Update CMakeLists.txt for fixes warning -Wundef

Signed-off-by: Yonggang Luo <[email protected]>

Author: lygstate

CMakeLists.txt

@@ -84,7 +84,7 @@ add_library("printf::printf" ALIAS printf)
 set(GENERATED_INCLUDE_DIR "${CMAKE_CURRENT_BINARY_DIR}/include")
 configure_file("printf_config.h.in" "${GENERATED_INCLUDE_DIR}/printf_config.h" @ONLY)
 target_sources(printf PRIVATE src/printf/printf.c "${GENERATED_INCLUDE_DIR}/printf_config.h" src/printf/printf.h)
-target_compile_definitions(printf PRIVATE PRINTF_INCLUDE_CONFIG_H)
+target_compile_definitions(printf PRIVATE PRINTF_INCLUDE_CONFIG_H=1)
 target_include_directories(printf PRIVATE "$<BUILD_INTERFACE:${GENERATED_INCLUDE_DIR}>")
 
 if (BUILD_SHARED_LIBS)
@@ -121,6 +121,7 @@ elseif (CMAKE_C_COMPILER_ID STREQUAL "GNU" OR
 		-ansi
 		-Wno-long-long
 		-Werror=declaration-after-statement
+		-Werror=undef
 	)
 	set_target_properties(printf PROPERTIES C_STANDARD 90)
 	set_target_properties(printf PROPERTIES C_STANDARD_REQUIRED ON)

test/CMakeLists.txt

@@ -25,7 +25,9 @@ foreach(tgt ${test_targets})
 	endif()
 endforeach()
 
+target_compile_definitions(autotest PRIVATE PRINTF_INCLUDE_CONFIG_H=0)
 add_executable(aliasing "aliasing.c")
+target_compile_definitions(aliasing PRIVATE PRINTF_INCLUDE_CONFIG_H=0)
 set_target_properties(
 	${tgt}
 	PROPERTIES
@@ -88,7 +90,7 @@ if (TARGET test_suite)
 	# These two lines are necessary, since the test suite does not actually use the
 	# compiled library - it includes the library's source .c file; and that means we
 	# need to include the generated config.h file.
-	target_compile_definitions(test_suite PRIVATE PRINTF_INCLUDE_CONFIG_H)
+	target_compile_definitions(test_suite PRIVATE PRINTF_INCLUDE_CONFIG_H=1)
 	target_include_directories(
 		test_suite
 		PRIVATE