[ANNOUNCE] Shaking up GHC

[Andrey Mokhov]

Simon,

> Documenting this side-by-side possibility on the home page
> would be very helpful to up-take.

Indeed. I added a note on this at the very top of the README.

> Why not just make the 'validate' script invoke the shake build
> system (instead of 'make') when you say 'sh validate --shake'? 
> That would be simple, wouldn't it?  So shake builds GHC, and
> then 'validate' invokes 'make test' (or whatever) to run the testsuite.

Several quick attempts to reuse the validate script have failed, so I decided to start implementing a proper test rule in the new build system. (Note, I still rely on the old Python scripts for testing -- rewriting them seems to be a major undertaking.) The test rule does work for me on Windows, but the functionality is very limited at the moment. You can give it a try by running:

shake-build/build.sh test

This should run (some) tests. It shouldn't take long to make it more useful. I added a section on testing to the README: https://github.com/snowleopard/shaking-up-ghc#testing.

Cheers,
Andrey

-----Original Message-----
From: Simon Peyton Jones [mailto:simonpj at microsoft.com] 
Sent: 26 January 2016 08:55
To: Andrey Mokhov <andrey.mokhov at newcastle.ac.uk>; Ben Gamari <ben at smart-cactus.org>
Cc: ghc-devs at haskell.org
Subject: RE: [ANNOUNCE] Shaking up GHC

|  That's correct. Note though that the two build systems put (some)  
| build results in the same directories, e.g. inplace/bin/ghc-stage1, so  
| there is some interaction between them. In future it would be possible  
| to decouple them completely (if need be).

Documenting this side-by-side possibility on the home page would be very helpful to up-take.

|  > How can I do that using Shake to build?  Maybe
|  >	sh validate --shake --fast --no-clean
|  > or something?  Just modifying the validate script to make it  
| >convenient to use shake for the build part would be great.
|  
|  This may be possible precisely because binaries are where validate  
| expects them to be. I tried to pull this off, but unsuccessfully so  
| far (validate starts rebuilding everything from scratch with make). I  
| think the reason is that we changed some naming conventions for  
| directories (using stageN instead of dist, dist-boot, dist-install),  
| so validate can't find some utils. I'll let you know if I find a  
| workaround.

Why not just make the 'validate' script invoke the shake build system (instead of 'make') when you say 'sh validate --shake'?  That would be simple, wouldn't it?  So shake builds GHC, and then 'validate' invokes 'make test' (or whatever) to run the testsuite.

Little things like this would significantly increase uptake I think!

Simon



|  
|  Ben,
|  
|  > > But User.hs is a source file, which we shouldn't normally modify  
| > > lest we accidentally commit it. Could we have a non-source file to  
| > > modify (rather like  > >  
| https://na01.safelinks.protection.outlook.com/?url=build.mk&data=01%
|  > >
|  7c01%7csimonpj%40064d.mgd.microsoft.com%7c7f0edcff3c78490bd0e808d325
|  > >
|  be4774%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=8L%2b7QWlhbAwUnY
|  > > fAfCEwTXTC2PUMd17m1ceCcD2TE%2fU%3d being based on 
| build.mk.sample)  > >  > One way around this would be to add User.hs 
| to .gitignore. That way  > git will ignore changes to this files when 
| you `git commit -a`. You  > can still, however, commit changes to it 
| if you ask git explicitly.
|  
|  Yes, I was thinking about the same idea.
|  
|  Cheers,
|  Andrey
|  
|  -----Original Message-----
|  From: Simon Peyton Jones [mailto:simonpj at microsoft.com]
|  Sent: 25 January 2016 12:14
|  To: Andrey Mokhov <andrey.mokhov at newcastle.ac.uk>; ghc-  
| devs at haskell.org
|  Cc: Neil Mitchell <ndmitchell at gmail.com>; Simon Marlow  
| <marlowsd at gmail.com>
|  Subject: RE: [ANNOUNCE] Shaking up GHC
|  
|  Very good.
|  
|  As I understand it, it can work side-by-side with the existing build  
| system, correct?  That means we don't need to make an either/or  
| choice, which is very helpful.
|  
|  Every day I do
|  	sh validate --fast --no-clean
|  How can I do that using Shake to build?  Maybe
|  	sh validate --shake --fast --no-clean  or something?  Just modifying 
| the validate script to make it  convenient to use shake for the build 
| part would be great.
|  
|  You say: The make-based build system uses mk/build.mk to specify user  
| build settings. We use src/Settings/User.hs for the same purpose. Feel  
| free to experiment following the Haddock comments.
|  
|  But User.hs is a source file, which we shouldn't normally modify lest  
| we accidentally commit it.  Could we have a non-source file to modify  
| (rather like  
| https://na01.safelinks.protection.outlook.com/?url=build.mk&data=01%7c
|  
| 01%7csimonpj%40064d.mgd.microsoft.com%7c7f0edcff3c78490bd0e808d325be47
|  
| 74%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=8L%2b7QWlhbAwUnYfAfCEw
|  TXTC2PUMd17m1ceCcD2TE%2fU%3d being based on build.mk.sample)
|  
|  Simon
|  
|  |  -----Original Message-----
|  |  From: Andrey Mokhov [mailto:andrey.mokhov at newcastle.ac.uk]
|  |  Sent: 22 January 2016 14:27
|  |  To: ghc-devs at haskell.org
|  |  Cc: Simon Peyton Jones <simonpj at microsoft.com>; Neil Mitchell  | 
| <ndmitchell at gmail.com>; Simon Marlow <marlowsd at gmail.com>  |  Subject: 
| [ANNOUNCE] Shaking up GHC  |  |  Dear GHC developers,  |  |  I am 
| happy to announce that the Shaking up GHC project has finally  | 
| reached the first milestone. The goal of the project is to design a  | 
| new GHC build system based on Shake that will eventually replace the  
| | current make-based one. See the project page for more details:
|  |  https://github.com/snowleopard/shaking-up-ghc.
|  |
|  |  There is still a long way until we can match the capabilities of  
| the  | current build system. At the moment we only build vanilla way.
|  |  Validation, documentation, build flavours and cross-compilation 
| are  | not yet implemented. Known limitations are listed here:
|  |  https://github.com/snowleopard/shaking-up-ghc#current-limitations.
|  |
|  |  The purpose of this announcement is to attract alpha testers and  
| | collect early feedback across multiple platforms and build  | 
| configurations. We already have several success reports on Linux, OS  
| | X, Solaris and Windows. However, things will inevitably break and we  
| | hope to catch and fix as many of these cases as possible with your  
| | help. The instructions on how to try the new build system can be  
| found  |  here: 
| https://github.com/snowleopard/shaking-up-ghc#your-first-
|  build.
|  |
|  |  We plan to be ready to become a part of the GHC tree around 1 
| March  | 2016, and catch up with the make build system around 1 June 2016.
|  The
|  | dates are tentative and depend on how much time it takes us to  
| resolve  | the remaining issues: 
| https://github.com/snowleopard/shaking-up-
|  |  ghc/milestones.
|  |
|  |  I would like thank everyone who contributed to this project so far:
|  |  Simon Peyton Jones, Neil Mitchell and Simon Marlow came up with 
| the  | idea and guided me throughout the project; Moritz Angermann, 
| Ben  | Gamari, Karel Gardas, David Luposchainsky, and Neil Mitchell  | 
| contributed to the codebase. Thank you all!
|  |
|  |  Kind regards,
|  |  Andrey