gdb/exceptions.h

   1 /* Exception (throw catch) mechanism, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2014 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 "common-exceptions.h"
  24 #include "ui-out.h"
  25
  26 /* A pre-defined non-exception.  */
  27 extern const struct gdb_exception exception_none;
  28
  29 /* If E is an exception, print it's error message on the specified
  30    stream.  For _fprintf, prefix the message with PREFIX...  */
  31 extern void exception_print (struct ui_file *file, struct gdb_exception e);
  32 extern void exception_fprintf (struct ui_file *file, struct gdb_exception e,
  33                                const char *prefix,
  34                                ...) ATTRIBUTE_PRINTF (3, 4);
  35
  36 /* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
  37    handler.  If an exception (enum return_reason) is thrown using
  38    throw_exception() than all cleanups installed since
  39    catch_exceptions() was entered are invoked, the (-ve) exception
  40    value is then returned by catch_exceptions.  If FUNC() returns
  41    normally (with a positive or zero return value) then that value is
  42    returned by catch_exceptions().  It is an internal_error() for
  43    FUNC() to return a negative value.
  44
  45    For the period of the FUNC() call: UIOUT is installed as the output
  46    builder; ERRSTRING is installed as the error/quit message; and a
  47    new cleanup_chain is established.  The old values are restored
  48    before catch_exceptions() returns.
  49
  50    The variant catch_exceptions_with_msg() is the same as
  51    catch_exceptions() but adds the ability to return an allocated
  52    copy of the gdb error message.  This is used when a silent error is
  53    issued and the caller wants to manually issue the error message.
  54
  55    MASK specifies what to catch; it is normally set to
  56    RETURN_MASK_ALL, if for no other reason than that the code which
  57    calls catch_errors might not be set up to deal with a quit which
  58    isn't caught.  But if the code can deal with it, it generally
  59    should be RETURN_MASK_ERROR, unless for some reason it is more
  60    useful to abort only the portion of the operation inside the
  61    catch_errors.  Note that quit should return to the command line
  62    fairly quickly, even if some further processing is being done.
  63
  64    FIXME; cagney/2001-08-13: The need to override the global UIOUT
  65    builder variable should just go away.
  66
  67    This function supersedes catch_errors().
  68
  69    This function uses SETJMP() and LONGJUMP().  */
  70
  71 struct ui_out;
  72 typedef int (catch_exceptions_ftype) (struct ui_out *ui_out, void *args);
  73 extern int catch_exceptions (struct ui_out *uiout,
  74                              catch_exceptions_ftype *func, void *func_args,
  75                              return_mask mask);
  76 typedef void (catch_exception_ftype) (struct ui_out *ui_out, void *args);
  77 extern int catch_exceptions_with_msg (struct ui_out *uiout,
  78                                       catch_exceptions_ftype *func,
  79                                       void *func_args,
  80                                       char **gdberrmsg,
  81                                       return_mask mask);
  82
  83 /* If CATCH_ERRORS_FTYPE throws an error, catch_errors() returns zero
  84    otherwize the result from CATCH_ERRORS_FTYPE is returned.  It is
  85    probably useful for CATCH_ERRORS_FTYPE to always return a non-zero
  86    value.  It's unfortunate that, catch_errors() does not return an
  87    indication of the exact exception that it caught - quit_flag might
  88    help.
  89
  90    This function is superseded by catch_exceptions().  */
  91
  92 typedef int (catch_errors_ftype) (void *);
  93 extern int catch_errors (catch_errors_ftype *, void *, char *, return_mask);
  94
  95 #endif