[gcc(refs/users/giulianob/heads/autopar_rebase2)] Emit user subtypes with -fgnat-encodings=minimal

[Giuliano Belinassi]

https://gcc.gnu.org/g:ceaca3433b9868de5448d685f775dd3ec3dd7f85

commit ceaca3433b9868de5448d685f775dd3ec3dd7f85
Author: Eric Botcazou <ebotcazou@gcc.gnu.org>
Date:   Tue Jun 23 17:37:17 2020 +0200

    Emit user subtypes with -fgnat-encodings=minimal
    
    This changes the compiler to emit debug info for user-defined subtypes
    with -fgnat-encodings=minimal, as they might be needed by the debugger.
    
    gcc/ada/ChangeLog:
            * gcc-interface/decl.c (gnat_to_gnu_entity) <E_Record_Subtype>: Set
            debug type to the base type and only if the subtype is artificial.

Diff:
---
 gcc/ada/gcc-interface/decl.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c
index 33d59d556a2..589154ba392 100644
--- a/gcc/ada/gcc-interface/decl.c
+++ b/gcc/ada/gcc-interface/decl.c
@@ -3507,18 +3507,6 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
 
 	      gnu_type = make_node (RECORD_TYPE);
 	      TYPE_NAME (gnu_type) = gnu_entity_name;
-	      if (gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL)
-		{
-		  /* Use the ultimate base record type as the debug type.
-		     Subtypes and derived types bring no useful
-		     information.  */
-		  Entity_Id gnat_debug_type = gnat_entity;
-		  while (Etype (gnat_debug_type) != gnat_debug_type)
-		    gnat_debug_type = Etype (gnat_debug_type);
-		  tree gnu_debug_type
-		    = TYPE_MAIN_VARIANT (gnat_to_gnu_type (gnat_debug_type));
-		  SET_TYPE_DEBUG_TYPE (gnu_type, gnu_debug_type);
-		}
 	      TYPE_PACKED (gnu_type) = TYPE_PACKED (gnu_base_type);
 	      TYPE_REVERSE_STORAGE_ORDER (gnu_type)
 		= Reverse_Storage_Order (gnat_entity);
@@ -3580,6 +3568,13 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
 					 true, debug_info_p,
 					 NULL, gnat_entity);
 		}
+
+	      /* Or else, if the subtype is artificial and encodings are not
+		 used, use the base record type as the debug type.  */
+	      else if (debug_info_p
+		       && artificial_p
+		       && gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL)
+		SET_TYPE_DEBUG_TYPE (gnu_type, gnu_unpad_base_type);
 	    }
 
 	  /* Otherwise, go down all the components in the new type and make