[PATCH] Document -print-multi-os-directory in invoke.texi

[Jakub Jelinek <jakub@redhat.com>]

Hi!

This switch isn't documented in invoke.texi, only in gcc --help.
Ok for trunk?

2009-10-21  Jakub Jelinek  <jakub@redhat.com>

	* doc/invoke.texi: Document -print-multi-os-directory.

--- gcc/doc/invoke.texi.jj	2009-10-15 22:07:38.000000000 +0200
+++ gcc/doc/invoke.texi	2009-10-21 10:20:10.000000000 +0200
@@ -321,7 +321,7 @@ Objective-C and Objective-C++ Dialects}.
 -femit-struct-debug-baseonly -femit-struct-debug-reduced @gol
 -femit-struct-debug-detailed@r{[}=@var{spec-list}@r{]} @gol
 -p  -pg  -print-file-name=@var{library}  -print-libgcc-file-name @gol
--print-multi-directory  -print-multi-lib @gol
+-print-multi-directory  -print-multi-lib  -print-multi-os-directory @gol
 -print-prog-name=@var{program}  -print-search-dirs  -Q @gol
 -print-sysroot -print-sysroot-headers-suffix @gol
 -save-temps -save-temps=cwd -save-temps=obj -time@r{[}=@var{file}@r{]}}
@@ -5531,6 +5531,16 @@ that enable them.  The directory name is
 @samp{-}, without spaces between multiple switches.  This is supposed to
 ease shell-processing.
 
+@item -print-multi-os-directory
+@opindex print-multi-os-directory
+Print the path to OS libraries for the selected
+multilib, relative to some @code{lib} subdirectory.  If OS libraries are
+present in the @code{lib} subdirectory and no multilibs are used, this is usually
+just @code{.}, if OS libraries are present in @code{libSUFFIX} sibling directories
+this prints e.g. @code{../lib64}, @code{../lib} or @code{../lib32}, or if
+OS libraries are present in @code{lib/SUBDIR} subdirectories it prints e.g.
+@code{amd64}, @code{sparcv9} or @code{ev6}.
+
 @item -print-prog-name=@var{program}
 @opindex print-prog-name
 Like @option{-print-file-name}, but searches for a program such as @samp{cpp}.

	Jakub