ctassert(9) [netbsd man page]

CTASSERT(9)						   BSD Kernel Developer's Manual					       CTASSERT(9)

NAME

     CTASSERT -- compile time assertion macro

SYNOPSIS

     void
     CTASSERT(expression);

DESCRIPTION

     The CTASSERT() macro evaluates expression at compile time and causes a compiler error if it is false.

     The CTASSERT() macro is useful for asserting the size or alignment of important data structures and variables during compilation, which would
     otherwise cause the code to fail at run time.

IMPLEMENTATION NOTES

     The CTASSERT() macro should not be used in a header file.	It is implemented using a dummy typedef, with a name (based on line number) that
     may conflict with a CTASSERT() in a source file including that header.

EXAMPLES

     Assert that the size of the uuid structure is 16 bytes.

	   CTASSERT(sizeof(struct uuid) == 16);

SEE ALSO

     KASSERT(9)

AUTHORS

     This manual page was written by Hiten M. Pandya <hmp@FreeBSD.org>.

BSD
								 January 24, 2010							       BSD

_DIAGASSERT(3)						   BSD Library Functions Manual 					    _DIAGASSERT(3)

NAME

     _DIAGASSERT -- expression verification macro

SYNOPSIS

     #include <assert.h>

     _DIAGASSERT(expression);

DESCRIPTION

     The _DIAGASSERT() macro tests the given expression and if it is false, one or more of the following may occur:

	   o   a diagnostic message may be logged to the system logger with syslog(3).	This is default behaviour.

	   o   a diagnostic message may be printed to the stderr stream.

	   o   the calling process will be terminated by calling abort(3).

     This behaviour may be changed by setting the LIBC_DIAGASSERT environment variable (see below).

     The diagnostic message consists of the text of the expression, the name of the source file, the line number and the enclosing function.

     If expression is true, the _DIAGASSERT() macro does nothing.

     The _DIAGASSERT() macro is not compiled in by default, and will only be compiled in with the cc(1) option -D_DIAGNOSTIC.

     This macro is used in the various system libraries such as the Standard C Library (libc, -lc) to ensure that various library calls are
     invoked with valid arguments.

ENVIRONMENT

     The LIBC_DIAGASSERT environment variable can be used to modify the default behaviour of logging the assertion to the system logger.

     LIBC_DIAGASSERT may be set to one or more of the following characters:

	   a	abort(3) once any assertion messages have been logged and/or printed.

	   A	Opposite of ``a''.

	   e	Print the assertion message to the stderr stream.

	   E	Opposite of ``e''.

	   l	Log the assertion message with syslog(3) to the facility user.debug.

	   L	Opposite of ``l''.

DIAGNOSTICS

     The diagnostic message has the following format:

	   "assertion "%s" failed: file "%s", line %d, function "%s"
",
		       "expression", __FILE__, __LINE__, __func__

SEE ALSO

     cc(1), abort(3), assert(3), syslog(3)

HISTORY

     The _DIAGASSERT macro appeared in NetBSD 1.5.

BSD
								 January 22, 2007							       BSD