tests: mgmt: mcumgr: Disable erroneous clang warning

tests/subsys/mgmt/mcumgr/settings_mgmt/src/main.c:69:22: error: variable
'test_response_read_data_start' is not needed and will not be emitted
[-Werror,-Wunneeded-internal-declaration]
static const uint8_t test_response_read_data_start[5] = {
                     ^
tests/subsys/mgmt/mcumgr/settings_mgmt/src/main.c:73:22: error: variable
'test_response_read_data_end' is not needed and will not be emitted
[-Werror,-Wunneeded-internal-declaration]
static const uint8_t test_response_read_data_end[1] = {
                     ^

Signed-off-by: Tom Hughes <[email protected]>

Author: thughes

include/zephyr/toolchain/llvm.h

@@ -31,6 +31,7 @@
 #include <zephyr/toolchain/gcc.h>
 
 #define TOOLCHAIN_WARNING_SIZEOF_ARRAY_DECAY "-Wsizeof-array-decay"
+#define TOOLCHAIN_WARNING_UNNEEDED_INTERNAL_DECLARATION "-Wunneeded-internal-declaration"
 
 #define TOOLCHAIN_DISABLE_CLANG_WARNING(warning) _TOOLCHAIN_DISABLE_WARNING(clang, warning)
 #define TOOLCHAIN_ENABLE_CLANG_WARNING(warning)  _TOOLCHAIN_ENABLE_WARNING(clang, warning)

tests/subsys/mgmt/mcumgr/settings_mgmt/src/main.c

@@ -66,13 +66,16 @@ static const uint8_t test_response_error_data[8] = {
 	0xbf, 0x62, 0x72, 0x63, 0x19, 0x01, 0x00, 0xff
 };
 
+/* Disable erroneous clang warning: https://github.com/llvm/llvm-project/issues/25458. */
+TOOLCHAIN_DISABLE_CLANG_WARNING(TOOLCHAIN_WARNING_UNNEEDED_INTERNAL_DECLARATION)
 static const uint8_t test_response_read_data_start[5] = {
 	0xbf, 0x63, 0x76, 0x61, 0x6c
 };
 
 static const uint8_t test_response_read_data_end[1] = {
 	0xff
 };
+TOOLCHAIN_ENABLE_CLANG_WARNING(TOOLCHAIN_WARNING_UNNEEDED_INTERNAL_DECLARATION)
 
 static void cleanup_test(void *p)
 {