diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 0aa3fab80864d605d5f45de0645b81648b7d1ccb..a0c881d445d8254c2a223d6dcdcc24d9af6f700e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2011-04-14 Richard Sandiford <rdsandiford@googlemail.com> + + * doc/options.texi (Negative): Explicitly mention that the + Negative chain must be circular. + 2011-04-14 Nathan Froyd <froydnj@codesourcery.com> * function.h (block_chainon): Declare. diff --git a/gcc/doc/options.texi b/gcc/doc/options.texi index 69e73645893b62203e1fcdc53730e0c2546548a2..edab7a9da663f18763f841ce27a27d9e49b0a4fb 100644 --- a/gcc/doc/options.texi +++ b/gcc/doc/options.texi @@ -222,6 +222,13 @@ the option name with the leading ``-'' removed. This chain action will 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