/* 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) 1986-2013 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"
+#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
+};
-/* 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
+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 cleanup *saved_cleanup_chain;
+ /* Back link. */
+ struct catcher *prev;
+};
/* Where to go for throw_exception(). */
-static SIGJMP_BUF *catch_return;
+static struct catcher *current_catcher;
-/* Return for reason REASON to the nearest containing catch_errors(). */
+/* Return length of current_catcher list. */
-NORETURN void
-throw_exception (enum return_reason reason)
+static int
+catcher_list_size (void)
{
- quit_flag = 0;
- immediate_quit = 0;
+ int size;
+ struct catcher *catcher;
- /* 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;
- }
+ for (size = 0, catcher = current_catcher;
+ catcher != NULL;
+ catcher = catcher->prev)
+ ++size;
- /* 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. */
+ return size;
+}
+
+EXCEPTIONS_SIGJMP_BUF *
+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 = GDB_NO_ERROR;
+ exception->message = NULL;
+ new_catcher->exception = exception;
+
+ new_catcher->mask = mask;
- (NORETURN void) SIGLONGJMP (*catch_return, (int) reason);
+ /* 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;
}
-/* 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.
+static void
+catcher_pop (void)
+{
+ struct catcher *old_catcher = current_catcher;
+
+ current_catcher = old_catcher->prev;
- 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.
+ /* Restore the cleanup chain, the error/quit messages, and the uiout
+ builder, to their original states. */
- 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. */
+ restore_cleanups (old_catcher->saved_cleanup_chain);
-/* 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. */
+ xfree (old_catcher);
+}
-/* 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? */
+/* 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)
+{
+ clear_quit_flag ();
+ immediate_quit = 0;
+
+ 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 void
-catcher (catch_exceptions_ftype *func,
- struct ui_out *func_uiout,
- void *func_args,
- int *func_val,
- enum return_reason *func_caught,
- char *errstring,
- char **gdberrmsg,
- return_mask mask)
+print_flush (void)
{
- SIGJMP_BUF *saved_catch;
- SIGJMP_BUF catch;
- struct cleanup *saved_cleanup_chain;
- char *saved_error_pre_print;
- char *saved_quit_pre_print;
- struct ui_out *saved_uiout;
+ struct serial *gdb_stdout_serial;
- /* Return value from SIGSETJMP(): enum return_reason if error or
- quit caught, 0 otherwise. */
- int caught;
+ if (deprecated_error_begin_hook)
+ deprecated_error_begin_hook ();
+ target_terminal_ours ();
- /* Return value from FUNC(): Hopefully non-zero. Explicitly set to
- zero if an error quit was caught. */
- int val;
+ /* 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): */
- /* Override error/quit messages during FUNC. */
+ /* 1. The _filtered buffer. */
+ wrap_here ("");
- saved_error_pre_print = error_pre_print;
- saved_quit_pre_print = quit_pre_print;
+ /* 2. The stdio buffer. */
+ gdb_flush (gdb_stdout);
+ gdb_flush (gdb_stderr);
- if (mask & RETURN_MASK_ERROR)
- error_pre_print = errstring;
- if (mask & RETURN_MASK_QUIT)
- quit_pre_print = errstring;
+ /* 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);
+ }
- /* Override the global ``struct ui_out'' builder. */
+ annotate_error_begin ();
+}
- saved_uiout = uiout;
- uiout = func_uiout;
+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;
- /* Prevent error/quit during FUNC from calling cleanups established
- prior to here. */
+ 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."));
+ }
+}
- saved_cleanup_chain = save_cleanups ();
+void
+exception_print (struct ui_file *file, struct gdb_exception e)
+{
+ if (e.reason < 0 && e.message != NULL)
+ {
+ print_flush ();
+ print_exception (file, e);
+ }
+}
- /* Call FUNC, catching error/quit events. */
+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 ();
- saved_catch = catch_return;
- catch_return = &catch;
- caught = SIGSETJMP (catch);
- if (!caught)
- val = (*func) (func_uiout, func_args);
- else
+ /* 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)
{
- val = 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)
- *gdberrmsg = error_last_message ();
+ 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);
}
- catch_return = saved_catch;
+}
- /* FIXME: cagney/1999-11-05: A correct FUNC implementation will
- clean things up (restoring the cleanup chain) to the state they
- were just prior to the call. Unfortunately, many FUNC's are not
- that well behaved. This could be fixed by adding either a
- do_cleanups call (to cover the problem) or an assertion check to
- detect bad FUNCs code. */
+/* 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.
- /* Restore the cleanup chain, the error/quit messages, and the uiout
- builder, to their original states. */
+ 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;
- restore_cleanups (saved_cleanup_chain);
+/* The number of currently allocated entries in exception_messages. */
+static int exception_messages_size;
- uiout = saved_uiout;
+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;
+ int depth = catcher_list_size ();
- if (mask & RETURN_MASK_QUIT)
- quit_pre_print = saved_quit_pre_print;
- if (mask & RETURN_MASK_ERROR)
- error_pre_print = saved_error_pre_print;
+ gdb_assert (depth > 0);
- /* Return normally if no error/quit event occurred or this catcher
- can handle this exception. The caller analyses the func return
- values. */
+ /* Note: The new message may use an old message's text. */
+ new_message = xstrvprintf (fmt, ap);
- if (!caught || (mask & RETURN_MASK (caught)))
+ if (depth > exception_messages_size)
{
- *func_val = val;
- *func_caught = caught;
- return;
+ 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 *));
}
- /* The caller didn't request that the event be caught, relay the
- event to the next containing catch_errors(). */
+ xfree (exception_messages[depth - 1]);
+ exception_messages[depth - 1] = new_message;
+
+ /* Create the exception. */
+ e.reason = reason;
+ e.error = error;
+ e.message = new_message;
- throw_exception (caught);
+ /* 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
+ 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
+ initialized the longjmp buffers. */
+
int
catch_exceptions (struct ui_out *uiout,
catch_exceptions_ftype *func,
void *func_args,
- char *errstring,
return_mask mask)
{
- int val;
- enum return_reason caught;
- catcher (func, uiout, func_args, &val, &caught, errstring, NULL, mask);
- gdb_assert (val >= 0);
- gdb_assert (caught <= 0);
- if (caught < 0)
- return caught;
- return val;
+ 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;
- enum return_reason caught;
- catcher (func, uiout, func_args, &val, &caught, errstring, gdberrmsg, mask);
+ volatile struct gdb_exception exception;
+ 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_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)
+ {
+ /* 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 (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;
}
-struct catch_errors_args
-{
- catch_errors_ftype *func;
- void *func_args;
-};
-
-static int
-do_catch_errors (struct ui_out *uiout, void *data)
-{
- struct catch_errors_args *args = data;
- return args->func (args->func_args);
-}
+/* This function is superseded by catch_exceptions(). */
int
catch_errors (catch_errors_ftype *func, void *func_args, char *errstring,
return_mask mask)
{
- int val;
- enum return_reason caught;
- struct catch_errors_args args;
- args.func = func;
- args.func_args = func_args;
- catcher (do_catch_errors, uiout, &args, &val, &caught, errstring,
- NULL, mask);
- if (caught != 0)
+ volatile int val = 0;
+ 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;
return val;
}
-struct captured_command_args
- {
- catch_command_errors_ftype *command;
- char *arg;
- int from_tty;
- };
-
-static int
-do_captured_command (void *data)
+int
+catch_command_errors (catch_command_errors_ftype *command,
+ char *arg, int from_tty, return_mask mask)
{
- 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);
+ 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 (catch_command_errors_ftype * command,
- char *arg, int from_tty, return_mask mask)
+catch_command_errors_const (catch_command_errors_const_ftype *command,
+ const char *arg, int from_tty, return_mask mask)
{
- struct captured_command_args args;
- args.command = command;
- args.arg = arg;
- args.from_tty = from_tty;
- return catch_errors (do_captured_command, &args, "", 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;
}
projects / deliverable / binutils-gdb.git / blobdiff