Re: [patches] Proposal for submission of dfp add-on to EGLIBC

[Jim Blandy <jimb@xxxxxxxxxxxxxxxx>]

Ryan, I have a question about the DFP add-on.

As Mark said, it's important for EGLIBC's purposes that embedded
developers be able to omit functionality they don't need, to save
space.  DFP packaged as an add-on, as it is now, is perfect in this
regard.  However, the add-on mechanism doesn't always lead to clean
design: add-ons can only override entire files, and sometimes
finer-grained changes are preferable.  I see the note on the DFP web
page about overriding vfprintf, math.h, and so on, so it seems that
the DFP implementation has run into this issue already.

Would it improve things to integrate DFP directly into the GLIBC
source tree?  If so, then EGLIBC's 'option group' mechanism would help
you do this while still allowing embedded developers to easily omit
decimal floating-point support if they don't need it.  The file
'EGLIBC.option-groups' in the top-level directory describes the option
group mechanism in more detail.

At the moment, there is no reflection of the selected option groups
into C preprocessor symbol definitions, but that's something we'd be
happy to add if it were helpful.  Option groups are a recent addition,
and we haven't needed that behavior yet.