[svn-r20323] Correct depends of test for CPP examples and add clear test

bring r20322 from trunk

c++/examples/CMakeLists.txt

@@ -24,9 +24,30 @@ FOREACH (example ${examples})
   ADD_EXECUTABLE (cpp_ex_${example} ${HDF5_CPP_EXAMPLES_SOURCE_DIR}/${example}.cpp)
   TARGET_NAMING (cpp_ex_${example} ${LIB_TYPE})
   TARGET_LINK_LIBRARIES (cpp_ex_${example} ${HDF5_CPP_LIB_TARGET} ${HDF5_LIB_TARGET})
-
-  IF (BUILD_TESTING)
-    ADD_TEST (NAME cpp_ex_${example} COMMAND $<TARGET_FILE:cpp_ex_${example}>)
-  ENDIF (BUILD_TESTING)
-
 ENDFOREACH (example ${examples})
+
+IF (BUILD_TESTING)
+  # Remove any output file left over from previous test run
+  ADD_TEST (
+      NAME cpp_ex-clear-objects
+      COMMAND    ${CMAKE_COMMAND}
+          -E remove 
+          Group.h5
+          SDS.h5
+          SDScompound.h5
+          SDSextendible.h5
+          Select.h5
+  )
+  IF (NOT "${last_test}" STREQUAL "")
+    SET_TESTS_PROPERTIES (cpp_ex-clear-objects PROPERTIES DEPENDS ${last_test})
+  ENDIF (NOT "${last_test}" STREQUAL "")
+  SET (last_test "cpp_ex-clear-objects")
+
+  FOREACH (example ${examples})
+    ADD_TEST (NAME cpp_ex_${example} COMMAND $<TARGET_FILE:cpp_ex_${example}>)
+    IF (NOT "${last_test}" STREQUAL "")
+      SET_TESTS_PROPERTIES (cpp_ex_${example} PROPERTIES DEPENDS ${last_test})
+    ENDIF (NOT "${last_test}" STREQUAL "")
+    SET (last_test "cpp_ex_${example}")
+  ENDFOREACH (example ${examples})
+ENDIF (BUILD_TESTING)