Re: Patch to improve computations of gxx_include_dir and gcc_tooldir

[Jeffrey A Law <law at hurl dot cygnus dot com>]

  In message <14041.2658.836711.334154@saturn.hollstein.net>you write:
  > On Thu, 25 February 1999, 15:24:58, nickc@cygnus.com wrote:

  > STOP, this will break building packages like .rpm's or .deb's!
  > Passing down 'gxx_include_dir' by the top level Makefile had been
  > added for two purposes:
Unfortunately, passing down gxx_include_dir loses in a big way becuase it's
impossible to build a relative path to access the header files -- which
in turn makes it impossible to move toolchains around.

Basically gcc and libstdc++ use that variable in two different ways -- one
to install header files (libstdc++) one to find header files (gcc).  While
they need to agree in the sense that they ultimately must resolve to the same
directory when building the compiler, it is desirable if they can resolve to
different directories when folks actually use the compiler.

Basically we made a mistake when using gxx_include_dir as an override for
gcc's subdirectory.  We need to fix that mistake.

This is also part of the motivation behind revamping the configure/build
subsystem.  These hidden dependencies are a bitch.

jeff