re PR c/21160 (documentation for -Wuninitialized out of date)

	PR c/21160
	* doc/invoke.texi (-Wuninitialized): Update documentation.

From-SVN: r99478

gcc/ChangeLog

+2005-05-09  Joseph S. Myers  <joseph@codesourcery.com>
+
+	PR c/21160
+	* doc/invoke.texi (-Wuninitialized): Update documentation.
+
 2005-05-09  Richard Earnshaw  <richard.earnshaw@arm.com>
 
 	* arm.c (const_ok_for_arm): Use a faster algorithm.

gcc/doc/invoke.texi

@@ -2565,11 +2565,13 @@ get these warnings.
 If you want to warn about code which uses the uninitialized value of the
 variable in its own initializer, use the @option{-Winit-self} option.
 
-These warnings occur only for variables that are candidates for
-register allocation.  Therefore, they do not occur for a variable that
-is declared @code{volatile}, or whose address is taken, or whose size
-is other than 1, 2, 4 or 8 bytes.  Also, they do not occur for
-structures, unions or arrays, even when they are in registers.
+These warnings occur for individual uninitialized or clobbered
+elements of structure, union or array variables as well as for
+variables which are uninitialized or clobbered as a whole.  They do
+not occur for variables or elements declared @code{volatile}.  Because
+these warnings depend on optimization, the exact variables or elements
+for which there are warnings will depend on the precise optimization
+options and version of GCC used.
 
 Note that there may be no warning about a variable that is used only
 to compute a value that itself is never used, because such