1 /* Exception (throw catch) mechanism, for GDB, the GNU debugger.
3 Copyright (C) 1986-2016 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "exceptions.h"
22 #include "breakpoint.h"
28 #include "gdbthread.h"
31 prepare_to_throw_exception (void)
38 struct serial *gdb_stdout_serial;
39 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
41 if (deprecated_error_begin_hook)
42 deprecated_error_begin_hook ();
44 if (target_supports_terminal_ours ())
46 make_cleanup_restore_target_terminal ();
47 target_terminal_ours_for_output ();
50 /* We want all output to appear now, before we print the error. We
51 have 3 levels of buffering we have to flush (it's possible that
52 some of these should be changed to flush the lower-level ones
55 /* 1. The _filtered buffer. */
56 if (filtered_printing_initialized ())
59 /* 2. The stdio buffer. */
60 gdb_flush (gdb_stdout);
61 gdb_flush (gdb_stderr);
63 /* 3. The system-level buffer. */
64 gdb_stdout_serial = serial_fdopen (1);
65 if (gdb_stdout_serial)
67 serial_drain_output (gdb_stdout_serial);
68 serial_un_fdopen (gdb_stdout_serial);
71 annotate_error_begin ();
73 do_cleanups (old_chain);
77 print_exception (struct ui_file *file, struct gdb_exception e)
79 /* KLUGE: cagney/2005-01-13: Write the string out one line at a time
80 as that way the MI's behavior is preserved. */
84 for (start = e.message; start != NULL; start = end)
86 end = strchr (start, '\n');
88 fputs_filtered (start, file);
92 ui_file_write (file, start, end - start);
95 fprintf_filtered (file, "\n");
97 /* Now append the annotation. */
104 /* Assume that these are all errors. */
108 internal_error (__FILE__, __LINE__, _("Bad switch."));
113 exception_print (struct ui_file *file, struct gdb_exception e)
115 if (e.reason < 0 && e.message != NULL)
118 print_exception (file, e);
123 exception_fprintf (struct ui_file *file, struct gdb_exception e,
124 const char *prefix, ...)
126 if (e.reason < 0 && e.message != NULL)
132 /* Print the prefix. */
133 va_start (args, prefix);
134 vfprintf_filtered (file, prefix, args);
137 print_exception (file, e);
141 /* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
142 handler. If an exception (enum return_reason) is thrown using
143 throw_exception() than all cleanups installed since
144 catch_exceptions() was entered are invoked, the (-ve) exception
145 value is then returned by catch_exceptions. If FUNC() returns
146 normally (with a positive or zero return value) then that value is
147 returned by catch_exceptions(). It is an internal_error() for
148 FUNC() to return a negative value.
150 See exceptions.h for further usage details. */
152 /* MAYBE: cagney/1999-11-05: catch_errors() in conjunction with
153 error() et al. could maintain a set of flags that indicate the
154 current state of each of the longjmp buffers. This would give the
155 longjmp code the chance to detect a longjmp botch (before it gets
156 to longjmperror()). Prior to 1999-11-05 this wasn't possible as
157 code also randomly used a SET_TOP_LEVEL macro that directly
158 initialized the longjmp buffers. */
161 catch_exceptions (struct ui_out *uiout,
162 catch_exceptions_ftype *func,
166 return catch_exceptions_with_msg (uiout, func, func_args, NULL, mask);
170 catch_exceptions_with_msg (struct ui_out *func_uiout,
171 catch_exceptions_ftype *func,
176 struct gdb_exception exception = exception_none;
177 volatile int val = 0;
178 struct ui_out *saved_uiout;
180 /* Save and override the global ``struct ui_out'' builder. */
181 saved_uiout = current_uiout;
182 current_uiout = func_uiout;
186 val = (*func) (current_uiout, func_args);
188 CATCH (ex, RETURN_MASK_ALL)
194 /* Restore the global builder. */
195 current_uiout = saved_uiout;
197 if (exception.reason < 0 && (mask & RETURN_MASK (exception.reason)) == 0)
199 /* The caller didn't request that the event be caught.
201 throw_exception (exception);
204 exception_print (gdb_stderr, exception);
205 gdb_assert (val >= 0);
206 gdb_assert (exception.reason <= 0);
207 if (exception.reason < 0)
209 /* If caller wants a copy of the low-level error message, make
210 one. This is used in the case of a silent error whereby the
211 caller may optionally want to issue the message. */
212 if (gdberrmsg != NULL)
214 if (exception.message != NULL)
215 *gdberrmsg = xstrdup (exception.message);
219 return exception.reason;
224 /* This function is superseded by catch_exceptions(). */
227 catch_errors (catch_errors_ftype *func, void *func_args, char *errstring,
230 struct gdb_exception exception = exception_none;
231 volatile int val = 0;
232 struct ui_out *saved_uiout;
234 /* Save the global ``struct ui_out'' builder. */
235 saved_uiout = current_uiout;
239 val = func (func_args);
241 CATCH (ex, RETURN_MASK_ALL)
247 /* Restore the global builder. */
248 current_uiout = saved_uiout;
250 if (exception.reason < 0 && (mask & RETURN_MASK (exception.reason)) == 0)
252 /* The caller didn't request that the event be caught.
254 throw_exception (exception);
257 exception_fprintf (gdb_stderr, exception, "%s", errstring);
258 if (exception.reason != 0)