printf/inttypes.h warning

[Joel Sherrill]

Hi

Top posting because I now have results from testing making
the proposed change to gcc's newlib-stdint.h to use the
same logic as newlib-glibc.h

All the targets that built are now warning free.  At the moment,
avr, m32c, and nios2 won't build.

The gcc patch is attached. I thought we should discuss it here
before posting it to gcc.

Besides, I can't get to gcc's bugzilla this morning for some reason.

--joel

On 12/16/2014 09:53 AM, Joel Sherrill wrote:
>
> On December 16, 2014 7:44:39 AM PST, Joseph Myers<joseph@codesourcery.com>  wrote:
>> On Tue, 16 Dec 2014, Corinna Vinschen wrote:
>>
>>>> It is GCC. gcc/config/newlib-stdint.h where GCC defines the types.
>>> Ok, I didn't know there's newlib-specific stuff in GCC.  I'm just
>>> not sure in how far this is newlib's fault.  The usage of
>> __INTPTR_TYPE__
>>> looks right to me.  The gcc/config/newlib-stdint.h file seems to be
>>> outdated???
>> newlib-stdint.h is meant to replicate the logic used by all versions of
>>
>> newlib to select these types, including versions predating the addition
>> of
>> macros such as __INTPTR_TYPE__.
>>
>> * The choices of these types are meant to be constant over time.
>>
>> * GCC needs to know them (without reference to the newlib headers when
>> GCC
>> is built) for such purposes as Fortran C bindings.
>>
>> * newlib stdint.h as of 2008/9 was used as the source of truth about
>> these
>> types when writing newlib-stdint.h.
>>
>> * When newlib uses macros such as __INTPTR_TYPE__ it's indirectly using
>>
>> GCC's newlib-stdint.h as a source of truth - but this should never
>> change
>> the choice of types relative to what would be used with older GCC or
>> non-GCC compilers.
> I.don't disagree with any of that but I wouldn't necessarily treat the old newlib stdint.h as 100% correct.  I don't believe that most embedded targets ever gave much thought to this issue and it is propagating into inttypes.h. Other than cygwin, I doubt binary comparability is even an issue as most build from source..
>
> For sure this uses different logic than glic-stdint.h and that results in some targets using int for pointer types while others use long.
>
> We can make it consistent in newlib-stdint.h or we have to add target architecture specific conditional logic inttypes.h to make the printf PRIxxx match the type.
>
> It is inconsistent now and has to be fixed on one side or the other.
>
> I always lean to simple and consistent which makes me want to fix newlib-stdint.h.
>
> --joel

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