[project @ 2002-06-15 20:23:12 by wolfgang]
[ghc-hetmet.git] / ghc / docs / users_guide / packages.sgml
index 5e2ce43..b778a50 100644 (file)
@@ -14,8 +14,8 @@
     layer over a C library.</para>
 
     <para>GHC comes with several packages (see <xref
-    linkend="book-hslibs">), and packages can be added/removed from an
-    existing GHC installation, using the supplied
+    linkend="book-hslibs">), and packages can be added to or removed
+    from an existing GHC installation, using the supplied
     <literal>ghc-pkg</literal><indexterm><primary><literal>ghc-pkg</literal></primary>
     </indexterm> tool, described in <xref
     linkend="package-management">.</para>
       automatically get <literal>-package lang</literal> too.</para>
     </sect2>
 
+    <sect2 id="using-local-packages">
+      <title>Maintaining a local set of packages</title>
+      
+      <para>When GHC starts up, it automatically reads the default set
+      of packages from a configuration file, normally named
+      <filename>package.conf</filename> in your GHC installation
+      directory.</para>
+
+      <para>You can load in additional package configuration files
+      using the <option>-package-conf</option> option:</para>
+
+      <variablelist>
+       <varlistentry>
+         <term><option>-package-conf <replaceable>file</replaceable></option></term>
+         <indexterm><primary><option>-package-conf <replaceable>file</replaceable></option></primary>
+         </indexterm>
+         <listitem>
+           <para>Read in the package configuration file
+           <replaceable>file</replaceable> in addition to the system
+           default file.  This allows the user to have a local set of
+           packages in addition to the system-wide ones.</para>
+         </listitem>
+       </varlistentry>
+      </variablelist>
+
+      <para>To create your own package configuration file, just create
+      a new file and put the string
+      <quote><literal>[]</literal></quote> in it.  Packages can be
+      added to the new configuration file using the
+      <literal>ghc-pkg</literal> tool, described in <xref
+      linkend="package-management">.</para>
+    </sect2>
+
     <sect2 id="building-packages">
       <title>Building a package from Haskell source</title>
       <indexterm><primary>packages</primary>
 
        <listitem>
          <para>The Haskell code in a package may be built into one or
-         more Unix libraries (e.g. <filename>libHSfoo.a</filename>),
+         more archive libraries (e.g. <filename>libHSfoo.a</filename>),
          or a single DLL on Windows
          (e.g. <filename>HSfoo.dll</filename>).  The restriction to a
          single DLL on Windows is that the package system is used to
          tell the compiler when it should make an inter-DLL call
          rather than an intra-DLL call (inter-DLL calls require an
-         extra indirection). <Strong>Building packages as DLLs
+         extra indirection). <emphasis>Building packages as DLLs
          doesn't work at the moment; see <XRef
-         LinkEnd="win32-dlls-create"> for the gory details.</Strong>
+         LinkEnd="win32-dlls-create"> for the gory details.</emphasis>
          </para>
 
          <para>Versions of the Haskell libraries for use with GHCi
          may also be included: GHCi cannot load <literal>.a</literal>
          files directly, instead it will look for an object file
-         called <filename>HSfoo.o</filename> (the object suffix
-         varies between platforms, as usual) and load that.  An
-         object file can be built from a <literal>.a</literal>
-         archive as follows (using GNU <command>ld</command> on
-         Unix):</para>
-
-<screen>
-ld -r --whole-archive -o HSfoo.o libHSfoo.a
-</screen>
+         called <filename>HSfoo.o</filename> and load that.  The
+         <literal>ghc-pkg</literal> tool can automatically build the
+         GHCi version of each library, see <xref
+         linkend="package-management">.  To build these libraries by
+         hand from the <literal>.a</literal> archive, it is possible
+         to use GNU <command>ld</command> as follows:</para>
+
+<screen>ld -r &ndash;&ndash;whole-archive -o HSfoo.o libHSfoo.a</screen>
        </listitem>
 
        <listitem>
@@ -142,23 +174,90 @@ ld -r --whole-archive -o HSfoo.o libHSfoo.a
       <indexterm><primary>packages</primary>
        <secondary>management</secondary></indexterm>
       
-      <para>GHC uses a package configuration file, called
-      <literal>packages.conf</literal>, which can be found in your GHC
-      install directory.  This file isn't intended to be edited
-      directly, instead packages can be added or removed using GHC's
-      package management tool, <literal>ghc-pkg</literal>.</para>
+      <para>The <literal>ghc-pkg</literal> tool allows packages to be
+      added or removed from a package configuration file.  By default,
+      the system-wide configuration file is used, but alternatively
+      packages can be added, updated or removed from a user-specified
+      configuration file using the <option>&ndash;&ndash;config-file</option>
+      option.  An empty package configuration file consists of the
+      string <quote><literal>[]</literal></quote>.</para>
+
+      <para>The <literal>ghc-pkg</literal> program accepts the
+      following options:</para>
 
       <variablelist>
        <varlistentry>
-         <term><option>--list-packages</option></term>
+         <term><option>&ndash;&ndash;add-package</option></term>
+         <term><option>-a</option></term>
+         <indexterm><primary><option>&ndash;&ndash;add-package</option></primary></indexterm>
+         <listitem>
+           <para>Reads package specification from the input (see below),
+           and adds it to the database of installed packages.  The
+           package specification must be a package that isn't already
+           installed.</para>
+         </listitem>
+       </varlistentry>
+
+       <varlistentry>
+         <term><option>&ndash;&ndash;input-file=<replaceable>file</replaceable></option></term>
+         <term><option>-i <replaceable>file</replaceable></option></term>
+         <indexterm><primary><option>&ndash;&ndash;input-file</option></primary></indexterm>
+         <listitem>
+           <para>Read new package specifications from file
+           <replaceable>file</replaceable>. If a value of
+           <filename>"-"</filename> is given, standard input is used.
+           If no <option>-i</option> is present on the command-line,
+           an input file of <filename>"-"</filename> is assumed.
+           </para>
+         </listitem>
+       </varlistentry>
+
+       <varlistentry>
+         <term><option>&ndash;&ndash;auto-ghci-libs</option></term>
+         <term><option>-g</option></term>
+         <indexterm><primary><option>&ndash;&ndash;auto-ghci-libs</option></primary>
+             </indexterm>
+         <listitem>
+           <para>Automatically generate the GHCi
+           <filename>.o</filename> version of each
+           <filename>.a</filename> Haskell library, using GNU ld (if
+           that is available).  Without this option,
+           <literal>ghc-pkg</literal> will warn if GHCi versions of
+           any Haskell libraries in the package don't exist.</para>
+           
+           <para>GHCi <literal>.o</literal> libraries don't
+           necessarily have to live in the same directory as the
+           corresponding <literal>.a</literal> library.  However,
+           this option will cause the GHCi library to be created in
+           the same directory as the <literal>.a</literal>
+           library.</para>
+         </listitem>
+       </varlistentry>
+
+       <varlistentry>
+         <term><option>&ndash;&ndash;config-file <replaceable>file</replaceable></option></term>
+         <term><option>-f <replaceable>file</replaceable></option></term>
+         <indexterm><primary><option>&ndash;&ndash;config-file</option></primary>
+             </indexterm>
+         <listitem>
+           <para>Use <replaceable>file</replaceable> instead of the
+           default package configuration file.  This, in conjunction
+           with GHC's <option>-package-conf</option> option, allows
+           a user to have a local set of packages in addition to the
+           system-wide installed set.</para>
+         </listitem>
+       </varlistentry>
+
+       <varlistentry>
+         <term><option>&ndash;&ndash;list-packages</option></term>
          <term><option>-l</option></term>
-         <indexterm><primary><option>--list-packages</option></primary></indexterm>
+         <indexterm><primary><option>&ndash;&ndash;list-packages</option></primary></indexterm>
          <listitem>
            <para>This option displays the list of currently installed
            packages.</para>
 
 <screen>
-  $ ghc-pkg --list-packages
+  $ ghc-pkg &ndash;&ndash;list-packages
   gmp, rts, std, lang, concurrent, data, net, posix, text, util
 </screen>
 
@@ -176,44 +275,55 @@ ld -r --whole-archive -o HSfoo.o libHSfoo.a
        </varlistentry>
 
        <varlistentry>
-         <term><option>--add-package</option></term>
-         <term><option>-a</option></term>
-         <indexterm><primary><option>--add-package</option></primary>
+         <term><option>&ndash;&ndash;remove-package <replaceable>foo</replaceable></option></term>
+         <term><option>-r <replaceable>foo</replaceable></option></term>
+         <indexterm><primary><option>&ndash;&ndash;delete-package</option></primary>
              </indexterm>
          <listitem>
-           <para>Reads a package specification (see below) on stdin,
-           and adds it to the database of installed packages.  The
-           package specification must be a package that isn't already
-           installed.</para>
+           <para>Removes the specified package from the installed
+           configuration.</para>
          </listitem>
        </varlistentry>
-
        <varlistentry>
-         <term><option>--remove-package <replaceable>foo</replaceable></option></term>
-         <term><option>-r <replaceable>foo</replaceable></option></term>
-         <indexterm><primary><option>--delete-package</option></primary>
-             </indexterm>
+         <term><option>&ndash;&ndash;update-package</option></term>
+         <term><option>-u</option></term>
+         <indexterm><primary><option>&ndash;&ndash;update-package</option></primary></indexterm>
          <listitem>
-           <para>Removes the specified package from the installed
-           configuration.</para>
+           <para>Reads package specification from the input, and
+           adds it to the database of installed packages. If a package
+           with the same name is already installed, its configuration
+           data is replaced with the new information. If the package
+           doesn't already exist, it's added.
+           </para>
+         </listitem>
+       </varlistentry>
+       <varlistentry>
+         <term><option>&ndash;&ndash;force</option></term>
+         <indexterm><primary><option>&ndash;&ndash;force</option></primary></indexterm>
+         <listitem>
+           <para>Causes <literal>ghc-pkg</literal> to ignore missing
+           directories and libraries when adding a package, and just
+           go ahead and add it anyway.  This might be useful if your
+           package installation system needs to add the package to
+           GHC before building and installing the files.</para>
          </listitem>
        </varlistentry>
       </variablelist>
 
-      <para>In both cases, the old package configuration file is saved
-      in <literal>packages.conf.old</literal> in your GHC install
-      directory, so in an emergency you can always copy this file into
-      <literal>package.conf</literal> to restore the old
-      settings.</para>
+      <para>When modifying the configuration file
+      <replaceable>file</replaceable>, a copy of the original file is
+      saved in <replaceable>file</replaceable><literal>.old</literal>,
+      so in an emergency you can always restore the old settings by
+      copying the old file back again.</para>
 
       <para>A package specification looks like this:</para>
 
 <screen>
   Package {
      name            = "mypkg",
-     import_dirs     = ["/usr/local/lib/imports/mypkg"],
+     import_dirs     = ["${installdir}/imports/mypkg"],
      source_dirs     = [],
-     library_dirs    = ["/usr/local/lib"],
+     library_dirs    = ["${installdir}"],
      hs_libraries    = ["HSmypkg" ],
      extra_libraries = ["HSmypkg_cbits"],
      include_dirs    = [],
@@ -236,7 +346,7 @@ ld -r --whole-archive -o HSfoo.o libHSfoo.a
          <listitem>
             <para>The package's name, for use with
             the <literal>-package</literal> flag and as listed in the
-            <literal>--list-packages</literal> list. 
+            <literal>&ndash;&ndash;list-packages</literal> list. 
             </para>
          </listitem>
        </varlistentry>
@@ -417,7 +527,50 @@ ld -r --whole-archive -o HSfoo.o libHSfoo.a
            (for linking) when this package is being used.</para>
          </listitem>
        </varlistentry>
+       
+       <varlistentry>
+         <term><literal>framework_dirs</literal></term>
+         <indexterm><primary><literal>framework_dirs</literal></primary>
+           <secondary>package specification</secondary></indexterm>
+         <listitem>
+           <para>On Darwin/MacOS X, a list of directories containing frameworks for this
+           package. This corresponds to the <option>-framework-path</options> option.
+           It is ignored on all other platforms.</para>
+         </listitem>
+       </varlistentry>
+
+       <varlistentry>
+         <term><literal>extra_frameworks</literal></term>
+         <indexterm><primary><literal>extra_frameworks</literal></primary>
+           <secondary>package specification</secondary></indexterm>
+         <listitem>
+           <para>On Darwin/MacOS X, a list of frameworks to link to. This corresponds to the
+           <option>-framework</option> option. Take a look at Apple's developer documentation
+           to find out what frameworks actually are. This entry is ignored on all other platforms.</para>
+         </listitem>
+       </varlistentry>
       </variablelist>
+      
+      <para>
+      The <literal>ghc-pkg</literal> tool performs expansion of
+      environment variables occurring in input package specifications.
+      So, if the <literal>mypkg</literal> was added to the package
+      database as follows:
+      </para>
+<screen>
+  $ installdir=/usr/local/lib ghc-pkg -a < mypkg.pkg
+</screen>
+      
+      <para>
+      The occurrence of <literal>${installdir}</literal> is replaced
+      with <literal>/usr/local/lib</literal> in the package data that
+      is added for <literal>mypkg</literal>.
+      </para>
+      
+      <para>
+      This feature enables the distribution of package specification
+      files that can be easily configured when installing.
+      </para>
 
       <para>For examples of more package specifications, take a look
       at the <literal>package.conf</literal> in your GHC