tree.c (build_array_type_1): Add SET_CANONICAL parameter and compute…

tree.c (build_array_type_1): Add SET_CANONICAL parameter and compute TYPE_CANONICAL from the element type...

	* tree.c (build_array_type_1): Add SET_CANONICAL parameter and compute
	TYPE_CANONICAL from the element type only if it is true.  Remove a few
	obsolete lines and adjust recursive call.
	(fld_process_array_type): Adjust call to build_array_type_1.
	(build_array_type): Likewise.
	(build_nonshared_array_type): Likewise.

From-SVN: r279133

gcc/ChangeLog

+2019-12-09  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* tree.c (build_array_type_1): Add SET_CANONICAL parameter and compute
+	TYPE_CANONICAL from the element type only if it is true.  Remove a few
+	obsolete lines and adjust recursive call.
+	(fld_process_array_type): Adjust call to build_array_type_1.
+	(build_array_type): Likewise.
+	(build_nonshared_array_type): Likewise.
+
 2019-12-09  Andrew Stubbs  <ams@codesourcery.com>
 
 	* config/gcn/gcn-valu.md (gather<mode>_insn_1offset<exec>): Change

gcc/testsuite/ChangeLog

+2019-12-09  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/lto23.adb: New test.
+
 2019-12-09  Joseph Myers  <joseph@codesourcery.com>
 
 	PR middle-end/91226

gcc/testsuite/gnat.dg/lto23.adb

+-- { dg-do compile }
+-- { dg-options "-flto" { target lto } }
+
+procedure Lto23 (N : Natural) is
+
+  type Root is tagged null record;
+
+  type Vec is array (Positive range <>) of Root;
+
+  type Rec is record
+    V : Vec (1 .. N);
+  end record;
+
+  type Arr is array (Positive range <>) of Rec;
+
+  A : Arr (1 .. 4);
+
+begin
+  null;
+end;

gcc/tree.c

@@ -266,7 +266,7 @@ static void print_type_hash_statistics (void);
 static void print_debug_expr_statistics (void);
 static void print_value_expr_statistics (void);
 
-static tree build_array_type_1 (tree, tree, bool, bool);
+static tree build_array_type_1 (tree, tree, bool, bool, bool);
 
 tree global_trees[TI_MAX];
 tree integer_types[itk_none];
@@ -5303,8 +5303,9 @@ fld_process_array_type (tree t, tree t2, hash_map<tree, tree> *map,
      = map->get_or_insert (t, &existed);
   if (!existed)
     {
-      array = build_array_type_1 (t2, TYPE_DOMAIN (t),
-				  TYPE_TYPELESS_STORAGE (t), false);
+      array
+	= build_array_type_1 (t2, TYPE_DOMAIN (t), TYPE_TYPELESS_STORAGE (t),
+			      false, false);
       TYPE_CANONICAL (array) = TYPE_CANONICAL (t);
       if (!fld->pset.add (array))
 	add_tree_to_fld_list (array, fld);
@@ -8155,11 +8156,12 @@ subrange_type_for_debug_p (const_tree type, tree *lowval, tree *highval)
 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
    and number of elements specified by the range of values of INDEX_TYPE.
    If TYPELESS_STORAGE is true, TYPE_TYPELESS_STORAGE flag is set on the type.
-   If SHARED is true, reuse such a type that has already been constructed.  */
+   If SHARED is true, reuse such a type that has already been constructed.
+   If SET_CANONICAL is true, compute TYPE_CANONICAL from the element type.  */
 
 static tree
 build_array_type_1 (tree elt_type, tree index_type, bool typeless_storage,
-		    bool shared)
+		    bool shared, bool set_canonical)
 {
   tree t;
 
@@ -8176,19 +8178,13 @@ build_array_type_1 (tree elt_type, tree index_type, bool typeless_storage,
   TYPE_TYPELESS_STORAGE (t) = typeless_storage;
   layout_type (t);
 
-  /* If the element type is incomplete at this point we get marked for
-     structural equality.  Do not record these types in the canonical
-     type hashtable.  */
-  if (TYPE_STRUCTURAL_EQUALITY_P (t))
-    return t;
-
   if (shared)
     {
       hashval_t hash = type_hash_canon_hash (t);
       t = type_hash_canon (hash, t);
     }
 
-  if (TYPE_CANONICAL (t) == t)
+  if (TYPE_CANONICAL (t) == t && set_canonical)
     {
       if (TYPE_STRUCTURAL_EQUALITY_P (elt_type)
 	  || (index_type && TYPE_STRUCTURAL_EQUALITY_P (index_type))
@@ -8200,7 +8196,7 @@ build_array_type_1 (tree elt_type, tree index_type, bool typeless_storage,
 	  = build_array_type_1 (TYPE_CANONICAL (elt_type),
 				index_type
 				? TYPE_CANONICAL (index_type) : NULL_TREE,
-				typeless_storage, shared);
+				typeless_storage, shared, set_canonical);
     }
 
   return t;
@@ -8211,7 +8207,8 @@ build_array_type_1 (tree elt_type, tree index_type, bool typeless_storage,
 tree
 build_array_type (tree elt_type, tree index_type, bool typeless_storage)
 {
-  return build_array_type_1 (elt_type, index_type, typeless_storage, true);
+  return
+    build_array_type_1 (elt_type, index_type, typeless_storage, true, true);
 }
 
 /* Wrapper around build_array_type_1 with SHARED set to false.  */
@@ -8219,7 +8216,7 @@ build_array_type (tree elt_type, tree index_type, bool typeless_storage)
 tree
 build_nonshared_array_type (tree elt_type, tree index_type)
 {
-  return build_array_type_1 (elt_type, index_type, false, false);
+  return build_array_type_1 (elt_type, index_type, false, false, true);
 }
 
 /* Return a representation of ELT_TYPE[NELTS], using indices of type