Question

I have an empty project (it contains just a form). If I add this line to the project ‘USES GR32_Image;’ and run the application, FastMM shows leak in the program. FastMM is set to full debug. There is NO code in my program – except what Delphi IDE generates and except the ‘uses gr32’ line.

The report makes no sense.
Here is the full log: http://pastebin.com/Yhev3rJ2
And here is the source code: http://pastebin.com/VjRrRiS8

I have used the Graphics32 unit before and I never had problems. Why I have this leak and why FastMM cannot generate a proper report?

Answer 1

Compile your app with full debug info, then in the linker options, make sure your debug info is in the .EXE and/or .MAP file.

Then run FastMM with FullDebugMode, and copy/paste the resulting .TXT file in your question.

See also this post for more tips.

Edit:

A good first step is to do something like this on your .TXT file:

find "The allocation number is" < fastmmlog.txt | sort /R

That gives you the first allocation number, in your case 281.

From that, you search in the .TXT for the allocation number:

--------------------------------2011/1/7 23:31:03--------------------------------
A memory block has been leaked. The size is: 20

This block was allocated by thread 0x1540, and the stack trace (return addresses) at the time was:
402D80 [System][System][@GetMem]
40388F [System][System][TObject.NewInstance]
403C12 [System][System][@ClassCreate]
4038C4 [System][System][TObject.Create]
403C12 [System][System][@ClassCreate]
403C6A [System][System][@AfterConstruction]
457922 [GR32_Bindings][GR32_Bindings][NewRegistry]
45807E [GR32_LowLevel][GR32_LowLevel][RegisterBindings]
458152 [GR32_LowLevel][GR32_LowLevel][GR32_LowLevel]
404373 [System][System][InitUnits]
4043DB [System][System][@StartExe]

The block is currently used for an object of class: TList

The allocation number is: 281

Here you can see, that the NewRegistry is involved in your leak.
From there, you can start debugging to find out why it leaks.

–jeroen