code.delx.au - gnu-emacs/blob - src/dynlib.c

   1 /* Portable API for dynamic loading.
   2
   3 Copyright 2015 Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software: you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation, either version 3 of the License, or
  10 (at your option) any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20
  21 /* Assume modules are enabled on modern systems...  *Yes*, the
  22    preprocessor macro checks could be more precise.  I don't care.
  23
  24    If you think the abstraction is too leaky use libltdl (libtool),
  25    don't reinvent the wheel by fixing this one.  */
  26
  27 #include "dynlib.h"
  28
  29 #if defined _WIN32
  30
  31 /* MS-Windows systems.  */
  32
  33 #include <windows.h>
  34
  35 dynlib_handle_ptr
  36 dynlib_open (const char *path)
  37 {
  38
  39   return (dynlib_handle_ptr) LoadLibrary (path);
  40 }
  41
  42 void *
  43 dynlib_sym (dynlib_handle_ptr h, const char *sym)
  44 {
  45   return GetProcAddress ((HMODULE) h, sym);
  46 }
  47
  48 bool
  49 dynlib_addr (void *ptr, const char **path, const char **sym)
  50 {
  51   return false;  /* not implemented */
  52 }
  53
  54 const char *
  55 dynlib_error (void)
  56 {
  57   /* TODO: use GetLastError(), FormatMessage(), ... */
  58   return "Can't load DLL";
  59 }
  60
  61 int
  62 dynlib_close (dynlib_handle_ptr h)
  63 {
  64   return FreeLibrary ((HMODULE) h) != 0;
  65 }
  66
  67 #elif defined HAVE_UNISTD_H
  68
  69 /* POSIX systems.  */
  70
  71 #include <dlfcn.h>
  72
  73 dynlib_handle_ptr
  74 dynlib_open (const char *path)
  75 {
  76   return dlopen (path, RTLD_LAZY);
  77 }
  78
  79 void *
  80 dynlib_sym (dynlib_handle_ptr h, const char *sym)
  81 {
  82   return dlsym (h, sym);
  83 }
  84
  85 bool
  86 dynlib_addr (void *ptr, const char **path, const char **sym)
  87 {
  88 #ifdef HAVE_DLADDR
  89   Dl_info info;
  90   if (dladdr (ptr, &info) && info.dli_fname && info.dli_sname)
  91     {
  92       *path = info.dli_fname;
  93       *sym = info.dli_sname;
  94       return true;
  95     }
  96 #endif
  97   return false;
  98 }
  99
 100 const char *
 101 dynlib_error (void)
 102 {
 103   return dlerror ();
 104 }
 105
 106 int
 107 dynlib_close (dynlib_handle_ptr h)
 108 {
 109   return dlclose (h) == 0;
 110 }
 111
 112 #else
 113
 114 #error "No dynamic loading for this system"
 115
 116 #endif