-extern void checkHeap ( bdescr *bd );
-extern void checkHeapChunk ( StgPtr start, StgPtr end );
-extern void checkLargeObjects ( bdescr *bd );
-extern void checkTSO ( StgTSO* tso );
-extern void checkGlobalTSOList ( rtsBool checkTSOs );
-extern void checkStaticObjects ( StgClosure* static_objects );
-extern void checkStackChunk ( StgPtr sp, StgPtr stack_end );
-extern StgOffset checkStackFrame ( StgPtr sp );
-extern StgOffset checkClosure ( StgClosure* p );
+void checkHeap ( bdescr *bd );
+void checkHeapChunk ( StgPtr start, StgPtr end );
+void checkLargeObjects ( bdescr *bd );
+void checkTSO ( StgTSO* tso );
+void checkGlobalTSOList ( rtsBool checkTSOs );
+void checkStaticObjects ( StgClosure* static_objects );
+void checkStackChunk ( StgPtr sp, StgPtr stack_end );
+StgOffset checkStackFrame ( StgPtr sp );
+StgOffset checkClosure ( StgClosure* p );