |
1400 | SystemTap probes from OBJFILE. */ | |
1401 | ||
1402 | static void | |
1403 | stap_get_probes (VEC (probe_p) **probesp, struct objfile *objfile) | |
1404 | { | |
1405 | /* If we are here, then this is the first time we are parsing the | |
1406 | SystemTap probe's information. We basically have to count how many | |
1407 | probes the objfile has, and then fill in the necessary information | |
1408 | for each one. */ | |
1409 | bfd *obfd = objfile->obfd; | |
1410 | bfd_vma base; | |
1411 | struct sdt_note *iter; | |
1412 | unsigned save_probesp_len = VEC_length (probe_p, *probesp); | |
1413 | ||
d7333987 SDJ |
1414 | if (objfile->separate_debug_objfile_backlink != NULL) |
1415 | { | |
1416 | /* This is a .debug file, not the objfile itself. */ | |
1417 | return; | |
1418 | } | |
1419 | ||
55aa24fb SDJ |
1420 | if (!elf_tdata (obfd)->sdt_note_head) |
1421 | { | |
1422 | /* There isn't any probe here. */ | |
1423 | return; | |
1424 | } | |
1425 | ||
1426 | if (!get_stap_base_address (obfd, &base)) | |
1427 | { | |
1428 | /* There was an error finding the base address for the section. | |
1429 | Just return NULL. */ | |
1430 | return; | |
1431 | } | |
1432 | ||
1433 | /* Parsing each probe's information. */ | |
1434 | for (iter = elf_tdata (obfd)->sdt_note_head; iter; iter = iter->next) | |
1435 | { | |
1436 | /* We first have to handle all the information about the | |
1437 | probe which is present in the section. */ | |
1438 | handle_stap_probe (objfile, iter, probesp, base); | |
1439 | } | |
1440 | ||
1441 | if (save_probesp_len == VEC_length (probe_p, *probesp)) | |
1442 | { | |
1443 | /* If we are here, it means we have failed to parse every known | |
1444 | probe. */ | |
1445 | complaint (&symfile_complaints, _("could not parse SystemTap probe(s) " | |
1446 | "from inferior")); | |
1447 | return; | |
1448 | } | |
1449 | } | |
1450 | ||
1451 | static void | |
1452 | stap_relocate (struct probe *probe_generic, CORE_ADDR delta) | |
1453 | { | |
1454 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
1455 | ||
1456 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1457 | ||
1458 | probe->p.address += delta; | |
1459 | if (probe->sem_addr) | |
1460 | probe->sem_addr += delta; | |
1461 | } | |
1462 | ||
1463 | static int | |
1464 | stap_probe_is_linespec (const char **linespecp) | |
1465 | { | |
1466 | static const char *const keywords[] = { "-pstap", "-probe-stap", NULL }; | |
1467 | ||
1468 | return probe_is_linespec_by_keyword (linespecp, keywords); | |
1469 | } | |
1470 | ||
1471 | static void | |
1472 | stap_gen_info_probes_table_header (VEC (info_probe_column_s) **heads) | |
1473 | { | |
1474 | info_probe_column_s stap_probe_column; | |
1475 | ||
1476 | stap_probe_column.field_name = "semaphore"; | |
1477 | stap_probe_column.print_name = _("Semaphore"); | |
1478 | ||
1479 | VEC_safe_push (info_probe_column_s, *heads, &stap_probe_column); | |
1480 | } | |
1481 | ||
1482 | static void | |
1483 | stap_gen_info_probes_table_values (struct probe *probe_generic, | |
1484 | struct objfile *objfile, | |
1485 | VEC (const_char_ptr) **ret) | |
1486 | { | |
1487 | struct stap_probe *probe = (struct stap_probe *) probe_generic; | |
1488 | struct gdbarch *gdbarch = get_objfile_arch (objfile); | |
1489 | const char *val = NULL; | |
1490 | ||
1491 | gdb_assert (probe_generic->pops == &stap_probe_ops); | |
1492 | ||
1493 | if (probe->sem_addr) | |
1494 | val = print_core_address (gdbarch, probe->sem_addr); | |
1495 | ||
1496 | VEC_safe_push (const_char_ptr, *ret, val); | |
1497 | } | |
1498 | ||
1499 | /* SystemTap probe_ops. */ | |
1500 | ||
1501 | static const struct probe_ops stap_probe_ops = | |
1502 | { | |
1503 | stap_probe_is_linespec, | |
1504 | stap_get_probes, | |
1505 | stap_relocate, | |
1506 | stap_get_probe_argument_count, | |
1507 | stap_evaluate_probe_argument, | |
1508 | stap_compile_to_ax, | |
1509 | stap_set_semaphore, | |
1510 | stap_clear_semaphore, | |
1511 | stap_probe_destroy, | |
1512 | stap_gen_info_probes_table_header, | |
1513 | stap_gen_info_probes_table_values, | |
1514 | }; | |
1515 | ||
1516 | /* Implementation of the `info probes stap' command. */ | |
1517 | ||
1518 | static void | |
1519 | info_probes_stap_command (char *arg, int from_tty) | |
1520 | { | |
1521 | info_probes_for_ops (arg, from_tty, &stap_probe_ops); | |
1522 | } | |
1523 | ||
1524 | void _initialize_stap_probe (void); | |
1525 | ||
1526 | void | |
1527 | _initialize_stap_probe (void) | |
1528 | { | |
1529 | VEC_safe_push (probe_ops_cp, all_probe_ops, &stap_probe_ops); | |
1530 | ||
1531 | add_setshow_zinteger_cmd ("stap-expression", class_maintenance, | |
1532 | &stap_expression_debug, | |
1533 | _("Set SystemTap expression debugging."), | |
1534 | _("Show SystemTap expression debugging."), | |
1535 | _("When non-zero, the internal representation " | |
1536 | "of SystemTap expressions will be printed."), | |
1537 | NULL, | |
1538 | show_stapexpressiondebug, | |
1539 | &setdebuglist, &showdebuglist); | |
1540 | ||
1541 | create_internalvar_type_lazy ("_probe_argc", &probe_funcs, | |
1542 | (void *) (uintptr_t) -1); | |
1543 | create_internalvar_type_lazy ("_probe_arg0", &probe_funcs, | |
1544 | (void *) (uintptr_t) 0); | |
1545 | create_internalvar_type_lazy ("_probe_arg1", &probe_funcs, | |
1546 | (void *) (uintptr_t) 1); | |
1547 | create_internalvar_type_lazy ("_probe_arg2", &probe_funcs, | |
1548 | (void *) (uintptr_t) 2); | |
1549 | create_internalvar_type_lazy ("_probe_arg3", &probe_funcs, | |
1550 | (void *) (uintptr_t) 3); | |
1551 | create_internalvar_type_lazy ("_probe_arg4", &probe_funcs, | |
1552 | (void *) (uintptr_t) 4); | |
1553 | create_internalvar_type_lazy ("_probe_arg5", &probe_funcs, | |
1554 | (void *) (uintptr_t) 5); | |
1555 | create_internalvar_type_lazy ("_probe_arg6", &probe_funcs, | |
1556 | (void *) (uintptr_t) 6); | |
1557 | create_internalvar_type_lazy ("_probe_arg7", &probe_funcs, | |
1558 | (void *) (uintptr_t) 7); | |
1559 | create_internalvar_type_lazy ("_probe_arg8", &probe_funcs, | |
1560 | (void *) (uintptr_t) 8); | |
1561 | create_internalvar_type_lazy ("_probe_arg9", &probe_funcs, | |
1562 | (void *) (uintptr_t) 9); | |
1563 | create_internalvar_type_lazy ("_probe_arg10", &probe_funcs, | |
1564 | (void *) (uintptr_t) 10); | |
1565 | create_internalvar_type_lazy ("_probe_arg11", &probe_funcs, | |
1566 | (void *) (uintptr_t) 11); | |
1567 | ||
1568 | add_cmd ("stap", class_info, info_probes_stap_command, | |
1569 | _("\ | |
1570 | Show information about SystemTap static probes.\n\ | |
1571 | Usage: info probes stap [PROVIDER [NAME [OBJECT]]]\n\ | |
1572 | Each argument is a regular expression, used to select probes.\n\ | |
1573 | PROVIDER matches probe provider names.\n\ | |
1574 | NAME matches the probe names.\n\ | |
1575 | OBJECT matches the executable or shared library name."), | |
1576 | info_probes_cmdlist_get ()); | |
1577 | ||
1578 | } |