binutils-gdb/gdb/top.h
Pedro Alves 3b12939dfc Replace the sync_execution global with a new enum prompt_state tristate
When sync_execution (a boolean) is true, it means we're running a
foreground command -- we hide the prompt stop listening to input, give
the inferior the terminal, then go to the event loop waiting for the
target to stop.

With multiple independent UIs, we need to track whether each UI is
synchronously blocked waiting for the target.  IOW, if you do
"continue" in one console, that console stops accepting commands, but
you should still be free to type other commands in the others
consoles.

Just simply making sync_execution be per-UI alone not sufficient,
because of this in fetch_inferior_event:

  /* If the inferior was in sync execution mode, and now isn't,
     restore the prompt (a synchronous execution command has finished,
     and we're ready for input).  */
  if (current_ui->async && was_sync && !sync_execution)
    observer_notify_sync_execution_done ();

We'd have to record at entry the "was_sync" state for each UI, not
just of the current UI.

This patch instead replaces the sync_execution flag by a per-UI
tristate flag indicating the command line prompt state:

 enum prompt_state
 {
   /* The command line is blocked simulating synchronous execution.
      This is used to implement the foreground execution commands
      ('run', 'continue', etc.).  We won't display the prompt and
      accept further commands until the execution is actually over.  */
   PROMPT_BLOCKED,

   /* The command finished; display the prompt before returning back to
      the top level.  */
   PROMPT_NEEDED,

   /* We've displayed the prompt already, ready for input.  */
   PROMPTED,
 ;

I think the end result is _much_ clearer than the current code, and,
it addresses the original motivation too.

gdb/ChangeLog:
2016-06-21  Pedro Alves  <palves@redhat.com>

	* annotate.c: Include top.h.
	(async_background_execution_p): Delete.
	(print_value_flags): Check the UI's prompt state rather then
	async_background_execution_p.
	* event-loop.c (start_event_loop): Set the prompt state to
	PROMPT_NEEDED.
	* event-top.c (display_gdb_prompt, async_enable_stdin)
	(async_disable_stdin): Check the current UI's prompt state instead
	of the sync_execution global.
	(command_line_handler): Set the prompt state to PROMPT_NEEDED
	before running a command, and display the prompt if still needed
	afterwards.
	* infcall.c (struct call_thread_fsm) <waiting_ui>: New field.
	(new_call_thread_fsm): New parameter 'waiting_ui'.  Store it.
	(call_thread_fsm_should_stop): Set the prompt state to
	PROMPT_NEEDED.
	(run_inferior_call): Adjust to temporarily set the prompt state to
	PROMPT_BLOCKED instead of using the sync_execution global.
	(call_function_by_hand_dummy): Pass the current UI to
	new_call_thread_fsm.
	* infcmd.c: Include top.h.
	(continue_1): Check the current UI's prompt state instead of the
	sync_execution global.
	(continue_command): Validate global execution state before calling
	prepare_execution_command.
	(step_1): Call all_uis_check_sync_execution_done.
	(attach_post_wait): Don't call async_enable_stdin here.  Remove
	reference to sync_execution.
	* infrun.c (sync_execution): Delete global.
	(follow_fork_inferior)
	(reinstall_readline_callback_handler_cleanup): Check the current
	UI's prompt state instead of the sync_execution global.
	(check_curr_ui_sync_execution_done)
	(all_uis_check_sync_execution_done): New functions.
	(fetch_inferior_event): Call all_uis_check_sync_execution_done
	instead of trying to determine whether the global sync execution
	changed.
	(handle_no_resumed): Check the prompt state of all UIs.
	(normal_stop): Emit the no unwait-for even to all PROMPT_BLOCKED
	UIs.  Emit the "Switching to" notification to all UIs.  Enable
	stdin in all UIs.
	* infrun.h (sync_execution): Delete.
	(all_uis_check_sync_execution_done): Declare.
	* main.c (captured_command_loop): Don't call
	interp_pre_command_loop if the prompt is blocked.
	(catch_command_errors, catch_command_errors_const): Adjust.
	(captured_main): Set the initial prompt state to PROMPT_NEEDED.
	* mi/mi-interp.c (display_mi_prompt): Set the prompt state to
	PROMPTED.
	(mi_interpreter_resume): Don't clear sync_execution.  Remove hack
	comment.
	(mi_execute_command_input_handler): Set the prompt state to
	PROMPT_NEEDED before executing the command, and only display the
	prompt if the prompt state is PROMPT_NEEDED afterwards.
	(mi_on_resume_1): Adjust to check the prompt state.
	* target.c (target_terminal_inferior): Adjust to check the prompt
	state.
	* top.c (wait_sync_command_done, maybe_wait_sync_command_done)
	(execute_command): Check the current UI's prompt state instead of
	sync_execution.
	* top.h (enum prompt_state): New.
	(struct ui) <prompt_state>: New field.
	(ALL_UIS): New macro.
2016-06-21 01:11:51 +01:00

257 lines
8.5 KiB
C

/* Top level stuff for GDB, the GNU debugger.
Copyright (C) 1986-2016 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 TOP_H
#define TOP_H
#include "buffer.h"
#include "event-loop.h"
struct tl_interp_info;
/* Prompt state. */
enum prompt_state
{
/* The command line is blocked simulating synchronous execution.
This is used to implement the foreground execution commands
('run', 'continue', etc.). We won't display the prompt and
accept further commands until the execution is actually over. */
PROMPT_BLOCKED,
/* The command finished; display the prompt before returning back to
the top level. */
PROMPT_NEEDED,
/* We've displayed the prompt already, ready for input. */
PROMPTED,
};
/* All about a user interface instance. Each user interface has its
own I/O files/streams, readline state, its own top level
interpreter (for the main UI, this is the interpreter specified
with -i on the command line) and secondary interpreters (for
interpreter-exec ...), etc. There's always one UI associated with
stdin/stdout/stderr, but the user can create secondary UIs, for
example, to create a separate MI channel on its own stdio
streams. */
struct ui
{
/* Pointer to next in singly-linked list. */
struct ui *next;
/* The UI's command line buffer. This is to used to accumulate
input until we have a whole command line. */
struct buffer line_buffer;
/* The callback used by the event loop whenever an event is detected
on the UI's input file descriptor. This function incrementally
builds a buffer where it accumulates the line read up to the
point of invocation. In the special case in which the character
read is newline, the function invokes the INPUT_HANDLER callback
(see below). */
void (*call_readline) (gdb_client_data);
/* The function to invoke when a complete line of input is ready for
processing. */
void (*input_handler) (char *);
/* True if this UI is using the readline library for command
editing; false if using GDB's own simple readline emulation, with
no editing support. */
int command_editing;
/* Each UI has its own independent set of interpreters. */
struct ui_interp_info *interp_info;
/* True if the UI is in async mode, false if in sync mode. If in
sync mode, a synchronous execution command (e.g, "next") does not
return until the command is finished. If in async mode, then
running a synchronous command returns right after resuming the
target. Waiting for the command's completion is later done on
the top event loop. For the main UI, this starts out disabled,
until all the explicit command line arguments (e.g., `gdb -ex
"start" -ex "next"') are processed. */
int async;
/* The number of nested readline secondary prompts that are
currently active. */
int secondary_prompt_depth;
/* stdio stream that command input is being read from. Set to stdin
normally. Set by source_command to the file we are sourcing.
Set to NULL if we are executing a user-defined command or
interacting via a GUI. */
FILE *instream;
/* Standard output stream. */
FILE *outstream;
/* Standard error stream. */
FILE *errstream;
/* The file descriptor for the input stream, so that we can register
it with the event loop. */
int input_fd;
/* See enum prompt_state's description. */
enum prompt_state prompt_state;
/* The fields below that start with "m_" are "private". They're
meant to be accessed through wrapper macros that make them look
like globals. */
/* The ui_file streams. */
/* Normal results */
struct ui_file *m_gdb_stdout;
/* Input stream */
struct ui_file *m_gdb_stdin;
/* Serious error notifications */
struct ui_file *m_gdb_stderr;
/* Log/debug/trace messages that should bypass normal stdout/stderr
filtering. For moment, always call this stream using
*_unfiltered. In the very near future that restriction shall be
removed - either call shall be unfiltered. (cagney 1999-06-13). */
struct ui_file *m_gdb_stdlog;
/* The current ui_out. */
struct ui_out *m_current_uiout;
};
/* The main UI. This is the UI that is bound to stdin/stdout/stderr.
It always exists and is created automatically when GDB starts
up. */
extern struct ui *main_ui;
/* The current UI. */
extern struct ui *current_ui;
/* The list of all UIs. */
extern struct ui *ui_list;
/* State for SWITCH_THRU_ALL_UIS. Declared here because it is meant
to be created on the stack, but should be treated as opaque. */
struct switch_thru_all_uis
{
struct ui *iter;
struct cleanup *old_chain;
};
/* Functions to drive SWITCH_THRU_ALL_UIS. Though declared here by
necessity, these functions should not be used other than via the
SWITCH_THRU_ALL_UIS macro defined below. */
extern void switch_thru_all_uis_init (struct switch_thru_all_uis *state);
extern int switch_thru_all_uis_cond (struct switch_thru_all_uis *state);
extern void switch_thru_all_uis_next (struct switch_thru_all_uis *state);
/* Traverse through all UI, and switch the current UI to the one
being iterated. */
#define SWITCH_THRU_ALL_UIS(STATE) \
for (switch_thru_all_uis_init (&STATE); \
switch_thru_all_uis_cond (&STATE); \
switch_thru_all_uis_next (&STATE))
/* Traverse over all UIs. */
#define ALL_UIS(UI) \
for (UI = ui_list; UI; UI = UI->next) \
/* Cleanup that restores the current UI. */
extern void restore_ui_cleanup (void *data);
/* From top.c. */
extern char *saved_command_line;
extern int in_user_command;
extern int confirm;
extern char gdb_dirbuf[1024];
extern int inhibit_gdbinit;
extern const char gdbinit[];
extern void print_gdb_version (struct ui_file *);
extern void print_gdb_configuration (struct ui_file *);
extern void read_command_file (FILE *);
extern void init_history (void);
extern void command_loop (void);
extern int quit_confirm (void);
extern void quit_force (char *, int);
extern void quit_command (char *, int);
extern void quit_cover (void);
extern void execute_command (char *, int);
/* If the interpreter is in sync mode (we're running a user command's
list, running command hooks or similars), and we just ran a
synchronous command that started the target, wait for that command
to end. WAS_SYNC indicates whether sync_execution was set before
the command was run. */
extern void maybe_wait_sync_command_done (int was_sync);
/* Wait for a synchronous execution command to end. */
extern void wait_sync_command_done (void);
extern void check_frame_language_change (void);
/* Prepare for execution of a command.
Call this before every command, CLI or MI.
Returns a cleanup to be run after the command is completed. */
extern struct cleanup *prepare_execute_command (void);
/* This function returns a pointer to the string that is used
by gdb for its command prompt. */
extern char *get_prompt (void);
/* This function returns a pointer to the string that is used
by gdb for its command prompt. */
extern void set_prompt (const char *s);
/* Return 1 if UI's current input handler is a secondary prompt, 0
otherwise. */
extern int gdb_in_secondary_prompt_p (struct ui *ui);
/* From random places. */
extern int readnow_symbol_files;
/* Perform _initialize initialization. */
extern void gdb_init (char *);
/* For use by event-top.c. */
/* Variables from top.c. */
extern int source_line_number;
extern const char *source_file_name;
extern int history_expansion_p;
extern int server_command;
extern char *lim_at_start;
extern void gdb_add_history (const char *);
extern void show_commands (char *args, int from_tty);
extern void set_history (char *, int);
extern void show_history (char *, int);
extern void set_verbose (char *, int, struct cmd_list_element *);
extern void do_restore_instream_cleanup (void *stream);
extern char *handle_line_of_input (struct buffer *cmd_line_buffer,
char *rl, int repeat,
char *annotation_suffix);
#endif