1.\" Copyright (c) 2010 Joseph Koshy 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $Id: dwarf_formexprloc.3 2073 2011-10-27 03:30:47Z jkoshy $ 26.\" 27.Dd July 25, 2010 28.Os 29.Dt DWARF_FORMEXPRLOC 3 30.Sh NAME 31.Nm dwarf_formexprloc 32.Nd return information about a location expression 33.Sh LIBRARY 34.Lb libdwarf 35.Sh SYNOPSIS 36.In libdwarf.h 37.Ft int 38.Fo dwarf_formexprloc 39.Fa "Dwarf_Attribute attr" 40.Fa "Dwarf_Unsigned *retlen" 41.Fa "Dwarf_Ptr *retexpr" 42.Fa "Dwarf_Error *err" 43.Fc 44.Sh DESCRIPTION 45Function 46.Fn dwarf_formexprloc 47allows an application to retrieve the length and the bytes of a 48DWARF location expression. 49.Pp 50Argument 51.Ar attr 52should reference a DWARF attribute of the form 53.Dv DW_FORM_exprloc . 54Argument 55.Ar retlen 56should point to a location that will be set to the length of the 57location expression. 58Argument 59.Ar retexpr 60should point to a location that will be set to a pointer to the 61content of the location expression itself. 62.Pp 63If argument 64.Ar err 65is not NULL, it will be used to return an error descriptor in case 66of an error. 67.Ss Memory Management 68The application should not attempt to free the memory 69area referenced by the pointer returned in argument 70.Ar retexpr . 71.Sh RETURN VALUES 72Function 73.Fn dwarf_formexprloc 74returns 75.Dv DW_DLV_OK 76on success. 77In case of an error, it returns 78.Dv DW_DLV_ERROR 79and sets argument 80.Ar err . 81.Sh ERRORS 82Function 83.Fn dwarf_formexprloc 84may fail with the following errors: 85.Bl -tag -width ".Bq Er DW_DLE_ATTR_FORM_BAD" 86.It Bq Er DW_DLE_ARGUMENT 87One of arguments 88.Ar attr , 89.Ar retlen 90or 91.Ar retexpr 92was NULL. 93.It Bq Er DW_DLE_ATTR_FORM_BAD 94The attribute referenced by argument 95.Ar attr 96was not of form 97.Dv DW_FORM_exprloc . 98.El 99.Sh SEE ALSO 100.Xr dwarf 3 , 101.Xr dwarf_attr 3 , 102.Xr dwarf_formblock 3 , 103.Xr dwarf_formflag 3 , 104.Xr dwarf_formref 3 , 105.Xr dwarf_formsdata 3 , 106.Xr dwarf_formsig8 3 , 107.Xr dwarf_formstring 3 , 108.Xr dwarf_formudata 3 , 109.Xr dwarf_hasattr 3 110