xref: /freebsd/contrib/elftoolchain/libdwarf/dwarf_get_arange_info.3 (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1.\" Copyright (c) 2011 Kai Wang
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\"
13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23.\" SUCH DAMAGE.
24.\"
25.\" $Id: dwarf_get_arange_info.3 3644 2018-10-15 19:55:01Z jkoshy $
26.\"
27.Dd April 16, 2011
28.Dt DWARF_GET_ARANGE_INFO 3
29.Os
30.Sh NAME
31.Nm dwarf_get_arange_info
32.Nd extract address range information from a descriptor
33.Sh LIBRARY
34.Lb libdwarf
35.Sh SYNOPSIS
36.In libdwarf.h
37.Ft int
38.Fo dwarf_get_arange_info
39.Fa "Dwarf_Arange ar"
40.Fa "Dwarf_Addr *start"
41.Fa "Dwarf_Unsigned *length"
42.Fa "Dwarf_Off *cu_die_offset"
43.Fa "Dwarf_Error *err"
44.Fc
45.Sh DESCRIPTION
46Function
47.Fn dwarf_get_arange_info
48extracts address range information from a
49.Vt Dwarf_Arange
50descriptor.
51.Pp
52Argument
53.Ar ar
54should reference a valid
55.Vt Dwarf_Arange
56descriptor returned by function
57.Xr dwarf_get_aranges 3 .
58.Pp
59Argument
60.Ar start
61should point to a location which will hold the start value of the
62address range associated with the descriptor.
63.Pp
64Argument
65.Ar length
66should point to a location which will hold the length in bytes of the
67address range associated with the descriptor.
68.Pp
69Argument
70.Ar cu_die_offset
71should point to a location which will be set to an offset, relative to
72the
73.Dq ".debug_info"
74section, of the first debugging information entry in the compilation
75unit associated with argument
76.Ar ar .
77.Pp
78If argument
79.Ar err
80is not NULL, it will be used to store error information in case of an
81error.
82.Sh RETURN VALUES
83Function
84.Fn dwarf_get_arange_info
85returns
86.Dv DW_DLV_OK
87when it succeeds.
88In case of an error, it returns
89.Dv DW_DLV_ERROR
90and sets the argument
91.Ar err .
92.Sh EXAMPLES
93To loop through all the address lookup table entries, use:
94.Bd -literal -offset indent
95Dwarf_Debug dbg;
96Dwarf_Addr start;
97Dwarf_Arange *aranges;
98Dwarf_Off die_off;
99Dwarf_Signed i, cnt;
100Dwarf_Unsigned length;
101Dwarf_Error de;
102
103if (dwarf_get_aranges(dbg, &aranges, &cnt, &de) != DW_DLV_OK)
104	errx(EXIT_FAILURE, "dwarf_get_aranges: %s",
105	    dwarf_errmsg(de));
106for (i = 0; i < cnt; i++) {
107	if (dwarf_get_arange_info(aranges[i], &start, &length,
108	    &die_off, &de) != DW_DLV_OK) {
109		warnx("dwarf_get_arange_info: %s",
110		    dwarf_errmsg(de));
111		continue;
112	}
113	/* Do something with the returned information. */
114}
115.Ed
116.Sh ERRORS
117Function
118.Fn dwarf_get_arange_info
119can fail with:
120.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
121.It Bq Er DW_DLE_ARGUMENT
122One of the arguments
123.Ar ar ,
124.Ar start ,
125.Ar length
126or
127.Ar cu_die_offset
128was NULL.
129.El
130.Sh SEE ALSO
131.Xr dwarf 3 ,
132.Xr dwarf_get_arange 3 ,
133.Xr dwarf_get_arange_cu_header_offset 3 ,
134.Xr dwarf_get_aranges 3 ,
135.Xr dwarf_get_cu_die_offset 3
136