_NETBSD_SOURCE as this makes cross building from older/newer versions of
NetBSD harder, not easier (and also makes the resulting tools 'different')
Wrap all required code with the inclusion of nbtool_config.h, attempt to
only use POSIX code in all places (or when reasonable test w. configure and
provide definitions: ala u_int, etc).
Reviewed by lukem. Tested on FreeBSD 4.9, Redhat Linux ES3, NetBSD 1.6.2 x86
NetBSD current (x86 and amd64) and Solaris 9.
Fixes PR's: PR#17762 PR#25944
* Provide some GNUisms as extensions.
* Provide dynamically growable string space.
* Make define(defn(foo)) work correctly for builtins.
(The current version is supposed to be capable of satisfying autoconf.)
All still relevant NetBSD changes have been preserved in this version, and
formatting and style fixes have been applied in various places.
Thanks to Masao Uebayashi <uebayasi@soum.co.jp> for pointing this out.
in `The M4 Macro Processor', by Kernighan and Ritchie.
* `|' and `||' are both logical or. There is no binary or.
* `&' and `&&' are both logical and. There is no binary and.
* `!' has a much higher precedence.
* The equal and relation operators have the same precedence.
* `**' is implemented, and `^' is for exponentation (not xor).
* Unary `+' in implemented.
I've coded exponentiation to return what appears to be the same results
that other versions of m4 return.