old-cross-binutils/gdb/common/gdb_signals.h
Pedro Alves c9737c08e7 infrun debug output: print enum gdb_signal symbol names instead of POSIX signal names.
The other day while debugging something related to random signals, I
got confused with "set debug infrun 1" output, for it said:

 infrun: TARGET_WAITKIND_STOPPED
 infrun: stop_pc = 0x323d4e8b94
 infrun: random signal 20

On GNU/Linux, 20 is SIGTSTP.  For some reason, it took me a few
minutes to realize that 20 is actually a GDB signal number, not a
target signal number (duh!).  In any case, I propose making GDB's
output clearer here:

One way would be to use gdb_signal_to_name, like already used
elsewhere:

 infrun: TARGET_WAITKIND_STOPPED
 infrun: stop_pc = 0x323d4e8b94
 infrun: random signal SIGCHLD (20)

but I think that might confuse someone too ("20? Why does GDB believe
SIGCHLD is 20?").  So I thought of printing the enum string instead:

 infrun: TARGET_WAITKIND_STOPPED
 infrun: stop_pc = 0x323d4e8b94
 infrun: random signal GDB_SIGNAL_CHLD (20)

Looking at a more complete infrun debug log, we had actually printed
the (POSIX) signal name name a bit before:

 infrun: target_wait (-1, status) =
 infrun:   9300 [Thread 0x7ffff7fcb740 (LWP 9300)],
 infrun:   status->kind = stopped, signal = SIGCHLD
 ...
 infrun: TARGET_WAITKIND_STOPPED
 infrun: stop_pc = 0x323d4e8b94
 infrun: random signal 20

So I'm now thinking that it'd be even better to make infrun output
consistently use the enum symbol string, like so:

 infrun: clear_proceed_status_thread (Thread 0x7ffff7fca700 (LWP 25663))
 infrun: clear_proceed_status_thread (Thread 0x7ffff7fcb740 (LWP 25659))
- infrun: proceed (addr=0xffffffffffffffff, signal=144, step=1)
+ infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT, step=1)
- infrun: resume (step=1, signal=0), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
+ infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
 infrun: wait_for_inferior ()
 infrun: target_wait (-1, status) =
 infrun:   25659 [Thread 0x7ffff7fcb740 (LWP 25659)],
- infrun:   status->kind = stopped, signal = SIGCHLD
+ infrun:   status->kind = stopped, signal = GDB_SIGNAL_CHLD
 infrun: infwait_normal_state
 infrun: TARGET_WAITKIND_STOPPED
 infrun: stop_pc = 0x400700
- infrun: random signal 20
+ infrun: random signal (GDB_SIGNAL_CHLD)
 infrun: random signal, keep going
- infrun: resume (step=1, signal=20), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
+ infrun: resume (step=1, signal=GDB_SIGNAL_CHLD), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
 infrun: prepare_to_wait
 infrun: target_wait (-1, status) =
 infrun:   25659 [Thread 0x7ffff7fcb740 (LWP 25659)],
- infrun:   status->kind = stopped, signal = SIGTRAP
+ infrun:   status->kind = stopped, signal = GDB_SIGNAL_TRAP
 infrun: infwait_normal_state
 infrun: TARGET_WAITKIND_STOPPED
 infrun: stop_pc = 0x400704
 infrun: stepi/nexti
 infrun: stop_stepping

GDB's signal numbers are public and hardcoded (see
include/gdb/signals.h), so there's really no need to clutter the
output with numeric values in some places while others not.  Replacing
the magic "144" with GDB_SIGNAL_DEFAULT in "proceed"'s debug output
(see above) I think is quite nice.

I posit that all this makes it clearer to newcomers that GDB has its
own signal numbering (and that there must be some mapping going on).

Tested on x86_64 Fedora 17.

gdb/
2013-10-23  Pedro Alves  <palves@redhat.com>

	* common/gdb_signals.h (gdb_signal_to_symbol_string): Declare.
	* common/signals.c: Include "gdb_assert.h".
	(signals): New field 'symbol'.
	(SET): Use the 'symbol' parameter.
	(gdb_signal_to_symbol_string): New function.
	* infrun.c (handle_inferior_event) <random signal>: In debug
	output, print the random signal enum as string in addition to its
	number.
	* target/waitstatus.c (target_waitstatus_to_string): Print the
	signal's enum value as string instead of the (POSIX) signal name.
2013-10-25 14:02:59 +00:00

58 lines
2.5 KiB
C

/* Target signal translation functions for GDB.
Copyright (C) 1990-2013 Free Software Foundation, Inc.
Contributed by Cygnus Support.
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 COMMON_GDB_SIGNALS_H
#define COMMON_GDB_SIGNALS_H
#include "gdb/signals.h"
/* Predicate to gdb_signal_to_host(). Return non-zero if the enum
targ_signal SIGNO has an equivalent ``host'' representation. */
/* FIXME: cagney/1999-11-22: The name below was chosen in preference
to the shorter gdb_signal_p() because it is far less ambigious.
In this context ``gdb_signal'' refers to GDB's internal
representation of the target's set of signals while ``host signal''
refers to the target operating system's signal. Confused? */
extern int gdb_signal_to_host_p (enum gdb_signal signo);
/* Convert between host signal numbers and enum gdb_signal's.
gdb_signal_to_host() returns 0 and prints a warning() on GDB's
console if SIGNO has no equivalent host representation. */
/* FIXME: cagney/1999-11-22: Here ``host'' is used incorrectly, it is
refering to the target operating system's signal numbering.
Similarly, ``enum gdb_signal'' is named incorrectly, ``enum
gdb_signal'' would probably be better as it is refering to GDB's
internal representation of a target operating system's signal. */
extern enum gdb_signal gdb_signal_from_host (int);
extern int gdb_signal_to_host (enum gdb_signal);
/* Return the enum symbol name of SIG as a string, to use in debug
output. */
extern const char *gdb_signal_to_symbol_string (enum gdb_signal sig);
/* Return the string for a signal. */
extern const char *gdb_signal_to_string (enum gdb_signal);
/* Return the name (SIGHUP, etc.) for a signal. */
extern const char *gdb_signal_to_name (enum gdb_signal);
/* Given a name (SIGHUP, etc.), return its signal. */
enum gdb_signal gdb_signal_from_name (const char *);
#endif /* COMMON_GDB_SIGNALS_H */