void Connect3ArgLambda::VisitStmt()

in src/checks/level1/connect-3arg-lambda.cpp [31:124]
74 lines of code
23 McCabe index (conditional complexity)

void Connect3ArgLambda::VisitStmt(clang::Stmt *stmt)
{
    auto *callExpr = dyn_cast<CallExpr>(stmt);
    if (!callExpr) {
        return;
    }

    FunctionDecl *fdecl = callExpr->getDirectCallee();
    if (!fdecl) {
        return;
    }

    const uint numParams = fdecl->getNumParams();
    if (numParams != 2 && numParams != 3) {
        return;
    }

    std::string qualifiedName = fdecl->getQualifiedNameAsString();
    if (qualifiedName == "QTimer::singleShot") {
        processQTimer(fdecl, stmt);
        return;
    }

    if (qualifiedName == "QMenu::addAction") {
        processQMenu(fdecl, stmt);
        return;
    }
    if (qualifiedName == "QWidget::addAction") {
        processWidget(fdecl, stmt);
        return;
    }

    if (numParams != 3 || !clazy::isConnect(fdecl)) {
        return;
    }

    auto *arg3 = callExpr->getArg(2);
    auto *lambda = clang::dyn_cast_or_null<LambdaExpr>(arg3);
    if (!lambda) {
        lambda = clazy::getFirstChildOfType2<LambdaExpr>(arg3);
        if (!lambda) {
            return;
        }
    }

    DeclRefExpr *senderDeclRef = nullptr;
    const MemberExpr *senderMemberExpr = nullptr;

    Stmt *s = callExpr->getArg(0);
    while (s) {
        if ((senderDeclRef = dyn_cast<DeclRefExpr>(s))) {
            break;
        }

        if ((senderMemberExpr = dyn_cast<MemberExpr>(s))) {
            break;
        }

        s = clazy::getFirstChild(s);
    }

    // The sender can be: this
    const auto *senderThis = clazy::unpeal<CXXThisExpr>(callExpr->getArg(0), clazy::IgnoreImplicitCasts);

    // The variables used inside the lambda
    auto declrefs = clazy::getStatements<DeclRefExpr>(lambda->getBody());

    const ValueDecl *senderDecl = senderDeclRef ? senderDeclRef->getDecl() : nullptr;

    // We'll only warn if the lambda is dereferencing another QObject (besides the sender)
    bool found = false;
    for (auto *declref : declrefs) {
        ValueDecl *decl = declref->getDecl();
        if (decl == senderDecl) {
            continue; // It's the sender, continue.
        }

        if (clazy::isQObject(decl->getType())) {
            found = true;
            break;
        }
    }

    if (!found) {
        auto thisexprs = clazy::getStatements<CXXThisExpr>(lambda->getBody());
        if (!thisexprs.empty() && !senderThis) {
            found = true;
        }
    }

    if (found) {
        emitWarning(stmt, "Pass a context object as 3rd connect parameter");
    }
}