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This patch adds the above-mentioned commands to the generic probe abstraction implemented in probe.[ch]. The effects associated to enabling or disabling a probe depend on the type of probe being handled, and is triggered by invoking two back-end hooks in `probe_ops'. In case some particular probe type does not support the notion of enabling and/or disabling, the corresponding fields on `probe_ops' can be initialized to NULL. This is the case of SystemTap probes. gdb/ChangeLog: 2015-02-17 Jose E. Marchesi <jose.marchesi@oracle.com> * stap-probe.c (stap_probe_ops): Add NULLs in the static stap_probe_ops for `enable_probe' and `disable_probe'. * probe.c (enable_probes_command): New function. (disable_probes_command): Likewise. (_initialize_probe): Define the cli commands `enable probe' and `disable probe'. (parse_probe_linespec): New function. (info_probes_for_ops): Use parse_probe_linespec. * probe.h (probe_ops): New hooks `enable_probe' and `disable_probe'. gdb/doc/ChangeLog: 2015-02-17 Jose E. Marchesi <jose.marchesi@oracle.com> * gdb.texinfo (Static Probe Points): Cover the `enable probe' and `disable probe' commands.
1727 lines
47 KiB
C
1727 lines
47 KiB
C
/* SystemTap probe support for GDB.
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Copyright (C) 2012-2015 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "stap-probe.h"
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#include "probe.h"
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#include "vec.h"
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#include "ui-out.h"
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#include "objfiles.h"
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#include "arch-utils.h"
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#include "command.h"
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#include "gdbcmd.h"
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#include "filenames.h"
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#include "value.h"
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#include "ax.h"
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#include "ax-gdb.h"
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#include "complaints.h"
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#include "cli/cli-utils.h"
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#include "linespec.h"
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#include "user-regs.h"
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#include "parser-defs.h"
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#include "language.h"
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#include "elf-bfd.h"
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#include <ctype.h>
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/* The name of the SystemTap section where we will find information about
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the probes. */
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#define STAP_BASE_SECTION_NAME ".stapsdt.base"
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/* Forward declaration. */
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extern const struct probe_ops stap_probe_ops;
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/* Should we display debug information for the probe's argument expression
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parsing? */
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static unsigned int stap_expression_debug = 0;
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/* The various possibilities of bitness defined for a probe's argument.
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The relationship is:
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- STAP_ARG_BITNESS_UNDEFINED: The user hasn't specified the bitness.
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- STAP_ARG_BITNESS_8BIT_UNSIGNED: argument string starts with `1@'.
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- STAP_ARG_BITNESS_8BIT_SIGNED: argument string starts with `-1@'.
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- STAP_ARG_BITNESS_16BIT_UNSIGNED: argument string starts with `2@'.
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- STAP_ARG_BITNESS_16BIT_SIGNED: argument string starts with `-2@'.
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- STAP_ARG_BITNESS_32BIT_UNSIGNED: argument string starts with `4@'.
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- STAP_ARG_BITNESS_32BIT_SIGNED: argument string starts with `-4@'.
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- STAP_ARG_BITNESS_64BIT_UNSIGNED: argument string starts with `8@'.
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- STAP_ARG_BITNESS_64BIT_SIGNED: argument string starts with `-8@'. */
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enum stap_arg_bitness
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{
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STAP_ARG_BITNESS_UNDEFINED,
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STAP_ARG_BITNESS_8BIT_UNSIGNED,
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STAP_ARG_BITNESS_8BIT_SIGNED,
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STAP_ARG_BITNESS_16BIT_UNSIGNED,
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STAP_ARG_BITNESS_16BIT_SIGNED,
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STAP_ARG_BITNESS_32BIT_UNSIGNED,
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STAP_ARG_BITNESS_32BIT_SIGNED,
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STAP_ARG_BITNESS_64BIT_UNSIGNED,
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STAP_ARG_BITNESS_64BIT_SIGNED,
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};
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/* The following structure represents a single argument for the probe. */
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struct stap_probe_arg
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{
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/* The bitness of this argument. */
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enum stap_arg_bitness bitness;
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/* The corresponding `struct type *' to the bitness. */
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struct type *atype;
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/* The argument converted to an internal GDB expression. */
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struct expression *aexpr;
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};
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typedef struct stap_probe_arg stap_probe_arg_s;
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DEF_VEC_O (stap_probe_arg_s);
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struct stap_probe
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{
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/* Generic information about the probe. This shall be the first element
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of this struct, in order to maintain binary compatibility with the
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`struct probe' and be able to fully abstract it. */
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struct probe p;
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/* If the probe has a semaphore associated, then this is the value of
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it, relative to SECT_OFF_DATA. */
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CORE_ADDR sem_addr;
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/* One if the arguments have been parsed. */
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unsigned int args_parsed : 1;
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union
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{
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const char *text;
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/* Information about each argument. This is an array of `stap_probe_arg',
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with each entry representing one argument. */
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VEC (stap_probe_arg_s) *vec;
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}
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args_u;
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};
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/* When parsing the arguments, we have to establish different precedences
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for the various kinds of asm operators. This enumeration represents those
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precedences.
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This logic behind this is available at
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<http://sourceware.org/binutils/docs/as/Infix-Ops.html#Infix-Ops>, or using
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the command "info '(as)Infix Ops'". */
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enum stap_operand_prec
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{
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/* Lowest precedence, used for non-recognized operands or for the beginning
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of the parsing process. */
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STAP_OPERAND_PREC_NONE = 0,
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/* Precedence of logical OR. */
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STAP_OPERAND_PREC_LOGICAL_OR,
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/* Precedence of logical AND. */
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STAP_OPERAND_PREC_LOGICAL_AND,
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/* Precedence of additive (plus, minus) and comparative (equal, less,
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greater-than, etc) operands. */
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STAP_OPERAND_PREC_ADD_CMP,
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/* Precedence of bitwise operands (bitwise OR, XOR, bitwise AND,
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logical NOT). */
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STAP_OPERAND_PREC_BITWISE,
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/* Precedence of multiplicative operands (multiplication, division,
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remainder, left shift and right shift). */
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STAP_OPERAND_PREC_MUL
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};
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static void stap_parse_argument_1 (struct stap_parse_info *p, int has_lhs,
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enum stap_operand_prec prec);
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static void stap_parse_argument_conditionally (struct stap_parse_info *p);
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/* Returns 1 if *S is an operator, zero otherwise. */
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static int stap_is_operator (const char *op);
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static void
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show_stapexpressiondebug (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("SystemTap Probe expression debugging is %s.\n"),
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value);
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}
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/* Returns the operator precedence level of OP, or STAP_OPERAND_PREC_NONE
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if the operator code was not recognized. */
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static enum stap_operand_prec
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stap_get_operator_prec (enum exp_opcode op)
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{
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switch (op)
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{
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case BINOP_LOGICAL_OR:
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return STAP_OPERAND_PREC_LOGICAL_OR;
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case BINOP_LOGICAL_AND:
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return STAP_OPERAND_PREC_LOGICAL_AND;
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case BINOP_ADD:
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case BINOP_SUB:
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case BINOP_EQUAL:
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case BINOP_NOTEQUAL:
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case BINOP_LESS:
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case BINOP_LEQ:
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case BINOP_GTR:
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case BINOP_GEQ:
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return STAP_OPERAND_PREC_ADD_CMP;
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case BINOP_BITWISE_IOR:
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case BINOP_BITWISE_AND:
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case BINOP_BITWISE_XOR:
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case UNOP_LOGICAL_NOT:
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return STAP_OPERAND_PREC_BITWISE;
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case BINOP_MUL:
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case BINOP_DIV:
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case BINOP_REM:
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case BINOP_LSH:
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case BINOP_RSH:
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return STAP_OPERAND_PREC_MUL;
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default:
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return STAP_OPERAND_PREC_NONE;
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}
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}
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/* Given S, read the operator in it and fills the OP pointer with its code.
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Return 1 on success, zero if the operator was not recognized. */
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static enum exp_opcode
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stap_get_opcode (const char **s)
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{
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const char c = **s;
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enum exp_opcode op;
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*s += 1;
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switch (c)
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{
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case '*':
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op = BINOP_MUL;
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break;
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case '/':
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op = BINOP_DIV;
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break;
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case '%':
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op = BINOP_REM;
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break;
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case '<':
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op = BINOP_LESS;
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if (**s == '<')
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{
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*s += 1;
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op = BINOP_LSH;
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}
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else if (**s == '=')
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{
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*s += 1;
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op = BINOP_LEQ;
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}
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else if (**s == '>')
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{
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*s += 1;
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op = BINOP_NOTEQUAL;
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}
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break;
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case '>':
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op = BINOP_GTR;
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if (**s == '>')
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{
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*s += 1;
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op = BINOP_RSH;
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}
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else if (**s == '=')
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{
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*s += 1;
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op = BINOP_GEQ;
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}
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break;
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case '|':
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op = BINOP_BITWISE_IOR;
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if (**s == '|')
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{
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*s += 1;
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op = BINOP_LOGICAL_OR;
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}
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break;
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case '&':
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op = BINOP_BITWISE_AND;
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if (**s == '&')
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{
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*s += 1;
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op = BINOP_LOGICAL_AND;
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}
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break;
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case '^':
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op = BINOP_BITWISE_XOR;
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break;
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case '!':
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op = UNOP_LOGICAL_NOT;
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break;
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case '+':
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op = BINOP_ADD;
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break;
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case '-':
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op = BINOP_SUB;
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break;
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case '=':
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gdb_assert (**s == '=');
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op = BINOP_EQUAL;
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break;
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default:
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internal_error (__FILE__, __LINE__,
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_("Invalid opcode in expression `%s' for SystemTap"
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"probe"), *s);
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}
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return op;
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}
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/* Given the bitness of the argument, represented by B, return the
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corresponding `struct type *'. */
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static struct type *
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stap_get_expected_argument_type (struct gdbarch *gdbarch,
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enum stap_arg_bitness b)
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{
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switch (b)
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{
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case STAP_ARG_BITNESS_UNDEFINED:
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if (gdbarch_addr_bit (gdbarch) == 32)
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return builtin_type (gdbarch)->builtin_uint32;
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else
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return builtin_type (gdbarch)->builtin_uint64;
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case STAP_ARG_BITNESS_8BIT_UNSIGNED:
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return builtin_type (gdbarch)->builtin_uint8;
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case STAP_ARG_BITNESS_8BIT_SIGNED:
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return builtin_type (gdbarch)->builtin_int8;
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case STAP_ARG_BITNESS_16BIT_UNSIGNED:
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return builtin_type (gdbarch)->builtin_uint16;
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case STAP_ARG_BITNESS_16BIT_SIGNED:
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return builtin_type (gdbarch)->builtin_int16;
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case STAP_ARG_BITNESS_32BIT_SIGNED:
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return builtin_type (gdbarch)->builtin_int32;
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case STAP_ARG_BITNESS_32BIT_UNSIGNED:
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return builtin_type (gdbarch)->builtin_uint32;
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case STAP_ARG_BITNESS_64BIT_SIGNED:
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return builtin_type (gdbarch)->builtin_int64;
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case STAP_ARG_BITNESS_64BIT_UNSIGNED:
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return builtin_type (gdbarch)->builtin_uint64;
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default:
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internal_error (__FILE__, __LINE__,
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_("Undefined bitness for probe."));
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break;
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}
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}
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/* Helper function to check for a generic list of prefixes. GDBARCH
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is the current gdbarch being used. S is the expression being
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analyzed. If R is not NULL, it will be used to return the found
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prefix. PREFIXES is the list of expected prefixes.
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This function does a case-insensitive match.
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Return 1 if any prefix has been found, zero otherwise. */
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static int
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stap_is_generic_prefix (struct gdbarch *gdbarch, const char *s,
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const char **r, const char *const *prefixes)
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{
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const char *const *p;
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if (prefixes == NULL)
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{
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if (r != NULL)
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*r = "";
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return 1;
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}
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for (p = prefixes; *p != NULL; ++p)
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if (strncasecmp (s, *p, strlen (*p)) == 0)
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{
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if (r != NULL)
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*r = *p;
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return 1;
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}
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return 0;
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}
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/* Return 1 if S points to a register prefix, zero otherwise. For a
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description of the arguments, look at stap_is_generic_prefix. */
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static int
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stap_is_register_prefix (struct gdbarch *gdbarch, const char *s,
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const char **r)
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{
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const char *const *t = gdbarch_stap_register_prefixes (gdbarch);
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return stap_is_generic_prefix (gdbarch, s, r, t);
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}
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/* Return 1 if S points to a register indirection prefix, zero
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otherwise. For a description of the arguments, look at
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stap_is_generic_prefix. */
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static int
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stap_is_register_indirection_prefix (struct gdbarch *gdbarch, const char *s,
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const char **r)
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{
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const char *const *t = gdbarch_stap_register_indirection_prefixes (gdbarch);
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return stap_is_generic_prefix (gdbarch, s, r, t);
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}
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/* Return 1 if S points to an integer prefix, zero otherwise. For a
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description of the arguments, look at stap_is_generic_prefix.
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This function takes care of analyzing whether we are dealing with
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an expected integer prefix, or, if there is no integer prefix to be
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expected, whether we are dealing with a digit. It does a
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case-insensitive match. */
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static int
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stap_is_integer_prefix (struct gdbarch *gdbarch, const char *s,
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const char **r)
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{
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const char *const *t = gdbarch_stap_integer_prefixes (gdbarch);
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const char *const *p;
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if (t == NULL)
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{
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/* A NULL value here means that integers do not have a prefix.
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We just check for a digit then. */
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if (r != NULL)
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*r = "";
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return isdigit (*s);
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}
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for (p = t; *p != NULL; ++p)
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{
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size_t len = strlen (*p);
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if ((len == 0 && isdigit (*s))
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|| (len > 0 && strncasecmp (s, *p, len) == 0))
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{
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/* Integers may or may not have a prefix. The "len == 0"
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check covers the case when integers do not have a prefix
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(therefore, we just check if we have a digit). The call
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to "strncasecmp" covers the case when they have a
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prefix. */
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if (r != NULL)
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*r = *p;
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return 1;
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||
}
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}
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return 0;
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}
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|
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/* Helper function to check for a generic list of suffixes. If we are
|
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not expecting any suffixes, then it just returns 1. If we are
|
||
expecting at least one suffix, then it returns 1 if a suffix has
|
||
been found, zero otherwise. GDBARCH is the current gdbarch being
|
||
used. S is the expression being analyzed. If R is not NULL, it
|
||
will be used to return the found suffix. SUFFIXES is the list of
|
||
expected suffixes. This function does a case-insensitive
|
||
match. */
|
||
|
||
static int
|
||
stap_generic_check_suffix (struct gdbarch *gdbarch, const char *s,
|
||
const char **r, const char *const *suffixes)
|
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{
|
||
const char *const *p;
|
||
int found = 0;
|
||
|
||
if (suffixes == NULL)
|
||
{
|
||
if (r != NULL)
|
||
*r = "";
|
||
|
||
return 1;
|
||
}
|
||
|
||
for (p = suffixes; *p != NULL; ++p)
|
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if (strncasecmp (s, *p, strlen (*p)) == 0)
|
||
{
|
||
if (r != NULL)
|
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*r = *p;
|
||
|
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found = 1;
|
||
break;
|
||
}
|
||
|
||
return found;
|
||
}
|
||
|
||
/* Return 1 if S points to an integer suffix, zero otherwise. For a
|
||
description of the arguments, look at
|
||
stap_generic_check_suffix. */
|
||
|
||
static int
|
||
stap_check_integer_suffix (struct gdbarch *gdbarch, const char *s,
|
||
const char **r)
|
||
{
|
||
const char *const *p = gdbarch_stap_integer_suffixes (gdbarch);
|
||
|
||
return stap_generic_check_suffix (gdbarch, s, r, p);
|
||
}
|
||
|
||
/* Return 1 if S points to a register suffix, zero otherwise. For a
|
||
description of the arguments, look at
|
||
stap_generic_check_suffix. */
|
||
|
||
static int
|
||
stap_check_register_suffix (struct gdbarch *gdbarch, const char *s,
|
||
const char **r)
|
||
{
|
||
const char *const *p = gdbarch_stap_register_suffixes (gdbarch);
|
||
|
||
return stap_generic_check_suffix (gdbarch, s, r, p);
|
||
}
|
||
|
||
/* Return 1 if S points to a register indirection suffix, zero
|
||
otherwise. For a description of the arguments, look at
|
||
stap_generic_check_suffix. */
|
||
|
||
static int
|
||
stap_check_register_indirection_suffix (struct gdbarch *gdbarch, const char *s,
|
||
const char **r)
|
||
{
|
||
const char *const *p = gdbarch_stap_register_indirection_suffixes (gdbarch);
|
||
|
||
return stap_generic_check_suffix (gdbarch, s, r, p);
|
||
}
|
||
|
||
/* Function responsible for parsing a register operand according to
|
||
SystemTap parlance. Assuming:
|
||
|
||
RP = register prefix
|
||
RS = register suffix
|
||
RIP = register indirection prefix
|
||
RIS = register indirection suffix
|
||
|
||
Then a register operand can be:
|
||
|
||
[RIP] [RP] REGISTER [RS] [RIS]
|
||
|
||
This function takes care of a register's indirection, displacement and
|
||
direct access. It also takes into consideration the fact that some
|
||
registers are named differently inside and outside GDB, e.g., PPC's
|
||
general-purpose registers are represented by integers in the assembly
|
||
language (e.g., `15' is the 15th general-purpose register), but inside
|
||
GDB they have a prefix (the letter `r') appended. */
|
||
|
||
static void
|
||
stap_parse_register_operand (struct stap_parse_info *p)
|
||
{
|
||
/* Simple flag to indicate whether we have seen a minus signal before
|
||
certain number. */
|
||
int got_minus = 0;
|
||
/* Flags to indicate whether this register access is being displaced and/or
|
||
indirected. */
|
||
int disp_p = 0, indirect_p = 0;
|
||
struct gdbarch *gdbarch = p->gdbarch;
|
||
/* Needed to generate the register name as a part of an expression. */
|
||
struct stoken str;
|
||
/* Variables used to extract the register name from the probe's
|
||
argument. */
|
||
const char *start;
|
||
char *regname;
|
||
int len;
|
||
const char *gdb_reg_prefix = gdbarch_stap_gdb_register_prefix (gdbarch);
|
||
int gdb_reg_prefix_len = gdb_reg_prefix ? strlen (gdb_reg_prefix) : 0;
|
||
const char *gdb_reg_suffix = gdbarch_stap_gdb_register_suffix (gdbarch);
|
||
int gdb_reg_suffix_len = gdb_reg_suffix ? strlen (gdb_reg_suffix) : 0;
|
||
const char *reg_prefix;
|
||
const char *reg_ind_prefix;
|
||
const char *reg_suffix;
|
||
const char *reg_ind_suffix;
|
||
|
||
/* Checking for a displacement argument. */
|
||
if (*p->arg == '+')
|
||
{
|
||
/* If it's a plus sign, we don't need to do anything, just advance the
|
||
pointer. */
|
||
++p->arg;
|
||
}
|
||
|
||
if (*p->arg == '-')
|
||
{
|
||
got_minus = 1;
|
||
++p->arg;
|
||
}
|
||
|
||
if (isdigit (*p->arg))
|
||
{
|
||
/* The value of the displacement. */
|
||
long displacement;
|
||
char *endp;
|
||
|
||
disp_p = 1;
|
||
displacement = strtol (p->arg, &endp, 10);
|
||
p->arg = endp;
|
||
|
||
/* Generating the expression for the displacement. */
|
||
write_exp_elt_opcode (&p->pstate, OP_LONG);
|
||
write_exp_elt_type (&p->pstate, builtin_type (gdbarch)->builtin_long);
|
||
write_exp_elt_longcst (&p->pstate, displacement);
|
||
write_exp_elt_opcode (&p->pstate, OP_LONG);
|
||
if (got_minus)
|
||
write_exp_elt_opcode (&p->pstate, UNOP_NEG);
|
||
}
|
||
|
||
/* Getting rid of register indirection prefix. */
|
||
if (stap_is_register_indirection_prefix (gdbarch, p->arg, ®_ind_prefix))
|
||
{
|
||
indirect_p = 1;
|
||
p->arg += strlen (reg_ind_prefix);
|
||
}
|
||
|
||
if (disp_p && !indirect_p)
|
||
error (_("Invalid register displacement syntax on expression `%s'."),
|
||
p->saved_arg);
|
||
|
||
/* Getting rid of register prefix. */
|
||
if (stap_is_register_prefix (gdbarch, p->arg, ®_prefix))
|
||
p->arg += strlen (reg_prefix);
|
||
|
||
/* Now we should have only the register name. Let's extract it and get
|
||
the associated number. */
|
||
start = p->arg;
|
||
|
||
/* We assume the register name is composed by letters and numbers. */
|
||
while (isalnum (*p->arg))
|
||
++p->arg;
|
||
|
||
len = p->arg - start;
|
||
|
||
regname = alloca (len + gdb_reg_prefix_len + gdb_reg_suffix_len + 1);
|
||
regname[0] = '\0';
|
||
|
||
/* We only add the GDB's register prefix/suffix if we are dealing with
|
||
a numeric register. */
|
||
if (gdb_reg_prefix && isdigit (*start))
|
||
{
|
||
strncpy (regname, gdb_reg_prefix, gdb_reg_prefix_len);
|
||
strncpy (regname + gdb_reg_prefix_len, start, len);
|
||
|
||
if (gdb_reg_suffix)
|
||
strncpy (regname + gdb_reg_prefix_len + len,
|
||
gdb_reg_suffix, gdb_reg_suffix_len);
|
||
|
||
len += gdb_reg_prefix_len + gdb_reg_suffix_len;
|
||
}
|
||
else
|
||
strncpy (regname, start, len);
|
||
|
||
regname[len] = '\0';
|
||
|
||
/* Is this a valid register name? */
|
||
if (user_reg_map_name_to_regnum (gdbarch, regname, len) == -1)
|
||
error (_("Invalid register name `%s' on expression `%s'."),
|
||
regname, p->saved_arg);
|
||
|
||
write_exp_elt_opcode (&p->pstate, OP_REGISTER);
|
||
str.ptr = regname;
|
||
str.length = len;
|
||
write_exp_string (&p->pstate, str);
|
||
write_exp_elt_opcode (&p->pstate, OP_REGISTER);
|
||
|
||
if (indirect_p)
|
||
{
|
||
if (disp_p)
|
||
write_exp_elt_opcode (&p->pstate, BINOP_ADD);
|
||
|
||
/* Casting to the expected type. */
|
||
write_exp_elt_opcode (&p->pstate, UNOP_CAST);
|
||
write_exp_elt_type (&p->pstate, lookup_pointer_type (p->arg_type));
|
||
write_exp_elt_opcode (&p->pstate, UNOP_CAST);
|
||
|
||
write_exp_elt_opcode (&p->pstate, UNOP_IND);
|
||
}
|
||
|
||
/* Getting rid of the register name suffix. */
|
||
if (stap_check_register_suffix (gdbarch, p->arg, ®_suffix))
|
||
p->arg += strlen (reg_suffix);
|
||
else
|
||
error (_("Missing register name suffix on expression `%s'."),
|
||
p->saved_arg);
|
||
|
||
/* Getting rid of the register indirection suffix. */
|
||
if (indirect_p)
|
||
{
|
||
if (stap_check_register_indirection_suffix (gdbarch, p->arg,
|
||
®_ind_suffix))
|
||
p->arg += strlen (reg_ind_suffix);
|
||
else
|
||
error (_("Missing indirection suffix on expression `%s'."),
|
||
p->saved_arg);
|
||
}
|
||
}
|
||
|
||
/* This function is responsible for parsing a single operand.
|
||
|
||
A single operand can be:
|
||
|
||
- an unary operation (e.g., `-5', `~2', or even with subexpressions
|
||
like `-(2 + 1)')
|
||
- a register displacement, which will be treated as a register
|
||
operand (e.g., `-4(%eax)' on x86)
|
||
- a numeric constant, or
|
||
- a register operand (see function `stap_parse_register_operand')
|
||
|
||
The function also calls special-handling functions to deal with
|
||
unrecognized operands, allowing arch-specific parsers to be
|
||
created. */
|
||
|
||
static void
|
||
stap_parse_single_operand (struct stap_parse_info *p)
|
||
{
|
||
struct gdbarch *gdbarch = p->gdbarch;
|
||
const char *int_prefix = NULL;
|
||
|
||
/* We first try to parse this token as a "special token". */
|
||
if (gdbarch_stap_parse_special_token_p (gdbarch))
|
||
if (gdbarch_stap_parse_special_token (gdbarch, p) != 0)
|
||
{
|
||
/* If the return value of the above function is not zero,
|
||
it means it successfully parsed the special token.
|
||
|
||
If it is NULL, we try to parse it using our method. */
|
||
return;
|
||
}
|
||
|
||
if (*p->arg == '-' || *p->arg == '~' || *p->arg == '+')
|
||
{
|
||
char c = *p->arg;
|
||
/* We use this variable to do a lookahead. */
|
||
const char *tmp = p->arg;
|
||
int has_digit = 0;
|
||
|
||
/* Skipping signal. */
|
||
++tmp;
|
||
|
||
/* This is an unary operation. Here is a list of allowed tokens
|
||
here:
|
||
|
||
- numeric literal;
|
||
- number (from register displacement)
|
||
- subexpression (beginning with `(')
|
||
|
||
We handle the register displacement here, and the other cases
|
||
recursively. */
|
||
if (p->inside_paren_p)
|
||
tmp = skip_spaces_const (tmp);
|
||
|
||
while (isdigit (*tmp))
|
||
{
|
||
/* We skip the digit here because we are only interested in
|
||
knowing what kind of unary operation this is. The digit
|
||
will be handled by one of the functions that will be
|
||
called below ('stap_parse_argument_conditionally' or
|
||
'stap_parse_register_operand'). */
|
||
++tmp;
|
||
has_digit = 1;
|
||
}
|
||
|
||
if (has_digit && stap_is_register_indirection_prefix (gdbarch, tmp,
|
||
NULL))
|
||
{
|
||
/* If we are here, it means it is a displacement. The only
|
||
operations allowed here are `-' and `+'. */
|
||
if (c == '~')
|
||
error (_("Invalid operator `%c' for register displacement "
|
||
"on expression `%s'."), c, p->saved_arg);
|
||
|
||
stap_parse_register_operand (p);
|
||
}
|
||
else
|
||
{
|
||
/* This is not a displacement. We skip the operator, and
|
||
deal with it when the recursion returns. */
|
||
++p->arg;
|
||
stap_parse_argument_conditionally (p);
|
||
if (c == '-')
|
||
write_exp_elt_opcode (&p->pstate, UNOP_NEG);
|
||
else if (c == '~')
|
||
write_exp_elt_opcode (&p->pstate, UNOP_COMPLEMENT);
|
||
}
|
||
}
|
||
else if (isdigit (*p->arg))
|
||
{
|
||
/* A temporary variable, needed for lookahead. */
|
||
const char *tmp = p->arg;
|
||
char *endp;
|
||
long number;
|
||
|
||
/* We can be dealing with a numeric constant, or with a register
|
||
displacement. */
|
||
number = strtol (tmp, &endp, 10);
|
||
tmp = endp;
|
||
|
||
if (p->inside_paren_p)
|
||
tmp = skip_spaces_const (tmp);
|
||
|
||
/* If "stap_is_integer_prefix" returns true, it means we can
|
||
accept integers without a prefix here. But we also need to
|
||
check whether the next token (i.e., "tmp") is not a register
|
||
indirection prefix. */
|
||
if (stap_is_integer_prefix (gdbarch, p->arg, NULL)
|
||
&& !stap_is_register_indirection_prefix (gdbarch, tmp, NULL))
|
||
{
|
||
const char *int_suffix;
|
||
|
||
/* We are dealing with a numeric constant. */
|
||
write_exp_elt_opcode (&p->pstate, OP_LONG);
|
||
write_exp_elt_type (&p->pstate,
|
||
builtin_type (gdbarch)->builtin_long);
|
||
write_exp_elt_longcst (&p->pstate, number);
|
||
write_exp_elt_opcode (&p->pstate, OP_LONG);
|
||
|
||
p->arg = tmp;
|
||
|
||
if (stap_check_integer_suffix (gdbarch, p->arg, &int_suffix))
|
||
p->arg += strlen (int_suffix);
|
||
else
|
||
error (_("Invalid constant suffix on expression `%s'."),
|
||
p->saved_arg);
|
||
}
|
||
else if (stap_is_register_indirection_prefix (gdbarch, tmp, NULL))
|
||
stap_parse_register_operand (p);
|
||
else
|
||
error (_("Unknown numeric token on expression `%s'."),
|
||
p->saved_arg);
|
||
}
|
||
else if (stap_is_integer_prefix (gdbarch, p->arg, &int_prefix))
|
||
{
|
||
/* We are dealing with a numeric constant. */
|
||
long number;
|
||
char *endp;
|
||
const char *int_suffix;
|
||
|
||
p->arg += strlen (int_prefix);
|
||
number = strtol (p->arg, &endp, 10);
|
||
p->arg = endp;
|
||
|
||
write_exp_elt_opcode (&p->pstate, OP_LONG);
|
||
write_exp_elt_type (&p->pstate, builtin_type (gdbarch)->builtin_long);
|
||
write_exp_elt_longcst (&p->pstate, number);
|
||
write_exp_elt_opcode (&p->pstate, OP_LONG);
|
||
|
||
if (stap_check_integer_suffix (gdbarch, p->arg, &int_suffix))
|
||
p->arg += strlen (int_suffix);
|
||
else
|
||
error (_("Invalid constant suffix on expression `%s'."),
|
||
p->saved_arg);
|
||
}
|
||
else if (stap_is_register_prefix (gdbarch, p->arg, NULL)
|
||
|| stap_is_register_indirection_prefix (gdbarch, p->arg, NULL))
|
||
stap_parse_register_operand (p);
|
||
else
|
||
error (_("Operator `%c' not recognized on expression `%s'."),
|
||
*p->arg, p->saved_arg);
|
||
}
|
||
|
||
/* This function parses an argument conditionally, based on single or
|
||
non-single operands. A non-single operand would be a parenthesized
|
||
expression (e.g., `(2 + 1)'), and a single operand is anything that
|
||
starts with `-', `~', `+' (i.e., unary operators), a digit, or
|
||
something recognized by `gdbarch_stap_is_single_operand'. */
|
||
|
||
static void
|
||
stap_parse_argument_conditionally (struct stap_parse_info *p)
|
||
{
|
||
gdb_assert (gdbarch_stap_is_single_operand_p (p->gdbarch));
|
||
|
||
if (*p->arg == '-' || *p->arg == '~' || *p->arg == '+' /* Unary. */
|
||
|| isdigit (*p->arg)
|
||
|| gdbarch_stap_is_single_operand (p->gdbarch, p->arg))
|
||
stap_parse_single_operand (p);
|
||
else if (*p->arg == '(')
|
||
{
|
||
/* We are dealing with a parenthesized operand. It means we
|
||
have to parse it as it was a separate expression, without
|
||
left-side or precedence. */
|
||
++p->arg;
|
||
p->arg = skip_spaces_const (p->arg);
|
||
++p->inside_paren_p;
|
||
|
||
stap_parse_argument_1 (p, 0, STAP_OPERAND_PREC_NONE);
|
||
|
||
--p->inside_paren_p;
|
||
if (*p->arg != ')')
|
||
error (_("Missign close-paren on expression `%s'."),
|
||
p->saved_arg);
|
||
|
||
++p->arg;
|
||
if (p->inside_paren_p)
|
||
p->arg = skip_spaces_const (p->arg);
|
||
}
|
||
else
|
||
error (_("Cannot parse expression `%s'."), p->saved_arg);
|
||
}
|
||
|
||
/* Helper function for `stap_parse_argument'. Please, see its comments to
|
||
better understand what this function does. */
|
||
|
||
static void
|
||
stap_parse_argument_1 (struct stap_parse_info *p, int has_lhs,
|
||
enum stap_operand_prec prec)
|
||
{
|
||
/* This is an operator-precedence parser.
|
||
|
||
We work with left- and right-sides of expressions, and
|
||
parse them depending on the precedence of the operators
|
||
we find. */
|
||
|
||
gdb_assert (p->arg != NULL);
|
||
|
||
if (p->inside_paren_p)
|
||
p->arg = skip_spaces_const (p->arg);
|
||
|
||
if (!has_lhs)
|
||
{
|
||
/* We were called without a left-side, either because this is the
|
||
first call, or because we were called to parse a parenthesized
|
||
expression. It doesn't really matter; we have to parse the
|
||
left-side in order to continue the process. */
|
||
stap_parse_argument_conditionally (p);
|
||
}
|
||
|
||
/* Start to parse the right-side, and to "join" left and right sides
|
||
depending on the operation specified.
|
||
|
||
This loop shall continue until we run out of characters in the input,
|
||
or until we find a close-parenthesis, which means that we've reached
|
||
the end of a sub-expression. */
|
||
while (*p->arg != '\0' && *p->arg != ')' && !isspace (*p->arg))
|
||
{
|
||
const char *tmp_exp_buf;
|
||
enum exp_opcode opcode;
|
||
enum stap_operand_prec cur_prec;
|
||
|
||
if (!stap_is_operator (p->arg))
|
||
error (_("Invalid operator `%c' on expression `%s'."), *p->arg,
|
||
p->saved_arg);
|
||
|
||
/* We have to save the current value of the expression buffer because
|
||
the `stap_get_opcode' modifies it in order to get the current
|
||
operator. If this operator's precedence is lower than PREC, we
|
||
should return and not advance the expression buffer pointer. */
|
||
tmp_exp_buf = p->arg;
|
||
opcode = stap_get_opcode (&tmp_exp_buf);
|
||
|
||
cur_prec = stap_get_operator_prec (opcode);
|
||
if (cur_prec < prec)
|
||
{
|
||
/* If the precedence of the operator that we are seeing now is
|
||
lower than the precedence of the first operator seen before
|
||
this parsing process began, it means we should stop parsing
|
||
and return. */
|
||
break;
|
||
}
|
||
|
||
p->arg = tmp_exp_buf;
|
||
if (p->inside_paren_p)
|
||
p->arg = skip_spaces_const (p->arg);
|
||
|
||
/* Parse the right-side of the expression. */
|
||
stap_parse_argument_conditionally (p);
|
||
|
||
/* While we still have operators, try to parse another
|
||
right-side, but using the current right-side as a left-side. */
|
||
while (*p->arg != '\0' && stap_is_operator (p->arg))
|
||
{
|
||
enum exp_opcode lookahead_opcode;
|
||
enum stap_operand_prec lookahead_prec;
|
||
|
||
/* Saving the current expression buffer position. The explanation
|
||
is the same as above. */
|
||
tmp_exp_buf = p->arg;
|
||
lookahead_opcode = stap_get_opcode (&tmp_exp_buf);
|
||
lookahead_prec = stap_get_operator_prec (lookahead_opcode);
|
||
|
||
if (lookahead_prec <= prec)
|
||
{
|
||
/* If we are dealing with an operator whose precedence is lower
|
||
than the first one, just abandon the attempt. */
|
||
break;
|
||
}
|
||
|
||
/* Parse the right-side of the expression, but since we already
|
||
have a left-side at this point, set `has_lhs' to 1. */
|
||
stap_parse_argument_1 (p, 1, lookahead_prec);
|
||
}
|
||
|
||
write_exp_elt_opcode (&p->pstate, opcode);
|
||
}
|
||
}
|
||
|
||
/* Parse a probe's argument.
|
||
|
||
Assuming that:
|
||
|
||
LP = literal integer prefix
|
||
LS = literal integer suffix
|
||
|
||
RP = register prefix
|
||
RS = register suffix
|
||
|
||
RIP = register indirection prefix
|
||
RIS = register indirection suffix
|
||
|
||
This routine assumes that arguments' tokens are of the form:
|
||
|
||
- [LP] NUMBER [LS]
|
||
- [RP] REGISTER [RS]
|
||
- [RIP] [RP] REGISTER [RS] [RIS]
|
||
- If we find a number without LP, we try to parse it as a literal integer
|
||
constant (if LP == NULL), or as a register displacement.
|
||
- We count parenthesis, and only skip whitespaces if we are inside them.
|
||
- If we find an operator, we skip it.
|
||
|
||
This function can also call a special function that will try to match
|
||
unknown tokens. It will return 1 if the argument has been parsed
|
||
successfully, or zero otherwise. */
|
||
|
||
static struct expression *
|
||
stap_parse_argument (const char **arg, struct type *atype,
|
||
struct gdbarch *gdbarch)
|
||
{
|
||
struct stap_parse_info p;
|
||
struct cleanup *back_to;
|
||
|
||
/* We need to initialize the expression buffer, in order to begin
|
||
our parsing efforts. We use language_c here because we may need
|
||
to do pointer arithmetics. */
|
||
initialize_expout (&p.pstate, 10, language_def (language_c), gdbarch);
|
||
back_to = make_cleanup (free_current_contents, &p.pstate.expout);
|
||
|
||
p.saved_arg = *arg;
|
||
p.arg = *arg;
|
||
p.arg_type = atype;
|
||
p.gdbarch = gdbarch;
|
||
p.inside_paren_p = 0;
|
||
|
||
stap_parse_argument_1 (&p, 0, STAP_OPERAND_PREC_NONE);
|
||
|
||
discard_cleanups (back_to);
|
||
|
||
gdb_assert (p.inside_paren_p == 0);
|
||
|
||
/* Casting the final expression to the appropriate type. */
|
||
write_exp_elt_opcode (&p.pstate, UNOP_CAST);
|
||
write_exp_elt_type (&p.pstate, atype);
|
||
write_exp_elt_opcode (&p.pstate, UNOP_CAST);
|
||
|
||
reallocate_expout (&p.pstate);
|
||
|
||
p.arg = skip_spaces_const (p.arg);
|
||
*arg = p.arg;
|
||
|
||
/* We can safely return EXPOUT here. */
|
||
return p.pstate.expout;
|
||
}
|
||
|
||
/* Function which parses an argument string from PROBE, correctly splitting
|
||
the arguments and storing their information in properly ways.
|
||
|
||
Consider the following argument string (x86 syntax):
|
||
|
||
`4@%eax 4@$10'
|
||
|
||
We have two arguments, `%eax' and `$10', both with 32-bit unsigned bitness.
|
||
This function basically handles them, properly filling some structures with
|
||
this information. */
|
||
|
||
static void
|
||
stap_parse_probe_arguments (struct stap_probe *probe, struct gdbarch *gdbarch)
|
||
{
|
||
const char *cur;
|
||
|
||
gdb_assert (!probe->args_parsed);
|
||
cur = probe->args_u.text;
|
||
probe->args_parsed = 1;
|
||
probe->args_u.vec = NULL;
|
||
|
||
if (cur == NULL || *cur == '\0' || *cur == ':')
|
||
return;
|
||
|
||
while (*cur != '\0')
|
||
{
|
||
struct stap_probe_arg arg;
|
||
enum stap_arg_bitness b;
|
||
int got_minus = 0;
|
||
struct expression *expr;
|
||
|
||
memset (&arg, 0, sizeof (arg));
|
||
|
||
/* We expect to find something like:
|
||
|
||
N@OP
|
||
|
||
Where `N' can be [+,-][1,2,4,8]. This is not mandatory, so
|
||
we check it here. If we don't find it, go to the next
|
||
state. */
|
||
if ((cur[0] == '-' && isdigit (cur[1]) && cur[2] == '@')
|
||
|| (isdigit (cur[0]) && cur[1] == '@'))
|
||
{
|
||
if (*cur == '-')
|
||
{
|
||
/* Discard the `-'. */
|
||
++cur;
|
||
got_minus = 1;
|
||
}
|
||
|
||
/* Defining the bitness. */
|
||
switch (*cur)
|
||
{
|
||
case '1':
|
||
b = (got_minus ? STAP_ARG_BITNESS_8BIT_SIGNED
|
||
: STAP_ARG_BITNESS_8BIT_UNSIGNED);
|
||
break;
|
||
|
||
case '2':
|
||
b = (got_minus ? STAP_ARG_BITNESS_16BIT_SIGNED
|
||
: STAP_ARG_BITNESS_16BIT_UNSIGNED);
|
||
break;
|
||
|
||
case '4':
|
||
b = (got_minus ? STAP_ARG_BITNESS_32BIT_SIGNED
|
||
: STAP_ARG_BITNESS_32BIT_UNSIGNED);
|
||
break;
|
||
|
||
case '8':
|
||
b = (got_minus ? STAP_ARG_BITNESS_64BIT_SIGNED
|
||
: STAP_ARG_BITNESS_64BIT_UNSIGNED);
|
||
break;
|
||
|
||
default:
|
||
{
|
||
/* We have an error, because we don't expect anything
|
||
except 1, 2, 4 and 8. */
|
||
warning (_("unrecognized bitness %s%c' for probe `%s'"),
|
||
got_minus ? "`-" : "`", *cur, probe->p.name);
|
||
return;
|
||
}
|
||
}
|
||
|
||
arg.bitness = b;
|
||
|
||
/* Discard the number and the `@' sign. */
|
||
cur += 2;
|
||
}
|
||
else
|
||
arg.bitness = STAP_ARG_BITNESS_UNDEFINED;
|
||
|
||
arg.atype = stap_get_expected_argument_type (gdbarch, arg.bitness);
|
||
|
||
expr = stap_parse_argument (&cur, arg.atype, gdbarch);
|
||
|
||
if (stap_expression_debug)
|
||
dump_raw_expression (expr, gdb_stdlog,
|
||
"before conversion to prefix form");
|
||
|
||
prefixify_expression (expr);
|
||
|
||
if (stap_expression_debug)
|
||
dump_prefix_expression (expr, gdb_stdlog);
|
||
|
||
arg.aexpr = expr;
|
||
|
||
/* Start it over again. */
|
||
cur = skip_spaces_const (cur);
|
||
|
||
VEC_safe_push (stap_probe_arg_s, probe->args_u.vec, &arg);
|
||
}
|
||
}
|
||
|
||
/* Implementation of the get_probe_address method. */
|
||
|
||
static CORE_ADDR
|
||
stap_get_probe_address (struct probe *probe, struct objfile *objfile)
|
||
{
|
||
return probe->address + ANOFFSET (objfile->section_offsets,
|
||
SECT_OFF_DATA (objfile));
|
||
}
|
||
|
||
/* Given PROBE, returns the number of arguments present in that probe's
|
||
argument string. */
|
||
|
||
static unsigned
|
||
stap_get_probe_argument_count (struct probe *probe_generic,
|
||
struct frame_info *frame)
|
||
{
|
||
struct stap_probe *probe = (struct stap_probe *) probe_generic;
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
|
||
gdb_assert (probe_generic->pops == &stap_probe_ops);
|
||
|
||
if (!probe->args_parsed)
|
||
{
|
||
if (can_evaluate_probe_arguments (probe_generic))
|
||
stap_parse_probe_arguments (probe, gdbarch);
|
||
else
|
||
{
|
||
static int have_warned_stap_incomplete = 0;
|
||
|
||
if (!have_warned_stap_incomplete)
|
||
{
|
||
warning (_(
|
||
"The SystemTap SDT probe support is not fully implemented on this target;\n"
|
||
"you will not be able to inspect the arguments of the probes.\n"
|
||
"Please report a bug against GDB requesting a port to this target."));
|
||
have_warned_stap_incomplete = 1;
|
||
}
|
||
|
||
/* Marking the arguments as "already parsed". */
|
||
probe->args_u.vec = NULL;
|
||
probe->args_parsed = 1;
|
||
}
|
||
}
|
||
|
||
gdb_assert (probe->args_parsed);
|
||
return VEC_length (stap_probe_arg_s, probe->args_u.vec);
|
||
}
|
||
|
||
/* Return 1 if OP is a valid operator inside a probe argument, or zero
|
||
otherwise. */
|
||
|
||
static int
|
||
stap_is_operator (const char *op)
|
||
{
|
||
int ret = 1;
|
||
|
||
switch (*op)
|
||
{
|
||
case '*':
|
||
case '/':
|
||
case '%':
|
||
case '^':
|
||
case '!':
|
||
case '+':
|
||
case '-':
|
||
case '<':
|
||
case '>':
|
||
case '|':
|
||
case '&':
|
||
break;
|
||
|
||
case '=':
|
||
if (op[1] != '=')
|
||
ret = 0;
|
||
break;
|
||
|
||
default:
|
||
/* We didn't find any operator. */
|
||
ret = 0;
|
||
}
|
||
|
||
return ret;
|
||
}
|
||
|
||
static struct stap_probe_arg *
|
||
stap_get_arg (struct stap_probe *probe, unsigned n, struct gdbarch *gdbarch)
|
||
{
|
||
if (!probe->args_parsed)
|
||
stap_parse_probe_arguments (probe, gdbarch);
|
||
|
||
return VEC_index (stap_probe_arg_s, probe->args_u.vec, n);
|
||
}
|
||
|
||
/* Implement the `can_evaluate_probe_arguments' method of probe_ops. */
|
||
|
||
static int
|
||
stap_can_evaluate_probe_arguments (struct probe *probe_generic)
|
||
{
|
||
struct stap_probe *stap_probe = (struct stap_probe *) probe_generic;
|
||
struct gdbarch *gdbarch = stap_probe->p.arch;
|
||
|
||
/* For SystemTap probes, we have to guarantee that the method
|
||
stap_is_single_operand is defined on gdbarch. If it is not, then it
|
||
means that argument evaluation is not implemented on this target. */
|
||
return gdbarch_stap_is_single_operand_p (gdbarch);
|
||
}
|
||
|
||
/* Evaluate the probe's argument N (indexed from 0), returning a value
|
||
corresponding to it. Assertion is thrown if N does not exist. */
|
||
|
||
static struct value *
|
||
stap_evaluate_probe_argument (struct probe *probe_generic, unsigned n,
|
||
struct frame_info *frame)
|
||
{
|
||
struct stap_probe *stap_probe = (struct stap_probe *) probe_generic;
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
struct stap_probe_arg *arg;
|
||
int pos = 0;
|
||
|
||
gdb_assert (probe_generic->pops == &stap_probe_ops);
|
||
|
||
arg = stap_get_arg (stap_probe, n, gdbarch);
|
||
return evaluate_subexp_standard (arg->atype, arg->aexpr, &pos, EVAL_NORMAL);
|
||
}
|
||
|
||
/* Compile the probe's argument N (indexed from 0) to agent expression.
|
||
Assertion is thrown if N does not exist. */
|
||
|
||
static void
|
||
stap_compile_to_ax (struct probe *probe_generic, struct agent_expr *expr,
|
||
struct axs_value *value, unsigned n)
|
||
{
|
||
struct stap_probe *stap_probe = (struct stap_probe *) probe_generic;
|
||
struct stap_probe_arg *arg;
|
||
union exp_element *pc;
|
||
|
||
gdb_assert (probe_generic->pops == &stap_probe_ops);
|
||
|
||
arg = stap_get_arg (stap_probe, n, expr->gdbarch);
|
||
|
||
pc = arg->aexpr->elts;
|
||
gen_expr (arg->aexpr, &pc, expr, value);
|
||
|
||
require_rvalue (expr, value);
|
||
value->type = arg->atype;
|
||
}
|
||
|
||
/* Destroy (free) the data related to PROBE. PROBE memory itself is not feed
|
||
as it is allocated on an obstack. */
|
||
|
||
static void
|
||
stap_probe_destroy (struct probe *probe_generic)
|
||
{
|
||
struct stap_probe *probe = (struct stap_probe *) probe_generic;
|
||
|
||
gdb_assert (probe_generic->pops == &stap_probe_ops);
|
||
|
||
if (probe->args_parsed)
|
||
{
|
||
struct stap_probe_arg *arg;
|
||
int ix;
|
||
|
||
for (ix = 0; VEC_iterate (stap_probe_arg_s, probe->args_u.vec, ix, arg);
|
||
++ix)
|
||
xfree (arg->aexpr);
|
||
VEC_free (stap_probe_arg_s, probe->args_u.vec);
|
||
}
|
||
}
|
||
|
||
|
||
|
||
/* Set or clear a SystemTap semaphore. ADDRESS is the semaphore's
|
||
address. SET is zero if the semaphore should be cleared, or one
|
||
if it should be set. This is a helper function for `stap_semaphore_down'
|
||
and `stap_semaphore_up'. */
|
||
|
||
static void
|
||
stap_modify_semaphore (CORE_ADDR address, int set, struct gdbarch *gdbarch)
|
||
{
|
||
gdb_byte bytes[sizeof (LONGEST)];
|
||
/* The ABI specifies "unsigned short". */
|
||
struct type *type = builtin_type (gdbarch)->builtin_unsigned_short;
|
||
ULONGEST value;
|
||
|
||
if (address == 0)
|
||
return;
|
||
|
||
/* Swallow errors. */
|
||
if (target_read_memory (address, bytes, TYPE_LENGTH (type)) != 0)
|
||
{
|
||
warning (_("Could not read the value of a SystemTap semaphore."));
|
||
return;
|
||
}
|
||
|
||
value = extract_unsigned_integer (bytes, TYPE_LENGTH (type),
|
||
gdbarch_byte_order (gdbarch));
|
||
/* Note that we explicitly don't worry about overflow or
|
||
underflow. */
|
||
if (set)
|
||
++value;
|
||
else
|
||
--value;
|
||
|
||
store_unsigned_integer (bytes, TYPE_LENGTH (type),
|
||
gdbarch_byte_order (gdbarch), value);
|
||
|
||
if (target_write_memory (address, bytes, TYPE_LENGTH (type)) != 0)
|
||
warning (_("Could not write the value of a SystemTap semaphore."));
|
||
}
|
||
|
||
/* Set a SystemTap semaphore. SEM is the semaphore's address. Semaphores
|
||
act as reference counters, so calls to this function must be paired with
|
||
calls to `stap_semaphore_down'.
|
||
|
||
This function and `stap_semaphore_down' race with another tool changing
|
||
the probes, but that is too rare to care. */
|
||
|
||
static void
|
||
stap_set_semaphore (struct probe *probe_generic, struct objfile *objfile,
|
||
struct gdbarch *gdbarch)
|
||
{
|
||
struct stap_probe *probe = (struct stap_probe *) probe_generic;
|
||
CORE_ADDR addr;
|
||
|
||
gdb_assert (probe_generic->pops == &stap_probe_ops);
|
||
|
||
addr = (probe->sem_addr
|
||
+ ANOFFSET (objfile->section_offsets, SECT_OFF_DATA (objfile)));
|
||
stap_modify_semaphore (addr, 1, gdbarch);
|
||
}
|
||
|
||
/* Clear a SystemTap semaphore. SEM is the semaphore's address. */
|
||
|
||
static void
|
||
stap_clear_semaphore (struct probe *probe_generic, struct objfile *objfile,
|
||
struct gdbarch *gdbarch)
|
||
{
|
||
struct stap_probe *probe = (struct stap_probe *) probe_generic;
|
||
CORE_ADDR addr;
|
||
|
||
gdb_assert (probe_generic->pops == &stap_probe_ops);
|
||
|
||
addr = (probe->sem_addr
|
||
+ ANOFFSET (objfile->section_offsets, SECT_OFF_DATA (objfile)));
|
||
stap_modify_semaphore (addr, 0, gdbarch);
|
||
}
|
||
|
||
/* Helper function that parses the information contained in a
|
||
SystemTap's probe. Basically, the information consists in:
|
||
|
||
- Probe's PC address;
|
||
- Link-time section address of `.stapsdt.base' section;
|
||
- Link-time address of the semaphore variable, or ZERO if the
|
||
probe doesn't have an associated semaphore;
|
||
- Probe's provider name;
|
||
- Probe's name;
|
||
- Probe's argument format
|
||
|
||
This function returns 1 if the handling was successful, and zero
|
||
otherwise. */
|
||
|
||
static void
|
||
handle_stap_probe (struct objfile *objfile, struct sdt_note *el,
|
||
VEC (probe_p) **probesp, CORE_ADDR base)
|
||
{
|
||
bfd *abfd = objfile->obfd;
|
||
int size = bfd_get_arch_size (abfd) / 8;
|
||
struct gdbarch *gdbarch = get_objfile_arch (objfile);
|
||
struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
|
||
CORE_ADDR base_ref;
|
||
const char *probe_args = NULL;
|
||
struct stap_probe *ret;
|
||
|
||
ret = obstack_alloc (&objfile->per_bfd->storage_obstack, sizeof (*ret));
|
||
ret->p.pops = &stap_probe_ops;
|
||
ret->p.arch = gdbarch;
|
||
|
||
/* Provider and the name of the probe. */
|
||
ret->p.provider = (char *) &el->data[3 * size];
|
||
ret->p.name = memchr (ret->p.provider, '\0',
|
||
(char *) el->data + el->size - ret->p.provider);
|
||
/* Making sure there is a name. */
|
||
if (ret->p.name == NULL)
|
||
{
|
||
complaint (&symfile_complaints, _("corrupt probe name when "
|
||
"reading `%s'"),
|
||
objfile_name (objfile));
|
||
|
||
/* There is no way to use a probe without a name or a provider, so
|
||
returning zero here makes sense. */
|
||
return;
|
||
}
|
||
else
|
||
++ret->p.name;
|
||
|
||
/* Retrieving the probe's address. */
|
||
ret->p.address = extract_typed_address (&el->data[0], ptr_type);
|
||
|
||
/* Link-time sh_addr of `.stapsdt.base' section. */
|
||
base_ref = extract_typed_address (&el->data[size], ptr_type);
|
||
|
||
/* Semaphore address. */
|
||
ret->sem_addr = extract_typed_address (&el->data[2 * size], ptr_type);
|
||
|
||
ret->p.address += base - base_ref;
|
||
if (ret->sem_addr != 0)
|
||
ret->sem_addr += base - base_ref;
|
||
|
||
/* Arguments. We can only extract the argument format if there is a valid
|
||
name for this probe. */
|
||
probe_args = memchr (ret->p.name, '\0',
|
||
(char *) el->data + el->size - ret->p.name);
|
||
|
||
if (probe_args != NULL)
|
||
++probe_args;
|
||
|
||
if (probe_args == NULL
|
||
|| (memchr (probe_args, '\0', (char *) el->data + el->size - ret->p.name)
|
||
!= el->data + el->size - 1))
|
||
{
|
||
complaint (&symfile_complaints, _("corrupt probe argument when "
|
||
"reading `%s'"),
|
||
objfile_name (objfile));
|
||
/* If the argument string is NULL, it means some problem happened with
|
||
it. So we return 0. */
|
||
return;
|
||
}
|
||
|
||
ret->args_parsed = 0;
|
||
ret->args_u.text = (void *) probe_args;
|
||
|
||
/* Successfully created probe. */
|
||
VEC_safe_push (probe_p, *probesp, (struct probe *) ret);
|
||
}
|
||
|
||
/* Helper function which tries to find the base address of the SystemTap
|
||
base section named STAP_BASE_SECTION_NAME. */
|
||
|
||
static void
|
||
get_stap_base_address_1 (bfd *abfd, asection *sect, void *obj)
|
||
{
|
||
asection **ret = obj;
|
||
|
||
if ((sect->flags & (SEC_DATA | SEC_ALLOC | SEC_HAS_CONTENTS))
|
||
&& sect->name && !strcmp (sect->name, STAP_BASE_SECTION_NAME))
|
||
*ret = sect;
|
||
}
|
||
|
||
/* Helper function which iterates over every section in the BFD file,
|
||
trying to find the base address of the SystemTap base section.
|
||
Returns 1 if found (setting BASE to the proper value), zero otherwise. */
|
||
|
||
static int
|
||
get_stap_base_address (bfd *obfd, bfd_vma *base)
|
||
{
|
||
asection *ret = NULL;
|
||
|
||
bfd_map_over_sections (obfd, get_stap_base_address_1, (void *) &ret);
|
||
|
||
if (ret == NULL)
|
||
{
|
||
complaint (&symfile_complaints, _("could not obtain base address for "
|
||
"SystemTap section on objfile `%s'."),
|
||
obfd->filename);
|
||
return 0;
|
||
}
|
||
|
||
if (base != NULL)
|
||
*base = ret->vma;
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Helper function for `elf_get_probes', which gathers information about all
|
||
SystemTap probes from OBJFILE. */
|
||
|
||
static void
|
||
stap_get_probes (VEC (probe_p) **probesp, struct objfile *objfile)
|
||
{
|
||
/* If we are here, then this is the first time we are parsing the
|
||
SystemTap probe's information. We basically have to count how many
|
||
probes the objfile has, and then fill in the necessary information
|
||
for each one. */
|
||
bfd *obfd = objfile->obfd;
|
||
bfd_vma base;
|
||
struct sdt_note *iter;
|
||
unsigned save_probesp_len = VEC_length (probe_p, *probesp);
|
||
|
||
if (objfile->separate_debug_objfile_backlink != NULL)
|
||
{
|
||
/* This is a .debug file, not the objfile itself. */
|
||
return;
|
||
}
|
||
|
||
if (elf_tdata (obfd)->sdt_note_head == NULL)
|
||
{
|
||
/* There isn't any probe here. */
|
||
return;
|
||
}
|
||
|
||
if (!get_stap_base_address (obfd, &base))
|
||
{
|
||
/* There was an error finding the base address for the section.
|
||
Just return NULL. */
|
||
return;
|
||
}
|
||
|
||
/* Parsing each probe's information. */
|
||
for (iter = elf_tdata (obfd)->sdt_note_head;
|
||
iter != NULL;
|
||
iter = iter->next)
|
||
{
|
||
/* We first have to handle all the information about the
|
||
probe which is present in the section. */
|
||
handle_stap_probe (objfile, iter, probesp, base);
|
||
}
|
||
|
||
if (save_probesp_len == VEC_length (probe_p, *probesp))
|
||
{
|
||
/* If we are here, it means we have failed to parse every known
|
||
probe. */
|
||
complaint (&symfile_complaints, _("could not parse SystemTap probe(s) "
|
||
"from inferior"));
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* Implementation of the type_name method. */
|
||
|
||
static const char *
|
||
stap_type_name (struct probe *probe)
|
||
{
|
||
gdb_assert (probe->pops == &stap_probe_ops);
|
||
return "stap";
|
||
}
|
||
|
||
static int
|
||
stap_probe_is_linespec (const char **linespecp)
|
||
{
|
||
static const char *const keywords[] = { "-pstap", "-probe-stap", NULL };
|
||
|
||
return probe_is_linespec_by_keyword (linespecp, keywords);
|
||
}
|
||
|
||
static void
|
||
stap_gen_info_probes_table_header (VEC (info_probe_column_s) **heads)
|
||
{
|
||
info_probe_column_s stap_probe_column;
|
||
|
||
stap_probe_column.field_name = "semaphore";
|
||
stap_probe_column.print_name = _("Semaphore");
|
||
|
||
VEC_safe_push (info_probe_column_s, *heads, &stap_probe_column);
|
||
}
|
||
|
||
static void
|
||
stap_gen_info_probes_table_values (struct probe *probe_generic,
|
||
VEC (const_char_ptr) **ret)
|
||
{
|
||
struct stap_probe *probe = (struct stap_probe *) probe_generic;
|
||
struct gdbarch *gdbarch;
|
||
const char *val = NULL;
|
||
|
||
gdb_assert (probe_generic->pops == &stap_probe_ops);
|
||
|
||
gdbarch = probe->p.arch;
|
||
|
||
if (probe->sem_addr != 0)
|
||
val = print_core_address (gdbarch, probe->sem_addr);
|
||
|
||
VEC_safe_push (const_char_ptr, *ret, val);
|
||
}
|
||
|
||
/* SystemTap probe_ops. */
|
||
|
||
const struct probe_ops stap_probe_ops =
|
||
{
|
||
stap_probe_is_linespec,
|
||
stap_get_probes,
|
||
stap_get_probe_address,
|
||
stap_get_probe_argument_count,
|
||
stap_can_evaluate_probe_arguments,
|
||
stap_evaluate_probe_argument,
|
||
stap_compile_to_ax,
|
||
stap_set_semaphore,
|
||
stap_clear_semaphore,
|
||
stap_probe_destroy,
|
||
stap_type_name,
|
||
stap_gen_info_probes_table_header,
|
||
stap_gen_info_probes_table_values,
|
||
NULL, /* enable_probe */
|
||
NULL /* disable_probe */
|
||
};
|
||
|
||
/* Implementation of the `info probes stap' command. */
|
||
|
||
static void
|
||
info_probes_stap_command (char *arg, int from_tty)
|
||
{
|
||
info_probes_for_ops (arg, from_tty, &stap_probe_ops);
|
||
}
|
||
|
||
void _initialize_stap_probe (void);
|
||
|
||
void
|
||
_initialize_stap_probe (void)
|
||
{
|
||
VEC_safe_push (probe_ops_cp, all_probe_ops, &stap_probe_ops);
|
||
|
||
add_setshow_zuinteger_cmd ("stap-expression", class_maintenance,
|
||
&stap_expression_debug,
|
||
_("Set SystemTap expression debugging."),
|
||
_("Show SystemTap expression debugging."),
|
||
_("When non-zero, the internal representation "
|
||
"of SystemTap expressions will be printed."),
|
||
NULL,
|
||
show_stapexpressiondebug,
|
||
&setdebuglist, &showdebuglist);
|
||
|
||
add_cmd ("stap", class_info, info_probes_stap_command,
|
||
_("\
|
||
Show information about SystemTap static probes.\n\
|
||
Usage: info probes stap [PROVIDER [NAME [OBJECT]]]\n\
|
||
Each argument is a regular expression, used to select probes.\n\
|
||
PROVIDER matches probe provider names.\n\
|
||
NAME matches the probe names.\n\
|
||
OBJECT matches the executable or shared library name."),
|
||
info_probes_cmdlist_get ());
|
||
|
||
}
|