[dcc32 Fatal Error]: F2084 Internal Error: NC1921

Question

I'm trying to compile the following code in Delphi Rio:

unit untObjectHelper;

interface

uses
   SysUtils;

type
   TObjectHelper = class(TInterfacedObject)
   public
      class procedure Clone(const objOrigem: TObject; const objDestino: TObject);
   end;

implementation

uses
   System.Rtti;

{ TObjectHelper }

class procedure TObjectHelper.Clone(const objOrigem,
   objDestino: TObject);
begin
   if not Assigned(objOrigem) then
      Exit;

   if not Assigned(objDestino) then
      Exit;

   if objOrigem.ClassType <> objDestino.ClassType then
      Exit;

   var contexto := TRttiContext.Create;
   try
      var tipo := contexto.GetType(objOrigem.ClassType);
      var campos := tipo.GetFields();
   finally
      contexto.Free;
   end;
end;

end.

however the following error occurs:

[dcc32 Fatal Error] untObjectHelper.pas (36): F2084 Internal Error: NC1921

on the line:

var fields: = type.GetFields ();

version: Embarcadero® Delphi 10.3 Version 26.0.33219.4899

I did not find reference to this error, could someone help me? thank you very much

Looks like something you should be reporting to QC. Not surprised with the introduction of in-line variables. Try pre-declaring that variable, or both. Probably a combination of that + RTTI. — Jerry Dodge, May 06 '19 at 13:12
I don't have Rio, but in Seattle, you can't declare a variable named "Type". So, I'd try to rename the variable something else, or use "&Type". — Ken Bourassa, May 06 '19 at 13:19
@JerryDodge you are correct, declaring in the variable section, the code compiled — Passella, May 06 '19 at 13:24

Passella · Accepted Answer · 2019-05-06T17:54:10.860

The problem is the type inference, thanks to Rudy Velthuis for the tip

unit untObjectHelper;

interface

uses
   SysUtils;

type
   TObjectHelper = class(TInterfacedObject)
   public
      class procedure Clone(const objOrigem: TObject; const objDestino: TObject);
   end;

implementation

uses
   System.Rtti;

{ TObjectHelper }

class procedure TObjectHelper.Clone(const objOrigem,
   objDestino: TObject);
begin
   if not Assigned(objOrigem) then
      Exit;

   if not Assigned(objDestino) then
      Exit;

   if objOrigem.ClassType <> objDestino.ClassType then
      Exit;

   var contexto := TRttiContext.Create;
   try
      var tipo := contexto.GetType(objOrigem.ClassType);
      var campos: TArray<TRttiField> := tipo.GetFields();
   finally
      contexto.Free;
   end;
end;

end.

Alternatively, you can use your original code with the following amendment: `var campos: TArray := tipo.GetFields();`. The problem is not the inline declaration, the problem is the type inference, which doesn't work properly. — Rudy Velthuis, May 06 '19 at 16:42

[dcc32 Fatal Error]: F2084 Internal Error: NC1921

1 Answers1