format mismatch warnings

[dl8dtl]

/home/joerg/src/avrdude/src/dfu.c:398:5: warning: format specifies type 'unsigned short' but the argument has type 'int' [-Wformat]
    ((unsigned short) dfu->dev_desc.bcdDevice >> 8) & 0xFF,
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/joerg/src/avrdude/src/avrdude.h:59:97: note: expanded from macro 'msg_info'
#define msg_info(...)       avrdude_message2(stderr, __LINE__, __FILE__, __func__, 0, MSG_INFO, __VA_ARGS__)
                                                                                                ^~~~~~~~~~~
/home/joerg/src/avrdude/src/dfu.c:399:5: warning: format specifies type 'unsigned short' but the argument has type 'int' [-Wformat]
    ((unsigned short) dfu->dev_desc.bcdDevice >> 4) & 0xF,
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/joerg/src/avrdude/src/avrdude.h:59:97: note: expanded from macro 'msg_info'
#define msg_info(...)       avrdude_message2(stderr, __LINE__, __FILE__, __func__, 0, MSG_INFO, __VA_ARGS__)
                                                                                                ^~~~~~~~~~~
/home/joerg/src/avrdude/src/dfu.c:400:5: warning: format specifies type 'unsigned short' but the argument has type 'int' [-Wformat]
    ((unsigned short) dfu->dev_desc.bcdDevice >> 0) & 0xF);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/joerg/src/avrdude/src/avrdude.h:59:97: note: expanded from macro 'msg_info'
#define msg_info(...)       avrdude_message2(stderr, __LINE__, __FILE__, __func__, 0, MSG_INFO, __VA_ARGS__)
…
/home/joerg/src/avrdude/src/flip2.c:559:5: warning: format specifies type 'unsigned short' but the argument has type 'int' [-Wformat]
    ((unsigned short) flip2->boot_ver >> 4) & 0xF,
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/joerg/src/avrdude/src/avrdude.h:59:97: note: expanded from macro 'msg_info'
#define msg_info(...)       avrdude_message2(stderr, __LINE__, __FILE__, __func__, 0, MSG_INFO, __VA_ARGS__)
                                                                                                ^~~~~~~~~~~
/home/joerg/src/avrdude/src/flip2.c:560:5: warning: format specifies type 'unsigned short' but the argument has type 'int' [-Wformat]
    ((unsigned short) flip2->boot_ver >> 0) & 0xF);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/joerg/src/avrdude/src/avrdude.h:59:97: note: expanded from macro 'msg_info'
#define msg_info(...)       avrdude_message2(stderr, __LINE__, __FILE__, __func__, 0, MSG_INFO, __VA_ARGS__)
                                                                                                ^~~~~~~~~~~
/home/joerg/src/avrdude/src/flip2.c:781:70: warning: format specifies type 'unsigned short' but the argument has type 'int' [-Wformat]
      pmsg_error("address out of range [0x%04hX,0x%04hX]\n", offset, offset+size-1);
                                                  ~~~~~              ^~~~~~~~~~~~~
                                                  %04X
/home/joerg/src/avrdude/src/avrdude.h:67:176: note: expanded from macro 'pmsg_error'
#define pmsg_error(...)     avrdude_message2(stderr, __LINE__, __FILE__, __func__, MSG2_PROGNAME|MSG2_FUNCTION|MSG2_FILELINE|MSG2_TYPE|MSG2_FLUSH|MSG2_LEFT_MARGIN, MSG_ERROR, __VA_ARGS__)
                                                                                                                                                                               ^~~~~~~~~~~
/home/joerg/src/avrdude/src/flip2.c:839:70: warning: format specifies type 'unsigned short' but the argument has type 'int' [-Wformat]
      pmsg_error("address out of range [0x%04hX,0x%04hX]\n", offset, offset+size-1);
                                                  ~~~~~              ^~~~~~~~~~~~~
                                                  %04X
/home/joerg/src/avrdude/src/avrdude.h:67:176: note: expanded from macro 'pmsg_error'
#define pmsg_error(...)     avrdude_message2(stderr, __LINE__, __FILE__, __func__, MSG2_PROGNAME|MSG2_FUNCTION|MSG2_FILELINE|MSG2_TYPE|MSG2_FLUSH|MSG2_LEFT_MARGIN, MSG_ERROR, __VA_ARGS__)
                                                                                                                                                                               ^~~~~~~~~~~

There would at least be an (unsigned short) typecast missing.

Anyway, I wonder what's the point of forcing all that into unsigned short, rather than keeping it simply unsigned, and remove all the h format modificators?

[stefanrueger]

The format is wrong, it should not say h, as C cannot pass a short to a function without first promoting to int (likewise unsigned). However, the printf implementation should also know that C passes an int, so should silently ignore the format (which it probably does).

[dl8dtl]

I am no longer so sure about that statement (and even reading the C standard doesn't make it better :).

I'd say, let's drop the h modifiers, and change all (unsigned short) typecasts when passing arguments (in the lines before those complained about above) into (unsigned) typecasts.

Do you want me to prepare a PR?

[stefanrueger]

The format is wrong, it should not say h

The utility of %h[dxu] is to convert the int/unsigned argument (automatically promoted!) to short or unsigned short before printing. In most of above cases the h isn't needed as the argument already is pretty small. The following

#include <stdio.h>
int main() {
  printf("%04hd\n", 32768*17);
}

prints -32768 owing to the argument 0x88000 being converted to short 0x8000 and then, being a negative short printed so.