Re: configure speedup proposal: add --assume-c99 and --assume-posix2008 flags

[Ralf Corsepius]

On 03/23/2014 01:24 AM, John Spencer wrote:
> there are many configure scripts out there that still check for things
> that are standard since at least 10 years, and doing this extensively
> and over and over (people building software themselves usually build
> more than one package) consumes a lot of time (especially due to the
> non-parallel nature of configure scripts).
> often configure scripts take longer to finish than compiling the source
> code itself on decent machines with multiple cpu cores.
>
> having an option like --assume-c99 could provide a shortcut so all
> checks like
>
> - have stdint.h
> - have snprintf()
> - etc
>
> and for posix
> - sizeof int == 4
> - have select()
> - etc

These assumptions are unsafe, esp. on non-mainstream architectures/OSes, 
which only partially implement c99.

E.g. it's not that uncommon to find toolchains for embedded platforms 
which implement most of C99, but with sizeof int != 4 or without "select()".

Ralf