Internal Error 20060521 with latest Lazarus build

[eny]

VIL 264; lazarus daily snapshot 26788 (July 23rd) with FPC 2.4.3 on WinXP SP3.
When adding some units to the uses list (Imaging, ImagingTypes, ImagingClasses, ImagingCanvases) an internal error is raised on line 705 of ImagingPSD.

[Galfar]

Report internal compiler error to FPC bug tracker please, there's not much I can do about this.
Or could you try some other FPC versions too?

[eny]

I've found a surprisinlgy simple workaround for this problem.
It seems the compiler is confused by the TLongWordRec usage in SwapEndianLongWord (ImagingUtility.pas) together with a call to this function with a pure constant value parameter:

Code Select Expand


      LongVal := SwapEndianLongWord(16);               // Extra data size (4 (mask size) + 4 (ranges size) + 8 (name))
It's perfectly good syntax, but the compiler gets confused and raises an internal error.

I've found 2 different ways of implementing a quick fix that both work (as far as I can see):
1. Create a simple variant record type and use that as a typecast instead of TLongWordRec.

Code Select Expand

TSimpleLWRec = packed record
  B0, B1, B2, B3: byte;
end;
...
  // In SwapEndianLongWord:
  TSimpleLWRec(Result).B0 = TSimpleLWRec(Value).B3;
  TSimpleLWRec(Result).B1 = TSimpleLWRec(Value).B2;
  //etc...


2. Cheat on the compiler by not passing '16' as an argument, but use a local variable instead:

Code Select Expand

      LongVal := 16;
      LongVal := SwapEndianLongWord(LongVal);               // Extra data size (4 (mask size) + 4 (ranges size) + 8 (name))

LongVal is already there and the assignment introduces little overhead.

[Galfar]

Thanks for the tip for avoiding internal error.
Have you reported it to FPC bug tracker?