* optc-gen.awk (END): Make sure no variable is defined more

[pf3gnuchains/gcc-fork.git] / gcc / doc / options.texi

diff --git a/gcc/doc/options.texi b/gcc/doc/options.texi
index ccc6c91..d5d1984 100644 (file)
--- a/gcc/doc/options.texi
+++ b/gcc/doc/options.texi
@@ -154,14 +154,20 @@ The variable specified by the @code{Var} property should be statically
 initialized to @var{value}.
 
 @item Mask(@var{name})
-The option is associated with a bit in the @code{target_flags} variable
-(@pxref{Run-time Target}) and is active when that bit is set.
-
-The options-processing script will automatically allocate a unique
-bit for the option and set the macro @code{MASK_@var{name}} to the
-appropriate bitmask.  It will also declare a @code{TARGET_@var{name}}
-macro that has the value 1 when the option is active and 0 otherwise.
-You can disable this behavior using @code{MaskExists}.
+The option is associated with a bit in the @code{target_flags}
+variable (@pxref{Run-time Target}) and is active when that bit is set.
+You may also specify @code{Var} to select a variable other than
+@code{target_flags}.
+
+The options-processing script will automatically allocate a unique bit
+for the option.  If the option is attached to @samp{target_flags},
+the script will set the macro @code{MASK_@var{name}} to the appropriate
+bitmask.  It will also declare a @code{TARGET_@var{name}} macro that has
+the value 1 when the option is active and 0 otherwise.  If you use @code{Var}
+to attach the option to a different variable, the associated macros are
+called @code{OPTION_MASK_@var{name}} and @code{OPTION_@var{name}} respectively.
+
+You can disable automatic bit alloction using @code{MaskExists}.
 
 @item InverseMask(@var{othername})
 @itemx InverseMask(@var{othername}, @var{thisname})