This patch fixes a spurious error on a derived type declaration whose
subtype indication is a subtype of a private type whose full view is a
constrained discriminated type.
Tested on x86_64-pc-linux-gnu, committed on trunk
2019-07-01 Ed Schonberg <schonb...@adacore.com>
gcc/ada/
* sem_ch3.adb (Build_Derived_Record_Type): If the parent type is
declared as a subtype of a private type with an inherited
discriminant constraint, its generated full base appears as a
record subtype, so we need to retrieve its oen base type so that
the inherited constraint can be applied to it.
gcc/testsuite/
* gnat.dg/derived_type6.adb, gnat.dg/derived_type6.ads: New
testcase.--- gcc/ada/sem_ch3.adb
+++ gcc/ada/sem_ch3.adb
@@ -8582,6 +8582,16 @@ package body Sem_Ch3 is
Parent_Base := Base_Type (Parent_Type);
end if;
+ -- If the parent type is declared as a subtype of another private
+ -- type with inherited discriminants, its generated base type is
+ -- itself a record subtype. To further inherit the constraint we
+ -- need to use its own base to have an unconstrained type on which
+ -- to apply the inherited constraint.
+
+ if Ekind (Parent_Base) = E_Record_Subtype then
+ Parent_Base := Base_Type (Parent_Base);
+ end if;
+
-- AI05-0115: if this is a derivation from a private type in some
-- other scope that may lead to invisible components for the derived
-- type, mark it accordingly.
--- /dev/null
new file mode 100644
+++ gcc/testsuite/gnat.dg/derived_type6.adb
@@ -0,0 +1,5 @@
+-- { dg-do compile }
+
+package body Derived_Type6 is
+ procedure Foo is null;
+end Derived_Type6;
--- /dev/null
new file mode 100644
+++ gcc/testsuite/gnat.dg/derived_type6.ads
@@ -0,0 +1,9 @@
+with Ada.Strings.Bounded;
+
+package Derived_Type6 is
+ package b is new Ada.Strings.Bounded.Generic_Bounded_Length(10);
+ subtype s1 is b.Bounded_String;
+ type s2 is new s1;
+
+ procedure Foo;
+end Derived_Type6;
