6.4. GCC-4.1.1

#### Cross-Compiled Linux From Scratch - Version 1.0.0rc2-x86_64-Pure64

### Chapter 6. Constructing a Temporary System

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# 6.4. GCC-4.1.1

The GCC package contains the GNU compiler collection, which includes the C and C++ compilers.

## 6.4.1. Installation of GCC

The following patch fixes the searching of multilib dirs for specs file. The patch standardizes the gcc drivers path iteration functions, ensuring multilib directories are searched in the correct order. This fixes various issues, most noticably with libtool on multilib systems:

    patch -Np1 -i ../gcc-4.1.1-PR20425-1.patch

Make a couple of essential adjustments to the specs file to ensure GCC uses our build environment:

    patch -Np1 -i ../gcc-4.1.1-pure64_specs-1.patch

To make sure that a couple of tools use the proper syntax, apply the following patch:

    patch -Np1 -i ../gcc-4.1.1-posix-1.patch

The following patch ensures that gcc does not search the `/usr` directory for `libgcc_s.so` when cross-compiling:

    patch -Np1 -i ../gcc-4.1.1-cross_search_paths-1.patch

Now we will change cpp's search path not to look in `/usr/include`:

    cp -v gcc/cppdefault.c{,.orig}
    sed -e '/#define STANDARD_INCLUDE_DIR/s@"/usr/include"@0@g' \
        gcc/cppdefault.c.orig > gcc/cppdefault.c

Also, we need to set the directory searched by the fixincludes process for system headers, so it won't look at the host's headers:

    cp -v gcc/Makefile.in{,.orig}
    sed -e 's@\(^NATIVE_SYSTEM_HEADER_DIR =\).*@\1 /tools/include@g' \
        gcc/Makefile.in.orig > gcc/Makefile.in

When searching for the multilibs, force the build to use the results of `--print-multi-lib` from our cross-compiler, not the native compiler gcc builds now:

    cp -v gcc/Makefile.in{,.orig2}
    sed -e "/MULTILIBS/s@\$(GCC_FOR_TARGET)@/cross-tools/bin/${CC}@g" \
       gcc/Makefile.in.orig2 > gcc/Makefile.in

### Important

The above patches and sed's are critical in ensuring a successful overall build. Do not forget to apply them.

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

    mkdir -v ../gcc-build
    cd ../gcc-build

Before starting to build GCC, remember to unset any environment variables that override the default optimization flags.

Prepare GCC for compilation:

    CC="${CC} ${BUILD64}" CXX="${CXX} ${BUILD64}" \
        ../gcc-4.1.1/configure --prefix=/tools --disable-multilib \
        --build=${CLFS_HOST} --host=${CLFS_TARGET} --target=${CLFS_TARGET} \
        --libexecdir=/tools/lib --with-local-prefix=/tools --enable-long-long \
        --enable-c99 --enable-shared --enable-threads=posix --enable-__cxa_atexit \
        --disable-nls --enable-languages=c,c++ --disable-libstdcxx-pch

The meaning of the new configure options:

`CXX="${CXX} ${BUILD64}"`

  This forces the C++ compiler to use our Build 64 FLAGS.

`--disable-libstdcxx-pch`

  Do not build the pre-compiled header (PCH) for `libstdc++`. It takes up a lot of space, and we have no use for it.

Compile the package:

    make AS_FOR_TARGET="${AS}" \
        LD_FOR_TARGET="${LD}"

Install the package:

    make install

Now we copy the files that are placed in `/tools/lib64` to `/tools/lib`. We also delete the /tools/lib64 directory:

    cp -va /tools/lib64/* /tools/lib
    rm -rvf /tools/lib64

Many packages use the name cc to call the C compiler. To satisfy those packages, create a symlink:

    ln -sv gcc /tools/bin/cc

Details on this package are located in Section 10.9.2, “Contents of GCC.”

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