write recursive call

[François-Xavier Coudert]

> I don't recall whether I've seen that the runtime library has switchable
> standardization.

The runtime library can issue warnings and errors depending on the
standard and pedanticity selected at compile-time (options -std and
-pedantic). See notify_std in runtime/error.c for implementation and
grep for notify_std in the library sources to see how to use it.

PS: the framework to pass compile-time options to the library can
easily be extended to other options. Currently, only {-std,-pedantic}
and -ffpe-trap are used in the library.

FX