1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
.\" 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_section_bytes.3 2071 2011-10-27 03:20:00Z jkoshy $
.\"
.Dd August 26, 2011
.Os
.Dt DWARF_GET_SECTION_BYTES 3
.Sh NAME
.Nm dwarf_get_section_bytes
.Nd retrieve ELF section byte streams
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft Dwarf_Ptr
.Fo dwarf_get_section_bytes
.Fa "Dwarf_P_Debug dbg"
.Fa "Dwarf_Signed dwarf_section"
.Fa "Dwarf_Signed *elf_section_index"
.Fa "Dwarf_Unsigned *length"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
Function
.Fn dwarf_get_section_bytes
returns the ELF section byte streams generated by a prior call
to function
.Xr dwarf_transform_to_disk_form 3 .
.Pp
Each call to function
.Fn dwarf_get_section_bytes
will return the byte stream for one ELF section.
The first call to this function will always return the first ELF
section, and the subsequent calls will return the rest of sections
in the order when they were generated, until the last one.
The total number of sections generated is returned by the function
.Xr dwarf_transform_to_disk_form 3 .
.Pp
Argument
.Ar dbg
should reference a DWARF producer instance allocated using the
functions
.Xr dwarf_producer_init 3
or
.Xr dwarf_producer_init_b 3 .
.Pp
Argument
.Ar dwarf_section
is currently ignored.
.Pp
Argument
.Ar elf_section_index
should point to a location which will be set to the section index value
of the returned ELF section.
.Pp
Argument
.Ar length
should point to a location which will hold the length in bytes of the
returned ELF section.
.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 areas used for the returned ELF section byte streams should
be freed using the function
.Fn dwarf_producer_finish .
.Sh RETURN VALUES
On success, function
.Fn dwarf_get_section_bytes
returns a pointer to a ELF section byte stream.
In case of an error, function
.Fn dwarf_get_section_bytes
will return NULL and set the argument
.Ar err .
.Sh ERRORS
Function
.Fn dwarf_get_section_bytes
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 elf_section_index ,
or
.Ar length
was NULL.
.It Bq Er DW_DLE_NO_ENTRY
There were no more ELF sections to retrieve, or the function was
called before a call to
.Xr dwarf_transform_to_disk_form 3 .
.El
.Sh EXAMPLES
To generate and retrieve ELF section byte streams, use:
.Bd -literal -offset indent
Dwarf_P_Debug dbg;
Dwarf_Signed count, i, sec_index;
Dwarf_Unsigned len;
Dwarf_Ptr bytes;
Dwarf_Error de;
/* ... Assume that `dbg' refers to a DWARF producer instance,
* and that application code has added DWARF debugging
* information to the producer instance. ...
*/
if ((count = dwarf_transform_to_disk_form(dbg, &de)) ==
DW_DLV_NOCOUNT) {
warnx("dwarf_transform_to_disk_form failed: %s",
dwarf_errmsg(-1));
return;
}
/* Retrieve section data. */
for (i = 0; i < count; i++) {
bytes = dwarf_get_section_bytes(dbg, i, &sec_index, &len,
&de);
if (bytes == NULL) {
warnx("dwarf_get_section_bytes failed: %s",
dwarf_errmsg(-1));
continue;
}
/* ... use the returned byte stream ... */
}
/* Release resources. */
dwarf_producer_finish(dbg, &de);
.Ed
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_reset_section_bytes 3 ,
.Xr dwarf_producer_finish 3 ,
.Xr dwarf_producer_init 3 ,
.Xr dwarf_producer_init_b 3 ,
.Xr dwarf_transform_to_disk_form 3
|
