clang-tidy and clazy messages

[letsfindaway]

Analyzing the source code with clang-tidy and clazy gets a large amount of messages:

I would like to fix at least those which are potential errors, but also as much as possible from others. My categories are, in descending order of importance:

• FIXME Should definitely be fixed.
• TODO Probably no errors, but should be changed.
• CHECK Check for possible consequences. What have been the original intentions for that?
• NOTE Performance and code improvements.

Here the categorized list of messages together with a short explanation:

• [x] FIXME clang-analyzer-core.CallAndMessage Potential nullptr dereference.
• [x] FIXME clang-analyzer-core.uninitialized.Branch Branch condition evaluates to a garbage value.
• [x] FIXME clang-analyzer-core.uninitialized.UndefReturn Undefined or garbage value returned to caller.
• [x] FIXME clang-analyzer-cplusplus.NewDelete Use of memory after it is freed.
• [x] FIXME clang-analyzer-cplusplus.NewDeleteLeaks Potential leak of memory.
• [ ] CHECK clang-analyzer-deadcode.DeadStores Value stored to 'xxx' during its initialization is never read.
• [ ] TODO clang-analyzer-optin.cplusplus.VirtualCall Call to virtual method during construction bypasses virtual dispatch.
• [ ] NOTE clang-analyzer-security.FloatLoopCounter Variable with floating point type should not be used as a loop counter.
• [ ] NOTE: clazy-connect-not-normalized Signature is not normalized.
• [ ] TODO: clazy-const-signal-or-slot getter possibly mismarked as a slot.
• [ ] NOTE: clazy-container-anti-pattern allocating an unneeded temporary container. False positives
• [ ] TODO: clazy-detaching-temporary Don't call QList::first() on temporary.
• [ ] NOTE: clazy-fully-qualified-moc-types slot arguments need to be fully-qualified. Not relevant
• [x] FIXME: clazy-incorrect-emit Emitting inside constructor probably has no effect.
• [ ] NOTE: clazy-non-pod-global-static non-POD static. Not a problem for applications (not libraries)
• [ ] CHECK clazy-overloaded-signal signal is overloaded. Overloaded signals requires annoying casts during connects, which are not very elegant. This is more an architectural issue and not only a naming issue. Requires redesign. Postponed.
• [ ] TODO: clazy-overridden-signal Overriding signal with non-signal.
• [ ] NOTE: clazy-qcolor-from-literal The QColor ctor taking ints is cheaper than the one taking string literals.
• [ ] NOTE: clazy-qfileinfo-exists Use the static QFileInfo::exists() instead. It's documented to be faster.
• [ ] TODO: clazy-qproperty-without-notify Q_PROPERTY should have either NOTIFY or CONSTANT.
• [ ] NOTE: clazy-qstring-arg Use multi-arg instead.
• [ ] NOTE: clazy-qstring-insensitive-allocation unneeded allocation.
• [ ] DONT: clazy-qstring-ref Use rightRef() instead. This is not recommended with Qt 6!!!
• [ ] TODO: clazy-range-loop-detach c++11 range-loop might detach Qt container.
• [ ] TODO: clazy-range-loop-reference Missing reference in range-for with non trivial type.
• [ ] CHECK: clazy-rule-of-two-soft Using assign operator but class has copy-ctor but no assign operator.
• [ ] CHECK: clazy-unused-non-trivial-variable unused non-trivial variable.
• [ ] TODO: clazy-writing-to-temporary Call to temporary is a no-op: QPoint::setX.

[letsfindaway]

I will probably separate this into several PRs according to urgency. So the first PR will only contain the FIXME items.