| 1 | /* Generic SDT probe support for GDB. |
| 2 | |
| 3 | Copyright (C) 2012-2020 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 "symtab.h" |
| 24 | |
| 25 | struct event_location; |
| 26 | struct linespec_result; |
| 27 | |
| 28 | /* Structure useful for passing the header names in the method |
| 29 | `gen_ui_out_table_header'. */ |
| 30 | |
| 31 | struct info_probe_column |
| 32 | { |
| 33 | /* The internal name of the field. This string cannot be capitalized nor |
| 34 | localized, e.g., "extra_field". */ |
| 35 | const char *field_name; |
| 36 | |
| 37 | /* The field name to be printed in the `info probes' command. This |
| 38 | string can be capitalized and localized, e.g., _("Extra Field"). */ |
| 39 | const char *print_name; |
| 40 | }; |
| 41 | |
| 42 | /* Operations that act on probes, but are specific to each backend. |
| 43 | These methods do not go into the 'class probe' because they do not |
| 44 | act on a single probe; instead, they are used to operate on many |
| 45 | probes at once, or to provide information about the probe backend |
| 46 | itself, instead of a single probe. |
| 47 | |
| 48 | Each probe backend needs to inherit this class and implement all of |
| 49 | the virtual functions specified here. Then, an object shall be |
| 50 | instantiated and added (or "registered") to the |
| 51 | ALL_STATIC_PROBE_OPS vector so that the frontend probe interface |
| 52 | can use it in the generic probe functions. */ |
| 53 | |
| 54 | class static_probe_ops |
| 55 | { |
| 56 | public: |
| 57 | /* Method responsible for verifying if LINESPECP is a valid linespec |
| 58 | for a probe breakpoint. It should return true if it is, or false |
| 59 | if it is not. It also should update LINESPECP in order to |
| 60 | discard the breakpoint option associated with this linespec. For |
| 61 | example, if the option is `-probe', and the LINESPECP is `-probe |
| 62 | abc', the function should return 1 and set LINESPECP to |
| 63 | `abc'. */ |
| 64 | virtual bool is_linespec (const char **linespecp) const = 0; |
| 65 | |
| 66 | /* Function that should fill PROBES with known probes from OBJFILE. */ |
| 67 | virtual void get_probes (std::vector<std::unique_ptr<probe>> *probes, |
| 68 | struct objfile *objfile) const = 0; |
| 69 | |
| 70 | /* Return a pointer to a name identifying the probe type. This is |
| 71 | the string that will be displayed in the "Type" column of the |
| 72 | `info probes' command. */ |
| 73 | virtual const char *type_name () const = 0; |
| 74 | |
| 75 | /* Return true if the probe can be enabled; false otherwise. */ |
| 76 | virtual bool can_enable () const |
| 77 | { |
| 78 | return false; |
| 79 | } |
| 80 | |
| 81 | /* Function responsible for providing the extra fields that will be |
| 82 | printed in the `info probes' command. It should fill HEADS |
| 83 | with whatever extra fields it needs. If no extra fields are |
| 84 | required by the probe backend, the method EMIT_INFO_PROBES_FIELDS |
| 85 | should return false. */ |
| 86 | virtual std::vector<struct info_probe_column> |
| 87 | gen_info_probes_table_header () const = 0; |
| 88 | }; |
| 89 | |
| 90 | /* Definition of a vector of static_probe_ops. */ |
| 91 | |
| 92 | extern std::vector<const static_probe_ops *> all_static_probe_ops; |
| 93 | |
| 94 | /* Helper function that, given KEYWORDS, iterate over it trying to match |
| 95 | each keyword with LINESPECP. If it succeeds, it updates the LINESPECP |
| 96 | pointer and returns 1. Otherwise, nothing is done to LINESPECP and zero |
| 97 | is returned. */ |
| 98 | |
| 99 | extern int probe_is_linespec_by_keyword (const char **linespecp, |
| 100 | const char *const *keywords); |
| 101 | |
| 102 | /* Return specific STATIC_PROBE_OPS * matching *LINESPECP and possibly |
| 103 | updating LINESPECP to skip its "-probe-type " prefix. Return |
| 104 | &static_probe_ops_any if LINESPECP matches "-probe ", that is any |
| 105 | unspecific probe. Return NULL if LINESPECP is not identified as |
| 106 | any known probe type, *LINESPECP is not modified in such case. */ |
| 107 | |
| 108 | extern const static_probe_ops * |
| 109 | probe_linespec_to_static_ops (const char **linespecp); |
| 110 | |
| 111 | /* The probe itself. The class contains generic information about the |
| 112 | probe. */ |
| 113 | |
| 114 | class probe |
| 115 | { |
| 116 | public: |
| 117 | /* Default constructor for a probe. */ |
| 118 | probe (std::string &&name_, std::string &&provider_, CORE_ADDR address_, |
| 119 | struct gdbarch *arch_) |
| 120 | : m_name (std::move (name_)), m_provider (std::move (provider_)), |
| 121 | m_address (address_), m_arch (arch_) |
| 122 | {} |
| 123 | |
| 124 | /* Virtual destructor. */ |
| 125 | virtual ~probe () |
| 126 | {} |
| 127 | |
| 128 | /* Compute the probe's relocated address. OBJFILE is the objfile |
| 129 | in which the probe originated. */ |
| 130 | virtual CORE_ADDR get_relocated_address (struct objfile *objfile) = 0; |
| 131 | |
| 132 | /* Return the number of arguments of the probe. This function can |
| 133 | throw an exception. */ |
| 134 | virtual unsigned get_argument_count (struct gdbarch *gdbarch) = 0; |
| 135 | |
| 136 | /* Return 1 if the probe interface can evaluate the arguments of |
| 137 | probe, zero otherwise. See the comments on |
| 138 | sym_probe_fns:can_evaluate_probe_arguments for more |
| 139 | details. */ |
| 140 | virtual bool can_evaluate_arguments () const = 0; |
| 141 | |
| 142 | /* Evaluate the Nth argument from the probe, returning a value |
| 143 | corresponding to it. The argument number is represented N. |
| 144 | This function can throw an exception. */ |
| 145 | virtual struct value *evaluate_argument (unsigned n, |
| 146 | struct frame_info *frame) = 0; |
| 147 | |
| 148 | /* Compile the Nth argument of the probe to an agent expression. |
| 149 | The argument number is represented by N. */ |
| 150 | virtual void compile_to_ax (struct agent_expr *aexpr, |
| 151 | struct axs_value *axs_value, |
| 152 | unsigned n) = 0; |
| 153 | |
| 154 | /* Set the semaphore associated with the probe. This function only |
| 155 | makes sense if the probe has a concept of semaphore associated to |
| 156 | a probe. */ |
| 157 | virtual void set_semaphore (struct objfile *objfile, |
| 158 | struct gdbarch *gdbarch) |
| 159 | {} |
| 160 | |
| 161 | /* Clear the semaphore associated with the probe. This function |
| 162 | only makes sense if the probe has a concept of semaphore |
| 163 | associated to a probe. */ |
| 164 | virtual void clear_semaphore (struct objfile *objfile, |
| 165 | struct gdbarch *gdbarch) |
| 166 | {} |
| 167 | |
| 168 | /* Return the pointer to the static_probe_ops instance related to |
| 169 | the probe type. */ |
| 170 | virtual const static_probe_ops *get_static_ops () const = 0; |
| 171 | |
| 172 | /* Function that will fill VALUES with the values of the extra |
| 173 | fields to be printed for the probe. |
| 174 | |
| 175 | If the backend implements the `gen_ui_out_table_header' method, |
| 176 | then it should implement this method as well. The backend should |
| 177 | also guarantee that the order and the number of values in the |
| 178 | vector is exactly the same as the order of the extra fields |
| 179 | provided in the method `gen_ui_out_table_header'. If a certain |
| 180 | field is to be skipped when printing the information, you can |
| 181 | push a NULL value in that position in the vector. */ |
| 182 | virtual std::vector<const char *> gen_info_probes_table_values () const |
| 183 | { |
| 184 | return std::vector<const char *> (); |
| 185 | } |
| 186 | |
| 187 | /* Enable the probe. The semantics of "enabling" a probe depend on |
| 188 | the specific backend. This function can throw an exception. */ |
| 189 | virtual void enable () |
| 190 | {} |
| 191 | |
| 192 | /* Disable the probe. The semantics of "disabling" a probe depend |
| 193 | on the specific backend. This function can throw an |
| 194 | exception. */ |
| 195 | virtual void disable () |
| 196 | {} |
| 197 | |
| 198 | /* Getter for M_NAME. */ |
| 199 | const std::string &get_name () const |
| 200 | { |
| 201 | return m_name; |
| 202 | } |
| 203 | |
| 204 | /* Getter for M_PROVIDER. */ |
| 205 | const std::string &get_provider () const |
| 206 | { |
| 207 | return m_provider; |
| 208 | } |
| 209 | |
| 210 | /* Getter for M_ADDRESS. */ |
| 211 | CORE_ADDR get_address () const |
| 212 | { |
| 213 | return m_address; |
| 214 | } |
| 215 | |
| 216 | /* Getter for M_ARCH. */ |
| 217 | struct gdbarch *get_gdbarch () const |
| 218 | { |
| 219 | return m_arch; |
| 220 | } |
| 221 | |
| 222 | private: |
| 223 | /* The name of the probe. */ |
| 224 | std::string m_name; |
| 225 | |
| 226 | /* The provider of the probe. It generally defaults to the name of |
| 227 | the objfile which contains the probe. */ |
| 228 | std::string m_provider; |
| 229 | |
| 230 | /* The address where the probe is inserted, relative to |
| 231 | SECT_OFF_TEXT. */ |
| 232 | CORE_ADDR m_address; |
| 233 | |
| 234 | /* The probe's architecture. */ |
| 235 | struct gdbarch *m_arch; |
| 236 | }; |
| 237 | |
| 238 | /* A bound probe holds a pointer to a probe and a pointer to the |
| 239 | probe's defining objfile. This is needed because probes are |
| 240 | independent of the program space and thus require relocation at |
| 241 | their point of use. */ |
| 242 | |
| 243 | struct bound_probe |
| 244 | { |
| 245 | /* Create an empty bound_probe object. */ |
| 246 | bound_probe () |
| 247 | {} |
| 248 | |
| 249 | /* Create and initialize a bound_probe object using PROBE and OBJFILE. */ |
| 250 | bound_probe (probe *probe_, struct objfile *objfile_) |
| 251 | : prob (probe_), objfile (objfile_) |
| 252 | {} |
| 253 | |
| 254 | /* The probe. */ |
| 255 | probe *prob = NULL; |
| 256 | |
| 257 | /* The objfile in which the probe originated. */ |
| 258 | struct objfile *objfile = NULL; |
| 259 | }; |
| 260 | |
| 261 | /* A helper for linespec that decodes a probe specification. It |
| 262 | returns a std::vector<symtab_and_line> object and updates LOC or |
| 263 | throws an error. */ |
| 264 | |
| 265 | extern std::vector<symtab_and_line> parse_probes |
| 266 | (const struct event_location *loc, |
| 267 | struct program_space *pspace, |
| 268 | struct linespec_result *canon); |
| 269 | |
| 270 | /* Given a PC, find an associated probe. If a probe is found, return |
| 271 | it. If no probe is found, return a bound probe whose fields are |
| 272 | both NULL. */ |
| 273 | |
| 274 | extern struct bound_probe find_probe_by_pc (CORE_ADDR pc); |
| 275 | |
| 276 | /* Search OBJFILE for a probe with the given PROVIDER, NAME. Return a |
| 277 | vector of all probes that were found. If no matching probe is found, |
| 278 | return an empty vector. */ |
| 279 | |
| 280 | extern std::vector<probe *> find_probes_in_objfile (struct objfile *objfile, |
| 281 | const char *provider, |
| 282 | const char *name); |
| 283 | |
| 284 | /* Generate a `info probes' command output for probes associated with |
| 285 | SPOPS. If SPOPS is related to the "any probe" type, then all probe |
| 286 | types are considered. It is a helper function that can be used by |
| 287 | the probe backends to print their `info probe TYPE'. */ |
| 288 | |
| 289 | extern void info_probes_for_spops (const char *arg, int from_tty, |
| 290 | const static_probe_ops *spops); |
| 291 | |
| 292 | /* Return the `cmd_list_element' associated with the `info probes' command, |
| 293 | or create a new one if it doesn't exist. Helper function that serves the |
| 294 | purpose of avoiding the case of a backend using the `cmd_list_element' |
| 295 | associated with `info probes', without having it registered yet. */ |
| 296 | |
| 297 | extern struct cmd_list_element **info_probes_cmdlist_get (void); |
| 298 | |
| 299 | /* A convenience function that finds a probe at the PC in FRAME and |
| 300 | evaluates argument N, with 0 <= N < number_of_args. If there is no |
| 301 | probe at that location, or if the probe does not have enough arguments, |
| 302 | this returns NULL. */ |
| 303 | |
| 304 | extern struct value *probe_safe_evaluate_at_pc (struct frame_info *frame, |
| 305 | unsigned n); |
| 306 | |
| 307 | #endif /* !defined (PROBE_H) */ |