granicus.if.org Git - postgresql/blob - src/backend/port/dynloader/darwin.c

   1 /*
   2  * Dynamic loading support for Darwin
   3  *
   4  * If dlopen() is available (Darwin 10.3 and later), we just use it.
   5  * Otherwise we emulate it with the older, now deprecated, NSLinkModule API.
   6  *
   7  * $PostgreSQL: pgsql/src/backend/port/dynloader/darwin.c,v 1.12 2007/11/15 21:14:37 momjian Exp $
   8  */
   9 #include "postgres.h"
  10
  11 #ifdef HAVE_DLOPEN
  12 #include <dlfcn.h>
  13 #else
  14 #include <mach-o/dyld.h>
  15 #endif
  16
  17 #include "dynloader.h"
  18
  19
  20 #ifdef HAVE_DLOPEN
  21
  22 void *
  23 pg_dlopen(char *filename)
  24 {
  25         return dlopen(filename, RTLD_NOW | RTLD_GLOBAL);
  26 }
  27
  28 void
  29 pg_dlclose(void *handle)
  30 {
  31         dlclose(handle);
  32 }
  33
  34 PGFunction
  35 pg_dlsym(void *handle, char *funcname)
  36 {
  37         /* Do not prepend an underscore: see dlopen(3) */
  38         return dlsym(handle, funcname);
  39 }
  40
  41 char *
  42 pg_dlerror(void)
  43 {
  44         return dlerror();
  45 }
  46 #else                                                   /* !HAVE_DLOPEN */
  47
  48 /*
  49  * These routines were taken from the Apache source, but were made
  50  * available with a PostgreSQL-compatible license.      Kudos Wilfredo
  51  * Sánchez <wsanchez@apple.com>.
  52  */
  53
  54 static NSObjectFileImageReturnCode cofiff_result = NSObjectFileImageFailure;
  55
  56 void *
  57 pg_dlopen(char *filename)
  58 {
  59         NSObjectFileImage image;
  60
  61         cofiff_result = NSCreateObjectFileImageFromFile(filename, &image);
  62         if (cofiff_result != NSObjectFileImageSuccess)
  63                 return NULL;
  64         return NSLinkModule(image, filename,
  65                                                 NSLINKMODULE_OPTION_BINDNOW |
  66                                                 NSLINKMODULE_OPTION_RETURN_ON_ERROR);
  67 }
  68
  69 void
  70 pg_dlclose(void *handle)
  71 {
  72         NSUnLinkModule(handle, FALSE);
  73 }
  74
  75 PGFunction
  76 pg_dlsym(void *handle, char *funcname)
  77 {
  78         NSSymbol        symbol;
  79         char       *symname = (char *) malloc(strlen(funcname) + 2);
  80
  81         sprintf(symname, "_%s", funcname);
  82         if (NSIsSymbolNameDefined(symname))
  83         {
  84                 symbol = NSLookupAndBindSymbol(symname);
  85                 free(symname);
  86                 return (PGFunction) NSAddressOfSymbol(symbol);
  87         }
  88         else
  89         {
  90                 free(symname);
  91                 return NULL;
  92         }
  93 }
  94
  95 char *
  96 pg_dlerror(void)
  97 {
  98         NSLinkEditErrors c;
  99         int                     errorNumber;
 100         const char *fileName;
 101         const char *errorString = NULL;
 102
 103         switch (cofiff_result)
 104         {
 105                 case NSObjectFileImageSuccess:
 106                         /* must have failed in NSLinkModule */
 107                         NSLinkEditError(&c, &errorNumber, &fileName, &errorString);
 108                         if (errorString == NULL || *errorString == '\0')
 109                                 errorString = "unknown link-edit failure";
 110                         break;
 111                 case NSObjectFileImageFailure:
 112                         errorString = "failed to open object file";
 113                         break;
 114                 case NSObjectFileImageInappropriateFile:
 115                         errorString = "inappropriate object file";
 116                         break;
 117                 case NSObjectFileImageArch:
 118                         errorString = "object file is for wrong architecture";
 119                         break;
 120                 case NSObjectFileImageFormat:
 121                         errorString = "object file has wrong format";
 122                         break;
 123                 case NSObjectFileImageAccess:
 124                         errorString = "insufficient permissions for object file";
 125                         break;
 126                 default:
 127                         errorString = "unknown failure to open object file";
 128                         break;
 129         }
 130
 131         return (char *) errorString;
 132 }
 133
 134 #endif   /* HAVE_DLOPEN */