.\" Copyright (c) 2011 Kai Wang
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $Id: dwarf_get_form_class.3 3640 2018-10-14 14:09:13Z jkoshy $
.\"
.Dd June 26, 2011
.Dt DWARF_GET_FORM_CLASS 3
.Os
.Sh NAME
.Nm dwarf_get_form_class
.Nd retrieve the form class of an attribute
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft enum Dwarf_Form_Class
.Fo dwarf_get_form_class
.Fa "Dwarf_Half dwversion"
.Fa "Dwarf_Half attr"
.Fa "Dwarf_Half offset_size"
.Fa "Dwarf_Half form"
.Fc
.Sh DESCRIPTION
Function
.Fn dwarf_get_form_class
returns the class of the form of a DWARF attribute.
.Pp
Argument
.Ar dwversion
should specify the version number of DWARF specification
to use: 2 for DWARF2, 3 for DWARF3 and 4 for DWARF4.
.Pp
Argument
.Ar attr
should hold the attribute code of the attribute, i.e., one of the
.Li DW_AT_*
values defined in
.In libdwarf.h .
.Pp
Argument
.Ar offset_size
should hold the size of a DWARF offset for the relevant compilation
unit.
.Pp
Argument
.Ar form
should hold the form code of the attribute.
.Sh RETURN VALUES
On success, function
.Fn dwarf_get_form_class
returns the form class code, which is one of the
.Dv DW_FORM_CLASS_*
contants defined in header file
.In libdwarf.h .
If the function was not able to determine the form class of the
attribute, it returns the special form class code
.Dv DW_FORM_CLASS_UNKNOWN .
.Sh ERRORS
Function
.Fn dwarf_get_form_class
does not return an error.
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_attr 3 ,
.Xr dwarf_whatattr 3 ,
.Xr dwarf_whatform 3