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     /* Return 1 if the probe interface can evaluate the arguments of probe
  77        PROBE, zero otherwise.  See the comments on
  78        sym_probe_fns:can_evaluate_probe_arguments for more details.  */
  79
  80     int (*can_evaluate_probe_arguments) (struct probe *probe);
  81
  82     /* Evaluate the Nth argument from the PROBE, returning a value
  83        corresponding to it.  The argument number is represented N.  */
  84
  85     struct value *(*evaluate_probe_argument) (struct probe *probe,
  86                                               unsigned n);
  87
  88     /* Compile the Nth argument of the PROBE to an agent expression.
  89        The argument number is represented by N.  */
  90
  91     void (*compile_to_ax) (struct probe *probe, struct agent_expr *aexpr,
  92                            struct axs_value *axs_value, unsigned n);
  93
  94     /* Set the semaphore associated with the PROBE.  This function only makes
  95        sense if the probe has a concept of semaphore associated to a
  96        probe.  */
  97
  98     void (*set_semaphore) (struct probe *probe, struct gdbarch *gdbarch);
  99
 100     /* Clear the semaphore associated with the PROBE.  This function only
 101        makes sense if the probe has a concept of semaphore associated to
 102        a probe.  */
 103
 104     void (*clear_semaphore) (struct probe *probe, struct gdbarch *gdbarch);
 105
 106     /* Function called to destroy PROBE's specific data.  This function
 107        shall not free PROBE itself.  */
 108
 109     void (*destroy) (struct probe *probe);
 110
 111     /* Function responsible for providing the extra fields that will be
 112        printed in the `info probes' command.  It should fill HEADS
 113        with whatever extra fields it needs.  If the backend doesn't need
 114        to print extra fields, it can set this method to NULL.  */
 115
 116     void (*gen_info_probes_table_header) (VEC (info_probe_column_s) **heads);
 117
 118     /* Function that will fill VALUES with the values of the extra fields
 119        to be printed for PROBE.  If the backend implements the
 120        `gen_ui_out_table_header' method, then it should implement
 121        this method as well.  The backend should also guarantee that the
 122        order and the number of values in the vector is exactly the same
 123        as the order of the extra fields provided in the method
 124        `gen_ui_out_table_header'.  If a certain field is to be skipped
 125        when printing the information, you can push a NULL value in that
 126        position in the vector.  */
 127
 128     void (*gen_info_probes_table_values) (struct probe *probe,
 129                                           VEC (const_char_ptr) **values);
 130   };
 131
 132 /* Definition of a vector of probe_ops.  */
 133
 134 typedef const struct probe_ops *probe_ops_cp;
 135 DEF_VEC_P (probe_ops_cp);
 136 extern VEC (probe_ops_cp) *all_probe_ops;
 137
 138 /* The probe_ops associated with the generic probe.  */
 139
 140 extern const struct probe_ops probe_ops_any;
 141
 142 /* Helper function that, given KEYWORDS, iterate over it trying to match
 143    each keyword with LINESPECP.  If it succeeds, it updates the LINESPECP
 144    pointer and returns 1.  Otherwise, nothing is done to LINESPECP and zero
 145    is returned.  */
 146
 147 extern int probe_is_linespec_by_keyword (const char **linespecp,
 148                                          const char *const *keywords);
 149
 150 /* Return specific PROBE_OPS * matching *LINESPECP and possibly updating
 151    *LINESPECP to skip its "-probe-type " prefix.  Return &probe_ops_any if
 152    *LINESPECP matches "-probe ", that is any unspecific probe.  Return NULL if
 153    *LINESPECP is not identified as any known probe type, *LINESPECP is not
 154    modified in such case.  */
 155
 156 extern const struct probe_ops *probe_linespec_to_ops (const char **linespecp);
 157
 158 /* The probe itself.  The struct contains generic information about the
 159    probe, and then some specific information which should be stored in
 160    the `probe_info' field.  */
 161
 162 struct probe
 163   {
 164     /* The operations associated with this probe.  */
 165     const struct probe_ops *pops;
 166
 167     /* The objfile which contains this probe.  Even if the probe is also
 168        present in a separate debug objfile, this variable always points to
 169        the non-separate debug objfile.  */
 170     struct objfile *objfile;
 171
 172     /* The name of the probe.  */
 173     const char *name;
 174
 175     /* The provider of the probe.  It generally defaults to the name of
 176        the objfile which contains the probe.  */
 177     const char *provider;
 178
 179     /* The address where the probe is inserted.  */
 180     CORE_ADDR address;
 181   };
 182
 183 /* A helper for linespec that decodes a probe specification.  It returns a
 184    symtabs_and_lines object and updates *ARGPTR or throws an error.  The
 185    argument PTYPE specifies the type of the probe(s) to be parsed.  */
 186
 187 extern struct symtabs_and_lines parse_probes (char **argptr,
 188                                               struct linespec_result *canon);
 189
 190 /* Helper function to register the proper probe_ops to a newly created probe.
 191    This function is mainly called from `sym_get_probes'.  */
 192
 193 extern void register_probe_ops (struct probe *probe);
 194
 195 /* Given a PC, find an associated probe with type PTYPE.  If a probe is
 196    found, return it.  If no probe is found, return NULL.  */
 197
 198 extern struct probe *find_probe_by_pc (CORE_ADDR pc);
 199
 200 /* Search OBJFILE for a probe with the given PROVIDER, NAME and PTYPE.
 201    Return a VEC of all probes that were found.  If no matching probe
 202    is found, return NULL.  The caller must free the VEC.  */
 203
 204 extern VEC (probe_p) *find_probes_in_objfile (struct objfile *objfile,
 205                                               const char *provider,
 206                                               const char *name);
 207
 208 /* Generate a `info probes' command output for probe_ops represented by
 209    POPS.  If POPS is NULL it considers any probes types.  It is a helper
 210    function that can be used by the probe backends to print their
 211    `info probe TYPE'.  */
 212
 213 extern void info_probes_for_ops (char *arg, int from_tty,
 214                                  const struct probe_ops *pops);
 215
 216 /* Return the `cmd_list_element' associated with the `info probes' command,
 217    or create a new one if it doesn't exist.  Helper function that serves the
 218    purpose of avoiding the case of a backend using the `cmd_list_element'
 219    associated with `info probes', without having it registered yet.  */
 220
 221 extern struct cmd_list_element **info_probes_cmdlist_get (void);
 222
 223 /* Return the argument count of the specified probe.  */
 224
 225 extern unsigned get_probe_argument_count (struct probe *probe);
 226
 227 /* Return 1 if the probe interface associated with PROBE can evaluate
 228    arguments, zero otherwise.  See the comments on the definition of
 229    sym_probe_fns:can_evaluate_probe_arguments for more details.  */
 230
 231 extern int can_evaluate_probe_arguments (struct probe *probe);
 232
 233 /* Evaluate argument N of the specified probe.  N must be between 0
 234    inclusive and get_probe_argument_count exclusive.  */
 235
 236 extern struct value *evaluate_probe_argument (struct probe *probe,
 237                                               unsigned n);
 238
 239 /* A convenience function that finds a probe at the PC in FRAME and
 240    evaluates argument N, with 0 <= N < number_of_args.  If there is no
 241    probe at that location, or if the probe does not have enough arguments,
 242    this returns NULL.  */
 243
 244 extern struct value *probe_safe_evaluate_at_pc (struct frame_info *frame,
 245                                                 unsigned n);
 246
 247 #endif /* !defined (PROBE_H) */