1.\" $NetBSD: dwarf_get_loclist_entry.3,v 1.2 2014/03/09 16:58:04 christos Exp $ 2.\" 3.\" Copyright (c) 2011 Kai Wang 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.\" Id: dwarf_get_loclist_entry.3 2071 2011-10-27 03:20:00Z jkoshy 28.\" 29.Dd July 6, 2011 30.Os 31.Dt DWARF_GET_LOCLIST_ENTRY 3 32.Sh NAME 33.Nm dwarf_get_loclist_entry 34.Nd retrieve DWARF location list entry 35.Sh LIBRARY 36.Lb libdwarf 37.Sh SYNOPSIS 38.In libdwarf.h 39.Ft int 40.Fo dwarf_get_loclist_entry 41.Fa "Dwarf_Debug dbg" 42.Fa "Dwarf_Unsigned offset" 43.Fa "Dwarf_Addr *hipc" 44.Fa "Dwarf_Addr *lopc" 45.Fa "Dwarf_Ptr *data" 46.Fa "Dwarf_Unsigned *entry_len" 47.Fa "Dwarf_Unsigned *next_entry" 48.Fa "Dwarf_Error *err" 49.Fc 50.Sh DESCRIPTION 51Function 52.Fn dwarf_get_loclist_entry 53retrieves a location list entry from the DWARF section 54.Dq ".debug_loc" . 55.Pp 56Argument 57.Ar dbg 58should reference a DWARF debug context allocated using 59.Xr dwarf_init 3 . 60.Pp 61Argument 62.Ar offset 63is an offset, relative to the 64.Dq ".debug_loc" 65section, to the start of the desired location list entry. 66.Pp 67Argument 68.Ar hipc 69should point to a location which will hold the offset, relative to the 70base address of the location list entry, of the highest program 71counter value for the entry. 72.Pp 73Argument 74.Ar lowpc 75should point to a location which will hold the offset, relative to the 76base address of the location list entry, of the lowest program counter 77value for the entry. 78.Pp 79Argument 80.Ar data 81should point to a location which will be set to a pointer to the location 82list data. 83.Pp 84Argument 85.Ar entry_len 86should point to a location which will hold the length in bytes of the 87location list data returned in argument 88.Ar data . 89.Pp 90Argument 91.Ar next_entry 92should point to a location which will hold the offset of the next 93location list entry. 94.Pp 95If argument 96.Ar err 97is not NULL, it will be used to store error information in case 98of an error. 99.Sh RETURN VALUES 100Function 101.Fn dwarf_get_loclist_entry 102returns 103.Dv DW_DLV_OK 104when it succeeds. 105It returns 106.Dv DW_DLV_NO_ENTRY 107if there is no location list at the specified offset 108.Ar offset . 109In case of an error, it returns 110.Dv DW_DLV_ERROR 111and sets the argument 112.Ar err . 113.Sh ERRORS 114Function 115.Fn dwarf_get_loclist_entry 116can fail with: 117.Bl -tag -width ".Bq Er DW_DLE_NO_ENTRY" 118.It Bq Er DW_DLE_ARGUMENT 119One of the arguments 120.Ar dbg , 121.Ar hipc , 122.Ar lopc , 123.Ar data , 124.Ar entry_len 125or 126.Ar next_entry 127was NULL. 128.It Bq Er DW_DLE_NO_ENTRY 129There is no location list at the specified offset 130.Ar offset . 131.El 132.Sh EXAMPLE 133To iterate through all the location list entries in the 134.Dq ".debug_loc" 135section, use: 136.Bd -literal -offset indent 137Dwarf_Debug dbg; 138Dwarf_Unsigned off, len, next; 139Dwarf_Addr hipc, lopc; 140Dwarf_Ptr data; 141Dwarf_Error de; 142int ret; 143 144off = 0; 145while ((ret = dwarf_get_loclist_entry(dbg, off, &hipc, &lopc, &data, 146 &len, &next, &de)) == DW_DLV_OK) { 147 /* ... use loclist entry ... */ 148 off = next; 149} 150if (ret == DW_DLV_ERROR) 151 warnx("dwarf_get_loclist_entry failed: %s", dwarf_errmsg(de)); 152.Ed 153.Sh SEE ALSO 154.Xr dwarf 3 , 155.Xr dwarf_loclist 3 , 156.Xr dwarf_loclist_n 3 , 157.Xr dwarf_loclist_from_expr 3 , 158.Xr dwarf_loclist_from_expr_a 3 159