[gcc r12-6472] [Ada] Relax assertion on designated types for equality operators

[gcc r12-6472] [Ada] Relax assertion on designated types for equality operators

[Pierre-Marie de Rodat]

https://gcc.gnu.org/g:7317a46128a3572f39d1d8f96155111d00d9d229

commit r12-6472-g7317a46128a3572f39d1d8f96155111d00d9d229
Author: Eric Botcazou <ebotcazou@adacore.com>
Date:   Mon Jan 3 16:15:20 2022 +0100

    [Ada] Relax assertion on designated types for equality operators
    
    gcc/ada/
    
            * gcc-interface/utils2.c (build_binary_op) <EQ_EXPR>: Relax a
            little the assertion on designated types of pointer types.

Diff:
---
 gcc/ada/gcc-interface/utils2.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/gcc/ada/gcc-interface/utils2.c b/gcc/ada/gcc-interface/utils2.c
index 06d82035c67..b651d486afb 100644
--- a/gcc/ada/gcc-interface/utils2.c
+++ b/gcc/ada/gcc-interface/utils2.c
@@ -6,7 +6,7 @@
  *                                                                          *
  *                          C Implementation File                           *
  *                                                                          *
- *          Copyright (C) 1992-2021, Free Software Foundation, Inc.         *
+ *          Copyright (C) 1992-2022, Free Software Foundation, Inc.         *
  *                                                                          *
  * GNAT is free software;  you can  redistribute it  and/or modify it under *
  * terms of the  GNU General Public License as published  by the Free Soft- *
@@ -1118,7 +1118,7 @@ build_binary_op (enum tree_code op_code, tree result_type,
 	  return result;
 	}
 
-      /* Otherwise, the base types must be the same, unless they are both fat
+      /* Otherwise, the base types must be the same, unless they are both (fat)
 	 pointer types or record types.  In the latter case, use the best type
 	 and convert both operands to that type.  */
       if (left_base_type != right_base_type)
@@ -1131,6 +1131,18 @@ build_binary_op (enum tree_code op_code, tree result_type,
 	      best_type = left_base_type;
 	    }
 
+	  else if (POINTER_TYPE_P (left_base_type)
+		   && POINTER_TYPE_P (right_base_type))
+	    {
+	      /* Anonymous access types in Ada 2005 can point to different
+		 members of a tagged type hierarchy.  */
+	      gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (left_base_type))
+			  == TYPE_MAIN_VARIANT (TREE_TYPE (right_base_type))
+			  || (TYPE_ALIGN_OK (TREE_TYPE (left_base_type))
+			      && TYPE_ALIGN_OK (TREE_TYPE (right_base_type))));
+	      best_type = left_base_type;
+	    }
+
 	  else if (TREE_CODE (left_base_type) == RECORD_TYPE
 		   && TREE_CODE (right_base_type) == RECORD_TYPE)
 	    {
@@ -1153,13 +1165,6 @@ build_binary_op (enum tree_code op_code, tree result_type,
 		gcc_unreachable ();
 	    }
 
-	  else if (POINTER_TYPE_P (left_base_type)
-		   && POINTER_TYPE_P (right_base_type))
-	    {
-	      gcc_assert (TREE_TYPE (left_base_type)
-			  == TREE_TYPE (right_base_type));
-	      best_type = left_base_type;
-	    }
 	  else
 	    gcc_unreachable ();