gdb/location.h

/* Data structures and API for event locations in GDB.
   Copyright (C) 2013-2017 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef LOCATIONS_H
#define LOCATIONS_H 1

struct language_defn;
struct event_location;

/* An enumeration of possible signs for a line offset.  */

enum offset_relative_sign
{
  /* No sign  */
  LINE_OFFSET_NONE,

  /* A plus sign ("+")  */
  LINE_OFFSET_PLUS,

  /* A minus sign ("-")  */
  LINE_OFFSET_MINUS,

  /* A special "sign" for unspecified offset.  */
  LINE_OFFSET_UNKNOWN
};

/* A line offset in a location.  */

struct line_offset
{
  /* Line offset and any specified sign.  */
  int offset;
  enum offset_relative_sign sign;
};

/* An enumeration of the various ways to specify a stop event
   location (used with create_breakpoint).  */

enum event_location_type
{
  /* A traditional linespec.  */
  LINESPEC_LOCATION,

  /* An address in the inferior.  */
  ADDRESS_LOCATION,

  /* An explicit location.  */
  EXPLICIT_LOCATION,

  /* A probe location.  */
  PROBE_LOCATION
};

/* An explicit location.  This structure is used to bypass the
   parsing done on linespecs.  It still has the same requirements
   as linespecs, though.  For example, source_filename requires
   at least one other field.  */

struct explicit_location
{
  /* The source filename. Malloc'd.  */
  char *source_filename;

  /* The function name.  Malloc'd.  */
  char *function_name;

  /* The name of a label.  Malloc'd.  */
  char *label_name;

  /* A line offset relative to the start of the symbol
     identified by the above fields or the current symtab
     if the other fields are NULL.  */
  struct line_offset line_offset;
};

/* Return the type of the given event location.  */

extern enum event_location_type
  event_location_type (const struct event_location *);

/* Return a malloc'd explicit string representation of the given
   explicit location.  The location must already be canonicalized/valid.  */

extern char *
  explicit_location_to_string (const struct explicit_location *explicit_loc);

/* Return a malloc'd linespec string representation of the given
   explicit location.  The location must already be canonicalized/valid.  */

extern char *
  explicit_location_to_linespec (const struct explicit_location *explicit_loc);

/* Return a string representation of the LOCATION.
   This function may return NULL for unspecified linespecs,
   e.g, LOCATION_LINESPEC and addr_string is NULL.

   The result is cached in LOCATION.  */

extern const char *
  event_location_to_string (struct event_location *location);

/* A deleter for a struct event_location.  */

struct event_location_deleter
{
  void operator() (event_location *location) const;
};

/* A unique pointer for event_location.  */
typedef std::unique_ptr<event_location, event_location_deleter>
     event_location_up;

/* Create a new linespec location.  */

extern event_location_up new_linespec_location (char **linespec);

/* Return the linespec location (a string) of the given event_location
   (which must be of type LINESPEC_LOCATION).  */

extern const char *
  get_linespec_location (const struct event_location *location);

/* Create a new address location.
   ADDR is the address corresponding to this event_location.
   ADDR_STRING, a string of ADDR_STRING_LEN characters, is
   the expression that was parsed to determine the address ADDR.  */

extern event_location_up new_address_location (CORE_ADDR addr,
					       const char *addr_string,
					       int addr_string_len);

/* Return the address location (a CORE_ADDR) of the given event_location
   (which must be of type ADDRESS_LOCATION).  */

extern CORE_ADDR
  get_address_location (const struct event_location *location);

/* Return the expression (a string) that was used to compute the address
   of the given event_location (which must be of type ADDRESS_LOCATION).  */

extern const char *
  get_address_string_location (const struct event_location *location);

/* Create a new probe location.  */

extern event_location_up new_probe_location (const char *probe);

/* Return the probe location (a string) of the given event_location
   (which must be of type PROBE_LOCATION).  */

extern const char *
  get_probe_location (const struct event_location *location);

/* Initialize the given explicit location.  */

extern void
  initialize_explicit_location (struct explicit_location *explicit_loc);

/* Create a new explicit location.  If not NULL, EXPLICIT is checked for
   validity.  If invalid, an exception is thrown.  */

extern event_location_up
  new_explicit_location (const struct explicit_location *explicit_loc);

/* Return the explicit location of the given event_location
   (which must be of type EXPLICIT_LOCATION).  */

extern struct explicit_location *
  get_explicit_location (struct event_location *location);

/* A const version of the above.  */

extern const struct explicit_location *
  get_explicit_location_const (const struct event_location *location);

/* Return a copy of the given SRC location.  */

extern event_location_up
  copy_event_location (const struct event_location *src);

/* Attempt to convert the input string in *ARGP into an event_location.
   ARGP is advanced past any processed input.  Returns an event_location
   (malloc'd) if an event location was successfully found in *ARGP,
   NULL otherwise.

   This function may call error() if *ARGP looks like properly formed,
   but invalid, input, e.g., if it is called with missing argument parameters
   or invalid options.

   This function is intended to be used by CLI commands and will parse
   explicit locations in a CLI-centric way.  Other interfaces should use
   string_to_event_location_basic if they want to maintain support for
   legacy specifications of probe, address, and linespec locations.  */

extern event_location_up
  string_to_event_location (char **argp,
			    const struct language_defn *langauge);

/* Like string_to_event_location, but does not attempt to parse explicit
   locations.  */

extern event_location_up
  string_to_event_location_basic (char **argp,
				  const struct language_defn *language);

/* Structure filled in by string_to_explicit_location to aid the
   completer.  */
struct explicit_completion_info
{
  /* Pointer to the last option found.  E.g., in "b -sou src.c -fun
     func", LAST_OPTION is left pointing at "-fun func".  */
  const char *last_option = NULL;

  /* These point to the start and end of a quoted argument, iff the
     last argument was quoted.  If parsing finds an incomplete quoted
     string (e.g., "break -function 'fun"), then QUOTED_ARG_START is
     set to point to the opening \', and QUOTED_ARG_END is left NULL.
     If the last option is not quoted, then both are set to NULL. */
  const char *quoted_arg_start = NULL;
  const char *quoted_arg_end = NULL;
};

/* Attempt to convert the input string in *ARGP into an explicit location.
   ARGP is advanced past any processed input.  Returns an event_location
   (malloc'd) if an explicit location was successfully found in *ARGP,
   NULL otherwise.

   If COMPLETION_INFO is NULL, this function may call error() if *ARGP
   looks like improperly formed input, e.g., if it is called with
   missing argument parameters or invalid options.  If COMPLETION_INFO
   is not NULL, this function will not throw any exceptions.  */

extern event_location_up
  string_to_explicit_location (const char **argp,
			       const struct language_defn *language,
			       explicit_completion_info *completion_info);

/* A convenience function for testing for unset locations.  */

extern int event_location_empty_p (const struct event_location *location);

/* Set the location's string representation.  If STRING is NULL, clear
   the string representation.  */

extern void
  set_event_location_string (struct event_location *location,
			     const char *string);
#endif /* LOCATIONS_H */