Try to fix build failed in Ubuntu 14.04

generic/tgdbm.c

@@ -43,37 +43,30 @@
 
 static char rcsid[] = "$Id: tgdbm.c,v 1.5 2005/04/14 14:13:01 svogel Exp $";
 
-#if defined(WIN32)
-# if defined(_MSC_VER)
-# define EXPORT(a,b) __declspec(dllexport) a b
+// Sync to tcl.h
+#if (defined(__WIN32__) && (defined(_MSC_VER) || (__BORLANDC__ >= 0x0550) || defined(__LCC__) || defined(__WATCOMC__) || (defined(__GNUC__) && defined(__declspec))))
+# define HAVE_DECLSPEC 1
+# ifdef STATIC_BUILD
+# define DLLIMPORT
+# define DLLEXPORT
+# ifdef _DLL
+# define CRTIMPORT __declspec(dllimport)
+# else
+# define CRTIMPORT
+# endif
 # else
-# if defined(__BORLANDC__)
-# define EXPORT(a,b) a _export b
-# else
-# define EXPORT(a,b) a b
-# endif
+# define DLLIMPORT __declspec(dllimport)
+# define DLLEXPORT __declspec(dllexport)
+# define CRTIMPORT __declspec(dllimport)
 # endif
 #else
-# define EXPORT(a,b) a b
-#endif
-
-#ifdef STATIC_BUILD
-# define DLLIMPORT
-# define DLLEXPORT
-#else
-#ifdef WIN32
-# define DLLEXPORT __declspec(dllexport) // dll-creation
-# define DLLIMPORT __declspec(dllimport)
-#else
-# define DLLIMPORT // static lib
-# define DLLEXPORT
-#endif
-#endif
-
-#ifdef USE_DLL
-# define IMEXPORT DLLIMPORT
-#else
-# define IMEXPORT DLLEXPORT
+# define DLLIMPORT
+# if defined(__GNUC__) && __GNUC__ > 3
+# define DLLEXPORT __attribute__ ((visibility("default")))
+# else
+# define DLLEXPORT
+# endif
+# define CRTIMPORT
 #endif
 
 /*
@@ -104,8 +97,9 @@ extern "C" {
 #endif
 
 /* These external variables are needed by tgdbm */
-extern const char* gdbm_version;
-extern gdbm_error gdbm_errno;
+// Define in gdbm.h, disable it
+//extern const char* gdbm_version;
+//extern gdbm_error gdbm_errno;
 
 #define TGDBM_VERSION "0.5"
 
@@ -1550,8 +1544,7 @@ Gdbm_Cmd(cd_gdbm, interp, argc, argv)
  * #define DllEntryPoint DllMain 
  *----------------------------------------------------------------------
  */
-EXPORT(int, Tgdbm_Init)(interp)
- Tcl_Interp* interp;
+EXTERN int Tgdbm_Init(Tcl_Interp *interp)
 {
  int i;
  char sErrnum[5], sErrMsg[128];