Re: [Tinycc-devel] mob broken; how to develop with mob and community

[Roy Tam]

Hello,

2014-05-04 2:44 GMT+08:00 Michael Matz <address@hidden>:
> Hello,
>
> okay, are the last commits to mob from jiang meant as joke or vandalism?
>
> * 32bit code generation is hosed already in the testsuite, * gawk doesn't
> work anymore even for x86_64,
> * arm codegen is broken already in the testsuite (adding an internal
>   compiler error)
> * they contain ugly white-space changes making review exceedingly hard
> * despite the unnecessarily hard review I think there are numerous
>   problems in the actual implementation:
>   + the new parse_number uses inexact floating point directly (e.g. 1.0L/b
>     when b==10 isn't exactly representable, cumulating errors while
>     parsing)
>   + There's a new subtype VT_VLS meaning VLA plus STRUCT, which makes no
>     sense at all (VLA is VL _array_)
>   + TREG_MEM (also new) doesn't follow convention for type flags, and
>     seems like a layering violation
>   + It reverts a cleanup by Thomas (eda2c756edc4dca004ba217) without
>     discussion
>   + It renames libtcc1.a to libcrt.a, thereby trading a sensibly
>     tcc-specific name for something tcc-specific with something generic
>     (what if gcc had libcrt as well?)
>   + It increases VT_STRUCT_SHIFT to 20, breaking bitfields larger than 31
>     bits (we needs 12 bits to encode bitfield position and size, so the
>     maximum bit shift can be 19
>   + It changes gv2() so that VT_CMP/VT_JMP results aren't special-cased
>     anymore, without obvious compensation in all its users to avoid the
>     errors that the comment specifically mentioned
>   + It implements some strange non-standard preprocessor extension
>     push_macro/pop_macro (as pragmas) without discussion; it enlargens
>     some heavily used internal data structures for this.
>   + It adds some "fix x86-64 vla" commit, without testcase showing what's
>     actually broken, and for that shuffles the internal code generations
>     in large and unobvious ways (and removes the correct calls to alloca()
>     on x86-64 PE)
>
> And that's just what I saw on a cursory read of the commits.  Due to the
> white-space changes the more intricate parts are terrible to review and I've
> skipped them.
>
> When I wrote above "without discussion", then this was just for the most
> controversial parts.  It's true for all the patches.  I've seen no messages
> at all from jiang to this mailing list.  No discussion about implementation
> approaches, no discussions about bugs, no nothing.  The commit messages are
> mostly non-informative as well.
>
> All in all I think this approach is pretty unacceptable, but others here
> might differ.  If the patch series were a smaller then the problems in it
> could reasonably be fixed after the fact by others.  But as it stands we now
> have something in which every single one of the 22 topmost patches (ignoring
> the white-space fixup patch from grischka) has issues.
>
> If it were just my project I'd be tempted to revert the whole mob state to
> be before your (jiangs) patches, and expect you to work with the community
> to fix what you actually wanted to fix or improve.  (From the patch series I
> gather that one thing you wanted to fix was parameter passing on stack when
> memcpy is needed).  It the very minimum you have to subscribe to this
> mailing list (that's even listed in the mob rules), and of course also take
> part in discussions.  You also have to _review_ your patches before
> commiting (you would have seen the useless white-space changes) and write
> meaningful commit messages.
>
> Any opinions from others?
>

IMO I'd urge jiang to create fork in github instead.

>
> Ciao,
> Michael.
>
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