Minor tweak to elaborate_expression_1

gcc/ada/ChangeLog:
	* gcc-interface/decl.c (elaborate_expression_1): When GNAT encodings
	are not used, do not create a variable for debug info purposes if
	the expression is itself a user-declared variable.

diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c
index 270710b11d574aa46ef0e0e823f20c0bb798d542..cad06a4dd0665e8c9e44aadba3d2877ad0fd2544 100644 (file)
--- a/gcc/ada/gcc-interface/decl.c
+++ b/gcc/ada/gcc-interface/decl.c
@@ -6823,6 +6823,18 @@ elaborate_expression_1 (tree gnu_expr, Entity_Id gnat_entity, const char *s,
                         && Nkind (Associated_Node_For_Itype (gnat_entity))
                            == N_Loop_Parameter_Specification));
 
+  /* If the GNAT encodings are not used, we don't need a variable for debug
+     info purposes if the expression is a constant or another variable, but
+     we need to be careful because we do not generate debug info for external
+     variables so DECL_IGNORED_P is not stable across units.  */
+  if (need_debug
+      && gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL
+      && (TREE_CONSTANT (gnu_expr)
+         || (!expr_public_p
+             && DECL_P (gnu_expr)
+             && !DECL_IGNORED_P (gnu_expr))))
+    need_debug = false;
+
   /* Now create it, possibly only for debugging purposes.  */
   if (use_variable || need_debug)
     {
@@ -6843,10 +6855,7 @@ elaborate_expression_1 (tree gnu_expr, Entity_Id gnat_entity, const char *s,
         variable only if the variable is used by the generated code.
         Returning the variable ensures the caller will use it in generated
         code.  Note that there is no need for a location if the debug info
-        contains an integer constant.
-        TODO: when the encoding-based debug scheme is dropped, move this
-        condition to the top-level IF block: we will not need to create a
-        variable anymore in such cases, then.  */
+        contains an integer constant.  */
       if (use_variable || (need_debug && !TREE_CONSTANT (gnu_expr)))
        return gnu_decl;
     }