From 1a915c7bf71fbcef0b7eeadba5e224a5886ea429 Mon Sep 17 00:00:00 2001
From: Wolfgang Bumiller <wry.git@bumiller.com>
Date: Wed, 24 Apr 2013 17:42:48 +0200
Subject: [PATCH] manpage: document and explain __FUNC__ and __NULL__

---
 doc/gmqcc.1 | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/doc/gmqcc.1 b/doc/gmqcc.1
index da79a5b..56728d1 100644
--- a/doc/gmqcc.1
+++ b/doc/gmqcc.1
@@ -351,15 +351,28 @@ __RANDOM__
 __RANDOM_LAST__
 __DATE__
 __TIME__
+__FUNC__
 .Ed
 .Pp
+Note that
+.Li __FUNC__
+is not actually a preprocessor macro, but is recognized by the parser
+even with the preprocessor disabled.
+.Pp
 Note that fteqcc also defines
 .Li __NULL__
-which is not implemented yet.
+which becomes the first global. Assigning it to a vector does not
+yield the same result as in gmqcc where
+.Li __NULL__
+is defined to
+.Li nil
 (See
 .Fl f Ns Cm untyped-nil
-about gmqcc's alternative to
-.Li __NULL__ Ns ).
+), which will cause the vector to be zero in all components. With fteqcc
+only the first component will be 0, while the other two will become
+the first to of the global return value. This behavior is odd and
+relying on it should be discouraged, and thus is not supported by
+gmqcc.
 .It Fl f Ns Cm relaxed-switch
 Allow switch cases to use non constant variables.
 .It Fl f Ns Cm short-logic