re PR fortran/34928 (Extension: volatile common blocks)

        PR fortran/34928
        * fortran.texi: Document Volatile COMMON as not supported.

From-SVN: r208852

gcc/fortran/ChangeLog

+2014-03-26 Dominique d'Humieres <dominiq@lps.ens.fr>
+
+	PR fortran/34928
+	* fortran.texi: Document Volatile COMMON as not supported.
+
 2014-03-22  Jakub Jelinek  <jakub@redhat.com>
 
 	PR debug/60603

gcc/fortran/gfortran.texi

@@ -2003,6 +2003,7 @@ code that uses them running with the GNU Fortran compiler.
 @c * CARRIAGECONTROL, DEFAULTFILE, DISPOSE and RECORDTYPE I/O specifiers::
 @c * Omitted arguments in procedure call::
 * Alternate complex function syntax::
+* Volatile COMMON blocks::
 @end menu
 
 
@@ -2197,6 +2198,18 @@ extensions.  @command{gfortran} accepts the latter form, which is more
 common, but not the former.
 
 
+@node Volatile COMMON blocks
+@subsection Volatile @code{COMMON} blocks
+@cindex @code{VOLATILE}
+@cindex @code{COMMON}
+
+Some Fortran compilers, including @command{g77}, let the user declare
+@code{COMMON} with the @code{VOLATILE} attribute. This is
+invalid standard Fortran syntax and is not supported by
+@command{gfortran}.  Note that @command{gfortran} accepts
+@code{VOLATILE} variables in @code{COMMON} blocks since revision 4.3.
+
+
 
 @c ---------------------------------------------------------------------
 @c Mixed-Language Programming