Patchwork [Ada] Class-wide objects and debugging information

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Submitter Arnaud Charlet
Date Jan. 3, 2013, 10:49 a.m.
Message ID <20130103104938.GA7548@adacore.com>
Download mbox | patch
Permalink /patch/209214/
State New
Headers show

Comments

Arnaud Charlet - Jan. 3, 2013, 10:49 a.m.
If an object has a class-wide type and a renaming declaration is created for it,
the original object and the one in the renaming declaration are exchanged so
that source information is consistent. The exchange must preserve the entity
chain, which already contains generated internal types. This ensures that
freezing actions are properly generated for all objects declared subsequently
in the same scope, and that debugging information is generated for them.

No simple example available.

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

2013-01-03  Ed Schonberg  <schonberg@adacore.com>

	* exp_ch3.adb (Expand_N_Object_Declaration): If the object has
	a class-wide type and a renaming declaration is created for it,
	preserve entity chain, which already contains generated internal
	types. This ensures that freezing actions are properly generated
	for all objects declared subsequently in the same scope, and
	that debugging information is generated for them.
	* sem_util.adb, sem_util.ads (we): New debugging routine, to
	display entity chain of a given scope.

Patch

Index: sem_ch8.adb
===================================================================
--- sem_ch8.adb	(revision 194841)
+++ sem_ch8.adb	(working copy)
@@ -8531,4 +8531,21 @@ 
       end loop;
    end ws;
 
+   --------
+   -- we --
+   --------
+
+   procedure we (S : Entity_Id) is
+      E : Entity_Id;
+   begin
+      E := First_Entity (S);
+      while Present (E) loop
+         Write_Int (Int (E));
+         Write_Str (" === ");
+         Write_Name (Chars (E));
+         Write_Eol;
+
+         Next_Entity (E);
+      end loop;
+   end we;
 end Sem_Ch8;
Index: sem_ch8.ads
===================================================================
--- sem_ch8.ads	(revision 194841)
+++ sem_ch8.ads	(working copy)
@@ -169,4 +169,7 @@ 
    procedure ws;
    --  Debugging routine for use in gdb: dump all entities on scope stack
 
+   procedure we (S : Entity_Id);
+   --  Debugging routine for use in gdb: dump all entities in given scope
+
 end Sem_Ch8;
Index: exp_ch3.adb
===================================================================
--- exp_ch3.adb	(revision 194841)
+++ exp_ch3.adb	(working copy)
@@ -5315,33 +5315,38 @@ 
                       Subtype_Mark        => New_Occurrence_Of (Typ, Loc),
                       Name => Convert_Tag_To_Interface (Typ, Tag_Comp)));
 
-                  --  If the original entity comes from source, then mark the
-                  --  new entity as needing debug information, even though it's
-                  --  defined by a generated renaming that does not come from
-                  --  source, so that Materialize_Entity will be set on the
-                  --  entity when Debug_Renaming_Declaration is called during
-                  --  analysis.
-
-                  if Comes_From_Source (Def_Id) then
-                     Set_Debug_Info_Needed (Defining_Identifier (N));
-                  end if;
-
                   Analyze (N, Suppress => All_Checks);
 
                   --  Replace internal identifier of rewritten node by the
                   --  identifier found in the sources. We also have to exchange
                   --  entities containing their defining identifiers to ensure
                   --  the correct replacement of the object declaration by this
-                  --  object renaming declaration ---because these identifiers
+                  --  object renaming declaration because these identifiers
                   --  were previously added by Enter_Name to the current scope.
                   --  We must preserve the homonym chain of the source entity
                   --  as well. We must also preserve the kind of the entity,
-                  --  which may be a constant.
+                  --  which may be a constant. Preserve entity chain because
+                  --  itypes may have been generated already, and the full
+                  --  chain must be preserved for final freezing. Finally,
+                  --  Preserve Comes_From_Source setting, so that debugging
+                  --  and cross-referencing information is properly kept.
 
-                  Set_Chars (Defining_Identifier (N), Chars (Def_Id));
-                  Set_Homonym (Defining_Identifier (N), Homonym (Def_Id));
-                  Set_Ekind (Defining_Identifier (N), Ekind (Def_Id));
-                  Exchange_Entities (Defining_Identifier (N), Def_Id);
+                  declare
+                     New_Id    : constant Entity_Id := Defining_Identifier (N);
+                     Next_Temp : constant Entity_Id := Next_Entity (New_Id);
+                     S_Flag    : constant Boolean   :=
+                                   Comes_From_Source (Def_Id);
+
+                  begin
+                     Set_Next_Entity (New_Id, Next_Entity (Def_Id));
+                     Set_Next_Entity (Def_Id, Next_Temp);
+                     Set_Chars (Defining_Identifier (N), Chars (Def_Id));
+                     Set_Homonym (Defining_Identifier (N), Homonym (Def_Id));
+                     Set_Ekind (Defining_Identifier (N), Ekind (Def_Id));
+                     Set_Comes_From_Source (Def_Id, False);
+                     Exchange_Entities (Defining_Identifier (N), Def_Id);
+                     Set_Comes_From_Source (Def_Id, S_Flag);
+                  end;
                end;
             end if;