lfs-book/chapter05/gcc-exp.xml

<sect2>
<title>Command explanations</title>

<para><userinput>patch -Np1 -i ../gcc-&gcc-patch-version;.patch:</userinput>
This patch fixes a few bugs. In particular it contains the "copy fix" and
"var fix" documented at 
<ulink url="http://www.zipworld.com.au/~gschafer/lfs-tweaks.html"/>.</para>

<para><userinput>patch -Np1 -i ../gcc-3.2-nofixincludes-2.patch:</userinput>
This prevents the fixincludes script from running. This is needed because
under normal circumstances the GCC installation will run the fixincludes
scripts which scans your system for header files that need to be fixed. Say
it finds Glibc header files. It will fix them and will end up in
$LFS/static/lib/gcc-lib/i686-pc-linux-gnu/3.2. Later on in chapter 6 you
will install Glibc which will install header files in /usr/include. Next
you will install other programs which will use Glibc headers. GCC will look
in /static/lib/gcc-lib before looking in /usr/include, whichhas the result
of Glibc header files from your host distribution being found and used which
are probably incompatible with the Glibc version actually in use on the LFS
system.</para>

<para><userinput>--prefix=/static:</userinput> This is NOT a typo. GCC hard
codes some paths while compiling and so we need to pass /static as the
prefix during ./configure. We pass the real install prefix during the
make install command later.</para>

<para><userinput>echo "#define HAVE_GAS_HIDDEN 1":</userinput>
This defines the .hidden assembler directive so that we don't build
a faulty Glibc later on.</para>

<para><userinput>make BOOT_LDFLAGS=-static:</userinput>
This is the equivalent to make LDFLAGS=-static as we use with other
packages to compile them statically.</para>

<para><userinput>ln -s gcc $LFS/static/bin/cc:</userinput> This
creates the $LFS/static/bin/gcc symlink, which some packages need.</para>

</sect2>