When compiling the current code on GCC 4.8.3, the following warnings appear:

warning: format '%zu' expects argument of type 'size_t', but argument 2 has type 'long unsigned int' [-Wformat=]

There were many mails about such warnings on different architectures. This patch limits itself to the nios2 architecture.

The problem is that for the size_t (%zu, %zd, ...) arguments of printf GCC does not verify the type match to size_t type. It verifies the type match to the compiler-defined __SIZE_TYPE__ type. Thus, if size_t is defined different from __SIZE_TYPE__ - warnings inevitably appear.

There is a comment by Thomas Chou to the (rejected) patch: http://patchwork.ozlabs.org/patch/272102/ which explains that the older GCC toolchains (gcc-3.4.6 and gcc-4.1.2) expect size_t to be "unsigned long" and the newer expect it to be "unsigned int". Thus, no matter how we define size_t - either way warnings appear when using some GCC version.

By rejecting that patch, a choice was made to prefer older GCC versions and leave the warnings when building with the newer toolchains. Personally, I disagree with this choice...

In any case, this patch proposes a way to fix the warnings for any GCC version. Just define size_t using the __SIZE_TYPE__ compiler-defined type and the type verification will pass.

I tested that this fixes the warning on GCC 4.8.3. I don't have an older toolchain to test with, but __SIZE_TYPE__ was definitely defined in GCC 3.4.6, so it should work there too.

Signed-off-by: Vasili Galka vvv444@gmail.com Cc: Thomas Chou thomas@wytron.com.tw --- arch/nios2/include/asm/posix_types.h | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/arch/nios2/include/asm/posix_types.h b/arch/nios2/include/asm/posix_types.h index 6733640..6b6c39b 100644 --- a/arch/nios2/include/asm/posix_types.h +++ b/arch/nios2/include/asm/posix_types.h @@ -16,7 +16,11 @@ typedef int __kernel_pid_t; typedef unsigned short __kernel_ipc_pid_t; typedef unsigned short __kernel_uid_t; typedef unsigned short __kernel_gid_t; +#ifdef __GNUC__ +typedef __SIZE_TYPE__ __kernel_size_t; +#else typedef unsigned long __kernel_size_t; +#endif typedef long __kernel_ssize_t; typedef int __kernel_ptrdiff_t; typedef long __kernel_time_t;