[COMMITTED] ada: Preliminary cleanup in aliasing support code

[COMMITTED] ada: Preliminary cleanup in aliasing support code

[Marc Poulhiès]

From: Eric Botcazou <ebotcazou@adacore.com>

This declares an explicit temporary for the fields of the fat pointer type
in gnat_to_gnu_entity and removes the GNU_ prefix of the parameters of the
relate_alias_sets routine for the sake of brevity.  No functional changes.

gcc/ada/

	* gcc-interface/decl.cc (gnat_to_gnu_entity) <E_Array_Type>: Use a
	separate FLD local variable to hold the first field of the fat
	pointer type being built.
	* gcc-interface/gigi.h (relate_alias_sets): Remove GNU_ prefix on
	the first two parameters.
	* gcc-interface/utils.cc (relate_alias_sets): Likewise and adjust.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/gcc-interface/decl.cc  | 27 +++++++++----------
 gcc/ada/gcc-interface/gigi.h   |  4 +--
 gcc/ada/gcc-interface/utils.cc | 48 ++++++++++++++++------------------
 3 files changed, 38 insertions(+), 41 deletions(-)

diff --git a/gcc/ada/gcc-interface/decl.cc b/gcc/ada/gcc-interface/decl.cc
index 89a374fab1a..221baebb554 100644
--- a/gcc/ada/gcc-interface/decl.cc
+++ b/gcc/ada/gcc-interface/decl.cc
@@ -2111,7 +2111,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
 	tree *gnu_index_types = XALLOCAVEC (tree, ndim);
 	tree *gnu_temp_fields = XALLOCAVEC (tree, ndim);
 	tree gnu_max_size = size_one_node;
-	tree comp_type, tem, obj;
+	tree comp_type, fld, tem, obj;
 	Entity_Id gnat_index;
 	alias_set_type ptr_set = -1;
 	int index;
@@ -2184,11 +2184,11 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
 	   if the FIELD_DECLs are distinct as objects.  */
 	if (COMPLETE_TYPE_P (gnu_fat_type))
 	  {
-	    tem = TYPE_FIELDS (gnu_fat_type);
-	    if (TYPE_ALIAS_SET_KNOWN_P (TREE_TYPE (tem)))
-	      ptr_set = TYPE_ALIAS_SET (TREE_TYPE (tem));
-	    TREE_TYPE (tem) = ptr_type_node;
-	    TREE_TYPE (DECL_CHAIN (tem)) = gnu_ptr_template;
+	    fld = TYPE_FIELDS (gnu_fat_type);
+	    if (TYPE_ALIAS_SET_KNOWN_P (TREE_TYPE (fld)))
+	      ptr_set = TYPE_ALIAS_SET (TREE_TYPE (fld));
+	    TREE_TYPE (fld) = ptr_type_node;
+	    TREE_TYPE (DECL_CHAIN (fld)) = gnu_ptr_template;
 	    TYPE_DECL_SUPPRESS_DEBUG (TYPE_STUB_DECL (gnu_fat_type)) = 0;
 	    for (tree t = gnu_fat_type; t; t = TYPE_NEXT_VARIANT (t))
 	      SET_TYPE_UNCONSTRAINED_ARRAY (t, gnu_type);
@@ -2197,15 +2197,15 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
 	  {
 	    /* We make the fields addressable for the sake of compatibility
 	       with languages for which the regular fields are addressable.  */
-	    tem
+	    fld
 	      = create_field_decl (get_identifier ("P_ARRAY"),
 				   ptr_type_node, gnu_fat_type,
 				   NULL_TREE, NULL_TREE, 0, 1);
-	    DECL_CHAIN (tem)
+	    DECL_CHAIN (fld)
 	      = create_field_decl (get_identifier ("P_BOUNDS"),
 				   gnu_ptr_template, gnu_fat_type,
 				   NULL_TREE, NULL_TREE, 0, 1);
-	    finish_fat_pointer_type (gnu_fat_type, tem);
+	    finish_fat_pointer_type (gnu_fat_type, fld);
 	    SET_TYPE_UNCONSTRAINED_ARRAY (gnu_fat_type, gnu_type);
 	  }
 
@@ -2230,7 +2230,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
 	   fields once we build them.  */
 	tem = build3 (COMPONENT_REF, gnu_ptr_template,
 		      build0 (PLACEHOLDER_EXPR, gnu_fat_type),
-		      DECL_CHAIN (TYPE_FIELDS (gnu_fat_type)), NULL_TREE);
+		      DECL_CHAIN (fld), NULL_TREE);
 	gnu_template_reference
 	  = build_unary_op (INDIRECT_REF, gnu_template_type, tem);
 	TREE_READONLY (gnu_template_reference) = 1;
@@ -2413,12 +2413,11 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
 	   type since the implementation type may vary between constrained
 	   subtypes and unconstrained base type.  */
 	if (Present (PAT))
-	  TREE_TYPE (TYPE_FIELDS (gnu_fat_type))
-	    = build_pointer_type_for_mode (tem, ptr_mode, true);
+	  TREE_TYPE (fld) = build_pointer_type_for_mode (tem, ptr_mode, true);
 	else
-	  TREE_TYPE (TYPE_FIELDS (gnu_fat_type)) = build_pointer_type (tem);
+	  TREE_TYPE (fld) = build_pointer_type (tem);
 	if (ptr_set != -1)
-	  TYPE_ALIAS_SET (TREE_TYPE (TYPE_FIELDS (gnu_fat_type))) = ptr_set;
+	  TYPE_ALIAS_SET (TREE_TYPE (fld)) = ptr_set;
 
 	/* If the maximum size doesn't overflow, use it.  */
 	if (gnu_max_size
diff --git a/gcc/ada/gcc-interface/gigi.h b/gcc/ada/gcc-interface/gigi.h
index 2a7320f0a4b..c1bc237e68e 100644
--- a/gcc/ada/gcc-interface/gigi.h
+++ b/gcc/ada/gcc-interface/gigi.h
@@ -158,14 +158,14 @@ enum alias_set_op
   ALIAS_SET_SUPERSET
 };
 
-/* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
+/* Relate the alias sets of NEW_TYPE and OLD_TYPE according to OP.
    If this is a multi-dimensional array type, do this recursively.
 
    OP may be
    - ALIAS_SET_COPY:     the new set is made a copy of the old one.
    - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
    - ALIAS_SET_SUBSET:   the new set is made a subset of the old one.  */
-extern void relate_alias_sets (tree gnu_new_type, tree gnu_old_type,
+extern void relate_alias_sets (tree new_type, tree old_type,
 			       enum alias_set_op op);
 
 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
diff --git a/gcc/ada/gcc-interface/utils.cc b/gcc/ada/gcc-interface/utils.cc
index 17f6afd687d..bc063c20387 100644
--- a/gcc/ada/gcc-interface/utils.cc
+++ b/gcc/ada/gcc-interface/utils.cc
@@ -1823,7 +1823,7 @@ set_reverse_storage_order_on_pad_type (tree type)
   return canonicalize_pad_type (type);
 }
 
-/* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
+/* Relate the alias sets of NEW_TYPE and OLD_TYPE according to OP.
    If this is a multi-dimensional array type, do this recursively.
 
    OP may be
@@ -1832,30 +1832,28 @@ set_reverse_storage_order_on_pad_type (tree type)
    - ALIAS_SET_SUBSET:   the new set is made a subset of the old one.  */
 
 void
-relate_alias_sets (tree gnu_new_type, tree gnu_old_type, enum alias_set_op op)
+relate_alias_sets (tree new_type, tree old_type, enum alias_set_op op)
 {
   /* Remove any padding from GNU_OLD_TYPE.  It doesn't matter in the case
      of a one-dimensional array, since the padding has the same alias set
      as the field type, but if it's a multi-dimensional array, we need to
      see the inner types.  */
-  while (TREE_CODE (gnu_old_type) == RECORD_TYPE
-	 && (TYPE_JUSTIFIED_MODULAR_P (gnu_old_type)
-	     || TYPE_PADDING_P (gnu_old_type)))
-    gnu_old_type = TREE_TYPE (TYPE_FIELDS (gnu_old_type));
+  while (TREE_CODE (old_type) == RECORD_TYPE
+	 && (TYPE_JUSTIFIED_MODULAR_P (old_type)
+	     || TYPE_PADDING_P (old_type)))
+    old_type = TREE_TYPE (TYPE_FIELDS (old_type));
 
   /* Unconstrained array types are deemed incomplete and would thus be given
      alias set 0.  Retrieve the underlying array type.  */
-  if (TREE_CODE (gnu_old_type) == UNCONSTRAINED_ARRAY_TYPE)
-    gnu_old_type
-      = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_old_type))));
-  if (TREE_CODE (gnu_new_type) == UNCONSTRAINED_ARRAY_TYPE)
-    gnu_new_type
-      = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_new_type))));
-
-  if (TREE_CODE (gnu_new_type) == ARRAY_TYPE
-      && TREE_CODE (TREE_TYPE (gnu_new_type)) == ARRAY_TYPE
-      && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_new_type)))
-    relate_alias_sets (TREE_TYPE (gnu_new_type), TREE_TYPE (gnu_old_type), op);
+  if (TREE_CODE (old_type) == UNCONSTRAINED_ARRAY_TYPE)
+    old_type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (old_type))));
+  if (TREE_CODE (new_type) == UNCONSTRAINED_ARRAY_TYPE)
+    new_type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (new_type))));
+
+  if (TREE_CODE (new_type) == ARRAY_TYPE
+      && TREE_CODE (TREE_TYPE (new_type)) == ARRAY_TYPE
+      && TYPE_MULTI_ARRAY_P (TREE_TYPE (new_type)))
+    relate_alias_sets (TREE_TYPE (new_type), TREE_TYPE (old_type), op);
 
   switch (op)
     {
@@ -1864,19 +1862,19 @@ relate_alias_sets (tree gnu_new_type, tree gnu_old_type, enum alias_set_op op)
 	 aliasing settings because this can break the aliasing relationship
 	 between the array type and its element type.  */
       if (flag_checking || flag_strict_aliasing)
-	gcc_assert (!(TREE_CODE (gnu_new_type) == ARRAY_TYPE
-		      && TREE_CODE (gnu_old_type) == ARRAY_TYPE
-		      && TYPE_NONALIASED_COMPONENT (gnu_new_type)
-			 != TYPE_NONALIASED_COMPONENT (gnu_old_type)));
+	gcc_assert (!(TREE_CODE (new_type) == ARRAY_TYPE
+		      && TREE_CODE (old_type) == ARRAY_TYPE
+		      && TYPE_NONALIASED_COMPONENT (new_type)
+			 != TYPE_NONALIASED_COMPONENT (old_type)));
 
-      TYPE_ALIAS_SET (gnu_new_type) = get_alias_set (gnu_old_type);
+      TYPE_ALIAS_SET (new_type) = get_alias_set (old_type);
       break;
 
     case ALIAS_SET_SUBSET:
     case ALIAS_SET_SUPERSET:
       {
-	alias_set_type old_set = get_alias_set (gnu_old_type);
-	alias_set_type new_set = get_alias_set (gnu_new_type);
+	alias_set_type old_set = get_alias_set (old_type);
+	alias_set_type new_set = get_alias_set (new_type);
 
 	/* Do nothing if the alias sets conflict.  This ensures that we
 	   never call record_alias_subset several times for the same pair
@@ -1895,7 +1893,7 @@ relate_alias_sets (tree gnu_new_type, tree gnu_old_type, enum alias_set_op op)
       gcc_unreachable ();
     }
 
-  record_component_aliases (gnu_new_type);
+  record_component_aliases (new_type);
 }
 
 /* Record TYPE as a builtin type for Ada.  NAME is the name of the type.
-- 
2.43.0