ada: Storage_Error in indirect call to function returning limited type

At runtime the code generated by the compiler reports the
exception Storage_Error in an indirect call through an
access-to-subprogram variable that references a function
returning a limited tagged type object.

gcc/ada/

	* sem_ch6.adb (Might_Need_BIP_Task_Actuals): Add support
	for access-to-subprogram parameter types.
	* exp_ch6.adb (Add_Task_Actuals_To_Build_In_Place_Call):
	Add dummy BIP parameters to access-to-subprogram types
	that may reference a function that has BIP parameters.

2 files changed, 15 insertions, 8 deletions

diff --git a/gcc/ada/exp_ch6.adb b/gcc/ada/exp_ch6.adb
index b5c5865..005210c 100644
--- a/gcc/ada/exp_ch6.adb
+++ b/gcc/ada/exp_ch6.adb
@@ -642,15 +642,20 @@ package body Exp_Ch6 is
       Master_Formal : Node_Id;
 
    begin
+      pragma Assert (Ekind (Function_Id) in E_Function
+                                          | E_Subprogram_Type);
+
       --  No such extra parameters are needed if there are no tasks
 
       if not Needs_BIP_Task_Actuals (Function_Id) then
 
          --  However we must add dummy extra actuals if the function is
-         --  a dispatching operation that inherited these extra formals.
+         --  a dispatching operation that inherited these extra formals
+         --  or an access-to-subprogram type that requires these extra
+         --  actuals.
 
-         if Is_Dispatching_Operation (Function_Id)
-           and then Has_BIP_Extra_Formal (Function_Id, BIP_Task_Master)
+         if Has_BIP_Extra_Formal (Function_Id, BIP_Task_Master,
+              Must_Be_Frozen => False)
          then
             Master_Formal :=
               Build_In_Place_Formal (Function_Id, BIP_Task_Master);
diff --git a/gcc/ada/sem_ch6.adb b/gcc/ada/sem_ch6.adb
index ca40b54..50dac5c 100644
--- a/gcc/ada/sem_ch6.adb
+++ b/gcc/ada/sem_ch6.adb
@@ -8663,9 +8663,12 @@ package body Sem_Ch6 is
       --  Determines if E has its extra formals
 
       function Might_Need_BIP_Task_Actuals (E : Entity_Id) return Boolean;
-      --  Determines if E is a dispatching primitive returning a limited tagged
-      --  type object since some descendant might return an object with tasks
-      --  (and therefore need the BIP task extra actuals).
+      --  Determines if E is a function or an access to a function returning a
+      --  limited tagged type object. On dispatching primitives this predicate
+      --  is used to determine if some descendant of the function might return
+      --  an object with tasks (and therefore need the BIP task extra actuals).
+      --  On access-to-subprogram types it is used to determine if the target
+      --  function might return an object with tasks.
 
       function Needs_Accessibility_Check_Extra
         (E      : Entity_Id;
@@ -8786,9 +8789,8 @@ package body Sem_Ch6 is
 
          Func_Typ := Root_Type (Underlying_Type (Etype (Subp_Id)));
 
-         return Ekind (Subp_Id) = E_Function
+         return Ekind (Subp_Id) in E_Function | E_Subprogram_Type
            and then not Has_Foreign_Convention (Func_Typ)
-           and then Is_Dispatching_Operation (Subp_Id)
            and then Is_Tagged_Type (Func_Typ)
            and then Is_Limited_Type (Func_Typ)
            and then not Has_Aspect (Func_Typ, Aspect_No_Task_Parts);