Fix support for GCC hidden visibility.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit 402204029e)

src/tqca.cpp

@@ -19,6 +19,10 @@
  *
  */
 
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
 #include "tqca.h"
 #include "tqcaprovider.h"
 

src/tqca.h

@@ -29,16 +29,14 @@
 #include <tqptrlist.h>
 #include <tqobject.h>
 
-#ifdef Q_OS_WIN32
-#  ifndef TQCA_STATIC
-#    ifdef TQCA_MAKEDLL
-#      define TQCA_EXPORT __declspec(dllexport)
-#    else
-#      define TQCA_EXPORT __declspec(dllimport)
-#    endif
-#  endif
-#endif
-#ifndef TQCA_EXPORT
+#if defined(__KDE_HAVE_GCC_VISIBILITY) || defined(G_HAVE_GCC_VISIBILITY)
+#define TQCA_NO_EXPORT __attribute__ ((visibility("hidden")))
+#define TQCA_EXPORT __attribute__ ((visibility("default")))
+#elif defined(_WIN32)
+#define TQCA_NO_EXPORT
+#define TQCA_EXPORT __declspec(dllexport)
+#else
+#define TQCA_NO_EXPORT
 #define TQCA_EXPORT
 #endif