Peganza - Blog

Can you find this Delphi coding error (part 13)?

January 22, 2024

Can you spot the error in the following (rather constructed) Delphi code extract?

..
function GetSum(L : TList) : Integer;
var  
  I : Integer;
begin
  if IsValid(L) then
  begin
    Result := 0;

    for I := 0 to L.Count-1 do
	  Result := Result+GetValue(L[I]);
  end;
end;
..

This was quite easy, right?

Solution: The result variable (Result) for the function GetSum has an undetermined arbitrary value in one of the possible code paths (when IsValid returns false). Normally you should initiate the result variable at the top of the function, like "Result := 0".

The good news is that with Pascal Analyzer, our popular static code analyzer product, these situations can be detected automatically. There is a section WARN18 in the Warnings Report. It is called "Function result not set".

Not so hard to spot! But imagine finding this problem among thousands of lines of code spread over hundreds of units! And consider also a code base that is evolving all the time, so the code must constantly be rechecked.

Pascal Analyzer currently has a total of 53 reports. Those are divided into over 230 sections, all providing statistics, references, errors and warnings for your code. Pascal Analyzer can be run as a standalone Windows application, or as a command-line program. The second choice is suitable if you want to integrate static code analysis with your build process.

Or use Pascal Expert, our RAD Studio plugin, to find the problems immediately while coding. Pascal Expert contains much of the same capabilities like Pascal Analyzer, and is obtainable with a discount when buying both products.

See our orders page for more details or get free evaluations from the download page.