src/port/win32dlopen.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * win32dlopen.c
   4  *        dynamic loader for Windows
   5  *
   6  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        src/port/win32dlopen.c
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15
  16 #include "c.h"
  17
  18 static char last_dyn_error[512];
  19
  20 static void
  21 set_dl_error(void)
  22 {
  23         DWORD           err = GetLastError();
  24
  25         if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS |
  26                                           FORMAT_MESSAGE_FROM_SYSTEM,
  27                                           NULL,
  28                                           err,
  29                                           MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT),
  30                                           last_dyn_error,
  31                                           sizeof(last_dyn_error) - 1,
  32                                           NULL) == 0)
  33         {
  34                 snprintf(last_dyn_error, sizeof(last_dyn_error) - 1,
  35                                  "unknown error %lu", err);
  36         }
  37 }
  38
  39 char *
  40 dlerror(void)
  41 {
  42         if (last_dyn_error[0])
  43                 return last_dyn_error;
  44         else
  45                 return NULL;
  46 }
  47
  48 int
  49 dlclose(void *handle)
  50 {
  51         if (!FreeLibrary((HMODULE) handle))
  52         {
  53                 set_dl_error();
  54                 return 1;
  55         }
  56         last_dyn_error[0] = 0;
  57         return 0;
  58 }
  59
  60 void *
  61 dlsym(void *handle, const char *symbol)
  62 {
  63         void       *ptr;
  64
  65         ptr = GetProcAddress((HMODULE) handle, symbol);
  66         if (!ptr)
  67         {
  68                 set_dl_error();
  69                 return NULL;
  70         }
  71         last_dyn_error[0] = 0;
  72         return ptr;
  73 }
  74
  75 void *
  76 dlopen(const char *file, int mode)
  77 {
  78         HMODULE         h;
  79         int                     prevmode;
  80
  81         /* Disable popup error messages when loading DLLs */
  82         prevmode = SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOOPENFILEERRORBOX);
  83         h = LoadLibrary(file);
  84         SetErrorMode(prevmode);
  85
  86         if (!h)
  87         {
  88                 set_dl_error();
  89                 return NULL;
  90         }
  91         last_dyn_error[0] = 0;
  92         return (void *) h;
  93 }