gdb/exceptions.c

   1 /* Exception (throw catch) mechanism, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2025 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 "exceptions.h"
  21 #include "target.h"
  22 #include "inferior.h"
  23 #include "annotate.h"
  24 #include "ui-out.h"
  25 #include "serial.h"
  26 #include "ui.h"
  27 #include <optional>
  28 #include "cli/cli-style.h"
  29
  30 static void
  31 print_flush (void)
  32 {
  33   struct ui *ui = current_ui;
  34   struct serial *gdb_stdout_serial;
  35
  36   if (deprecated_error_begin_hook)
  37     deprecated_error_begin_hook ();
  38
  39   std::optional<target_terminal::scoped_restore_terminal_state> term_state;
  40   if (target_supports_terminal_ours ())
  41     {
  42       term_state.emplace ();
  43       target_terminal::ours_for_output ();
  44     }
  45
  46   /* We want all output to appear now, before we print the error.  We
  47      have 2 levels of buffering we have to flush (it's possible that
  48      some of these should be changed to flush the lower-level ones
  49      too):  */
  50
  51   /* 1.  The stdio buffer.  */
  52   gdb_flush (gdb_stdout);
  53   gdb_flush (gdb_stderr);
  54
  55   /* 2.  The system-level buffer.  */
  56   gdb_stdout_serial = serial_fdopen (fileno (ui->outstream));
  57   if (gdb_stdout_serial)
  58     {
  59       serial_drain_output (gdb_stdout_serial);
  60       serial_un_fdopen (gdb_stdout_serial);
  61     }
  62
  63   annotate_error_begin ();
  64 }
  65
  66 static void
  67 print_exception (struct ui_file *file, const struct gdb_exception &e)
  68 {
  69   /* KLUDGE: cagney/2005-01-13: Write the string out one line at a time
  70      as that way the MI's behavior is preserved.  */
  71   const char *start;
  72   const char *end;
  73
  74   for (start = e.what (); start != NULL; start = end)
  75     {
  76       end = strchr (start, '\n');
  77       if (end == NULL)
  78         gdb_puts (start, file);
  79       else
  80         {
  81           end++;
  82           file->write (start, end - start);
  83         }
  84     }
  85   gdb_printf (file, "\n");
  86
  87   /* Now append the annotation.  */
  88   switch (e.reason)
  89     {
  90     case RETURN_QUIT:
  91     case RETURN_FORCED_QUIT:
  92       annotate_quit ();
  93       break;
  94     case RETURN_ERROR:
  95       /* Assume that these are all errors.  */
  96       annotate_error ();
  97       break;
  98     default:
  99       internal_error (_("Bad switch."));
 100     }
 101 }
 102
 103 void
 104 exception_print (struct ui_file *file, const struct gdb_exception &e)
 105 {
 106   if (e.reason < 0 && e.message != NULL)
 107     {
 108       print_flush ();
 109       print_error_prefix (file);
 110       print_exception (file, e);
 111     }
 112 }
 113
 114 void
 115 exception_fprintf (struct ui_file *file, const struct gdb_exception &e,
 116                    const char *prefix, ...)
 117 {
 118   if (e.reason < 0 && e.message != NULL)
 119     {
 120       va_list args;
 121
 122       print_flush ();
 123       print_error_prefix (file);
 124
 125       /* Print the prefix.  */
 126       va_start (args, prefix);
 127       gdb_vprintf (file, prefix, args);
 128       va_end (args);
 129
 130       print_exception (file, e);
 131     }
 132 }