old-cross-binutils/gdb/completer.h
Gary Benson ef0b411a11 Add max-completions parameter, and implement tab-completion limiting.
This commit adds a new exception, MAX_COMPLETIONS_REACHED_ERROR, to be
thrown whenever the completer has generated too many candidates to
be useful.  A new user-settable variable, "max_completions", is added
to control this behaviour.  A top-level completion limit is added to
complete_line_internal, as the final check to ensure the user never
sees too many completions.  An additional limit is added to
default_make_symbol_completion_list_break_on, to halt time-consuming
symbol table expansions.

gdb/ChangeLog:

	PR cli/9007
	PR cli/11920
	PR cli/15548
	* cli/cli-cmds.c (complete_command): Notify user if max-completions
	reached.
	* common/common-exceptions.h (enum errors)
	<MAX_COMPLETIONS_REACHED_ERROR>: New value.
	* completer.h (get_max_completions_reached_message): New declaration.
	(max_completions): Likewise.
	(completion_tracker_t): New typedef.
	(new_completion_tracker): New declaration.
	(make_cleanup_free_completion_tracker): Likewise.
	(maybe_add_completion_enum): New enum.
	(maybe_add_completion): New declaration.
	(throw_max_completions_reached_error): Likewise.
	* completer.c (max_completions): New global variable.
	(new_completion_tracker): New function.
	(free_completion_tracker): Likewise.
	(make_cleanup_free_completion_tracker): Likewise.
	(maybe_add_completions): Likewise.
	(throw_max_completions_reached_error): Likewise.
	(complete_line): Remove duplicates and limit result to max_completions
	entries.
	(get_max_completions_reached_message): New function.
	(gdb_display_match_list): Handle max_completions.
	(_initialize_completer): New declaration and function.
	* symtab.c: Include completer.h.
	(completion_tracker): New static variable.
	(completion_list_add_name): Call maybe_add_completion.
	(default_make_symbol_completion_list_break_on_1): Renamed from
	default_make_symbol_completion_list_break_on.  Maintain
	completion_tracker across calls to completion_list_add_name.
	(default_make_symbol_completion_list_break_on): New function.
	* top.c (init_main): Set rl_completion_display_matches_hook.
	* tui/tui-io.c: Include completer.h.
	(tui_old_rl_display_matches_hook): New static global.
	(tui_rl_display_match_list): Notify user if max-completions reached.
	(tui_setup_io): Save/restore rl_completion_display_matches_hook.
	* NEWS (New Options): Mention set/show max-completions.

gdb/doc/ChangeLog:

	* gdb.texinfo (Command Completion): Document new
	"set/show max-completions" option.

gdb/testsuite/ChangeLog:

	* gdb.base/completion.exp: Disable completion limiting for
	existing tests.  Add new tests to check completion limiting.
	* gdb.linespec/ls-errs.exp: Disable completion limiting.
2015-01-31 15:07:22 -08:00

181 lines
6.2 KiB
C

/* Header for GDB line completion.
Copyright (C) 2000-2015 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 (COMPLETER_H)
#define COMPLETER_H 1
#include "gdb_vecs.h"
#include "command.h"
/* Types of functions in struct match_list_displayer. */
struct match_list_displayer;
typedef void mld_crlf_ftype (const struct match_list_displayer *);
typedef void mld_putch_ftype (const struct match_list_displayer *, int);
typedef void mld_puts_ftype (const struct match_list_displayer *,
const char *);
typedef void mld_flush_ftype (const struct match_list_displayer *);
typedef void mld_erase_entire_line_ftype (const struct match_list_displayer *);
typedef void mld_beep_ftype (const struct match_list_displayer *);
typedef int mld_read_key_ftype (const struct match_list_displayer *);
/* Interface between CLI/TUI and gdb_match_list_displayer. */
struct match_list_displayer
{
/* The screen dimensions to work with when displaying matches. */
int height, width;
/* Print cr,lf. */
mld_crlf_ftype *crlf;
/* Not "putc" to avoid issues where it is a stdio macro. Sigh. */
mld_putch_ftype *putch;
/* Print a string. */
mld_puts_ftype *puts;
/* Flush all accumulated output. */
mld_flush_ftype *flush;
/* Erase the currently line on the terminal (but don't discard any text the
user has entered, readline may shortly re-print it). */
mld_erase_entire_line_ftype *erase_entire_line;
/* Ring the bell. */
mld_beep_ftype *beep;
/* Read one key. */
mld_read_key_ftype *read_key;
};
extern void gdb_display_match_list (char **matches, int len, int max,
const struct match_list_displayer *);
extern const char *get_max_completions_reached_message (void);
extern VEC (char_ptr) *complete_line (const char *text,
const char *line_buffer,
int point);
extern char *readline_line_completion_function (const char *text,
int matches);
extern VEC (char_ptr) *noop_completer (struct cmd_list_element *,
const char *, const char *);
extern VEC (char_ptr) *filename_completer (struct cmd_list_element *,
const char *, const char *);
extern VEC (char_ptr) *expression_completer (struct cmd_list_element *,
const char *, const char *);
extern VEC (char_ptr) *location_completer (struct cmd_list_element *,
const char *, const char *);
extern VEC (char_ptr) *command_completer (struct cmd_list_element *,
const char *, const char *);
extern VEC (char_ptr) *signal_completer (struct cmd_list_element *,
const char *, const char *);
extern VEC (char_ptr) *reg_or_group_completer (struct cmd_list_element *,
const char *, const char *);
extern char *get_gdb_completer_quote_characters (void);
extern char *gdb_completion_word_break_characters (void);
/* Set the word break characters array to the corresponding set of
chars, based on FN. This function is useful for cases when the
completer doesn't know the type of the completion until some
calculation is done (e.g., for Python functions). */
extern void set_gdb_completion_word_break_characters (completer_ftype *fn);
/* Exported to linespec.c */
extern const char *skip_quoted_chars (const char *, const char *,
const char *);
extern const char *skip_quoted (const char *);
/* Maximum number of candidates to consider before the completer
bails by throwing MAX_COMPLETIONS_REACHED_ERROR. Negative values
disable limiting. */
extern int max_completions;
/* Object to track how many unique completions have been generated.
Used to limit the size of generated completion lists. */
typedef htab_t completion_tracker_t;
/* Create a new completion tracker.
The result is a hash table to track added completions, or NULL
if max_completions <= 0. If max_completions < 0, tracking is disabled.
If max_completions == 0, the max is indeed zero. */
extern completion_tracker_t new_completion_tracker (void);
/* Make a cleanup to free a completion tracker, and reset its pointer
to NULL. */
extern struct cleanup *make_cleanup_free_completion_tracker
(completion_tracker_t *tracker_ptr);
/* Return values for maybe_add_completion. */
enum maybe_add_completion_enum
{
/* NAME has been recorded and max_completions has not been reached,
or completion tracking is disabled (max_completions < 0). */
MAYBE_ADD_COMPLETION_OK,
/* NAME has been recorded and max_completions has been reached
(thus the caller can stop searching). */
MAYBE_ADD_COMPLETION_OK_MAX_REACHED,
/* max-completions entries has been reached.
Whether NAME is a duplicate or not is not determined. */
MAYBE_ADD_COMPLETION_MAX_REACHED,
/* NAME has already been recorded.
Note that this is never returned if completion tracking is disabled
(max_completions < 0). */
MAYBE_ADD_COMPLETION_DUPLICATE
};
/* Add the completion NAME to the list of generated completions if
it is not there already.
If max_completions is negative, nothing is done, not even watching
for duplicates, and MAYBE_ADD_COMPLETION_OK is always returned.
If MAYBE_ADD_COMPLETION_MAX_REACHED is returned, callers are required to
record at least one more completion. The final list will be pruned to
max_completions, but recording at least one more than max_completions is
the signal to the completion machinery that too many completions were
found. */
extern enum maybe_add_completion_enum
maybe_add_completion (completion_tracker_t tracker, char *name);
/* Wrapper to throw MAX_COMPLETIONS_REACHED_ERROR. */
extern void throw_max_completions_reached_error (void);
#endif /* defined (COMPLETER_H) */