.\" 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_aranges.3 3644 2018-10-15 19:55:01Z jkoshy $
.\"
.Dd November 9, 2011
.Dt DWARF_GET_ARANGES 3
.Os
.Sh NAME
.Nm dwarf_get_aranges
.Nd retrieve program address space mappings
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft int
.Fo dwarf_get_aranges
.Fa "Dwarf_Debug dbg"
.Fa "Dwarf_Arange **ar_list"
.Fa "Dwarf_Signed *ar_cnt"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
The function
.Fn dwarf_get_aranges
retrieves address range information from the
.Dq ".debug_aranges"
DWARF section.
Information about address ranges is returned using opaque descriptors
of type
.Vt Dwarf_Arange ,
.Pp
Argument
.Ar dbg
should reference a DWARF debug context allocated using
.Xr dwarf_init 3 .
.Pp
Argument
.Ar ar_list
should point to a location which will be set to a pointer to an array
of
.Vt Dwarf_Arange
descriptors.
.Pp
Argument
.Ar ar_cnt
should point to a location which will be set to the number of
descriptors returned.
.Pp
If argument
.Ar err
is not NULL, it will be used to store error information in case of an
error.
.Ss Memory Management
The memory area used for the array returned in argument
.Ar ar_list
is owned by
.Lb libdwarf .
Application code should not attempt to directly free this area.
Portable applications should instead use
.Xr dwarf_dealloc 3
to indicate that the memory area may be freed.
.Sh RETURN VALUES
Function
.Fn dwarf_get_aranges
returns
.Dv DW_DLV_OK
when it succeeds.
It returns
.Dv DW_DLV_NO_ENTRY
if there is no
.Dq ".debug_aranges"
section associated with the specified debugging context.
In case of an error, it returns
.Dv DW_DLV_ERROR
and sets the argument
.Ar err .
.Sh EXAMPLES
To loop through all the address lookup table entries, use:
.Bd -literal -offset indent
Dwarf_Debug dbg;
Dwarf_Addr start;
Dwarf_Arange *aranges;
Dwarf_Off die_off;
Dwarf_Signed i, cnt;
Dwarf_Unsigned length;
Dwarf_Error de;

if (dwarf_get_aranges(dbg, &aranges, &cnt, &de) != DW_DLV_OK)
	errx(EXIT_FAILURE, "dwarf_get_aranges: %s",
	    dwarf_errmsg(de));

for (i = 0; i < cnt; i++) {
	if (dwarf_get_arange_info(aranges[i], &start, &length,
	    &die_off, &de) != DW_DLV_OK) {
		warnx("dwarf_get_arange_info: %s",
		    dwarf_errmsg(de));
		continue;
	}
	/* Do something with the returned information. */
}
.Ed
.Sh ERRORS
Function
.Fn dwarf_get_aranges
can fail with:
.Bl -tag -width ".Bq Er DW_DLE_NO_ENTRY"
.It Bq Er DW_DLE_ARGUMENT
One of the arguments
.Ar dbg ,
.Ar ar_list
or
.Ar ar_cnt
was NULL.
.It Bq Er DW_DLE_NO_ENTRY
The debugging context
.Ar dbg
did not contain a
.Dq ".debug_aranges"
string section.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_get_arange 3 ,
.Xr dwarf_get_arange_cu_header_offset 3 ,
.Xr dwarf_get_arange_info 3 ,
.Xr dwarf_get_cu_die_offset 3