5.8. GCC-4.1.1 - Cross Compiler Final

#### Cross-Compiled Linux From Scratch - Version 1.0.0rc1-Sparc

### Chapter 5. Constructing Cross-Compile Tools

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# 5.8. GCC-4.1.1 - Cross Compiler Final

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

## 5.8.1. Installation of GCC Cross Compiler

The following patch fixes the searching of multilib dirs for specs file:

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

The following patches fixes an TLS build issue. For More details go to http://gcc.gnu.org/ml/gcc-patches/2006-02/msg00177.html:

    patch -Np1 -i ../gcc-4.1.1-sparc_tls-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-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

Change the StartFile Spec to point to the correct library location:

    echo "
    #undef STARTFILE_PREFIX_SPEC
    #define STARTFILE_PREFIX_SPEC \"/tools/lib/\"" >> gcc/config/sparc/linux.h

Now alter gcc's c preprocessor's default include search path to use `/tools` only:

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

Finally, disable `-B` in `configure`, so it doesn't pick up the host's header files:

    cp -v configure{,.orig}
    sed -e  '/FLAGS_FOR_TARGET.*\/lib\//s@-B[^ ]*/lib/@@g' configure.orig >configure

### 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

Prepare GCC for compilation:

    ../gcc-4.1.1/configure --prefix=/cross-tools \
        --target=${LFS_TARGET} --host=${LFS_HOST} --disable-multilib \
        --with-local-prefix=/tools --disable-nls --enable-shared \
        --enable-languages=c,c++ --enable-__cxa_atexit \
        --enable-c99 --enable-long-long --enable-threads=posix

The meaning of the new configure options:

`--enable-languages=c,c++`

  This option ensures that only the C and C++ compilers are built.

`--enable-__cxa_atexit`

  This option allows use of __cxa_atexit, rather than atexit, to register C++ destructors for local statics and global objects and is essential for fully standards-compliant handling of destructors. It also affects the C++ ABI and therefore results in C++ shared libraries and C++ programs that are interoperable with other Linux distributions.

`--enable-c99`

  Enable C99 support for C programs.

`--enable-long-long`

  Enables long long support in the compiler.

`--enable-threads=posix`

  This enables C++ exception handling for multi-threaded code.

Continue with compiling the package:

    make AS_FOR_TARGET="${LFS_TARGET}-as" \
        LD_FOR_TARGET="${LFS_TARGET}-ld"

Install the package:

    make install

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

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