coalesce.c should be compiled only when WITH_COALESCING is ON.

src/CMakeLists.txt

@@ -30,7 +30,6 @@ endif (WITH_STATIC_LIB)
 
 set(dmmlib_SRCS
   block_header.c
-  coalesce.c
   custom_free.c
   custom_malloc.c
   dmm_adaptor.c
@@ -47,6 +46,13 @@ if (HAVE_LOCKS)
   )
 endif (HAVE_LOCKS)
 
+if (WITH_COALESCING)
+  set(dmmlib_SRCS
+    ${dmmlib_SRCS}
+    coalesce.c
+  )
+endif (WITH_COALESCING)
+
 include_directories(
   ${DMMLIB_PUBLIC_INCLUDE_DIRS}
   ${DMMLIB_PRIVATE_INCLUDE_DIRS}