include/dlfcn.h

   1 /* User functions for run-time dynamic loading.
   2    Copyright (C) 1995-2001,2003,2004,2006,2009 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _DLFCN_H
  20 #define _DLFCN_H 1
  21
  22 #include <features.h>
  23 #define __need_size_t
  24 #include <stddef.h>
  25
  26 /* Collect various system dependent definitions and declarations.  */
  27 #include <bits/dlfcn.h>
  28
  29 /* Internally used flag.  */
  30 #define __RTLD_SECURE   0x04000000 /* Apply additional security checks.  */
  31
  32
  33 #ifdef __USE_GNU
  34 /* If the first argument of `dlsym' or `dlvsym' is set to RTLD_NEXT
  35    the run-time address of the symbol called NAME in the next shared
  36    object is returned.  The "next" relation is defined by the order
  37    the shared objects were loaded.  */
  38 # define RTLD_NEXT      ((void *) -1l)
  39
  40 /* If the first argument to `dlsym' or `dlvsym' is set to RTLD_DEFAULT
  41    the run-time address of the symbol called NAME in the global scope
  42    is returned.  */
  43 # define RTLD_DEFAULT   ((void *) 0)
  44
  45
  46 # if 0 /* uClibc doesnt support this */
  47 /* Type for namespace indeces.  */
  48 typedef long int Lmid_t;
  49
  50 /* Special namespace ID values.  */
  51 # define LM_ID_BASE     0       /* Initial namespace.  */
  52 # define LM_ID_NEWLM    -1      /* For dlmopen: request new namespace.  */
  53 # endif
  54 #endif
  55
  56
  57 __BEGIN_DECLS
  58
  59 /* Open the shared object FILE and map it in; return a handle that can be
  60    passed to `dlsym' to get symbol values from it.  */
  61 extern void *dlopen (const char *__file, int __mode) __THROWNL;
  62
  63 /* Unmap and close a shared object opened by `dlopen'.
  64    The handle cannot be used again after calling `dlclose'.  */
  65 extern int dlclose (void *__handle) __THROWNL __nonnull ((1));
  66
  67 /* Find the run-time address in the shared object HANDLE refers to
  68    of the symbol called NAME.  */
  69 extern void *dlsym (void *__restrict __handle,
  70                     const char *__restrict __name) __THROW __nonnull ((2));
  71
  72 #if 0 /*def __USE_GNU*/
  73 /* Like `dlopen', but request object to be allocated in a new namespace.  */
  74 extern void *dlmopen (Lmid_t __nsid, const char *__file, int __mode) __THROWNL;
  75
  76 /* Find the run-time address in the shared object HANDLE refers to
  77    of the symbol called NAME with VERSION.  */
  78 extern void *dlvsym (void *__restrict __handle,
  79                      const char *__restrict __name,
  80                      const char *__restrict __version)
  81      __THROW __nonnull ((2, 3));
  82 #endif
  83
  84 /* When any of the above functions fails, call this function
  85    to return a string describing the error.  Each call resets
  86    the error string so that a following call returns null.  */
  87 extern char *dlerror (void) __THROW;
  88
  89
  90 #ifdef __USE_GNU
  91 /* Structure containing information about object searched using
  92    `dladdr'.  */
  93 typedef struct
  94 {
  95   const char *dli_fname;        /* File name of defining object.  */
  96   void *dli_fbase;              /* Load address of that object.  */
  97   const char *dli_sname;        /* Name of nearest symbol.  */
  98   void *dli_saddr;              /* Exact value of nearest symbol.  */
  99 } Dl_info;
 100
 101 /* Fill in *INFO with the following information about ADDRESS.
 102    Returns 0 iff no shared object's segments contain that address.  */
 103 extern int dladdr (const void *__address, Dl_info *__info)
 104      __THROW __nonnull ((2));
 105
 106 #if 0 /* not supported by uClibc */
 107 /* Same as `dladdr', but additionally sets *EXTRA_INFO according to FLAGS.  */
 108 extern int dladdr1 (const void *__address, Dl_info *__info,
 109                     void **__extra_info, int __flags) __THROW __nonnull ((2));
 110
 111 /* These are the possible values for the FLAGS argument to `dladdr1'.
 112    This indicates what extra information is stored at *EXTRA_INFO.
 113    It may also be zero, in which case the EXTRA_INFO argument is not used.  */
 114 enum
 115   {
 116     /* Matching symbol table entry (const ElfNN_Sym *).  */
 117     RTLD_DL_SYMENT = 1,
 118
 119     /* The object containing the address (struct link_map *).  */
 120     RTLD_DL_LINKMAP = 2
 121   };
 122
 123
 124 /* Get information about the shared object HANDLE refers to.
 125    REQUEST is from among the values below, and determines the use of ARG.
 126
 127    On success, returns zero.  On failure, returns -1 and records an error
 128    message to be fetched with `dlerror'.  */
 129 extern int dlinfo (void *__restrict __handle,
 130                    int __request, void *__restrict __arg)
 131      __THROW __nonnull ((1, 3));
 132
 133 /* These are the possible values for the REQUEST argument to `dlinfo'.  */
 134 enum
 135   {
 136     /* Treat ARG as `lmid_t *'; store namespace ID for HANDLE there.  */
 137     RTLD_DI_LMID = 1,
 138
 139     /* Treat ARG as `struct link_map **';
 140        store the `struct link_map *' for HANDLE there.  */
 141     RTLD_DI_LINKMAP = 2,
 142
 143     RTLD_DI_CONFIGADDR = 3,     /* Unsupported, defined by Solaris.  */
 144
 145     /* Treat ARG as `Dl_serinfo *' (see below), and fill in to describe the
 146        directories that will be searched for dependencies of this object.
 147        RTLD_DI_SERINFOSIZE fills in just the `dls_cnt' and `dls_size'
 148        entries to indicate the size of the buffer that must be passed to
 149        RTLD_DI_SERINFO to fill in the full information.  */
 150     RTLD_DI_SERINFO = 4,
 151     RTLD_DI_SERINFOSIZE = 5,
 152
 153     /* Treat ARG as `char *', and store there the directory name used to
 154        expand $ORIGIN in this shared object's dependency file names.  */
 155     RTLD_DI_ORIGIN = 6,
 156
 157     RTLD_DI_PROFILENAME = 7,    /* Unsupported, defined by Solaris.  */
 158     RTLD_DI_PROFILEOUT = 8,     /* Unsupported, defined by Solaris.  */
 159
 160     /* Treat ARG as `size_t *', and store there the TLS module ID
 161        of this object's PT_TLS segment, as used in TLS relocations;
 162        store zero if this object does not define a PT_TLS segment.  */
 163     RTLD_DI_TLS_MODID = 9,
 164
 165     /* Treat ARG as `void **', and store there a pointer to the calling
 166        thread's TLS block corresponding to this object's PT_TLS segment.
 167        Store a null pointer if this object does not define a PT_TLS
 168        segment, or if the calling thread has not allocated a block for it.  */
 169     RTLD_DI_TLS_DATA = 10,
 170
 171     RTLD_DI_MAX = 10
 172   };
 173
 174
 175 /* This is the type of elements in `Dl_serinfo', below.
 176    The `dls_name' member points to space in the buffer passed to `dlinfo'.  */
 177 typedef struct
 178 {
 179   char *dls_name;               /* Name of library search path directory.  */
 180   unsigned int dls_flags;       /* Indicates where this directory came from. */
 181 } Dl_serpath;
 182
 183 /* This is the structure that must be passed (by reference) to `dlinfo' for
 184    the RTLD_DI_SERINFO and RTLD_DI_SERINFOSIZE requests.  */
 185 typedef struct
 186 {
 187   size_t dls_size;              /* Size in bytes of the whole buffer.  */
 188   unsigned int dls_cnt;         /* Number of elements in `dls_serpath'.  */
 189   Dl_serpath dls_serpath[1];    /* Actually longer, dls_cnt elements.  */
 190 } Dl_serinfo;
 191 #endif
 192 #endif /* __USE_GNU */
 193
 194
 195 __END_DECLS
 196
 197 #endif  /* dlfcn.h */