[LLVMdev] [lld] LLD's software architecture (update)

[Bas van den Berg]

I've run a new scan of LLD's architecture and it appears to be getting
cleaner!

There are still some upward dependencies however:
- core depends on Reader and Writer
- passes depend on Reader and Writer
- ReaderWriter/PECOFF/ReaderCOFF.cpp depends on Driver.h

The updated architecture can be seen here:
http://www.c2lang.org/docs/lld_architecture_20140710.png


On Tue, Jun 3, 2014 at 3:07 AM, Rui Ueyama <ruiu at google.com> wrote:

> I will create a patch to move the files and send it for review.
>
>
> On Mon, Jun 2, 2014 at 1:05 PM, Michael Spencer <bigcheesegs at gmail.com>
> wrote:
>
>> On Mon, Jun 2, 2014 at 12:49 AM, Rui Ueyama <ruiu at google.com> wrote:
>> > I agree to move these files to Core. Any objections?
>>
>> None here.
>>
>> - Michael Spencer
>>
>> >
>> > On Mon, Jun 2, 2014 at 12:44 AM, Bas van den Berg
>> > <b.van.den.berg.nl at gmail.com> wrote:
>> >>
>> >> The inverted dependency of Core to ReaderWriter via Simple.h was
>> already
>> >> present.
>> >> My idea was to fix the problem before it gets bigger.
>> >> My proposal would be to move Simple.h and Alias.h to Core. Similar to
>> >> UndefinedAtom.h etc.
>> >> It would be even nicer to make the naming consistent as well, since
>> there
>> >> already is
>> >> UndefinedAtom.h
>> >> SharedLibaryAtom.h
>> >> etc
>> >>
>> >> Maybe:
>> >> SimpleAtom.h
>> >> AliasAtom.h
>> >>
>> >> Moving the file to core fixes the dependencies.
>> >>
>> >>
>> >>
>> >>
>> >> On Mon, Jun 2, 2014 at 9:25 AM, Rui Ueyama <ruiu at google.com> wrote:
>> >>>
>> >>> On Mon, Jun 2, 2014 at 12:01 AM, Bas van den Berg
>> >>> <b.van.den.berg.nl at gmail.com> wrote:
>> >>>>
>> >>>> Hi,
>> >>>>
>> >>>> I've been following the changes in LLD's software architecture.
>> >>>> Recently a new file was added: Alias.h
>> >>>> In this file, the curret Atom set is extended with an AliasAtom.
>> >>>> While the change seems innocent enough, it has some nasty
>> >>>> potential. Simple.h and Alias.h are placed in the ReaderWriter
>> >>>> component. This is the 2nd component in the layering:
>> >>>> Driver
>> >>>> ReaderWriter
>> >>>> Passes
>> >>>> Core
>> >>>>
>> >>>> The problem is that Core depends on these files. So in my opinion,
>> >>>> they belong to that Component. The greater impact here is that
>> >>>> once core starts depending on ReaderWriter, architecture Erosion
>> >>>> will happen. This would obviously not be a good thing, since the
>> >>>> current design is fresh and clean.
>> >>>
>> >>>
>> >>> Core's dependency to Simple.h was there before the addition of
>> Alias.h,
>> >>> so it's not new. And I don't feel like it's that bad as you might be
>> >>> feeling. Do you have any suggestion to get rid of it? Just moving the
>> file
>> >>> to Core?
>> >>>
>> >>>> I would love to supply patches, but am having issues getting
>> >>>> lld to build under Ubuntu 12.04. (but that's another story ;) ).
>> >>>>
>> >>>> I've posted the updated architecture view here:
>> >>>> http://www.c2lang.org/docs/lld_architecture_20140602.png
>> >>>>
>> >>>>
>> >>>> _______________________________________________
>> >>>> LLVM Developers mailing list
>> >>>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> >>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>> >>>>
>> >>>
>> >>
>> >
>> >
>> > _______________________________________________
>> > LLVM Developers mailing list
>> > LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>> >
>>
>
>
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