OpenModem/bertos/mware/except.h

125 lines
3.7 KiB
C

/**
* \file
* <!--
* This file is part of BeRTOS.
*
* Bertos 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 2 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, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* As a special exception, you may use this file as part of a free software
* library without restriction. Specifically, if other files instantiate
* templates or use macros or inline functions from this file, or you compile
* this file and link it with other files to produce an executable, this
* file does not by itself cause the resulting executable to be covered by
* the GNU General Public License. This exception does not however
* invalidate any other reasons why the executable file might be covered by
* the GNU General Public License.
*
* Copyright 2006 Develer S.r.l. (http://www.develer.com/)
* Copyright 1999 Bernie Innocenti <bernie@codewiz.org>
*
* -->
*
* \brief C++-like structured exception handling for C programs
*
* \author Bernie Innocenti <bernie@codewiz.org>
*/
#ifndef MWARE_EXCEPT_H
#define MWARE_EXCEPT_H
#include <cfg/debug.h>
#include <setjmp.h>
#define EXCEPT_CONTEXTS 8
/**
* A stack of jump buffers used to record try sites
* so they can be reached from throw sites.
*
* The stack contains return points for each nested
* context. jmp_buf's are pushed into the stack at
* try points and popped out when the try block ends
* normally or when an exception is thrown.
*/
extern jmp_buf except_stack[EXCEPT_CONTEXTS];
extern int except_top;
#define PUSH_EXCEPT (ASSERT(except_top < EXCEPT_CONTEXTS), setjmp(except_stack[except_top++]))
#define POP_EXCEPT (ASSERT(except_top > 0), --except_top)
#define DO_EXCEPT (ASSERT(except_top > 0), longjmp(except_stack[--except_top], true))
/**
* Jump buffer to use when throwing an exception or aborting an operation
*
* User code can throw exceptions like this:
*
* \code
* void a_function_throwing_exceptions(void)
* {
* if (some_error_condition)
* THROW;
* }
* \endcode
*
* Catching exceptions (brackets are optional):
*
* \code
* EXCEPT_DEFINE;
*
* void a_function_catching_an_exception(void)
* {
* TRY
* {
* printf("Entered try block\n");
* a_function_throwing_exceptions();
* printf("Survived execution of critical code\n");
* }
* CATCH
* {
* printf("Exception caught!\n");
* }
* CATCH_END
* }
* \endcode
*
* Simple syntax when you don't need to do anything when catching an excaption:
*
* \code
* TRY
* printf("Entered try block\n");
* a_function_throwing_exceptions();
* printf("Survived execution of critical code\n");
* TRY_END
* \endcode
*
* You also need to declare the exception stack once in
* your global declarations:
* \code
* EXCEPT_DEFINE;
* \endcode
*/
#define TRY if (PUSH_EXCEPT) { {
#define TRY_END } POP_EXCEPT; }
#define CATCH } POP_EXCEPT; } else {
#define CATCH_END }
#define THROW DO_EXCEPT
#define EXCEPT_DEFINE \
jmp_buf except_stack[EXCEPT_CONTEXTS]; \
int except_top;
#endif /* MWARE_EXCEPT_H */