Details on this package are located in Section 8.29.2, “Contents of GCC.”
Libstdc++ is the standard C++ library. It is needed to compile C++ code (part of GCC is written in C++), but we had to defer its installation when we built gcc-pass1 because Libstdc++ depends on Glibc, which was not yet available in the target directory.
Libstdc++ is part of the GCC
sources. You should first unpack the GCC tarball and change to
the gcc-14.2.0
directory.
Create a separate build directory for Libstdc++ and enter it:
mkdir -v build cd build
Prepare Libstdc++ for compilation:
../libstdc++-v3/configure \ --host=$LFS_TGT \ --build=$(../config.guess) \ --prefix=/usr \ --disable-multilib \ --disable-nls \ --disable-libstdcxx-pch \ --with-gxx-include-dir=/tools/$LFS_TGT/include/c++/14.2.0
The meaning of the configure options:
--host=...
Specifies that the cross-compiler we have just built should
be used instead of the one in /usr/bin
.
--disable-libstdcxx-pch
This switch prevents the installation of precompiled include files, which are not needed at this stage.
--with-gxx-include-dir=/tools/$LFS_TGT/include/c++/14.2.0
This specifies the installation directory for include files.
Because Libstdc++ is the standard C++ library for LFS, this
directory should match the location where the C++ compiler
($LFS_TGT-g++)
would search for the standard C++ include files. In a normal
build, this information is automatically passed to the
Libstdc++ configure options from the
top level directory. In our case, this information must be
explicitly given. The C++ compiler will prepend the sysroot
path $LFS
(specified when
building GCC-pass1) to the include file search path, so it
will actually search in $LFS/tools/$LFS_TGT/include/c++/14.2.0
. The
combination of the DESTDIR
variable (in the
make install
command below) and this switch causes the headers to be
installed there.
Compile Libstdc++ by running:
make
Install the library:
make DESTDIR=$LFS install
Remove the libtool archive files because they are harmful for cross-compilation:
rm -v $LFS/usr/lib/lib{stdc++{,exp,fs},supc++}.la
Details on this package are located in Section 8.29.2, “Contents of GCC.”