gdb/exceptions.h

   1 /* Exception (throw catch) mechanism, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2015 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 #ifndef EXCEPTIONS_H
  21 #define EXCEPTIONS_H
  22
  23 #include "ui-out.h"
  24
  25 /* If E is an exception, print it's error message on the specified
  26    stream.  For _fprintf, prefix the message with PREFIX...  */
  27 extern void exception_print (struct ui_file *file, struct gdb_exception e);
  28 extern void exception_fprintf (struct ui_file *file, struct gdb_exception e,
  29                                const char *prefix,
  30                                ...) ATTRIBUTE_PRINTF (3, 4);
  31
  32 /* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
  33    handler.  If an exception (enum return_reason) is thrown using
  34    throw_exception() than all cleanups installed since
  35    catch_exceptions() was entered are invoked, the (-ve) exception
  36    value is then returned by catch_exceptions.  If FUNC() returns
  37    normally (with a positive or zero return value) then that value is
  38    returned by catch_exceptions().  It is an internal_error() for
  39    FUNC() to return a negative value.
  40
  41    For the period of the FUNC() call: UIOUT is installed as the output
  42    builder; ERRSTRING is installed as the error/quit message; and a
  43    new cleanup_chain is established.  The old values are restored
  44    before catch_exceptions() returns.
  45
  46    The variant catch_exceptions_with_msg() is the same as
  47    catch_exceptions() but adds the ability to return an allocated
  48    copy of the gdb error message.  This is used when a silent error is
  49    issued and the caller wants to manually issue the error message.
  50
  51    MASK specifies what to catch; it is normally set to
  52    RETURN_MASK_ALL, if for no other reason than that the code which
  53    calls catch_errors might not be set up to deal with a quit which
  54    isn't caught.  But if the code can deal with it, it generally
  55    should be RETURN_MASK_ERROR, unless for some reason it is more
  56    useful to abort only the portion of the operation inside the
  57    catch_errors.  Note that quit should return to the command line
  58    fairly quickly, even if some further processing is being done.
  59
  60    FIXME; cagney/2001-08-13: The need to override the global UIOUT
  61    builder variable should just go away.
  62
  63    This function supersedes catch_errors().
  64
  65    This function uses SETJMP() and LONGJUMP().  */
  66
  67 struct ui_out;
  68 typedef int (catch_exceptions_ftype) (struct ui_out *ui_out, void *args);
  69 extern int catch_exceptions (struct ui_out *uiout,
  70                              catch_exceptions_ftype *func, void *func_args,
  71                              return_mask mask);
  72 typedef void (catch_exception_ftype) (struct ui_out *ui_out, void *args);
  73 extern int catch_exceptions_with_msg (struct ui_out *uiout,
  74                                       catch_exceptions_ftype *func,
  75                                       void *func_args,
  76                                       char **gdberrmsg,
  77                                       return_mask mask);
  78
  79 /* If CATCH_ERRORS_FTYPE throws an error, catch_errors() returns zero
  80    otherwize the result from CATCH_ERRORS_FTYPE is returned.  It is
  81    probably useful for CATCH_ERRORS_FTYPE to always return a non-zero
  82    value.  It's unfortunate that, catch_errors() does not return an
  83    indication of the exact exception that it caught - quit_flag might
  84    help.
  85
  86    This function is superseded by catch_exceptions().  */
  87
  88 typedef int (catch_errors_ftype) (void *);
  89 extern int catch_errors (catch_errors_ftype *, void *, char *, return_mask);
  90
  91 #endif