/* 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 Free Software
- Foundation, Inc.
+ Copyright (C) 1986-2017 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 <setjmp.h>
#include "breakpoint.h"
#include "target.h"
#include "inferior.h"
#include "annotate.h"
#include "ui-out.h"
-#include "gdb_assert.h"
-#include "gdb_string.h"
-
-/* One should use catch_errors rather than manipulating these
- directly. */
-#if defined(HAVE_SIGSETJMP)
-#define SIGJMP_BUF sigjmp_buf
-#define SIGSETJMP(buf) sigsetjmp((buf), 1)
-#define SIGLONGJMP(buf,val) siglongjmp((buf), (val))
-#else
-#define SIGJMP_BUF jmp_buf
-#define SIGSETJMP(buf) setjmp(buf)
-#define SIGLONGJMP(buf,val) longjmp((buf), (val))
-#endif
-
-/* Possible catcher states. */
-enum catcher_state {
- /* Initial state, a new catcher has just been created. */
- CATCHER_CREATED,
- /* The catch code is running. */
- CATCHER_RUNNING,
- CATCHER_RUNNING_1,
- /* The catch code threw an exception. */
- CATCHER_ABORTING
-};
-
-/* Possible catcher actions. */
-enum catcher_action {
- CATCH_ITER,
- CATCH_ITER_1,
- CATCH_THROWING
-};
-
-struct catcher
-{
- enum catcher_state state;
- /* Scratch variables used when transitioning a state. */
- SIGJMP_BUF buf;
- int reason;
- int val;
- /* Saved/current state. */
- int mask;
- char *saved_error_pre_print;
- char *saved_quit_pre_print;
- struct ui_out *saved_uiout;
- struct cleanup *saved_cleanup_chain;
- char **gdberrmsg;
- /* Back link. */
- struct catcher *prev;
-};
-
-/* Where to go for throw_exception(). */
-static struct catcher *current_catcher;
-
-static SIGJMP_BUF *
-catcher_init (struct ui_out *func_uiout,
- char *errstring,
- char **gdberrmsg,
- return_mask mask)
-{
- struct catcher *new_catcher = XZALLOC (struct catcher);
-
- new_catcher->gdberrmsg = gdberrmsg;
- new_catcher->mask = mask;
-
- /* Override error/quit messages during FUNC. */
- new_catcher->saved_error_pre_print = error_pre_print;
- new_catcher->saved_quit_pre_print = quit_pre_print;
- if (mask & RETURN_MASK_ERROR)
- error_pre_print = errstring;
- if (mask & RETURN_MASK_QUIT)
- quit_pre_print = errstring;
+#include "serial.h"
+#include "gdbthread.h"
+#include "top.h"
- /* 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. */
- new_catcher->saved_cleanup_chain = save_cleanups ();
+static void
+print_flush (void)
+{
+ struct ui *ui = current_ui;
+ struct serial *gdb_stdout_serial;
+ struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
- /* Push this new catcher on the top. */
- new_catcher->prev = current_catcher;
- current_catcher = new_catcher;
- new_catcher->state = CATCHER_CREATED;
+ if (deprecated_error_begin_hook)
+ deprecated_error_begin_hook ();
- return &new_catcher->buf;
-}
+ if (target_supports_terminal_ours ())
+ {
+ make_cleanup_restore_target_terminal ();
+ target_terminal_ours_for_output ();
+ }
-static void
-catcher_pop (void)
-{
- struct catcher *old_catcher = current_catcher;
- current_catcher = old_catcher->prev;
+ /* We want all output to appear now, before we print the error. We
+ have 3 levels of buffering we have to flush (it's possible that
+ some of these should be changed to flush the lower-level ones
+ too): */
- /* Restore the cleanup chain, the error/quit messages, and the uiout
- builder, to their original states. */
+ /* 1. The _filtered buffer. */
+ if (filtered_printing_initialized ())
+ wrap_here ("");
- restore_cleanups (old_catcher->saved_cleanup_chain);
+ /* 2. The stdio buffer. */
+ gdb_flush (gdb_stdout);
+ gdb_flush (gdb_stderr);
- uiout = old_catcher->saved_uiout;
+ /* 3. The system-level buffer. */
+ gdb_stdout_serial = serial_fdopen (fileno (ui->outstream));
+ if (gdb_stdout_serial)
+ {
+ serial_drain_output (gdb_stdout_serial);
+ serial_un_fdopen (gdb_stdout_serial);
+ }
- quit_pre_print = old_catcher->saved_quit_pre_print;
- error_pre_print = old_catcher->saved_error_pre_print;
+ annotate_error_begin ();
- xfree (old_catcher);
+ do_cleanups (old_chain);
}
-/* Catcher state machine. Returns non-zero if the m/c should be run
- again, zero if it should abort. */
-
-int
-catcher_state_machine (enum catcher_action action)
+static void
+print_exception (struct ui_file *file, struct gdb_exception e)
{
- switch (current_catcher->state)
+ /* 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)
{
- case CATCHER_CREATED:
- switch (action)
- {
- case CATCH_ITER:
- /* Allow the code to run the catcher. */
- current_catcher->state = CATCHER_RUNNING;
- return 1;
- default:
- internal_error (__FILE__, __LINE__, "bad state");
- }
- case CATCHER_RUNNING:
- switch (action)
- {
- case CATCH_ITER:
- /* No error/quit has occured. Just clean up. */
- catcher_pop ();
- return 0;
- case CATCH_ITER_1:
- current_catcher->state = CATCHER_RUNNING_1;
- return 1;
- case CATCH_THROWING:
- current_catcher->state = CATCHER_ABORTING;
- /* See also throw_exception. */
- return 1;
- default:
- internal_error (__FILE__, __LINE__, "bad switch");
- }
- case CATCHER_RUNNING_1:
- switch (action)
+ end = strchr (start, '\n');
+ if (end == NULL)
+ fputs_filtered (start, file);
+ else
{
- case CATCH_ITER:
- /* The did a "break" from the inner while loop. */
- catcher_pop ();
- return 0;
- case CATCH_ITER_1:
- current_catcher->state = CATCHER_RUNNING;
- return 0;
- case CATCH_THROWING:
- current_catcher->state = CATCHER_ABORTING;
- /* See also throw_exception. */
- return 1;
- default:
- internal_error (__FILE__, __LINE__, "bad switch");
- }
- case CATCHER_ABORTING:
- switch (action)
- {
- case CATCH_ITER:
- {
- int reason = current_catcher->reason;
- /* If caller wants a copy of the low-level error message,
- make one. This is used in the case of a silent error
- whereby the caller may optionally want to issue the
- message. */
- if (current_catcher->gdberrmsg != NULL)
- *(current_catcher->gdberrmsg) = error_last_message ();
- if (current_catcher->mask & RETURN_MASK (reason))
- {
- /* Exit normally if this catcher can handle this
- exception. The caller analyses the func return
- values. */
- catcher_pop ();
- return 0;
- }
- /* The caller didn't request that the event be caught,
- relay the event to the next containing
- catch_errors(). */
- catcher_pop ();
- throw_exception (reason);
- }
- default:
- internal_error (__FILE__, __LINE__, "bad state");
+ end++;
+ ui_file_write (file, start, end - start);
}
+ }
+ fprintf_filtered (file, "\n");
+
+ /* Now append the annotation. */
+ switch (e.reason)
+ {
+ case RETURN_QUIT:
+ annotate_quit ();
+ break;
+ case RETURN_ERROR:
+ /* Assume that these are all errors. */
+ annotate_error ();
+ break;
default:
- internal_error (__FILE__, __LINE__, "bad switch");
+ internal_error (__FILE__, __LINE__, _("Bad switch."));
}
}
-/* Return for reason REASON to the nearest containing catch_errors(). */
+void
+exception_print (struct ui_file *file, struct gdb_exception e)
+{
+ if (e.reason < 0 && e.message != NULL)
+ {
+ print_flush ();
+ print_exception (file, e);
+ }
+}
-NORETURN void
-throw_exception (enum return_reason reason)
+void
+exception_fprintf (struct ui_file *file, struct gdb_exception e,
+ const char *prefix, ...)
{
- quit_flag = 0;
- 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);
-
- if (annotation_level > 1)
- switch (reason)
- {
- case RETURN_QUIT:
- annotate_quit ();
- break;
- case RETURN_ERROR:
- annotate_error ();
- break;
- }
-
- /* 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. */
- catcher_state_machine (CATCH_THROWING);
- current_catcher->reason = reason;
- SIGLONGJMP (current_catcher->buf, current_catcher->reason);
+ if (e.reason < 0 && e.message != NULL)
+ {
+ va_list args;
+
+ print_flush ();
+
+ /* Print the prefix. */
+ va_start (args, prefix);
+ vfprintf_filtered (file, prefix, args);
+ va_end (args);
+
+ print_exception (file, e);
+ }
}
-/* 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.
-
- 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. */
+/* 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. */
/* 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,
catch_exceptions_ftype *func,
void *func_args,
- char *errstring,
return_mask mask)
{
- return catch_exceptions_with_msg (uiout, func, func_args, errstring,
- NULL, mask);
+ return catch_exceptions_with_msg (uiout, func, func_args, NULL, mask);
}
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 *errstring,
char **gdberrmsg,
return_mask mask)
{
- int val = 0;
- enum return_reason caught;
- SIGJMP_BUF *catch;
- catch = catcher_init (uiout, errstring, gdberrmsg, mask);
- for (caught = SIGSETJMP ((*catch));
- catcher_state_machine (CATCH_ITER);)
- val = (*func) (uiout, func_args);
+ struct gdb_exception exception = exception_none;
+ volatile int val = 0;
+ struct ui_out *saved_uiout;
+
+ /* Save and override the global ``struct ui_out'' builder. */
+ saved_uiout = current_uiout;
+ current_uiout = func_uiout;
+
+ TRY
+ {
+ val = (*func) (current_uiout, func_args);
+ }
+ CATCH (ex, RETURN_MASK_ALL)
+ {
+ exception = ex;
+ }
+ END_CATCH
+
+ /* 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);
+ }
+
+ exception_print (gdb_stderr, exception);
gdb_assert (val >= 0);
- gdb_assert (caught <= 0);
- if (caught < 0)
- return caught;
+ gdb_assert (exception.reason <= 0);
+ if (exception.reason < 0)
+ {
+ /* If caller wants a copy of the low-level error message, make
+ one. This is used in the case of a silent error whereby the
+ caller may optionally want to issue the message. */
+ if (gdberrmsg != NULL)
+ {
+ if (exception.message != NULL)
+ *gdberrmsg = xstrdup (exception.message);
+ else
+ *gdberrmsg = NULL;
+ }
+ return exception.reason;
+ }
return val;
}
+/* This function is superseded by catch_exceptions(). */
+
int
-catch_errors (catch_errors_ftype *func, void *func_args, char *errstring,
- return_mask mask)
+catch_errors (catch_errors_ftype *func, void *func_args,
+ const char *errstring, return_mask mask)
{
- int val = 0;
- enum return_reason caught;
- SIGJMP_BUF *catch;
- catch = catcher_init (uiout, errstring, NULL, mask);
- /* This illustrates how it is possible to nest the mechanism and
- hence catch "break". Of course this doesn't address the need to
- also catch "return". */
- for (caught = SIGSETJMP ((*catch)); catcher_state_machine (CATCH_ITER);)
- for (; catcher_state_machine (CATCH_ITER_1);)
- {
- val = func (func_args);
- break;
- }
- if (caught != 0)
+ struct gdb_exception exception = exception_none;
+ volatile int val = 0;
+ struct ui_out *saved_uiout;
+
+ /* Save the global ``struct ui_out'' builder. */
+ saved_uiout = current_uiout;
+
+ TRY
+ {
+ val = func (func_args);
+ }
+ CATCH (ex, RETURN_MASK_ALL)
+ {
+ exception = ex;
+ }
+ END_CATCH
+
+ /* 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);
+ }
+
+ exception_fprintf (gdb_stderr, exception, "%s", errstring);
+ if (exception.reason != 0)
return 0;
return val;
}
-struct captured_command_args
- {
- catch_command_errors_ftype *command;
- char *arg;
- int from_tty;
- };
-
-static int
-do_captured_command (void *data)
-{
- struct captured_command_args *context = data;
- context->command (context->arg, context->from_tty);
- /* FIXME: cagney/1999-11-07: Technically this do_cleanups() call
- isn't needed. Instead an assertion check could be made that
- simply confirmed that the called function correctly cleaned up
- after itself. Unfortunately, old code (prior to 1999-11-04) in
- main.c was calling SET_TOP_LEVEL(), calling the command function,
- and then *always* calling do_cleanups(). For the moment we
- remain ``bug compatible'' with that old code.. */
- do_cleanups (ALL_CLEANUPS);
- return 1;
-}
+/* See exceptions.h. */
int
-catch_command_errors (catch_command_errors_ftype * command,
- char *arg, int from_tty, return_mask mask)
+exception_print_same (struct gdb_exception e1, struct gdb_exception e2)
{
- struct captured_command_args args;
- args.command = command;
- args.arg = arg;
- args.from_tty = from_tty;
- return catch_errors (do_captured_command, &args, "", mask);
+ const char *msg1 = e1.message;
+ const char *msg2 = e2.message;
+
+ if (msg1 == NULL)
+ msg1 = "";
+ if (msg2 == NULL)
+ msg2 = "";
+
+ return (e1.reason == e2.reason
+ && e1.error == e2.error
+ && strcmp (msg1, msg2) == 0);
}
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