xref: /freebsd/contrib/elftoolchain/libdwarf/dwarf_get_arange_info.3 (revision ae500c1ff8974130f7f2692772cf288b90349e0d)
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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