binutils-gdb/gdb/linespec.h
Pedro Alves c2f4122d5c Limit breakpoint re-set to the current program space
Currently, we always re-set all locations of all breakpoints.  This
commit makes us re-set only locations of the current program space.

If we loaded symbols to a program space (e.g., "file" command or some
shared library was loaded), GDB must run through all breakpoints and
determine if any new locations need to be added to the breakpoint.
However, there's no reason to recreate locations for _other_ program
spaces, as those haven't changed.

Similarly, when we create a new inferior, through e.g., a fork, GDB
must run through all breakpoints and determine if any new locations
need to be added to the breakpoint.  There's no reason to destroy the
locations of the parent inferior and other inferiors.  We know those
won't change.

In addition to being inneficient, resetting breakpoints of inferiors
that are currently running is problematic, because:

 - some targets can't read memory while the inferior is running.

 - the inferior might exit while we're re-setting its breakpoints,
   which may confuse prologue skipping.

I went through all the places where we call breakpoint_re_set, and it
seems to me that all can be changed to only re-set locations of the
current program space.

The patch that reversed threads order in "info threads" etc. happened
to make gdb.threads/fork-plus-thread.exp expose this problem when
testing on x86/-m32.  The problem was latent and masked out by chance
by the code-cache:

 https://sourceware.org/ml/gdb-patches/2016-01/msg00213.html

Tested on x86-64 F20, native (-m64/-m32) and extended-remote
gdbserver.

Fixes the regression discussed in the url above with --target_board=unix/-m32:

 -FAIL: gdb.threads/fork-plus-threads.exp: detach-on-fork=off: inferior 1 exited
 +PASS: gdb.threads/fork-plus-threads.exp: detach-on-fork=off: inferior 1 exited
 -FAIL: gdb.threads/fork-plus-threads.exp: detach-on-fork=off: no threads left (timeout)
 -FAIL: gdb.threads/fork-plus-threads.exp: detach-on-fork=off: only inferior 1 left (the program exited)
 +PASS: gdb.threads/fork-plus-threads.exp: detach-on-fork=off: no threads left
 +PASS: gdb.threads/fork-plus-threads.exp: detach-on-fork=off: only inferior 1 left

gdb/ChangeLog:
2016-01-19  Pedro Alves  <palves@redhat.com>

	* ax-gdb.c (agent_command_1): Adjust call to decode_line_full.
	* break-catch-throw.c (re_set_exception_catchpoint): Pass the
	current program space down to linespec decoding and breakpoint
	location updating.
	* breakpoint.c (parse_breakpoint_sals): Adjust calls to
	decode_line_full.
	(until_break_command): Adjust calls to decode_line_1.
	(base_breakpoint_decode_location, bkpt_decode_location): Add
	'search_pspace' parameter.  Pass it along.
	(bkpt_probe_create_sals_from_location): Adjust calls to
	parse_probes.
	(tracepoint_decode_location, tracepoint_probe_decode_location)
	(strace_marker_decode_location): Add 'search_pspace' parameter.
	Pass it along.
	(all_locations_are_pending): Rewrite to take a breakpoint and
	program space as arguments instead.
	(hoist_existing_locations): New function.
	(update_breakpoint_locations): Add 'filter_pspace' parameter.  Use
	hoist_existing_locations instead of always removing all locations,
	and adjust to all_locations_are_pending change.
	(location_to_sals): Add 'search_pspace' parameter.  Pass it along.
	Don't disable the breakpoint if there are other locations in
	another program space.
	(breakpoint_re_set_default): Adjust to pass down the current
	program space as filter program space.
	(decode_location_default): Add 'search_pspace' parameter and pass
	it along.
	(prepare_re_set_context): Don't switch program space here.
	(breakpoint_re_set): Use save_current_space_and_thread instead of
	save_current_program_space.
	* breakpoint.h (struct breakpoint_ops) <decode_location>: Add
	'search_pspace' parameter.
	(update_breakpoint_locations): Add 'filter_pspace' parameter.
	* cli/cli-cmds.c (edit_command, list_command): Adjust calls to
	decode_line_1.
	* elfread.c (elf_gnu_ifunc_resolver_return_stop): Pass the current
	program space as filter program space.
	* linespec.c (struct linespec_state) <search_pspace>: New field.
	(create_sals_line_offset, convert_explicit_location_to_sals)
	(parse_linespec): Pass the search program space down.
	(linespec_state_constructor): Add 'search_pspace' parameter.
	Store it.
	(linespec_parser_new): Add 'search_pspace' parameter and pass it
	along.
	(linespec_lex_to_end): Adjust.
	(decode_line_full, decode_line_1): Add 'search_pspace' parameter
	and pass it along.
	(decode_line_with_last_displayed): Adjust.
	(collect_symtabs_from_filename, symtabs_from_filename): New
	'search_pspace' parameter.  Use it.
	(find_function_symbols): Pass the search program space down.
	* linespec.h (decode_line_1, decode_line_full): Add
	'search_pspace' parameter.
	* probe.c (parse_probes_in_pspace): New function, factored out
	from ...
	(parse_probes): ... this.  Add 'search_pspace' parameter and use
	it.
	* probe.h (parse_probes): Add pspace' parameter.
	* python/python.c (gdbpy_decode_line): Adjust.
	* tracepoint.c (scope_info): Adjust.
2016-01-19 12:18:14 +00:00

195 lines
6.9 KiB
C

/* Header for GDB line completion.
Copyright (C) 2000-2016 Free Software Foundation, Inc.
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/>. */
#if !defined (LINESPEC_H)
#define LINESPEC_H 1
struct symtab;
#include "vec.h"
/* Flags to pass to decode_line_1 and decode_line_full. */
enum decode_line_flags
{
/* Set this flag if you want the resulting SALs to describe the
first line of indicated functions. */
DECODE_LINE_FUNFIRSTLINE = 1,
/* Set this flag if you want "list mode". In this mode, a
FILE:LINE linespec will always return a result, and such
linespecs will not be expanded to all matches. */
DECODE_LINE_LIST_MODE = 2
};
/* decode_line_full returns a vector of these. */
struct linespec_sals
{
/* This is the location corresponding to the sals contained in this
object. It can be passed as the FILTER argument to future calls
to decode_line_full. This is freed by
destroy_linespec_result. */
char *canonical;
/* Sals. The 'sals' field is destroyed by
destroy_linespec_result. */
struct symtabs_and_lines sals;
};
typedef struct linespec_sals linespec_sals;
DEF_VEC_O (linespec_sals);
/* An instance of this may be filled in by decode_line_1. The caller
must call init_linespec_result to initialize it and
destroy_linespec_result to destroy it. The caller must make copies
of any data that it needs to keep. */
struct linespec_result
{
/* If non-zero, the linespec should be displayed to the user. This
is used by "unusual" linespecs where the ordinary `info break'
display mechanism would do the wrong thing. */
int special_display;
/* If non-zero, the linespec result should be considered to be a
"pre-expanded" multi-location linespec. A pre-expanded linespec
holds all matching locations in a single linespec_sals
object. */
int pre_expanded;
/* If PRE_EXPANDED is non-zero, this is set to the location entered
by the user. This will be freed by destroy_linespec_result. */
struct event_location *location;
/* The sals. The vector will be freed by
destroy_linespec_result. */
VEC (linespec_sals) *sals;
};
/* Initialize a linespec_result. */
extern void init_linespec_result (struct linespec_result *);
/* Destroy a linespec_result. */
extern void destroy_linespec_result (struct linespec_result *);
/* Return a cleanup that destroys a linespec_result. */
extern struct cleanup *
make_cleanup_destroy_linespec_result (struct linespec_result *);
/* Decode a linespec using the provided default symtab and line. */
extern struct symtabs_and_lines
decode_line_1 (const struct event_location *location, int flags,
struct program_space *search_pspace,
struct symtab *default_symtab, int default_line);
/* Parse LOCATION and return results. This is the "full"
interface to this module, which handles multiple results
properly.
For FLAGS, see decode_line_flags. DECODE_LINE_LIST_MODE is not
valid for this function.
If SEARCH_PSPACE is not NULL, symbol search is restricted to just
that program space.
DEFAULT_SYMTAB and DEFAULT_LINE describe the default location.
DEFAULT_SYMTAB can be NULL, in which case the current symtab and
line are used.
CANONICAL is where the results are stored. It must not be NULL.
SELECT_MODE must be one of the multiple_symbols_* constants, or
NULL. It determines how multiple results will be handled. If
NULL, the appropriate CLI value will be used.
FILTER can either be NULL or a string holding a canonical name.
This is only valid when SELECT_MODE is multiple_symbols_all.
Multiple results are handled differently depending on the
arguments:
. With multiple_symbols_cancel, an exception is thrown.
. With multiple_symbols_ask, a menu is presented to the user. The
user may select none, in which case an exception is thrown; or all,
which is handled like multiple_symbols_all, below. Otherwise,
CANONICAL->SALS will have one entry for each name the user chose.
. With multiple_symbols_all, CANONICAL->SALS will have a single
entry describing all the matching locations. If FILTER is
non-NULL, then only locations whose canonical name is equal (in the
strcmp sense) to FILTER will be returned; all others will be
filtered out. */
extern void decode_line_full (const struct event_location *location, int flags,
struct program_space *search_pspace,
struct symtab *default_symtab, int default_line,
struct linespec_result *canonical,
const char *select_mode,
const char *filter);
/* Given a string, return the line specified by it, using the current
source symtab and line as defaults.
This is for commands like "list" and "breakpoint". */
extern struct symtabs_and_lines decode_line_with_current_source (char *, int);
/* Given a string, return the line specified by it, using the last displayed
codepoint's values as defaults, or nothing if they aren't valid. */
extern struct symtabs_and_lines decode_line_with_last_displayed (char *, int);
/* Does P represent one of the keywords? If so, return
the keyword. If not, return NULL. */
extern const char *linespec_lexer_lex_keyword (const char *p);
/* Parse a line offset from STRING. */
extern struct line_offset linespec_parse_line_offset (const char *string);
/* Return the quote characters permitted by the linespec parser. */
extern const char *get_gdb_linespec_parser_quote_characters (void);
/* Does STRING represent an Ada operator? If so, return the length
of the decoded operator name. If not, return 0. */
extern int is_ada_operator (const char *string);
/* Find an instance of the character C in the string S that is outside
of all parenthesis pairs, single-quoted strings, and double-quoted
strings. Also, ignore the char within a template name, like a ','
within foo<int, int>. */
extern const char *find_toplevel_char (const char *s, char c);
/* Find the end of the (first) linespec pointed to by *STRINGP.
STRINGP will be advanced to this point. */
extern void linespec_lex_to_end (char **stringp);
/* Evaluate the expression pointed to by EXP_PTR into a CORE_ADDR,
advancing EXP_PTR past any parsed text. */
extern CORE_ADDR linespec_expression_to_pc (const char **exp_ptr);
#endif /* defined (LINESPEC_H) */