Details on this package are located in Section 10.16.2, “Contents of GCC.”
The GCC package contains the GNU compiler collection, which includes the C and C++ compilers.
The following patch contains a number of updates to the 4.8.1 branch by the GCC developers:
patch -Np1 -i ../gcc-4.8.1-branch_update-3.patch
Make a couple of essential adjustments to the specs file to ensure GCC uses our build
environment:
patch -Np1 -i ../gcc-4.8.1-pure64_specs-1.patch
Change the StartFile Spec so that GCC looks in /tools:
echo -en '\n#undef STANDARD_STARTFILE_PREFIX_1\n#define STANDARD_STARTFILE_PREFIX_1 "/tools/lib/"\n' >> gcc/config/rs6000/sysv4.h echo -en '\n#undef STANDARD_STARTFILE_PREFIX_2\n#define STANDARD_STARTFILE_PREFIX_2 ""\n' >> gcc/config/rs6000/sysv4.h
We will create a dummy limits.h so
the build will not use the one provided by the host distro:
touch /tools/include/limits.h
The GCC documentation recommends building GCC outside of the source directory in a dedicated build directory:
mkdir -v ../gcc-build cd ../gcc-build
Prepare GCC for compilation:
AR=ar LDFLAGS="-Wl,-rpath,/cross-tools/lib" \
../gcc-4.8.1/configure --prefix=/cross-tools \
--build=${CLFS_HOST} --host=${CLFS_HOST} --target=${CLFS_TARGET} \
--with-sysroot=${CLFS} --with-local-prefix=/tools \
--with-native-system-header-dir=/tools/include --disable-nls \
--disable-shared --with-mpfr=/cross-tools --with-gmp=/cross-tools \
--with-isl=/cross-tools --with-cloog=/cross-tools --with-mpc=/cross-tools \
--without-headers --with-newlib --disable-decimal-float --disable-libgomp \
--disable-libmudflap --disable-libssp --disable-threads --disable-multilib \
--disable-libatomic --disable-libitm --disable-libsanitizer \
--disable-libquadmath --disable-target-libiberty --disable-target-zlib \
--with-system-zlib --enable-cloog-backend=isl --disable-isl-version-check \
--enable-languages=c --enable-checking=release
The meaning of the new configure options:
--with-sysroot=${CLFS}
Tells GCC to consider ${CLFS} as the root file system.
--with-local-prefix=/tools
The purpose of this switch is to remove /usr/local/include from gcc's include search path.
This is not absolutely essential, however, it helps to
minimize the influence of the host system.
--with-native-system-headers-dir=/tools/include
This switch ensures that GCC will search for the system
headers in /tools/include and
that host system headers will not be searched.
--disable-nls
This disables internationalization as i18n is not needed for the cross-compile tools.
--without-headers
Disables GCC from using the target's Libc when cross compiling.
--with-newlib
Tells GCC that the target libc will use 'newlib'.
--disable-decimal-float
Disables support for the C decimal floating point extension.
--disable-libgomp
Disables the creation of runtime libraries used by GOMP.
--disable-libmudflap
Disables the creation of runtime libaries used by libmudflap.
--disable-libssp
Disables the use of Stack Smashing Protection for runtime libraries.
--disable-threads
This will prevent GCC from looking for the multi-thread include files, since they haven't been created for this architecture yet. GCC will be able to find the multi-thread information after the Glibc headers are created.
--disable-libatomic
The atomic library isn't needed at this time.
--disable-libitm
The itm library isn't neeeded at this tiem.
--disable-libsanitizer
The sanitizer library isn't needed at this time.
--disable-libquadmath
The quadmath library isn't needed at this time.
--enable-languages=c
This option ensures that only the C compiler is built.
--enable-checking=release
This option selects the complexity of the internal consistency checks and adds error checking within the compiler.
Continue with compiling the package:
make all-gcc all-target-libgcc
The meaning of the new make options:
all-gcc
all-target-libgcc
Compiles only the parts of GCC that are needed at this time, rather than the full package.
Install the package:
make install-gcc install-target-libgcc
Details on this package are located in Section 10.16.2, “Contents of GCC.”