At the end of the day, it all comes down to passing format string as variable - the code below also does not produce error: const char *str = "Last printf: %B\n"; printf(str, 2); Can someone explain why this happens?
Because with only a few exceptions (e.g., -Wuninitialized, -Wstrict-aliasing, or -Wstrict-overflow), warnings are implemented in an early stage of the translation process before the compiler has done the sort of program analysis or optimization necessary to "see" variable values. It only considers the values of literals and constants, as in: const char str[] = "Last printf: %B\n"; printf (str, 2); // warning It doesn't do any sort of indirection so this won't cause a warning either: const char* const str = "Last printf: %B\n"; printf (str, 2); // no warning Martin
