The Glasgow Haskell Compiler
============================

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:

  http://www.haskell.org/ghc/

Information for developers of GHC can be found here:

  http://hackage.haskell.org/trac/ghc/


Getting the Source
==================

There are two ways to get a source tree:

  1. Download source tarballs
  ---------------------------

  The GHC source distribution comes in two parts:

      ghc-<version>-src.tar.bz2
      ghc-<version>-src-extralibs.tar.bz2

  You only need the first one, which contains GHC itself and
  the "boot" libraries.

  The extralibs package contains a bunch of optional libraries.  If
  you want, you can unpack this over the top of your source tree, and
  these extra libraries will be built and installed automatically.
  Make sure you unpack the extralibs package before running configure
  (see below).

  If you don't build extralibs now, you can add them later by building
  and installing individual packages using Cabal.

  2. Get the source from darcs
  ----------------------------

  First get the GHC darcs repository:

    $ darcs get http://darcs.haskell.org/ghc/

  Then run the darcs-all script in that repository
  to get the other repositories:

     $ cd ghc
     $ chmod +x darcs-all
     $ ./darcs-all get

  This grabs the "boot" packages by default.  To get the full set of
  packages, instead say

     $ ./darcs-all --extra get

  This also downloads the libraries that are normally bundled in the
  "extralibs" package (see above).


Building & Installing
=====================

For full information on building GHC, see the GHC Building Guide [3].
Here follows a summary - if you get into trouble, the Building Guide
has all the answers.

NB. you need GHC installed in order to build GHC, because the compiler
is itself written in Haskell.  It is possible to build GHC using just
a C compiler, but we don't recommend this as the normal route.  If you
*really* want to do it this way, then see the Building Guide.

If you're building from darcs sources (as opposed to a source
distribution) then you also need to install Happy [4] and Alex [5].

For building library documentation, you'll need Haddock [6].  To build
the compiler documentation, you need a good DocBook XML toolchain.

Quick start:  the following gives you a default build:

    $ sh boot
    $ ./configure
    $ make
    $ make install

The "sh boot" step is only necessary if this is a tree checked out
from darcs.  For source distributions downloaded from GHC's web site,
this step has already been performed.

If you want the documentation too then use these commands instead:

    $ echo "XMLDocWays   = html" > mk/build.mk
    $ echo "HADDOCK_DOCS = YES" >> mk/build.mk
    $ sh boot
    $ ./configure
    $ make
    $ make install
    $ make install-docs

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
HACKING.



References
==========

 [1] http://www.haskell.org/ghc/                        GHC Home Page
 [2] http://hackage.haskell.org/trac/ghc                GHC Developer's Wiki
 [3] http://hackage.haskell.org/trac/ghc/wiki/Building  Building Guide
 [4] http://www.haskell.org/happy/                      Happy
 [5] http://www.haskell.org/alex/                       Alex
 [6] http://www.haskell.org/haddock/                    Haddock


Contributors
============

Please see

   http://www.haskell.org/ghc/contributors.html