Gimp/app/errors.c
Jehan 5de7aab482 app: replace g_on_error_query() and g_on_error_stack_trace() by...
... our own implementation.
Though the GUI stacktrace is better for most (because it is visible even
when not run in a terminal), the CLI options are quite useful too and
may still be preferred by some, in particular developers. So it may as
well be benefiting from the better implementation. Glib traces are quite
weak even though they also use gdb and debug info are present (often,
even though I had these traces, I had to run gdb separately; now it
won't be necessary in many cases). My traces include more information.

Note that I didn't implement gimp_print_stack_trace() from previous
gimp_get_stack_trace() because I cannot allocate a string after some
types of crash (e.g. segmentation faults). So instead,
gimp_print_stack_trace() now take care optionally of both cases: either
allocating a string, or directly pipe to a file descriptor.
2018-02-08 16:37:19 +01:00

582 lines
17 KiB
C

/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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/>.
*/
#include "config.h"
#define _GNU_SOURCE /* need the POSIX signal API */
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <sys/wait.h>
#ifdef HAVE_EXECINFO_H
/* Allowing backtrace() API. */
#include <execinfo.h>
#endif
#include <gio/gio.h>
#include <glib/gprintf.h>
#include "libgimpbase/gimpbase.h"
#include "core/core-types.h"
#include "core/gimp.h"
#include "errors.h"
#ifdef G_OS_WIN32
#include <windows.h>
#endif
#define MAX_TRACES 3
/* private variables */
static Gimp *the_errors_gimp = NULL;
static gboolean use_debug_handler = FALSE;
static GimpStackTraceMode stack_trace_mode = GIMP_STACK_TRACE_QUERY;
static gchar *full_prog_name = NULL;
static gchar *backtrace_file = NULL;
/* local function prototypes */
static void gimp_third_party_message_log_func (const gchar *log_domain,
GLogLevelFlags flags,
const gchar *message,
gpointer data);
static void gimp_message_log_func (const gchar *log_domain,
GLogLevelFlags flags,
const gchar *message,
gpointer data);
static void gimp_error_log_func (const gchar *domain,
GLogLevelFlags flags,
const gchar *message,
gpointer data) G_GNUC_NORETURN;
static G_GNUC_NORETURN void gimp_eek (const gchar *reason,
const gchar *message,
gboolean use_handler);
static gboolean gimp_print_stack_trace (FILE *file,
gchar **trace);
static void gimp_on_error_query (void);
/* public functions */
void
errors_init (Gimp *gimp,
const gchar *_full_prog_name,
gboolean _use_debug_handler,
GimpStackTraceMode _stack_trace_mode,
const gchar *_backtrace_file)
{
const gchar * const log_domains[] =
{
"Gimp",
"Gimp-Actions",
"Gimp-Base",
"Gimp-Composite",
"Gimp-Config",
"Gimp-Core",
"Gimp-Dialogs",
"Gimp-Display",
"Gimp-File",
"Gimp-GEGL",
"Gimp-GUI",
"Gimp-Menus",
"Gimp-Operations",
"Gimp-PDB",
"Gimp-Paint",
"Gimp-Paint-Funcs",
"Gimp-Plug-In",
"Gimp-Text",
"Gimp-Tools",
"Gimp-Vectors",
"Gimp-Widgets",
"Gimp-XCF",
"LibGimpBase",
"LibGimpColor",
"LibGimpConfig",
"LibGimpMath",
"LibGimpModule",
"LibGimpThumb",
"LibGimpWidgets"
};
gint i;
g_return_if_fail (GIMP_IS_GIMP (gimp));
g_return_if_fail (_full_prog_name != NULL);
g_return_if_fail (full_prog_name == NULL);
#ifdef GIMP_UNSTABLE
g_printerr ("This is a development version of GIMP. "
"Debug messages may appear here.\n\n");
#endif /* GIMP_UNSTABLE */
the_errors_gimp = gimp;
use_debug_handler = _use_debug_handler ? TRUE : FALSE;
stack_trace_mode = _stack_trace_mode;
full_prog_name = g_strdup (_full_prog_name);
backtrace_file = g_strdup (_backtrace_file);
for (i = 0; i < G_N_ELEMENTS (log_domains); i++)
g_log_set_handler (log_domains[i],
#ifdef GIMP_UNSTABLE
G_LOG_LEVEL_WARNING |
#endif
G_LOG_LEVEL_MESSAGE | G_LOG_LEVEL_CRITICAL,
gimp_message_log_func, gimp);
g_log_set_handler ("GEGL",
G_LOG_LEVEL_MESSAGE,
gimp_third_party_message_log_func, gimp);
g_log_set_handler (NULL,
G_LOG_LEVEL_ERROR | G_LOG_FLAG_FATAL,
gimp_error_log_func, gimp);
}
void
errors_exit (void)
{
the_errors_gimp = NULL;
if (backtrace_file)
g_free (backtrace_file);
}
void
gimp_fatal_error (const gchar *message)
{
gimp_eek ("fatal error", message, TRUE);
}
void
gimp_terminate (const gchar *message)
{
gimp_eek ("terminated", message, use_debug_handler);
}
/* private functions */
static void
gimp_third_party_message_log_func (const gchar *log_domain,
GLogLevelFlags flags,
const gchar *message,
gpointer data)
{
Gimp *gimp = data;
if (gimp)
{
/* Whereas all GIMP messages are processed under the same domain,
* we need to keep the log domain information for third party
* messages.
*/
gimp_show_message (gimp, NULL, GIMP_MESSAGE_WARNING,
log_domain, message, NULL);
}
else
{
g_printerr ("%s: %s\n\n", log_domain, message);
}
}
static void
gimp_message_log_func (const gchar *log_domain,
GLogLevelFlags flags,
const gchar *message,
gpointer data)
{
static gint n_traces;
GimpMessageSeverity severity = GIMP_MESSAGE_WARNING;
Gimp *gimp = data;
gchar *trace = NULL;
GimpCoreConfig *config = gimp->config;
gboolean generate_backtrace = FALSE;
g_object_get (G_OBJECT (config),
"generate-backtrace", &generate_backtrace,
NULL);
if (generate_backtrace &&
(flags & (G_LOG_LEVEL_CRITICAL | G_LOG_LEVEL_WARNING)))
{
severity = (flags & G_LOG_LEVEL_CRITICAL) ?
GIMP_MESSAGE_ERROR : GIMP_MESSAGE_WARNING;
if (n_traces < MAX_TRACES)
{
/* Getting debug traces is time-expensive, and worse, some
* critical errors have the bad habit to create more errors
* (the first ones are therefore usually the most useful).
* This is why we keep track of how many times we made traces
* and stop doing them after a while.
* Hence when this happens, critical errors are simply processed as
* lower level errors.
*/
gimp_print_stack_trace (NULL, &trace);
n_traces++;
}
}
if (gimp)
{
gimp_show_message (gimp, NULL, severity,
NULL, message, trace);
}
else
{
g_printerr ("%s: %s\n\n",
gimp_filename_to_utf8 (full_prog_name), message);
if (trace)
g_printerr ("Back trace:\n%s\n\n", trace);
}
if (trace)
g_free (trace);
}
static void
gimp_error_log_func (const gchar *domain,
GLogLevelFlags flags,
const gchar *message,
gpointer data)
{
gimp_fatal_error (message);
}
static void
gimp_eek (const gchar *reason,
const gchar *message,
gboolean use_handler)
{
GimpCoreConfig *config = the_errors_gimp->config;
gboolean generate_backtrace = FALSE;
gboolean eek_handled = FALSE;
/* GIMP has 2 ways to handle termination signals and fatal errors: one
* is the stack trace mode which is set at start as command line
* option --stack-trace-mode, this won't change for the length of the
* session and outputs a trace in terminal; the other is set in
* preferences, outputs a trace in a GUI and can change anytime during
* the session.
* The GUI backtrace has priority if it is set.
*/
g_object_get (G_OBJECT (config),
"generate-backtrace", &generate_backtrace,
NULL);
/* Let's just always output on stdout at least so that there is a
* trace if the rest fails. */
g_printerr ("%s: %s: %s\n", gimp_filename_to_utf8 (full_prog_name),
reason, message);
#if ! defined (G_OS_WIN32) || defined (HAVE_EXCHNDL)
if (use_handler)
{
#ifndef GIMP_CONSOLE_COMPILATION
if (generate_backtrace && ! the_errors_gimp->no_interface)
{
/* If GUI backtrace enabled (it is disabled by default), it
* takes precedence over the command line argument.
*/
#ifdef G_OS_WIN32
const gchar *gimpdebug = "gimp-debug-tool-" GIMP_TOOL_VERSION ".exe";
#elif defined (PLATFORM_OSX)
const gchar *gimpdebug = "gimp-debug-tool-" GIMP_TOOL_VERSION;
#else
const gchar *gimpdebug = LIBEXECDIR "/gimp-debug-tool-" GIMP_TOOL_VERSION;
#endif
gchar *args[7] = { (gchar *) gimpdebug, full_prog_name, NULL,
(gchar *) reason, (gchar *) message,
backtrace_file, NULL };
gchar pid[16];
g_snprintf (pid, 16, "%u", (guint) getpid ());
args[2] = pid;
/* We don't care about any return value. If it fails, too
* bad, we just won't have any stack trace.
* We still need to use the sync() variant because we have
* to keep GIMP up long enough for the debugger to get its
* trace.
*/
#ifdef HAVE_EXCHNDL
/* On Win32, the trace has already been processed by ExcHnl
* and is waiting for us in a text file.
* We just want to spawn the trace GUI and exit GIMP directly.
*/
if (g_file_test (backtrace_file, G_FILE_TEST_IS_REGULAR) &&
g_spawn_async (NULL, args, NULL,
G_SPAWN_SEARCH_PATH | G_SPAWN_STDERR_TO_DEV_NULL | G_SPAWN_STDOUT_TO_DEV_NULL,
NULL, NULL, NULL, NULL))
#else
/* On Unix machines, the spawned process will attach to the
* main GIMP process and will generate the backtrace. So we
* run it as a synced process.
*/
if (g_spawn_sync (NULL, args, NULL,
G_SPAWN_SEARCH_PATH | G_SPAWN_STDERR_TO_DEV_NULL | G_SPAWN_STDOUT_TO_DEV_NULL,
NULL, NULL, NULL, NULL, NULL, NULL))
#endif
eek_handled = TRUE;
}
#endif /* !GIMP_CONSOLE_COMPILATION */
#ifndef G_OS_WIN32
if (! eek_handled)
{
switch (stack_trace_mode)
{
case GIMP_STACK_TRACE_NEVER:
break;
case GIMP_STACK_TRACE_QUERY:
{
sigset_t sigset;
sigemptyset (&sigset);
sigprocmask (SIG_SETMASK, &sigset, NULL);
gimp_on_error_query ();
}
break;
case GIMP_STACK_TRACE_ALWAYS:
{
sigset_t sigset;
sigemptyset (&sigset);
sigprocmask (SIG_SETMASK, &sigset, NULL);
gimp_print_stack_trace (stdout, NULL);
}
break;
default:
break;
}
}
#endif /* ! G_OS_WIN32 */
}
#endif /* ! G_OS_WIN32 || HAVE_EXCHNDL */
#if defined (G_OS_WIN32) && ! defined (GIMP_CONSOLE_COMPILATION)
/* g_on_error_* don't do anything reasonable on Win32. */
if (! eek_handled && ! the_errors_gimp->no_interface)
MessageBox (NULL, g_strdup_printf ("%s: %s", reason, message),
full_prog_name, MB_OK|MB_ICONERROR);
#endif
exit (EXIT_FAILURE);
}
/* In some error cases (e.g. segmentation fault), trying to allocate
* more memory will trigger more segmentation faults and therefore loop
* our error handling (which is just wrong). Therefore printing to a
* file description is an implementation without any memory allocation.
* On the other hand, if trace is not #NULL, a newly-allocated string
* will be returned.
*/
static gboolean
gimp_print_stack_trace (FILE *file,
gchar **trace)
{
gboolean stack_printed = FALSE;
/* This works only on UNIX systems. */
#ifndef G_OS_WIN32
GString *gtrace = NULL;
gchar gimp_pid[16];
pid_t pid;
gchar buffer[256];
ssize_t read_n;
int out_fd[2];
g_snprintf (gimp_pid, 16, "%u", (guint) getpid ());
if (pipe (out_fd) == -1)
{
return FALSE;
}
pid = fork ();
if (pid == 0)
{
/* Child process. */
gchar *args[7] = { "gdb", "-batch", "-ex", "backtrace full",
full_prog_name, NULL, NULL };
args[5] = gimp_pid;
/* Redirect the debugger output. */
dup2 (out_fd[1], STDOUT_FILENO);
close (out_fd[0]);
close (out_fd[1]);
/* Run GDB. */
if (execvp (args[0], args) == -1)
{
/* LLDB as alternative. */
gchar *args_lldb[11] = { "lldb", "--attach-pid", NULL, "--batch",
"--one-line", "bt",
"--one-line-on-crash", "bt",
"--one-line-on-crash", "quit", NULL };
args_lldb[2] = gimp_pid;
execvp (args_lldb[0], args_lldb);
}
_exit (0);
}
else if (pid > 0)
{
/* Main process */
int status;
waitpid (pid, &status, 0);
/* It is important to close the writing side of the pipe, otherwise
* the read() will wait forever without getting the information that
* writing is finished.
*/
close (out_fd[1]);
while ((read_n = read (out_fd[0], buffer, 256)) > 0)
{
/* It's hard to know if the debugger was found since it
* happened in the child. Let's just assume that any output
* means it succeeded.
*/
stack_printed = TRUE;
buffer[read_n] = '\0';
if (file)
g_fprintf (file, "%s", buffer);
if (trace)
{
if (! gtrace)
gtrace = g_string_new (NULL);
g_string_append (gtrace, (const gchar *) buffer);
}
}
close (out_fd[0]);
}
else if (pid == (pid_t) -1)
{
/* Fork failed. */
return FALSE;
}
#ifdef HAVE_EXECINFO_H
if (! stack_printed)
{
/* As a last resort, try using the backtrace() Linux API. It is a bit
* less fancy than gdb or lldb, which is why it is not given priority.
*/
void *bt_buf[100];
char **symbols;
int n_symbols;
int i;
n_symbols = backtrace (bt_buf, 100);
symbols = backtrace_symbols (bt_buf, n_symbols);
if (symbols)
{
stack_printed = TRUE;
for (i = 0; i < n_symbols; i++)
{
if (file)
g_fprintf (file, "%s\n", (const gchar *) symbols[i]);
if (trace)
{
if (! gtrace)
gtrace = g_string_new (NULL);
g_string_append (gtrace,
(const gchar *) symbols[i]);
g_string_append_c (gtrace, '\n');
}
}
free (symbols);
}
}
#endif /* HAVE_EXECINFO_H */
if (trace)
{
if (gtrace)
*trace = g_string_free (gtrace, FALSE);
else
*trace = NULL;
}
#endif /* G_OS_WIN32 */
return stack_printed;
}
/* This is mostly the same as g_on_error_query() except that we use our
* own backtrace function, much more complete.
*/
static void
gimp_on_error_query (void)
{
#ifndef G_OS_WIN32
gchar buf[16];
retry:
g_fprintf (stdout,
"%s (pid:%u): %s: ",
full_prog_name,
(guint) getpid (),
"[E]xit, show [S]tack trace or [P]roceed");
fflush (stdout);
if (isatty(0) && isatty(1))
fgets (buf, 8, stdin);
else
strcpy (buf, "E\n");
if ((buf[0] == 'E' || buf[0] == 'e')
&& buf[1] == '\n')
_exit (0);
else if ((buf[0] == 'P' || buf[0] == 'p')
&& buf[1] == '\n')
return;
else if ((buf[0] == 'S' || buf[0] == 's')
&& buf[1] == '\n')
{
if (! gimp_print_stack_trace (stdout, NULL))
g_fprintf (stderr, "%s\n", "Stack trace not available on your system.");
goto retry;
}
else
goto retry;
#endif
}