Peganza - Blog

Can you find this Delphi coding error (part 14)?

February 10, 2025

Can you spot the error in the following Delphi code extract? Well, actually it is more of a potential problem, than an error, but anyway..

..
procedure CalculateResult;
var
  L : TList;
begin
  L := TList.Create;
  // .. more code here
  L.Free;
end;
..

This was quite easy, right?

Solution: The object L has an unprotected call to Free. You should use a try-finally block, to make sure that the object always will be freed. If it is not freed, the result is a memory leak.

The good news is that with Pascal Analyzer, our popular static code analyzer product, these situations can be detected automatically. There is a section MEMO1 in the Memory Report. It is called "Local objects with unprotected calls to Free".

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.