[bc82645e] | 1 | <sect2><title> </title><para> </para></sect2>
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| 2 |
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| 3 | <sect2>
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[ab6f1859] | 4 | <title>Re-installation of GCC</title>
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| 5 |
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[62d0130] | 6 | <para>The tools required to test GCC and Binutils are installed now
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[2ea93a3] | 7 | (Expect, Tcl and DejaGnu). We can continue on rebuilding GCC and Binutils,
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[62d0130] | 8 | link them against the new Glibc, and test them properly. One thing to note,
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| 9 | however, is that these test suites are highly dependent on the features
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| 10 | supported by your host distribution. Most notably, a host distribution
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| 11 | which does not properly support the devpts filesystem will cause most of
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| 12 | these tests to fail.</para>
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| 13 |
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[297d8ee0] | 14 | <note><para>It's worth pointing out that the GCC test suite we run in this
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| 15 | section is considered not as critical as the one we run in Chapter 6.</para></note>
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[1f53626] | 16 |
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[db7ac2f] | 17 | <para>Unpack all three GCC tarballs (-core, -g++, and -testsuite) in one and the same working directory.
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[ab6f1859] | 18 | They will all unfold into a single <filename>gcc-&gcc-version;/</filename>
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| 19 | subdir.</para>
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[bc82645e] | 20 |
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[40b88c2] | 21 | <para>First correct one problem and make an essential adjustment:</para>
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[775a268] | 22 |
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[b19d5f96] | 23 | <para><screen><userinput>patch -Np1 -i ../gcc-&gcc-version;-no_fixincludes-2.patch
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[775a268] | 24 | patch -Np1 -i ../gcc-&gcc-specs-version;.patch</userinput></screen></para>
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| 25 |
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[be2dd91] | 26 | <para>The first patch disables the GCC "fixincludes" script. We mentioned this
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| 27 | briefly earlier, but a slightly more in-depth explanation of the fixincludes
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| 28 | process is warranted here. Under normal circumstances, the GCC fixincludes
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| 29 | script scans your system for header files that need to be fixed. It might find
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| 30 | that the Glibc header files on your host system need to be fixed, fix them and
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| 31 | put them in the GCC private include directory. Then, later on in Chapter 6,
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| 32 | after we've installed the newer Glibc, this private include directory would be
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| 33 | searched before the system include directory, resulting in GCC finding the
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| 34 | fixed headers from the host system, which would most likely not match the Glibc
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| 35 | version actually used for the LFS system.</para>
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| 36 |
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[dc19fb6] | 37 | <para>The last patch changes GCC's default location of the dynamic linker
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[76d113f] | 38 | (typically <filename>ld-linux.so.2</filename>). It also removes
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| 39 | <filename class="directory">/usr/include</filename> from GCC's include search
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| 40 | path. Patching now rather than adjusting the specs file after installation
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| 41 | ensures that our new dynamic linker gets used during the actual build of GCC.
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| 42 | That is, all the final (and temporary) binaries created during the build will
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| 43 | link against the new Glibc.</para>
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| 44 |
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| 45 | <important><para>These patches are <emphasis>critical</emphasis> in ensuring a
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| 46 | successful overall build. Do not forget to apply them.</para></important>
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[775a268] | 47 |
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| 48 | <para>Create a separate build directory again:</para>
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[bc82645e] | 49 |
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| 50 | <para><screen><userinput>mkdir ../gcc-build
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| 51 | cd ../gcc-build</userinput></screen></para>
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| 52 |
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[ab6f1859] | 53 | <para>Before starting to build GCC, remember to unset any environment
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| 54 | variables that override the default optimization flags.</para>
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| 55 |
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[775a268] | 56 | <para>Now prepare GCC to be compiled:</para>
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| 57 |
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[148bb04] | 58 | <para><screen><userinput>../gcc-&gcc-version;/configure --prefix=/tools \
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| 59 | --with-local-prefix=/tools \
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[6b2f69c] | 60 | --enable-clocale=gnu --enable-shared \
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[0939e573] | 61 | --enable-threads=posix --enable-__cxa_atexit \
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[775a268] | 62 | --enable-languages=c,c++</userinput></screen></para>
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| 63 |
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| 64 | <para>Compile the package:</para>
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| 65 |
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| 66 | <para><screen><userinput>make</userinput></screen></para>
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| 67 | <para>There is no need to use the <userinput>bootstrap</userinput> target now,
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| 68 | as the compiler we're using to compile this GCC has been built from the exact
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| 69 | same sources.</para>
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| 70 |
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[ab6f1859] | 71 | <para>Test the results:</para>
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[775a268] | 72 |
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| 73 | <para><screen><userinput>make -k check</userinput></screen></para>
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| 74 |
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| 75 | <para>The <userinput>-k</userinput> flag is used to make the test suite run
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| 76 | through to completion and not stop at the first failure. The GCC test suite is
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| 77 | very comprehensive and is almost guaranteed to generate a few failures. To get
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| 78 | a summary of the test suite results, run this:</para>
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| 79 |
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[0b5fd844] | 80 | <para><screen><userinput>../gcc-&gcc-version;/contrib/test_summary | less</userinput></screen></para>
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[775a268] | 81 |
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| 82 | <para>You can compare your results to those posted to the gcc-testresults
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| 83 | mailing list for similar configurations to your own. For an example of how
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[bef49bf] | 84 | current GCC-3.3.1 should look on i686-pc-linux-gnu, see
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| 85 | <ulink url="http://gcc.gnu.org/ml/gcc-testresults/2003-08/msg01612.html"/>.</para>
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[775a268] | 86 |
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| 87 | <para>Note that the results contain:</para>
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| 88 |
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| 89 | <screen>* 1 XPASS (unexpected pass) for g++
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[9e24a7d] | 90 | * 1 FAIL for g++
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| 91 | * 2 FAIL for gcc
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| 92 | * 26 XPASS's for libstdc++</screen>
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[775a268] | 93 |
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| 94 | <para>The unexpected pass for g++ is due to the use of
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| 95 | <userinput>--enable-__cxa_atexit</userinput>. Apparently not all platforms
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| 96 | supported by GCC have support for "__cxa_atexit" in their C libraries, so this
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| 97 | test is not always expected to pass.</para>
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| 98 |
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| 99 | <para>The 26 unexpected passes for libstdc++ are due to the use of
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| 100 | <userinput>--enable-clocale=gnu</userinput>, which is the correct choice on
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| 101 | Glibc-based systems of versions 2.2.5 and above. The underlying locale support
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| 102 | in the GNU C library is superior to that of the otherwise selected "generic"
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| 103 | model (which may be applicable if for instance you were using Newlibc, Sun-libc
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| 104 | or whatever libc). The libstdc++ test suite is apparently expecting the
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| 105 | "generic" model, hence those tests are not always expected to pass.</para>
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| 106 |
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| 107 | <para>And finally install the package:</para>
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| 108 |
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| 109 | <para><screen><userinput>make install</userinput></screen></para>
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[bc82645e] | 110 |
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| 111 | </sect2>
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| 112 |
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