| 1 | /* Exception (throw catch) mechanism, for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 1986-2017 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 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. |
| 11 | |
| 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. |
| 16 | |
| 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/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "exceptions.h" |
| 22 | #include "breakpoint.h" |
| 23 | #include "target.h" |
| 24 | #include "inferior.h" |
| 25 | #include "annotate.h" |
| 26 | #include "ui-out.h" |
| 27 | #include "serial.h" |
| 28 | #include "gdbthread.h" |
| 29 | #include "top.h" |
| 30 | |
| 31 | static void |
| 32 | print_flush (void) |
| 33 | { |
| 34 | struct ui *ui = current_ui; |
| 35 | struct serial *gdb_stdout_serial; |
| 36 | struct cleanup *old_chain = make_cleanup (null_cleanup, NULL); |
| 37 | |
| 38 | if (deprecated_error_begin_hook) |
| 39 | deprecated_error_begin_hook (); |
| 40 | |
| 41 | if (target_supports_terminal_ours ()) |
| 42 | { |
| 43 | make_cleanup_restore_target_terminal (); |
| 44 | target_terminal_ours_for_output (); |
| 45 | } |
| 46 | |
| 47 | /* We want all output to appear now, before we print the error. We |
| 48 | have 3 levels of buffering we have to flush (it's possible that |
| 49 | some of these should be changed to flush the lower-level ones |
| 50 | too): */ |
| 51 | |
| 52 | /* 1. The _filtered buffer. */ |
| 53 | if (filtered_printing_initialized ()) |
| 54 | wrap_here (""); |
| 55 | |
| 56 | /* 2. The stdio buffer. */ |
| 57 | gdb_flush (gdb_stdout); |
| 58 | gdb_flush (gdb_stderr); |
| 59 | |
| 60 | /* 3. The system-level buffer. */ |
| 61 | gdb_stdout_serial = serial_fdopen (fileno (ui->outstream)); |
| 62 | if (gdb_stdout_serial) |
| 63 | { |
| 64 | serial_drain_output (gdb_stdout_serial); |
| 65 | serial_un_fdopen (gdb_stdout_serial); |
| 66 | } |
| 67 | |
| 68 | annotate_error_begin (); |
| 69 | |
| 70 | do_cleanups (old_chain); |
| 71 | } |
| 72 | |
| 73 | static void |
| 74 | print_exception (struct ui_file *file, struct gdb_exception e) |
| 75 | { |
| 76 | /* KLUGE: cagney/2005-01-13: Write the string out one line at a time |
| 77 | as that way the MI's behavior is preserved. */ |
| 78 | const char *start; |
| 79 | const char *end; |
| 80 | |
| 81 | for (start = e.message; start != NULL; start = end) |
| 82 | { |
| 83 | end = strchr (start, '\n'); |
| 84 | if (end == NULL) |
| 85 | fputs_filtered (start, file); |
| 86 | else |
| 87 | { |
| 88 | end++; |
| 89 | ui_file_write (file, start, end - start); |
| 90 | } |
| 91 | } |
| 92 | fprintf_filtered (file, "\n"); |
| 93 | |
| 94 | /* Now append the annotation. */ |
| 95 | switch (e.reason) |
| 96 | { |
| 97 | case RETURN_QUIT: |
| 98 | annotate_quit (); |
| 99 | break; |
| 100 | case RETURN_ERROR: |
| 101 | /* Assume that these are all errors. */ |
| 102 | annotate_error (); |
| 103 | break; |
| 104 | default: |
| 105 | internal_error (__FILE__, __LINE__, _("Bad switch.")); |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | void |
| 110 | exception_print (struct ui_file *file, struct gdb_exception e) |
| 111 | { |
| 112 | if (e.reason < 0 && e.message != NULL) |
| 113 | { |
| 114 | print_flush (); |
| 115 | print_exception (file, e); |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | void |
| 120 | exception_fprintf (struct ui_file *file, struct gdb_exception e, |
| 121 | const char *prefix, ...) |
| 122 | { |
| 123 | if (e.reason < 0 && e.message != NULL) |
| 124 | { |
| 125 | va_list args; |
| 126 | |
| 127 | print_flush (); |
| 128 | |
| 129 | /* Print the prefix. */ |
| 130 | va_start (args, prefix); |
| 131 | vfprintf_filtered (file, prefix, args); |
| 132 | va_end (args); |
| 133 | |
| 134 | print_exception (file, e); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | /* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception |
| 139 | handler. If an exception (enum return_reason) is thrown using |
| 140 | throw_exception() than all cleanups installed since |
| 141 | catch_exceptions() was entered are invoked, the (-ve) exception |
| 142 | value is then returned by catch_exceptions. If FUNC() returns |
| 143 | normally (with a positive or zero return value) then that value is |
| 144 | returned by catch_exceptions(). It is an internal_error() for |
| 145 | FUNC() to return a negative value. |
| 146 | |
| 147 | See exceptions.h for further usage details. */ |
| 148 | |
| 149 | /* MAYBE: cagney/1999-11-05: catch_errors() in conjunction with |
| 150 | error() et al. could maintain a set of flags that indicate the |
| 151 | current state of each of the longjmp buffers. This would give the |
| 152 | longjmp code the chance to detect a longjmp botch (before it gets |
| 153 | to longjmperror()). Prior to 1999-11-05 this wasn't possible as |
| 154 | code also randomly used a SET_TOP_LEVEL macro that directly |
| 155 | initialized the longjmp buffers. */ |
| 156 | |
| 157 | int |
| 158 | catch_exceptions (struct ui_out *uiout, |
| 159 | catch_exceptions_ftype *func, |
| 160 | void *func_args, |
| 161 | return_mask mask) |
| 162 | { |
| 163 | return catch_exceptions_with_msg (uiout, func, func_args, NULL, mask); |
| 164 | } |
| 165 | |
| 166 | int |
| 167 | catch_exceptions_with_msg (struct ui_out *func_uiout, |
| 168 | catch_exceptions_ftype *func, |
| 169 | void *func_args, |
| 170 | char **gdberrmsg, |
| 171 | return_mask mask) |
| 172 | { |
| 173 | struct gdb_exception exception = exception_none; |
| 174 | volatile int val = 0; |
| 175 | struct ui_out *saved_uiout; |
| 176 | |
| 177 | /* Save and override the global ``struct ui_out'' builder. */ |
| 178 | saved_uiout = current_uiout; |
| 179 | current_uiout = func_uiout; |
| 180 | |
| 181 | TRY |
| 182 | { |
| 183 | val = (*func) (current_uiout, func_args); |
| 184 | } |
| 185 | CATCH (ex, RETURN_MASK_ALL) |
| 186 | { |
| 187 | exception = ex; |
| 188 | } |
| 189 | END_CATCH |
| 190 | |
| 191 | /* Restore the global builder. */ |
| 192 | current_uiout = saved_uiout; |
| 193 | |
| 194 | if (exception.reason < 0 && (mask & RETURN_MASK (exception.reason)) == 0) |
| 195 | { |
| 196 | /* The caller didn't request that the event be caught. |
| 197 | Rethrow. */ |
| 198 | throw_exception (exception); |
| 199 | } |
| 200 | |
| 201 | exception_print (gdb_stderr, exception); |
| 202 | gdb_assert (val >= 0); |
| 203 | gdb_assert (exception.reason <= 0); |
| 204 | if (exception.reason < 0) |
| 205 | { |
| 206 | /* If caller wants a copy of the low-level error message, make |
| 207 | one. This is used in the case of a silent error whereby the |
| 208 | caller may optionally want to issue the message. */ |
| 209 | if (gdberrmsg != NULL) |
| 210 | { |
| 211 | if (exception.message != NULL) |
| 212 | *gdberrmsg = xstrdup (exception.message); |
| 213 | else |
| 214 | *gdberrmsg = NULL; |
| 215 | } |
| 216 | return exception.reason; |
| 217 | } |
| 218 | return val; |
| 219 | } |
| 220 | |
| 221 | /* This function is superseded by catch_exceptions(). */ |
| 222 | |
| 223 | int |
| 224 | catch_errors (catch_errors_ftype *func, void *func_args, |
| 225 | const char *errstring, return_mask mask) |
| 226 | { |
| 227 | struct gdb_exception exception = exception_none; |
| 228 | volatile int val = 0; |
| 229 | struct ui_out *saved_uiout; |
| 230 | |
| 231 | /* Save the global ``struct ui_out'' builder. */ |
| 232 | saved_uiout = current_uiout; |
| 233 | |
| 234 | TRY |
| 235 | { |
| 236 | val = func (func_args); |
| 237 | } |
| 238 | CATCH (ex, RETURN_MASK_ALL) |
| 239 | { |
| 240 | exception = ex; |
| 241 | } |
| 242 | END_CATCH |
| 243 | |
| 244 | /* Restore the global builder. */ |
| 245 | current_uiout = saved_uiout; |
| 246 | |
| 247 | if (exception.reason < 0 && (mask & RETURN_MASK (exception.reason)) == 0) |
| 248 | { |
| 249 | /* The caller didn't request that the event be caught. |
| 250 | Rethrow. */ |
| 251 | throw_exception (exception); |
| 252 | } |
| 253 | |
| 254 | exception_fprintf (gdb_stderr, exception, "%s", errstring); |
| 255 | if (exception.reason != 0) |
| 256 | return 0; |
| 257 | return val; |
| 258 | } |
| 259 | |
| 260 | /* See exceptions.h. */ |
| 261 | |
| 262 | int |
| 263 | exception_print_same (struct gdb_exception e1, struct gdb_exception e2) |
| 264 | { |
| 265 | const char *msg1 = e1.message; |
| 266 | const char *msg2 = e2.message; |
| 267 | |
| 268 | if (msg1 == NULL) |
| 269 | msg1 = ""; |
| 270 | if (msg2 == NULL) |
| 271 | msg2 = ""; |
| 272 | |
| 273 | return (e1.reason == e2.reason |
| 274 | && e1.error == e2.error |
| 275 | && strcmp (msg1, msg2) == 0); |
| 276 | } |