Am 20.09.2010 21:18, schrieb Blue Swirl:
On Mon, Sep 13, 2010 at 8:02 PM, Stefan Weil<w...@mail.berlios.de> wrote:Since version 4.4.x, gcc supports additional format attributes. __attribute__ ((format (gnu_printf, 1, 2))) should be used instead of __attribute__ ((format (printf, 1, 2)) because QEMU always uses standard format strings (even with mingw32).For older compilers, we simply define gnu_printf = printf, so they work with the new format attribute, too. Signed-off-by: Stefan Weil<w...@mail.berlios.de> --- configure | 11 +++++++++++ 1 files changed, 11 insertions(+), 0 deletions(-) diff --git a/configure b/configure index 4061cb7..1300879 100755 --- a/configure +++ b/configure @@ -148,6 +148,17 @@ for flag in $gcc_flags; do fi done +# Check gnu_printf (supported by gcc>= 4.4.x). +cat> $TMPC<< EOF +static void test(const char *format, ...) + __attribute__ ((format (gnu_printf, 1, 2))); +static void test(const char *format, ...) {} +int main(void) { test("\n"); return 0; } +EOF +if ! compile_prog "-Werror" ""; then + QEMU_CFLAGS="-Dgnu_printf=printf $QEMU_CFLAGS"This could cause problems, for example if system headers declared a function called gnu_printf. I'd introduce CONFIG_GCC_FMT_ATTR_GNU_PRINTF and adjust GCC_FMT_ATTR definition based on that.
Thanks for your review. I'll send a new patch which goes into the direction which you suggested. Instead of defining a new macro CONFIG_GCC_FMT_ATTR_GNU_PRINTF, my new patch checks the gcc version (gnu_printf was introduced with gcc 4.4). Like this, no changes to file configure are needed. Regards Stefan
