The GCC package contains the GNU compiler collection, which includes the C and C++ compilers.
Approximate build time: 11.7 SBU Required disk space: 294 MB
GCC installation depends on: Bash, Binutils, Coreutils, Diffutils, Findutils, Gawk, Gettext, Glibc, Grep, Make, Perl, Sed, Texinfo.
This package is known to behave badly when you have changed its default optimization flags (including the -march and -mcpu options). Therefore, if you have defined any environment variables that override default optimizations, such as CFLAGS and CXXFLAGS, we recommend un-setting or modifying them when building GCC.
Unpack the GCC-core and the GCC-g++ tarball -- they will unfold into the same directory. You should likewise extract the GCC-testsuite package. The full GCC package contains even more compilers. Instructions for building these can be found at http://www.linuxfromscratch.org/blfs/view/stable/general/gcc.html.
First apply only the No-Fixincludes patch (and not the Specs patch) also used in the previous chapter:
patch -Np1 -i ../gcc-3.3.3-no_fixincludes-1.patch
Now apply a sed substitution that will suppress the installation of libiberty.a. We want to use the version of libiberty.a provided by Binutils:
sed -i 's/install_to_$(INSTALL_DEST) //' libiberty/Makefile.in
The GCC documentation recommends building GCC outside of the source directory in a dedicated build directory:
mkdir ../gcc-build cd ../gcc-build
Now prepare GCC for compilation:
../gcc-3.3.3/configure --prefix=/usr \ --enable-shared --enable-threads=posix \ --enable-__cxa_atexit --enable-clocale=gnu \ --enable-languages=c,c++
Compile the package:
make
The test suite for GCC in this section is considered critical. Our advice is to not skip it under any circumstance.
Test the results, but don't stop at errors (you'll remember the few known ones):
make -k check
The test suite notes from the section called “GCC-3.3.3 - Pass 2” are still very much appropriate here. Be sure to refer back there should you have any doubts.
Now install the package:
make install
Some packages expect the C PreProcessor to be installed in the /lib directory. To support those packages, create this symlink:
ln -s ../usr/bin/cpp /lib
Many packages use the name cc to call the C compiler. To satisfy those packages, create a symlink:
ln -s gcc /usr/bin/cc
At this point it is strongly recommended to repeat the sanity check we performed earlier in this chapter. Refer back to the section called “Re-adjusting the toolchain” and repeat the check. If the results are wrong, then most likely you erroneously applied the GCC Specs patch from Chapter 5.
Installed programs: c++, cc (link to gcc), cc1, cc1plus, collect2, cpp, g++, gcc, gccbug, and gcov
Installed libraries: libgcc.a, libgcc_eh.a, libgcc_s.so, libstdc++.[a,so] and libsupc++.a
cpp is the C preprocessor. It is used by the compiler to have the #include and #define and such statements expanded in the source files.
gcc is the C compiler. It is used to translate the source code of a program into assembly code.
gccbug is a shell script used to help create good bug reports.
gcov is a coverage testing tool. It is used to analyze programs to find out where optimizations will have the most effect.
libgcc* contains run-time support for gcc.
libstdc++ is the standard C++ library. It contains many frequently-used functions.
libsupc++ provides supporting routines for the c++ programming language.