10.7. Glibc-2.19 32 Bit Libraries

The Glibc package contains the main C library. This library provides the basic routines for allocating memory, searching directories, opening and closing files, reading and writing files, string handling, pattern matching, arithmetic, and so on.

10.7.1. Installation of Glibc



Some packages outside of CLFS suggest installing GNU libiconv in order to translate data from one encoding to another. The project's home page (http://www.gnu.org/software/libiconv/) says “This library provides an iconv() implementation, for use on systems which don't have one, or whose implementation cannot convert from/to Unicode.” Glibc provides an iconv() implementation and can convert from/to Unicode, therefore libiconv is not required on a CLFS system.

At the end of the installation, the build system will run a sanity test to make sure everything installed properly. This script performs its tests by attempting to compile test programs against certain libraries. However it does not specify the path to ld.so, and our toolchain is still configured to use the one in /tools. The following set of commands will force the script to use the complete path of the new ld.so that was just installed:

LINKER=$(readelf -l /tools/bin/bash | sed -n 's@.*interpret.*/tools\(.*\)]$@\1@p')
sed -i "s|libs -o|libs -L/usr/lib -Wl,-dynamic-linker=${LINKER} -o|" \
unset LINKER

The Glibc build system is self-contained and will install perfectly, even though the compiler specs file and linker are still pointing at /tools. The specs and linker cannot be adjusted before the Glibc install because the Glibc Autoconf tests would give false results and defeat the goal of achieving a clean build.

The powerpc (32) architecture is expected to fail the check-textrel tests because it cannot protect some elf segments in shared libraries from being executable and writable. Using the default 64-bit compiler means the test runs as __powerpc64__ which is not expected to fail. The problem only exists in 32-bit, the 64-bit ABI allows the segments to be protected.

Other distributions alter gcc to default to 32-bits and so do not see this failure. Whether they then test correctly on 64-bit libraries is not our problem.

Force the test to use the 32-bit compiler with the following sed :

sed -i "s/\(^check-textrel-CFLAGS = \)/\1 ${BUILD32} /" elf/Makefile

Apply the following sed so the tzselect script works properly:

sed -i 's/\\$$(pwd)/`pwd`/' timezone/Makefile

The Glibc documentation recommends building Glibc outside of the source directory in a dedicated build directory:

mkdir -v ../glibc-build
cd ../glibc-build

Prepare Glibc for compilation:

CC="gcc ${BUILD32}" CXX="g++ ${BUILD32}" \
    ../glibc-2.19/configure --prefix=/usr \
    --disable-profile --enable-kernel=2.6.32 \
    --libexecdir=/usr/lib/glibc --host=${CLFS_TARGET32} \

The meaning of the new configure option:


This changes the location for hard links to the getconf utility from their default of /usr/libexec to /usr/lib/glibc.

Compile the package:



Due to Glibc's critical role in a properly functioning system, the CLFS developers strongly recommend running the testsuite.

In multilib, we tend to think that compiling for ${CLFS_TARGET32} is not cross-compiling. Glibc takes the traditional view that if you are building for a different host then you are cross-compiling, so you won't be running the tests and therefore you don't need the locale files. When we run the tests, many will fail if the locale files are missing. The following sed allows these tests to succeed:

sed -i '/cross-compiling/s@ifeq@ifneq@g' ../glibc-2.19/localedata/Makefile

Use the following commands to run the test suite and output any test failures:

make -k check 2>&1 | tee glibc-check-log; grep Error glibc-check-log

The Glibc test suite is highly dependent on certain functions of the host system, in particular the kernel. The posix/annexc and conform/run-conformtest tests normally fail and you should see Error 1 (ignored) in the output. Apart from this, the Glibc test suite is always expected to pass. However, in certain circumstances, some failures are unavoidable. If a test fails because of a missing program (or missing symbolic link), or a segfault, you will see an error code greater than 127 and the details will be in the log. More commonly, tests will fail with Error 2 - for these, the contents of the corresponding .out file, e.g. posix/annexc.out may be informative. Here is a list of the most common issues:

  • The nptl/tst-clock2, nptl/tst-attr3, tst/tst-cputimer1, and rt/tst-cpuclock2 tests have been known to fail. The reason is not completely understood, but indications are that minor timing issues can trigger these failures.

  • The math tests sometimes fail. Certain optimization settings are known to be a factor here.

  • If you have mounted the CLFS partition with the noatime option, the atime test will fail. As mentioned in Section 2.5, “Mounting the New Partition”, do not use the noatime option while building CLFS.

  • When running on older and slower hardware, some tests can fail because of test timeouts being exceeded. Modifying the make check command to set a TIMEOUTFACTOR is reported to help eliminate these errors (e.g. TIMEOUTFACTOR=16 make -k check).

  • posix/tst-getaddrinfo4 will always fail due to not having a network connection when the test is run.

Though it is a harmless message, the install stage of Glibc will complain about the absence of /etc/ld.so.conf. Prevent this warning with:

touch /etc/ld.so.conf

Install the package, and remove unneeded files from /usr/include/rpcsvc:

make install &&
rm -v /usr/include/rpcsvc/*.x

Details on this package are located in Section 10.8.5, “Contents of Glibc.”