llvm dev - May 2017 - Email list just for front end developers?

On Sat, 6 May 2017 13:46:18 -0700 Sanjoy Das via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> > I'm not sure that will work well, because people won't usually
> > wait a week to get their questions before moving on. If you're
> > actively working full time on a project, you probably want
> > answers in much less time.  
> 
> Sure s/week/day/ then. :)  You're also welcome to be more active on
> the existing IRC channel.
I've tried being active on (and asking questions on) the IRC channel.
There doesn't seem to be much of a culture of answering questions
there either, though. :(
> > But again, that said, if people really think that this is the
> > right place for such things and not a new list, that can probably
> > be given a good faith effort. My perception was that it probably
> > wouldn't work well because this list is de facto for something
> > else, but I'm willing to try if that's a strong consensus.  
> 
> Let me put it this way -- I'm pretty sure if you take it on yourself
> to answer beginner questions on llvm-dev promptly, nobody will
> *complain*.  In fact, you're going to make some folks happy. :)
Sure, but who will answer mine? Part of the reason I asked about
this was selfish, as I'd like access to other people in the same
situation as me who might know answers. (I don't think the people here
now will want to answer more questions, and many of my questions
doubtless border on inanely stupid but for the fact that it is hard
to find answers in the docs.)

That said, I'm willing to give it a try, as an experiment. How long
should we attempt it for? If that's reasonably agreed to, I'll
personally give it a good faith effort myself during the period. (I'm
not sure I will be able to help with more than a fraction of the
questions, being very new at this myself, but I'll do my best.)

If we are to try this for real, we also might want to make some sort
of effort to encourage people to ask more questions here, or it is
likely that the current habit of not asking them will persist.

Perry
-- 
Perry E. Metzger		perry at piermont.com

Hi Perry,

On Sat, May 6, 2017 at 2:55 PM, Perry E. Metzger <perry at piermont.com>
wrote:
>> Let me put it this way -- I'm pretty sure if you take it on
yourself
>> to answer beginner questions on llvm-dev promptly, nobody will
>> *complain*.  In fact, you're going to make some folks happy. :)
>
> Sure, but who will answer mine? Part of the reason I asked about
> this was selfish, as I'd like access to other people in the same
> situation as me who might know answers. (I don't think the people here
> now will want to answer more questions, and many of my questions
> doubtless border on inanely stupid but for the fact that it is hard
> to find answers in the docs.)
I don't see how people who don't have time to answer on llvm-dev will
find time to answer on some other mailing list.
> That said, I'm willing to give it a try, as an experiment. How long
> should we attempt it for? If that's reasonably agreed to, I'll
Depends on how much time you have -- that's the limiting resource here.

However, I liked your idea of maintaining a wiki-like thing.  Both
http://llvm.org/docs/Frontend/PerformanceTips.html and
http://llvm.org/docs/tutorial/ will be good additions there.
> personally give it a good faith effort myself during the period. (I'm
> not sure I will be able to help with more than a fraction of the
> questions, being very new at this myself, but I'll do my best.)
Thanks!
-- Sanjoy

On Sat, 6 May 2017 21:38:50 -0700 Sanjoy Das
<sanjoy at playingwithpointers.com> wrote:
> Hi Perry,
> 
> On Sat, May 6, 2017 at 2:55 PM, Perry E. Metzger
> <perry at piermont.com> wrote:
> >> Let me put it this way -- I'm pretty sure if you take it on
> >> yourself to answer beginner questions on llvm-dev promptly,
> >> nobody will *complain*.  In fact, you're going to make some
> >> folks happy. :)
> >
> > Sure, but who will answer mine? Part of the reason I asked about
> > this was selfish, as I'd like access to other people in the same
> > situation as me who might know answers. (I don't think the people
> > here now will want to answer more questions, and many of my
> > questions doubtless border on inanely stupid but for the fact
> > that it is hard to find answers in the docs.)
>
> I don't see how people who don't have time to answer on llvm-dev
> will find time to answer on some other mailing list.
My belief was they would be different populations. That is why there
would be a separate list. The other list would attract mostly front
end devs. I would expect front end devs would be both more interested
in a list that discusses mostly things they care about (including IR
changes they need to be aware of) and more interested in mutual
assistance.

But never mind, it seems that I'm the only person who likes that idea,
so we're ignoring that possibility for the moment.
> > That said, I'm willing to give it a try, as an experiment. How
> > long should we attempt it for? If that's reasonably agreed to,
> > I'll
>
> Depends on how much time you have -- that's the limiting resource
> here.
By time I meant the question of how long one tries a strategy before
deciding to look for new strategies. :) Given that few questions about
front end things arrive on the -dev list, trying to help answering
them, for the moment, will only require that I attend more closely to
the postings, and that other people make a bit of an effort to answer
"dumb questions" as well.

Hopefully that will simply work. My skepticism comes from the feeling
that if it was really going to work, it would have already, but
there's no reason not to give it a good faith try.

On the wider issue:

LLVM has been transformative. There are now a lot more people
experimenting with compiling languages than ever before (including
me!) because LLVM removes a lot of the pain from constructing
everything past the IR.

However, until I started working with it personally, I didn't
understand how much work it was to learn how to use it, and much of
that work is because there is a very big gap between the programmers
guide + the tutorial (which makes it all look like you can learn the
whole thing in an afternoon) and what you actually need to figure out
to get things done. Much of what you need you have to puzzle out
painstakingly on your own, trying to make sense of the doxygen docs
and reading code, because there's less written down than one would
hope. Even the IR language reference, which is seemingly complete at
first glance, has some big gaps in it.

Given good enough resources, though, even more people could be using
LLVM to create compilers, which would be a great thing. And,
selfishly, given better resources, my own work would be easier. :)
Thus my overall interest.
> However, I liked your idea of maintaining a wiki-like thing.  Both
> http://llvm.org/docs/Frontend/PerformanceTips.html and
> http://llvm.org/docs/tutorial/ will be good additions there.
Parts of the programmer's manual
http://llvm.org/docs/ProgrammersManual.html are also essential, though
for a front end developer, especially one using the C API, not
everything is something you want to know, and it isn't initially
obvious when you need to read closely.

Anyway, given that you would prefer for it not to be an actual wiki,
what would be lower barrier to entry and Wiki-ish?

(A big issue with the current workflow, I think, is that for outsiders
submitting documentation updates the process is very heavyweight. Even
the use of svn vs. git increases the amount of work for casual users.
It's just not worth it as it stands for someone to say "hey, please
fix just this one sentence", especially if you've never contributed to
LLVM before. However, often even single sentence edits improve
comprehension. Having a low barrier for small fixes is one of the
reasons Wikipedia grew so fast. Of course, it is also the reason that
policing Wikipedia takes huge effort, so there's a tradeoff.)


Perry
-- 
Perry E. Metzger		perry at piermont.com

2nd try to sent this email. ^^
---

@Perry:
Thank you so much for reading and mentioning my beginner post here in 
the mailing list. Let us work together: Additional mailing list, wiki, 
usefull Q&A, tutorials - everything which helps newbies would be fine 
for me to work on. :)

@All:
I am the author of the post Perry mentioned and I would love to see help 
on my newbie questions, an "API usage" wiki or a Q&A with
beginner´s
questions on the usage of the LLVM API. Before I posted, I tried to read 
as much as possible in blog articles and tutorials about the LLVM API, 
but most of my questions were still open (I also read the C++, Rust, 
Java, Lua, Python stuff, because C examples are very rare). My last hope 
was the mailling list here in end of march 2017. Since my post, I paused 
my project, because I had no clue how to continue. I planned until March 
a bloody beginner tutorial on how to use LLVM API with C (variables, 
arrays, assignments, loops, if-then-else, structs, functions, 
parameters, heap /stack allocation, use of std functions, classes, 
exeptions, etc.).

The tutorials I found were often too small (just a simple int function 
which delivers 42 and had no parameters or real body/block stuff), over 
ten years old and totally deprecated or detailed, but with too less 
focus on the LLVM API part (complex parser in C++, different approaches 
for scanner in C++ and at the end just a few lines of LLVM API for the 
IR generation).

Please see the beginner problems from a LLVM API perspective:
It is very, very, very, very easy to find information in the internet 
about planning and creating a new programming language (lexing, 
scanning, error reporting, etc.), that is not the problem here. You 
hardly find no good explanation on how to use the LLVM API for 
generating the final IR. If you can not find infos about this last step, 
continuing with an own programming language does not make any sense, 
because writing an own compiler backend instead of using the LLVM API is 
nonsense, because we have this awesome LLVM, we just had no clue how to 
use its API.

Best regards,
Thomas

Am 07.05.2017 06:38 schrieb Sanjoy Das via llvm-dev:
> Hi Perry,
> 
> On Sat, May 6, 2017 at 2:55 PM, Perry E. Metzger <perry at
piermont.com>
> wrote:
>>> Let me put it this way -- I'm pretty sure if you take it on
yourself
>>> to answer beginner questions on llvm-dev promptly, nobody will
>>> *complain*.  In fact, you're going to make some folks happy. :)
>> 
>> Sure, but who will answer mine? Part of the reason I asked about
>> this was selfish, as I'd like access to other people in the same
>> situation as me who might know answers. (I don't think the people
here
>> now will want to answer more questions, and many of my questions
>> doubtless border on inanely stupid but for the fact that it is hard
>> to find answers in the docs.)
> 
> I don't see how people who don't have time to answer on llvm-dev
will
> find time to answer on some other mailing list.
> 
>> That said, I'm willing to give it a try, as an experiment. How long
>> should we attempt it for? If that's reasonably agreed to, I'll
> 
> Depends on how much time you have -- that's the limiting resource here.
> 
> However, I liked your idea of maintaining a wiki-like thing.  Both
> http://llvm.org/docs/Frontend/PerformanceTips.html and
> http://llvm.org/docs/tutorial/ will be good additions there.
> 
>> personally give it a good faith effort myself during the period.
(I'm
>> not sure I will be able to help with more than a fraction of the
>> questions, being very new at this myself, but I'll do my best.)
> 
> Thanks!
> -- Sanjoy
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