XE3: Internal Error G9413

Today I wanted to check whether the OmniThreadLibrary plays nice with XE3 (yes, I know, I’ve should have done this weeks ago, but there was simply not enough time) and I was completely surprised when OtlSync unit couldn’t be compiled due to an internal error G9413.

One hour later I have reduced the problem to a simple test case (below) and to a simple fix. So the OmniThreadLibrary will be supported in the XE3 (as we all hoped for).

For other poor souls that may have run into this problem, here’s a small test case and a workaround.

implementation

uses
    RTTI;

type
    TTest<T> = class
        procedure Test;
    end;

var
    a: IInterface;

procedure TTest<T>.Test;
var
    aMethCreate: TRttiMethod;
begin
    if Length(aMethCreate.GetParameters) = 0 then
    ;
end;

initialization
    a := nil; // F2084 Internal Error: G9413
end.

The problem here is that the G9413 internal error is not reported on the line which causes the problem. The real culprit here is the ‘if Length(aMethCreate.GetParameters)’ call in the ‘TTest<T>.Test’ method.

To fix the problem it is enough to introduce a temporary variable that stores the result of the GetParameters call.

unit Unit136;

interface

implementation

uses
    RTTI;

type
    TTest<T> = class
        procedure Test;
    end;

var
    a: IInterface;

procedure TTest<T>.Test;
var
    aMethCreate: TRttiMethod;
    params     : TArray<TRttiParameter>;
begin
    params := aMethCreate.GetParameters;
    if Length(params) = 0 then
        ;
end;

initialization
    a := nil;
end.

The problem is reported as QC #108942.