lumiera_/src/lib/error.h
Ichthyostega ada5cefaaf re-arrange tests according to layer structure
the buildsystem will now pick up and link
all test cases according to the layer, e.g.
backend tests will automatically be linked
against the backend + library solely.
2013-01-07 05:43:01 +01:00

202 lines
8.7 KiB
C

/*
ERROR.h - Lumiera Error handling interface (C-style)
Copyright (C) Lumiera.org
2008, Christian Thaeter <ct@pipapo.org>
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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file error.h
** Lumiera error handling (C interface).
** This header declares the interface for C-style error handling
** based on a thread local error flag. This error state is "sticky";
** client code is bound to clear the error flag explicitly before
** being able to set another error state.
**
** Error states are tightly integrated with NoBug based logging, as well
** as with the exceptions used by the C++ part of the application: throwing
** an exception automatically sets the error flag, and by policy, any
** catch clause has to check, log and clear the error flag too.
**
** @see error.hpp C++ interface
** @see error-state.c
** @see error-exception.cpp
**
*/
#ifndef LUMIERA_ERROR_H
#define LUMIERA_ERROR_H
#ifdef __cplusplus
extern "C" {
#elif 0
} /* fixes broken emacs indenting */
#endif
#include <nobug.h>
#include <stdlib.h>
typedef const char* lumiera_err;
/**
* Abort unconditionally with a 'Fatal Error!' message.
* This macro is used whenever the program end up in a invalid state from which no runtime recovery is possible
*/
#define LUMIERA_DIE(err) \
do { NOBUG_ERROR(NOBUG_ON, "Fatal Error: %s ", strchr(LUMIERA_ERROR_##err, ':')); abort(); } while(0)
/**
* Forward declare an error constant.
* This macro eases the error declaration in header files
* @param err name of the error without the 'LUMIERA_ERROR_' prefix (example: NO_MEMORY)
*/
#define LUMIERA_ERROR_DECLARE(err) \
extern lumiera_err LUMIERA_ERROR_##err
/**
* Definition and initialization of an error constant.
* This macro eases the error definition in implementation files
* @param err name of the error without the 'LUMIERA_ERROR_' prefix (example: NO_MEMORY)
* @param msg message describing the error in plain english (example: "memory allocation failed")
*/
#define LUMIERA_ERROR_DEFINE(err, msg) \
lumiera_err LUMIERA_ERROR_##err = "LUMIERA_ERROR_" #err ":" msg
/**
* Helper macro to raise an error for the current thread.
* This macro eases setting an error. It adds NoBug logging support to the low level error handling.
* Used for unexpected errors which can be handled without any problems.
* @param flag NoBug flag describing the subsystem where the error was raised
* @param err name of the error without the 'LUMIERA_ERROR_' prefix (example: NO_MEMORY)
* @param extra optional string (or NULL) which adds some more context to the error, can be a temporary
*/
#define LUMIERA_ERROR_SET(flag, err, extra) \
do { \
const char* theextra = extra; \
ERROR (flag, "%s%s%s", strchr(LUMIERA_ERROR_##err, ':')+1, theextra?": ":"", theextra?theextra:""); \
lumiera_error_set(LUMIERA_ERROR_##err, theextra); \
} while (0)
/**
* Helper macro to raise an error for the current thread.
* Same as LUMIERA_ERROR_SET(), but logs at 'LOG_ALERT' level.
* Use this when the application is about to do a emergency shutdown.
* @param flag NoBug flag describing the subsystem where the error was raised
* @param err name of the error without the 'LUMIERA_ERROR_' prefix (example: NO_MEMORY)
* @param extra optional string (or NULL) which adds some more context to the error, can be a temporary
*/
#define LUMIERA_ERROR_SET_ALERT(flag, err, extra) \
do { \
const char* theextra = extra; \
ALERT (flag, "%s%s%s", strchr(LUMIERA_ERROR_##err, ':')+1, theextra?": ":"", theextra?theextra:""); \
lumiera_error_set(LUMIERA_ERROR_##err, theextra); \
} while (0)
/**
* Helper macro to raise an error for the current thread.
* Same as LUMIERA_ERROR_SET(), but logs at 'LOG_CRIT' level.
* Use this when a requested task can not be completed (maybe user intervention is necessary).
* @param flag NoBug flag describing the subsystem where the error was raised
* @param err name of the error without the 'LUMIERA_ERROR_' prefix (example: NO_MEMORY)
* @param extra optional string (or NULL) which adds some more context to the error, can be a temporary
*/
#define LUMIERA_ERROR_SET_CRITICAL(flag, err, extra) \
do { \
const char* theextra = extra; \
CRITICAL (flag, "%s%s%s", strchr(LUMIERA_ERROR_##err, ':')+1, theextra?": ":"", theextra?theextra:"");\
lumiera_error_set(LUMIERA_ERROR_##err, theextra); \
} while (0)
/**
* Helper macro to raise an error for the current thread.
* Same as LUMIERA_ERROR_SET(), but logs at 'LOG_WARNING' level.
* Use this when a not unexected error happens which can be handled.
* @param flag NoBug flag describing the subsystem where the error was raised
* @param err name of the error without the 'LUMIERA_ERROR_' prefix (example: NO_MEMORY)
* @param extra optional string (or NULL) which adds some more context to the error, can be a temporary
*/
#define LUMIERA_ERROR_SET_WARNING(flag, err, extra) \
do { \
const char* theextra = extra; \
WARN (flag, "%s%s%s", strchr(LUMIERA_ERROR_##err, ':')+1, theextra?": ":"", theextra?theextra:""); \
lumiera_error_set(LUMIERA_ERROR_##err, theextra); \
} while (0)
/**
* Set error state for the current thread.
* If the error state of the current thread was cleared, then set it, else preserve the old state.
* @param nerr name of the error with 'LUMIERA_ERROR_' prefix (example: LUMIERA_ERROR_NO_MEMORY)
* @param extra a string (possibly a constructed tmpbuf) which adds some more context to the error, can be a temporary
* @return old state, that is NULL for success, when the state was cleared and a pointer to a pending
* error when the error state was already set
*/
lumiera_err
lumiera_error_set (lumiera_err nerr, const char* extra);
/**
* Query the extra context for the last error
* @return the extra string from the last error
*/
const char*
lumiera_error_extra (void);
/**
* Get and clear current error state.
* This function clears the error state, if it needs to be reused, one has to store it in a temporary
* variable.
* @return pointer to any pending error of this thread, NULL if no error is pending
*/
lumiera_err
lumiera_error (void);
/**
* Check current error state without clearing it
* Please avoid this function and use lumiera_error() if possible. Errors must be cleared else certain
* parts of the application refuse to cooperate with you. This shall only be used to decide if one
* wants to barf out of a loop or subroutine to deliver the error to a higher level.
* @return pointer to any pending error of this thread, NULL if no error is pending
*/
lumiera_err
lumiera_error_peek (void);
/**
* Expect some error
* Check that the current error state matches some expectation, if true then the error state
* is cleared and 1 is returned, otherwise 0 is returned and the error state remains set.
* @param expected error which is expected
* @return 1 if the current error state equals the expected state, else 0, the error state is cleared when the expectation is met
*/
int
lumiera_error_expect (lumiera_err expected);
/*
predefined errors
*/
LUMIERA_ERROR_DECLARE (ERRNO);
LUMIERA_ERROR_DECLARE (UNKNOWN);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* LUMIERA_ERROR_H */