AI05-019 specifies the conditions under which freezing a subprogram also
freezes the profile of the subprogram. Prior to this patch the profile was
frozen unconditionally, leading to spurious errors.
Examples in ACATS test BDD2004.
Tested on x86_64-pc-linux-gnu, committed on trunk
2016-04-21 Ed Schonberg <schonb...@adacore.com>
* freeze.ads, freeze.adb (Freeze_Entity, Freeze_Before): Add
boolean parameter to determine whether freezing an overloadable
entity freezes its profile as well. This is required by
AI05-019. The call to Freeze_Profile within Freeze_Entity is
conditioned by the value of this flag, whose default is True.
* sem_attr.adb (Resolve_Attribute, case 'Access): The attribute
reference freezes the prefix, but it the prefix is a subprogram
it does not freeze its profile.
Index: freeze.adb
===================================================================
--- freeze.adb (revision 235267)
+++ freeze.adb (working copy)
@@ -6,7 +6,7 @@
-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -1908,9 +1908,17 @@
-- Freeze_Before --
-------------------
- procedure Freeze_Before (N : Node_Id; T : Entity_Id) is
- Freeze_Nodes : constant List_Id := Freeze_Entity (T, N);
+ procedure Freeze_Before
+ (N : Node_Id;
+ T : Entity_Id;
+ F_P : Boolean := True)
+ is
+ -- Freeze T, then insert the generated Freeze nodes before the node N.
+ -- The flag F_P is used when T is an overloadable entity, and indicates
+ -- whether its profile should be frozen at the same time.
+ Freeze_Nodes : constant List_Id := Freeze_Entity (T, N, F_P);
+
begin
if Ekind (T) = E_Function then
Check_Expression_Function (N, T);
@@ -1925,7 +1933,11 @@
-- Freeze_Entity --
-------------------
- function Freeze_Entity (E : Entity_Id; N : Node_Id) return List_Id is
+ function Freeze_Entity
+ (E : Entity_Id;
+ N : Node_Id;
+ F_P : Boolean := True) return List_Id
+ is
Loc : constant Source_Ptr := Sloc (N);
Atype : Entity_Id;
Comp : Entity_Id;
@@ -4990,12 +5002,13 @@
-- In Ada 2012, freezing a subprogram does not always freeze
-- the corresponding profile (see AI05-019). An attribute
- -- reference is not a freezing point of the profile.
+ -- reference is not a freezing point of the profile. The boolean
+ -- Flag F_P indicates whether the profile should be frozen now.
-- Other constructs that should not freeze ???
-- This processing doesn't apply to internal entities (see below)
- if not Is_Internal (E) then
+ if not Is_Internal (E) and then F_P then
if not Freeze_Profile (E) then
Ghost_Mode := Save_Ghost_Mode;
return Result;
Index: freeze.ads
===================================================================
--- freeze.ads (revision 235192)
+++ freeze.ads (working copy)
@@ -6,7 +6,7 @@
-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -187,13 +187,19 @@
-- If Initialization_Statements (E) is an N_Compound_Statement, insert its
-- actions in the enclosing list and reset the attribute.
- function Freeze_Entity (E : Entity_Id; N : Node_Id) return List_Id;
+ function Freeze_Entity
+ (E : Entity_Id;
+ N : Node_Id;
+ F_P : Boolean := True) return List_Id;
-- Freeze an entity, and return Freeze nodes, to be inserted at the point
-- of call. N is a node whose source location corresponds to the freeze
-- point. This is used in placing warning messages in the situation where
-- it appears that a type has been frozen too early, e.g. when a primitive
-- operation is declared after the freezing point of its tagged type.
-- Returns No_List if no freeze nodes needed.
+ -- The defaulted parameter F_P is used when E is a subprogram, and
+ -- determines whether the profile of the subprogram should be frozen as
+ -- well.
procedure Freeze_All (From : Entity_Id; After : in out Node_Id);
-- Before a non-instance body, or at the end of a declarative part,
@@ -209,8 +215,13 @@
-- in the scope. It is used to prevent a quadratic traversal over already
-- frozen entities.
- procedure Freeze_Before (N : Node_Id; T : Entity_Id);
+ procedure Freeze_Before
+ (N : Node_Id;
+ T : Entity_Id;
+ F_P : Boolean := True);
-- Freeze T then Insert the generated Freeze nodes before the node N
+ -- The flag F_P is used when T is an overloadable entity, and indicates
+ -- whether its profile should be frozen at the same time.
procedure Freeze_Expression (N : Node_Id);
-- Freezes the required entities when the Expression N causes freezing.
Index: sem_attr.adb
===================================================================
--- sem_attr.adb (revision 235267)
+++ sem_attr.adb (working copy)
@@ -6,7 +6,7 @@
-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -10161,18 +10161,20 @@
end loop;
-- If Prefix is a subprogram name, this reference freezes,
- -- but not if within spec expression mode
+ -- but not if within spec expression mode. The profile of
+ -- the subprogram is not frozen at this point.
if not In_Spec_Expression then
- Freeze_Before (N, Entity (P));
+ Freeze_Before (N, Entity (P), False);
end if;
- -- If it is a type, there is nothing to resolve. If it is an
- -- object, complete its resolution.
+ -- If it is a type, there is nothing to resolve.
+ -- If it is a subprogram, do not freeze its profile.
+ -- If it is an object, complete its resolution.
elsif Is_Overloadable (Entity (P)) then
if not In_Spec_Expression then
- Freeze_Before (N, Entity (P));
+ Freeze_Before (N, Entity (P), False);
end if;
-- Nothing to do if prefix is a type name
