This is the source tree for GHC, a compiler and interactive environment for the Haskell functional programming language.
For more information, visit GHC's web site.
There are two ways to get a source tree:
Download source tarballs
Download the GHC source distribution:
which contains GHC itself and the "boot" libraries.
Check out the source code from git
$ git clone --recurse-submodules firstname.lastname@example.org:ghc/ghc.git
Note: cloning GHC from Github requires a special setup. See Getting a GHC repository from Github.
See the GHC team's working conventions regarding how to contribute a patch to GHC. First time contributors are encouraged to get started by just sending a Merge Request.
For full information on building GHC, see the GHC Building Guide. Here follows a summary - if you get into trouble, the Building Guide has all the answers.
Before building GHC you may need to install some other tools and libraries. See, Setting up your system for building GHC.
NB. In particular, you need GHC installed in order to build GHC, because the compiler is itself written in Haskell. You also need Happy, Alex, and Cabal. For instructions on how to port GHC to a new platform, see the GHC Building Guide.
Quick start: GHC is built using the Hadrian build system. The following gives you a default build:
$ ./boot $ ./configure $ hadrian/build # can also say '-jX' for X number of jobs
On Windows, you need an extra repository containing some build tools. These can be downloaded for you by configure. This only needs to be done once by running:
$ ./configure --enable-tarballs-autodownload
Additionally, on Windows, to run Hadrian you should run
(NB: Do you have multiple cores? Be sure to tell that to
hadrian! This can
save you hours of build time depending on your system configuration, and is
almost always a win regardless of how many cores you have. As a simple rule,
you should have about N+1 jobs, where
N is the amount of cores you have.)
./boot step is only necessary if this is a tree checked out
from git. For source distributions downloaded from GHC's web site,
this step has already been performed.
These steps give you the default build, which includes everything
optimised and built in various ways (eg. profiling libs are built).
It can take a long time. To customise the build, see the file
If you've encountered what you believe is a bug in GHC, or you'd like to propose a feature request, please let us know! Submit an issue and we'll be sure to look into it. Remember: Filing a bug is the best way to make sure your issue isn't lost over time, so please feel free.
If you're an active user of GHC, you may also be interested in joining the glasgow-haskell-users mailing list, where developers and GHC users discuss various topics and hang out.
Once you've filed a bug, maybe you'd like to fix it yourself? That
would be great, and we'd surely love your company! If you're looking
to hack on GHC, check out the guidelines in the
HACKING.md file in
this directory - they'll get you up to speed quickly.
GHC is a community project developed by a team of highly-talented researchers, individual contributors, and full-time developers. We are indebted to the many people whose work has brought GHC to its current state.
Some larger decisions are made by a smaller group of core contributors, as described in our governance documentation.