Why does this give a resourceLeak error?

[Sander Bouwhuis]

Why does the following code produce a resourceLeak error for hTileFont?
I allocate memory with CreateFont() and deallocate with DeleteObject().

~~~~~~
HFONT hTileFont = NULL;

// ...

hTileFont = CreateFont(i32TileFontHeight, 0, 0, 0, i32TileFontWeight, false, false, false, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, PROOF_QUALITY, VARIABLE_PITCH | FF_DONTCARE, pwcFontFace);

// ...

// Create the tiles
InitializeTile(&m_btnAccessControlAccessControl, MODULE_ACCESSCONTROL, L"Access_control", pwcIniFile, true, hTileFont, bTileBorder);

// ...

// Free the resources
if(hTileFont)
DeleteObject(hTileFont);

[Daniel Marjamäki]

sounds like a bug. but I fail to reproduce. I use this command:

$ ./cppcheck --platform=win32A --enable=style 1.c

Tried with this code:

void f() {
    HFONT hTileFont = NULL;
    hTileFont = CreateFont(i32TileFontHeight, 0, 0, 0, i32TileFontWeight, false, false, false, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, PROOF_QUALITY, VARIABLE_PITCH | FF_DONTCARE, pwcFontFace);
    InitializeTile(&m_btnAccessControlAccessControl, MODULE_ACCESSCONTROL, L"Access_control", pwcIniFile, true, hTileFont, bTileBorder);
    if(hTileFont)
        DeleteObject(hTileFont);
}

[Sander Bouwhuis]

I have it on a lot of places in my source code. Every time it thinks there is a resource leak. I don't understand why.

I use the GUI on Windows. Maybe that makes a difference?

[Daniel Marjamäki]

It is probably some detail there in your code that makes Cppcheck confused.

If you copy paste a function with FP to a different file and check that.. does it show the warning still? If it does then it's some detail in the function. Otherwise it seems there is something about a function call or type etc.

I would like that you reduce your code by repeating these steps:
1. remove some code
2. run cppcheck on the file
3. if the FP is not shown => undo changes

Start with large chunks of code. I often start by removing #includes. then I remove large blocks of code such as types/functions/etc.. when I do this, I remove stuff until every statement, every identifier and every operation etc is needed to reproduce the FP.

[Daniel Marjamäki]

I use the GUI on Windows. Maybe that makes a difference?

It should not make a difference.

Can you try to reproduce a FP with the command line cppcheck also? Try some command such as:

cppcheck --platform=win64 --library=windows <filename>

[Sander Bouwhuis]

Ooooooooooooooooh, shoot! I understand now.

The problem is that there is a return in the function when an error occurs. It should never happen, but if it occurs then I return out of the function. The hTileFont won't be deallocated then (actually, the application shuts down when this function fails so nothing matters then anymore).

Thanks for the help.