[fpc-pascal] Property write access on records

[Ryan Joseph]

> On Mar 7, 2020, at 5:15 AM, Sven Barth <pascaldragon at googlemail.com> wrote:
> 
> I've found two bug reports related to this (I searched for "property" and only those reports that are neither closed nor resolved):
> - https://bugs.freepascal.org/view.php?id=23620
> - https://bugs.freepascal.org/view.php?id=14534
> 
> And I noticed that the following already does generate an error:

Yes, you're right this does trigger the correct error. My example was actually bad because I didn't notice that my problem was coming from a more complex situation.

Given the code I get no error because the "width" property of the helper is writeable but the "point" property is read-only. This should still give the error because even though "width" is writable the "point" is read-only and the assignment will still go to temporary memory, thus failing silently. 

Should I file a new bug report for this?

====================

{$mode objfpc}
{$modeswitch advancedrecords}

program test;

type
  TPoint = record
    x, y: integer;
  end;

type
  TSizeHelper = record helper for TPoint
    procedure SetWidth(newValue: integer); inline;
    procedure SetHeight(newValue: integer); inline;
    function GetWidth: integer; inline;
    function GetHeight: integer; inline;
    property Width: integer read GetWidth write SetWidth;
    property Height: integer read GetHeight write SetHeight;
  end;

procedure TSizeHelper.SetWidth(newValue: integer);
begin
  x := newValue;
end;

procedure TSizeHelper.SetHeight(newValue: integer);
begin
  y := newValue;  
end;

function TSizeHelper.GetWidth: integer;
begin
  result := x;
end;

function TSizeHelper.GetHeight: integer;
begin
  result := y;
end;

type
  TThing = record
    m_point: TPoint;
    function GetPoint: TPoint;
    property point: TPoint read GetPoint;
  end;

function TThing.GetPoint: TPoint;
begin
  result := m_point;
end;

var
  t: TThing;
begin
  // no error!
  t.point.width := 0;
end.


Regards,
	Ryan Joseph