lfs/chapter05/libstdc++.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../general.ent">
  %general-entities;
]>

<sect1 id="ch-tools-libstdcpp" role="wrap">
  <?dbhtml filename="gcc-libstdc++.html"?>

  <sect1info condition="script">
    <productname>gcc-libstdc++</productname>
    <productnumber>&gcc-version;</productnumber>
    <address>&gcc-url;</address>
  </sect1info>

  <title>Libstdc++ from GCC-&gcc-version;</title>

  <indexterm zone="ch-tools-libstdcpp">
    <primary sortas="a-GCC">GCC</primary>
    <secondary>tools, libstdc++ pass 1</secondary>
  </indexterm>

  <sect2 role="package">
    <title/>

    <para>Libstdc++ is the standard C++ library. It is needed
    to compile C++ code
    (part of GCC is written in C++), but we had to defer its installation
    when we built <xref linkend="ch-tools-gcc-pass1"/>
    because it depends on glibc, which was not yet available in the target
    directory.
    </para>

    <segmentedlist>
      <segtitle>&buildtime;</segtitle>
      <segtitle>&diskspace;</segtitle>

      <seglistitem>
        <seg>&libstdcpp-tmpp1-sbu;</seg>
        <seg>&libstdcpp-tmpp1-du;</seg>
      </seglistitem>
    </segmentedlist>

  </sect2>

  <sect2 role="installation">
    <title>Installation of Target Libstdc++</title>

    <note>
      <para><application>Libstdc++</application> is part of the GCC sources.
      You should first unpack the GCC tarball and change to the
      <filename>gcc-&gcc-version;</filename> directory.</para>
    </note>

    <para>Create a separate build directory for libstdc++ and enter it:</para>

<screen><userinput remap="pre">mkdir -v build
cd       build</userinput></screen>

    <para>Prepare libstdc++ for compilation:</para>

<screen><userinput remap="configure">../libstdc++-v3/configure           \
    --host=$LFS_TGT                 \
    --build=$(../config.guess)      \
    --prefix=/usr                   \
    --disable-multilib              \
    --disable-nls                   \
    --disable-libstdcxx-pch         \
    --with-gxx-include-dir=/tools/$LFS_TGT/include/c++/&gcc-version;</userinput></screen>

    <variablelist>
      <title>The meaning of the configure options:</title>

      <varlistentry>
        <term><parameter>--host=...</parameter></term>
        <listitem>
          <para>Specifies that the cross compiler we have just built
          should be used instead of the one in
          <filename>/usr/bin</filename>.</para>
        </listitem>
      </varlistentry>

      <varlistentry arch="ml_32,ml_x32,ml_all">
        <term><parameter>--disable-multilib</parameter></term>
        <listitem>
          <para>Even when building the multilib version, this switch is 
          given. This is because the additionally built libraries are
          not required in this stage and some disk space and compile
          time can be saved.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--disable-libstdcxx-pch</parameter></term>
        <listitem>
          <para>This switch prevents the installation of precompiled
          include files, which are not needed at this stage.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--with-gxx-include-dir=/tools/$LFS_TGT/include/c++/&gcc-version;</parameter></term>
        <listitem>
          <para>This specifies the installation directory for include files.
          Because libstdc++ is the standard C++ library for LFS, this
          directory should match the location where the C++ compiler
          (<command>$LFS_TGT-g++</command>) would search for the
          standard C++ include files. In a normal build, this information
          is automatically passed to the libstdc++ <command>configure</command>
          options from the top level directory. In our case, this information
          must be explicitly given.
          The C++ compiler will prepend the sysroot path
          <filename class="directory">$LFS</filename> (specified building
          GCC pass 1) to the include file search path, so it will actually
          search in
          <filename class="directory">$LFS/tools/$LFS_TGT/include/c++/&gcc-version;</filename>.
          The combination of the <parameter>DESTDIR</parameter>
          variable (in the <command>make install</command> command below)
          and this switch ensures to install the headers there.</para>
        </listitem>
      </varlistentry>

    </variablelist>

    <para>Compile libstdc++ by running:</para>

<screen><userinput remap="make">make</userinput></screen>

    <para>Install the library:</para>

<screen><userinput remap="install">make DESTDIR=$LFS install</userinput></screen>

  </sect2>

  <sect2 role="content">
    <title/>

    <para>Details on this package are located in
    <xref linkend="contents-gcc" role="."/></para>

  </sect2>

</sect1>