text: /*
   * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
   * Portions Copyright (c) 1990 The Regents of the University of California.
   * All rights reserved.
   *
   * src/backend/port/dynloader/freebsd.c
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *	  notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *	  notice, this list of conditions and the following disclaimer in the
   *	  documentation and/or other materials provided with the distribution.
   * 3. Neither the name of the University nor the names of its contributors
   *	  may be used to endorse or promote products derived from this software
   *	  without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  #if defined(LIBC_SCCS) && !defined(lint)
  static char sccsid[] = "@(#)dl.c	5.4 (Berkeley) 2/23/91";
  #endif							/* LIBC_SCCS and not lint */
  
  #include "postgres.h"
  
  #include <nlist.h>
  #include <link.h>
  #include <dlfcn.h>
  
  #include "dynloader.h"
  
  static char error_message[BUFSIZ];
  
  char *
  BSD44_derived_dlerror(void)
  {
  	static session_local char ret[BUFSIZ];
  
  	strcpy(ret, error_message);
  	error_message[0] = 0;
  	return (ret[0] == 0) ? NULL : ret;
  }
  
  void *
  BSD44_derived_dlopen(const char *file, int num)
  {
  #if !defined(HAVE_DLOPEN)
  	snprintf(error_message, sizeof(error_message),
  			 "dlopen (%s) not supported", file);
  	return NULL;
  #else
  	void	   *vp;
  
  	if ((vp = dlopen((char *) file, num)) == NULL)
  		snprintf(error_message, sizeof(error_message),
  				 "dlopen (%s) failed: %s", file, dlerror());
  	return vp;
  #endif
  }
  
  void *
  BSD44_derived_dlsym(void *handle, const char *name)
  {
  #if !defined(HAVE_DLOPEN)
  	snprintf(error_message, sizeof(error_message),
  			 "dlsym (%s) failed", name);
  	return NULL;
  #else
  	void	   *vp;
  
  #ifndef __ELF__
  	char		buf[BUFSIZ];
  
  	if (*name != '_')
  	{
  		snprintf(buf, sizeof(buf), "_%s", name);
  		name = buf;
  	}
  #endif							/* !__ELF__ */
  	if ((vp = dlsym(handle, (char *) name)) == NULL)
  		snprintf(error_message, sizeof(error_message),
  				 "dlsym (%s) failed", name);
  	return vp;
  #endif
  }
  
  void
  BSD44_derived_dlclose(void *handle)
  {
  #if defined(HAVE_DLOPEN)
  	dlclose(handle);
  #endif
  }
  