source: BOOK/final-system/common/gcc.xml@ 917be50

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

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

  <indexterm zone="ch-system-gcc">
    <primary sortas="a-GCC">GCC</primary>
  </indexterm>

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

    <para>The GCC package contains the GNU compiler collection, which includes
    the C and C++ compilers.</para>

  </sect2>

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

    <para os="p1">The following patch fixes the searching of multilib dirs for
    specs file. The patch standardizes the gcc drivers path iteration functions,
    ensuring multilib directories are searched in the correct order. This fixes
    various issues, most noticably with libtool on multilib systems:</para>

<screen os="p2"><userinput>patch -Np1 -i ../&gcc-PR20425-patch;</userinput></screen>

    <para os="d">Apply a <command>sed</command> substitution that will suppress the
    installation of <filename class="libraryfile">libiberty.a</filename>. The
    version of <filename class="libraryfile">libiberty.a</filename> provided by
    Binutils will be used instead:</para>

<screen os="e"><userinput>sed -i 's/install_to_$(INSTALL_DEST) //' libiberty/Makefile.in</userinput></screen>

    <para os="e1">GCC provides a <command>gccbug</command> script which detects at
    compile time whether mktemp is present, and hardcodes the result in a test.
    If mktemp is not found, the script will fall back to using less
    random names for temporary files.  We will be installing mktemp
    later, so the following sed will simulate its presence:</para>

<screen os="e2"><userinput>sed -i 's/@have_mktemp_command@/yes/' gcc/gccbug.in</userinput></screen>

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

<screen os="g"><userinput>mkdir -v ../gcc-build
cd ../gcc-build</userinput></screen>

    <para os="h">Prepare GCC for compilation:</para>

<screen os="i"><userinput>../gcc-&gcc-version;/configure --prefix=/usr \
    --libexecdir=/usr/lib --enable-shared --enable-threads=posix \
    --enable-__cxa_atexit --enable-c99 --enable-long-long \
    --enable-clocale=gnu --enable-languages=c,c++ \
    --disable-multilib --disable-libstdcxx-pch</userinput></screen>

    <para os="j">Compile the package:</para>

<screen os="k"><userinput>make bootstrap</userinput></screen>

    <important os="l">
      <para>The test suite for GCC is considered
      critical. Do not skip it under any circumstance.</para>
    </important>

    <para os="m">Test the results, but do not stop at errors:</para>

<screen os="n"><userinput>make -k check</userinput></screen>

    <para os="o">The <parameter>-k</parameter> flag is used to make the test suite
    run through to completion and not stop at the first failure. The GCC test
    suite is very comprehensive and is almost guaranteed to generate a few
    failures. To receive a summary of the test suite results, run:</para>

<screen os="p"><userinput>../gcc-&gcc-version;/contrib/test_summary</userinput></screen>

    <para os="q">For only the summaries, pipe the output through
    <userinput>grep -A7 Summ</userinput>.</para>

    <para os="r">A few unexpected failures cannot always be avoided. The
    GCC developers are usually aware of these issues, but have not
    resolved them yet.</para>

    <para os="s">Install the package:</para>

<screen os="t"><userinput>make install</userinput></screen>

    <para os="u">Some packages expect the C preprocessor to be installed in the
    <filename class="directory">/lib</filename> directory.
    To support those packages, create this symlink:</para>

<screen os="v"><userinput>ln -sv ../usr/bin/cpp /lib</userinput></screen>

    <para os="w">Many packages use the name <command>cc</command> to call the C
    compiler. To satisfy those packages, create a symlink:</para>

<screen os="x"><userinput>ln -sv gcc /usr/bin/cc</userinput></screen>

  </sect2>

  <sect2 id="contents-gcc" role="content">
    <title>Contents of GCC</title>

    <segmentedlist>
      <segtitle>Installed programs</segtitle>
      <segtitle>Installed libraries</segtitle>

      <seglistitem>
        <seg>c++, cc (link to gcc), cpp, g++, gcc, gccbug, and gcov</seg>
        <seg>libgcc.a, libgcc_eh.a, libgcc_s.so, libmudflap.[a,so], 
        libmudflapth.[a,so], libstdc++.[a,so], and
        libsupc++.a</seg>
      </seglistitem>
    </segmentedlist>

    <variablelist>
      <bridgehead renderas="sect3">Short Descriptions</bridgehead>
      <?dbfo list-presentation="list"?>
      <?dbhtml list-presentation="table"?>

      <varlistentry id="cc">
        <term><command>cc</command></term>
        <listitem>
          <para>The C compiler</para>
          <indexterm zone="ch-system-gcc cc">
            <primary sortas="b-cc">cc</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="cpp">
        <term><command>cpp</command></term>
        <listitem>
          <para>The C preprocessor; it is used by the compiler to expand the
          #include, #define, and similar statements in the source files</para>
          <indexterm zone="ch-system-gcc cpp">
            <primary sortas="b-cpp">cpp</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="c">
        <term><command>c++</command></term>
        <listitem>
          <para>The C++ compiler</para>
          <indexterm zone="ch-system-gcc c">
            <primary sortas="b-c++">c++</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="g">
        <term><command>g++</command></term>
        <listitem>
          <para>The C++ compiler</para>
          <indexterm zone="ch-system-gcc g">
            <primary sortas="b-g++">g++</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="gcc">
        <term><command>gcc</command></term>
        <listitem>
          <para>The C compiler</para>
          <indexterm zone="ch-system-gcc gcc">
            <primary sortas="b-gcc">gcc</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="gccbug">
        <term><command>gccbug</command></term>
        <listitem>
          <para>A shell script used to help create useful bug reports</para>
          <indexterm zone="ch-system-gcc gccbug">
            <primary sortas="b-gccbug">gccbug</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="gcov">
        <term><command>gcov</command></term>
        <listitem>
          <para>A coverage testing tool; it is used to analyze programs to
          determine where optimizations will have the most effect</para>
          <indexterm zone="ch-system-gcc gcov">
            <primary sortas="b-gcov">gcov</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libgcc">
        <term><filename class="libraryfile">libgcc</filename></term>
        <listitem>
          <para>Contains run-time support for <command>gcc</command></para>
          <indexterm zone="ch-system-gcc libgcc">
            <primary sortas="c-libgcc*">libgcc*</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libmudflap">
        <term><filename class="libraryfile">libmudflap</filename></term>
        <listitem>
          <para>The libmudflap libraries are used by GCC for instrumenting
          pointer and array dereferencing operations.</para>
          <indexterm zone="ch-system-gcc libmudflap">
            <primary sortas="c-libmudflap*">libmudflap*</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libstdc">
        <term><filename class="libraryfile">libstdc++</filename></term>
        <listitem>
          <para>The standard C++ library</para>
          <indexterm zone="ch-system-gcc libstdc">
            <primary sortas="c-libstdc++">libstdc++</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libsupc">
        <term><filename class="libraryfile">libsupc++</filename></term>
        <listitem>
          <para>Provides supporting routines for the C++ programming
          language</para>
          <indexterm zone="ch-system-gcc libsupc">
            <primary sortas="c-libsupc++">libsupc++</primary>
          </indexterm>
        </listitem>
      </varlistentry>

    </variablelist>

  </sect2>

</sect1>