Hi Masahiro,
On 22 December 2014 at 03:16, Masahiro Yamada yamada.m@jp.panasonic.com wrote:
CONFIG_USE_STDINT was introduced to use compiler-provided types for fixed-width variables. This must be consistent everywhere to avoid warnings/errors including printf() and friends.
Assume the code below
uint32_t foo;
printf("foo= %x\n", foo);
If <stdint.h> is included, uint32_t is defined by the compiler. The code above only works on compilers that define "uint32_t" as "unsigned int". Actually there exist compilers that define "uint32_t" as "unsigned long".
Going forward, to print out fixed-width variables, we always have to use PRIxN like this
uint32_t foo;
printf("foo= " PRIx32 "\n", foo);
Notice,
- Typedefs ( uint32_t, int32_t etc.) are provided by <stdint.h>
- Printf formats ( PRIx32, PRId32 etc.) are provided by <inttypes.h>
Also notice, it makes sense only when <stdint.h> and <inttypes.h> are provided by the same compiler. ^^^^^^^^^^^^^^^^^^
Commit 4166ecb24 (Add some standard headers external code might need) added hard-coded include/inttypes.h. It provides hard-coded PRIx32 "x", but it does not make sense. Some compiler's <stdint.h> define "uint32_t" as "unsigned long" and expect the format string "lx" to print out "uint32_t" variable.
This commit:
Adds scripts/gcc-have-stdint.sh to check if the compiler is providing both <stdint.h> and <inttypes.h>
Modifies config.mk to error-out if CONFIG_USE_STDINT is enabled, but <stdint.h> or <inttyps.h> is missing
Modifies the top Makefile to delete "-nostdinc" option and allow to include compiler-provided <inttypes.h>
Remove hard-coded include/inttypes.h
This patch looks good to me except that I don't understand why you are removing inttypes.h? Where will the PRI defines come from? Or is it because you are fixing things such that the defines are not needed anymore?
Signed-off-by: Masahiro Yamada yamada.m@jp.panasonic.com Cc: Gabe Black gabeblack@chromium.org Cc: Simon Glass sjg@chromium.org Cc: Bill Richardson wfrichar@google.com Cc: Tom Rini trini@ti.com
Makefile | 2 +- config.mk | 12 ++ include/inttypes.h | 287 --------------------------------------------- scripts/gcc-have-stdint.sh | 21 ++++ 4 files changed, 34 insertions(+), 288 deletions(-) delete mode 100644 include/inttypes.h create mode 100755 scripts/gcc-have-stdint.sh
[snip]
Regards, Simon