src/port/dlopen.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * dlopen.c
   4  *        dynamic loader for platforms without dlopen()
   5  *
   6  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        src/port/dlopen.c
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15
  16 #include "c.h"
  17
  18 #if defined(__hpux)
  19
  20 /* System includes */
  21 #include <a.out.h>
  22 #include <dl.h>
  23
  24 void *
  25 dlopen(const char *file, int mode)
  26 {
  27         int                     flags = 0;
  28
  29         if (mode & RTLD_NOW)
  30                 flags |= BIND_IMMEDIATE;
  31 #ifdef NOT_USED
  32         if (mode & RTLD_LAZY)
  33                 flags |= BIND_DEFERRED;
  34 #endif
  35
  36         return shl_load(file, flags | BIND_VERBOSE, 0L);
  37 }
  38
  39 void *
  40 dlsym(void *handle, const char *symbol)
  41 {
  42         void       *value;
  43
  44         if (shl_findsym((shl_t *) & handle, symbol, TYPE_PROCEDURE, &value) == -1)
  45                 return NULL;
  46         return value;
  47 }
  48
  49 int
  50 dlclose(void *handle)
  51 {
  52         return shl_unload((shl_t) handle);
  53 }
  54
  55 char *
  56 dlerror(void)
  57 {
  58         static char errmsg[] = "shl_load failed";
  59
  60         if (errno)
  61                 return strerror(errno);
  62
  63         return errmsg;
  64 }
  65
  66 #elif defined(WIN32)
  67
  68 static char last_dyn_error[512];
  69
  70 static void
  71 set_dl_error(void)
  72 {
  73         DWORD           err = GetLastError();
  74
  75         if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS |
  76                                           FORMAT_MESSAGE_FROM_SYSTEM,
  77                                           NULL,
  78                                           err,
  79                                           MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT),
  80                                           last_dyn_error,
  81                                           sizeof(last_dyn_error) - 1,
  82                                           NULL) == 0)
  83         {
  84                 snprintf(last_dyn_error, sizeof(last_dyn_error) - 1,
  85                                  "unknown error %lu", err);
  86         }
  87 }
  88
  89 char *
  90 dlerror(void)
  91 {
  92         if (last_dyn_error[0])
  93                 return last_dyn_error;
  94         else
  95                 return NULL;
  96 }
  97
  98 int
  99 dlclose(void *handle)
 100 {
 101         if (!FreeLibrary((HMODULE) handle))
 102         {
 103                 set_dl_error();
 104                 return 1;
 105         }
 106         last_dyn_error[0] = 0;
 107         return 0;
 108 }
 109
 110 void *
 111 dlsym(void *handle, const char *symbol)
 112 {
 113         void       *ptr;
 114
 115         ptr = GetProcAddress((HMODULE) handle, symbol);
 116         if (!ptr)
 117         {
 118                 set_dl_error();
 119                 return NULL;
 120         }
 121         last_dyn_error[0] = 0;
 122         return ptr;
 123 }
 124
 125 void *
 126 dlopen(const char *file, int mode)
 127 {
 128         HMODULE         h;
 129         int                     prevmode;
 130
 131         /* Disable popup error messages when loading DLLs */
 132         prevmode = SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOOPENFILEERRORBOX);
 133         h = LoadLibrary(file);
 134         SetErrorMode(prevmode);
 135
 136         if (!h)
 137         {
 138                 set_dl_error();
 139                 return NULL;
 140         }
 141         last_dyn_error[0] = 0;
 142         return (void *) h;
 143 }
 144
 145 #endif