gdb/exceptions.c

/* Exception (throw catch) mechanism, for GDB, the GNU debugger.

   Copyright (C) 1986-2025 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 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   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, see <http://www.gnu.org/licenses/>.  */

#include "exceptions.h"
#include "target.h"
#include "inferior.h"
#include "annotate.h"
#include "ui-out.h"
#include "serial.h"
#include "ui.h"
#include <optional>
#include "cli/cli-style.h"

static void
print_flush (void)
{
  struct ui *ui = current_ui;
  struct serial *gdb_stdout_serial;

  if (deprecated_error_begin_hook)
    deprecated_error_begin_hook ();

  std::optional<target_terminal::scoped_restore_terminal_state> term_state;
  if (target_supports_terminal_ours ())
    {
      term_state.emplace ();
      target_terminal::ours_for_output ();
    }

  /* We want all output to appear now, before we print the error.  We
     have 2 levels of buffering we have to flush (it's possible that
     some of these should be changed to flush the lower-level ones
     too):  */

  /* 1.  The stdio buffer.  */
  gdb_flush (gdb_stdout);
  gdb_flush (gdb_stderr);

  /* 2.  The system-level buffer.  */
  gdb_stdout_serial = serial_fdopen (fileno (ui->outstream));
  if (gdb_stdout_serial)
    {
      serial_drain_output (gdb_stdout_serial);
      serial_un_fdopen (gdb_stdout_serial);
    }

  annotate_error_begin ();
}

static void
print_exception (struct ui_file *file, const struct gdb_exception &e)
{
  /* KLUDGE: 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;

  for (start = e.what (); start != NULL; start = end)
    {
      end = strchr (start, '\n');
      if (end == NULL)
	gdb_puts (start, file);
      else
	{
	  end++;
	  file->write (start, end - start);
	}
    }
  gdb_printf (file, "\n");

  /* Now append the annotation.  */
  switch (e.reason)
    {
    case RETURN_QUIT:
    case RETURN_FORCED_QUIT:
      annotate_quit ();
      break;
    case RETURN_ERROR:
      /* Assume that these are all errors.  */
      annotate_error ();
      break;
    default:
      internal_error (_("Bad switch."));
    }
}

void
exception_print (struct ui_file *file, const struct gdb_exception &e)
{
  if (e.reason < 0 && e.message != NULL)
    {
      print_flush ();
      print_error_prefix (file);
      print_exception (file, e);
    }
}

void
exception_fprintf (struct ui_file *file, const struct gdb_exception &e,
		   const char *prefix, ...)
{
  if (e.reason < 0 && e.message != NULL)
    {
      va_list args;

      print_flush ();
      print_error_prefix (file);

      /* Print the prefix.  */
      va_start (args, prefix);
      gdb_vprintf (file, prefix, args);
      va_end (args);

      print_exception (file, e);
    }
}