[LLVMdev] Section specialization & COFF.

[r4start]

On 07/11/12 10:49, r4start wrote:
> On 03/11/12 01:37, Michael Spencer wrote:
>> On Wed, Oct 31, 2012 at 9:41 AM, r4start <r4start at gmail.com> wrote:
>>> On 24/10/12 17:03, r4start wrote:
>>>> On 23/10/12 01:30, Michael Spencer wrote:
>>>>> On Mon, Oct 22, 2012 at 7:53 AM, r4start <r4start at gmail.com> wrote:
>>>>>> On 20/10/12 03:15, Michael Spencer wrote:
>>>>>>> On Fri, Oct 19, 2012 at 2:55 AM, r4start <r4start at gmail.com> wrote:
>>>>>>>> Hi all.
>>>>>>>>
>>>>>>>> While compiling next code
>>>>>>>> @A = weak unnamed_addr constant { i32, i32, i32 } { i32 0, i32 
>>>>>>>> 0, i32
>>>>>>>> 0
>>>>>>>> },
>>>>>>>> section ".data"
>>>>>>>> was discovered that llc ignores weak linkage if we emit it in COFF
>>>>>>>> object.
>>>>>>>> Attached patch solves this problem, please review.
>>>>>>>>
>>>>>>>> I found some similar tests in test/Objects/Inputs. Should I do
>>>>>>>> something
>>>>>>>> like trivial.ll checking or there is a better way
>>>>>>>> to check patch behaviour?
>>>>>>>>
>>>>>>>>     - Dmitry Sokolov.
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> LLVM Developers mailing list
>>>>>>>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>>>>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>>>>>>>
>>>>>>> test/Object is not the right place for the test. It should 
>>>>>>> probably go
>>>>>>> in test/MC/COFF as a .ll file, although technically it's codegen...
>>>>>>>
>>>>>>> Also, I'm pretty sure this is wrong for MinGW. What do msvc and
>>>>>>> mingw-gcc produce for c code that generates this?
>>>>>>>
>>>>>>> - Michael Spencer
>>>>>> For this c code(see attachments) cl, mingw and clang produce 
>>>>>> different
>>>>>> coff's(was used dumpbin with option /ALL):
>>>>>> 1) Cl generate separate COMDAT section with linkage selection 
>>>>>> "pick any"
>>>>>> 2) Mingw place this value to regular section and place special 
>>>>>> auxilary
>>>>>> record to symbol table
>>>>>> 3) Clang without patch just ignore weakness of this value and 
>>>>>> place it
>>>>>> to
>>>>>> regular section.
>>>>>>      But for weak values without explicit section specification 
>>>>>> it use
>>>>>> cl-like
>>>>>> way. i.e. generate
>>>>>>      separate COMDAT section with a little difference in naming 
>>>>>> (unique
>>>>>> suffix
>>>>>> after $)
>>>>>> 4) With this patch clang will generate correct COMDAT section for 
>>>>>> values
>>>>>> with explicit section specification.
>>>>>>
>>>>>> The problem is in backend. When we have explicit section 
>>>>>> specification
>>>>>> linkage type is ignored.
>>>>> Looks fine with a test in CodeGen.
>>>>>
>>>>> - Michael Spencer
>>>> Was added test.
>>>> Please review.
>>>> Patch was made by Dmitry Puzirev.
>>> Ping?
>> lgtm.
>>
>> - Michael Spencer
> Can anybody commit patch.
> I don`t have commit rights.
Ping? Can anybody commit this patch?