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:
- a diagnostic message may be logged to the system logger with syslog(3). This is default behaviour.
- a diagnostic message may be printed to the
stderr
stream. - 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 library “libc” 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:
DIAGNOSTICS
The diagnostic message has the following format:
"assertion \"%s\" failed: file \"%s\", line %d, function \"%s\"\n", "expression", __FILE__, __LINE__, __func__
SEE ALSO
HISTORY
The _DIAGASSERT
macro appeared in
NetBSD 1.5.