src/backend/port/dynloader/win32.c

   1 /* $PostgreSQL$ */
   2
   3 #include "postgres.h"
   4
   5 char       *dlerror(void);
   6 int                     dlclose(void *handle);
   7 void       *dlsym(void *handle, const char *symbol);
   8 void       *dlopen(const char *path, int mode);
   9
  10 static char last_dyn_error[512];
  11
  12 static void
  13 set_dl_error(void)
  14 {
  15         DWORD           err = GetLastError();
  16
  17         if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS |
  18                                           FORMAT_MESSAGE_FROM_SYSTEM,
  19                                           NULL,
  20                                           err,
  21                                           MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT),
  22                                           last_dyn_error,
  23                                           sizeof(last_dyn_error) - 1,
  24                                           NULL) == 0)
  25         {
  26                 snprintf(last_dyn_error, sizeof(last_dyn_error) - 1,
  27                                  "unknown error %lu", err);
  28         }
  29 }
  30
  31 char *
  32 dlerror(void)
  33 {
  34         if (last_dyn_error[0])
  35                 return last_dyn_error;
  36         else
  37                 return NULL;
  38 }
  39
  40 int
  41 dlclose(void *handle)
  42 {
  43         if (!FreeLibrary((HMODULE) handle))
  44         {
  45                 set_dl_error();
  46                 return 1;
  47         }
  48         last_dyn_error[0] = 0;
  49         return 0;
  50 }
  51
  52 void *
  53 dlsym(void *handle, const char *symbol)
  54 {
  55         void       *ptr;
  56
  57         ptr = GetProcAddress((HMODULE) handle, symbol);
  58         if (!ptr)
  59         {
  60                 set_dl_error();
  61                 return NULL;
  62         }
  63         last_dyn_error[0] = 0;
  64         return ptr;
  65 }
  66
  67 void *
  68 dlopen(const char *path, int mode)
  69 {
  70         HMODULE         h;
  71         int                     prevmode;
  72
  73         /* Disable popup error messages when loading DLLs */
  74         prevmode = SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOOPENFILEERRORBOX);
  75         h = LoadLibrary(path);
  76         SetErrorMode(prevmode);
  77
  78         if (!h)
  79         {
  80                 set_dl_error();
  81                 return NULL;
  82         }
  83         last_dyn_error[0] = 0;
  84         return (void *) h;
  85 }