Cppcheck architecture and writting my own rules in C++

[hardork]

Hello,
I am new on the cppcheck topic, and I am trying to understand how to write my own rules.
I have seen the addon part to write with python, but I would like to try the C++ part.
There is a link on the wiki on a documentation, but the link is broken : http://sourceforge.net/projects/cppcheck/files/Articles/writing-rules-3.pdf/download

Is there any documentation to help me start, some clue about the architecture, the tokens etc. ?

Thanks in advance and thank you for this tool!

[Daniel Marjamäki]

do you have some specific idea?

[hardork]

Well currently the first check I want to try to implement is pretty straightforward.
I want to report an error when a call to the strtok function is done.

[Daniel Marjamäki]

yes that rule sounds pretty easy to implement. I guess you can look at CheckFunctions::memsetZeroBytes().

[hardork]

Thank you for the entry point.
Is there an easiest way to know that the current token is a function call?
In the case of memsetZeroBytes I see that it test the name of the function and the number or arguments with numberOfArguments and if I look at the code of numberOfArguments I see that it test that the next token is a "("

I take a quick look at astutils but didn't manage to find another solution and don't see anything specifics in the ast dump file.
Just to be sure I am doing the more direct approach.

[Daniel Marjamäki]

in this case I would check if strtok is a library function:

if (Token::simpleMatch(tok, "strtok (") && mSettings->library.getFunction(tok))

[hardork]

It works like a charm, thank you.
Now I am trying to implement something harder.

The rules is : when you are calling a function named QueryInterface(arg1, arg2)
You should call arg2.Release() before the end the scope of arg2.

I try to do, based on code in checkfunctions.cpp :

for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
            if (Token::Match(tok, "QueryInterface") &&(numberOfArguments(tok) == 2))
            {
                const std::vector<const Token*>& arguments = getArguments(tok);
                if (WRONG_DATA(arguments.size() != 2U, tok))
                    continue;
                const Token* lastParamTok = arguments[1];

at my great surprise lastParamTok return '('
The code I am parsing is :
pBS->QueryInterface(mkBSIntf::ClassId(), (void**)&PtrToBSIntf);

Is there a method for me to get PtrToBSIntf instead of '(' ?
Am I suppose to move on the ast starting from the '(' to find the variable name?

[Daniel Marjamäki]

Am I suppose to move on the ast starting from the '(' to find the variable name?

Yes. I recommend that you use astOperand1 and astOperand2. As you might have figured out a cast is in cppcheck AST a unary operator with 1 operand.

[hardork]

Hello,
I have made some great progress on my customs errors.

I have a new question:
My check search method1 call, but there is multiple definition of method1 coming from various class.
So I need to find method1 from myClass

How I am supposed to find the inheritance of the token named method1 in the source that I am currently checking to test that it come from myClass?
I take a look at the function class but didn't find anything usefull

Thank you for you endless help Daniel!

[Daniel Marjamäki]

not sure. I think something like this:

Function::functionScope() => Scope::functionOf() => class scope

I assume that the class declaration is seen.