binutils-gdb/gdb/interps.h
Pedro Alves eb3ff9a551 Introduce class completion_tracker & rewrite completion<->readline interaction
This patch reworks the whole completion machinery, and prepares it
for later enhancements.

Adds a new "completion_tracker" class that is meant to hold everything
about the state of the current completion operation.

This class now has the responsibility of tracking the list of
completion matches, and checking whether the max completions limit has
been reached.  You can look at this as this patch starting out by
C++fying the existing "completion_tracker" in symtab.c (it's just an
htab_t typedef currently), moving it to completer.h/c, and then making
it a class/generalizing/enhancing it.

Unlike with the current tracking, completion_tracker now checks
whether the limit has been reached on each completion match list
insertion.  This both simplifies the max-completions handling code
(maybe_add_completion_enum is gone, for example), and is a
prerequisite for follow up patches.

The current completion_tracker is only used for symbol completions,
and the symbol code gets at the current instance via globals.  This
patch cleans that up by adding a completion_tracker reference to the
signature of the completion functions, and passing the tracker around
everywhere necessary.

Then, the patch changes how the completion match list is handed over
to readline.  Currently, we're using the rl_completion_entry_function
readline entry point, and the patch switches to
rl_attempted_completion_function.  A following patch will want to let
GDB itself decide the common completion prefix between all matches
(what readline calls the "lowest common denominator"), instead of
having readline compute it, and that's not possible with the
rl_completion_entry_function entry point.  Also,
rl_attempted_completion_function lets GDB hand over the match list to
readline as an array in one go instead of passing down matches one by
one, so from that angle it's a nicer entry point anyway.

Lastly, the patch catches exceptions around the readline entry points,
because we can't let C++ exceptions cross readline.  We handle that in
the readline input entry point, but the completion entry point isn't
guarded, so GDB can abort if completion throws.  E.g., in current
master:

 (gdb) b -function "fun<tab>
 terminate called after throwing an instance of 'gdb_exception_RETURN_MASK_ERROR'
 Aborted (core dumped)

This patch fixes that.  This will be exercised in the new tests added
later on in the series.

gdb/ChangeLog:
2017-07-17  Pedro Alves  <palves@redhat.com>

	* ada-lang.c (symbol_completion_match): Adjust comments.
	(symbol_completion_add): Replace vector parameter with
	completion_tracker parameter.  Use it.
	(ada_make_symbol_completion_list): Rename to...
	(ada_collect_symbol_completion_matches): ... this.  Add
	completion_tracker parameter and use it.
	(ada_language_defn): Adjust.
	* break-catch-syscall.c (catch_syscall_completer): Adjust
	prototype and work with completion_tracker instead of VEC.
	* breakpoint.c (condition_completer): Adjust prototype and work
	with completion_tracker instead of VEC.
	* c-lang.c (c_language_defn, cplus_language_defn)
	(asm_language_defn, minimal_language_defn): Adjust to renames.
	* cli/cli-cmds.c (complete_command): Rework using
	completion_tracker.  Catch exceptions when completing.
	* cli/cli-decode.c (integer_unlimited_completer)
	(complete_on_cmdlist, complete_on_enum): Adjust prototype and work
	with completion_tracker instead of VEC.
	* command.h (struct completion_tracker): Forward declare.
	(completer_ftype, completer_handle_brkchars_ftype): Change
	types.
	(complete_on_cmdlist, complete_on_enum): Adjust.
	* completer.c: Include <algorithm>.
	(struct gdb_completer_state): New.
	(current_completion): New global.
	(readline_line_completion_function): Delete.
	(noop_completer, filename_completer)
	(filename_completer_handle_brkchars, complete_files_symbols)
	(linespec_location_completer): Adjust to work with a
	completion_tracker instead of a VEC.
	(string_or_empty): New.
	(collect_explicit_location_matches): Adjust to work with a
	completion_tracker instead of a VEC.
	(explicit_location_completer): Rename to ...
	(complete_explicit_location): ... this and adjust to work with a
	completion_tracker instead of a VEC.
	(location_completer): Adjust to work with a completion_tracker
	instead of a VEC.
	(add_struct_fields): Adjust to work with a completion_list instead
	of VEC.
	(expression_completer): Rename to ...
	(complete_expression): ... this and adjust to work with a
	completion_tracker instead of a VEC.  Use complete_files_symbols.
	(expression_completer): Reimplement on top of complete_expression.
	(symbol_completer): Adjust to work with a completion_tracker
	instead of a VEC.
	(enum complete_line_internal_reason): Add describing comments.
	(complete_line_internal_normal_command): Adjust to work with a
	completion_tracker instead of a VEC.
	(complete_line_internal): Rename to ...
	(complete_line_internal_1): ... this and adjust to work with a
	completion_tracker instead of a VEC.  Assert TEXT is NULL in the
	handle_brkchars phase.
	(new_completion_tracker): Delete.
	(complete_line_internal): Reimplement as TRY/CATCH wrapper around
	complete_line_internal_1.
	(free_completion_tracker): Delete.
	(INITIAL_COMPLETION_HTAB_SIZE): New.
	(completion_tracker::completion_tracker)
	(completion_tracker::~completion_tracker): New.
	(maybe_add_completion): Delete.
	(completion_tracker::maybe_add_completion)
	(completion_tracker::add_completion)
	(completion_tracker::add_completions): New.
	(throw_max_completions_reached_error): Delete.
	(complete_line): Adjust to work with a completion_tracker instead
	of a VEC.  Don't create a completion_tracker_t or check for max
	completions here.
	(command_completer, command_completer_handle_brkchars)
	(signal_completer, reg_or_group_completer_1)
	(reg_or_group_completer, default_completer_handle_brkchars):
	Adjust to work with a completion_tracker.
	(gdb_completion_word_break_characters_throw): New.
	(gdb_completion_word_break_characters): Reimplement.
	(line_completion_function): Delete.
	(completion_tracker::recompute_lowest_common_denominator)
	(expand_preserving_ws)
	(completion_tracker::build_completion_result)
	(completion_result::completion_result)
	(completion_result::completion_result)
	(completion_result::~completion_result)
	(completion_result::completion_result)
	(completion_result::release_match_list, compare_cstrings)
	(completion_result::sort_match_list)
	(completion_result::reset_match_list)
	(gdb_rl_attempted_completion_function_throw)
	(gdb_rl_attempted_completion_function): New.
	* completer.h (completion_list, struct completion_result)
	(class completion_tracker): New.
	(complete_line): Add completion_tracker parameter.
	(readline_line_completion_function): Delete.
	(gdb_rl_attempted_completion_function): New.
	(noop_completer, filename_completer, expression_completer)
	(location_completer, symbol_completer, command_completer)
	(signal_completer, reg_or_group_completer): Update prototypes.
	(completion_tracker_t, new_completion_tracker)
	(make_cleanup_free_completion_tracker): Delete.
	(enum maybe_add_completion_enum): Delete.
	(maybe_add_completion): Delete.
	(throw_max_completions_reached_error): Delete.
	* corefile.c (complete_set_gnutarget): Adjust to work with a
	completion_tracker instead of a VEC.
	* cp-abi.c (cp_abi_completer): Adjust to work with a
	completion_tracker instead of a VEC.
	* d-lang.c (d_language_defn): Adjust.
	* disasm.c (disassembler_options_completer): Adjust to work with a
	completion_tracker instead of a VEC.
	* f-lang.c (f_make_symbol_completion_list): Rename to ...
	(f_collect_symbol_completion_matches): ... this.  Adjust to work
	with a completion_tracker instead of a VEC.
	(f_language_defn): Adjust.
	* go-lang.c (go_language_defn): Adjust.
	* guile/scm-cmd.c (cmdscm_add_completion, cmdscm_completer):
	Adjust to work with a completion_tracker instead of a VEC.
	* infrun.c (handle_completer): Likewise.
	* interps.c (interpreter_completer): Likewise.
	* interps.h (interpreter_completer): Likewise.
	* language.c (unknown_language_defn, auto_language_defn)
	(local_language_defn): Adjust.
	* language.h (language_defn::la_make_symbol_completion_list):
	Rename to ...
	(language_defn::la_collect_symbol_completion_matches): ... this
	and adjust to work with a completion_tracker instead of a VEC.
	* m2-lang.c (m2_language_defn): Adjust.
	* objc-lang.c (objc_language_defn): Adjust.
	* opencl-lang.c (opencl_language_defn): Adjust.
	* p-lang.c (pascal_language_defn): Adjust.
	* python/py-cmd.c (cmdpy_completer_helper): Handle NULL word.
	(cmdpy_completer_handle_brkchars, cmdpy_completer): Adjust to work
	with a completion_tracker.
	* rust-lang.c (rust_language_defn): Adjust.
	* symtab.c (free_completion_list, do_free_completion_list)
	(return_val, completion_tracker): Delete.
	(completion_list_add_name, completion_list_add_symbol)
	(completion_list_add_msymbol, completion_list_objc_symbol)
	(completion_list_add_fields, add_symtab_completions): Add
	completion_tracker parameter and use it.
	(default_make_symbol_completion_list_break_on_1): Rename to...
	(default_collect_symbol_completion_matches_break_on): ... this.
	Add completion_tracker parameter and use it instead of allocating
	a completion tracker here.
	(default_make_symbol_completion_list_break_on): Delete old
	implementation.
	(default_make_symbol_completion_list): Delete.
	(default_collect_symbol_completion_matches): New.
	(make_symbol_completion_list): Delete.
	(collect_symbol_completion_matches): New.
	(make_symbol_completion_type): Rename to ...
	(collect_symbol_completion_matches_type): ... this.  Add
	completion_tracker parameter and use it instead of VEC.
	(make_file_symbol_completion_list_1): Rename to...
	(collect_file_symbol_completion_matches): ... this.  Add
	completion_tracker parameter and use it instead of VEC.
	(make_file_symbol_completion_list): Delete.
	(add_filename_to_list): Use completion_list instead of a VEC.
	(add_partial_filename_data::list): Now a completion_list.
	(make_source_files_completion_list): Work with a completion_list
	instead of a VEC.
	* symtab.h: Include "completer.h".
	(default_make_symbol_completion_list_break_on)
	(default_make_symbol_completion_list, make_symbol_completion_list)
	(make_symbol_completion_type, make_file_symbol_completion_list)
	(make_source_files_completion_list): Delete.
	(default_collect_symbol_completion_matches_break_on)
	(default_collect_symbol_completion_matches)
	(collect_symbol_completion_matches)
	(collect_symbol_completion_matches_type)
	(collect_file_symbol_completion_matches)
	(make_source_files_completion_list): New.
	* top.c (init_main): Don't install a rl_completion_entry_function
	hook.  Install a rl_attempted_completion_function hook instead.
	* tui/tui-layout.c (layout_completer): Adjust to work with a
	completion_tracker.
	* tui/tui-regs.c (tui_reggroup_completer):
	* tui/tui-win.c (window_name_completer, focus_completer)
	(winheight_completer): Adjust to work with a completion_tracker.
	* value.c: Include "completer.h".
	(complete_internalvar): Adjust to work with a completion_tracker.
	* value.h (complete_internalvar): Likewise.
2017-07-17 14:45:59 +01:00

156 lines
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C++

/* Manages interpreters for GDB, the GNU debugger.
Copyright (C) 2000-2017 Free Software Foundation, Inc.
Written by Jim Ingham <jingham@apple.com> of Apple Computer, 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 INTERPS_H
#define INTERPS_H
struct ui_out;
struct interp;
struct ui;
typedef struct interp *(*interp_factory_func) (const char *name);
/* Each interpreter kind (CLI, MI, etc.) registers itself with a call
to this function, passing along its name, and a pointer to a
function that creates a new instance of an interpreter with that
name. */
extern void interp_factory_register (const char *name,
interp_factory_func func);
extern int interp_resume (struct interp *interp);
extern int interp_suspend (struct interp *interp);
extern struct gdb_exception interp_exec (struct interp *interp,
const char *command);
class interp
{
public:
explicit interp (const char *name);
virtual ~interp () = 0;
virtual void init (bool top_level)
{}
virtual void resume () = 0;
virtual void suspend () = 0;
virtual gdb_exception exec (const char *command) = 0;
/* Returns the ui_out currently used to collect results for this
interpreter. It can be a formatter for stdout, as is the case
for the console & mi outputs, or it might be a result
formatter. */
virtual ui_out *interp_ui_out () = 0;
/* Provides a hook for interpreters to do any additional
setup/cleanup that they might need when logging is enabled or
disabled. */
virtual void set_logging (ui_file_up logfile, bool logging_redirect) = 0;
/* Called before starting an event loop, to give the interpreter a
chance to e.g., print a prompt. */
virtual void pre_command_loop ()
{}
/* Returns true if this interpreter supports using the readline
library; false if it uses GDB's own simplified readline
emulation. */
virtual bool supports_command_editing ()
{ return false; }
/* This is the name in "-i=" and "set interpreter". */
const char *name;
/* Interpreters are stored in a linked list, this is the next
one... */
struct interp *next;
/* Has the init method been run? */
bool inited;
};
extern void interp_add (struct ui *ui, struct interp *interp);
/* Look up the interpreter for NAME, creating one if none exists yet.
If NAME is not a interpreter type previously registered with
interp_factory_register, return NULL; otherwise return a pointer to
the interpreter. */
extern struct interp *interp_lookup (struct ui *ui, const char *name);
/* Set the current UI's top level interpreter to the interpreter named
NAME. Throws an error if NAME is not a known interpreter or the
interpreter fails to initialize. */
extern void set_top_level_interpreter (const char *name);
extern struct ui_out *interp_ui_out (struct interp *interp);
extern const char *interp_name (struct interp *interp);
extern struct interp *interp_set_temp (const char *name);
extern int current_interp_named_p (const char *name);
/* Call this function to give the current interpreter an opportunity
to do any special handling of streams when logging is enabled or
disabled. LOGFILE is the stream for the log file when logging is
starting and is NULL when logging is ending. LOGGING_REDIRECT is
the value of the "set logging redirect" setting. If true, the
interpreter should configure the output streams to send output only
to the logfile. If false, the interpreter should configure the
output streams to send output to both the current output stream
(i.e., the terminal) and the log file. */
extern void current_interp_set_logging (ui_file_up logfile,
bool logging_redirect);
/* Returns the top-level interpreter. */
extern struct interp *top_level_interpreter (void);
/* Return the current UI's current interpreter. */
extern struct interp *current_interpreter (void);
extern struct interp *command_interp (void);
extern void clear_interpreter_hooks (void);
/* Returns true if INTERP supports using the readline library; false
if it uses GDB's own simplified form of readline. */
extern int interp_supports_command_editing (struct interp *interp);
/* Called before starting an event loop, to give the interpreter a
chance to e.g., print a prompt. */
extern void interp_pre_command_loop (struct interp *interp);
/* List the possible interpreters which could complete the given
text. */
extern void interpreter_completer (struct cmd_list_element *ignore,
completion_tracker &tracker,
const char *text,
const char *word);
/* well-known interpreters */
#define INTERP_CONSOLE "console"
#define INTERP_MI1 "mi1"
#define INTERP_MI2 "mi2"
#define INTERP_MI3 "mi3"
#define INTERP_MI "mi"
#define INTERP_TUI "tui"
#define INTERP_INSIGHT "insight"
#endif