gdb/probe.h

   1 /* Generic SDT probe support for GDB.
   2
   3    Copyright (C) 2012-2013 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 #if !defined (PROBE_H)
  21 #define PROBE_H 1
  22
  23 #include "gdb_vecs.h"
  24
  25 /* Definition of a vector of probes.  */
  26
  27 typedef struct probe *probe_p;
  28 DEF_VEC_P (probe_p);
  29
  30 struct linespec_result;
  31
  32 /* Structure useful for passing the header names in the method
  33    `gen_ui_out_table_header'.  */
  34
  35 struct info_probe_column
  36   {
  37     /* The internal name of the field.  This string cannot be capitalized nor
  38        localized, e.g., "extra_field".  */
  39
  40     const char *field_name;
  41
  42     /* The field name to be printed in the `info probes' command.  This
  43        string can be capitalized and localized, e.g., _("Extra Field").  */
  44     const char *print_name;
  45   };
  46
  47 typedef struct info_probe_column info_probe_column_s;
  48 DEF_VEC_O (info_probe_column_s);
  49
  50 /* Operations associated with a probe.  */
  51
  52 struct probe_ops
  53   {
  54     /* Method responsible for verifying if LINESPECP is a valid linespec for
  55        a probe breakpoint.  It should return 1 if it is, or zero if it is not.
  56        It also should update LINESPECP in order to discard the breakpoint
  57        option associated with this linespec.  For example, if the option is
  58        `-probe', and the LINESPECP is `-probe abc', the function should
  59        return 1 and set LINESPECP to `abc'.  */
  60
  61     int (*is_linespec) (const char **linespecp);
  62
  63     /* Function that should fill PROBES with known probes from OBJFILE.  */
  64
  65     void (*get_probes) (VEC (probe_p) **probes, struct objfile *objfile);
  66
  67     /* Function used to relocate addresses from PROBE according to some DELTA
  68        provided.  */
  69
  70     void (*relocate) (struct probe *probe, CORE_ADDR delta);
  71
  72     /* Return the number of arguments of PROBE.  */
  73
  74     unsigned (*get_probe_argument_count) (struct probe *probe);
  75
  76     /* Evaluate the Nth argument from the PROBE, returning a value
  77        corresponding to it.  The argument number is represented N.  */
  78
  79     struct value *(*evaluate_probe_argument) (struct probe *probe,
  80                                               unsigned n);
  81
  82     /* Compile the Nth argument of the PROBE to an agent expression.
  83        The argument number is represented by N.  */
  84
  85     void (*compile_to_ax) (struct probe *probe, struct agent_expr *aexpr,
  86                            struct axs_value *axs_value, unsigned n);
  87
  88     /* Set the semaphore associated with the PROBE.  This function only makes
  89        sense if the probe has a concept of semaphore associated to a
  90        probe.  */
  91
  92     void (*set_semaphore) (struct probe *probe, struct gdbarch *gdbarch);
  93
  94     /* Clear the semaphore associated with the PROBE.  This function only
  95        makes sense if the probe has a concept of semaphore associated to
  96        a probe.  */
  97
  98     void (*clear_semaphore) (struct probe *probe, struct gdbarch *gdbarch);
  99
 100     /* Function called to destroy PROBE's specific data.  This function
 101        shall not free PROBE itself.  */
 102
 103     void (*destroy) (struct probe *probe);
 104
 105     /* Function responsible for providing the extra fields that will be
 106        printed in the `info probes' command.  It should fill HEADS
 107        with whatever extra fields it needs.  If the backend doesn't need
 108        to print extra fields, it can set this method to NULL.  */
 109
 110     void (*gen_info_probes_table_header) (VEC (info_probe_column_s) **heads);
 111
 112     /* Function that will fill VALUES with the values of the extra fields
 113        to be printed for PROBE.  If the backend implements the
 114        `gen_ui_out_table_header' method, then it should implement
 115        this method as well.  The backend should also guarantee that the
 116        order and the number of values in the vector is exactly the same
 117        as the order of the extra fields provided in the method
 118        `gen_ui_out_table_header'.  If a certain field is to be skipped
 119        when printing the information, you can push a NULL value in that
 120        position in the vector.  */
 121
 122     void (*gen_info_probes_table_values) (struct probe *probe,
 123                                           VEC (const_char_ptr) **values);
 124   };
 125
 126 /* Definition of a vector of probe_ops.  */
 127
 128 typedef const struct probe_ops *probe_ops_cp;
 129 DEF_VEC_P (probe_ops_cp);
 130 extern VEC (probe_ops_cp) *all_probe_ops;
 131
 132 /* The probe_ops associated with the generic probe.  */
 133
 134 extern const struct probe_ops probe_ops_any;
 135
 136 /* Helper function that, given KEYWORDS, iterate over it trying to match
 137    each keyword with LINESPECP.  If it succeeds, it updates the LINESPECP
 138    pointer and returns 1.  Otherwise, nothing is done to LINESPECP and zero
 139    is returned.  */
 140
 141 extern int probe_is_linespec_by_keyword (const char **linespecp,
 142                                          const char *const *keywords);
 143
 144 /* Return specific PROBE_OPS * matching *LINESPECP and possibly updating
 145    *LINESPECP to skip its "-probe-type " prefix.  Return &probe_ops_any if
 146    *LINESPECP matches "-probe ", that is any unspecific probe.  Return NULL if
 147    *LINESPECP is not identified as any known probe type, *LINESPECP is not
 148    modified in such case.  */
 149
 150 extern const struct probe_ops *probe_linespec_to_ops (const char **linespecp);
 151
 152 /* The probe itself.  The struct contains generic information about the
 153    probe, and then some specific information which should be stored in
 154    the `probe_info' field.  */
 155
 156 struct probe
 157   {
 158     /* The operations associated with this probe.  */
 159     const struct probe_ops *pops;
 160
 161     /* The objfile which contains this probe.  Even if the probe is also
 162        present in a separate debug objfile, this variable always points to
 163        the non-separate debug objfile.  */
 164     struct objfile *objfile;
 165
 166     /* The name of the probe.  */
 167     const char *name;
 168
 169     /* The provider of the probe.  It generally defaults to the name of
 170        the objfile which contains the probe.  */
 171     const char *provider;
 172
 173     /* The address where the probe is inserted.  */
 174     CORE_ADDR address;
 175   };
 176
 177 /* A helper for linespec that decodes a probe specification.  It returns a
 178    symtabs_and_lines object and updates *ARGPTR or throws an error.  The
 179    argument PTYPE specifies the type of the probe(s) to be parsed.  */
 180
 181 extern struct symtabs_and_lines parse_probes (char **argptr,
 182                                               struct linespec_result *canon);
 183
 184 /* Helper function to register the proper probe_ops to a newly created probe.
 185    This function is mainly called from `sym_get_probes'.  */
 186
 187 extern void register_probe_ops (struct probe *probe);
 188
 189 /* Given a PC, find an associated probe with type PTYPE.  If a probe is
 190    found, return it.  If no probe is found, return NULL.  */
 191
 192 extern struct probe *find_probe_by_pc (CORE_ADDR pc);
 193
 194 /* Search OBJFILE for a probe with the given PROVIDER, NAME and PTYPE.
 195    Return a VEC of all probes that were found.  If no matching probe
 196    is found, return NULL.  The caller must free the VEC.  */
 197
 198 extern VEC (probe_p) *find_probes_in_objfile (struct objfile *objfile,
 199                                               const char *provider,
 200                                               const char *name);
 201
 202 /* Generate a `info probes' command output for probe_ops represented by
 203    POPS.  If POPS is NULL it considers any probes types.  It is a helper
 204    function that can be used by the probe backends to print their
 205    `info probe TYPE'.  */
 206
 207 extern void info_probes_for_ops (char *arg, int from_tty,
 208                                  const struct probe_ops *pops);
 209
 210 /* Return the `cmd_list_element' associated with the `info probes' command,
 211    or create a new one if it doesn't exist.  Helper function that serves the
 212    purpose of avoiding the case of a backend using the `cmd_list_element'
 213    associated with `info probes', without having it registered yet.  */
 214
 215 extern struct cmd_list_element **info_probes_cmdlist_get (void);
 216
 217 /* A convenience function that finds a probe at the PC in FRAME and
 218    evaluates argument N, with 0 <= N < number_of_args.  If there is no
 219    probe at that location, or if the probe does not have enough arguments,
 220    this returns NULL.  */
 221
 222 extern struct value *probe_safe_evaluate_at_pc (struct frame_info *frame,
 223                                                 unsigned n);
 224
 225 #endif /* !defined (PROBE_H) */