r195676 - Make the integrated assembler the default for cygwin/mingw too.

[Bill Wendling]

Okay I reverted r195823.

-bw

On Nov 30, 2013, at 5:28 PM, NAKAMURA Takumi <geek4civic at gmail.com> wrote:

> Rafael,
> I see. I don't object to switch -integrated-as by default. It's good
> and what I'd like to do.
> To give an error to -no-integrated-as, could you file bugzilla for
> this issue, "incompatibilities to gnu as"?
> (llc is already affected.)
> 
> Bill,
> At least, release_34/r195823 (master/r195798) should be reverted.
> 
> 2013/12/1 Rafael Espíndola <rafael.espindola at gmail.com>:
>> On 30 November 2013 08:10, NAKAMURA Takumi <geek4civic at gmail.com> wrote:
>>> Rafael,
>>> 
>>> Since llvm's r195798, clang -no-integrated-as has been broken, at
>>> least on cygming gnu as.
>>> Would you like to hide incompatibility to gnu as?
>>> 
>>> FYI, release_34 has been broken due to lack of this, r195676, on
>>> cygwin selfhosting.
>>> http://bb.pgr.jp/builders/clang-3stage-cygwin/builds/1348
>> 
>> How come 34 has r195798 but not r195676?
>> 
>> The short answer is that gnu as has the fundamental limitation of not
>> supporting two sections with the same name on COFF (it does support it
>> on ELF). Defining the same sections as gcc is pretty much impossible
>> given that it can't agree with itself in different optimization levels
>> (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59236).
>> 
>> If we really need to support gnu as on COFF, we can do some arbitrary
>> section name uniquing behind a flag. The best course I think is to not
>> have r195798 on 3.4 and produce an error for -no-integrated-as on
>> trunk (as we already do for -win32 triples).
>> 
>> Cheers,
>> Rafael