Chapter 2. Installing GHC

Table of Contents
2.1. Installing on Unix-a-likes
2.2. Installing on Windows
2.3. The layout of installed files

Installing from binary distributions is easiest, and recommended! (Why binaries? Because GHC is a Haskell compiler written in Haskell, so you've got to bootstrap it somehow. We provide machine-generated C-files-from-Haskell for this purpose, but it's really quite a pain to use them. If you must build GHC from its sources, using a binary-distributed GHC to do so is a sensible way to proceed. For the other fptools programs, many are written in Haskell, so binary distributions allow you to install them without having a Haskell compiler.)

This guide is in several parts:

2.1. Installing on Unix-a-likes

2.1.2. GHC binary distributions

Binary distributions come in “bundles,” one bundle per file called bundle-platform.tar.gz. (See the building guide for the definition of a platform.) Suppose that you untar a binary-distribution bundle, thus:

% cd /your/scratch/space
% gunzip < ghc-x.xx-sun-sparc-solaris2.tar.gz | tar xvf -

Then you should find a single directory, ghc-version, with the following structure:

Makefile.in

the raw material from which the Makefile will be made (Section 2.1.2.1).

configure

the configuration script (Section 2.1.2.1).

README

Contains this file summary.

INSTALL

Contains this description of how to install the bundle.

ANNOUNCE

The announcement message for the bundle.

NEWS

release notes for the bundle—a longer version of ANNOUNCE. For GHC, the release notes are contained in the User Guide and this file isn't present.

bin/platform

contains platform-specific executable files to be invoked directly by the user. These are the files that must end up in your path.

lib/platform/

contains platform-specific support files for the installation. Typically there is a subdirectory for each fptools project, whose name is the name of the project with its version number. For example, for GHC there would be a sub-directory ghc-x.xx/ where x.xx is the version number of GHC in the bundle.

These sub-directories have the following general structure:

libHSstd.a etc:

supporting library archives.

ghc-iface.prl etc:

support scripts.

import/

(.hi) for the prelude.

include/

A few C #include files.

share/

contains platform-independent support files for the installation. Again, there is a sub-directory for each fptools project.

html/

contains HTML documentation files (one sub-directory per project).

man/

contains Unix manual pages.

2.1.2.1. Installing

OK, so let's assume that you have unpacked your chosen bundles into a scratch directory fptools. What next? Well, you will at least need to run the configure script by changing your directory to fptools and typing ./configure. That should convert Makefile.in to Makefile.

You can now either start using the tools in-situ without going through any installation process, just type make in-place to set the tools up for this. You'll also want to add the path which make will now echo to your PATH environment variable. This option is useful if you simply want to try out the package and/or you don't have the necessary privileges (or inclination) to properly install the tools locally. Note that if you do decide to install the package `properly' at a later date, you have to go through the installation steps that follow.

To install an fptools package, you'll have to do the following:

  1. Edit the Makefile and check the settings of the following variables:

    The values for these variables can be set through invocation of the configure script that comes with the distribution, but doing an optical diff to see if the values match your expectations is always a Good Idea.

    Instead of running configure, it is perfectly OK to copy Makefile.in to Makefile and set all these variables directly yourself. But do it right!

  2. Run make install. This should work with ordinary Unix make—no need for fancy stuff like GNU make.

  3. rehash (t?csh or zsh users), so your shell will see the new stuff in your bin directory.

  4. Once done, test your “installation” as suggested in Section 2.1.2.3. Be sure to use a -v option, so you can see exactly what pathnames it's using. If things don't work as expected, check the list of known pitfalls in the building guide.

When installing the user-invokable binaries, this installation procedure will install GHC as ghc-x.xx where x.xx is the version number of GHC. It will also make a link (in the binary installation directory) from ghc to ghc-x.xx. If you install multiple versions of GHC then the last one “wins”, and “ghc” will invoke the last one installed. You can change this manually if you want. But regardless, ghc-x.xx should always invoke GHC version x.xx.