Linux From Scratch - Version SVN-20150308

Chapter 5. Constructing a Temporary System

5.8. Libstdc++-4.9.2

Libstdc++ is the standard C++ library. It is needed for the correct operation of the g++ compiler.

Approximate build time: 0.3 SBU
Required disk space: 798 MB

5.8.1. Installation of Target Libstdc++

[Note]

Note

Libstdc++ is part of the GCC sources. You should first unpack the GCC tarball and change to the gcc-4.9.2 directory.

Create a directory for Libstdc++ and enter it: 

mkdir -pv ../gcc-build
cd ../gcc-build

5.8.2. 32-bit Installation

Prepare Libstdc++ for 32-bit compilation: 

../gcc-4.9.2/libstdc++-v3/configure \
    --host=$LFS_TGT32               \
    --prefix=/tools                 \
    --libdir=/tools/lib32           \
    --disable-multilib              \
    --disable-shared                \
    --disable-nls                   \
    --disable-libstdcxx-threads     \
    --disable-libstdcxx-pch         \
    --with-gxx-include-dir=/tools/$LFS_TGT/include/c++/4.9.2 \
    CC="$LFS_TGT-gcc -m32"          \
    CXX="$LFS_TGT-g++ -m32"

The meaning of the configure options:

--host=...

Indicates to use the cross compiler we have just built instead of the one in /usr/bin.

--libdir=/tools/lib32

Installs the 32-bit library files to /tools/lib32.

--disable-libstdcxx-threads

Since we have not built the thread C library, the C++ one cannot be built as well.

--disable-libstdcxx-pch

This switch prevents the installation of precompiled include files, which are not needed at this stage.

--with-gxx-include-dir=/tools/$LFS_TGT/include/c++/4.9.2

This is the location where the standard include files are searched by the C++ compiler. In a normal build, this information is automatically passed to the Libstdc++ configure options from the toplevel directory. In our case, this information must be explicitly given.

CC="$LFS_TGT-gcc -m32", CXX="$LFS_TGT-g++ -m32"

Ensures that the GCC compiler builds 32-bit libraries.

Compile libstdc++ by running: 

make

Install the library: 

make install

Clean up the build folder before moving on to the next platform: 

rm -fr *

5.8.3. x32 ABI Installation

Prepare Libstdc++ for x32 ABI compilation: 

../gcc-4.9.2/libstdc++-v3/configure \
    --host=$LFS_TGTX32              \
    --prefix=/tools                 \
    --libdir=/tools/libx32          \
    --disable-multilib              \
    --disable-shared                \
    --disable-nls                   \
    --disable-libstdcxx-threads     \
    --disable-libstdcxx-pch         \
    --with-gxx-include-dir=/tools/$LFS_TGT/include/c++/4.9.2 \
    CC="$LFS_TGT-gcc -mx32"         \
    CXX="$LFS_TGT-g++ -mx32"

The meaning of the configure options:

--host=...

Indicates to use the cross compiler we have just built instead of the one in /usr/bin.

--libdir=/tools/libx32

Installs the 32-bit library files to /tools/libx32.

--disable-libstdcxx-threads

Since we have not built the thread C library, the C++ one cannot be built as well.

--disable-libstdcxx-pch

This switch prevents the installation of precompiled include files, which are not needed at this stage.

--with-gxx-include-dir=/tools/$LFS_TGT/include/c++/4.9.2

This is the location where the standard include files are searched by the C++ compiler. In a normal build, this information is automatically passed to the Libstdc++ configure options from the toplevel directory. In our case, this information must be explicitly given.

CC="$LFS_TGT-gcc -mx32", CXX="$LFS_TGT-g++ -mx32"

Ensures that the GCC compiler builds x32 ABI libraries.

Compile libstdc++ by running: 

make

Install the library: 

make install

Clean up the build folder before moving on to the next platform: 

rm -fr *

5.8.4. 64-bit Installation

Prepare Libstdc++ for 64-bit compilation: 

../gcc-4.9.2/libstdc++-v3/configure \
    --host=$LFS_TGT                 \
    --prefix=/tools                 \
    --disable-multilib              \
    --disable-shared                \
    --disable-nls                   \
    --disable-libstdcxx-threads     \
    --disable-libstdcxx-pch         \
    --with-gxx-include-dir=/tools/$LFS_TGT/include/c++/4.9.2

The meaning of the configure options:

--host=...

Indicates to use the cross compiler we have just built instead of the one in /usr/bin.

--disable-libstdcxx-threads

Since we have not built the thread C library, the C++ one cannot be built as well.

--disable-libstdcxx-pch

This switch prevents the installation of precompiled include files, which are not needed at this stage.

--with-gxx-include-dir=/tools/$LFS_TGT/include/c++/4.9.2

This is the location where the standard include files are searched by the C++ compiler. In a normal build, this information is automatically passed to the Libstdc++ configure options from the toplevel directory. In our case, this information must be explicitly given.

Compile libstdc++ by running: 

make

Install the library: 

make install

Details on this package are located in Section 6.19.2, “Contents of GCC.”