lfs-book-zh_CN/chapter06/gcc.xml

<sect1 id="ch-system-gcc" xreflabel="GCC">
<title>Installing GCC-&gcc-version;</title>
<?dbhtml filename="gcc.html" dir="chapter06"?>

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

<screen>&buildtime; &gcc-time;
&diskspace; &gcc-compsize;</screen>

<literallayout>Official download location for GCC (&gcc-version;): 
<ulink url="ftp://ftp.gnu.org/pub/gnu/gcc/"/>
And for the GCC No-Fixincludes Patch:
<ulink url="&patches-root;&gcc-nofixincludes-patch;"/></literallayout>

&aa-gcc-dep;

<sect2><title>&nbsp;</title><para>&nbsp;</para></sect2>

<sect2>
<title>Installation of GCC</title>

<para>This package is known to behave badly when you have changed its
default optimization flags (including the -march and -mcpu options).
Therefore, if you have defined any environment variables that override
default optimizations, such as CFLAGS and CXXFLAGS, we recommend unsetting
or modifying them when building GCC.</para>

<para>Unpack the GCC-core <emphasis>and</emphasis> the GCC-g++ tarball -- they
will unfold into the same directory. You should likewise extract the
GCC-testsuite package. The full GCC package contains even more
compilers. Instructions for building these can be found at
<ulink url="&blfs-root;view/stable/general/gcc.html"/>.</para>

<note><para>Be careful <emphasis role="strong">not</emphasis> to apply the GCC
Specs patch from <xref linkend="chapter05"/> here.</para></note>

<para>First apply the No-Fixincludes patch that we also used in the previous
chapter:</para>

<screen><userinput>patch -Np1 -i ../&gcc-nofixincludes-patch;</userinput></screen>

<para>Now apply a sed substitution that will suppress the installation of
<filename>libiberty.a</filename>. We want to use the version of
<filename>libiberty.a</filename> provided by Binutils:</para>

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

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

<screen><userinput>mkdir ../gcc-build
cd ../gcc-build</userinput></screen>

<para>Now prepare GCC for compilation:</para>

<screen><userinput>../&gcc-dir;/configure --prefix=/usr \
&nbsp;&nbsp;&nbsp;&nbsp;--enable-shared --enable-threads=posix \
&nbsp;&nbsp;&nbsp;&nbsp;--enable-__cxa_atexit --enable-clocale=gnu \
&nbsp;&nbsp;&nbsp;&nbsp;--enable-languages=c,c++</userinput></screen>

<para>Compile the package:</para>

<screen><userinput>make</userinput></screen>

<important><para>The test suite for GCC in this section is considered
<emphasis>critical</emphasis>. Our advice is to not skip it under any
circumstance.</para></important>

<para>Test the results, but don't stop at errors (you'll remember the few
known ones):</para>

<screen><userinput>make -k check</userinput></screen>

<para>The test suite notes from <xref linkend="ch-tools-gcc-pass2"/> are still very
much appropriate here. Be sure to refer back there should you have any
doubts.</para>

<para>And install the package:</para>

<screen><userinput>make install</userinput></screen>

<para>Some packages expect the C PreProcessor to be installed in the
<filename>/lib</filename> directory.
To honor those packages, create this symlink:</para>

<screen><userinput>ln -s ../usr/bin/cpp /lib</userinput></screen>

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

<screen><userinput>ln -s gcc /usr/bin/cc</userinput></screen>

<note><para>At this point it is strongly recommended to repeat the sanity check
we performed earlier in this chapter. Refer back to
<xref linkend="ch-system-adjustingtoolchain"/> and repeat the check. If the results
are wrong, then most likely you erroneously applied the GCC Specs patch from
<xref linkend="chapter05"/>.</para></note>

</sect2>

&aa-gcc-shortdesc;
&aa-gcc-desc;

</sect1>