5.7. Glibc-2.17

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

Приблизительное время сборки: 5.4 SBU
Требует свободного места на диске: 554 MB

5.7.1. Installation of Glibc

In some cases, particularly LFS 7.1, the rpc headers were not installed properly. Test to see if they are installed in the host system and install if they are not:

if [ ! -r /usr/include/rpc/types.h ]; then
  su -c 'mkdir -p /usr/include/rpc'
  su -c 'cp -v sunrpc/rpc/*.h /usr/include/rpc'
fi

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

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

Next, prepare Glibc for compilation:

../glibc-2.17/configure                             \
      --prefix=/tools                                 \
      --host=$LFS_TGT                                 \
      --build=$(../glibc-2.17/scripts/config.guess) \
      --disable-profile                               \
      --enable-kernel=2.6.25                          \
      --with-headers=/tools/include                   \
      libc_cv_forced_unwind=yes                       \
      libc_cv_ctors_header=yes                        \
      libc_cv_c_cleanup=yes

The meaning of the configure options:

--host=$LFS_TGT, --build=$(../glibc-2.17/scripts/config.guess)

The combined effect of these switches is that Glibc's build system configures itself to cross-compile, using the cross-linker and cross-compiler in /tools.

--disable-profile

This builds the libraries without profiling information. Omit this option if profiling on the temporary tools is necessary.

--enable-kernel=2.6.25

This tells Glibc to compile the library with support for 2.6.25 and later Linux kernels. Workarounds for older kernels are not enabled.

--with-headers=/tools/include

This tells Glibc to compile itself against the headers recently installed to the tools directory, so that it knows exactly what features the kernel has and can optimize itself accordingly.

libc_cv_forced_unwind=yes

The linker installed during Раздел 5.4, «Binutils-2.23.1 - Шаг 1» was cross-compiled and as such cannot be used until Glibc has been installed. This means that the configure test for force-unwind support will fail, as it relies on a working linker. The libc_cv_forced_unwind=yes variable is passed in order to inform configure that force-unwind support is available without it having to run the test.

libc_cv_c_cleanup=yes

Simlarly, we pass libc_cv_c_cleanup=yes through to the configure script so that the test is skipped and C cleanup handling support is configured.

libc_cv_ctors_header=yes

Simlarly, we pass libc_cv_ctors_header=yes through to the configure script so that the test is skipped and gcc constructor support is configured.

During this stage the following warning might appear:

configure: WARNING:
*** These auxiliary programs are missing or
*** incompatible versions: msgfmt
*** some features will be disabled.
*** Check the INSTALL file for required versions.

Отсутствующая или несовместимая утилита msgfmt обычно не приводит к проблемам. Эта программа является частью пакета Gettext, который должен предоставляться хост-системой.

Cкомпилируем пакет:

make

Этот пакет поставляется с набором тестов, однако, мы не cможем их запустить сейчас, поскольку еще не установили компилятор C++.

[Замечание]

Замечание

Для успешного выполнения тестирования также необходимо установить данные локалей. Данные локалей предоставляют системе информацию о том, в каком формате необходимо осуществлять ввод и вывод даты, времени и валют. Если тестирование (как и рекомендуется) не будет запускаться в этой главе, нет нужды устанавливать локали сейчас. Необходимые локали будут установлены в следующей главе. Чтобы все же установить локали Glibc, следуйте инструкциям из Раздел 6.9, «Glibc-2.17.»

Установим пакет:

make install
[Предостережение]

Предостережение

At this point, it is imperative to stop and ensure that the basic functions (compiling and linking) of the new toolchain are working as expected. To perform a sanity check, run the following commands:

echo 'main(){}' > dummy.c
$LFS_TGT-gcc dummy.c
readelf -l a.out | grep ': /tools'

If everything is working correctly, there should be no errors, and the output of the last command will be of the form:

[Requesting program interpreter: /tools/lib/ld-linux.so.2]

Note that /tools/lib, or /tools/lib64 for 64-bit machines appears as the prefix of the dynamic linker.

If the output is not shown as above or there was no output at all, then something is wrong. Investigate and retrace the steps to find out where the problem is and correct it. This issue must be resolved before continuing on.

Once all is well, clean up the test files:

rm -v dummy.c a.out
[Замечание]

Замечание

Building Binutils in the next section will serve as an additional check that the toolchain has been built properly. If Binutils fails to build, it is an indication that something has gone wrong with the previous Binutils, GCC, or Glibc installations.

Подробная информация об этом пакете расположена в Раздел 6.9.4, «Содержимое Glibc.»