CODEWITHSUNDEEP
multithreadingdelphiwarningsdelphi-xeanonymous
Gad D Lord
Gad D Lord

Reputation: 6762

{DCC Warning} W1036 Variable '$frame' might not have been initialized?

Any ideas why I get this warning in Delphi XE:

[DCC Warning] Form1.pas(250): W1036 Variable '$frame' might not have been initialized

procedure TForm1.Action1Execute(Sender: TObject);
var
  Thread: TThread;
begin
  ...
 Thread := TThread.CreateAnonymousThread(
   procedure{Anonymos}()

     procedure ShowLoading(const Show: Boolean);
     begin  /// <-------------            WARNING IS GIVEN FOR THIS LINE (line number 250)
       Thread.Synchronize(Thread,
          procedure{Anonymous}()
          begin
            ...
            Button1.Enabled := not Show;
            ...
          end
        );
     end;

  var
    i: Integer;
  begin
    ShowLoading(true);
    try
      Thread.Synchronize(Thread,
        procedure{Anonymous}()
        begin
          ... // some UI updates
        end
      Thread.Synchronize(Thread,
        procedure{Anonymous}()
        begin
          ... // some UI updates
        end
      );
    finally
      ShowLoading(false);
    end;
  end
  ).NameThread('Some Thread Name');
  Thread.Start;
end;

I do not have anywhere in my code a variable names frame nor $frame. I am even not sure how $frame with $ sign can be a valid identifier.

Smells like compiler magic to me.

PS: Of course the real life xosw is having other than Form1, Button1, Action1 names.

Upvotes: 3

Views: 601

Answers (1)

LU RD
LU RD

Reputation: 34899

In XE2 this compiler warning is not there. Anyway, to make your method a bit clearer to the compiler, try this :

procedure TForm1.Action1Execute(Sender : TObject);
var
  Thread: TThread;
begin
  Thread := TThread.CreateAnonymousThread(
    procedure{Anonymos}()


  Type
    TProcRef = reference to procedure (const Show: Boolean);
  var
    i: Integer;
    ShowLoading : TProcRef;
  begin
    ShowLoading:=
      procedure (const Show: Boolean)
      begin
        Thread.Synchronize(Thread,
          procedure{Anonymous}()
          begin
            // Button1.Enabled := not Show;
          end
        );
     end;

     ShowLoading(true);
    ... // and so on.

Update : I just checked in XE, this really fixes the compiler warning.

The reference I gave in the comment to the question explains about the warning and frame objects. So I guess that the XE compiler is getting confused about the frame object ShowLoading is creating. And creating an explicit reference fixed the warning.

Update 2 :

Just showing my test for your reference :

program Project1;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  Windows,Classes, SysUtils;

procedure Action1Execute;
var
  Thread: TThread;
begin
 Thread := TThread.CreateAnonymousThread(
   procedure{Anonymos}()


  Type
    TProcRef = reference to procedure (const Show: Boolean);
  var
    i: Integer;
    ShowLoading : TProcRef;
  begin
    ShowLoading:=
     procedure (const Show: Boolean)
     begin
       Thread.Synchronize(Thread,
          procedure{Anonymous}()
          begin
            // Button1.Enabled := not Show;
          end
        );
     end;

    ShowLoading(true);
    try
      Thread.Synchronize( Thread,
        procedure{Anonymous}()
        begin
          // some UI updates
        end
      );
      Thread.Synchronize( Thread,
        procedure{Anonymous}()
        begin
          // some UI updates
        end
      );
    finally
      ShowLoading(false);
    end;
  end
  ); //.NameThreadForDebugging('Some Thread Name');

  Thread.Start;
end;

begin
  try
    { TODO -oUser -cConsole Main : Insert code here }
    Action1Execute;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.

Upvotes: 3

Related Questions