1.\"	$NetBSD: dwarf_get_aranges.3,v 1.2 2014/03/09 16:58:04 christos Exp $
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3.\" Copyright (c) 2011 Kai Wang
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27.\" Id: dwarf_get_aranges.3 2122 2011-11-09 15:35:14Z jkoshy
28.\"
29.Dd November 9, 2011
30.Os
31.Dt DWARF_GET_ARANGES 3
32.Sh NAME
33.Nm dwarf_get_aranges
34.Nd retrieve program address space mappings
35.Sh LIBRARY
36.Lb libdwarf
37.Sh SYNOPSIS
38.In libdwarf.h
39.Ft int
40.Fo dwarf_get_aranges
41.Fa "Dwarf_Debug dbg"
42.Fa "Dwarf_Arange **ar_list"
43.Fa "Dwarf_Signed *ar_cnt"
44.Fa "Dwarf_Error *err"
45.Fc
46.Sh DESCRIPTION
47The function
48.Fn dwarf_get_aranges
49retrieves address range information from the
50.Dq ".debug_aranges"
51DWARF section.
52Information about address ranges is returned using opaque descriptors
53of type
54.Vt Dwarf_Arange ,
55.Pp
56Argument
57.Ar dbg
58should reference a DWARF debug context allocated using
59.Xr dwarf_init 3 .
60.Pp
61Argument
62.Ar ar_list
63should point to a location which will be set to a pointer to an array
64of
65.Vt Dwarf_Arange
66descriptors.
67.Pp
68Argument
69.Ar ar_cnt
70should point to a location which will be set to the number of
71descriptors returned.
72.Pp
73If argument
74.Ar err
75is not NULL, it will be used to store error information in case of an
76error.
77.Ss Memory Management
78The memory area used for the array returned in argument
79.Ar ar_list
80is owned by
81.Lb libdwarf .
82Application code should not attempt to directly free this area.
83Portable applications should instead use
84.Xr dwarf_dealloc 3
85to indicate that the memory area may be freed.
86.Sh RETURN VALUES
87Function
88.Fn dwarf_get_aranges
89returns
90.Dv DW_DLV_OK
91when it succeeds.
92It returns
93.Dv DW_DLV_NO_ENTRY
94if there is no
95.Dq ".debug_aranges"
96section associated with the specified debugging context.
97In case of an error, it returns
98.Dv DW_DLV_ERROR
99and sets the argument
100.Ar err .
101.Sh ERRORS
102Function
103.Fn dwarf_get_aranges
104can fail with:
105.Bl -tag -width ".Bq Er DW_DLE_NO_ENTRY"
106.It Bq Er DW_DLE_ARGUMENT
107One of the arguments
108.Ar dbg ,
109.Ar ar_list
110or
111.Ar ar_cnt
112was NULL.
113.It Bq Er DW_DLE_NO_ENTRY
114The debugging context
115.Ar dbg
116did not contain a
117.Dq ".debug_aranges"
118string section.
119.El
120.Sh EXAMPLE
121To loop through all the address lookup table entries, use:
122.Bd -literal -offset indent
123Dwarf_Debug dbg;
124Dwarf_Addr start;
125Dwarf_Arange *aranges;
126Dwarf_Off die_off;
127Dwarf_Signed i, cnt;
128Dwarf_Unsigned length;
129Dwarf_Error de;
130
131if (dwarf_get_aranges(dbg, &aranges, &cnt, &de) != DW_DLV_OK)
132	errx(EXIT_FAILURE, "dwarf_get_aranges: %s",
133	    dwarf_errmsg(de));
134
135for (i = 0; i < cnt; i++) {
136	if (dwarf_get_arange_info(aranges[i], &start, &length,
137	    &die_off, &de) != DW_DLV_OK) {
138		warnx("dwarf_get_arange_info: %s",
139		    dwarf_errmsg(de));
140		continue;
141	}
142	/* Do something with the returned information. */
143}
144.Ed
145.Sh SEE ALSO
146.Xr dwarf 3 ,
147.Xr dwarf_get_arange 3 ,
148.Xr dwarf_get_arange_cu_header_offset 3 ,
149.Xr dwarf_get_arange_info 3 ,
150.Xr dwarf_get_cu_die_offset 3
151