On Wed, Apr 26, 2017 at 11:32:21AM +0200, Andreas K. Huettel wrote > Except that "switching back" from gcc-5 to gcc-4 doesn't really work, > and that gcc-4 will happily use gcc-5 libraries, with unintended > consequences.
It can be done, but it takes a little work. I do a contributed build for Pale Moon using gcc 4.9.4 as per the developers' specs, and I use 5.4.0 for personal builds at home. This is done on a 32-bit CoentOS 6.5 chroot, in order to use an older gtk2 (long story). The native compiler is gcc 4.7.4. I build self-contained gcc 4.9.4 and 5.4.0 environments. Example follows, with gcc-4.9.4 going into $HOME/gcc494/ ####################################################################### # # Instructions adapted from https://gcc.gnu.org/wiki/InstallingGCC wget http://ftpmirror.gnu.org/gcc/gcc-4.9.4/gcc-4.9.4.tar.bz2 tar xjf gcc-4.9.4.tar.bz2 # # To get gmp, mpc, mpfr, and isl libs # You *MUST* run this script from the top-level GCC source dir cd gcc-4.9.4 contrib/download_prerequisites export CFLAGS="-O2 -march=native -mfpmath=sse -fomit-frame-pointer -pipe -fno-unwind-tables -fno-asynchronous-unwind-tables" export CXXFLAGS="${CFLAGS}" export MAKEOPTS="-j4" # # You *MUST NOT* run ./configure from the toplevel GCC source dir mkdir gcc-build && cd gcc-build ../configure --prefix=$HOME/gcc494 \ --disable-multilib \ --enable-libstdcxx-threads \ --enable-libstdcxx-time \ --enable-shared \ --enable-__cxa_atexit \ --disable-libunwind-exceptions \ --disable-libada make -j4 make install ####################################################################### So far, so good, but we also need to force invocations of "gcc" to use this version. The build script sources the following commands (and other build-specific stuff) before starting the compile... ####################################################################### export GCCX_ROOT=$HOME/gcc494 export PATH=$GCCX_ROOT/bin:$PATH export MANPATH=$GCCX_ROOT/share/man:MANPATH export INFOPATH=$GCCX_ROOT/share/info:$INFOPATH export LD_LIBRARY_PATH=$GCCX_ROOT/lib:$GCCX_ROOT/lib:$LD_LIBRARY_PATH export LD_RUN_PATH=$GCCX_ROOT/lib:$GCCX_ROOT/lib:$LD_RUN_PATH export LIBRARY_PATH=$GCCX_ROOT/lib:$GCCX_ROOT/lib:$LIBRARY_PATH export INCLUDE_PATH=$GCCX_ROOT/include:$INCLUDE_PATH export CPLUS_INCLUDE_PATH=$GCCX_ROOT/include:$CPLUS_INCLUDE_PATH export C_INCLUDE_PATH=$GCCX_ROOT/include:$C_INCLUDE_PATH ####################################################################### The include script to use gcc 5.4.0 differs in only the first line... ####################################################################### export GCCX_ROOT=$HOME/gcc540 ####################################################################### Would the various "export" commands work if inserted into make.conf? Actually, would they even need the "export " portion of the declaration? -- Walter Dnes <waltd...@waltdnes.org> I don't run "desktop environments"; I run useful applications
