1  /* System dependent definitions for run-time dynamic loading.
       2     Copyright (C) 1996-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #ifndef _DLFCN_H
      20  # error "Never use <bits/dlfcn.h> directly; include <dlfcn.h> instead."
      21  #endif
      22  
      23  /* The MODE argument to `dlopen' contains one of the following: */
      24  #define RTLD_LAZY	0x00001	/* Lazy function call binding.  */
      25  #define RTLD_NOW	0x00002	/* Immediate function call binding.  */
      26  #define	RTLD_BINDING_MASK   0x3	/* Mask of binding time value.  */
      27  #define RTLD_NOLOAD	0x00004	/* Do not load the object.  */
      28  #define RTLD_DEEPBIND	0x00008	/* Use deep binding.  */
      29  
      30  /* If the following bit is set in the MODE argument to `dlopen',
      31     the symbols of the loaded object and its dependencies are made
      32     visible as if the object were linked directly into the program.  */
      33  #define RTLD_GLOBAL	0x00100
      34  
      35  /* Unix98 demands the following flag which is the inverse to RTLD_GLOBAL.
      36     The implementation does this by default and so we can define the
      37     value to zero.  */
      38  #define RTLD_LOCAL	0
      39  
      40  /* Do not delete object when closed.  */
      41  #define RTLD_NODELETE	0x01000
      42  
      43  #ifdef __USE_GNU
      44  /* To support profiling of shared objects it is a good idea to call
      45     the function found using `dlsym' using the following macro since
      46     these calls do not use the PLT.  But this would mean the dynamic
      47     loader has no chance to find out when the function is called.  The
      48     macro applies the necessary magic so that profiling is possible.
      49     Rewrite
      50  	foo = (*fctp) (arg1, arg2);
      51     into
      52          foo = DL_CALL_FCT (fctp, (arg1, arg2));
      53  */
      54  # define DL_CALL_FCT(fctp, args) \
      55    (_dl_mcount_wrapper_check ((void *) (fctp)), (*(fctp)) args)
      56  
      57  __BEGIN_DECLS
      58  
      59  /* This function calls the profiling functions.  */
      60  extern void _dl_mcount_wrapper_check (void *__selfpc) __THROW;
      61  
      62  __END_DECLS
      63  
      64  #endif