Re: enable long long and long double support in printf/scanf

[Jeff Johnston <jjohnstn at redhat dot com>]

Artem B. Bityuckiy wrote:
> Jeff Johnston wrote:
>
> > Patch with minor modifications checked in, thanks.  It was not 
> > necessary to alter acinclude.m4  since the new configuration options 
> > are designed to modify newlib.h.
>
> It seems to me this is some convention that I don't know. Please, can 
> you describe this issue in more details? Why some options are in 
> acinclude.m4 but some are directly in configure.in? Why for example 
> --enable-newlib-iconv isn't in acinclude.m4?

--enable-newlib-iconv can now be in configure.in since it uses newlib.h.  Since 
the only configuration required is to produce the correct newlib.h file, only 
the top newlib configuration is needed.  Newlib.h is relatively new in the 
scheme of things.  The historical way was to use compiler flags which required 
each subdirectory to do the same configuration tests to produce the set of 
compiler flags needed.  To do this we put the options in the top acinclude.m4 
and configure.host did the tests.  We then regenerated all the aclocal.m4 files 
in the lower directories.  Admittedly, things could have been set up differently 
to prevent the regeneration, but that is hindsight.

I didn't move existing options that could now be in configure.in because it will 
then require regenerating all of the aclocal.m4 files.  Since your patch was 
centered around 2 new configuration options and didn't require regeneration, I 
felt it was better to do a separate clean-up in the future.  It doesn't buy 
anything now anyway since the files have already been generated.

Flags might be useful in the future for options one might want to apply to a 
single directory but not the whole library.  For example, special debug flags. 
You could reconfigure in your build directory so that a particular subdirectory 
builds with special defines set.

> > Thus, the new options were placed in configure.in.  I modified 
> > configure.host to add some default option variables that various 
> > platforms can set as needed.  At the end of configure.host, a check is 
> > made to see if the configuration options are not set and if a default 
> > is specified.  This allows the user to override defaults with 
> > configuration options.
>
>
> Thanks.