llvm dev - Aug 2009 - [LLVMdev] LLVMContext: Suggestions for API Changes

Owen Anderson wrote:
> On Jul 15, 2009, at 10:56 AM, Jean-Daniel Dupas wrote:
>>
>> You mean like this subject ? 
>>
>> http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-June/023505.html
> 
> Notice the sender line on that email... ;-)
Yes, you indeed announced that change, but as John rightfully remarked,
the announcement gave little detail. For LLVM users like me, who just,
well, *use* LLVM, this wasn't enough. Maybe it's not time to document
the changes yet, and maybe everybody but the LLVM developers should stop
using LLVM from svn for a while until the API stabilizes again. That's
fine with me. I can only politely ask that at some point someone please
provide us with the information that we need to port our stuff to the
new API so that we don't have to spend days digging through the LLVM
source code. ;-)

Thanks,
Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr.Graef at t-online.de, ag at muwiinfa.geschichte.uni-mainz.de
WWW:    http://www.musikinformatik.uni-mainz.de/ag

On Jul 15, 2009, at 2:24 PM, Albert Graef wrote:
> Yes, you indeed announced that change, but as John rightfully  
> remarked,
> the announcement gave little detail. For LLVM users like me, who just,
> well, *use* LLVM, this wasn't enough. Maybe it's not time to
document
> the changes yet, and maybe everybody but the LLVM developers should  
> stop
> using LLVM from svn for a while until the API stabilizes again. That's
> fine with me. I can only politely ask that at some point someone  
> please
> provide us with the information that we need to port our stuff to the
> new API so that we don't have to spend days digging through the LLVM
> source code. ;-)
http://llvm.org/docs/ReleaseNotes-2.6.html#whatsnew

See the "Major Changes and Removed Features" section, which is  
obviously still a work in progress until 2.6 ships.

--Owen

On Wed, Jul 15, 2009 at 2:24 PM, Albert Graef<Dr.Graef at t-online.de>
wrote:
> Owen Anderson wrote:
>> On Jul 15, 2009, at 10:56 AM, Jean-Daniel Dupas wrote:
>>>
>>> You mean like this subject ?
>>>
>>> http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-June/023505.html
>>
>> Notice the sender line on that email... ;-)
>
> Yes, you indeed announced that change, but as John rightfully remarked,
> the announcement gave little detail. For LLVM users like me, who just,
> well, *use* LLVM, this wasn't enough. Maybe it's not time to
document
> the changes yet, and maybe everybody but the LLVM developers should stop
> using LLVM from svn for a while until the API stabilizes again. That's
> fine with me. I can only politely ask that at some point someone please
> provide us with the information that we need to port our stuff to the
> new API so that we don't have to spend days digging through the LLVM
> source code. ;-)
See Owen's email about docs for the 2.6 release, but it's really not
that hard to keep up with trunk. I recently merged trunk LLVM into
Unladen Swallow, and the changes I needed to make are at
http://code.google.com/p/unladen-swallow/source/detail?r=724. You get
some compiler errors saying that an LLVMContext parameter is missing;
you grep the source for LLVMContext, finding
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/LLVMContext.h?view=markup;
you read that and find the "/// FOR BACKWARDS COMPATIBILITY" line at
the bottom; and you pass getGlobalContext() all over the place until
the compiler's happy.

The InitializeNativeTarget() change was harder to discover, but it
wasn't that hard to search the list for.

Albert Graef wrote:
> Yes, you indeed announced that change, but as John rightfully remarked,
> the announcement gave little detail. For LLVM users like me, who just,
> well, *use* LLVM, this wasn't enough. Maybe it's not time to
document
> the changes yet, and maybe everybody but the LLVM developers should stop
> using LLVM from svn for a while until the API stabilizes again. That's
> fine with me. I can only politely ask that at some point someone please
> provide us with the information that we need to port our stuff to the
> new API so that we don't have to spend days digging through the LLVM
> source code. ;-)
I think a timeline would help.  That is, if the developers made a point of
saying "we expect the API on trunk to be volatile for the next two
weeks",
then users would be able to make their own decisions about whether to
try to track the changes.  It also makes it easier for developers to 
document
how to adapt to the new API, because you can make one guide when you
know how it all works instead of maintaining (or failing to maintain) a
constantly-shifting document of momentary kludges and workarounds.

The downside, of course, is that it would encourage users to not stay
current for a few weeks, which hurts all the other active development.

John.

Jeffrey Yasskin wrote:
> See Owen's email about docs for the 2.6 release, but it's really
not
> that hard to keep up with trunk. I recently merged trunk LLVM into
> Unladen Swallow, and the changes I needed to make are at
> http://code.google.com/p/unladen-swallow/source/detail?r=724.
Thanks Jeffrey, that was really very helpful! I have Pure working with
both the LLVM 2.6 release branch and the trunk now.

One thing I noticed is that writing LLVM assembler code (print()
methods) seems to be horribly slow now (some 4-5 times slower than in
LLVM 2.5). This is a real bummer for me, since Pure's batch compiler
uses those methods to produce output code which then gets fed into llvmc.

Is this a known problem? Will it be fixed until the 2.6 release?

Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr.Graef at t-online.de, ag at muwiinfa.geschichte.uni-mainz.de
WWW:    http://www.musikinformatik.uni-mainz.de/ag