Add extern prototype for GC_collection_in_progress

diff --git a/gc_dlopen.c b/gc_dlopen.c
index 51659d1e8236fccb3ca44a394eccb6014f716698..2f9644efdbe1378b93a83be358e9615b4276644e 100644 (file)
--- a/gc_dlopen.c
+++ b/gc_dlopen.c
@@ -37,6 +37,8 @@
 #   undef dlopen
 # endif
 
+  extern GC_bool GC_collection_in_progress();
+
   /* Make sure we're not in the middle of a collection, and make       */
   /* sure we don't start any.  Returns previous value of GC_dont_gc.   */
   /* This is invoked prior to a dlopen call to avoid synchronization   */