Windows breakage -- again

[Johan Tibell]

Great. Thanks all for your help!

On Sat, Jul 19, 2014 at 2:04 AM, Austin Seipp <austin at well-typed.com> wrote:
> Thanks Niklas, this is now committed.
>
> On Fri, Jul 18, 2014 at 9:21 AM, Niklas Larsson <metaniklas at gmail.com> wrote:
>> I posted a working and tested patch last night. Please feel free to commit
>> it, I haven't the rights to do it.
>>
>> Niklas
>> ________________________________
>> Från: Simon Peyton Jones
>> Skickat: ‎2014-‎07-‎18 15:55
>> Till: Niklas Larsson; Johan Tibell
>> Kopia: ghc-devs at haskell.org
>> Ämne: RE: Windows breakage -- again
>>
>> Thank you all for pursuing this.  I gather that you know what is going on,
>> so no further info needed from me.  Yell if it is otherwise.
>>
>>
>>
>> Meanwhile, is the fix imminent, or should we revert Johan’s patch?
>>
>>
>>
>> Simon
>>
>>
>>
>> From: Niklas Larsson [mailto:metaniklas at gmail.com]
>> Sent: 16 July 2014 19:58
>> To: Johan Tibell; Simon Peyton Jones
>> Cc: ghc-devs at haskell.org
>> Subject: Re: Windows breakage -- again
>>
>>
>>
>> I get the same failure when I try to build HEAD. Turns out the error occurs
>> on the 32-bit Windows build, and my successful build was a 64-bit build. My
>> 64-bit build still succeeds.
>>
>> Also, gcc is 4.5.2 on 32-bit, not 4.6.3 as on 64-bit.
>>
>> Niklas
>>
>>
>>
>>
>>
>> 2014-07-16 14:48 GMT+02:00 Niklas Larsson <metaniklas at gmail.com>:
>>
>> I have built ghc on windows after that was added with no issue.
>>
>> I can take a look this evening and  see how HEAD works for me.
>>
>> The standard gcc in the tarballs is 4.6.3, which is getting long in the
>> tooth, there is an issue on trac to upgrade it.
>>
>> -- Niklas
>>
>> ________________________________
>>
>> Från: Johan Tibell
>> Skickat: ‎2014-‎07-‎16 09:57
>> Till: Simon Peyton Jones
>> Kopia: ghc-devs at haskell.org
>> Ämne: Re: Windows breakage -- again
>>
>> You can rollback the commit (git revert
>> 4ee4ab01c1d97845aecb7707ad2f9a80933e7a49) and push that to the repo if you
>> wish. I will try to re-add the primop again after I figure out what's wrong.
>>
>>
>>
>> On Wed, Jul 16, 2014 at 9:37 AM, Johan Tibell <johan.tibell at gmail.com>
>> wrote:
>>
>> I added some primops about a month ago
>> (4ee4ab01c1d97845aecb7707ad2f9a80933e7a49) that call __sync_fetch_and_add, a
>> gcc/llvm builtin. I'm a bit surprised to see this error. The GCC manual [1]
>> says:
>>
>>
>>
>>> " Not all operations are supported by all target processors. If a
>>> particular operation cannot be implemented on the target processor, a
>>> warning will be generated and a call an external function will be generated.
>>> The external function will carry the same name as the builtin, with an
>>> additional suffix `_n' where n is the size of the data type."
>>
>>
>>
>> I'm a bit surprised by this error for two reasons:
>>
>>
>>
>>  * A call to that symbol should only be generated if the CPU doesn't support
>> the atomic instructions. What CPU model does Windows report that you have?
>>
>>
>>
>>  * gcc should define such a symbol. For me the following test program
>> compiles:
>>
>>
>>
>> #include <stdint.h>
>>
>>
>>
>> uint8_t test(uint8_t* ptr, uint8_t val) {
>>
>>   return __sync_fetch_and_add_1(ptr, val);
>>
>> }
>>
>>
>>
>> int main(void) {
>>
>>   uint8_t n;
>>
>>   return test(&n, 1);
>>
>> }
>>
>>
>>
>> Does that compile for you? Which version of GCC do we end up using on
>> Windows?
>>
>>
>>
>> The reported symbol (___sync_fetch_and_add_1) has three leading underscores,
>> that looks weird. Can you compile just libraries/ghc-prim/cbits/atomic.c and
>> see if it's indeed GCC that generates a reference to that symbol?
>>
>>
>>
>> 1. http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gcc/Atomic-Builtins.html
>>
>>
>>
>> On Wed, Jul 16, 2014 at 12:29 AM, Simon Peyton Jones <simonpj at microsoft.com>
>> wrote:
>>
>> Aargh!  The Windows build has broken – again.  I can’t build GHC on my
>> laptop any more.
>>
>>
>> [Hela det ursprungliga meddelandet tas inte med.]
>>
>> _______________________________________________
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>> ghc-devs at haskell.org
>> http://www.haskell.org/mailman/listinfo/ghc-devs
>>
>
>
>
> --
> Regards,
>
> Austin Seipp, Haskell Consultant
> Well-Typed LLP, http://www.well-typed.com/