[RFC] Update to current automake/autoconf/libtool versions (take 2)

[Klee Dienes]

On Sunday, January 12, 2003, at 12:13 PM, Zack Weinberg wrote:

> 1) I notice that you made the existing pseudo-AC_PROG_CC/CXX macros
>    work again with 2.5x; this is wrong.  Get rid of them entirely,
>    use the canonical AC_PROG_CC/CXX, and if they don't work right,
>    patch autoconf until they do.

The original theory was that I was trying to keep the diffs to a 
minimum, and that once the switch was flipped on 2.x, we could go back 
and make a lot of more interesting cleanups to the configure scripts.  
But I think you're right that my changes ended up complicated enough 
that I should just replace them with the modern versions; I'll do that.

> 2) Why did you disable the shared config.cache?  It speeds up 'make
>    configure' by an order of magnitude, especially on slow machines.

I didn't disable the config.cache in the top-level scripts; it's just 
that the new default is for autoconf to use a null cache file unless 
configured with '-C'.  A good portion of my patch is actually present 
solely to fix the use of a top-level cache file --- there were a number 
of places where whitespace triggered the "value changed between runs" 
checks in 2.5x.  I did disable the target config.cache, because there 
were places where things really were being run with different flags 
between runs (for example, the value of libstdcxx_flags varies by 
directory), and fixing that seemed beyond the scope of the initial 
conversion to 2.5x.