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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 
     22 /*
     23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 /*
     28  * The sharable object /usr/lib/libldstab.so.1 is a link-editor
     29  * support library that was used to compress the stab table by
     30  * eliminating duplicate include file entries. The link-editor would
     31  * load it by default, unless the user explicitly supplied a support
     32  * library via the ld -S option. We publically documented this in the
     33  * Solaris Linkers and Libraries Manual (LLM), stating that users
     34  * who supply their own support libraries should also explicitly
     35  * add '-S libldstab.so.1' to their link commands in order to retain
     36  * the functionality it supplied.
     37  *
     38  * The original libldstab.so worked by forking a child process running
     39  * a program named sbfocus. sbfocus was delivered with the Sun
     40  * compilers, and was expected to be found in the users PATH.
     41  * As the compilers and the OSnet are delivered on disjoint schedules,
     42  * this division never worked very well. Modern versions of the
     43  * compilers supply their own support libraries directly as needed, and
     44  * no longer deliver a program named sbfocus. The link-editor no longer
     45  * loads libldstab.so.1 by default, and it is no longer documented in the LLM.
     46  *
     47  * The current version of /usr/lib/libldstab.so.1 is a stub that exists
     48  * solely for backward compatibility. In the case where an existing
     49  *  Makefile  still follows the old advice in the LLM and supplies
     50  * '-S libldstab.so.1' to the link-editor command line, this object
     51  * will be loaded. It specifies a support library version of
     52  * LD_SUP_VNONE, which indicates to the link-editor that it is
     53  * not needed and should be quietly unloaded. In this way, we
     54  * preserve the old documented interface without undue overhead.
     55  */
     56 
     57 
     58 #include <stdio.h>
     59 #include <link.h>
     60 #include "libld.h"
     61 
     62 
     63 /* ARGSUSED */
     64 uint_t
     65 #if	defined(_ELF64)
     66 ld_version64(uint_t version)
     67 #else
     68 ld_version(uint_t version)
     69 #endif
     70 {
     71 	/* LD_SUP_VNONE tells libld.so to ignore this support library */
     72 	return (LD_SUP_VNONE);
     73 }
     74