xref: /netbsd-src/external/bsd/elftoolchain/dist/libdwarf/dwarf_get_arange_info.3 (revision 5ac3bc719ce6e70593039505b491894133237d12)
1.\"	$NetBSD: dwarf_get_arange_info.3,v 1.6 2024/03/03 17:37:31 christos Exp $
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3.\" Copyright (c) 2011 Kai Wang
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27.\" Id: dwarf_get_arange_info.3 3962 2022-03-12 15:56:10Z jkoshy
28.\"
29.Dd April 16, 2011
30.Dt DWARF_GET_ARANGE_INFO 3
31.Os
32.Sh NAME
33.Nm dwarf_get_arange_info
34.Nd extract address range information from a descriptor
35.Sh LIBRARY
36.Lb libdwarf
37.Sh SYNOPSIS
38.In libdwarf.h
39.Ft int
40.Fo dwarf_get_arange_info
41.Fa "Dwarf_Arange ar"
42.Fa "Dwarf_Addr *start"
43.Fa "Dwarf_Unsigned *length"
44.Fa "Dwarf_Off *cu_die_offset"
45.Fa "Dwarf_Error *err"
46.Fc
47.Sh DESCRIPTION
48Function
49.Fn dwarf_get_arange_info
50extracts address range information from a
51.Vt Dwarf_Arange
52descriptor.
53.Pp
54Argument
55.Fa ar
56should reference a valid
57.Vt Dwarf_Arange
58descriptor returned by function
59.Xr dwarf_get_aranges 3 .
60.Pp
61Argument
62.Fa start
63should point to a location which will hold the start value of the
64address range associated with the descriptor.
65.Pp
66Argument
67.Fa length
68should point to a location which will hold the length in bytes of the
69address range associated with the descriptor.
70.Pp
71Argument
72.Fa cu_die_offset
73should point to a location which will be set to an offset, relative to
74the
75.Dq ".debug_info"
76section, of the first debugging information entry in the compilation
77unit associated with argument
78.Fa ar .
79.Pp
80If argument
81.Fa err
82is not
83.Dv NULL ,
84it will be used to store error information in case of an error.
85.Sh RETURN VALUES
86Function
87.Fn dwarf_get_arange_info
88returns
89.Dv DW_DLV_OK
90when it succeeds.
91In case of an error, it returns
92.Dv DW_DLV_ERROR
93and sets the argument
94.Fa err .
95.Sh EXAMPLES
96To loop through all the address lookup table entries, use:
97.Bd -literal -offset indent
98Dwarf_Debug dbg;
99Dwarf_Addr start;
100Dwarf_Arange *aranges;
101Dwarf_Off die_off;
102Dwarf_Signed i, cnt;
103Dwarf_Unsigned length;
104Dwarf_Error de;
105
106if (dwarf_get_aranges(dbg, &aranges, &cnt, &de) != DW_DLV_OK)
107	errx(EXIT_FAILURE, "dwarf_get_aranges: %s",
108	    dwarf_errmsg(de));
109for (i = 0; i < cnt; i++) {
110	if (dwarf_get_arange_info(aranges[i], &start, &length,
111	    &die_off, &de) != DW_DLV_OK) {
112		warnx("dwarf_get_arange_info: %s",
113		    dwarf_errmsg(de));
114		continue;
115	}
116	/* Do something with the returned information. */
117}
118.Ed
119.Sh ERRORS
120Function
121.Fn dwarf_get_arange_info
122can fail with:
123.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
124.It Bq Er DW_DLE_ARGUMENT
125One of the arguments
126.Fa ar ,
127.Fa start ,
128.Fa length
129or
130.Fa cu_die_offset
131was
132.Dv NULL .
133.El
134.Sh SEE ALSO
135.Xr dwarf 3 ,
136.Xr dwarf_get_arange 3 ,
137.Xr dwarf_get_arange_cu_header_offset 3 ,
138.Xr dwarf_get_aranges 3 ,
139.Xr dwarf_get_cu_die_offset 3
140