lfs-book/chapter05/gcc-pass1.xml

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<sect1 id="ch-tools-gcc-pass1" role="wrap">
  <?dbhtml filename="gcc-pass1.html"?>

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

  <title>GCC-&gcc-version; - Pass 1</title>

  <indexterm zone="ch-tools-gcc-pass1">
    <primary sortas="a-GCC">GCC</primary>
    <secondary>tools, pass 1</secondary>
  </indexterm>

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

    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
    href="../chapter06/gcc.xml"
    xpointer="xpointer(/sect1/sect2[1]/para[1])"/>

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

      <seglistitem>
        <seg>&gcc-ch5p1-sbu;</seg>
        <seg>&gcc-ch5p1-du;</seg>
      </seglistitem>
    </segmentedlist>

  </sect2>

  <sect2 role="installation">
    <title>Installation of Cross GCC</title>

    <para>GCC now requires the GMP, MPFR and MPC packages. As these packages may
    not be included in your host distribution, they will be built with
    GCC:</para>

<screen><userinput remap="pre">tar -jxf ../mpfr-&mpfr-version;.tar.bz2
mv -v mpfr-&mpfr-version; mpfr
tar -jxf ../gmp-&gmp-version;.tar.bz2
mv -v gmp-&gmp-version; gmp
tar -zxf ../mpc-&mpc-version;.tar.gz
mv -v mpc-&mpc-version; mpc</userinput></screen>

    <para>The GCC documentation recommends building GCC outside of the
    source directory in a dedicated build directory:</para>

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

    <para>Prepare GCC for compilation:</para>

<screen><userinput remap="configure">../gcc-&gcc-version;/configure \
    --target=$LFS_TGT --prefix=/tools \
    --disable-nls --disable-shared --disable-multilib \
    --disable-decimal-float --disable-threads \
    --disable-libmudflap --disable-libssp \
    --disable-libgomp --enable-languages=c \
    --with-gmp-include=$(pwd)/gmp --with-gmp-lib=$(pwd)/gmp/.libs</userinput></screen>

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

      <varlistentry>
        <term><parameter>--disable-shared</parameter></term>
        <listitem>
          <para>This switch forces GCC to link its internal libraries
          statically. We do this to avoid possible issues with the host
          system.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--disable-decimal-float, --disable-threads, --disable-libmudflap, --disable-libssp, --disable-libgomp</parameter></term>
        <listitem>
          <para>These switches disable support for the decimal floating point extension,
          threading, libmudflap, libssp and libgomp respectively. These features will fail
          to compile when building a cross-compiler and are not necessary for the task of
          cross-compiling the temporary libc.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--disable-multilib</parameter></term>
        <listitem>
          <para>On x86_64, LFS does not yet support a multilib configuration.
          This switch is harmless for x86.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--enable-languages=c</parameter></term>
        <listitem>
          <para>This option ensures that only the C compiler is built.
          This is the only language needed now.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--with-gmp-include=...</parameter></term>
        <listitem>
          <para>This option tells GCC where the GMP headers are located.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--with-gmp-lib=...</parameter></term>
        <listitem>
          <para>This option tells GCC where the GMP library is located.</para>
        </listitem>
      </varlistentry>

    </variablelist>

    <para>Compile GCC by running:</para>

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

    <para>Compilation is now complete. At this point, the test suite would
    normally be run, but, as mentioned before, the test suite framework is
    not in place yet. The benefits of running the tests at this point
    are minimal since the programs from this first pass will soon be
    replaced.</para>

    <para>Install the package:</para>

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

    <para>Using <parameter>--disable-shared</parameter> means that the
    <filename>libgcc_eh.a</filename> file isn't created and installed. The
    Glibc package depends on this library as it uses
    <parameter>-lgcc_eh</parameter> within its build system. This dependency
    can be satisfied by creating a symlink to <filename>libgcc.a</filename>,
    since that file will end up containing the objects normally contained in
    <filename>libgcc_eh.a</filename>:</para>

<screen><userinput remap="install">ln -vs libgcc.a `$LFS_TGT-gcc -print-libgcc-file-name | \
    sed 's/libgcc/&amp;_eh/'`</userinput></screen>

  </sect2>

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

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

  </sect2>

</sect1>