gdb/exceptions.c

   1 /* Exception (throw catch) mechanism, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2020 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 #include "gdbsupport/gdb_optional.h"
  31
  32 static void
  33 print_flush (void)
  34 {
  35   struct ui *ui = current_ui;
  36   struct serial *gdb_stdout_serial;
  37
  38   if (deprecated_error_begin_hook)
  39     deprecated_error_begin_hook ();
  40
  41   gdb::optional<target_terminal::scoped_restore_terminal_state> term_state;
  42   if (target_supports_terminal_ours ())
  43     {
  44       term_state.emplace ();
  45       target_terminal::ours_for_output ();
  46     }
  47
  48   /* We want all output to appear now, before we print the error.  We
  49      have 3 levels of buffering we have to flush (it's possible that
  50      some of these should be changed to flush the lower-level ones
  51      too):  */
  52
  53   /* 1.  The _filtered buffer.  */
  54   if (filtered_printing_initialized ())
  55     wrap_here ("");
  56
  57   /* 2.  The stdio buffer.  */
  58   gdb_flush (gdb_stdout);
  59   gdb_flush (gdb_stderr);
  60
  61   /* 3.  The system-level buffer.  */
  62   gdb_stdout_serial = serial_fdopen (fileno (ui->outstream));
  63   if (gdb_stdout_serial)
  64     {
  65       serial_drain_output (gdb_stdout_serial);
  66       serial_un_fdopen (gdb_stdout_serial);
  67     }
  68
  69   annotate_error_begin ();
  70 }
  71
  72 static void
  73 print_exception (struct ui_file *file, const struct gdb_exception &e)
  74 {
  75   /* KLUDGE: cagney/2005-01-13: Write the string out one line at a time
  76      as that way the MI's behavior is preserved.  */
  77   const char *start;
  78   const char *end;
  79
  80   for (start = e.what (); start != NULL; start = end)
  81     {
  82       end = strchr (start, '\n');
  83       if (end == NULL)
  84         fputs_filtered (start, file);
  85       else
  86         {
  87           end++;
  88           ui_file_write (file, start, end - start);
  89         }
  90     }
  91   fprintf_filtered (file, "\n");
  92
  93   /* Now append the annotation.  */
  94   switch (e.reason)
  95     {
  96     case RETURN_QUIT:
  97       annotate_quit ();
  98       break;
  99     case RETURN_ERROR:
 100       /* Assume that these are all errors.  */
 101       annotate_error ();
 102       break;
 103     default:
 104       internal_error (__FILE__, __LINE__, _("Bad switch."));
 105     }
 106 }
 107
 108 void
 109 exception_print (struct ui_file *file, const struct gdb_exception &e)
 110 {
 111   if (e.reason < 0 && e.message != NULL)
 112     {
 113       print_flush ();
 114       print_exception (file, e);
 115     }
 116 }
 117
 118 void
 119 exception_fprintf (struct ui_file *file, const struct gdb_exception &e,
 120                    const char *prefix, ...)
 121 {
 122   if (e.reason < 0 && e.message != NULL)
 123     {
 124       va_list args;
 125
 126       print_flush ();
 127
 128       /* Print the prefix.  */
 129       va_start (args, prefix);
 130       vfprintf_filtered (file, prefix, args);
 131       va_end (args);
 132
 133       print_exception (file, e);
 134     }
 135 }
 136
 137 /* See exceptions.h.  */
 138
 139 int
 140 exception_print_same (const struct gdb_exception &e1,
 141                       const struct gdb_exception &e2)
 142 {
 143   const char *msg1 = e1.message == nullptr ? "" : e1.what ();
 144   const char *msg2 = e2.message == nullptr ? "" : e2.what ();
 145
 146   return (e1.reason == e2.reason
 147           && e1.error == e2.error
 148           && strcmp (msg1, msg2) == 0);
 149 }