clang/gcc: Add build option FREECAD_WARN_ERROR to force to make warnings into errors

src/Mod/Measure/App/CMakeLists.txt

@@ -71,6 +71,9 @@ endif(FREECAD_USE_PCH)
 
 add_library(Measure SHARED ${Measure_SRCS})
 target_link_libraries(Measure ${Measure_LIBS})
+if (FREECAD_WARN_ERROR)
+    target_compile_warn_error(Measure)
+endif()
 
 #if(MSVC)
 #    set_target_properties(Measure PROPERTIES SUFFIX ".pyd")

src/Mod/Measure/Gui/CMakeLists.txt

@@ -86,6 +86,9 @@ SET(MeasureGuiIcon_SVG
 
 add_library(MeasureGui SHARED ${MeasureGui_SRCS} ${MeasureGuiIcon_SVG})
 target_link_libraries(MeasureGui ${MeasureGui_LIBS})
+if (FREECAD_WARN_ERROR)
+    target_compile_warn_error(MeasureGui)
+endif()
 
 SET_BIN_DIR(MeasureGui MeasureGui /Mod/Measure)
 SET_PYTHON_PREFIX_SUFFIX(MeasureGui)