haproxy/include/common/debug.h
Willy Tarreau 469fa2c9d9 MINOR: debug: add a new BUG_ON macro
We do have some code paths testing for impossible errors that tend to
be quite confusing, first for maintenance (what to do on such errors,
and how far to guess the bug), second for developers as it tends to
hide the main purpose and expectations of these call places. Also
most of the time impossible errors are ignored by the callers so the
tests are not even usable during debugging.

Let's instead implement a BUG_ON macro which takes a condition, which
if true, will cause a message to be emitted and optionally to crash the
process. Additionally, these calls inserted at various places server as
hints and documentation for developers to know that such conditions
must absolutely not happen.

This is only enabled when DEBUG_STRICT or DEBUG_STRICT_NOCRASH are set.
As its name implies, DEBUG_STRICT_NOCRASH only performs the test but
does not crash, which can be useful to track some checkpoints.

At the moment nothing uses this code.
2019-05-14 17:34:49 +02:00

97 lines
3.1 KiB
C

/*
include/common/debug.h
This files contains some macros to help debugging.
Copyright (C) 2000-2006 Willy Tarreau - w@1wt.eu
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation, version 2.1
exclusively.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _COMMON_DEBUG_H
#define _COMMON_DEBUG_H
#include <common/config.h>
#include <common/memory.h>
#ifdef DEBUG_FULL
#define DPRINTF(x...) fprintf(x)
#else
#define DPRINTF(x...)
#endif
#ifdef DEBUG_FSM
#define FSM_PRINTF(x...) fprintf(x)
#else
#define FSM_PRINTF(x...)
#endif
/* This abort is more efficient than abort() because it does not mangle the
* stack and stops at the exact location we need.
*/
#define ABORT_NOW() (*(volatile int*)1=0)
/* BUG_ON: complains if <cond> is true when DEBUG_STRICT or DEBUG_STRICT_NOCRASH
* are set, does nothing otherwise. With DEBUG_STRICT in addition it immediately
* crashes using ABORT_NOW() above.
*/
#if defined(DEBUG_STRICT) || defined(DEBUG_STRICT_NOCRASH)
#if defined(DEBUG_STRICT)
#define CRASH_NOW() ABORT_NOW()
#else
#define CRASH_NOW()
#endif
#define BUG_ON(cond) _BUG_ON(cond, __FILE__, __LINE__)
#define _BUG_ON(cond, file, line) __BUG_ON(cond, file, line)
#define __BUG_ON(cond, file, line) \
do { \
if (unlikely(cond)) { \
const char msg[] = "\nFATAL: bug condition \"" #cond "\" matched at " file ":" #line "\n"; \
(void)write(2, msg, strlen(msg)); \
CRASH_NOW(); \
} \
} while (0)
#else
#undef CRASH_NOW
#define BUG_ON(cond)
#endif
/* this one is provided for easy code tracing.
* Usage: TRACE(strm||0, fmt, args...);
* TRACE(strm, "");
*/
#define TRACE(strm, fmt, args...) do { \
fprintf(stderr, \
"%d.%06d [%s:%d %s] [strm %p(%x)] " fmt "\n", \
(int)now.tv_sec, (int)now.tv_usec, \
__FILE__, __LINE__, __FUNCTION__, \
strm, strm?((struct stream *)strm)->uniq_id:~0U, \
##args); \
} while (0)
/* This one is useful to automatically apply poisonning on an area returned
* by malloc(). Only "p_" is required to make it work, and to define a poison
* byte using -dM.
*/
static inline void *p_malloc(size_t size)
{
void *ret = malloc(size);
if (mem_poison_byte >= 0 && ret)
memset(ret, mem_poison_byte, size);
return ret;
}
#endif /* _COMMON_DEBUG_H */