freebsd-dev/contrib/elftoolchain/libdwarf/dwarf_get_arange_info.3
Ed Maste ae500c1ff8 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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3.7 KiB
Groff

.\" Copyright (c) 2011 Kai Wang
.\" All rights reserved.
.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" $Id: dwarf_get_arange_info.3 3644 2018-10-15 19:55:01Z jkoshy $
.\"
.Dd April 16, 2011
.Dt DWARF_GET_ARANGE_INFO 3
.Os
.Sh NAME
.Nm dwarf_get_arange_info
.Nd extract address range information from a descriptor
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft int
.Fo dwarf_get_arange_info
.Fa "Dwarf_Arange ar"
.Fa "Dwarf_Addr *start"
.Fa "Dwarf_Unsigned *length"
.Fa "Dwarf_Off *cu_die_offset"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
Function
.Fn dwarf_get_arange_info
extracts address range information from a
.Vt Dwarf_Arange
descriptor.
.Pp
Argument
.Ar ar
should reference a valid
.Vt Dwarf_Arange
descriptor returned by function
.Xr dwarf_get_aranges 3 .
.Pp
Argument
.Ar start
should point to a location which will hold the start value of the
address range associated with the descriptor.
.Pp
Argument
.Ar length
should point to a location which will hold the length in bytes of the
address range associated with the descriptor.
.Pp
Argument
.Ar cu_die_offset
should point to a location which will be set to an offset, relative to
the
.Dq ".debug_info"
section, of the first debugging information entry in the compilation
unit associated with argument
.Ar ar .
.Pp
If argument
.Ar err
is not NULL, it will be used to store error information in case of an
error.
.Sh RETURN VALUES
Function
.Fn dwarf_get_arange_info
returns
.Dv DW_DLV_OK
when it succeeds.
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_arange_info
can fail with:
.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
.It Bq Er DW_DLE_ARGUMENT
One of the arguments
.Ar ar ,
.Ar start ,
.Ar length
or
.Ar cu_die_offset
was NULL.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_get_arange 3 ,
.Xr dwarf_get_arange_cu_header_offset 3 ,
.Xr dwarf_get_aranges 3 ,
.Xr dwarf_get_cu_die_offset 3