1.\" $NetBSD: dwarf_get_str.3,v 1.6 2024/03/03 17:37:31 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_str.3 3963 2022-03-12 16:07:32Z jkoshy 28.\" 29.Dd April 3, 2011 30.Dt DWARF_GET_STR 3 31.Os 32.Sh NAME 33.Nm dwarf_get_str 34.Nd retrieve a string from the DWARF string section 35.Sh LIBRARY 36.Lb libdwarf 37.Sh SYNOPSIS 38.In libdwarf.h 39.Ft int 40.Fo dwarf_get_str 41.Fa "Dwarf_Debug dbg" 42.Fa "Dwarf_Off offset" 43.Fa "char **string" 44.Fa "Dwarf_Signed *len" 45.Fa "Dwarf_Error *err" 46.Fc 47.Sh DESCRIPTION 48Function 49.Fn dwarf_get_str 50retrieves a NUL-terminated string from the DWARF string section 51.Dq ".debug_str" . 52.Pp 53Argument 54.Fa dbg 55should reference a DWARF debug context allocated using 56.Xr dwarf_init 3 . 57.Pp 58Argument 59.Fa offset 60should be an offset, relative to the 61.Dq ".debug_str" 62section, specifying the start of the desired string. 63.Pp 64Argument 65.Fa string 66should point to a location which will hold a returned 67pointer to a NUL-terminated string. 68.Pp 69Argument 70.Fa len 71should point to a location which will hold the length 72of the returned string. 73The returned length does not include the space needed for 74the NUL-terminator. 75.Pp 76If argument 77.Fa err 78is not 79.Dv NULL , 80it will be used to store error information in case of an error. 81.Sh RETURN VALUES 82Function 83.Fn dwarf_get_str 84returns 85.Dv DW_DLV_OK 86when it succeeds. 87It returns 88.Dv DW_DLV_NO_ENTRY 89if there is no 90.Dq ".debug_str" 91section associated with the specified debugging context, 92or if the provided offset 93.Fa offset 94is at the very end of 95.Dq ".debug_str" 96section. 97In case of an error, it returns 98.Dv DW_DLV_ERROR 99and sets the argument 100.Fa err . 101.Sh EXAMPLES 102To retrieve all the strings in the DWARF string section, use: 103.Bd -literal -offset indent 104Dwarf_Debug dbg; 105Dwarf_Off offset; 106Dwarf_Signed len; 107Dwarf_Error de; 108char *str; 109int ret 110 111offset = 0; 112while ((ret = dwarf_get_str(dbg, offset, &str, &len, &de)) == 113 DW_DLV_OK) { 114 /* .. Use the retrieved string. .. */ 115 offset += len + 1; /* Account for the terminating NUL. */ 116} 117 118if (ret == DW_DLV_ERROR) 119 warnx("dwarf_get_str: %s", dwarf_errmsg(de)); 120.Ed 121.Sh ERRORS 122Function 123.Fn dwarf_get_str 124can fail with: 125.Bl -tag -width ".Bq Er DW_DLE_NO_ENTRY" 126.It Bq Er DW_DLE_ARGUMENT 127One of the arguments 128.Fa dbg , 129.Fa string 130or 131.Fa len 132was 133.Dv NULL . 134.It Bq Er DW_DLE_ARGUMENT 135Argument 136.Fa offset 137was out of range. 138.It Bq Er DW_DLE_NO_ENTRY 139The debugging context 140.Fa dbg 141did not contain a 142.Dq ".debug_str" 143string section. 144.It Bq Er DW_DLE_NO_ENTRY 145Argument 146.Fa offset 147was at the very end of the 148.Dq ".debug_str" 149section. 150.El 151.Sh SEE ALSO 152.Xr dwarf 3 , 153.Xr dwarf_init 3 154