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

[Gavin Smith]

On Sun, Mar 23, 2014 at 12:24 AM, John Spencer
<address@hidden> 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
>
> could be skipped and assumed to be always true.
>
If changing the configure scripts in question is an option, developers
could simply require C99 with AC_PROG_CC_C99 if they rely on many
characteristics of C99. autoscan suggests tests; some of these might
be unnecessary or included in broader tests.