mirror of
https://git.linuxfromscratch.org/lfs.git
synced 2025-01-20 05:57:43 +00:00
297d8ee004
git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@2866 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689
113 lines
5.3 KiB
XML
113 lines
5.3 KiB
XML
<sect2><title> </title><para> </para></sect2>
|
|
|
|
<sect2>
|
|
<title>Re-installation of GCC</title>
|
|
|
|
<para>The tools required to test GCC and Binutils are installed now
|
|
(Expect, Tcl and DejaGnu). We can continue on rebuilding GCC and Binutils,
|
|
link them against the new Glibc, and test them properly. One thing to note,
|
|
however, is that these test suites are highly dependent on the features
|
|
supported by your host distribution. Most notably, a host distribution
|
|
which does not properly support the devpts filesystem will cause most of
|
|
these tests to fail.</para>
|
|
|
|
<note><para>It's worth pointing out that the GCC test suite we run in this
|
|
section is considered not as critical as the one we run in Chapter 6.</para></note>
|
|
|
|
<para>Unpack all three GCC tarballs (-core, -g++, and -testsuite) in one and the same working directory.
|
|
They will all unfold into a single <filename>gcc-&gcc-version;/</filename>
|
|
subdir.</para>
|
|
|
|
<para>First correct one problem and make an essential adjustment:</para>
|
|
|
|
<para><screen><userinput>patch -Np1 -i ../gcc-&gcc-version;-no_fixincludes-2.patch
|
|
patch -Np1 -i ../gcc-&gcc-specs-version;.patch</userinput></screen></para>
|
|
|
|
<para>The first patch disables the GCC "fixincludes" script. We mentioned this
|
|
briefly earlier, but a slightly more in-depth explanation of the fixincludes
|
|
process is warranted here. Under normal circumstances, the GCC fixincludes
|
|
script scans your system for header files that need to be fixed. It might find
|
|
that the Glibc header files on your host system need to be fixed, fix them and
|
|
put them in the GCC private include directory. Then, later on in Chapter 6,
|
|
after we've installed the newer Glibc, this private include directory would be
|
|
searched before the system include directory, resulting in GCC finding the
|
|
fixed headers from the host system, which would most likely not match the Glibc
|
|
version actually used for the LFS system.</para>
|
|
|
|
<para>The last patch changes GCC's default location of the dynamic linker
|
|
(typically <filename>ld-linux.so.2</filename>). It also removes
|
|
<filename class="directory">/usr/include</filename> from GCC's include search
|
|
path. Patching now rather than adjusting the specs file after installation
|
|
ensures that our new dynamic linker gets used during the actual build of GCC.
|
|
That is, all the final (and temporary) binaries created during the build will
|
|
link against the new Glibc.</para>
|
|
|
|
<important><para>These patches are <emphasis>critical</emphasis> in ensuring a
|
|
successful overall build. Do not forget to apply them.</para></important>
|
|
|
|
<para>Create a separate build directory again:</para>
|
|
|
|
<para><screen><userinput>mkdir ../gcc-build
|
|
cd ../gcc-build</userinput></screen></para>
|
|
|
|
<para>Before starting to build GCC, remember to unset any environment
|
|
variables that override the default optimization flags.</para>
|
|
|
|
<para>Now prepare GCC to be compiled:</para>
|
|
|
|
<para><screen><userinput>../gcc-&gcc-version;/configure --prefix=/tools \
|
|
--with-local-prefix=/tools \
|
|
--enable-clocale=gnu --enable-shared \
|
|
--enable-threads=posix --enable-__cxa_atexit \
|
|
--enable-languages=c,c++</userinput></screen></para>
|
|
|
|
<para>Compile the package:</para>
|
|
|
|
<para><screen><userinput>make</userinput></screen></para>
|
|
<para>There is no need to use the <userinput>bootstrap</userinput> target now,
|
|
as the compiler we're using to compile this GCC has been built from the exact
|
|
same sources.</para>
|
|
|
|
<para>Test the results:</para>
|
|
|
|
<para><screen><userinput>make -k check</userinput></screen></para>
|
|
|
|
<para>The <userinput>-k</userinput> 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 get
|
|
a summary of the test suite results, run this:</para>
|
|
|
|
<para><screen><userinput>../gcc-&gcc-version;/contrib/test_summary | less</userinput></screen></para>
|
|
|
|
<para>You can compare your results to those posted to the gcc-testresults
|
|
mailing list for similar configurations to your own. For an example of how
|
|
current GCC-3.3.1 should look on i686-pc-linux-gnu, see
|
|
<ulink url="http://gcc.gnu.org/ml/gcc-testresults/2003-08/msg01612.html"/>.</para>
|
|
|
|
<para>Note that the results contain:</para>
|
|
|
|
<screen>* 1 XPASS (unexpected pass) for g++
|
|
* 1 FAIL for g++
|
|
* 2 FAIL for gcc
|
|
* 26 XPASS's for libstdc++</screen>
|
|
|
|
<para>The unexpected pass for g++ is due to the use of
|
|
<userinput>--enable-__cxa_atexit</userinput>. Apparently not all platforms
|
|
supported by GCC have support for "__cxa_atexit" in their C libraries, so this
|
|
test is not always expected to pass.</para>
|
|
|
|
<para>The 26 unexpected passes for libstdc++ are due to the use of
|
|
<userinput>--enable-clocale=gnu</userinput>, which is the correct choice on
|
|
Glibc-based systems of versions 2.2.5 and above. The underlying locale support
|
|
in the GNU C library is superior to that of the otherwise selected "generic"
|
|
model (which may be applicable if for instance you were using Newlibc, Sun-libc
|
|
or whatever libc). The libstdc++ test suite is apparently expecting the
|
|
"generic" model, hence those tests are not always expected to pass.</para>
|
|
|
|
<para>And finally install the package:</para>
|
|
|
|
<para><screen><userinput>make install</userinput></screen></para>
|
|
|
|
</sect2>
|
|
|