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

   1 /*
   2  *              Portable API for dynamic loading
   3  *
   4  *  Assuming modules are enabled on modern systems...  *Yes*, the
   5  *  preprocessor macro checks could be more precise.  I don't care.
   6  *
   7  *  If you think the abstraction is too leaky use libltdl (libtool),
   8  *  don't reinvent the wheel by fixing this one.
   9  */
  10
  11 #include "dynlib.h"
  12
  13 /*
  14  *  Windows systems
  15  */
  16 #if defined(_WIN32)
  17
  18 #include <windows.h>
  19
  20 dynlib_handle_ptr dynlib_open (const char * path)
  21 {
  22
  23   return (dynlib_handle_ptr) LoadLibrary (path);
  24 }
  25
  26 void * dynlib_sym (dynlib_handle_ptr h, const char * sym)
  27 {
  28   return GetProcAddress ((HMODULE) h, sym);
  29 }
  30
  31 bool dynlib_addr (void *ptr, const char **path, const char **sym)
  32 {
  33   return false;  /* not implemented */
  34 }
  35
  36 const char * dynlib_error (void)
  37 {
  38   /* TODO: use GetLastError(), FormatMessage(), ... */
  39   return "Can't load DLL";
  40 }
  41
  42 int dynlib_close (dynlib_handle_ptr h)
  43 {
  44   return FreeLibrary ((HMODULE) h) != 0;
  45 }
  46
  47
  48 /*
  49  *  POSIX systems
  50  */
  51 #elif defined(HAVE_UNISTD_H)
  52
  53 #include <dlfcn.h>
  54
  55 dynlib_handle_ptr dynlib_open (const char * path)
  56 {
  57   return dlopen (path, RTLD_LAZY);
  58 }
  59
  60 void * dynlib_sym (dynlib_handle_ptr h, const char * sym)
  61 {
  62   return dlsym (h, sym);
  63 }
  64
  65 bool dynlib_addr (void *ptr, const char **path, const char **sym)
  66 {
  67 #ifdef HAVE_DLADDR
  68   Dl_info info;
  69   if (dladdr (ptr, &info) != 0 && info.dli_fname != NULL && info.dli_sname != NULL)
  70     {
  71       *path = info.dli_fname;
  72       *sym = info.dli_sname;
  73       return true;
  74     }
  75 #endif
  76   return false;
  77 }
  78
  79 const char * dynlib_error (void)
  80 {
  81   return dlerror ();
  82 }
  83
  84 int dynlib_close (dynlib_handle_ptr h)
  85 {
  86   return dlclose (h) == 0;
  87 }
  88
  89 #else
  90
  91 #error "No dynamic loading for this system"
  92
  93 #endif