freebsd-skq/contrib/elftoolchain/libdwarf/dwarf_get_aranges.3
emaste b54d7a9715 Update to ELF Tool Chain r3668
Highlights:
- Make sure that only TLS sections are sorted into TLS segment.
- Fixed multiple errors in "Section to Segment mapping".
- Man page updates
- ar improvements
- elfcopy: avoid filter_reloc uninitialized variable for rela
- elfcopy: avoid stripping relocations from static binaries
- readelf: avoid printing directory in front of absolute path
- readelf: add NT_FREEBSD_FEATURE_CTL FreeBSD note type
- test improvements

NOTES:

Some of these changes originated in FreeBSD and simply reduce diffs
between contrib and vendor.

ELF Tool Chain ar is not (currently) used in FreeBSD, and there are
improvements in both FreeBSD and ELF Tool Chain ar that are not in
the other.

Sponsored by:	The FreeBSD Foundation
2019-01-10 14:35:23 +00:00

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4.0 KiB
Groff

.\" Copyright (c) 2011 Kai Wang
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" documentation and/or other materials provided with the distribution.
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" 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
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.\" $Id: dwarf_get_aranges.3 3644 2018-10-15 19:55:01Z jkoshy $
.\"
.Dd November 9, 2011
.Dt DWARF_GET_ARANGES 3
.Os
.Sh NAME
.Nm dwarf_get_aranges
.Nd retrieve program address space mappings
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft int
.Fo dwarf_get_aranges
.Fa "Dwarf_Debug dbg"
.Fa "Dwarf_Arange **ar_list"
.Fa "Dwarf_Signed *ar_cnt"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
The function
.Fn dwarf_get_aranges
retrieves address range information from the
.Dq ".debug_aranges"
DWARF section.
Information about address ranges is returned using opaque descriptors
of type
.Vt Dwarf_Arange ,
.Pp
Argument
.Ar dbg
should reference a DWARF debug context allocated using
.Xr dwarf_init 3 .
.Pp
Argument
.Ar ar_list
should point to a location which will be set to a pointer to an array
of
.Vt Dwarf_Arange
descriptors.
.Pp
Argument
.Ar ar_cnt
should point to a location which will be set to the number of
descriptors returned.
.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 area used for the array returned in argument
.Ar ar_list
is owned by
.Lb libdwarf .
Application code should not attempt to directly free this area.
Portable applications should instead use
.Xr dwarf_dealloc 3
to indicate that the memory area may be freed.
.Sh RETURN VALUES
Function
.Fn dwarf_get_aranges
returns
.Dv DW_DLV_OK
when it succeeds.
It returns
.Dv DW_DLV_NO_ENTRY
if there is no
.Dq ".debug_aranges"
section associated with the specified debugging context.
In case of an error, it returns
.Dv DW_DLV_ERROR
and sets the argument
.Ar err .
.Sh EXAMPLES
To loop through all the address lookup table entries, use:
.Bd -literal -offset indent
Dwarf_Debug dbg;
Dwarf_Addr start;
Dwarf_Arange *aranges;
Dwarf_Off die_off;
Dwarf_Signed i, cnt;
Dwarf_Unsigned length;
Dwarf_Error de;
if (dwarf_get_aranges(dbg, &aranges, &cnt, &de) != DW_DLV_OK)
errx(EXIT_FAILURE, "dwarf_get_aranges: %s",
dwarf_errmsg(de));
for (i = 0; i < cnt; i++) {
if (dwarf_get_arange_info(aranges[i], &start, &length,
&die_off, &de) != DW_DLV_OK) {
warnx("dwarf_get_arange_info: %s",
dwarf_errmsg(de));
continue;
}
/* Do something with the returned information. */
}
.Ed
.Sh ERRORS
Function
.Fn dwarf_get_aranges
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 ar_list
or
.Ar ar_cnt
was NULL.
.It Bq Er DW_DLE_NO_ENTRY
The debugging context
.Ar dbg
did not contain a
.Dq ".debug_aranges"
string section.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_get_arange 3 ,
.Xr dwarf_get_arange_cu_header_offset 3 ,
.Xr dwarf_get_arange_info 3 ,
.Xr dwarf_get_cu_die_offset 3