Eliminate STOP_SIGNAL, use SIGTSTP directly

The STOP_SIGNAL macro was originally added for Convex Unix
(https://en.wikipedia.org/wiki/Convex_Computer).

In:

  git show 7a67dd45ca1c:gdb/m-convex.h

we see:

~~~
  /* Use SIGCONT rather than SIGTSTP because convex Unix occasionally
     turkeys SIGTSTP.  I think.  */

  #define STOP_SIGNAL SIGCONT
~~~

That's gdb-3.5, 1990...  In gdb/ChangeLog-3.x we see:

~~~
Tue Apr 18 13:43:37 1989  Randall Smith  (randy at apple-gunkies.ai.mit.edu)

        Various changes involved in 1) getting gdb to work on the convex,
	[...]
        Made whatever signal indicates a stop configurable (via macro
        STOP_SIGNAL).
        (main): Setup use of above as a signal handler.  Added check for
        "-nw" in args already processed.
        (command_line_input): SIGTSTP ==>STOP_SIGNAL.
~~~

Support for Convex Unix is long gone, and nothing else overrides
STOP_SIGNAL.  So just use SIGTSTP directly, removing a little
obfuscation.

(I don't really understand why we override [1] readline's SIGTSTP
handler (only) when reading scripts (and then fail to restore it
properly, assuming SIG_DFL...), but I'll leave that for another pass.

[1] - Actually, starting with readline 6.3, readline is no longer
installing its handlers while GDB is in control...)

gdb/ChangeLog:
2017-11-06  Pedro Alves  <palves@redhat.com>

	* event-top.c: Check SIGTSTP instead of STOP_SIGNAL thoughout.
	(async_init_signals): Adjust.
	(handle_stop_sig): Rename to ...
	(handle_sigtstp): ... this.
	(async_stop_sig): Rename to ...
	(async_sigtstp_handler): ... this, and delete STOP_SIGNAL !=
	SIGTSTP path.
	* event-top.h: Move signal.h include to the top.  Check SIGTSTP
	instead of STOP_SIGNAL thoughout.
	(handle_stop_sig): Rename to ...
	(handle_sigtstp): ... this.
	* top.c (command_line_input): Replace STOP_SIGNAL -> SIGTSTP.
This commit is contained in:
Pedro Alves 2017-11-06 15:36:47 +00:00
parent a94799ac1e
commit 6aa899ce25
4 changed files with 34 additions and 25 deletions

View File

@ -1,3 +1,18 @@
2017-11-06 Pedro Alves <palves@redhat.com>
* event-top.c: Check SIGTSTP instead of STOP_SIGNAL thoughout.
(async_init_signals): Adjust.
(handle_stop_sig): Rename to ...
(handle_sigtstp): ... this.
(async_stop_sig): Rename to ...
(async_sigtstp_handler): ... this, and delete STOP_SIGNAL !=
SIGTSTP path.
* event-top.h: Move signal.h include to the top. Check SIGTSTP
instead of STOP_SIGNAL thoughout.
(handle_stop_sig): Rename to ...
(handle_sigtstp): ... this.
* top.c (command_line_input): Replace STOP_SIGNAL -> SIGTSTP.
2017-11-06 Pedro Alves <palves@redhat.com>
* inflow.c (child_terminal_inferior, child_terminal_ours_1): No

View File

@ -68,8 +68,8 @@ static void async_do_nothing (gdb_client_data);
static void async_disconnect (gdb_client_data);
#endif
static void async_float_handler (gdb_client_data);
#ifdef STOP_SIGNAL
static void async_stop_sig (gdb_client_data);
#ifdef SIGTSTP
static void async_sigtstp_handler (gdb_client_data);
#endif
static void async_sigterm_handler (gdb_client_data arg);
@ -111,7 +111,7 @@ static struct async_signal_handler *sighup_token;
static struct async_signal_handler *sigquit_token;
#endif
static struct async_signal_handler *sigfpe_token;
#ifdef STOP_SIGNAL
#ifdef SIGTSTP
static struct async_signal_handler *sigtstp_token;
#endif
static struct async_signal_handler *async_sigterm_token;
@ -912,9 +912,9 @@ async_init_signals (void)
sigfpe_token =
create_async_signal_handler (async_float_handler, NULL);
#ifdef STOP_SIGNAL
#ifdef SIGTSTP
sigtstp_token =
create_async_signal_handler (async_stop_sig, NULL);
create_async_signal_handler (async_sigtstp_handler, NULL);
#endif
}
@ -1112,20 +1112,19 @@ async_disconnect (gdb_client_data arg)
}
#endif
#ifdef STOP_SIGNAL
#ifdef SIGTSTP
void
handle_stop_sig (int sig)
handle_sigtstp (int sig)
{
mark_async_signal_handler (sigtstp_token);
signal (sig, handle_stop_sig);
signal (sig, handle_sigtstp);
}
static void
async_stop_sig (gdb_client_data arg)
async_sigtstp_handler (gdb_client_data arg)
{
char *prompt = get_prompt ();
#if STOP_SIGNAL == SIGTSTP
signal (SIGTSTP, SIG_DFL);
#if HAVE_SIGPROCMASK
{
@ -1138,10 +1137,7 @@ async_stop_sig (gdb_client_data arg)
sigsetmask (0);
#endif
raise (SIGTSTP);
signal (SIGTSTP, handle_stop_sig);
#else
signal (STOP_SIGNAL, handle_stop_sig);
#endif
signal (SIGTSTP, handle_sigtstp);
printf_unfiltered ("%s", prompt);
gdb_flush (gdb_stdout);
@ -1149,7 +1145,7 @@ async_stop_sig (gdb_client_data arg)
nothing. */
dont_repeat ();
}
#endif /* STOP_SIGNAL */
#endif /* SIGTSTP */
/* Tell the event loop what to do if SIGFPE is received.
See event-signal.c. */

View File

@ -22,6 +22,8 @@
#ifndef EVENT_TOP_H
#define EVENT_TOP_H
#include <signal.h>
struct cmd_list_element;
/* Exported functions from event-top.c.
@ -36,14 +38,10 @@ extern void change_line_handler (int);
extern void command_line_handler (char *rl);
extern void command_handler (char *command);
/* Signal to catch ^Z typed while reading a command: SIGTSTP or SIGCONT. */
#ifndef STOP_SIGNAL
#include <signal.h>
#ifdef SIGTSTP
#define STOP_SIGNAL SIGTSTP
extern void handle_stop_sig (int sig);
#endif
extern void handle_sigtstp (int sig);
#endif
extern void handle_sigint (int sig);
extern void handle_sigterm (int sig);
extern void async_request_quit (void *arg);

View File

@ -1184,9 +1184,9 @@ command_line_input (const char *prompt_arg, int repeat,
/* Starting a new command line. */
cmd_line_buffer.used_size = 0;
#ifdef STOP_SIGNAL
#ifdef SIGTSTP
if (job_control)
signal (STOP_SIGNAL, handle_stop_sig);
signal (SIGTSTP, handle_sigtstp);
#endif
while (1)
@ -1244,9 +1244,9 @@ command_line_input (const char *prompt_arg, int repeat,
prompt = NULL;
}
#ifdef STOP_SIGNAL
#ifdef SIGTSTP
if (job_control)
signal (STOP_SIGNAL, SIG_DFL);
signal (SIGTSTP, SIG_DFL);
#endif
return cmd;