-extern void heapCensus( void );
-extern nat initHeapProfiling( void );
-extern void endHeapProfiling( void );
-extern void LDV_recordDead( StgClosure *c, nat size );
-extern rtsBool strMatchesSelector( char* str, char* sel );
+#pragma GCC visibility push(hidden)
+
+void heapCensus (void);
+nat initHeapProfiling (void);
+void endHeapProfiling (void);
+void LDV_recordDead (StgClosure *c, nat size);
+rtsBool strMatchesSelector (char* str, char* sel);
+
+#pragma GCC visibility pop