I was looking at a backport of the current linux.opt, and got confused
by the chain of three Negative()s. I was thinking that saying
"A is Negative(B)" was equivalent to saying A == !B.
This patch is an attempt to clarify the documentation. Tested with
"make doc", "make html" and "make pdf". OK to install?
Richard
gcc/
* doc/options.texi (Negative): Explicitly mention that the
Negative chain must be circular.
Index: gcc/doc/options.texi
===================================================================
--- gcc/doc/options.texi 2011-04-07 09:23:22.000000000 +0100
+++ gcc/doc/options.texi 2011-04-13 13:42:24.000000000 +0100
@@ -222,6 +222,13 @@ the option name with the leading ``-'' r
propagate through the @code{Negative} property of the option to be
turned off.
+As a consequence, if you have a group of mutually-exclusive
+options, their @code{Negative} properties should form a circular chain.
+For example, if options @option{-@var{a}}, @option{-@var{b}} and
+@option{-@var{c}} are mutually exclusive, their respective @code{Negative}
+properties should be @samp{Negative(@var{b})}, @samp{Negative(@var{c})}
+and @samp{Negative(@var{a})}.
+
@item Joined
@itemx Separate
The option takes a mandatory argument. @code{Joined} indicates
