diff mbox

[Ada] Spurious error on Default_Initial_Condition

Message ID 20170120103219.GA74180@adacore.com
State New
Headers show

Commit Message

Arnaud Charlet Jan. 20, 2017, 10:32 a.m. UTC
This patch modifies the generation of the Default_Initial_Condition procedure
to disregard class-wide types and the underlying full views of private types.
In addition, the patch preserves the attributes of freeze nodes when the
partial and/or full views of a private type inherit the freeze node of the
underlying full view.

------------
-- Source --
------------

--  pack_1.ads

package Pack_1 is
   type Untag_Par (Size : Natural) is private
     with Default_Initial_Condition => Is_OK_UP (Untag_Par);

   type Tag_Par (Size : Natural) is tagged private
     with Default_Initial_Condition => Is_OK_TP (Tag_Par);

   type Lim_Untag_Par (Size : Natural) is limited private
     with Default_Initial_Condition => Is_OK_LUP (Lim_Untag_Par);

   type Lim_Tag_Par (Size : Natural) is tagged limited private
     with Default_Initial_Condition => Is_OK_LTP (Lim_Tag_Par);

   function Is_OK_UP  (Obj : Untag_Par)     return Boolean;
   function Is_OK_TP  (Obj : Tag_Par)       return Boolean;
   function Is_OK_LUP (Obj : Lim_Untag_Par) return Boolean;
   function Is_OK_LTP (Obj : Lim_Tag_Par)   return Boolean;

private
   type Untag_Par (Size : Natural) is record
      Comp : Natural := Size;
   end record;

   type Tag_Par (Size : Natural) is tagged record
      Comp : Natural := Size;
   end record;

   type Lim_Untag_Par (Size : Natural) is limited record
      Comp : Natural := Size;
   end record;

   type Lim_Tag_par (Size : Natural) is tagged limited record
      Comp : Natural := Size;
   end record;
end Pack_1;

--  pack_1.adb

with Ada.Text_IO; use Ada.Text_IO;

package body Pack_1 is
   function Is_OK_UP (Obj : Untag_Par) return Boolean is
   begin
      Put_Line ("Untag_Par");
      return True;
   end Is_OK_UP;

   function Is_OK_TP (Obj : Tag_Par) return Boolean is
   begin
      Put_Line ("Tag_Par");
      return True;
   end Is_OK_TP;

   function Is_OK_LUP (Obj : Lim_Untag_Par) return Boolean is
   begin
      Put_Line ("Lim_Untag_Par");
      return True;
   end Is_OK_LUP;

   function Is_OK_LTP (Obj : Lim_Tag_Par) return Boolean is
   begin
      Put_Line ("Lim_Tag_Par");
      return True;
   end Is_OK_LTP;
end Pack_1;

--  pack_2.ads

with Pack_1; use Pack_1;

package Pack_2 is
   type Deriv_1 is private
     with Default_Initial_Condition => Is_OK_Deriv_1 (Deriv_1);

   type Deriv_2 is tagged private
     with Default_Initial_Condition => Is_OK_Deriv_2 (Deriv_2);

   type Deriv_3 is limited private
     with Default_Initial_Condition => Is_OK_Deriv_3 (Deriv_3);

   type Deriv_4 is tagged limited private
     with Default_Initial_Condition => Is_OK_Deriv_4 (Deriv_4);

   type Deriv_5 is private
     with Default_Initial_Condition;

   type Deriv_6 is tagged private
     with Default_Initial_Condition;

   type Deriv_7 is limited private
     with Default_Initial_Condition;

   type Deriv_8 is tagged limited private
     with Default_Initial_Condition;

   function Is_OK_Deriv_1 (Obj : Deriv_1) return Boolean;
   function Is_OK_Deriv_2 (Obj : Deriv_2) return Boolean;
   function Is_OK_Deriv_3 (Obj : Deriv_3) return Boolean;
   function Is_OK_Deriv_4 (Obj : Deriv_4) return Boolean;

private
   type Deriv_1 is new Untag_Par     (1);
   type Deriv_2 is new Tag_Par       (2) with null record;
   type Deriv_3 is new Lim_Untag_Par (3);
   type Deriv_4 is new Lim_Tag_Par   (4) with null record;
   type Deriv_5 is new Untag_Par     (5);
   type Deriv_6 is new Tag_Par       (6) with null record;
   type Deriv_7 is new Lim_Untag_Par (7);
   type Deriv_8 is new Lim_Tag_Par   (8) with null record;

end Pack_2;

--  pack_2.adb

with Ada.Text_IO; use Ada.Text_IO;

package body Pack_2 is
   function Is_OK_Deriv_1 (Obj : Deriv_1) return Boolean is
   begin
      Put_Line ("Deriv_1");
      return True;
   end Is_OK_Deriv_1;

   function Is_OK_Deriv_2 (Obj : Deriv_2) return Boolean is
   begin
      Put_Line ("Deriv_2");
      return True;
   end Is_OK_Deriv_2;

   function Is_OK_Deriv_3 (Obj : Deriv_3) return Boolean is
   begin
      Put_Line ("Deriv_3");
      return True;
   end Is_OK_Deriv_3;

   function Is_OK_Deriv_4 (Obj : Deriv_4) return Boolean is
   begin
      Put_Line ("Deriv_4");
      return True;
   end Is_OK_Deriv_4;
end Pack_2;

--  main.adb

with Pack_2; use Pack_2;

procedure Main is
   Obj_1 : Deriv_1;
   Obj_2 : Deriv_2;
   Obj_3 : Deriv_3;
   Obj_4 : Deriv_4;
   Obj_5 : Deriv_5;
   Obj_6 : Deriv_6;
   Obj_7 : Deriv_7;
   Obj_8 : Deriv_8;
begin
   null;
end Main;

----------------------------
-- Compilation and output --
----------------------------

$ gnatmake -q -gnata main.adb
$ ./main
Deriv_1
Deriv_2
Deriv_3
Deriv_4

Tested on x86_64-pc-linux-gnu, committed on trunk

2017-01-20  Hristian Kirtchev  <kirtchev@adacore.com>

	* einfo.adb Flag298 now denotes Is_Underlying_Full_View.
	(Is_Underlying_Full_View): New routine.
	(Set_Is_Underlying_Full_View): New routine.
	(Write_Entity_Flags): Add an entry for Is_Underlying_Full_View.
	* einfo.ads Add new attribute Is_Underlying_Full_View.
	(Is_Underlying_Full_View): New routine along with pragma Inline.
	(Set_Is_Underlying_Full_View): New routine along with pragma Inline.
	* exp_util.adb (Build_DIC_Procedure_Body): Do not consider
	class-wide types and underlying full views. The first subtype
	is used as the working type for all Itypes, not just array base types.
	(Build_DIC_Procedure_Declaration): Do not consider
	class-wide types and underlying full views. The first subtype
	is used as the working type for all Itypes, not just array
	base types.
	* freeze.adb (Freeze_Entity): Inherit the freeze node of a full
	view or an underlying full view without clobbering the attributes
	of a previous freeze node.
	(Inherit_Freeze_Node): New routine.
	* sem_ch3.adb (Build_Derived_Private_Type): Mark an underlying
	full view as such.
	(Build_Underlying_Full_View): Mark an underlying full view as such.
	* sem_ch7.adb (Install_Private_Declarations): Mark an underlying
	full view as such.
diff mbox

Patch

Index: sem_ch3.adb
===================================================================
--- sem_ch3.adb	(revision 244691)
+++ sem_ch3.adb	(working copy)
@@ -7444,6 +7444,7 @@ 
                   Set_Full_View (Derived_Type, Full_Der);
                else
                   Set_Underlying_Full_View (Derived_Type, Full_Der);
+                  Set_Is_Underlying_Full_View (Full_Der);
                end if;
 
                if not Is_Base_Type (Derived_Type) then
@@ -7501,6 +7502,7 @@ 
             Set_Full_View (Derived_Type, Full_Der);
          else
             Set_Underlying_Full_View (Derived_Type, Full_Der);
+            Set_Is_Underlying_Full_View (Full_Der);
          end if;
 
          --  In any case, the primitive operations are inherited from the
@@ -7607,6 +7609,7 @@ 
             else
                Build_Full_Derivation;
                Set_Underlying_Full_View (Derived_Type, Full_Der);
+               Set_Is_Underlying_Full_View (Full_Der);
             end if;
 
             --  The full view will be used to swap entities on entry/exit to
@@ -10018,6 +10021,7 @@ 
 
       Analyze (Indic);
       Set_Underlying_Full_View (Typ, Full_View (Subt));
+      Set_Is_Underlying_Full_View (Full_View (Subt));
    end Build_Underlying_Full_View;
 
    -------------------------------
Index: exp_util.adb
===================================================================
--- exp_util.adb	(revision 244691)
+++ exp_util.adb	(working copy)
@@ -1736,13 +1736,24 @@ 
    --  Start of processing for Build_DIC_Procedure_Body
 
    begin
-      Work_Typ := Typ;
+      Work_Typ := Base_Type (Typ);
 
-      --  The input type denotes the implementation base type of a constrained
-      --  array type. Work with the first subtype as the DIC pragma is on its
-      --  rep item chain.
+      --  Do not process class-wide types as these are Itypes, but lack a first
+      --  subtype (see below).
 
-      if Ekind (Work_Typ) = E_Array_Type and then Is_Itype (Work_Typ) then
+      if Is_Class_Wide_Type (Work_Typ) then
+         return;
+
+      --  Do not process the underlying full view of a private type. There is
+      --  no way to get back to the partial view, plus the body will be built
+      --  by the full view or the base type.
+
+      elsif Is_Underlying_Full_View (Work_Typ) then
+         return;
+
+      --  Use the first subtype when dealing with various base types
+
+      elsif Is_Itype (Work_Typ) then
          Work_Typ := First_Subtype (Work_Typ);
 
       --  The input denotes the corresponding record type of a protected or a
@@ -1964,13 +1975,24 @@ 
       --  The working type
 
    begin
-      Work_Typ := Typ;
+      Work_Typ := Base_Type (Typ);
 
-      --  The input type denotes the implementation base type of a constrained
-      --  array type. Work with the first subtype as the DIC pragma is on its
-      --  rep item chain.
+      --  Do not process class-wide types as these are Itypes, but lack a first
+      --  subtype (see below).
 
-      if Ekind (Work_Typ) = E_Array_Type and then Is_Itype (Work_Typ) then
+      if Is_Class_Wide_Type (Work_Typ) then
+         return;
+
+      --  Do not process the underlying full view of a private type. There is
+      --  no way to get back to the partial view, plus the body will be built
+      --  by the full view or the base type.
+
+      elsif Is_Underlying_Full_View (Work_Typ) then
+         return;
+
+      --  Use the first subtype when dealing with various base types
+
+      elsif Is_Itype (Work_Typ) then
          Work_Typ := First_Subtype (Work_Typ);
 
       --  The input denotes the corresponding record type of a protected or a
Index: sem_ch7.adb
===================================================================
--- sem_ch7.adb	(revision 244691)
+++ sem_ch7.adb	(working copy)
@@ -2178,6 +2178,7 @@ 
                then
                   Set_Full_View (Id, Underlying_Full_View (Full));
                   Set_Underlying_Full_View (Id, Full);
+                  Set_Is_Underlying_Full_View (Full);
 
                   Set_Underlying_Full_View (Full, Empty);
                   Set_Is_Frozen (Full_View (Id));
Index: einfo.adb
===================================================================
--- einfo.adb	(revision 244691)
+++ einfo.adb	(working copy)
@@ -614,8 +614,8 @@ 
    --    Is_Ignored_Transient            Flag295
    --    Has_Partial_Visible_Refinement  Flag296
    --    Is_Entry_Wrapper                Flag297
+   --    Is_Underlying_Full_View         Flag298
 
-   --    (unused)                        Flag298
    --    (unused)                        Flag299
    --    (unused)                        Flag300
 
@@ -2612,6 +2612,11 @@ 
       return Flag117 (Implementation_Base_Type (Id));
    end Is_Unchecked_Union;
 
+   function Is_Underlying_Full_View (Id : E) return B is
+   begin
+      return Flag298 (Id);
+   end Is_Underlying_Full_View;
+
    function Is_Underlying_Record_View (Id : E) return B is
    begin
       return Flag246 (Id);
@@ -5709,6 +5714,12 @@ 
       Set_Flag117 (Id, V);
    end Set_Is_Unchecked_Union;
 
+   procedure Set_Is_Underlying_Full_View (Id : E; V : B := True) is
+   begin
+      pragma Assert (Is_Type (Id));
+      Set_Flag298 (Id, V);
+   end Set_Is_Underlying_Full_View;
+
    procedure Set_Is_Underlying_Record_View (Id : E; V : B := True) is
    begin
       pragma Assert (Ekind (Id) = E_Record_Type);
@@ -9457,6 +9468,7 @@ 
       W ("Is_Trivial_Subprogram",           Flag235 (Id));
       W ("Is_True_Constant",                Flag163 (Id));
       W ("Is_Unchecked_Union",              Flag117 (Id));
+      W ("Is_Underlying_Full_View",         Flag298 (Id));
       W ("Is_Underlying_Record_View",       Flag246 (Id));
       W ("Is_Unimplemented",                Flag284 (Id));
       W ("Is_Unsigned_Type",                Flag144 (Id));
Index: einfo.ads
===================================================================
--- einfo.ads	(revision 244691)
+++ einfo.ads	(working copy)
@@ -3236,6 +3236,11 @@ 
 --       Defined in all entities. Set only in record types to which the
 --       pragma Unchecked_Union has been validly applied.
 
+--    Is_Underlying_Full_View (Flag298)
+--       Defined in all entities. Set for types which represent the true full
+--       view of a private type completed by another private type. For further
+--       details, see attribute Underlying_Full_View.
+
 --    Is_Underlying_Record_View (Flag246) [base type only]
 --       Defined in all entities. Set only in record types that represent the
 --       underlying record view. This view is built for derivations of types
@@ -7183,6 +7188,7 @@ 
    function Is_Trivial_Subprogram               (Id : E) return B;
    function Is_True_Constant                    (Id : E) return B;
    function Is_Unchecked_Union                  (Id : E) return B;
+   function Is_Underlying_Full_View             (Id : E) return B;
    function Is_Underlying_Record_View           (Id : E) return B;
    function Is_Unimplemented                    (Id : E) return B;
    function Is_Unsigned_Type                    (Id : E) return B;
@@ -7868,6 +7874,7 @@ 
    procedure Set_Is_Trivial_Subprogram           (Id : E; V : B := True);
    procedure Set_Is_True_Constant                (Id : E; V : B := True);
    procedure Set_Is_Unchecked_Union              (Id : E; V : B := True);
+   procedure Set_Is_Underlying_Full_View         (Id : E; V : B := True);
    procedure Set_Is_Underlying_Record_View       (Id : E; V : B := True);
    procedure Set_Is_Unimplemented                (Id : E; V : B := True);
    procedure Set_Is_Unsigned_Type                (Id : E; V : B := True);
@@ -8705,6 +8712,7 @@ 
    pragma Inline (Is_True_Constant);
    pragma Inline (Is_Type);
    pragma Inline (Is_Unchecked_Union);
+   pragma Inline (Is_Underlying_Full_View);
    pragma Inline (Is_Underlying_Record_View);
    pragma Inline (Is_Unimplemented);
    pragma Inline (Is_Unsigned_Type);
@@ -9180,6 +9188,7 @@ 
    pragma Inline (Set_Is_Trivial_Subprogram);
    pragma Inline (Set_Is_True_Constant);
    pragma Inline (Set_Is_Unchecked_Union);
+   pragma Inline (Set_Is_Underlying_Full_View);
    pragma Inline (Set_Is_Underlying_Record_View);
    pragma Inline (Set_Is_Unimplemented);
    pragma Inline (Set_Is_Unsigned_Type);
Index: freeze.adb
===================================================================
--- freeze.adb	(revision 244691)
+++ freeze.adb	(working copy)
@@ -2087,6 +2087,12 @@ 
       --  Determine whether an arbitrary entity is subject to Boolean aspect
       --  Import and its value is specified as True.
 
+      procedure Inherit_Freeze_Node
+        (Fnod : Node_Id;
+         Typ  : Entity_Id);
+      --  Set type Typ's freeze node to refer to Fnode. This routine ensures
+      --  that any attributes attached to Typ's original node are preserved.
+
       procedure Wrap_Imported_Subprogram (E : Entity_Id);
       --  If E is an entity for an imported subprogram with pre/post-conditions
       --  then this procedure will create a wrapper to ensure that proper run-
@@ -4726,6 +4732,60 @@ 
          return False;
       end Has_Boolean_Aspect_Import;
 
+      -------------------------
+      -- Inherit_Freeze_Node --
+      -------------------------
+
+      procedure Inherit_Freeze_Node
+        (Fnod : Node_Id;
+         Typ  : Entity_Id)
+      is
+         Typ_Fnod : constant Node_Id := Freeze_Node (Typ);
+
+      begin
+         Set_Freeze_Node (Typ, Fnod);
+         Set_Entity (Fnod, Typ);
+
+         --  The input type had an existing node. Propagate relevant attributes
+         --  from the old freeze node to the inherited freeze node.
+
+         --  ??? if both freeze nodes have attributes, would they differ?
+
+         if Present (Typ_Fnod) then
+
+            --  Attribute Access_Types_To_Process
+
+            if Present (Access_Types_To_Process (Typ_Fnod))
+              and then No (Access_Types_To_Process (Fnod))
+            then
+               Set_Access_Types_To_Process (Fnod,
+                 Access_Types_To_Process (Typ_Fnod));
+            end if;
+
+            --  Attribute Actions
+
+            if Present (Actions (Typ_Fnod)) and then No (Actions (Fnod)) then
+               Set_Actions (Fnod, Actions (Typ_Fnod));
+            end if;
+
+            --  Attribute First_Subtype_Link
+
+            if Present (First_Subtype_Link (Typ_Fnod))
+              and then No (First_Subtype_Link (Fnod))
+            then
+               Set_First_Subtype_Link (Fnod, First_Subtype_Link (Typ_Fnod));
+            end if;
+
+            --  Attribute TSS_Elist
+
+            if Present (TSS_Elist (Typ_Fnod))
+              and then No (TSS_Elist (Fnod))
+            then
+               Set_TSS_Elist (Fnod, TSS_Elist (Typ_Fnod));
+            end if;
+         end if;
+      end Inherit_Freeze_Node;
+
       ------------------------------
       -- Wrap_Imported_Subprogram --
       ------------------------------
@@ -5776,9 +5836,9 @@ 
                         F_Node := Freeze_Node (Full);
 
                         if Present (F_Node) then
-                           Set_Freeze_Node (Full_View (E), F_Node);
-                           Set_Entity (F_Node, Full_View (E));
-
+                           Inherit_Freeze_Node
+                             (Fnod => F_Node,
+                              Typ  => Full_View (E));
                         else
                            Set_Has_Delayed_Freeze (Full_View (E), False);
                            Set_Freeze_Node (Full_View (E), Empty);
@@ -5789,9 +5849,9 @@ 
                         F_Node := Freeze_Node (Full_View (E));
 
                         if Present (F_Node) then
-                           Set_Freeze_Node (E, F_Node);
-                           Set_Entity (F_Node, E);
-
+                           Inherit_Freeze_Node
+                             (Fnod => F_Node,
+                              Typ  => E);
                         else
                            --  {Incomplete,Private}_Subtypes with Full_Views
                            --  constrained by discriminants.
@@ -5847,9 +5907,9 @@ 
                   F_Node := Freeze_Node (Underlying_Full_View (E));
 
                   if Present (F_Node) then
-                     Set_Freeze_Node (E, F_Node);
-                     Set_Entity (F_Node, E);
-
+                     Inherit_Freeze_Node
+                       (Fnod => F_Node,
+                        Typ  => E);
                   else
                      Set_Has_Delayed_Freeze (E, False);
                      Set_Freeze_Node (E, Empty);