1 <!DOCTYPE Article PUBLIC "-//OASIS//DTD DocBook V3.1//EN">
3 <Article id="building-guide">
7 <Title>Building the Glasgow Functional Programming Tools Suite</Title>
8 <Author><OtherName>The GHC Team</OtherName></Author>
9 <Address><Email>glasgow-haskell-{users,bugs}@haskell.org</Email></Address>
10 <PubDate>November 2001</PubDate>
13 <para>The Glasgow fptools suite is a collection of Functional
14 Programming related tools, including the Glasgow Haskell
15 Compiler (GHC). The source code for the whole suite is kept in
16 a single CVS repository and shares a common build and
17 installation system.</para>
19 <para>This guide is intended for people who want to build or
20 modify programs from the Glasgow <Literal>fptools</Literal>
21 suite (as distinct from those who merely want to
22 <Emphasis>run</Emphasis> them). Installation instructions are
23 now provided in the user guide.</para>
25 <para>The bulk of this guide applies to building on Unix
26 systems; see <XRef LinkEnd="winbuild"> for Windows notes.</para>
32 <sect1 id="sec-getting">
33 <title>Getting the Glasgow <Literal>fptools</Literal> suite</title>
35 <para>Building the Glasgow tools <Emphasis>can</Emphasis> be
36 complicated, mostly because there are so many permutations of
37 what/why/how, e.g., ``Build Happy with HBC, everything else with
38 GHC, leave out profiling, and test it all on the `real' NoFib
39 programs.'' Yeeps!</para>
41 <para>Happily, such complications don't apply to most people. A
42 few common ``strategies'' serve most purposes. Pick one and
43 proceed as suggested:</para>
48 <term><indexterm><primary>Binary distribution</primary></indexterm>Binary distribution.</term>
51 If your only purpose is to install some of the
52 <Literal>fptools</Literal> suite then the easiest thing to do is to
53 get a binary distribution. In the binary distribution everything is
54 pre-compiled for your particular machine architecture and operating
55 system, so all you should have to do is install the binaries and
56 libraries in suitable places. The user guide describes how to do this.
60 A binary distribution may not work for you for two reasons. First, we
61 may not have built the suite for the particular architecture/OS
62 platform you want. That may be due to lack of time and energy (in
63 which case you can get a source distribution and build from it; see
64 below). Alternatively, it may be because we haven't yet ported the
65 suite to your architecture, in which case you are considerably worse
70 The second reason a binary distribution may not be what you want is
71 if you want to read or modify the souce code.
73 </listitem></VarListEntry>
75 <term><indexterm><primary>Source distribution</primary></indexterm>Source distribution.</term>
79 platform, but (a) you like the warm fuzzy feeling of compiling things
80 yourself; (b) you want to build something ``extra''—e.g., a set of
81 libraries with strictness-analysis turned off; or (c) you want to hack
86 A source distribution contains complete sources for one or more
87 projects in the <Literal>fptools</Literal> suite. Not only that, but
88 the more awkward machine-independent steps are done for you. For
89 example, if you don't have
90 <Command>happy</Command><indexterm><primary>happy</primary></indexterm>
91 you'll find it convenient that the source distribution contains the
92 result of running <Command>happy</Command> on the parser
93 specifications. If you don't want to alter the parser then this saves
94 you having to find and install <Command>happy</Command>. You will
95 still need a working version of GHC (preferably version 4.08+) on your
96 machine in order to compile (most of) the sources, however.
99 </listitem></VarListEntry>
102 <term>The CVS repository.</term>
103 <indexterm><primary>CVS repository</primary>
106 <para>We make releases infrequently. If you want more
107 up-to-the minute (but less tested) source code then you need
108 to get access to our CVS repository.</para>
110 <para>All the <Literal>fptools</Literal> source code is held
111 in a CVS repository. CVS is a pretty good source-code
112 control system, and best of all it works over the
115 <para>The repository holds source code only. It holds no
116 mechanically generated files at all. So if you check out a
117 source tree from CVS you will need to install every utility
118 so that you can build all the derived files from
121 <para>More information about our CVS repository can be found
122 in <xref linkend="sec-cvs">.</para>
128 <term>Build GHC from intermediate C <Filename>.hc</Filename> files<indexterm><primary>hc files</primary></indexterm>:</term>
130 <para><emphasis>NOTE: GHC version 5.xx is significantly
131 harder to bootstrap from C than previous versions. We
132 recommend starting from version 4.08.2 if you need to
133 bootstrap in this way.</emphasis></para>
135 <para>You need a working GHC to use a source distribution.
136 What if you don't have a working GHC? Then you may be able
137 to bootstrap up from the intermediate C
138 (<filename>.hc</filename>) files that we provide. Building
139 GHC on an unsupported platform falls into this category.
140 Beware: this route is not for the faint hearted! Please see
141 <Xref LinkEnd="sec-booting-from-C">.</para>
143 <para>Once you have built GHC, you can build the other
144 Glasgow tools with it.</para>
146 <para>In theory, you can (could?) build GHC with another
147 Haskell compiler (e.g., HBC). We haven't tried to do this
148 for ages and it almost certainly doesn't work any more (for
149 tedious reasons).</para>
154 <para>If you are going to do any building from sources (either
155 from a source distribution or the CVS repository) then you need to
156 read all of this manual in detail.</para>
160 <title>Using the CVS repository</title>
162 <para>We use <ulink url="http://www.cvshome.org/">CVS</ulink> (Concurrent Version System) to keep track of our
163 sources for various software projects. CVS lets several people
164 work on the same software at the same time, allowing changes to be
165 checked in incrementally. </para>
167 <para>This section is a set of guidelines for how to use our CVS
168 repository, and will probably evolve in time. The main thing to
169 remember is that most mistakes can be undone, but if there's
170 anything you're not sure about feel free to bug the local CVS
171 meister (namely Jeff Lewis
172 <email>jlewis@galconn.com</email>). </para>
174 <sect2 id="cvs-access">
175 <title>Getting access to the CVS Repository</title>
177 <para>You can access the repository in one of two ways:
178 read-only (<xref linkend="cvs-read-only">), or read-write (<xref
179 linkend="cvs-read-write">).</para>
181 <sect3 id="cvs-read-only">
182 <title>Remote Read-only CVS Access</title>
184 <para>Read-only access is available to anyone - there's no
185 need to ask us first. With read-only CVS access you can do
186 anything except commit changes to the repository. You can
187 make changes to your local tree, and still use CVS's merge
188 facility to keep your tree up to date, and you can generate
189 patches using 'cvs diff' in order to send to us for
192 <para>To get read-only access to the repository:</para>
196 <para>Make sure that <application>cvs</application> is
197 installed on your machine.</para>
200 <para>Set your <literal>$CVSROOT</literal> environment variable to
201 <literal>:pserver:anoncvs@glass.cse.ogi.edu:/cvs</literal></para>
204 <para>Run the command</para>
208 <para>The password is simply <literal>cvs</literal>. This
209 sets up a file in your home directory called
210 <literal>.cvspass</literal>, which squirrels away the
211 dummy password, so you only need to do this step once.</para>
215 <para>Now go to <xref linkend="cvs-first">.</para>
220 <sect3 id="cvs-read-write">
221 <title>Remote Read-Write CVS Access</title>
223 <para>We generally supply read-write access to folk doing
224 serious development on some part of the source tree, when
225 going through us would be a pain. If you're developing some
226 feature, or think you have the time and inclination to fix
227 bugs in our sources, feel free to ask for read-write
228 access. There is a certain amount of responsibility that goes
229 with commit privileges; we are more likely to grant you access
230 if you've demonstrated your competence by sending us patches
231 via mail in the past.</para>
233 <para>To get remote read-write CVS access, you need to do the
234 following steps.</para>
238 <para>Make sure that <literal>cvs</literal> and
239 <literal>ssh</literal> are both installed on your
244 <para>Generate a DSA private-key/public-key pair, thus:</para>
248 <para>(<literal>ssh-keygen</literal> comes with
249 <literal>ssh</literal>.) Running <literal>ssh-keygen
250 -d</literal> creates the private and public keys in
251 <literal>$HOME/.ssh/id_dsa</literal> and
252 <literal>$HOME/.ssh/id_dsa.pub</literal> respectively
253 (assuming you accept the standard defaults).</para>
255 <para><literal>ssh-keygen -d</literal> will only work if
256 you have Version 2 <literal>ssh</literal> installed; it
257 will fail harmlessly otherwise. If you only have Version
258 1 you can instead generate an RSA key pair using plain</para>
263 <para>Doing so creates the private and public RSA keys in
264 <literal>$HOME/.ssh/identity</literal> and
265 <literal>$HOME/.ssh/identity.pub</literal>
268 <para>[Deprecated.] Incidentally, you can force a Version
269 2 <literal>ssh</literal> to use the Version 1 protocol by
270 creating <literal>$HOME/config</literal> with the
271 following in it:</para>
279 <para>In both cases, <literal>ssh-keygen</literal> will
280 ask for a <firstterm>passphrase</firstterm>. The
281 passphrase is a password that protects your private key.
282 In response to the 'Enter passphrase' question, you can
286 <para>[Recommended.] Enter a passphrase, which you
287 will quote each time you use CVS.
288 <literal>ssh-agent</literal> makes this entirely
292 <para>[Deprecated.] Just hit return (i.e. use an empty
293 passphrase); then you won't need to quote the
294 passphrase when using CVS. The downside is that
295 anyone who can see into your <literal>.ssh</literal>
296 directory, and thereby get your private key, can mess
297 up the repository. So you must keep the
298 <literal>.ssh</literal> directory with draconian
299 no-access permissions.</para>
305 [Windows users.] The programs <command>ssh-keygen1</command>, <command>ssh1</command>, and <command>cvs</command>,
306 seem to lock up <command>bash</command> entirely if they try to get user input (e.g. if
307 they ask for a password). To solve this, start up <filename>cmd.exe</filename>
308 and run it as follows:
310 c:\tmp> set CYGWIN32=tty
311 c:\tmp> c:/user/local/bin/ssh-keygen1
314 <para>[Windows users.] To protect your
315 <literal>.ssh</literal> from access by anyone else,
316 right-click your <literal>.ssh</literal> directory, and
317 select <literal>Properties</literal>. If you are not on
318 the access control list, add yourself, and give yourself
319 full permissions (the second panel). Remove everyone else
320 from the access control list. Don't leave them there but
321 deny them access, because 'they' may be a list that
326 <para>Send a message to to the CVS repository
327 administrator (currently Jeff Lewis
328 <email>jeff@galconn.com</email>), containing:</para>
331 <para>Your desired user-name.</para>
334 <para>Your <literal>.ssh/id_dsa.pub</literal> (or
335 <literal>.ssh/identity.pub</literal>).</para>
338 <para>He will set up your account.</para>
342 <para>Set the following environment variables:</para>
346 <constant>$HOME</constant>: points to your home directory. This is where CVS
347 will look for its <filename>.cvsrc</filename> file.
353 <constant>$CVS_RSH</constant> to <filename>ssh</filename>
355 <para>[Windows users.] Setting your <literal>CVS_RSH</literal> to
356 <literal>ssh</literal> assumes that your CVS client
357 understands how to execute shell script
358 ("#!"s,really), which is what
359 <literal>ssh</literal> is. This may not be the case on
360 Win32 platforms, so in that case set <literal>CVS_RSH</literal> to
361 <literal>ssh1</literal>.</para>
365 <para><literal>$CVSROOT</literal> to
366 <literal>:ext:</literal><replaceable>your-username</replaceable>
367 <literal>@cvs.haskell.org:/home/cvs/root</literal>
368 where <replaceable>your-username</replaceable> is your user name on
369 <literal>cvs.haskell.org</literal>.
371 <para>The <literal>CVSROOT</literal> environment variable will
372 be recorded in the checked-out tree, so you don't need to set
373 this every time. </para>
379 <constant>$CVSEDITOR</constant>: <filename>bin/gnuclient.exe</filename>
380 if you want to use an Emacs buffer for typing in those long commit messages.
386 <constant>$SHELL</constant>: To use bash as the shell in Emacs, you need to
387 set this to point to <Filename>bash.exe</Filename>.
398 Put the following in <filename>$HOME/.cvsrc</filename>:
409 These are the default options for the specified CVS commands,
410 and represent better defaults than the usual ones. (Feel
411 free to change them.)
415 [Windows users.] Filenames starting with <filename>.</filename> were illegal in
416 the 8.3 DOS filesystem, but that restriction should have
417 been lifted by now (i.e., you're using VFAT or later filesystems.) If
418 you're still having problems creating it, don't worry; <filename>.cvsrc</filename> is entirely
426 <para>[Experts.] Once your account is set up, you can get
427 access from other machines without bothering Jeff, thus:</para>
430 <para>Generate a public/private key pair on the new
434 <para>Use ssh to log in to
435 <literal>cvs.haskell.org</literal>, from your old
439 <para>Add the public key for the new machine to the file
440 <literal>$HOME/ssh/authorized_keys</literal> on
441 <literal>cvs.haskell.org</literal>.
442 (<literal>authorized_keys2</literal>, I think, for Version
446 <para>Make sure that the new version of
447 <literal>authorized_keys</literal> still has 600 file
456 <sect2 id="cvs-first">
457 <title>Checking Out a Source Tree</title>
461 <para>Make sure you set your <literal>CVSROOT</literal>
462 environment variable according to either of the remote
463 methods above. The Approved Way to check out a source tree
464 is as follows:</para>
467 $ cvs checkout fpconfig
470 <para>At this point you have a new directory called
471 <literal>fptools</literal> which contains the basic stuff
472 for the fptools suite, including the configuration files and
473 some other junk. </para>
475 <para>[Windows users.] The following messages appear to be harmless:
477 setsockopt IPTOS_LOWDELAY: Invalid argument
478 setsockopt IPTOS_THROUGHPUT: Invalid argument
483 <para>You can call the fptools directory whatever you like,
484 CVS won't mind: </para>
487 $ mv fptools <replaceable>directory</replaceable>
490 <para> NB: after you've read the CVS manual you might be
491 tempted to try</para>
493 $ cvs checkout -d <replaceable>directory</replaceable> fpconfig
496 <para>instead of checking out <literal>fpconfig</literal>
497 and then renaming it. But this doesn't work, and will
498 result in checking out the entire repository instead of just
499 the <literal>fpconfig</literal> bit.</para>
501 $ cd <replaceable>directory</replaceable>
502 $ cvs checkout ghc hslibs
505 <para>The second command here checks out the relevant
506 modules you want to work on. For a GHC build, for instance,
507 you need at least the <literal>ghc</literal> and
508 <literal>hslibs</literal> modules (for a full list of the
509 projects available, see <xref linkend="projects">).</para>
514 <sect2 id="cvs-committing">
515 <title>Committing Changes</title>
517 <para>This is only if you have read-write access to the
518 repository. For anoncvs users, CVS will issue a "read-only
519 repository" error if you try to commit changes.</para>
523 <para>Build the software, if necessary. Unless you're just
524 working on documentation, you'll probably want to build the
525 software in order to test any changes you make.</para>
529 <para>Make changes. Preferably small ones first.</para>
533 <para>Test them. You can see exactly what changes you've
534 made by using the <literal>cvs diff</literal> command:</para>
538 <para>lists all the changes (using the
539 <literal>diff</literal> command) in and below the current
540 directory. In emacs, <literal>C-c C-v =</literal> runs
541 <literal>cvs diff</literal> on the current buffer and shows
542 you the results.</para>
546 <para>Before checking in a change, you need to update your
553 <para>This pulls in any changes that other people have made,
554 and merges them with yours. If there are any conflicts, CVS
555 will tell you, and you'll have to resolve them before you
556 can check your changes in. The documentation describes what
557 to do in the event of a conflict.</para>
559 <para>It's not always necessary to do a full cvs update
560 before checking in a change, since CVS will always tell you
561 if you try to check in a file that someone else has changed.
562 However, you should still update at regular intervals to
563 avoid making changes that don't work in conjuction with
564 changes that someone else made. Keeping an eye on what goes
565 by on the mailing list can help here.</para>
569 <para>When you're happy that your change isn't going to
570 break anything, check it in. For a one-file change:</para>
573 $ cvs commit <replaceable>filename</replaceable>
576 <para>CVS will then pop up an editor for you to enter a
577 "commit message", this is just a short description
578 of what your change does, and will be kept in the history of
581 <para>If you're using emacs, simply load up the file into a
582 buffer and type <literal>C-x C-q</literal>, and emacs will
583 prompt for a commit message and then check in the file for
586 <para>For a multiple-file change, things are a bit
587 trickier. There are several ways to do this, but this is the
588 way I find easiest. First type the commit message into a
589 temporary file. Then either</para>
592 $ cvs commit -F <replaceable>commit-message</replaceable> <replaceable>file_1</replaceable> .... <replaceable>file_n</replaceable>
595 <para>or, if nothing else has changed in this part of the
599 $ cvs commit -F <replaceable>commit-message</replaceable> <replaceable>directory</replaceable>
602 <para>where <replaceable>directory</replaceable> is a common
603 parent directory for all your changes, and
604 <replaceable>commit-message</replaceable> is the name of the
605 file containing the commit message.</para>
607 <para>Shortly afterwards, you'll get some mail from the
608 relevant mailing list saying which files changed, and giving
609 the commit message. For a multiple-file change, you should
610 still get only <emphasis>one</emphasis> message.</para>
615 <sect2 id="cvs-update">
616 <title>Updating Your Source Tree</title>
618 <para>It can be tempting to cvs update just part of a source
619 tree to bring in some changes that someone else has made, or
620 before committing your own changes. This is NOT RECOMMENDED!
621 Quite often changes in one part of the tree are dependent on
622 changes in another part of the tree (the
623 <literal>mk/*.mk</literal> files are a good example where
624 problems crop up quite often). Having an inconsistent tree is a
625 major cause of headaches. </para>
627 <para>So, to avoid a lot of hassle, follow this recipe for
628 updating your tree: </para>
632 $ cvs update -Pd 2>&1 | tee log</screen>
634 <para>Look at the log file, and fix any conflicts (denoted by a
635 <quote>C</quote> in the first column). If you're using multiple
636 build trees, then for every build tree you have pointing at this
637 source tree, you need to update the links in case any new files
638 have appeared: </para>
641 $ cd <replaceable>build-tree</replaceable>
642 $ lndir <replaceable>source-tree</replaceable>
645 <para>Some files might have been removed, so you need to remove
646 the links pointing to these non-existent files:</para>
649 $ find . -xtype l -exec rm '{}' \;
652 <para>To be <emphasis>really</emphasis> safe, you should do
655 <screen>$ gmake all</screen>
657 <para>from the top-level, to update the dependencies and build
658 any changed files. </para>
661 <sect2 id="cvs-tags">
662 <title>GHC Tag Policy</title>
664 <para>If you want to check out a particular version of GHC,
665 you'll need to know how we tag versions in the repository. The
666 policy (as of 4.04) is:</para>
670 <para>The tree is branched before every major release. The
671 branch tag is <literal>ghc-x-xx-branch</literal>, where
672 <literal>x-xx</literal> is the version number of the release
673 with the <literal>'.'</literal> replaced by a
674 <literal>'-'</literal>. For example, the 4.04 release lives
675 on <literal>ghc-4-04-branch</literal>.</para>
679 <para>The release itself is tagged with
680 <literal>ghc-x-xx</literal> (on the branch). eg. 4.06 is
681 called <literal>ghc-4-06</literal>.</para>
685 <para>We didn't always follow these guidelines, so to see
686 what tags there are for previous versions, do <literal>cvs
687 log</literal> on a file that's been around for a while (like
688 <literal>fptools/ghc/README</literal>).</para>
692 <para>So, to check out a fresh GHC 4.06 tree you would
696 $ cvs co -r ghc-4-06 fpconfig
698 $ cvs co -r ghc-4-06 ghc hslibs
702 <sect2 id="cvs-hints">
703 <title>General Hints</title>
707 <para>As a general rule: commit changes in small units,
708 preferably addressing one issue or implementing a single
709 feature. Provide a descriptive log message so that the
710 repository records exactly which changes were required to
711 implement a given feature/fix a bug. I've found this
712 <emphasis>very</emphasis> useful in the past for finding out
713 when a particular bug was introduced: you can just wind back
714 the CVS tree until the bug disappears.</para>
718 <para>Keep the sources at least *buildable* at any given
719 time. No doubt bugs will creep in, but it's quite easy to
720 ensure that any change made at least leaves the tree in a
721 buildable state. We do nightly builds of GHC to keep an eye
722 on what things work/don't work each day and how we're doing
723 in relation to previous verions. This idea is truely wrecked
724 if the compiler won't build in the first place!</para>
728 <para>To check out extra bits into an already-checked-out
729 tree, use the following procedure. Suppose you have a
730 checked-out fptools tree containing just ghc, and you want
731 to add nofib to it:</para>
742 $ cvs update -d nofib
745 <para>(the -d flag tells update to create a new
746 directory). If you just want part of the nofib suite, you
751 $ cvs checkout nofib/spectral
754 <para>This works because <literal>nofib</literal> is a
755 module in its own right, and spectral is a subdirectory of
756 the nofib module. The path argument to checkout must always
757 start with a module name. There's no equivalent form of this
758 command using <literal>update</literal>.</para>
764 <sect1 id="projects">
765 <title>What projects are there?</title>
767 <para>The <literal>fptools</literal> suite consists of several
768 <firstterm>projects</firstterm>, most of which can be downloaded,
769 built and installed individually. Each project corresponds to a
770 subdirectory in the source tree, and if checking out from CVS then
771 each project can be checked out individually by sitting in the top
772 level of your source tree and typing <command>cvs checkout
773 <replaceable>project</replaceable></command>.</para>
775 <para>Here is a list of the projects currently available:</para>
779 <term><literal>ghc</literal></term>
780 <indexterm><primary><literal>ghc</literal></primary>
781 <secondary>project</secondary></indexterm>
783 <para>The <ulink url="http://www.haskell.org/ghc/">Glasgow
784 Haskell Compiler</ulink> (minus libraries). Absolutely
785 required for building GHC.</para>
790 <term><literal>glafp-utils</literal></term>
791 <indexterm><primary><literal>glafp-utils</literal></primary><secondary>project</secondary></indexterm>
793 <para>Utility programs, some of which are used by the
794 build/installation system. Required for pretty much
800 <term><literal>green-card</literal></term>
801 <indexterm><primary><literal>green-card</literal></primary><secondary>project</secondary></indexterm>
804 url="http://www.haskell.org/greencard/">Green Card</ulink>
805 system for generating Haskell foreign function
811 <term><literal>haggis</literal></term>
812 <indexterm><primary><literal>haggis</literal></primary><secondary>project</secondary></indexterm>
815 url="http://www.dcs.gla.ac.uk/fp/software/haggis/">Haggis</ulink>
816 Haskell GUI framework.</para>
821 <term><literal>happy</literal></term>
822 <indexterm><primary><literal>happy</literal></primary><secondary>project</secondary></indexterm>
825 url="http://www.haskell.org/happy/">Happy</ulink> Parser
831 <term><literal>hdirect</literal></term>
832 <indexterm><primary><literal>hdirect</literal></primary><secondary>project</secondary></indexterm>
835 url="http://www.haskell.org/hdirect/">H/Direct</ulink>
836 Haskell interoperability tool.</para>
841 <term><literal>hood</literal></term>
842 <indexterm><primary><literal>hood</literal></primary><secondary>project</secondary></indexterm>
844 <para>The <ulink url="http://www.haskell.org/hood/">Haskell
845 Object Observation Debugger</ulink>.</para>
850 <term><literal>hslibs</literal></term>
851 <indexterm><primary><literal>hslibs</literal></primary><secondary>project</secondary></indexterm>
853 <para>GHC's libraries. Required for building GHC.</para>
858 <term><literal>libraries</literal></term>
859 <indexterm><primary><literal></literal></primary><secondary>project</secondary></indexterm>
861 <para>Hierarchical Haskell library suite
862 (experimental).</para>
867 <term><literal>mhms</literal></term>
868 <indexterm><primary><literal></literal></primary><secondary>project</secondary></indexterm>
870 <para>The Modular Haskell Metric System.</para>
875 <term><literal>nofib</literal></term>
876 <indexterm><primary><literal>nofib</literal></primary><secondary>project</secondary></indexterm>
878 <para>The NoFib suite: A collection of Haskell programs used
879 primarily for benchmarking.</para>
884 <term><literal>testsuite</literal></term>
885 <indexterm><primary><literal>testsuite</literal></primary><secondary>project</secondary></indexterm>
887 <para>A testing framework, including GHC's regression test
893 <para>So, to build GHC you need at least the
894 <literal>ghc</literal> and <literal>hslibs</literal> projects (a
895 GHC source distribution will already include the bits you
899 <sect1 id="sec-build-checks">
900 <title>Things to check before you start</title>
902 <para>Here's a list of things to check before you get
908 <indexterm><primary>Disk space needed</primary></indexterm>
909 <para>Disk space needed: from about 100Mb for a basic GHC
910 build, up to probably 500Mb for a GHC build with everything
911 included (libraries built several different ways,
916 <para>Use an appropriate machine, compilers, and things.
917 SPARC boxes, PCs running Linux or FreeBSD, and Alphas running
918 OSF/1 are all fully supported. Win32 and HP boxes are in
919 pretty good shape. PCs running Solaris, DEC Alphas running
920 Linux or some BSD variant, MIPS and AIX boxes will need some
921 minimal porting effort before they work (as of 4.06). <xref
922 linkend="sec-port-info"> gives the full run-down on ports or
927 <para>Be sure that the ``pre-supposed'' utilities are
928 installed. <Xref LinkEnd="sec-pre-supposed">
933 <para>If you have any problem when building or installing the
934 Glasgow tools, please check the ``known pitfalls'' (<Xref
935 LinkEnd="sec-build-pitfalls">). Also check the FAQ for the
936 version you're building, which should be available from the
937 relevant download page on the <ULink
938 URL="http://www.haskell.org/ghc/" >GHC web
941 <indexterm><primary>known bugs</primary></indexterm>
942 <indexterm><primary>bugs, known</primary></indexterm>
944 <para>If you feel there is still some shortcoming in our
945 procedure or instructions, please report it.</para>
947 <para>For GHC, please see the bug-reporting section of the GHC
948 Users' Guide (separate document), to maximise the usefulness
949 of your report.</para>
951 <indexterm><primary>bugs</primary><secondary>seporting</secondary></indexterm>
953 <para>If in doubt, please send a message to
954 <email>glasgow-haskell-bugs@haskell.org</email>.
955 <indexterm><primary>bugs</primary><secondary>mailing
956 list</secondary></indexterm></para>
962 <Sect1 id="sec-port-info">
963 <Title>What machines the Glasgow tools run on
967 <indexterm><primary>ports, GHC</primary></indexterm>
968 <indexterm><primary>GHC ports</primary></indexterm>
969 <indexterm><primary>supported platforms</primary></indexterm>
970 <indexterm><primary>platforms, supported</primary></indexterm>
971 The main question is whether or not the Haskell compiler (GHC) runs on
976 A ``platform'' is a architecture/manufacturer/operating-system
977 combination, such as <Literal>sparc-sun-solaris2</Literal>. Other common ones are
978 <Literal>alpha-dec-osf2</Literal>, <Literal>hppa1.1-hp-hpux9</Literal>, <Literal>i386-unknown-linux</Literal>,
979 <Literal>i386-unknown-solaris2</Literal>, <Literal>i386-unknown-freebsd</Literal>,
980 <Literal>i386-unknown-cygwin32</Literal>, <Literal>m68k-sun-sunos4</Literal>, <Literal>mips-sgi-irix5</Literal>,
981 <Literal>sparc-sun-sunos4</Literal>, <Literal>sparc-sun-solaris2</Literal>, <Literal>powerpc-ibm-aix</Literal>.
985 Bear in mind that certain ``bundles'', e.g. parallel Haskell, may not
986 work on all machines for which basic Haskell compiling is supported.
990 Some libraries may only work on a limited number of platforms; for
991 example, a sockets library is of no use unless the operating system
992 supports the underlying BSDisms.
996 <Title>What platforms the Haskell compiler (GHC) runs on</Title>
999 <indexterm><primary>fully-supported platforms</primary></indexterm>
1000 <indexterm><primary>native-code generator</primary></indexterm>
1001 <indexterm><primary>registerised ports</primary></indexterm>
1002 <indexterm><primary>unregisterised ports</primary></indexterm>
1003 The GHC hierarchy of Porting Goodness: (a) Best is a native-code
1004 generator; (b) next best is a ``registerised''
1005 port; (c) the bare minimum is an ``unregisterised'' port.
1006 (``Unregisterised'' is so terrible that we won't say more about it).
1010 We use Sparcs running Solaris 2.7 and x86 boxes running FreeBSD and
1011 Linux, so those are the best supported platforms, unsurprisingly.
1015 Here's everything that's known about GHC ports. We identify platforms
1016 by their ``canonical'' CPU/Manufacturer/OS triple.
1022 <term>alpha-dec-{osf,linux,freebsd,openbsd,netbsd}:</term>
1023 <indexterm><primary>alpha-dec-osf</primary></indexterm>
1024 <indexterm><primary>alpha-dec-linux</primary></indexterm>
1025 <indexterm><primary>alpha-dec-freebsd</primary></indexterm>
1026 <indexterm><primary>alpha-dec-openbsd</primary></indexterm>
1027 <indexterm><primary>alpha-dec-netbsd</primary></indexterm>
1030 <para>The OSF port is currently working (as of GHC version
1031 5.02.1) and well supported. The native code generator is
1032 currently non-working. Other operating systems will
1033 require some minor porting.</para>
1038 <term>sparc-sun-sunos4</term>
1039 <indexterm><primary>sparc-sun-sunos4</primary></indexterm>
1041 <para>Probably works with minor tweaks, hasn't been tested
1047 <term>sparc-sun-solaris2</term>
1048 <indexterm><primary>sparc-sun-solaris2</primary></indexterm>
1050 <para>Fully supported, including native-code
1056 <term>hppa1.1-hp-hpux (HP-PA boxes running HPUX 9.x)</term>
1057 <indexterm><primary>hppa1.1-hp-hpux</primary></indexterm>
1059 <para>Works registerised. No native-code
1065 <term>i386-unknown-linux (PCs running Linux, ELF binary format)</term>
1066 <indexterm><primary>i386-*-linux</primary></indexterm>
1068 <para>GHC works registerised and has a native code
1069 generator. You <Emphasis>must</Emphasis> have GCC 2.7.x
1070 or later. NOTE about <literal>glibc</literal> versions:
1071 GHC binaries built on a system running <literal>glibc
1072 2.0</literal> won't work on a system running
1073 <literal>glibc 2.1</literal>, and vice versa. In general,
1074 don't expect compatibility between
1075 <literal>glibc</literal> versions, even if the shared
1076 library version hasn't changed.</para>
1081 <term>i386-unknown-freebsd (PCs running FreeBSD 2.2
1083 <indexterm><primary>i386-unknown-freebsd</primary></indexterm>
1085 <para>GHC works registerised. Pre-built packages are
1086 available in the native package format, so if you just
1087 need binaries you're better off just installing the
1093 <term>i386-unknown-{netbsd,openbsd) (PCs running NetBSD
1095 <indexterm><primary>i386-unknown-netbsd</primary></indexterm>
1096 <indexterm><primary>i386-unknown-openbsd</primary></indexterm>
1098 <para>Will require some minor porting effort, but should
1099 work registerised.</para>
1104 <term>i386-unknown-mingw32:</term>
1105 <indexterm><primary>i386-unknown-mingw32</primary></indexterm>
1107 <para>Fully supported under Win9x, WinNT, Win2k, and
1108 WinXP. Includes a native code generator. Building from
1109 source requires a recent <Literal>cygwin32</Literal>
1110 distribution to be installed.</para>
1115 <term>mips-sgi-irix5</term>
1116 <indexterm><primary>mips-sgi-irix[5-6]</primary></indexterm>
1118 <para>Port currently doesn't work, needs some minimal
1119 porting effort. As usual, we don't have access to
1120 machines and there hasn't been an overwhelming demand for
1121 this port, but feel free to get in touch.</para>
1126 <term>powerpc-ibm-aix</term>
1127 <indexterm><primary>powerpc-ibm-aix</primary></indexterm>
1129 <para>Port currently doesn't work, needs some minimal
1130 porting effort. As usual, we don't have access to
1131 machines and there hasn't been an overwhelming demand for
1132 this port, but feel free to get in touch.</para>
1137 <term>powerpc-apple-darwin</term>
1138 <indexterm><primary>powerpc-apple-darwin</primary></indexterm>
1140 <para>Works, unregisterised only at the moment.</para>
1145 <para>Various other systems have had GHC ported to them in the
1146 distant past, including various Motorola 68k boxes. The 68k
1147 support still remains, but porting to one of these systems will
1148 certainly be a non-trivial task.</para>
1152 <title>What machines the other tools run on</title>
1154 <para>Unless you hear otherwise, the other tools work if GHC
1160 <Sect1 id="sec-pre-supposed">
1161 <Title>Installing pre-supposed utilities
1163 <indexterm><primary>pre-supposed utilities</primary></indexterm>
1164 <indexterm><primary>utilities, pre-supposed</primary></indexterm></Title>
1167 Here are the gory details about some utility programs you may need;
1168 <Command>perl</Command>, <Command>gcc</Command> and
1169 <command>happy</command> are the only important
1170 ones. (PVM<indexterm><primary>PVM</primary></indexterm> is important
1171 if you're going for Parallel Haskell.) The
1172 <Command>configure</Command><indexterm><primary>configure</primary></indexterm>
1173 script will tell you if you are missing something.
1181 <indexterm><primary>pre-supposed: Perl</primary></indexterm>
1182 <indexterm><primary>Perl, pre-supposed</primary></indexterm>
1185 <Emphasis>You have to have Perl to proceed!</Emphasis>
1186 It is pretty easy to install.
1190 Perl 5 is required. For Win32 platforms, you should use the binary
1191 supplied in the InstallShield (copy it to <filename>/bin</filename>).
1192 The Cygwin-supplied Perl seems not to work.
1196 Perl should be put somewhere so that it can be invoked by the
1197 <Literal>#!</Literal> script-invoking mechanism. The full
1198 pathname may need to be less than 32 characters long on some
1202 </listitem></VarListEntry>
1204 <term>GNU C (<Command>gcc</Command>):</term>
1205 <indexterm><primary>pre-supposed: GCC (GNU C compiler)</primary></indexterm>
1206 <indexterm><primary>GCC (GNU C compiler), pre-supposed</primary></indexterm>
1210 We recommend using GCC version 2.95.2 on all platforms. Failing that,
1211 version 2.7.2 is stable on most platforms. Earlier versions of GCC
1212 can be assumed not to work, and versions in between 2.7.2 and 2.95.2
1213 (including <command>egcs</command>) have varying degrees of stability
1214 depending on the platform.
1218 If your GCC dies with ``internal error'' on some GHC source file,
1219 please let us know, so we can report it and get things improved.
1220 (Exception: on iX86 boxes—you may need to fiddle with GHC's
1221 <Option>-monly-N-regs</Option> option; see the User's Guide)
1223 </listitem></VarListEntry>
1227 <indexterm><primary>Happy</primary></indexterm>
1229 <para>Happy is a parser generator tool for Haskell, and is used to
1230 generate GHC's parsers. Happy is written in Haskell, and is a project
1231 in the CVS repository (<literal>fptools/happy</literal>). It can be
1232 built from source, but bear in mind that you'll need GHC installed in
1233 order to build it. To avoid the chicken/egg problem, install a binary
1234 distribtion of either Happy or GHC to get started. Happy
1235 distributions are available from <ulink
1236 url="http://www.haskell.org/happy/">Happy's Web Page</ulink>.
1242 <term>Autoconf:</term>
1243 <indexterm><primary>pre-supposed: Autoconf</primary></indexterm>
1244 <indexterm><primary>Autoconf, pre-supposed</primary></indexterm>
1247 GNU Autoconf is needed if you intend to build from the CVS sources, it
1248 is <Emphasis>not</Emphasis> needed if you just intend to build a
1249 standard source distribution.
1253 Autoconf builds the <Command>configure</Command> script from
1254 <Filename>configure.in</Filename> and <Filename>aclocal.m4</Filename>.
1255 If you modify either of these files, you'll need
1256 <command>autoconf</command> to rebuild <Filename>configure</Filename>.
1259 </listitem></VarListEntry>
1261 <term><Command>sed</Command></term>
1262 <indexterm><primary>pre-supposed: sed</primary></indexterm>
1263 <indexterm><primary>sed, pre-supposed</primary></indexterm>
1266 You need a working <Command>sed</Command> if you are going to build
1267 from sources. The build-configuration stuff needs it. GNU sed
1268 version 2.0.4 is no good! It has a bug in it that is tickled by the
1269 build-configuration. 2.0.5 is OK. Others are probably OK too
1270 (assuming we don't create too elaborate configure scripts.)
1272 </listitem></VarListEntry>
1277 One <Literal>fptools</Literal> project is worth a quick note at this
1278 point, because it is useful for all the others:
1279 <Literal>glafp-utils</Literal> contains several utilities which aren't
1280 particularly Glasgow-ish, but Occasionally Indispensable. Like
1281 <Command>lndir</Command> for creating symbolic link trees.
1284 <Sect2 id="pre-supposed-gph-tools">
1285 <Title>Tools for building parallel GHC (GPH)
1292 <term>PVM version 3:</term>
1293 <indexterm><primary>pre-supposed: PVM3 (Parallel Virtual Machine)</primary></indexterm>
1294 <indexterm><primary>PVM3 (Parallel Virtual Machine), pre-supposed</primary></indexterm>
1298 PVM is the Parallel Virtual Machine on which Parallel Haskell programs
1299 run. (You only need this if you plan to run Parallel Haskell.
1300 Concurent Haskell, which runs concurrent threads on a uniprocessor
1301 doesn't need it.) Underneath PVM, you can have (for example) a
1302 network of workstations (slow) or a multiprocessor box (faster).
1306 The current version of PVM is 3.3.11; we use 3.3.7. It is readily
1307 available on the net; I think I got it from
1308 <Literal>research.att.com</Literal>, in <Filename>netlib</Filename>.
1312 A PVM installation is slightly quirky, but easy to do. Just follow
1313 the <Filename>Readme</Filename> instructions.
1315 </listitem></VarListEntry>
1317 <term><Command>bash</Command>:</term>
1318 <indexterm><primary>bash, presupposed (Parallel Haskell only)</primary></indexterm>
1321 Sadly, the <Command>gr2ps</Command> script, used to convert ``parallelism profiles''
1322 to PostScript, is written in Bash (GNU's Bourne Again shell).
1323 This bug will be fixed (someday).
1325 </listitem></VarListEntry>
1331 <Sect2 id="pre-supposed-doc-tools">
1332 <Title>Tools for building the Documentation
1336 The following additional tools are required if you want to format the
1337 documentation that comes with the <Literal>fptools</Literal> projects:
1344 <term>DocBook:</term>
1345 <indexterm><primary>pre-supposed: DocBook</primary></indexterm>
1346 <indexterm><primary>DocBook, pre-supposed</primary></indexterm>
1349 All our documentation is written in SGML, using the DocBook DTD.
1350 Instructions on installing and configuring the DocBook tools are in the
1351 installation guide (in the GHC user guide).
1354 </listitem></VarListEntry>
1357 <indexterm><primary>pre-supposed: TeX</primary></indexterm>
1358 <indexterm><primary>TeX, pre-supposed</primary></indexterm>
1361 A decent TeX distribution is required if you want to produce printable
1362 documentation. We recomment teTeX, which includes just about
1363 everything you need.
1365 </listitem></VarListEntry>
1370 In order to actually build any documentation, you need to set
1371 <constant>SGMLDocWays</constant> in your
1372 <filename>build.mk</filename>. Valid values to add to this
1373 list are: <literal>dvi</literal>, <literal>ps</literal>,
1374 <literal>pdf</literal>, <literal>html</literal>, and
1375 <literal>rtf</literal>.
1380 <Sect2 id="pre-supposed-other-tools">
1381 <Title>Other useful tools
1387 <indexterm><primary>pre-supposed: flex</primary></indexterm>
1388 <indexterm><primary>flex, pre-supposed</primary></indexterm>
1392 This is a quite-a-bit-better-than-Lex lexer. Used to build a couple
1393 of utilities in <Literal>glafp-utils</Literal>. Depending on your
1394 operating system, the supplied <Command>lex</Command> may or may not
1395 work; you should get the GNU version.
1397 </listitem></VarListEntry>
1404 <Sect1 id="sec-building-from-source">
1405 <Title>Building from source
1407 <indexterm><primary>Building from source</primary></indexterm>
1408 <indexterm><primary>Source, building from</primary></indexterm></Title>
1411 You've been rash enough to want to build some of
1412 the Glasgow Functional Programming tools (GHC, Happy,
1413 nofib, etc.) from source. You've slurped the source,
1414 from the CVS repository or from a source distribution, and
1415 now you're sitting looking at a huge mound of bits, wondering
1420 Gingerly, you type <Command>make</Command>. Wrong already!
1424 This rest of this guide is intended for duffers like me, who aren't
1425 really interested in Makefiles and systems configurations, but who
1426 need a mental model of the interlocking pieces so that they can make
1427 them work, extend them consistently when adding new software, and lay
1428 hands on them gently when they don't work.
1431 <Sect2 id="sec-source-tree">
1432 <Title>Your source tree
1436 The source code is held in your <Emphasis>source tree</Emphasis>.
1437 The root directory of your source tree <Emphasis>must</Emphasis>
1438 contain the following directories and files:
1447 <Filename>Makefile</Filename>: the root Makefile.
1453 <Filename>mk/</Filename>: the directory that contains the
1454 main Makefile code, shared by all the
1455 <Literal>fptools</Literal> software.
1461 <Filename>configure.in</Filename>, <Filename>config.sub</Filename>, <Filename>config.guess</Filename>:
1462 these files support the configuration process.
1468 <Filename>install-sh</Filename>.
1477 All the other directories are individual <Emphasis>projects</Emphasis> of the
1478 <Literal>fptools</Literal> system—for example, the Glasgow Haskell Compiler
1479 (<Literal>ghc</Literal>), the Happy parser generator (<Literal>happy</Literal>), the <Literal>nofib</Literal> benchmark
1480 suite, and so on. You can have zero or more of these. Needless to
1481 say, some of them are needed to build others.
1485 The important thing to remember is that even if you want only one
1486 project (<Literal>happy</Literal>, say), you must have a source tree whose root
1487 directory contains <Filename>Makefile</Filename>, <Filename>mk/</Filename>, <Filename>configure.in</Filename>, and the
1488 project(s) you want (<Filename>happy/</Filename> in this case). You cannot get by with
1489 just the <Filename>happy/</Filename> directory.
1496 <indexterm><primary>build trees</primary></indexterm>
1497 <indexterm><primary>link trees, for building</primary></indexterm></Title>
1500 While you can build a system in the source tree, we don't recommend it.
1501 We often want to build multiple versions of our software
1502 for different architectures, or with different options (e.g. profiling).
1503 It's very desirable to share a single copy of the source code among
1508 So for every source tree we have zero or more <Emphasis>build trees</Emphasis>. Each
1509 build tree is initially an exact copy of the source tree, except that
1510 each file is a symbolic link to the source file, rather than being a
1511 copy of the source file. There are ``standard'' Unix utilities that
1512 make such copies, so standard that they go by different names:
1513 <Command>lndir</Command><indexterm><primary>lndir</primary></indexterm>, <Command>mkshadowdir</Command><indexterm><primary>mkshadowdir</primary></indexterm> are two (If you
1514 don't have either, the source distribution includes sources for the
1515 X11 <Command>lndir</Command>—check out <Filename>fptools/glafp-utils/lndir</Filename>). See <Xref LinkEnd="sec-storysofar"> for a typical invocation.
1519 The build tree does not need to be anywhere near the source tree in
1520 the file system. Indeed, one advantage of separating the build tree
1521 from the source is that the build tree can be placed in a
1522 non-backed-up partition, saving your systems support people from
1523 backing up untold megabytes of easily-regenerated, and
1524 rapidly-changing, gubbins. The golden rule is that (with a single
1525 exception—<XRef LinkEnd="sec-build-config">)
1526 <Emphasis>absolutely everything in the build tree is either a symbolic
1527 link to the source tree, or else is mechanically generated</Emphasis>.
1528 It should be perfectly OK for your build tree to vanish overnight; an
1529 hour or two compiling and you're on the road again.
1533 You need to be a bit careful, though, that any new files you create
1534 (if you do any development work) are in the source tree, not a build tree!
1538 Remember, that the source files in the build tree are <Emphasis>symbolic
1539 links</Emphasis> to the files in the source tree. (The build tree soon
1540 accumulates lots of built files like <Filename>Foo.o</Filename>, as well.) You
1541 can <Emphasis>delete</Emphasis> a source file from the build tree without affecting
1542 the source tree (though it's an odd thing to do). On the other hand,
1543 if you <Emphasis>edit</Emphasis> a source file from the build tree, you'll edit the
1544 source-tree file directly. (You can set up Emacs so that if you edit
1545 a source file from the build tree, Emacs will silently create an
1546 edited copy of the source file in the build tree, leaving the source
1547 file unchanged; but the danger is that you think you've edited the
1548 source file whereas actually all you've done is edit the build-tree
1549 copy. More commonly you do want to edit the source file.)
1553 Like the source tree, the top level of your build tree must be (a
1554 linked copy of) the root directory of the <Literal>fptools</Literal> suite. Inside
1555 Makefiles, the root of your build tree is called
1556 <constant>$(FPTOOLS_TOP)</constant><indexterm><primary>FPTOOLS_TOP</primary></indexterm>. In the rest of this document path
1557 names are relative to <constant>$(FPTOOLS_TOP)</constant> unless otherwise stated. For
1558 example, the file <Filename>ghc/mk/target.mk</Filename> is actually
1559 <Filename><constant>$(FPTOOLS_TOP)</constant>/ghc/mk/target.mk</Filename>.
1564 <Sect2 id="sec-build-config">
1565 <Title>Getting the build you want
1569 When you build <Literal>fptools</Literal> you will be compiling code on a particular
1570 <Emphasis>host platform</Emphasis>, to run on a particular <Emphasis>target platform</Emphasis>
1571 (usually the same as the host platform)<indexterm><primary>platform</primary></indexterm>. The
1572 difficulty is that there are minor differences between different
1573 platforms; minor, but enough that the code needs to be a bit different
1574 for each. There are some big differences too: for a different
1575 architecture we need to build GHC with a different native-code
1580 There are also knobs you can turn to control how the <Literal>fptools</Literal>
1581 software is built. For example, you might want to build GHC optimised
1582 (so that it runs fast) or unoptimised (so that you can compile it fast
1583 after you've modified it. Or, you might want to compile it with
1584 debugging on (so that extra consistency-checking code gets included)
1589 All of this stuff is called the <Emphasis>configuration</Emphasis> of your build.
1590 You set the configuration using a three-step process.
1594 <term>Step 1: get ready for configuration.</term>
1596 <para>Change directory to
1597 <constant>$(FPTOOLS_TOP)</constant> and
1599 <Command>autoconf</Command><indexterm><primary>autoconf</primary></indexterm>
1600 (with no arguments). This GNU program converts
1601 <Filename><constant>$(FPTOOLS_TOP)</constant>/configure.in</Filename>
1602 to a shell script called
1603 <Filename><constant>$(FPTOOLS_TOP)</constant>/configure</Filename>.
1606 <para>Some projects, including GHC, have their own
1607 configure script. If there's an
1608 <constant>$(FPTOOLS_TOP)/<project>/configure.in</constant>,
1609 then you need to run <command>autoconf</command> in that
1610 directory too.</para>
1612 <para>Both these steps are completely
1613 platform-independent; they just mean that the
1614 human-written file (<Filename>configure.in</Filename>)
1615 can be short, although the resulting shell script,
1616 <Command>configure</Command>, and
1617 <Filename>mk/config.h.in</Filename>, are long.</para>
1619 <para>In case you don't have <Command>autoconf</Command>
1620 we distribute the results, <Command>configure</Command>,
1621 and <Filename>mk/config.h.in</Filename>, with the source
1622 distribution. They aren't kept in the repository,
1628 <term>Step 2: system configuration.</term>
1630 <para>Runs the newly-created
1631 <Command>configure</Command> script, thus:</para>
1634 ./configure <optional><parameter>args</parameter></optional>
1637 <para><Command>configure</Command>'s mission is to
1638 scurry round your computer working out what architecture
1639 it has, what operating system, whether it has the
1640 <Function>vfork</Function> system call, where
1641 <Command>yacc</Command> is kept, whether
1642 <Command>gcc</Command> is available, where various
1643 obscure <Literal>#include</Literal> files are,
1644 whether it's a leap year, and what the systems manager
1645 had for lunch. It communicates these snippets of
1646 information in two ways:</para>
1652 <Filename>mk/config.mk.in</Filename><indexterm><primary>config.mk.in</primary></indexterm>
1654 <Filename>mk/config.mk</Filename><indexterm><primary>config.mk</primary></indexterm>,
1655 substituting for things between
1656 ``<Literal>@</Literal>'' brackets. So,
1657 ``<Literal>@HaveGcc@</Literal>'' will be replaced by
1658 ``<Literal>YES</Literal>'' or
1659 ``<Literal>NO</Literal>'' depending on what
1660 <Command>configure</Command> finds.
1661 <Filename>mk/config.mk</Filename> is included by
1662 every Makefile (directly or indirectly), so the
1663 configuration information is thereby communicated to
1664 all Makefiles.</para>
1668 <para> It translates
1669 <Filename>mk/config.h.in</Filename><indexterm><primary>config.h.in</primary></indexterm>
1671 <Filename>mk/config.h</Filename><indexterm><primary>config.h</primary></indexterm>.
1672 The latter is <Literal>#include</Literal>d by
1673 various C programs, which can thereby make use of
1674 configuration information.</para>
1678 <para><command>configure</command> takes some optional
1679 arguments. Use <literal>./configure --help</literal> to
1680 get a list of the available arguments. Here are some of
1681 the ones you might need:</para>
1685 <term><literal>--with-ghc=<parameter>path</parameter></literal></term>
1686 <indexterm><primary><literal>--with-ghc</literal></primary>
1689 <para>Specifies the path to an installed GHC which
1690 you would like to use. This compiler will be used
1691 for compiling GHC-specific code (eg. GHC itself).
1692 This option <emphasis>cannot</emphasis> be
1693 specified using <filename>build.mk</filename> (see
1694 later), because <command>configure</command> needs
1695 to auto-detect the version of GHC you're using.
1696 The default is to look for a compiler named
1697 <literal>ghc</literal> in your path.</para>
1702 <term><literal>--with-hc=<parameter>path</parameter></literal></term>
1703 <indexterm><primary><literal>--with-hc</literal></primary>
1706 <para>Specifies the path to any installed Haskell
1707 compiler. This compiler will be used for
1708 compiling generic Haskell code. The default is to
1709 use <literal>ghc</literal>.</para>
1714 <term><literal>--with-gcc=<parameter>path</parameter></literal></term>
1715 <indexterm><primary><literal>--with-gcc</literal></primary>
1718 <para>Specifies the path to the installed
1719 GCC. This compiler will be used to compile all C
1720 files, <emphasis>except</emphasis> any generated
1721 by the installed Haskell compiler, which will have
1722 its own idea of which C compiler (if any) to use.
1723 The default is to use <literal>gcc</literal>.</para>
1728 <para><command>configure</command> caches the results of
1729 its run in <Filename>config.cache</Filename>. Quite
1730 often you don't want that; you're running
1731 <Command>configure</Command> a second time because
1732 something has changed. In that case, simply delete
1733 <Filename>config.cache</Filename>.</para>
1738 <term>Step 3: build configuration.</term>
1741 Next, you say how this build of <Literal>fptools</Literal> is to differ from the
1742 standard defaults by creating a new file <Filename>mk/build.mk</Filename><indexterm><primary>build.mk</primary></indexterm>
1743 <Emphasis>in the build tree</Emphasis>. This file is the one and only file you edit
1744 in the build tree, precisely because it says how this build differs
1745 from the source. (Just in case your build tree does die, you might
1746 want to keep a private directory of <Filename>build.mk</Filename> files, and use a
1747 symbolic link in each build tree to point to the appropriate one.) So
1748 <Filename>mk/build.mk</Filename> never exists in the source tree—you create one in
1749 each build tree from the template. We'll discuss what to put in it
1752 </listitem></VarListEntry>
1757 And that's it for configuration. Simple, eh?
1760 <para>What do you put in your build-specific configuration file
1761 <filename>mk/build.mk</filename>? <Emphasis>For almost all
1762 purposes all you will do is put make variable definitions that
1763 override those in</Emphasis>
1764 <filename>mk/config.mk.in</filename>. The whole point of
1765 <filename>mk/config.mk.in</filename>—and its derived
1766 counterpart <filename>mk/config.mk</filename>—is to define
1767 the build configuration. It is heavily commented, as you will
1768 see if you look at it. So generally, what you do is look at
1769 <filename>mk/config.mk.in</filename>, and add definitions in
1770 <filename>mk/build.mk</filename> that override any of the
1771 <filename>config.mk</filename> definitions that you want to
1772 change. (The override occurs because the main boilerplate file,
1773 <filename>mk/boilerplate.mk</filename><indexterm><primary>boilerplate.mk</primary></indexterm>,
1774 includes <filename>build.mk</filename> after
1775 <filename>config.mk</filename>.)</para>
1777 <para>For example, <filename>config.mk.in</filename> contains
1778 the definition:</para>
1781 GhcHcOpts=-O -Rghc-timing
1784 <para>The accompanying comment explains that this is the list of
1785 flags passed to GHC when building GHC itself. For doing
1786 development, it is wise to add <literal>-DDEBUG</literal>, to
1787 enable debugging code. So you would add the following to
1788 <filename>build.mk</filename>:</para>
1790 <para>or, if you prefer,</para>
1793 GhcHcOpts += -DDEBUG
1796 <para>GNU <Command>make</Command> allows existing definitions to
1797 have new text appended using the ``<Literal>+=</Literal>''
1798 operator, which is quite a convenient feature.)</para>
1800 <para>If you want to remove the <literal>-O</literal> as well (a
1801 good idea when developing, because the turn-around cycle gets a
1802 lot quicker), you can just override
1803 <literal>GhcLibHcOpts</literal> altogether:</para>
1806 GhcHcOpts=-DDEBUG -Rghc-timing
1809 <para>When reading <filename>config.mk.in</filename>, remember
1810 that anything between ``@...@'' signs is going to be substituted
1811 by <Command>configure</Command> later. You
1812 <Emphasis>can</Emphasis> override the resulting definition if
1813 you want, but you need to be a bit surer what you are doing.
1814 For example, there's a line that says:</para>
1820 <para>This defines the Make variables <constant>YACC</constant>
1821 to the pathname for a <Command>yacc</Command> that
1822 <Command>configure</Command> finds somewhere. If you have your
1823 own pet <Command>yacc</Command> you want to use instead, that's
1824 fine. Just add this line to <filename>mk/build.mk</filename>:</para>
1830 <para>You do not <Emphasis>have</Emphasis> to have a
1831 <filename>mk/build.mk</filename> file at all; if you don't,
1832 you'll get all the default settings from
1833 <filename>mk/config.mk.in</filename>.</para>
1835 <para>You can also use <filename>build.mk</filename> to override
1836 anything that <Command>configure</Command> got wrong. One place
1837 where this happens often is with the definition of
1838 <constant>FPTOOLS_TOP_ABS</constant>: this
1839 variable is supposed to be the canonical path to the top of your
1840 source tree, but if your system uses an automounter then the
1841 correct directory is hard to find automatically. If you find
1842 that <Command>configure</Command> has got it wrong, just put the
1843 correct definition in <filename>build.mk</filename>.</para>
1847 <sect2 id="sec-storysofar">
1848 <title>The story so far</title>
1850 <para>Let's summarise the steps you need to carry to get
1851 yourself a fully-configured build tree from scratch.</para>
1855 <para> Get your source tree from somewhere (CVS repository
1856 or source distribution). Say you call the root directory
1857 <filename>myfptools</filename> (it does not have to be
1858 called <filename>fptools</filename>). Make sure that you
1859 have the essential files (see <XRef
1860 LinkEnd="sec-source-tree">).</para>
1865 <para>(Optional) Use <Command>lndir</Command> or
1866 <Command>mkshadowdir</Command> to create a build tree.</para>
1870 $ mkshadowdir . /scratch/joe-bloggs/myfptools-sun4
1873 <para>(N.B. <Command>mkshadowdir</Command>'s first argument
1874 is taken relative to its second.) You probably want to give
1875 the build tree a name that suggests its main defining
1876 characteristic (in your mind at least), in case you later
1881 <para>Change directory to the build tree. Everything is
1882 going to happen there now.</para>
1885 $ cd /scratch/joe-bloggs/myfptools-sun4
1891 <para>Prepare for system configuration:</para>
1897 <para>(You can skip this step if you are starting from a
1898 source distribution, and you already have
1899 <filename>configure</filename> and
1900 <filename>mk/config.h.in</filename>.)</para>
1902 <para>Some projects, including GHC itself, have their own
1903 configure scripts, so it is necessary to run autoconf again
1904 in the appropriate subdirectories. eg:</para>
1907 $ (cd ghc; autoconf)
1912 <para>Do system configuration:</para>
1918 <para>Don't forget to check whether you need to add any
1919 arguments to <literal>configure</literal>; for example, a
1920 common requirement is to specify which GHC to use with
1921 <option>--with-ghc=<replaceable>ghc</replaceable></option>.</para>
1925 <para>Create the file <filename>mk/build.mk</filename>,
1926 adding definitions for your desired configuration
1935 <para>You can make subsequent changes to
1936 <filename>mk/build.mk</filename> as often as you like. You do
1937 not have to run any further configuration programs to make these
1938 changes take effect. In theory you should, however, say
1939 <Command>gmake clean</Command>, <Command>gmake all</Command>,
1940 because configuration option changes could affect
1941 anything—but in practice you are likely to know what's
1946 <Title>Making things</Title>
1948 <para>At this point you have made yourself a fully-configured
1949 build tree, so you are ready to start building real
1952 <para>The first thing you need to know is that <Emphasis>you
1953 must use GNU <Command>make</Command>, usually called
1954 <Command>gmake</Command>, not standard Unix
1955 <Command>make</Command></Emphasis>. If you use standard Unix
1956 <Command>make</Command> you will get all sorts of error messages
1957 (but no damage) because the <Literal>fptools</Literal>
1958 <Command>Makefiles</Command> use GNU <Command>make</Command>'s
1959 facilities extensively.</para>
1961 <para>To just build the whole thing, <command>cd</command> to
1962 the top of your <literal>fptools</literal> tree and type
1963 <command>gmake</command>. This will prepare the tree and build
1964 the various projects in the correct order.</para>
1968 <Sect2 id="sec-standard-targets">
1969 <Title>Standard Targets</title>
1970 <indexterm><primary>targets, standard makefile</primary></indexterm>
1971 <indexterm><primary>makefile targets</primary></indexterm>
1973 <para>In any directory you should be able to make the following:
1978 <term><Literal>boot</Literal>:</term>
1980 <para>does the one-off preparation required to get ready for the real
1981 work. Notably, it does <Command>gmake depend</Command> in all
1982 directories that contain programs. It also builds the necessary tools
1983 for compilation to proceed.</para>
1985 <para>Invoking the <literal>boot</literal> target explicitly is not
1986 normally necessary. From the top-level <literal>fptools</literal>
1987 directory, invoking <literal>gmake</literal> causes <literal>gmake
1988 boot all</literal> to be invoked in each of the project
1989 subdirectories, in the order specified by
1990 <literal>$(AllTargets)</literal> in
1991 <literal>config.mk</literal>.</para>
1993 <para>If you're working in a subdirectory somewhere and need to update
1994 the dependencies, <literal>gmake boot</literal> is a good way to do it.</para>
1996 </listitem></VarListEntry>
1998 <term><Literal>all</Literal>:</term>
2001 makes all the final target(s) for this Makefile.
2002 Depending on which directory you are in a ``final target'' may be an
2003 executable program, a library archive, a shell script, or a Postscript
2004 file. Typing <Command>gmake</Command> alone is generally the same as typing <Command>gmake all</Command>.
2006 </listitem></VarListEntry>
2008 <term><Literal>install</Literal>:</term>
2011 installs the things built by <Literal>all</Literal> (except for the documentation). Where does it
2012 install them? That is specified by
2013 <filename>mk/config.mk.in</filename>; you can override it in
2014 <filename>mk/build.mk</filename>, or by running
2015 <command>configure</command> with command-line arguments like
2016 <literal>--bindir=/home/simonpj/bin</literal>; see <literal>./configure
2017 --help</literal> for the full details.
2019 </listitem></VarListEntry>
2021 <term><Literal>install-docs</Literal>:</term>
2024 installs the documentation. Otherwise behaves just like <literal>install</literal>.
2026 </listitem></VarListEntry>
2028 <term><Literal>uninstall</Literal>:</term>
2031 reverses the effect of <Literal>install</Literal>.
2033 </listitem></VarListEntry>
2036 <term><Literal>clean</Literal>:</term>
2039 Delete all files from the current directory that are normally created
2040 by building the program. Don't delete the files that record the
2041 configuration, or files generated by <Command>gmake boot</Command>.
2042 Also preserve files that could be made by building, but normally
2043 aren't because the distribution comes with them.</para>
2044 </listitem></VarListEntry>
2047 <term><literal>distclean</literal>:</term>
2049 <para>Delete all files from the current directory that are created by
2050 configuring or building the program. If you have unpacked the source
2051 and built the program without creating any other files, <literal>make
2052 distclean</literal> should leave only the files that were in the
2053 distribution.</para>
2058 <term><literal>mostlyclean</literal>:</term>
2060 <para>Like <literal>clean</literal>, but may refrain from deleting a
2061 few files that people normally don't want to recompile.</para>
2066 <term><Literal>maintainer-clean</Literal>:</term>
2069 Delete everything from the current directory that can be reconstructed
2070 with this Makefile. This typically includes everything deleted by
2071 <literal>distclean</literal>, plus more: C source files produced by
2072 Bison, tags tables, Info files, and so on.</para>
2074 <para>One exception, however: <literal>make maintainer-clean</literal>
2075 should not delete <filename>configure</filename> even if
2076 <filename>configure</filename> can be remade using a rule in the
2077 <filename>Makefile</filename>. More generally, <literal>make
2078 maintainer-clean</literal> should not delete anything that needs to
2079 exist in order to run <filename>configure</filename> and then begin to
2080 build the program.</para>
2085 <term><Literal>check</Literal>:</term>
2090 </listitem></VarListEntry>
2095 All of these standard targets automatically recurse into
2096 sub-directories. Certain other standard targets do not:
2103 <term><Literal>configure</Literal>:</term>
2106 is only available in the root directory
2107 <constant>$(FPTOOLS_TOP)</constant>; it has been discussed in <XRef LinkEnd="sec-build-config">.
2109 </listitem></VarListEntry>
2111 <term><Literal>depend</Literal>:</term>
2114 make a <filename>.depend</filename> file in each directory that needs
2115 it. This <filename>.depend</filename> file contains mechanically-generated dependency
2116 information; for example, suppose a directory contains a Haskell
2117 source module <filename>Foo.lhs</filename> which imports another module <Literal>Baz</Literal>.
2118 Then the generated <filename>.depend</filename> file will contain the dependency:
2130 which says that the object file <filename>Foo.o</filename> depends on the interface file
2131 <filename>Baz.hi</filename> generated by compiling module <Literal>Baz</Literal>. The <filename>.depend</filename> file is
2132 automatically included by every Makefile.
2134 </listitem></VarListEntry>
2136 <term><Literal>binary-dist</Literal>:</term>
2139 make a binary distribution. This is the
2140 target we use to build the binary distributions of GHC and Happy.
2142 </listitem></VarListEntry>
2144 <term><Literal>dist</Literal>:</term>
2147 make a source distribution. Note that this target does “make
2148 distclean” as part of its work; don't use it if you want to keep
2151 </listitem></VarListEntry>
2156 Most <filename>Makefile</filename>s have targets other than these. You can discover them by looking in the <filename>Makefile</filename> itself.
2162 <title>Using a project from the build tree</title>
2164 If you want to build GHC (say) and just use it direct from the build
2165 tree without doing <literal>make install</literal> first, you can run
2166 the in-place driver script:
2167 <filename>ghc/compiler/ghc-inplace</filename>.
2170 <para> Do <emphasis>NOT</emphasis> use
2171 <filename>ghc/compiler/ghc</filename>, or
2172 <filename>ghc/compiler/ghc-5.xx</filename>, as these are the scripts
2173 intended for installation, and contain hard-wired paths to the
2174 installed libraries, rather than the libraries in the build tree.
2178 Happy can similarly be run from the build tree, using
2179 <filename>happy/src/happy-inplace</filename>.
2184 <Title>Fast Making <indexterm><primary>fastmake</primary></indexterm>
2185 <indexterm><primary>dependencies, omitting</primary></indexterm>
2186 <indexterm><primary>FAST, makefile
2187 variable</primary></indexterm></Title>
2190 Sometimes the dependencies get in the way: if you've made a small
2191 change to one file, and you're absolutely sure that it won't affect
2192 anything else, but you know that <Command>make</Command> is going to rebuild everything
2193 anyway, the following hack may be useful:
2205 This tells the make system to ignore dependencies and just build what
2206 you tell it to. In other words, it's equivalent to temporarily
2207 removing the <filename>.depend</filename> file in the current directory (where
2208 <Command>mkdependHS</Command> and friends store their dependency information).
2212 A bit of history: GHC used to come with a <Command>fastmake</Command> script that did
2213 the above job, but GNU make provides the features we need to do it
2214 without resorting to a script. Also, we've found that fastmaking is
2215 less useful since the advent of GHC's recompilation checker (see the
2216 User's Guide section on "Separate Compilation").
2223 <Sect1 id="sec-makefile-arch">
2224 <Title>The <filename>Makefile</filename> architecture
2225 <indexterm><primary>makefile architecture</primary></indexterm></Title>
2228 <Command>make</Command> is great if everything works—you type <Command>gmake install</Command> and
2229 lo! the right things get compiled and installed in the right places.
2230 Our goal is to make this happen often, but somehow it often doesn't;
2231 instead some weird error message eventually emerges from the bowels of
2232 a directory you didn't know existed.
2236 The purpose of this section is to give you a road-map to help you figure
2237 out what is going right and what is going wrong.
2241 <title>Debugging</title>
2243 <para>Debugging <filename>Makefile</filename>s is something of a
2244 black art, but here's a couple of tricks that we find
2245 particularly useful. The following command allows you to see
2246 the contents of any make variable in the context of the current
2247 <filename>Makefile</filename>:</para>
2249 <screen>$ make show VALUE=HS_SRCS</screen>
2251 <para>where you can replace <literal>HS_SRCS</literal> with the
2252 name of any variable you wish to see the value of.</para>
2254 <para>GNU make has a <option>-d</option> option which generates
2255 a dump of the decision procedure used to arrive at a conclusion
2256 about which files should be recompiled. Sometimes useful for
2257 tracking down problems with superfluous or missing
2258 recompilations.</para>
2262 <Title>A small project</Title>
2265 To get started, let us look at the <filename>Makefile</filename> for an imaginary small
2266 <Literal>fptools</Literal> project, <Literal>small</Literal>. Each project in <Literal>fptools</Literal> has its own
2267 directory in <constant>FPTOOLS_TOP</constant>, so the <Literal>small</Literal> project will have its own
2268 directory <constant>FPOOLS_TOP/small/</constant>. Inside the <filename>small/</filename> directory there
2269 will be a <filename>Makefile</filename>, looking something like this:
2273 <indexterm><primary>Makefile, minimal</primary></indexterm>
2276 # Makefile for fptools project "small"
2279 include $(TOP)/mk/boilerplate.mk
2281 SRCS = $(wildcard *.lhs) $(wildcard *.c)
2284 include $(TOP)/target.mk
2290 This <filename>Makefile</filename> has three sections:
2299 The first section includes
2303 One of the most important
2304 features of GNU <Command>make</Command> that we use is the ability for a <filename>Makefile</filename> to
2305 include another named file, very like <Command>cpp</Command>'s <Literal>#include</Literal>
2310 a file of ``boilerplate'' code from the level
2311 above (which in this case will be
2312 <filename><constant>FPTOOLS_TOP</constant>/mk/boilerplate.mk</filename><indexterm><primary>boilerplate.mk</primary></indexterm>). As its name
2313 suggests, <filename>boilerplate.mk</filename> consists of a large quantity of standard
2314 <filename>Makefile</filename> code. We discuss this boilerplate in more detail in
2315 <XRef LinkEnd="sec-boiler">.
2316 <indexterm><primary>include, directive in Makefiles</primary></indexterm>
2317 <indexterm><primary>Makefile inclusion</primary></indexterm>
2319 Before the <Literal>include</Literal> statement, you must define the <Command>make</Command> variable
2320 <constant>TOP</constant><indexterm><primary>TOP</primary></indexterm> to be the directory containing the <filename>mk</filename> directory in
2321 which the <filename>boilerplate.mk</filename> file is. It is <Emphasis>not</Emphasis> OK to simply say
2325 include ../mk/boilerplate.mk # NO NO NO
2329 Why? Because the <filename>boilerplate.mk</filename> file needs to know where it is, so
2330 that it can, in turn, <Literal>include</Literal> other files. (Unfortunately, when an
2331 <Literal>include</Literal>d file does an <Literal>include</Literal>, the filename is treated relative to
2332 the directory in which <Command>gmake</Command> is being run, not the directory in
2333 which the <Literal>include</Literal>d sits.) In general, <Emphasis>every file <filename>foo.mk</filename>
2334 assumes that <filename><constant>$(TOP)</constant>/mk/foo.mk</filename> refers to itself.</Emphasis> It is up to the
2335 <filename>Makefile</filename> doing the <Literal>include</Literal> to ensure this is the case.
2337 Files intended for inclusion in other <filename>Makefile</filename>s are written to have
2338 the following property: <Emphasis>after <filename>foo.mk</filename> is <Literal>include</Literal>d, it leaves
2339 <constant>TOP</constant> containing the same value as it had just before the <Literal>include</Literal>
2340 statement</Emphasis>. In our example, this invariant guarantees that the
2341 <Literal>include</Literal> for <filename>target.mk</filename> will look in the same directory as that for
2342 <filename>boilerplate.mk</filename>.
2349 The second section defines the following standard <Command>make</Command>
2350 variables: <constant>SRCS</constant><indexterm><primary>SRCS</primary></indexterm> (the source files from which is to be
2351 built), and <constant>HS_PROG</constant><indexterm><primary>HS_PROG</primary></indexterm> (the executable binary to be
2352 built). We will discuss in more detail what the ``standard
2353 variables'' are, and how they affect what happens, in <XRef LinkEnd="sec-targets">.
2355 The definition for <constant>SRCS</constant> uses the useful GNU <Command>make</Command> construct
2356 <Literal>$(wildcard $pat$)</Literal><indexterm><primary>wildcard</primary></indexterm>, which expands to a list of all
2357 the files matching the pattern <Literal>pat</Literal> in the current directory. In
2358 this example, <constant>SRCS</constant> is set to the list of all the <filename>.lhs</filename> and <filename>.c</filename>
2359 files in the directory. (Let's suppose there is one of each,
2360 <filename>Foo.lhs</filename> and <filename>Baz.c</filename>.)
2367 The last section includes a second file of standard code,
2368 called <filename>target.mk</filename><indexterm><primary>target.mk</primary></indexterm>. It contains the rules that tell
2369 <Command>gmake</Command> how to make the standard targets (<Xref LinkEnd="sec-standard-targets">). Why, you ask,
2370 can't this standard code be part of <filename>boilerplate.mk</filename>? Good question.
2371 We discuss the reason later, in <Xref LinkEnd="sec-boiler-arch">.
2373 You do not <Emphasis>have</Emphasis> to <Literal>include</Literal> the <filename>target.mk</filename> file. Instead, you
2374 can write rules of your own for all the standard targets. Usually,
2375 though, you will find quite a big payoff from using the canned rules
2376 in <filename>target.mk</filename>; the price tag is that you have to understand what
2377 canned rules get enabled, and what they do (<Xref LinkEnd="sec-targets">).
2387 In our example <filename>Makefile</filename>, most of the work is done by the two
2388 <Literal>include</Literal>d files. When you say <Command>gmake all</Command>, the following things
2398 <Command>gmake</Command> figures out that the object files are <filename>Foo.o</filename> and
2399 <filename>Baz.o</filename>.
2406 It uses a boilerplate pattern rule to compile <filename>Foo.lhs</filename> to
2407 <filename>Foo.o</filename> using a Haskell compiler. (Which one? That is set in the
2408 build configuration.)
2415 It uses another standard pattern rule to compile <filename>Baz.c</filename> to
2416 <filename>Baz.o</filename>, using a C compiler. (Ditto.)
2423 It links the resulting <filename>.o</filename> files together to make <Literal>small</Literal>,
2424 using the Haskell compiler to do the link step. (Why not use <Command>ld</Command>?
2425 Because the Haskell compiler knows what standard libraries to link in.
2426 How did <Command>gmake</Command> know to use the Haskell compiler to do the link,
2427 rather than the C compiler? Because we set the variable <constant>HS_PROG</constant>
2428 rather than <constant>C_PROG</constant>.)
2438 All <filename>Makefile</filename>s should follow the above three-section format.
2444 <Title>A larger project</Title>
2447 Larger projects are usually structured into a number of sub-directories,
2448 each of which has its own <filename>Makefile</filename>. (In very large projects, this
2449 sub-structure might be iterated recursively, though that is rare.)
2450 To give you the idea, here's part of the directory structure for
2451 the (rather large) GHC project:
2464 ...source files for documentation...
2467 ...source files for driver...
2470 parser/...source files for parser...
2471 renamer/...source files for renamer...
2478 The sub-directories <filename>docs</filename>, <filename>driver</filename>, <filename>compiler</filename>, and so on, each
2479 contains a sub-component of GHC, and each has its own <filename>Makefile</filename>.
2480 There must also be a <filename>Makefile</filename> in <filename><constant>$(FPTOOLS_TOP)</constant>/ghc</filename>. It does most
2481 of its work by recursively invoking <Command>gmake</Command> on the <filename>Makefile</filename>s in the
2482 sub-directories. We say that <filename>ghc/Makefile</filename> is a <Emphasis>non-leaf
2483 <filename>Makefile</filename></Emphasis>, because it does little except organise its children,
2484 while the <filename>Makefile</filename>s in the sub-directories are all <Emphasis>leaf
2485 <filename>Makefile</filename>s</Emphasis>. (In principle the sub-directories might themselves
2486 contain a non-leaf <filename>Makefile</filename> and several sub-sub-directories, but
2487 that does not happen in GHC.)
2491 The <filename>Makefile</filename> in <filename>ghc/compiler</filename> is considered a leaf <filename>Makefile</filename> even
2492 though the <filename>ghc/compiler</filename> has sub-directories, because these sub-directories
2493 do not themselves have <filename>Makefile</filename>s in them. They are just used to structure
2494 the collection of modules that make up GHC, but all are managed by the
2495 single <filename>Makefile</filename> in <filename>ghc/compiler</filename>.
2499 You will notice that <filename>ghc/</filename> also contains a directory <filename>ghc/mk/</filename>. It
2500 contains GHC-specific <filename>Makefile</filename> boilerplate code. More precisely:
2509 <filename>ghc/mk/boilerplate.mk</filename> is included at the top of
2510 <filename>ghc/Makefile</filename>, and of all the leaf <filename>Makefile</filename>s in the
2511 sub-directories. It in turn <Literal>include</Literal>s the main boilerplate file
2512 <filename>mk/boilerplate.mk</filename>.
2520 <filename>ghc/mk/target.mk</filename> is <Literal>include</Literal>d at the bottom of
2521 <filename>ghc/Makefile</filename>, and of all the leaf <filename>Makefile</filename>s in the
2522 sub-directories. It in turn <Literal>include</Literal>s the file <filename>mk/target.mk</filename>.
2532 So these two files are the place to look for GHC-wide customisation
2533 of the standard boilerplate.
2538 <Sect2 id="sec-boiler-arch">
2539 <Title>Boilerplate architecture
2540 <indexterm><primary>boilerplate architecture</primary></indexterm>
2544 Every <filename>Makefile</filename> includes a <filename>boilerplate.mk</filename><indexterm><primary>boilerplate.mk</primary></indexterm> file
2545 at the top, and <filename>target.mk</filename><indexterm><primary>target.mk</primary></indexterm> file at the bottom. In
2546 this section we discuss what is in these files, and why there have to
2547 be two of them. In general:
2556 <filename>boilerplate.mk</filename> consists of:
2562 <Emphasis>Definitions of millions of <Command>make</Command> variables</Emphasis> that
2563 collectively specify the build configuration. Examples:
2564 <constant>HC_OPTS</constant><indexterm><primary>HC_OPTS</primary></indexterm>, the options to feed to the Haskell compiler;
2565 <constant>NoFibSubDirs</constant><indexterm><primary>NoFibSubDirs</primary></indexterm>, the sub-directories to enable within the
2566 <Literal>nofib</Literal> project; <constant>GhcWithHc</constant><indexterm><primary>GhcWithHc</primary></indexterm>, the name of the Haskell
2567 compiler to use when compiling GHC in the <Literal>ghc</Literal> project.
2573 <Emphasis>Standard pattern rules</Emphasis> that tell <Command>gmake</Command> how to construct one
2581 <filename>boilerplate.mk</filename> needs to be <Literal>include</Literal>d at the <Emphasis>top</Emphasis>
2582 of each <filename>Makefile</filename>, so that the user can replace the
2583 boilerplate definitions or pattern rules by simply giving a new
2584 definition or pattern rule in the <filename>Makefile</filename>. <Command>gmake</Command>
2585 simply takes the last definition as the definitive one.
2587 Instead of <Emphasis>replacing</Emphasis> boilerplate definitions, it is also quite
2588 common to <Emphasis>augment</Emphasis> them. For example, a <filename>Makefile</filename> might say:
2596 thereby adding ``<Option>-O</Option>'' to the end of <constant>SRC_HC_OPTS</constant><indexterm><primary>SRC_HC_OPTS</primary></indexterm>.
2603 <filename>target.mk</filename> contains <Command>make</Command> rules for the standard
2604 targets described in <Xref LinkEnd="sec-standard-targets">. These rules are selectively included,
2605 depending on the setting of certain <Command>make</Command> variables. These
2606 variables are usually set in the middle section of the
2607 <filename>Makefile</filename> between the two <Literal>include</Literal>s.
2609 <filename>target.mk</filename> must be included at the end (rather than being part of
2610 <filename>boilerplate.mk</filename>) for several tiresome reasons:
2617 <Command>gmake</Command> commits target and dependency lists earlier than
2618 it should. For example, <FIlename>target.mk</FIlename> has a rule that looks like
2623 $(HS_PROG) : $(OBJS)
2624 $(HC) $(LD_OPTS) $< -o $@
2628 If this rule was in <filename>boilerplate.mk</filename> then <constant>$(HS_PROG)</constant><indexterm><primary>HS_PROG</primary></indexterm>
2629 and <constant>$(OBJS)</constant><indexterm><primary>OBJS</primary></indexterm> would not have their final values at the
2630 moment <Command>gmake</Command> encountered the rule. Alas, <Command>gmake</Command> takes a snapshot
2631 of their current values, and wires that snapshot into the rule. (In
2632 contrast, the commands executed when the rule ``fires'' are only
2633 substituted at the moment of firing.) So, the rule must follow the
2634 definitions given in the <filename>Makefile</filename> itself.
2641 Unlike pattern rules, ordinary rules cannot be overriden or
2642 replaced by subsequent rules for the same target (at least, not without an
2643 error message). Including ordinary rules in <filename>boilerplate.mk</filename> would
2644 prevent the user from writing rules for specific targets in specific cases.
2651 There are a couple of other reasons I've forgotten, but it doesn't
2667 <Sect2 id="sec-boiler">
2668 <Title>The main <filename>mk/boilerplate.mk</filename> file
2670 <indexterm><primary>boilerplate.mk</primary></indexterm></Title>
2673 If you look at <filename><constant>$(FPTOOLS_TOP)</constant>/mk/boilerplate.mk</filename> you will find
2674 that it consists of the following sections, each held in a separate
2681 <term><filename>config.mk</filename></term>
2682 <indexterm><primary>config.mk</primary></indexterm>
2684 <para>is the build configuration file we discussed at
2685 length in <Xref LinkEnd="sec-build-config">.</para>
2690 <term><filename>paths.mk</filename></term>
2691 <indexterm><primary>paths.mk</primary></indexterm>
2693 <para>defines <Command>make</Command> variables for
2694 pathnames and file lists. This file contains code for
2695 automatically compiling lists of source files and deriving
2696 lists of object files from those. The results can be
2697 overriden in the <filename>Makefile</filename>, but in
2698 most cases the automatic setup should do the right
2701 <para>The following variables may be set in the
2702 <filename>Makefile</filename> to affect how the automatic
2703 source file search is done:</para>
2707 <term><literal>ALL_DIRS</literal></term>
2708 <indexterm><primary><literal>ALL_DIRS</literal></primary>
2711 <para>Set to a list of directories to search in
2712 addition to the current directory for source
2718 <term><literal>EXCLUDE_SRCS</literal></term>
2719 <indexterm><primary><literal>EXCLUDE_SRCS</literal></primary>
2722 <para>Set to a list of source files (relative to the
2723 current directory) to omit from the automatic
2724 search. The source searching machinery is clever
2725 enough to know that if you exclude a source file
2726 from which other sources are derived, then the
2727 derived sources should also be excluded. For
2728 example, if you set <literal>EXCLUDED_SRCS</literal>
2729 to include <filename>Foo.y</filename>, then
2730 <filename>Foo.hs</filename> will also be
2736 <term><literal>EXTRA_SRCS</literal></term>
2737 <indexterm><primary><literal>EXCLUDE_SRCS</literal></primary>
2740 <para>Set to a list of extra source files (perhaps
2741 in directories not listed in
2742 <literal>ALL_DIRS</literal>) that should be
2748 <para>The results of the automatic source file search are
2749 placed in the following make variables:</para>
2753 <term><literal>SRCS</literal></term>
2754 <indexterm><primary><literal>SRCS</literal></primary></indexterm>
2756 <para>All source files found, sorted and without
2757 duplicates, including those which might not exist
2758 yet but will be derived from other existing sources.
2759 <literal>SRCS</literal> <emphasis>can</emphasis> be
2760 overriden if necessary, in which case the variables
2761 below will follow suit.</para>
2766 <term><literal>HS_SRCS</literal></term>
2767 <indexterm><primary><literal>HS_SRCS</literal></primary></indexterm>
2769 <para>all Haskell source files in the current
2770 directory, including those derived from other source
2771 files (eg. Happy sources also give rise to Haskell
2777 <term><literal>HS_OBJS</literal></term>
2778 <indexterm><primary><literal>HS_OBJS</literal></primary></indexterm>
2780 <para>Object files derived from
2781 <literal>HS_SRCS</literal>.</para>
2786 <term><literal>HS_IFACES</literal></term>
2787 <indexterm><primary><literal>HS_IFACES</literal></primary></indexterm>
2789 <para>Interface files (<literal>.hi</literal> files)
2790 derived from <literal>HS_SRCS</literal>.</para>
2795 <term><literal>C_SRCS</literal></term>
2796 <indexterm><primary><literal>C_SRCS</literal></primary></indexterm>
2798 <para>All C source files found.</para>
2803 <term><literal>C_OBJS</literal></term>
2804 <indexterm><primary><literal>C_OBJS</literal></primary></indexterm>
2806 <para>Object files derived from
2807 <literal>C_SRCS</literal>.</para>
2812 <term><literal>SCRIPT_SRCS</literal></term>
2813 <indexterm><primary><literal>SCRIPT_SRCS</literal></primary></indexterm>
2815 <para>All script source files found
2816 (<literal>.lprl</literal> files).</para>
2821 <term><literal>SCRIPT_OBJS</literal></term>
2822 <indexterm><primary><literal>SCRIPT_OBJS</literal></primary></indexterm>
2824 <para><quote>object</quote> files derived from
2825 <literal>SCRIPT_SRCS</literal>
2826 (<literal>.prl</literal> files).</para>
2831 <term><literal>HSC_SRCS</literal></term>
2832 <indexterm><primary><literal>HSC_SRCS</literal></primary></indexterm>
2834 <para>All <literal>hsc2hs</literal> source files
2835 (<literal>.hsc</literal> files).</para>
2840 <term><literal>HAPPY_SRCS</literal></term>
2841 <indexterm><primary><literal>HAPPY_SRCS</literal></primary></indexterm>
2843 <para>All <literal>happy</literal> source files
2844 (<literal>.y</literal> or <literal>.hy</literal> files).</para>
2849 <term><literal>OBJS</literal></term>
2850 <indexterm><primary>OBJS</primary></indexterm>
2852 <para>the concatenation of
2853 <literal>$(HS_OBJS)</literal>,
2854 <literal>$(C_OBJS)</literal>, and
2855 <literal>$(SCRIPT_OBJS)</literal>.</para>
2860 <para>Any or all of these definitions can easily be
2861 overriden by giving new definitions in your
2862 <filename>Makefile</filename>.</para>
2864 <para>What, exactly, does <filename>paths.mk</filename>
2865 consider a <quote>source file</quote> to be? It's based
2866 on the file's suffix (e.g. <filename>.hs</filename>,
2867 <filename>.lhs</filename>, <filename>.c</filename>,
2868 <filename>.hy</filename>, etc), but this is the kind of
2869 detail that changes, so rather than enumerate the source
2870 suffices here the best thing to do is to look in
2871 <filename>paths.mk</filename>.</para>
2876 <term><filename>opts.mk</filename></term>
2877 <indexterm><primary>opts.mk</primary></indexterm>
2879 <para>defines <Command>make</Command> variables for option
2880 strings to pass to each program. For example, it defines
2881 <constant>HC_OPTS</constant><indexterm><primary>HC_OPTS</primary></indexterm>,
2882 the option strings to pass to the Haskell compiler. See
2883 <Xref LinkEnd="sec-suffix">.</para>
2888 <term><filename>suffix.mk</filename></term>
2889 <indexterm><primary>suffix.mk</primary></indexterm>
2891 <para>defines standard pattern rules—see <Xref
2892 LinkEnd="sec-suffix">.</para>
2898 Any of the variables and pattern rules defined by the boilerplate file
2899 can easily be overridden in any particular <filename>Makefile</filename>, because the
2900 boilerplate <Literal>include</Literal> comes first. Definitions after this <Literal>include</Literal>
2901 directive simply override the default ones in <filename>boilerplate.mk</filename>.
2906 <Sect2 id="sec-suffix">
2907 <Title>Pattern rules and options
2909 <indexterm><primary>Pattern rules</primary></indexterm></Title>
2912 The file <filename>suffix.mk</filename><indexterm><primary>suffix.mk</primary></indexterm> defines standard <Emphasis>pattern
2913 rules</Emphasis> that say how to build one kind of file from another, for
2914 example, how to build a <filename>.o</filename> file from a <filename>.c</filename> file. (GNU <Command>make</Command>'s
2915 <Emphasis>pattern rules</Emphasis> are more powerful and easier to use than Unix
2916 <Command>make</Command>'s <Emphasis>suffix rules</Emphasis>.)
2920 Almost all the rules look something like this:
2928 $(CC) $(CC_OPTS) -c $< -o $@
2934 Here's how to understand the rule. It says that
2935 <Emphasis>something</Emphasis><filename>.o</filename> (say <filename>Foo.o</filename>) can be built from
2936 <Emphasis>something</Emphasis><filename>.c</filename> (<filename>Foo.c</filename>), by invoking the C compiler
2937 (path name held in <constant>$(CC)</constant>), passing to it the options
2938 <constant>$(CC_OPTS)</constant> and the rule's dependent file of the rule
2939 <Literal>$<</Literal> (<filename>Foo.c</filename> in this case), and putting the result in
2940 the rule's target <Literal>$@</Literal> (<filename>Foo.o</filename> in this case).
2944 Every program is held in a <Command>make</Command> variable defined in
2945 <filename>mk/config.mk</filename>—look in <filename>mk/config.mk</filename> for the
2946 complete list. One important one is the Haskell compiler, which is
2947 called <constant>$(HC)</constant>.
2951 Every program's options are are held in a <Command>make</Command> variables called
2952 <constant><prog>_OPTS</constant>. the <constant><prog>_OPTS</constant> variables are defined in
2953 <filename>mk/opts.mk</filename>. Almost all of them are defined like this:
2959 CC_OPTS = $(SRC_CC_OPTS) $(WAY$(_way)_CC_OPTS) $($*_CC_OPTS) $(EXTRA_CC_OPTS)
2965 The four variables from which <constant>CC_OPTS</constant> is built have the following meaning:
2972 <term><constant>SRC_CC_OPTS</constant><indexterm><primary>SRC_CC_OPTS</primary></indexterm>:</term>
2975 options passed to all C
2978 </listitem></varlistentry>
2980 <term><constant>WAY_<way>_CC_OPTS</constant>:</term>
2984 compilations for way <Literal><way></Literal>. For example,
2985 <constant>WAY_mp_CC_OPTS</constant> gives options to pass to the C compiler when
2986 compiling way <Literal>mp</Literal>. The variable <constant>WAY_CC_OPTS</constant> holds
2987 options to pass to the C compiler when compiling the standard way.
2988 (<Xref LinkEnd="sec-ways"> dicusses multi-way
2991 </listitem></varlistentry>
2993 <term><constant><module>_CC_OPTS</constant>:</term>
2997 pass to the C compiler that are specific to module <Literal><module></Literal>. For example, <constant>SMap_CC_OPTS</constant> gives the specific options
2998 to pass to the C compiler when compiling <filename>SMap.c</filename>.
3000 </listitem></varlistentry>
3002 <term><constant>EXTRA_CC_OPTS</constant><indexterm><primary>EXTRA_CC_OPTS</primary></indexterm>:</term>
3005 extra options to pass to all
3006 C compilations. This is intended for command line use, thus:
3012 gmake libHS.a EXTRA_CC_OPTS="-v"
3016 </listitem></varlistentry>
3022 <Sect2 id="sec-targets">
3023 <Title>The main <filename>mk/target.mk</filename> file
3025 <indexterm><primary>target.mk</primary></indexterm></Title>
3028 <filename>target.mk</filename> contains canned rules for all the standard targets
3029 described in <Xref LinkEnd="sec-standard-targets">. It is complicated by the fact that you don't want all of
3030 these rules to be active in every <filename>Makefile</filename>. Rather than have a
3031 plethora of tiny files which you can include selectively, there is a
3032 single file, <filename>target.mk</filename>, which selectively includes rules based on
3033 whether you have defined certain variables in your <filename>Makefile</filename>. This
3034 section explains what rules you get, what variables control them, and
3035 what the rules do. Hopefully, you will also get enough of an idea of
3036 what is supposed to happen that you can read and understand any weird
3037 special cases yourself.
3044 <term><constant>HS_PROG</constant><indexterm><primary>HS_PROG</primary></indexterm>.</term>
3047 If <constant>HS_PROG</constant> is defined, you get
3048 rules with the following targets:
3052 <term><filename>HS_PROG</filename><indexterm><primary>HS_PROG</primary></indexterm></term>
3055 itself. This rule links <constant>$(OBJS)</constant>
3056 with the Haskell runtime system to get an executable called
3057 <constant>$(HS_PROG)</constant>.
3059 </listitem></varlistentry>
3061 <term><Literal>install</Literal><indexterm><primary>install</primary></indexterm></term>
3064 installs <constant>$(HS_PROG)</constant>
3065 in <constant>$(bindir)</constant>.
3067 </listitem></varlistentry>
3070 </listitem></varlistentry>
3072 <term><constant>C_PROG</constant><indexterm><primary>C_PROG</primary></indexterm></term>
3075 is similar to <constant>HS_PROG</constant>, except that
3076 the link step links <constant>$(C_OBJS)</constant> with the C runtime system.
3078 </listitem></varlistentry>
3080 <term><constant>LIBRARY</constant><indexterm><primary>LIBRARY</primary></indexterm></term>
3083 is similar to <constant>HS_PROG</constant>, except that
3084 it links <constant>$(LIB_OBJS)</constant> to make the library archive <constant>$(LIBRARY)</constant>, and
3085 <Literal>install</Literal> installs it in <constant>$(libdir)</constant>.
3087 </listitem></varlistentry>
3089 <term><constant>LIB_DATA</constant><indexterm><primary>LIB_DATA</primary></indexterm></term>
3094 </listitem></varlistentry>
3096 <term><constant>LIB_EXEC</constant><indexterm><primary>LIB_EXEC</primary></indexterm></term>
3101 </listitem></varlistentry>
3103 <term><constant>HS_SRCS</constant><indexterm><primary>HS_SRCS</primary></indexterm>, <constant>C_SRCS</constant><indexterm><primary>C_SRCS</primary></indexterm>.</term>
3106 If <constant>HS_SRCS</constant>
3107 is defined and non-empty, a rule for the target <Literal>depend</Literal> is included,
3108 which generates dependency information for Haskell programs.
3109 Similarly for <constant>C_SRCS</constant>.
3111 </listitem></varlistentry>
3116 All of these rules are ``double-colon'' rules, thus
3122 install :: $(HS_PROG)
3123 ...how to install it...
3129 GNU <Command>make</Command> treats double-colon rules as separate entities. If there
3130 are several double-colon rules for the same target it takes each in
3131 turn and fires it if its dependencies say to do so. This means that
3132 you can, for example, define both <constant>HS_PROG</constant> and <constant>LIBRARY</constant>, which will
3133 generate two rules for <Literal>install</Literal>. When you type <Command>gmake install</Command> both
3134 rules will be fired, and both the program and the library will be
3135 installed, just as you wanted.
3140 <Sect2 id="sec-subdirs">
3143 <indexterm><primary>recursion, in makefiles</primary></indexterm>
3144 <indexterm><primary>Makefile, recursing into subdirectories</primary></indexterm></Title>
3147 In leaf <filename>Makefile</filename>s the variable <constant>SUBDIRS</constant><indexterm><primary>SUBDIRS</primary></indexterm> is undefined.
3148 In non-leaf <filename>Makefile</filename>s, <constant>SUBDIRS</constant> is set to the list of
3149 sub-directories that contain subordinate <filename>Makefile</filename>s. <Emphasis>It is up to
3150 you to set <constant>SUBDIRS</constant> in the <filename>Makefile</filename>.</Emphasis> There is no automation here—<constant>SUBDIRS</constant> is too important to automate.
3154 When <constant>SUBDIRS</constant> is defined, <filename>target.mk</filename> includes a rather
3155 neat rule for the standard targets (<Xref LinkEnd="sec-standard-targets"> that simply invokes
3156 <Command>make</Command> recursively in each of the sub-directories.
3160 <Emphasis>These recursive invocations are guaranteed to occur in the order
3161 in which the list of directories is specified in <constant>SUBDIRS</constant>. </Emphasis>This
3162 guarantee can be important. For example, when you say <Command>gmake boot</Command> it
3163 can be important that the recursive invocation of <Command>make boot</Command> is done
3164 in one sub-directory (the include files, say) before another (the
3165 source files). Generally, put the most independent sub-directory
3166 first, and the most dependent last.
3171 <sect2 id="sec-ways">
3172 <title>Way management</title>
3173 <indexterm><primary>way management</primary></indexterm>
3175 <para>We sometimes want to build essentially the same system in
3176 several different ``ways''. For example, we want to build GHC's
3177 <literal>Prelude</literal> libraries with and without profiling,
3178 so that there is an appropriately-built library archive to link
3179 with when the user compiles his program. It would be possible
3180 to have a completely separate build tree for each such ``way'',
3181 but it would be horribly bureaucratic, especially since often
3182 only parts of the build tree need to be constructed in multiple
3186 <filename>target.mk</filename><indexterm><primary>target.mk</primary></indexterm>
3187 contains some clever magic to allow you to build several
3188 versions of a system; and to control locally how many versions
3189 are built and how they differ. This section explains the
3192 <para>The files for a particular way are distinguished by
3193 munging the suffix. The <quote>normal way</quote> is always
3194 built, and its files have the standard suffices
3195 <filename>.o</filename>, <filename>.hi</filename>, and so on.
3196 In addition, you can build one or more extra ways, each
3197 distinguished by a <emphasis>way tag</emphasis>. The object
3198 files and interface files for one of these extra ways are
3199 distinguished by their suffix. For example, way
3200 <literal>mp</literal> has files
3201 <filename>.mp_o</filename> and
3202 <filename>.mp_hi</filename>. Library archives have their
3203 way tag the other side of the dot, for boring reasons; thus,
3204 <filename>libHS_mp.a</filename>.</para>
3206 <para>A <Command>make</Command> variable called
3207 <constant>way</constant> holds the current way tag.
3208 <emphasis><constant>way</constant> is only ever set on the
3209 command line of <Command>gmake</Command></emphasis> (usually in
3210 a recursive invocation of <command>gmake</command> by the
3211 system). It is never set inside a
3212 <filename>Makefile</filename>. So it is a global constant for
3213 any one invocation of <Command>gmake</Command>. Two other
3214 <Command>make</Command> variables,
3215 <constant>way_</constant> and
3216 <constant>_way</constant> are immediately derived from
3217 <constant>$(way)</constant> and never altered. If
3218 <constant>way</constant> is not set, then neither are
3219 <constant>way_</constant> and
3220 <constant>_way</constant>, and the invocation of
3221 <Command>make</Command> will build the <quote>normal
3222 way</quote>. If <constant>way</constant> is set, then the other
3223 two variables are set in sympathy. For example, if
3224 <constant>$(way)</constant> is ``<Literal>mp</Literal>'',
3225 then <constant>way_</constant> is set to
3226 ``<Literal>mp_</Literal>'' and
3227 <constant>_way</constant> is set to
3228 ``<Literal>_mp</Literal>''. These three variables are
3229 then used when constructing file names.</para>
3231 <para>So how does <Command>make</Command> ever get recursively
3232 invoked with <constant>way</constant> set? There are two ways
3233 in which this happens:</para>
3237 <para>For some (but not all) of the standard targets, when
3238 in a leaf sub-directory, <Command>make</Command> is
3239 recursively invoked for each way tag in
3240 <constant>$(WAYS)</constant>. You set
3241 <constant>WAYS</constant> in the
3242 <filename>Makefile</filename> to the list of way tags you
3243 want these targets built for. The mechanism here is very
3244 much like the recursive invocation of
3245 <Command>make</Command> in sub-directories (<Xref
3246 LinkEnd="sec-subdirs">). It is up to you to set
3247 <constant>WAYS</constant> in your
3248 <filename>Makefile</filename>; this is how you control what
3249 ways will get built.</para>
3253 <para>For a useful collection of targets (such as
3254 <filename>libHS_mp.a</filename>,
3255 <filename>Foo.mp_o</filename>) there is a rule which
3256 recursively invokes <Command>make</Command> to make the
3257 specified target, setting the <constant>way</constant>
3258 variable. So if you say <Command>gmake
3259 Foo.mp_o</Command> you should see a recursive
3260 invocation <Command>gmake Foo.mp_o way=mp</Command>,
3261 and <Emphasis>in this recursive invocation the pattern rule
3262 for compiling a Haskell file into a <filename>.o</filename>
3263 file will match</Emphasis>. The key pattern rules (in
3264 <filename>suffix.mk</filename>) look like this:
3268 $(HC) $(HC_OPTS) $< -o $@
3275 <para>You can invoke <command>make</command> with a
3276 particular <literal>way</literal> setting yourself, in order
3277 to build files related to a particular
3278 <literal>way</literal> in the current directory. eg.
3284 will build files for the profiling way only in the current
3292 <Title>When the canned rule isn't right</Title>
3295 Sometimes the canned rule just doesn't do the right thing. For
3296 example, in the <Literal>nofib</Literal> suite we want the link step to print out
3297 timing information. The thing to do here is <Emphasis>not</Emphasis> to define
3298 <constant>HS_PROG</constant> or <constant>C_PROG</constant>, and instead define a special purpose rule in
3299 your own <filename>Makefile</filename>. By using different variable names you will avoid
3300 the canned rules being included, and conflicting with yours.
3307 <Sect1 id="sec-booting-from-C">
3308 <Title>Booting/porting from C (<filename>.hc</filename>) files
3310 <indexterm><primary>building GHC from .hc files</primary></indexterm>
3311 <indexterm><primary>booting GHC from .hc files</primary></indexterm>
3312 <indexterm><primary>porting GHC</primary></indexterm></Title>
3314 <para><emphasis>NOTE: GHC version 5.xx is significantly harder to
3315 bootstrap from C than previous versions. We recommend starting
3316 from version 4.08.2 if you need to bootstrap in this
3317 way.</emphasis></para>
3320 This section is for people trying to get GHC going by using the supplied
3321 intermediate C (<filename>.hc</filename>) files. This would probably be
3322 because no binaries have been provided, or because the machine is not ``fully
3327 The intermediate C files are normally made available together with a source
3328 release, please check the announce message for exact directions of where to
3329 find them. If we haven't made them available or you can't find them, please
3334 Assuming you've got them, unpack them on top of a fresh source tree. This
3335 will place matching <filename>.hc</filename> files next to the corresponding
3336 Haskell source in the compiler subdirectory <filename>ghc</filename> and in
3337 the language package of hslibs (i.e., in <filename>hslibs/lang</filename>).
3338 Then follow the `normal' instructions in <Xref
3339 LinkEnd="sec-building-from-source"> for setting up a build tree.
3343 The actual build process is fully automated by the
3344 <filename>hc-build</filename> script located in the
3345 <filename>distrib</filename> directory. If you eventually want to install GHC
3346 into the directory <filename>INSTALL_DIRECTORY</filename>, the following
3347 command will execute the whole build process (it won't install yet):
3350 foo% distrib/hc-build --prefix=INSTALL_DIRECTORY
3352 <indexterm><primary>--hc-build</primary></indexterm>
3354 By default, the installation directory is <filename>/usr/local</filename>. If
3355 that is what you want, you may omit the argument to
3356 <filename>hc-build</filename>. Generally, any option given to
3357 <filename>hc-build</filename> is passed through to the configuration script
3358 <filename>configure</filename>. If <filename>hc-build</filename>
3359 successfully completes the build process, you can install the resulting
3360 system, as normal, with
3367 That's the mechanics of the boot process, but, of course, if you're
3368 trying to boot on a platform that is not supported and significantly
3369 `different' from any of the supported ones, this is only the start of
3370 the adventure…(ToDo: porting tips—stuff to look out for, etc.)
3375 <Sect1 id="sec-build-pitfalls">
3376 <Title>Known pitfalls in building Glasgow Haskell
3378 <indexterm><primary>problems, building</primary></indexterm>
3379 <indexterm><primary>pitfalls, in building</primary></indexterm>
3380 <indexterm><primary>building pitfalls</primary></indexterm></Title>
3383 WARNINGS about pitfalls and known ``problems'':
3392 One difficulty that comes up from time to time is running out of space
3393 in <literal>TMPDIR</literal>. (It is impossible for the configuration stuff to
3394 compensate for the vagaries of different sysadmin approaches to temp
3396 <indexterm><primary>tmp, running out of space in</primary></indexterm>
3398 The quickest way around it is <Command>setenv TMPDIR /usr/tmp</Command><indexterm><primary>TMPDIR</primary></indexterm> or
3399 even <Command>setenv TMPDIR .</Command> (or the equivalent incantation with your shell
3402 The best way around it is to say
3405 export TMPDIR=<dir>
3408 in your <filename>build.mk</filename> file.
3409 Then GHC and the other <Literal>fptools</Literal> programs will use the appropriate directory
3418 In compiling some support-code bits, e.g., in <filename>ghc/rts/gmp</filename> and even
3419 in <filename>ghc/lib</filename>, you may get a few C-compiler warnings. We think these
3427 When compiling via C, you'll sometimes get ``warning: assignment from
3428 incompatible pointer type'' out of GCC. Harmless.
3435 Similarly, <Command>ar</Command>chiving warning messages like the following are not
3439 ar: filename GlaIOMonad__1_2s.o truncated to GlaIOMonad_
3440 ar: filename GlaIOMonad__2_2s.o truncated to GlaIOMonad_
3450 In compiling the compiler proper (in <filename>compiler/</filename>), you <Emphasis>may</Emphasis>
3451 get an ``Out of heap space'' error message. These can vary with the
3452 vagaries of different systems, it seems. The solution is simple:
3459 If you're compiling with GHC 4.00 or later, then the
3460 <Emphasis>maximum</Emphasis> heap size must have been reached. This
3461 is somewhat unlikely, since the maximum is set to 64M by default.
3462 Anyway, you can raise it with the
3463 <Option>-optCrts-M<size></Option> flag (add this flag to
3464 <constant><module>_HC_OPTS</constant>
3465 <Command>make</Command> variable in the appropriate
3466 <filename>Makefile</filename>).
3473 For GHC < 4.00, add a suitable <Option>-H</Option> flag to the <filename>Makefile</filename>, as
3482 and try again: <Command>gmake</Command>. (see <Xref LinkEnd="sec-suffix"> for information about
3483 <constant><module>_HC_OPTS</constant>.)
3485 Alternatively, just cut to the chase:
3489 % make EXTRA_HC_OPTS=-optCrts-M128M
3498 If you try to compile some Haskell, and you get errors from GCC about
3499 lots of things from <filename>/usr/include/math.h</filename>, then your GCC was
3500 mis-installed. <Command>fixincludes</Command> wasn't run when it should've been.
3502 As <Command>fixincludes</Command> is now automagically run as part of GCC installation,
3503 this bug also suggests that you have an old GCC.
3511 You <Emphasis>may</Emphasis> need to re-<Command>ranlib</Command><indexterm><primary>ranlib</primary></indexterm> your libraries (on Sun4s).
3515 % cd $(libdir)/ghc-x.xx/sparc-sun-sunos4
3516 % foreach i ( `find . -name '*.a' -print` ) # or other-shell equiv...
3518 ? # or, on some machines: ar s $i
3523 We'd be interested to know if this is still necessary.
3531 GHC's sources go through <Command>cpp</Command> before being compiled, and <Command>cpp</Command> varies
3532 a bit from one Unix to another. One particular gotcha is macro calls
3537 SLIT("Hello, world")
3541 Some <Command>cpp</Command>s treat the comma inside the string as separating two macro
3542 arguments, so you get
3546 :731: macro `SLIT' used with too many (2) args
3550 Alas, <Command>cpp</Command> doesn't tell you the offending file!
3552 Workaround: don't put weird things in string args to <Command>cpp</Command> macros.
3563 <Sect1 id="winbuild"><Title>Notes for building under Windows</Title>
3566 This section summarises how to get the utilities you need on your
3567 Win95/98/NT/2000 machine to use CVS and build GHC. Similar notes for
3568 installing and running GHC may be found in the user guide. In general,
3569 Win95/Win98 behave the same, and WinNT/Win2k behave the same.
3570 You should read the GHC installation guide sections on Windows (in the user
3571 guide) before continuing to read these notes.
3575 <Sect2><Title>Before you start</Title>
3580 Make sure that the user environment variable
3581 <constant>MAKE_MODE</constant> is set to <Literal>UNIX</Literal>. If you
3582 don't do this you get very weird messages when you type
3583 <Command>make</Command>, such as:
3585 /c: /c: No such file or directory
3591 <para>GHC uses the <emphasis>mingw</emphasis> C compiler to
3592 generate code, so you have to install that. Just pick up a mingw bundle at
3593 <ulink url="http://www.mingw.org/">http://www.mingw.org/</ulink>.
3594 We install it in <filename>c:/mingw</filename>.
3600 Install a version of GHC, and put it in your
3601 <constant>PATH</constant> (the installer tells you the path element
3602 you need to add upon completion.)
3609 Because of various hard-wired infelicities, you need to copy
3610 <Filename>bash.exe</Filename>, <Filename>perl.exe</Filename> and
3611 <Filename>cat.exe</Filename> (from Cygwin's <Filename>bin</Filename>
3612 directory), to <Filename>/bin</Filename> (discover where your Cygwin
3613 root directory is by typing <Command>mount</Command>). If
3614 <Command>/bin</Command> points to the Cygwin <Filename>bin</Filename>
3615 directory, there's no need to copy anything.
3621 By default, cygwin provides the command shell <filename>ash</filename>
3622 as <filename>sh.exe</filename>. It has a couple of 'issues', so
3623 in your <filename>/bin</filename> directory, make sure that <filename>
3624 bash.exe</filename> is also provided as <filename>sh.exe</filename>.
3630 <para> Both <command>cvs</command> and <command>ssh</command>
3631 come with Cygwin, but make sure you select them when running
3632 the Cygwin installer.
3636 <para> Check out a copy of GHC sources from
3637 the CVS repository, following the instructions above (<xref linkend="cvs-access">).
3643 <Sect2><Title>Building GHC</Title>
3649 Run <Command>autoconf</Command> both in <filename>fptools</filename>
3650 and in <filename>fptools/ghc</filename>. If you omit the latter step you'll
3651 get an error when you run <filename>./configure</filename>:
3654 creating mk/config.h
3655 mk/config.h is unchanged
3657 running /bin/sh ./configure --cache-file=.././config.cache --srcdir=.
3658 ./configure: ./configure: No such file or directory
3659 configure: error: ./configure failed for ghc
3666 You either need to add <filename>ghc</filename> to your
3667 <constant>PATH</constant> before you invoke
3668 <Command>configure</Command>, or use the <Command>configure</Command>
3669 option <option>--with-ghc=c:/ghc/ghc-some-version/bin/ghc</option>.
3673 The Windows installer for GHC tells you at the end what
3674 additions you need to make to your <constant>PATH</constant>.
3680 After <command>autoconf</command> run <command>./configure</command> in
3681 <filename>fptools/</filename> thus:
3684 ./configure --host=i386-unknown-mingw32 --with-gcc=/mingw/bin/gcc
3687 Both these options are important! It's possible to get into
3688 trouble using the wrong C compiler!
3698 <title>Building the Windows InstallShield® Installer</title>
3701 This section is intended for GHC developers only; no-one else
3702 should need to build an InstallShield.
3706 Having built a second-stage tree and done <command>make
3707 install</command> on it, open the InstallShield
3708 (<filename>.ism</filename>) file. Open the Project screen, and
3709 then the Project subfolder of the Path variables folder, and
3710 set <literal>SourceFiles</literal> to the top of your
3711 tree. You might also need to set <literal>GHCBITS</literal> to
3712 point to the tree of various external bits that are added into
3713 the IS mix. You should then be able to build an InstallShield.
3717 <title>Extra features of the InstallShield</title>
3720 The InstallShield has some IS-specific twiddles:
3725 Two registry entries are set under
3726 <literal>HKEY_LOCAL_MACHINE\SOFTWARE\GHC</literal>:
3727 <literal>Path</literal> and
3728 <literal>Version</literal>, which record respectively
3729 the directory in which GHC was installed, and the
3735 The InstallShield adds some entries to the Program
3736 menu, for GHCi and for the documentation. See under
3737 Setup Design and the individual components (each
3738 component can add entries to the menu).
3746 <title>External add-ins</title>
3749 The external add-ins consist of Mingwin gcc and Mingwin
3750 Perl. The layout of the add-ins tree is as follows:
3755 perl.exe (Mingwin perl)
3758 Mingwin gcc binaries, libraries and headers