KWIML: Suppress printf/scanf format warnings in test

KWIML defines format string macros matching the fixed-sized types.  This
test checks that they behave as expected and that the arguments match
the *sizes* expected by the format strings.

test/CMakeLists.txt

@@ -18,6 +18,13 @@ set_property(DIRECTORY
   "KWIML_HEADER(%)=<${KWIML}/%>"
   )
 
+# Suppress printf/scanf format warnings; we test if the sizes match.
+foreach(lang C CXX)
+  if(KWIML_LANGUAGE_${lang} AND "${CMAKE_${lang}_COMPILER_ID}" STREQUAL GNU)
+    set(CMAKE_${lang}_FLAGS "${CMAKE_${lang}_FLAGS} -Wno-format")
+  endif()
+endforeach()
+
 if(KWIML_LANGUAGE_C)
   set(test_srcs test.c)
 else()