| /* Exception (throw catch) mechanism, for GDB, the GNU debugger. |
| |
| Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, |
| 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, |
| 2009, 2010 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 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 "defs.h" |
| #include "exceptions.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" |
| #include "serial.h" |
| #include "gdbthread.h" |
| |
| const struct gdb_exception exception_none = { 0, GDB_NO_ERROR, NULL }; |
| |
| /* 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; |
| /* Jump buffer pointing back at the exception handler. */ |
| EXCEPTIONS_SIGJMP_BUF buf; |
| /* Status buffer belonging to the exception handler. */ |
| 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; |
| |
| EXCEPTIONS_SIGJMP_BUF * |
| exceptions_state_mc_init (struct ui_out *func_uiout, |
| 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 = 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. */ |
| new_catcher->saved_cleanup_chain = save_cleanups (); |
| |
| /* Push this new catcher on the top. */ |
| new_catcher->prev = current_catcher; |
| current_catcher = new_catcher; |
| new_catcher->state = CATCHER_CREATED; |
| |
| return &new_catcher->buf; |
| } |
| |
| static void |
| 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. */ |
| |
| restore_cleanups (old_catcher->saved_cleanup_chain); |
| |
| uiout = old_catcher->saved_uiout; |
| |
| xfree (old_catcher); |
| } |
| |
| /* Catcher state machine. Returns non-zero if the m/c should be run |
| again, zero if it should abort. */ |
| |
| static int |
| exceptions_state_mc (enum catcher_action action) |
| { |
| switch (current_catcher->state) |
| { |
| 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) |
| { |
| 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: |
| { |
| struct gdb_exception exception = *current_catcher->exception; |
| |
| if (current_catcher->mask & RETURN_MASK (exception.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 (exception); |
| } |
| default: |
| internal_error (__FILE__, __LINE__, _("bad state")); |
| } |
| default: |
| internal_error (__FILE__, __LINE__, _("bad switch")); |
| } |
| } |
| |
| int |
| exceptions_state_mc_action_iter (void) |
| { |
| return exceptions_state_mc (CATCH_ITER); |
| } |
| |
| int |
| exceptions_state_mc_action_iter_1 (void) |
| { |
| return exceptions_state_mc (CATCH_ITER_1); |
| } |
| |
| /* Return EXCEPTION to the nearest containing catch_errors(). */ |
| |
| void |
| throw_exception (struct gdb_exception exception) |
| { |
| struct thread_info *tp = NULL; |
| |
| quit_flag = 0; |
| immediate_quit = 0; |
| |
| if (!ptid_equal (inferior_ptid, null_ptid)) |
| tp = find_thread_ptid (inferior_ptid); |
| |
| /* 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). */ |
| if (tp != NULL) |
| bpstat_clear_actions (tp->stop_bpstat); /* Clear queued breakpoint commands */ |
| |
| disable_current_display (); |
| 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. */ |
| exceptions_state_mc (CATCH_THROWING); |
| *current_catcher->exception = exception; |
| EXCEPTIONS_SIGLONGJMP (current_catcher->buf, exception.reason); |
| } |
| |
| static char *last_message; |
| |
| void |
| deprecated_throw_reason (enum return_reason reason) |
| { |
| struct gdb_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) |
| { |
| struct serial *gdb_stdout_serial; |
| |
| if (deprecated_error_begin_hook) |
| deprecated_error_begin_hook (); |
| target_terminal_ours (); |
| |
| /* 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): */ |
| |
| /* 1. The _filtered buffer. */ |
| wrap_here (""); |
| |
| /* 2. The stdio buffer. */ |
| gdb_flush (gdb_stdout); |
| gdb_flush (gdb_stderr); |
| |
| /* 3. The system-level buffer. */ |
| gdb_stdout_serial = serial_fdopen (1); |
| 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 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'); |
| if (end == NULL) |
| fputs_filtered (start, file); |
| else |
| { |
| 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.")); |
| } |
| } |
| |
| void |
| exception_print (struct ui_file *file, struct gdb_exception e) |
| { |
| if (e.reason < 0 && e.message != NULL) |
| { |
| print_flush (); |
| print_exception (file, e); |
| } |
| } |
| |
| void |
| exception_fprintf (struct ui_file *file, struct gdb_exception e, |
| const char *prefix, ...) |
| { |
| 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); |
| } |
| } |
| |
| static void |
| print_any_exception (struct ui_file *file, const char *prefix, |
| struct gdb_exception e) |
| { |
| if (e.reason < 0 && e.message != NULL) |
| { |
| target_terminal_ours (); |
| wrap_here (""); /* Force out any buffered output */ |
| gdb_flush (gdb_stdout); |
| annotate_error_begin (); |
| |
| /* Print the prefix. */ |
| if (prefix != NULL && prefix[0] != '\0') |
| fputs_filtered (prefix, file); |
| print_exception (file, e); |
| } |
| } |
| |
| static void ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (3, 0) |
| throw_it (enum return_reason reason, enum errors error, const char *fmt, |
| va_list ap) |
| { |
| struct gdb_exception e; |
| char *new_message; |
| |
| /* Save the message. Create the new message before deleting the |
| old, the new message may include the old message text. */ |
| new_message = xstrvprintf (fmt, ap); |
| xfree (last_message); |
| last_message = new_message; |
| |
| /* Create the exception. */ |
| e.reason = reason; |
| e.error = error; |
| e.message = last_message; |
| |
| /* Throw the exception. */ |
| throw_exception (e); |
| } |
| |
| void |
| throw_verror (enum errors error, const char *fmt, va_list ap) |
| { |
| throw_it (RETURN_ERROR, error, fmt, ap); |
| } |
| |
| void |
| throw_vfatal (const char *fmt, va_list ap) |
| { |
| throw_it (RETURN_QUIT, GDB_NO_ERROR, fmt, ap); |
| } |
| |
| 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(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. */ |
| |
| /* MAYBE: cagney/1999-11-05: catch_errors() in conjunction with |
| error() et.al. could maintain a set of flags that indicate the 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. */ |
| |
| int |
| catch_exceptions (struct ui_out *uiout, |
| catch_exceptions_ftype *func, |
| void *func_args, |
| return_mask mask) |
| { |
| return catch_exceptions_with_msg (uiout, func, func_args, NULL, mask); |
| } |
| |
| struct gdb_exception |
| catch_exception (struct ui_out *uiout, |
| catch_exception_ftype *func, |
| void *func_args, |
| return_mask mask) |
| { |
| volatile struct gdb_exception exception; |
| |
| TRY_CATCH (exception, mask) |
| { |
| (*func) (uiout, func_args); |
| } |
| return exception; |
| } |
| |
| int |
| catch_exceptions_with_msg (struct ui_out *uiout, |
| catch_exceptions_ftype *func, |
| void *func_args, |
| char **gdberrmsg, |
| return_mask mask) |
| { |
| volatile struct gdb_exception exception; |
| volatile int val = 0; |
| |
| TRY_CATCH (exception, mask) |
| { |
| val = (*func) (uiout, func_args); |
| } |
| print_any_exception (gdb_stderr, NULL, exception); |
| gdb_assert (val >= 0); |
| 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) |
| { |
| volatile int val = 0; |
| volatile struct gdb_exception exception; |
| |
| TRY_CATCH (exception, mask) |
| { |
| val = func (func_args); |
| } |
| print_any_exception (gdb_stderr, errstring, exception); |
| if (exception.reason != 0) |
| return 0; |
| return val; |
| } |
| |
| int |
| catch_command_errors (catch_command_errors_ftype * command, |
| char *arg, int from_tty, return_mask mask) |
| { |
| 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; |
| } |