Re: [Bulk] Re: [PATCH 4/10] compiler-gcc{3,4}.h: Use GCC_VERSION macro

Daniel Santos
2012-09-29T00:31:56Z

On 09/28/2012 07:20 PM, Josh Triplett wrote:
> On Fri, Sep 28, 2012 at 06:20:05PM -0500, Daniel Santos wrote:
>> --- a/include/linux/compiler-gcc4.h
>> +++ b/include/linux/compiler-gcc4.h
>> @@ -13,11 +13,11 @@
>> #define __must_check __attribute__((warn_unused_result))
>> #define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
>>
>> -#if __GNUC_MINOR__ > 0
>> +#if GCC_VERSION >= 40102
>> # define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
>> #endif
> You've changed the semantics of this one; if literally translated, this
> should have become #if GCC_VERSION >= 40100. If you intended to change
> that, could you please document why? And in any case, could you make
> that semantic change in a separate commit from the switch to
> GCC_VERSION?
hmm, it looks like somebody commented out the #error that would normally
prevent that test from ever occurring on 4.1.0 or 4.1.1.
When I had written this patch, it wasn't commented out and I had assumed
that it was obvious from the context.
> /* GCC 4.1.[01] miscompiles __weak */
> #ifdef __KERNEL__
> -# if __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1
> +# if GCC_VERSION >= 40100 && GCC_VERSION <= 40101
> //# error Your version of gcc miscompiles the __weak directive
> # endif
> #endif
> @@ -13,11 +13,11 @@
> #define __must_check __attribute__((warn_unused_result))
> #define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
>
> -#if __GNUC_MINOR__ > 0
> +#if GCC_VERSION >= 40102
> # define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
> #endif
I would say that commenting this out is bad if __weak is miscompiled.
If we don't want to break the build, should we at least be defining
__weak to something else?

Daniel