unit HappyButton;

interface

uses classes,
  stdctrls;

type
  TButton = class( stdctrls.TButton )
  public
    function MakeHappy: string;

unit Unit0;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Unit2, Unit1;

type
  TForm0 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form0: TForm0;

implementation


{$R *.dfm}

procedure TForm0.Button1Click(Sender: TObject);
begin
  x;
end;

end.

unit Unit1;

interface

uses Dialogs;

procedure x;

implementation

procedure x;
begin
  ShowMessage('1');
end;

end.

unit Unit2;

interface

uses Dialogs;

procedure x;

implementation

procedure x;
begin
  ShowMessage('2');
end;

end.