[Ada] Missing predicate function body for derived type in nested package

This patch fixes a bug in the construction of predicate functions.  For a
derived type, we must ensure that the parent type is already frozen so that its
predicate function has been constructed already. This is necessary if the
parent is declared in a nested package and its own freeze point has not been
reached when the derived type is frozen by a local object declaration.

2018-06-11  Ed Schonberg  <schonberg@adacore.com>

gcc/ada/

	* sem_ch13.adb (Build_Predicate_Functions): For a derived type, ensure
	that its parent is already frozen so that its predicate function, if
	any, has already been constructed.

gcc/testsuite/

	* gnat.dg/predicate1.adb: New testcase.

From-SVN: r261422

1 files changed, 15 insertions, 1 deletions

diff --git a/gcc/ada/sem_ch13.adb b/gcc/ada/sem_ch13.adb
index efa2709..ad9e9a1 100644
--- a/gcc/ada/sem_ch13.adb
+++ b/gcc/ada/sem_ch13.adb
@@ -11114,13 +11114,27 @@ package body Sem_Ch13 is
 
       --  If we have a type with predicates, build predicate function. This is
       --  not needed in the generic case, nor within TSS subprograms and other
-      --  predefined primitives.
+      --  predefined primitives. For a derived type, ensure that the parent
+      --  type is already frozen so that its predicate function has been
+      --  constructed already. This is necessary if the parent is declared
+      --  in a nested package and its own freeze point has not been reached.
 
       if Is_Type (E)
         and then Nongeneric_Case
         and then not Within_Internal_Subprogram
         and then Has_Predicates (E)
       then
+         declare
+            Atyp : constant Entity_Id := Nearest_Ancestor (E);
+         begin
+            if Present (Atyp)
+              and then Has_Predicates (Atyp)
+              and then not Is_Frozen (Atyp)
+            then
+               Freeze_Before (N, Atyp);
+            end if;
+         end;
+
          Build_Predicate_Functions (E, N);
       end if;