m4 requirement (was: prerequisites page)

[Gerald Pfeifer]

Todd,

On Wed, 19 May 2010, Todd Rinaldo wrote:
> I'm writing to report a discrepancy in 
> http://gcc.gnu.org/install/prerequisites.html
> 
> I just discovered that if gmp is boot strapped during gcc build and an 
> older m4 exists, when gmp calls flex, it will fail during configure 
> with:
> 
> checking for flex... flex
> checking lex output file root... configure: error: cannot find output from flex; giving up
> 
> I mention this because the prerequisites page specifies m4 as optional 
> if you're just building gcc. m4 appears to have a minimal requirement if 
> gmp is being boot strapped.

thanks for the report, Todd.  You mention m4, yet the output you show
is around flex?  

I can update our documentation, but need more details and confirmation
by the respective GCC maintainers on what exactly to adjust.

Gerald