Re: Updating top-level autoconf to 2.59

[Ian Lance Taylor <iant at google dot com>]

"Joseph S. Myers" <joseph@codesourcery.com> writes:

> * If you want to build an explicitly cross tool despite host == target, or 
> act like you are cross compiling despite build == host, or build a native 
> tool (i.e. one using the native directory layout and installed as plain 
> "gcc") despite host != target, or act like you aren't cross compiling (so 
> can run execute tests for $host) despite build != host, these should be 
> determined by explicit configure options; not by which of build, host and 
> target where specified explicitly and which were defaulted.  (And not by 
> older autoconf's experiments to see if it can execute a program built for 
> the host.)

I completely agree that this is how it should work.  Unfortunately,
this is not how autoconf {2.x,x>13} works.  I don't agree with a
number of the decisions made by the autoconf maintainers.  However, I
do think that as long we use autoconf, there is some benefit to be
gained by following autoconf's default behaviour.

Changing how we invoke configure is less of a change than requiring
MPFR, and my opinion is that on balance we will be better off changing
than forging our own path.

Ian