Having them in the header files disables direct mode when compiling
ccache itself.
const int HASH_SOURCE_CODE_FOUND_TIME = (1 << 2);
const int HASH_SOURCE_CODE_FOUND_TIMESTAMP = (1 << 3);
-// Search for the strings "__DATE__", "__TIME__" and "__TIMESTAMP__" in `str`.
+// Search for the strings "DATE", "TIME" and "TIMESTAMP" with two surrounding
+// underscores in `str`.
//
// Returns a bitmask with HASH_SOURCE_CODE_FOUND_DATE,
// HASH_SOURCE_CODE_FOUND_TIME and HASH_SOURCE_CODE_FOUND_TIMESTAMP set