[RFC PATCH]: enable building GMP/MPFR in local tree

[Mike Stump]

On Oct 8, 2006, at 1:42 PM, Kaveh R. GHAZI wrote:
> It turned out to be much easier than I thought to decipher the top  
> level
> machinery and get GMP/MPFR building inside the GCC tree. :-)

Some thoughts, if this configures and builds most (all?) of the time,  
then we are changing the portability profile of gcc to be min 
(gcc,mpfr,gmp) which could be < gcc.  If the user has installed a  
newer gmp/mpfr on the system, do we want to use the build tree  
version anyway?  Can we rm -rf gmp/mpfr from the source tree to  
disable the building of these?  I suspect all the GMPLIBS and GMPINC  
stuff in the configure script is dead after this (with this version  
of the patch), though, it is probably better to leave it in there for  
now.  What is the change in build time?  Do we want to always build  
it, or only when some languages (fortran?) are configured?  And  
lastly, do we want to do this in stage 3?