Multipatch:
 * TR 29113: RANK() intrinsic
 * Patch from http://gcc.gnu.org/ml/fortran/2011-05/msg00123.html
 * minor libgfortran cleanup
 AND:
 * First part of a registering patch.
   TODO:
   - Make coarrays pointer - and assign malloced memory
   - Add token variable
   - LIB: Free memory in finalize

diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 3b4967d..1f3be2d 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -472,6 +472,7 @@ enum gfc_isym_id
   GFC_ISYM_RANDOM_NUMBER,
   GFC_ISYM_RANDOM_SEED,
   GFC_ISYM_RANGE,
+  GFC_ISYM_RANK,
   GFC_ISYM_REAL,
   GFC_ISYM_RENAME,
   GFC_ISYM_REPEAT,
diff --git a/gcc/fortran/intrinsic.c b/gcc/fortran/intrinsic.c
index c0eeb6d..dc9e756 100644
--- a/gcc/fortran/intrinsic.c
+++ b/gcc/fortran/intrinsic.c
@@ -2433,6 +2433,11 @@ add_functions (void)
 
   make_generic ("range", GFC_ISYM_RANGE, GFC_STD_F95);
 
+  add_sym_1 ("rank", GFC_ISYM_RANK, CLASS_INQUIRY, ACTUAL_NO, BT_INTEGER, di,
+	     GFC_STD_F2008_TR, NULL, gfc_simplify_rank, NULL,
+	     a, BT_REAL, dr, REQUIRED);
+  make_generic ("rank", GFC_ISYM_RANK, GFC_STD_F2008_TR);
+
   add_sym_2 ("real", GFC_ISYM_REAL, CLASS_ELEMENTAL, ACTUAL_NO, BT_REAL, dr, GFC_STD_F77,
 	     gfc_check_real, gfc_simplify_real, gfc_resolve_real,
 	     a, BT_UNKNOWN, dr, REQUIRED, kind, BT_INTEGER, di, OPTIONAL);
diff --git a/gcc/fortran/intrinsic.h b/gcc/fortran/intrinsic.h
index 033bae0..6d1c42b 100644
--- a/gcc/fortran/intrinsic.h
+++ b/gcc/fortran/intrinsic.h
@@ -345,6 +345,7 @@ gfc_expr *gfc_simplify_precision (gfc_expr *);
 gfc_expr *gfc_simplify_product (gfc_expr *, gfc_expr *, gfc_expr *);
 gfc_expr *gfc_simplify_radix (gfc_expr *);
 gfc_expr *gfc_simplify_range (gfc_expr *);
+gfc_expr *gfc_simplify_rank (gfc_expr *);
 gfc_expr *gfc_simplify_real (gfc_expr *, gfc_expr *);
 gfc_expr *gfc_simplify_realpart (gfc_expr *);
 gfc_expr *gfc_simplify_repeat (gfc_expr *, gfc_expr *);
diff --git a/gcc/fortran/intrinsic.texi b/gcc/fortran/intrinsic.texi
index 804b31f..8b41e62 100644
--- a/gcc/fortran/intrinsic.texi
+++ b/gcc/fortran/intrinsic.texi
@@ -236,6 +236,7 @@ Some basic guidelines for editing this document:
 * @code{RANDOM_SEED}:   RANDOM_SEED, Initialize a pseudo-random number sequence
 * @code{RAND}:          RAND,      Real pseudo-random number
 * @code{RANGE}:         RANGE,     Decimal exponent range
+* @code{RANK} :         RANK,      Rank of a data object
 * @code{RAN}:           RAN,       Real pseudo-random number
 * @code{REAL}:          REAL,      Convert to real type 
 * @code{RENAME}:        RENAME,    Rename a file
@@ -10115,6 +10116,47 @@ See @code{PRECISION} for an example.
 
 
 
+@node RANK
+@section @code{RANK} --- Rank of a data object
+@fnindex RANK
+@cindex rank
+
+@table @asis
+@item @emph{Description}:
+@code{RANK(A)} returns the rank of a scalar or array data object.
+
+@item @emph{Standard}:
+Technical Report (TR) 29113
+
+@item @emph{Class}:
+Inquiry function
+
+@item @emph{Syntax}:
+@code{RESULT = RANGE(A)}
+
+@item @emph{Arguments}:
+@multitable @columnfractions .15 .70
+@item @var{A} @tab can be of any type
+@end multitable
+
+@item @emph{Return value}:
+The return value is of type @code{INTEGER} and of the default integer
+kind. For arrays, their rank is returned; for scalars zero is returned.
+
+@item @emph{Example}:
+@smallexample
+program test_real
+  integer :: a
+  real, allocatable :: b(:,::)
+
+  print *, rank(a), rank(b) ! Prints:  0  3
+end program test_real
+@end smallexample
+
+@end table
+
+
+
 @node REAL
 @section @code{REAL} --- Convert to real type 
 @fnindex REAL
diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index 4c91563..79b383a 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -4822,6 +4822,13 @@ gfc_simplify_range (gfc_expr *e)
 
 
 gfc_expr *
+gfc_simplify_rank (gfc_expr *e)
+{
+  return gfc_get_int_expr (gfc_default_integer_kind, &e->where, e->rank);
+}
+
+
+gfc_expr *
 gfc_simplify_real (gfc_expr *e, gfc_expr *k)
 {
   gfc_expr *result = NULL;
diff --git a/gcc/fortran/trans-array.c b/gcc/fortran/trans-array.c
index 1a4ab39..78d65a6 100644
--- a/gcc/fortran/trans-array.c
+++ b/gcc/fortran/trans-array.c
@@ -2621,7 +2621,12 @@ gfc_conv_array_ref (gfc_se * se, gfc_array_ref * ar, gfc_symbol * sym,
   gfc_se tmpse;
 
   if (ar->dimen == 0)
-    return;
+    {
+      gcc_assert (ar->codimen);
+      /* Use the actual tree type and not the wrapped coarray. */
+      se->expr = fold_convert (TREE_TYPE (TREE_TYPE (se->expr)), se->expr);
+      return;
+    }
 
   /* Handle scalarized references separately.  */
   if (ar->type != AR_ELEMENT)
diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index d771484..c5ab609 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -78,6 +78,11 @@ static gfc_namespace *module_namespace;
 static gfc_symbol* current_procedure_symbol = NULL;
 
 
+/* For -fcoarray=lib's autoconstructor.  */
+static bool has_coarray_vars;
+static stmtblock_t caf_init_block;
+
+
 /* List of static constructor functions.  */
 
 tree gfc_static_ctors;
@@ -114,6 +119,7 @@ tree gfor_fndecl_associated;
 /* Coarray run-time library function decls.  */
 tree gfor_fndecl_caf_init;
 tree gfor_fndecl_caf_finalize;
+tree gfor_fndecl_caf_register;
 tree gfor_fndecl_caf_critical;
 tree gfor_fndecl_caf_end_critical;
 tree gfor_fndecl_caf_sync_all;
@@ -1403,7 +1409,8 @@ gfc_get_symbol_decl (gfc_symbol * sym)
       && !(sym->attr.use_assoc && !intrinsic_array_parameter)
       && (sym->attr.save || sym->ns->proc_name->attr.is_main_program
 	  || gfc_option.flag_max_stack_var_size == 0
-	  || sym->attr.data || sym->ns->proc_name->attr.flavor == FL_MODULE))
+	  || sym->attr.data || sym->ns->proc_name->attr.flavor == FL_MODULE)
+      && (gfc_option.coarray != GFC_FCOARRAY_LIB|| !sym->attr.codimension))
     {
       /* Add static initializer. For procedures, it is only needed if
 	 SAVE is specified otherwise they need to be reinitialized
@@ -3025,6 +3032,11 @@ gfc_build_builtin_function_decls (void)
       gfor_fndecl_caf_finalize = gfc_build_library_function_decl (
 	get_identifier (PREFIX("caf_finalize")), void_type_node, 0);
 
+      gfor_fndecl_caf_register = gfc_build_library_function_decl_with_spec (
+	get_identifier (PREFIX("caf_register")), "...WWW", pvoid_type_node, 6,
+        size_type_node, integer_type_node, pvoid_type_node, pint_type,
+        build_pointer_type (pchar_type_node), integer_type_node);
+
       gfor_fndecl_caf_critical = gfc_build_library_function_decl (
 	get_identifier (PREFIX("caf_critical")), void_type_node, 0);
 
@@ -4066,6 +4078,9 @@ gfc_emit_parameter_debug_info (gfc_symbol *sym)
 				   sym->attr.dimension, false))
     return;
 
+  if (gfc_option.coarray == GFC_FCOARRAY_LIB && sym->attr.codimension)
+    return;
+
   /* Create the decl for the variable or constant.  */
   decl = build_decl (input_location,
 		     sym->attr.flavor == FL_PARAMETER ? CONST_DECL : VAR_DECL,
@@ -4200,6 +4215,9 @@ generate_local_decl (gfc_symbol * sym)
 {
   if (sym->attr.flavor == FL_VARIABLE)
     {
+      if (sym->attr.codimension && !sym->attr.dummy && !sym->attr.allocatable)
+	has_coarray_vars = true;
+
       if (!sym->attr.dummy && !sym->ns->proc_name->attr.entry_master)
 	generate_dependency_declarations (sym);
 
@@ -4721,6 +4739,14 @@ create_main_function (tree fndecl)
       gfc_add_expr_to_block (&body, tmp);
     }
 
+  if (gfc_option.coarray == GFC_FCOARRAY_LIB)
+    {
+      tmp = build_call_expr_loc (input_location, gfor_fndecl_caf_sync_all,
+                                 2, null_pointer_node,
+				 build_int_cst (integer_type_node, 0));
+      gfc_add_expr_to_block (&body, tmp);
+    }
+
   /* Call MAIN__().  */
   tmp = build_call_expr_loc (input_location,
 			 fndecl, 0);
@@ -4826,6 +4852,121 @@ gfc_generate_return (void)
 }
 
 
+static void
+generate_coarray_sym_init (gfc_symbol *sym)
+{
+  tree tmp, size, decl;
+
+  if (sym->attr.dummy || sym->attr.allocatable || !sym->attr.codimension)
+    return;
+
+  if (!sym->attr.referenced)
+    return;
+
+  decl = sym->backend_decl;
+  gcc_assert (GFC_ARRAY_TYPE_P (TREE_TYPE (decl)));
+
+  size = TYPE_SIZE_UNIT (gfc_get_element_type (TREE_TYPE (decl)));
+
+  if (GFC_TYPE_ARRAY_RANK (TREE_TYPE (decl)))
+    {
+      tmp = GFC_TYPE_ARRAY_SIZE (TREE_TYPE (decl));
+      size = fold_build2_loc (input_location, MULT_EXPR, size_type_node,
+			      fold_convert (size_type_node, tmp),
+			      fold_convert (size_type_node, size));
+    }
+
+  tmp = build_call_expr_loc (input_location, gfor_fndecl_caf_register, 6,
+			     size,
+			     build_int_cst (integer_type_node, 0), /* type.  */
+			     null_pointer_node, /* token.  */
+			     null_pointer_node, /* stat.  */
+			     null_pointer_node, /* errgmsg.  */
+			     build_int_cst (integer_type_node, 0)); /* errmsg_len.  */
+  gfc_add_expr_to_block (&caf_init_block, tmp);
+
+  /* "Static" initializer.  */
+  if (!sym->value)
+    return;
+
+  tmp = gfc_trans_assignment (gfc_lval_expr_from_sym (sym), sym->value, true, false);
+  gfc_add_expr_to_block (&caf_init_block, tmp);
+}
+
+
+/* Generate constructor function to initialize static, nonallocatable
+   coarrays.  */
+
+static void
+generate_coarray_init (gfc_namespace * ns __attribute((unused)))
+{
+  tree old_context, fndecl, tmp, decl;
+
+  old_context = current_function_decl;
+
+  if (old_context)
+    {
+      push_function_context ();
+      saved_parent_function_decls = saved_function_decls;
+      saved_function_decls = NULL_TREE;
+    }
+
+  tmp = build_function_type_list (void_type_node, NULL_TREE);
+  fndecl = build_decl (input_location, FUNCTION_DECL,
+		       create_tmp_var_name ("_caf_init"), tmp);
+
+  DECL_STATIC_CONSTRUCTOR (fndecl) = 1;
+  SET_DECL_INIT_PRIORITY (fndecl, DEFAULT_INIT_PRIORITY);
+  TREE_USED (fndecl) = 1;
+
+  decl = build_decl (input_location, RESULT_DECL, NULL_TREE, void_type_node);
+  DECL_ARTIFICIAL (decl) = 1;
+  DECL_IGNORED_P (decl) = 1;
+  DECL_CONTEXT (decl) = fndecl;
+  DECL_RESULT (fndecl) = decl;
+
+  pushdecl (fndecl);
+  current_function_decl = fndecl;
+  announce_function (fndecl);
+
+  rest_of_decl_compilation (fndecl, 1, 0);
+  make_decl_rtl (fndecl);
+  init_function_start (fndecl);
+
+  pushlevel (0);
+  gfc_init_block (&caf_init_block);
+
+  gfc_traverse_ns (ns, generate_coarray_sym_init);
+
+  DECL_SAVED_TREE (fndecl) = gfc_finish_block (&caf_init_block);
+  decl = getdecls ();
+
+  poplevel (1, 0, 1);
+  BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl;
+
+  DECL_SAVED_TREE (fndecl)
+    = build3_v (BIND_EXPR, decl, DECL_SAVED_TREE (fndecl),
+                DECL_INITIAL (fndecl));
+  dump_function (TDI_original, fndecl);
+
+  cfun->function_end_locus = input_location;
+
+  set_cfun (NULL);
+
+  if (old_context)
+    {
+      pop_function_context ();
+      saved_function_decls = saved_parent_function_decls;
+    }
+  current_function_decl = old_context;
+
+  if (decl_function_context (fndecl))
+    (void) cgraph_create_node (fndecl);
+  else
+    cgraph_finalize_function (fndecl, true);
+}
+
+
 /* Generate code for a function.  */
 
 void
@@ -4897,8 +5038,12 @@ gfc_generate_function_code (gfc_namespace * ns)
   nonlocal_dummy_decls = NULL;
   nonlocal_dummy_decl_pset = NULL;
 
+  has_coarray_vars = false;
   generate_local_vars (ns);
 
+  if (gfc_option.coarray == GFC_FCOARRAY_LIB && has_coarray_vars)
+    generate_coarray_init (ns);
+
   /* Keep the parent fake result declaration in module functions
      or external procedures.  */
   if ((ns->parent && ns->parent->proc_name->attr.flavor == FL_MODULE)
diff --git a/gcc/fortran/trans-types.c b/gcc/fortran/trans-types.c
index 24fdcf3..1165926 100644
--- a/gcc/fortran/trans-types.c
+++ b/gcc/fortran/trans-types.c
@@ -1100,8 +1100,16 @@ gfc_get_element_type (tree type)
     {
       if (TREE_CODE (type) == POINTER_TYPE)
         type = TREE_TYPE (type);
-      gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
-      element = TREE_TYPE (type);
+      if (GFC_TYPE_ARRAY_RANK (type) == 0)
+	{
+	  gcc_assert (GFC_TYPE_ARRAY_CORANK (type) > 0);
+	  element = type;
+	}
+      else
+	{
+	  gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
+	  element = TREE_TYPE (type);
+	}
     }
   else
     {
@@ -1412,7 +1420,13 @@ gfc_get_nodesc_array_type (tree etype, gfc_array_spec * as, gfc_packed packed,
   /* We don't use build_array_type because this does not include include
      lang-specific information (i.e. the bounds of the array) when checking
      for duplicates.  */
-  type = make_node (ARRAY_TYPE);
+  if (as->rank)
+    type = make_node (ARRAY_TYPE);
+  else
+    {
+      type = build_variant_type_copy (etype);
+      TREE_TYPE (type) = etype;
+    }
 
   GFC_ARRAY_TYPE_P (type) = 1;
   TYPE_LANG_SPECIFIC (type)
@@ -1526,6 +1540,23 @@ gfc_get_nodesc_array_type (tree etype, gfc_array_spec * as, gfc_packed packed,
       build_qualified_type (GFC_TYPE_ARRAY_DATAPTR_TYPE (type),
 			    TYPE_QUAL_RESTRICT);
 
+  if (as->rank == 0)
+    {
+      if (packed != PACKED_STATIC)
+	type = build_pointer_type (type);
+
+      if (restricted)
+        type = build_qualified_type (type, TYPE_QUAL_RESTRICT);	
+
+      if (packed != PACKED_STATIC)
+	{
+	  GFC_ARRAY_TYPE_P (type) = 1;
+	  TYPE_LANG_SPECIFIC (type) = TYPE_LANG_SPECIFIC (TREE_TYPE (type)); 
+	}
+
+      return type;
+    }
+
   if (known_stride)
     {
       mpz_sub_ui (stride, stride, 1);
diff --git a/gcc/fortran/trans.c b/gcc/fortran/trans.c
index 1d25cb0..fcbb850 100644
--- a/gcc/fortran/trans.c
+++ b/gcc/fortran/trans.c
@@ -316,6 +316,13 @@ gfc_build_array_ref (tree base, tree offset, tree decl)
   tree type = TREE_TYPE (base);
   tree tmp;
 
+  if (GFC_ARRAY_TYPE_P (type) && GFC_TYPE_ARRAY_RANK (type) == 0)
+    {
+      gcc_assert (GFC_TYPE_ARRAY_CORANK (type) > 0);
+
+      return fold_convert (TREE_TYPE (type), base);
+    }
+
   gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
   type = TREE_TYPE (type);
 
diff --git a/gcc/fortran/trans.h b/gcc/fortran/trans.h
index 2b06d80..e9b07b6 100644
--- a/gcc/fortran/trans.h
+++ b/gcc/fortran/trans.h
@@ -617,6 +617,7 @@ extern GTY(()) tree gfor_fndecl_associated;
 /* Coarray run-time library function decls.  */
 extern GTY(()) tree gfor_fndecl_caf_init;
 extern GTY(()) tree gfor_fndecl_caf_finalize;
+extern GTY(()) tree gfor_fndecl_caf_register;
 extern GTY(()) tree gfor_fndecl_caf_critical;
 extern GTY(()) tree gfor_fndecl_caf_end_critical;
 extern GTY(()) tree gfor_fndecl_caf_sync_all;
diff --git a/libgfortran/caf/mpi.c b/libgfortran/caf/mpi.c
index 9b7bb33..8b1f424 100644
--- a/libgfortran/caf/mpi.c
+++ b/libgfortran/caf/mpi.c
@@ -80,7 +80,6 @@ _gfortran_caf_register (ptrdiff_t size,
                         caf_register_t type __attribute__ ((unused)),
                         void **token)
 {
-  *token = NULL;
   return malloc (size);
 }
 
diff --git a/libgfortran/caf/single.c b/libgfortran/caf/single.c
index c5c66b4..c9cbc7f 100644
--- a/libgfortran/caf/single.c
+++ b/libgfortran/caf/single.c
@@ -55,9 +55,8 @@ _gfortran_caf_finalize (void)
 void *
 _gfortran_caf_register (ptrdiff_t size,
 			caf_register_t type __attribute__ ((unused)),
-			void **token)
+			void **token __attribute__ ((unused)))
 {
-  *token = NULL;
   return malloc (size);
 }
 
diff --git a/libgfortran/runtime/stop.c b/libgfortran/runtime/stop.c
index 4c3a0f9..912dd54 100644
--- a/libgfortran/runtime/stop.c
+++ b/libgfortran/runtime/stop.c
@@ -67,8 +67,7 @@ stop_string (const char *string, GFC_INTEGER_4 len)
   if (string)
     {
       estr_write ("STOP ");
-      ssize_t w = write (STDERR_FILENO, string, len);
-      (void) sizeof (w); /* Avoid compiler warning about not using w.  */
+      (void) write (STDERR_FILENO, string, len);
       estr_write ("\n");
     }
   exit (0);
@@ -88,8 +87,7 @@ void
 error_stop_string (const char *string, GFC_INTEGER_4 len)
 {
   estr_write ("ERROR STOP ");
-  ssize_t w = write (STDERR_FILENO, string, len);
-  (void) sizeof (w); /* Avoid compiler warning about not using w.  */
+  (void) write (STDERR_FILENO, string, len);
   estr_write ("\n");
 
   exit (1);