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Revision 1.3, Sun May 25 20:06:53 2008 UTC (15 years, 10 months ago) by wiz
Branch: MAIN
CVS Tags: yamt-pf42-base3
Changes since 1.2: +4 -4 lines

Prepare for HTML output. Remove dot at end of SEE ALSO.

.\"	$NetBSD: __builtin_object_size.3,v 1.3 2008/05/25 20:06:53 wiz Exp $
.\"
.\" Copyright (c) 2007 The NetBSD Foundation, Inc.
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Christos Zoulas.
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.Dd May 23, 2007
.Dt __BUILTIN_OBJEXT_SIZE 3
.Os
.Sh NAME
.Nm __builtin_object_size
.Nd return the size of the given object
.Sh LIBRARY
.Ft size_t
.Fn __builtin_object_size "void *ptr" "int type"
.Sh DESCRIPTION
The
.Fn __builtin_object_size
function is a
.Xr gcc 1
built-in function that returns the size of the
.Fa ptr
object if known at compile time and the object does not have any side
effects.
.Sh RETURN VALUES
If the size of the object is not known or it has side effects the
.Fn __builtin_object_size
function returns:
.Bl -tag -width (size_t)-1
.It Dv (size_t)-1
for
.Fa type
.Dv 0
and
.Dv 1 .
.It Dv (size_t)0
for
.Fa type
.Dv 2
and
.Dv 3 .
.El
.Pp
If the size of the object is known, then the
.Fn __builtin_object_size
function returns the maximum size of all the objects that the compiler
knows that they can be pointed to by
.Fa ptr
when
.Fa type
.Dv \*[Am] 2 == 0 ,
and the minimum size when
.Fa type
.Dv \*[Am] 2 != 0 .
.Sh SEE ALSO
.Xr gcc 1 ,
.Xr ssp 3
.Sh HISTORY
The
.Fn __builtin_object_size
appeared in gcc 4.1.