Warning if type mismatch

I have one file in which I use "int16_t x", when I declared it in other file, by mistake I have declared "extern int8_t x". i.e int8_t is used instead of int16_t. But compiler do not generate warning...
Warning if type mismatch

I have one file in which I use "int16_t x", when I declared it in other file, by mistake I have declared "extern int8_t x". i.e int8_t is used instead of int16_t. But compiler do not generate warning...
why get error "Type mismatch (arg. no. 1) (ptrs to signed/unsigned)"?

------------------------------------------- #define uchar unsigned char uchar xdata lcd_show_buf[20]; uchar num; num = 2; sprintf(lcd_show_buf, "%4d", num); ----------------------------...
why get error "Type mismatch (arg. no. 1) (ptrs to signed/unsigned)"?

------------------------------------------- #define uchar unsigned char uchar xdata lcd_show_buf[20]; uchar num; num = 2; sprintf(lcd_show_buf, "%4d", num); ----------------------------...
External Funtion Type

This works: extern char Fn1( char, char ); extern char Fn2( char, char ); extern char Fn3( char, char ); This causes a lot of linker errors. typedef char FnT( char, char ); extern FnT Fn1,Fn2,Fn3;...