Idle Musings of a Delphi Junkie

I've been using both the JCL and JVCL from the wonderful folks at JEDI for a few years now, and was recently reminded why.

I had an unreproducible bug which I had to track down with some debug logging. While there were only one or two points in the code which could cause this particular bug, there were literally hundreds of places in the code which called these routines. With a bit of help from the stack tracing routines in the JCL, I was able to quickly pin down exactly where the problem was originiating. Below is all it took to get the stack trace I required to pinpoint the culprit:

function BuildStackTrace(const ALevel: Integer = 0): string;
var
  sl: TStringList;
  locInfo: TJclLocationInfo;
  procAddr: Pointer;
  i: Integer;
begin
  sl := TStringList.Create;
  try
    i := ALevel;
    procAddr := Caller(i);
    while procAddr <> nil do
    begin
      if GetLocationInfo(procAddr, locInfo) then
        sl.Add(Format('[$%s] %s.%s Line %d',
          [IntToHex(Integer(locInfo.Address), 8), locInfo.UnitName, locInfo.ProcedureName, locInfo.LineNumber]));
        Inc(i);
        procAddr := Caller(i);
    end;
    Result := sl.Text;
  finally
    sl.Free;
  end;
end;

For any Delphi developers who haven't checked out what the JEDI projects have to offer, I strongly recommend you check them out now. And to any JEDI contributors who may be reading this, thanks a bunch and if you're ever in Auckland, look me up and I'll shout you a drink of your favourite poison (with full source code, of course).