Flaws in GCC installation instructions

[Wakely]

​http://www.linuxfromscratch.org/lfs/view/development/chapter05/gcc-pass1.html lists the --disable-libmudflap option under "The meaning of the configure options:" but that option is not present in the command (and is meaningless for GCC 4.9)

​http://www.linuxfromscratch.org/lfs/view/development/chapter05/gcc-pass2.html says --enable-clocale=gnu is needed because "if the de_DE locale is not installed [...] the incorrect generic locale model may be selected". I don't believe that's true, the libstdc++ configure script doesn't check for de_DE, only the libstdc++ testsuite does (which cannot affect the ABI). --enable-clocale=gnu is the default for all linux systems so the option is not needed and the explanation is incorrect:

  # Probe for locale model to use if none specified.
  # Default to "generic".
  if test $enable_clocale_flag = auto; then
    case ${target_os} in
      linux* | gnu* | kfreebsd*-gnu | knetbsd*-gnu)
        enable_clocale_flag=gnu
        ;;

The GCC Pass 2 page also says for --enable-threads=posix that "This enables C++ exception handling for multi-threaded code." but that's not true, it chooses the thread model, but not anything to do with exceptions. The only supported models on GNU/Linux are "posix" and "single" and the default is "posix" so the option is not needed.

Also, --enable-__cxa_atexit is the default for linux (see gcc/config.gcc and gcc/configure.ac), so is also not needed.

[chris@…]

For the first point above, the text could be simplified by just saying something like "disable-lib* - Prevents GCC from building a number of libraries that are not needed right now".

Also, --enable-shared is not needed since it's on by default as well.

[bdubbs@…]

Fixed at revision 10698.