.\"	$NetBSD: dwarf_add_AT_dataref.3,v 1.3 2016/02/20 02:43:41 christos Exp $
.\"
.\" Copyright (c) 2011 Kai Wang
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.\" Id: dwarf_add_AT_dataref.3 2072 2011-10-27 03:26:49Z jkoshy 
.\"
.Dd September 4, 2011
.Os
.Dt DWARF_ADD_AT_DATAREF 3
.Sh NAME
.Nm dwarf_add_AT_dataref
.Nd create an attribute descriptor for a relocatable address
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft "Dwarf_P_Attribute"
.Fo dwarf_add_AT_dataref
.Fa "Dwarf_P_Debug dbg"
.Fa "Dwarf_P_Die die"
.Fa "Dwarf_Half attr"
.Fa "Dwarf_Unsigned pc_value"
.Fa "Dwarf_Unsigned sym_index"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
Function
.Fn dwarf_add_AT_dataref
creates an attribute descriptor for a relocatable address and attaches
it to the debugging information entry referenced by argument
.Ar die .
.Pp
If flag
.Dv DW_DLC_SIZE_64
is set, the address value will be 8 bytes in size and of the DWARF form
.Dv DW_FORM_data8 .
Otherwise, the address value will be 4 bytes in size and of the DWARF form
.Dv DW_FORM_data4 .
.Pp
Argument
.Ar dbg
should reference a DWARF producer instance allocated using
.Xr dwarf_producer_init 3
or
.Xr dwarf_producer_init_b 3 .
.Pp
Argument
.Ar die
should reference a debugging information entry allocated using
.Xr dwarf_new_die 3 .
.Pp
Argument
.Ar attr
specifies the attribute code of the created attribute descriptor.
.Pp
Argument
.Ar pc_value
specifies the value of the relocatable address.
.Pp
Argument
.Ar sym_index
specifies the ELF symbol index of the symbol to be used for
relocation.
.Pp
If argument
.Ar err
is not NULL, it will be used to store error information in case
of an error.
.Sh RETURN VALUES
On success, function
.Fn dwarf_add_AT_dataref
returns the created attribute descriptor.
In case of an error, function
.Fn dwarf_add_AT_dataref
returns
.Dv DW_DLV_BADADDR
and sets the argument
.Ar err .
.Sh ERRORS
Function
.Fn dwarf_add_AT_dataref
can fail with:
.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
.It Bq Er DW_DLE_ARGUMENT
Either of the arguments
.Ar dbg
or
.Ar die
was NULL.
.It Bq Er DW_DLE_MEMORY
An out of memory condition was encountered during the execution of the
function.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_add_AT_reference 3 ,
.Xr dwarf_add_AT_ref_address 3 ,
.Xr dwarf_add_AT_signed_const 3 ,
.Xr dwarf_add_AT_unsigned_const 3 ,
.Xr dwarf_new_die 3 ,
.Xr dwarf_producer_init 3 ,
.Xr dwarf_producer_init_b 3