/* Exception (throw catch) mechanism, for GDB, the GNU debugger.
- Copyright 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
- 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free
- Software Foundation, Inc.
+ Copyright (C) 1986-2014 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 2 of the License, or
+ 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,
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, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "exceptions.h"
#include "annotate.h"
#include "ui-out.h"
#include "gdb_assert.h"
-#include "gdb_string.h"
+#include <string.h>
#include "serial.h"
+#include "gdbthread.h"
-const struct exception exception_none = { 0, NO_ERROR, NULL };
+const struct gdb_exception exception_none = { 0, GDB_NO_ERROR, NULL };
/* Possible catcher states. */
enum catcher_state {
/* Jump buffer pointing back at the exception handler. */
EXCEPTIONS_SIGJMP_BUF buf;
/* Status buffer belonging to the exception handler. */
- volatile struct exception *exception;
+ volatile struct gdb_exception *exception;
/* Saved/current state. */
int mask;
- struct ui_out *saved_uiout;
struct cleanup *saved_cleanup_chain;
/* Back link. */
struct catcher *prev;
/* Where to go for throw_exception(). */
static struct catcher *current_catcher;
+/* Return length of current_catcher list. */
+
+static int
+catcher_list_size (void)
+{
+ int size;
+ struct catcher *catcher;
+
+ for (size = 0, catcher = current_catcher;
+ catcher != NULL;
+ catcher = catcher->prev)
+ ++size;
+
+ return size;
+}
+
EXCEPTIONS_SIGJMP_BUF *
-exceptions_state_mc_init (struct ui_out *func_uiout,
- volatile struct exception *exception,
+exceptions_state_mc_init (volatile struct gdb_exception *exception,
return_mask mask)
{
struct catcher *new_catcher = XZALLOC (struct catcher);
/* Start with no exception, save it's address. */
exception->reason = 0;
- exception->error = NO_ERROR;
+ exception->error = GDB_NO_ERROR;
exception->message = NULL;
new_catcher->exception = exception;
new_catcher->mask = mask;
- /* Override the global ``struct ui_out'' builder. */
- new_catcher->saved_uiout = uiout;
- uiout = func_uiout;
-
/* Prevent error/quit during FUNC from calling cleanups established
- prior to here. */
+ prior to here. */
new_catcher->saved_cleanup_chain = save_cleanups ();
/* Push this new catcher on the top. */
catcher_pop (void)
{
struct catcher *old_catcher = current_catcher;
+
current_catcher = old_catcher->prev;
/* Restore the cleanup chain, the error/quit messages, and the uiout
- builder, to their original states. */
+ builder, to their original states. */
restore_cleanups (old_catcher->saved_cleanup_chain);
- uiout = old_catcher->saved_uiout;
-
xfree (old_catcher);
}
{
case CATCH_ITER:
{
- struct exception exception = *current_catcher->exception;
+ struct gdb_exception exception = *current_catcher->exception;
+
if (current_catcher->mask & RETURN_MASK (exception.reason))
{
/* Exit normally if this catcher can handle this
}
/* The caller didn't request that the event be caught,
relay the event to the next containing
- catch_errors(). */
+ catch_errors(). */
catcher_pop ();
throw_exception (exception);
}
/* Return EXCEPTION to the nearest containing catch_errors(). */
-NORETURN void
-throw_exception (struct exception exception)
+void
+throw_exception (struct gdb_exception exception)
{
- quit_flag = 0;
+ clear_quit_flag ();
immediate_quit = 0;
- /* Perhaps it would be cleaner to do this via the cleanup chain (not sure
- I can think of a reason why that is vital, though). */
- bpstat_clear_actions (stop_bpstat); /* Clear queued breakpoint commands */
-
- disable_current_display ();
- do_cleanups (ALL_CLEANUPS);
- if (target_can_async_p () && !target_executing)
- do_exec_cleanups (ALL_CLEANUPS);
- if (sync_execution)
- do_exec_error_cleanups (ALL_CLEANUPS);
+ do_cleanups (all_cleanups ());
/* Jump to the containing catch_errors() call, communicating REASON
to that call via setjmp's return value. Note that REASON can't
- be zero, by definition in defs.h. */
+ be zero, by definition in defs.h. */
exceptions_state_mc (CATCH_THROWING);
*current_catcher->exception = exception;
EXCEPTIONS_SIGLONGJMP (current_catcher->buf, exception.reason);
}
-static char *last_message;
-
-NORETURN void
-deprecated_throw_reason (enum return_reason reason)
-{
- struct exception exception;
- memset (&exception, 0, sizeof exception);
-
- exception.reason = reason;
- switch (reason)
- {
- case RETURN_QUIT:
- break;
- case RETURN_ERROR:
- exception.error = GENERIC_ERROR;
- break;
- default:
- internal_error (__FILE__, __LINE__, _("bad switch"));
- }
-
- throw_exception (exception);
-}
-
static void
print_flush (void)
{
/* 3. The system-level buffer. */
gdb_stdout_serial = serial_fdopen (1);
- serial_drain_output (gdb_stdout_serial);
- serial_un_fdopen (gdb_stdout_serial);
+ if (gdb_stdout_serial)
+ {
+ serial_drain_output (gdb_stdout_serial);
+ serial_un_fdopen (gdb_stdout_serial);
+ }
annotate_error_begin ();
}
static void
-print_exception (struct ui_file *file, struct exception e)
+print_exception (struct ui_file *file, struct gdb_exception e)
{
/* KLUGE: cagney/2005-01-13: Write the string out one line at a time
as that way the MI's behavior is preserved. */
const char *start;
const char *end;
+
for (start = e.message; start != NULL; start = end)
{
end = strchr (start, '\n');
}
void
-exception_print (struct ui_file *file, struct exception e)
+exception_print (struct ui_file *file, struct gdb_exception e)
{
if (e.reason < 0 && e.message != NULL)
{
}
void
-exception_fprintf (struct ui_file *file, struct exception e,
+exception_fprintf (struct ui_file *file, struct gdb_exception e,
const char *prefix, ...)
{
if (e.reason < 0 && e.message != NULL)
}
}
-void
+static void
print_any_exception (struct ui_file *file, const char *prefix,
- struct exception e)
+ struct gdb_exception e)
{
if (e.reason < 0 && e.message != NULL)
{
target_terminal_ours ();
- wrap_here (""); /* Force out any buffered output */
+ wrap_here (""); /* Force out any buffered output. */
gdb_flush (gdb_stdout);
annotate_error_begin ();
}
}
-NORETURN static void
-throw_it (enum return_reason reason, enum errors error, const char *fmt,
- va_list ap) ATTR_NORETURN;
-NORETURN static void
+/* A stack of exception messages.
+ This is needed to handle nested calls to throw_it: we don't want to
+ xfree space for a message before it's used.
+ This can happen if we throw an exception during a cleanup:
+ An outer TRY_CATCH may have an exception message it wants to print,
+ but while doing cleanups further calls to throw_it are made.
+
+ This is indexed by the size of the current_catcher list.
+ It is a dynamically allocated array so that we don't care how deeply
+ GDB nests its TRY_CATCHs. */
+static char **exception_messages;
+
+/* The number of currently allocated entries in exception_messages. */
+static int exception_messages_size;
+
+static void ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (3, 0)
throw_it (enum return_reason reason, enum errors error, const char *fmt,
va_list ap)
{
- struct exception e;
+ struct gdb_exception e;
char *new_message;
+ int depth = catcher_list_size ();
+
+ gdb_assert (depth > 0);
- /* Save the message. Create the new message before deleting the
- old, the new message may include the old message text. */
+ /* Note: The new message may use an old message's text. */
new_message = xstrvprintf (fmt, ap);
- xfree (last_message);
- last_message = new_message;
+
+ if (depth > exception_messages_size)
+ {
+ int old_size = exception_messages_size;
+
+ exception_messages_size = depth + 10;
+ exception_messages = (char **) xrealloc (exception_messages,
+ exception_messages_size
+ * sizeof (char *));
+ memset (exception_messages + old_size, 0,
+ (exception_messages_size - old_size) * sizeof (char *));
+ }
+
+ xfree (exception_messages[depth - 1]);
+ exception_messages[depth - 1] = new_message;
/* Create the exception. */
e.reason = reason;
e.error = error;
- e.message = last_message;
+ e.message = new_message;
/* Throw the exception. */
throw_exception (e);
}
-NORETURN void
+void
throw_verror (enum errors error, const char *fmt, va_list ap)
{
throw_it (RETURN_ERROR, error, fmt, ap);
}
-NORETURN void
+void
throw_vfatal (const char *fmt, va_list ap)
{
- throw_it (RETURN_QUIT, NO_ERROR, fmt, ap);
+ throw_it (RETURN_QUIT, GDB_NO_ERROR, fmt, ap);
}
-NORETURN void
+void
throw_error (enum errors error, const char *fmt, ...)
{
va_list args;
+
va_start (args, fmt);
throw_it (RETURN_ERROR, error, fmt, args);
va_end (args);
}
-/* Call FUNC() with args FUNC_UIOUT and FUNC_ARGS, catching any
- errors. Set FUNC_CAUGHT to an ``enum return_reason'' if the
- function is aborted (using throw_exception() or zero if the
- function returns normally. Set FUNC_VAL to the value returned by
- the function or 0 if the function was aborted.
+/* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
+ handler. If an exception (enum return_reason) is thrown using
+ throw_exception() than all cleanups installed since
+ catch_exceptions() was entered are invoked, the (-ve) exception
+ value is then returned by catch_exceptions. If FUNC() returns
+ normally (with a positive or zero return value) then that value is
+ returned by catch_exceptions(). It is an internal_error() for
+ FUNC() to return a negative value.
+
+ See exceptions.h for further usage details.
Must not be called with immediate_quit in effect (bad things might
happen, say we got a signal in the middle of a memcpy to quit_return).
This is an OK restriction; with very few exceptions immediate_quit can
- be replaced by judicious use of QUIT.
-
- MASK specifies what to catch; it is normally set to
- RETURN_MASK_ALL, if for no other reason than that the code which
- calls catch_errors might not be set up to deal with a quit which
- isn't caught. But if the code can deal with it, it generally
- should be RETURN_MASK_ERROR, unless for some reason it is more
- useful to abort only the portion of the operation inside the
- catch_errors. Note that quit should return to the command line
- fairly quickly, even if some further processing is being done. */
+ be replaced by judicious use of QUIT. */
/* MAYBE: cagney/1999-11-05: catch_errors() in conjunction with
- error() et.al. could maintain a set of flags that indicate the the
+ error() et al. could maintain a set of flags that indicate the
current state of each of the longjmp buffers. This would give the
longjmp code the chance to detect a longjmp botch (before it gets
to longjmperror()). Prior to 1999-11-05 this wasn't possible as
code also randomly used a SET_TOP_LEVEL macro that directly
- initialize the longjmp buffers. */
-
-/* MAYBE: cagney/1999-11-05: Should the catch_errors and cleanups code
- be consolidated into a single file instead of being distributed
- between utils.c and top.c? */
+ initialized the longjmp buffers. */
int
catch_exceptions (struct ui_out *uiout,
return catch_exceptions_with_msg (uiout, func, func_args, NULL, mask);
}
-struct exception
-catch_exception (struct ui_out *uiout,
- catch_exception_ftype *func,
- void *func_args,
- return_mask mask)
-{
- volatile struct exception exception;
- TRY_CATCH (exception, mask)
- {
- (*func) (uiout, func_args);
- }
- return exception;
-}
-
int
-catch_exceptions_with_msg (struct ui_out *uiout,
+catch_exceptions_with_msg (struct ui_out *func_uiout,
catch_exceptions_ftype *func,
void *func_args,
char **gdberrmsg,
return_mask mask)
{
- volatile struct exception exception;
+ volatile struct gdb_exception exception;
volatile int val = 0;
- TRY_CATCH (exception, mask)
+ struct ui_out *saved_uiout;
+
+ /* Save and override the global ``struct ui_out'' builder. */
+ saved_uiout = current_uiout;
+ current_uiout = func_uiout;
+
+ TRY_CATCH (exception, RETURN_MASK_ALL)
+ {
+ val = (*func) (current_uiout, func_args);
+ }
+
+ /* Restore the global builder. */
+ current_uiout = saved_uiout;
+
+ if (exception.reason < 0 && (mask & RETURN_MASK (exception.reason)) == 0)
{
- val = (*func) (uiout, func_args);
+ /* The caller didn't request that the event be caught.
+ Rethrow. */
+ throw_exception (exception);
}
+
print_any_exception (gdb_stderr, NULL, exception);
gdb_assert (val >= 0);
gdb_assert (exception.reason <= 0);
return val;
}
+/* This function is superseded by catch_exceptions(). */
+
int
catch_errors (catch_errors_ftype *func, void *func_args, char *errstring,
return_mask mask)
{
volatile int val = 0;
- volatile struct exception exception;
- TRY_CATCH (exception, mask)
+ volatile struct gdb_exception exception;
+ struct ui_out *saved_uiout;
+
+ /* Save the global ``struct ui_out'' builder. */
+ saved_uiout = current_uiout;
+
+ TRY_CATCH (exception, RETURN_MASK_ALL)
{
val = func (func_args);
}
+
+ /* Restore the global builder. */
+ current_uiout = saved_uiout;
+
+ if (exception.reason < 0 && (mask & RETURN_MASK (exception.reason)) == 0)
+ {
+ /* The caller didn't request that the event be caught.
+ Rethrow. */
+ throw_exception (exception);
+ }
+
print_any_exception (gdb_stderr, errstring, exception);
if (exception.reason != 0)
return 0;
}
int
-catch_command_errors (catch_command_errors_ftype * command,
+catch_command_errors (catch_command_errors_ftype *command,
char *arg, int from_tty, return_mask mask)
{
- volatile struct exception e;
+ volatile struct gdb_exception e;
+
+ TRY_CATCH (e, mask)
+ {
+ command (arg, from_tty);
+ }
+ print_any_exception (gdb_stderr, NULL, e);
+ if (e.reason < 0)
+ return 0;
+ return 1;
+}
+
+int
+catch_command_errors_const (catch_command_errors_const_ftype *command,
+ const char *arg, int from_tty, return_mask mask)
+{
+ volatile struct gdb_exception e;
+
TRY_CATCH (e, mask)
{
command (arg, from_tty);