merge file and configuration for test_c and test_cpp

test/CMakeLists.txt

@@ -5,8 +5,13 @@ option(CHECK_USING_CLANG "check if target is compiled using Clang" OFF)
 
 add_executable(hello_world hello_world.cpp)
 
-add_executable(test_c EXCLUDE_FROM_ALL test.c)
-target_compile_definitions(test_c PRIVATE $<$<BOOL:${CHECK_USING_CLANG}>:CHECK_USING_CLANG>)
-
-add_executable(test_cpp EXCLUDE_FROM_ALL test.cpp)
-target_compile_definitions(test_cpp PRIVATE $<$<BOOL:${CHECK_USING_CLANG}>:CHECK_USING_CLANG>)
+list(APPEND LANGS c cpp)
+foreach(LANG ${LANGS})
+  configure_file(test.in ${CMAKE_CURRENT_BINARY_DIR}/test.${LANG})
+  add_executable(test_${LANG} EXCLUDE_FROM_ALL ${CMAKE_CURRENT_BINARY_DIR}/test.${LANG})
+  target_compile_definitions(
+    test_${LANG} PRIVATE
+    $<$<STREQUAL:"${LANG}","c">:IS_C>
+    $<$<BOOL:${CHECK_USING_CLANG}>:CHECK_USING_CLANG>
+  )
+endforeach()

test/test.c

@@ -1,10 +0,0 @@
-#include <stdio.h>
-
-int main() {
-#if defined(CHECK_USING_CLANG) && !defined(__clang__)
-  printf("compiler is not clang\n");
-  return 1;
-#endif
-  printf("all ok\n");
-  return 0;
-}

test/test.cpp

@@ -1,10 +0,0 @@
-#include <iostream>
-
-int main() {
-#if defined(CHECK_USING_CLANG) && !defined(__clang__)
-  std::cout << "compiler is not clang" << std::endl;
-  return 1;
-#endif
-  std::cout << "all ok" << std::endl;
-  return 0;
-}

test/test.in

@@ -0,0 +1,16 @@
+#ifdef IS_C
+#include <stdio.h>
+#define PRINT(STR) printf(STR); printf("\n")
+#else
+#include <iostream>
+#define PRINT(STR) std::cout << STR << std::endl
+#endif
+
+int main() {
+#if defined(CHECK_USING_CLANG) && !defined(__clang__)
+  PRINT("compiler is not clang");
+  return 1;
+#endif
+  PRINT("all ok");
+  return 0;
+}