Remove obsolete darwin dynloader code

not needed since macOS 10.3 (2003)

Author: petere

src/backend/port/dynloader/darwin.c

@@ -1,24 +1,15 @@
 /*
  * Dynamic loading support for macOS (Darwin)
  *
- * If dlopen() is available (Darwin 10.3 and later), we just use it.
- * Otherwise we emulate it with the older, now deprecated, NSLinkModule API.
- *
  * src/backend/port/dynloader/darwin.c
  */
 #include "postgres.h"
 
-#ifdef HAVE_DLOPEN
 #include <dlfcn.h>
-#else
-#include <mach-o/dyld.h>
-#endif
 
 #include "dynloader.h"
 
 
-#ifdef HAVE_DLOPEN
-
 void *
 pg_dlopen(const char *filename)
 {
@@ -34,7 +25,6 @@ pg_dlclose(void *handle)
 PGFunction
 pg_dlsym(void *handle, const char *funcname)
 {
-/* Do not prepend an underscore: see dlopen(3) */
 return dlsym(handle, funcname);
 }
 
@@ -43,96 +33,3 @@ pg_dlerror(void)
 {
 return dlerror();
 }
-#else/* !HAVE_DLOPEN */
-
-/*
- * These routines were taken from the Apache source, but were made
- * available with a PostgreSQL-compatible license. Kudos Wilfredo
- * Sánchez <wsanchez@apple.com>.
- */
-
-static NSObjectFileImageReturnCode cofiff_result = NSObjectFileImageFailure;
-
-void *
-pg_dlopen(const char *filename)
-{
-NSObjectFileImage image;
-
-cofiff_result = NSCreateObjectFileImageFromFile(filename, &image);
-if (cofiff_result != NSObjectFileImageSuccess)
-return NULL;
-return NSLinkModule(image, filename,
-NSLINKMODULE_OPTION_BINDNOW |
-NSLINKMODULE_OPTION_RETURN_ON_ERROR);
-}
-
-void
-pg_dlclose(void *handle)
-{
-NSUnLinkModule(handle, NSUNLINKMODULE_OPTION_NONE);
-}
-
-PGFunction
-pg_dlsym(void *handle, const char *funcname)
-{
-NSSymbol symbol;
-char *symname = (char *) malloc(strlen(funcname) + 2);
-
-if (!symname)
-return NULL;
-
-sprintf(symname, "_%s", funcname);
-if (NSIsSymbolNameDefined(symname))
-{
-symbol = NSLookupAndBindSymbol(symname);
-
-free(symname);
-return (PGFunction) NSAddressOfSymbol(symbol);
-}
-else
-{
-free(symname);
-return NULL;
-}
-}
-
-char *
-pg_dlerror(void)
-{
-NSLinkEditErrors c;
-interrorNumber;
-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;
-}
-
-#endif/* HAVE_DLOPEN */