mirror of
https://git.linuxfromscratch.org/lfs.git
synced 2025-01-19 13:37:39 +00:00
d0dfce439e
git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@3106 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689
102 lines
4.2 KiB
XML
102 lines
4.2 KiB
XML
<sect1 id="ch05-gcc-pass1">
|
|
<title>Installing GCC-&gcc-version; - Pass 1</title>
|
|
<?dbhtml filename="gcc-pass1.html" dir="chapter05"?>
|
|
|
|
<screen>Estimated build time: &gcc-time-tools-pass1;
|
|
Estimated required disk space: &gcc-compsize-tools-pass1;</screen>
|
|
|
|
&aa-gcc-shortdesc;
|
|
&aa-gcc-dep;
|
|
|
|
<sect2><title> </title><para> </para></sect2>
|
|
|
|
<sect2>
|
|
<title>Installation of GCC</title>
|
|
|
|
<para>Unpack only the GCC-core tarball, as we won't be needing a C++ compiler
|
|
for the moment.</para>
|
|
|
|
<note><para>Even though GCC is an important toolchain package, we are not
|
|
going to run the test suite at this early stage. First, the test suite framework
|
|
is not yet in place and second, the programs from this first pass will soon be
|
|
overwritten by those installed in the second pass.</para></note>
|
|
|
|
<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>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>Prepare GCC for compilation:</para>
|
|
|
|
<screen><userinput>../gcc-&gcc-version;/configure --prefix=/tools \
|
|
--with-local-prefix=/tools \
|
|
--disable-nls --enable-shared \
|
|
--enable-languages=c</userinput></screen>
|
|
|
|
<para>The meaning of the configure options:</para>
|
|
|
|
<itemizedlist>
|
|
<listitem><para><userinput>--with-local-prefix=/tools</userinput>: The
|
|
purpose of this switch is to remove <filename>/usr/local/include</filename>
|
|
from <userinput>gcc</userinput>'s include search path. This is not absolutely
|
|
essential; however, we want to try to minimize the influence of the host
|
|
system, thus making this a sensible thing to do.</para></listitem>
|
|
|
|
<listitem><para><userinput>--enable-shared</userinput>: This switch may
|
|
seem counter-intuitive at first. But using it allows the building of
|
|
<filename>libgcc_s.so.1</filename> and <filename>libgcc_eh.a</filename>, and
|
|
having <filename>libgcc_eh.a</filename> available ensures that the configure
|
|
script for Glibc (the next package we compile) produces the proper results.
|
|
Note that the <userinput>gcc</userinput> binaries will still be linked
|
|
statically, as this is controlled by the <userinput>-static</userinput>
|
|
value of BOOT_LDFLAGS further on.</para></listitem>
|
|
|
|
<listitem><para><userinput>--enable-languages=c</userinput>: This option
|
|
ensures that only the C compiler is built. The option is only needed when you
|
|
have downloaded and unpacked the full GCC tarball.</para></listitem>
|
|
</itemizedlist>
|
|
|
|
<para>Continue with compiling the package:</para>
|
|
|
|
<screen><userinput>make BOOT_LDFLAGS="-static" bootstrap</userinput></screen>
|
|
|
|
<para>The meaning of the make parameters:</para>
|
|
|
|
<itemizedlist>
|
|
<listitem><para><userinput>BOOT_LDFLAGS="-static"</userinput>: This tells
|
|
GCC to link its programs statically.</para></listitem>
|
|
|
|
<listitem><para><userinput>bootstrap</userinput>: This target doesn't just
|
|
compile GCC, but compiles it several times. It uses the programs compiled in
|
|
a first round to compile itself a second time, and then again a third time.
|
|
It then compares these second and third compiles to make sure it can
|
|
reproduce itself flawlessly, which most probably means that it was
|
|
compiled correctly.</para></listitem>
|
|
</itemizedlist>
|
|
|
|
<para>And install the package:</para>
|
|
|
|
<screen><userinput>make install</userinput></screen>
|
|
|
|
<para>As a finishing touch we'll create the <filename
|
|
class="symlink">/tools/bin/cc</filename> symlink. Many programs and
|
|
scripts run <userinput>cc</userinput> instead of <userinput>gcc</userinput>,
|
|
a thing meant to keep programs generic and therefore usable on all kinds of
|
|
Unix systems. Not everybody has the GNU C compiler installed. Simply running
|
|
<userinput>cc</userinput> leaves the system administrator free to decide what
|
|
C compiler to install, as long as there's a symlink pointing to it:</para>
|
|
|
|
<screen><userinput>ln -sf gcc /tools/bin/cc</userinput></screen>
|
|
|
|
</sect2>
|
|
|
|
</sect1>
|
|
|