ada: Fix wrong visibility over discriminants

This patch fixes an issue where the compiler was incorrectly allowing
references to discriminants of the ancestor type in private type
extensions.

gcc/ada/ChangeLog:

	* sem_ch3.adb (Build_Derived_Private_Type): Fix test.
	(Build_Derived_Record_Type): Adjust error recovery paths.

1 files changed, 12 insertions, 4 deletions

diff --git a/gcc/ada/sem_ch3.adb b/gcc/ada/sem_ch3.adb
index 9a25ff7..e94b043 100644
--- a/gcc/ada/sem_ch3.adb
+++ b/gcc/ada/sem_ch3.adb
@@ -8488,11 +8488,19 @@ package body Sem_Ch3 is
 
                Analyze (Decl);
 
-               pragma Assert (Has_Discriminants (Full_Der)
-                 and then not Has_Unknown_Discriminants (Full_Der));
+               pragma
+                 Assert
+                   ((Has_Discriminants (Full_Der)
+                     and then not Has_Unknown_Discriminants (Full_Der))
+                      or else Serious_Errors_Detected > 0);
 
                Uninstall_Declarations (Par_Scope);
 
+               if Etype (Full_Der) = Any_Type then
+                  pragma Assert (Serious_Errors_Detected > 0);
+                  return;
+               end if;
+
                --  Freeze the underlying record view, to prevent generation of
                --  useless dispatching information, which is simply shared with
                --  the real derived type.
@@ -9457,8 +9465,8 @@ package body Sem_Ch3 is
       if Constraint_Present then
          if not Has_Discriminants (Parent_Base)
            or else
-             (Has_Unknown_Discriminants (Parent_Base)
-               and then Is_Private_Type (Parent_Base))
+             (Has_Unknown_Discriminants (Parent_Type)
+               and then Is_Private_Type (Parent_Type))
          then
             Error_Msg_N
               ("invalid constraint: type has no discriminant",