Add code to provide useful dynamic-linking error messages on OS X.

diff --git a/src/backend/port/dynloader/darwin.c b/src/backend/port/dynloader/darwin.c
index 5d1aa757ce08a44f0d6d168d04452b99406cd67d..8810308a14710162d9d3fbf3ba3688953507b58b 100644 (file)
--- a/src/backend/port/dynloader/darwin.c
+++ b/src/backend/port/dynloader/darwin.c
@@ -3,31 +3,35 @@
  * available with a PostgreSQL-compatible license.     Kudos Wilfredo
  * Sánchez <wsanchez@apple.com>.
  *
- * $Header: /cvsroot/pgsql/src/backend/port/dynloader/darwin.c,v 1.6 2002/10/01 05:06:44 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/port/dynloader/darwin.c,v 1.7 2003/04/13 01:19:06 tgl Exp $
  */
-
 #include "postgres.h"
+
 #include <mach-o/dyld.h>
+
 #include "dynloader.h"
 
+
+static NSObjectFileImageReturnCode cofiff_result = NSObjectFileImageFailure;
+
+
 void *
 pg_dlopen(char *filename)
 {
        NSObjectFileImage image;
 
-       if (NSCreateObjectFileImageFromFile(filename, &image) !=
-               NSObjectFileImageSuccess)
+       cofiff_result = NSCreateObjectFileImageFromFile(filename, &image);
+       if (cofiff_result != NSObjectFileImageSuccess)
                return NULL;
        return NSLinkModule(image, filename,
-                           NSLINKMODULE_OPTION_BINDNOW |
-                           NSLINKMODULE_OPTION_RETURN_ON_ERROR);
+                                               NSLINKMODULE_OPTION_BINDNOW |
+                                               NSLINKMODULE_OPTION_RETURN_ON_ERROR);
 }
 
 void
 pg_dlclose(void *handle)
 {
        NSUnLinkModule(handle, FALSE);
-       return;
 }
 
 PGFunction
@@ -53,5 +57,38 @@ pg_dlsym(void *handle, char *funcname)
 char *
 pg_dlerror(void)
 {
-       return "no error message available";
+       NSLinkEditErrors c;
+       int errorNumber;
+       const char *fileName;
+       const char *errorString = NULL;
+
+       switch (cofiff_result)
+       {
+               case NSObjectFileImageSuccess:
+                       /* must have failed in NSLinkModule */
+                       NSLinkEditError(&c, &errorNumber, &fileName, &errorString);
+                       if (errorString == NULL || *errorString == '\0')
+                               errorString = "unknown link-edit failure";
+                       break;
+               case NSObjectFileImageFailure:
+                       errorString = "failed to open object file";
+                       break;
+               case NSObjectFileImageInappropriateFile:
+                       errorString = "inappropriate object file";
+                       break;
+               case NSObjectFileImageArch:
+                       errorString = "object file is for wrong architecture";
+                       break;
+               case NSObjectFileImageFormat:
+                       errorString = "object file has wrong format";
+                       break;
+               case NSObjectFileImageAccess:
+                       errorString = "insufficient permissions for object file";
+                       break;
+               default:
+                       errorString = "unknown failure to open object file";
+                       break;
+       }
+
+       return (char *) errorString;
 }