-Wmissing-declarations enforces that every function (except for static
functions) must be declared separately before it's defined. This
essentially enforces that every function must be either static, or
declared in a header elsewhere.
This helps the optimizer, as it can do a better job of inlining if it
knows that a function won't be used outside of a given file. It also
helps -Wunused-function (which is enabled by -Wall) find more unused
functions.
Note that Clang spells this option -Wmissing-prototypes, which
confusingly is the name of a related but different warning option under
GCC.
Clang by default compiles with -Winconsistent-missing-override, which
warns when a class declares virtual functions that override those in the
base class, and some but not all of them are explicitly declared
`override`.
GCC doesn't support this option, but has a stronger version,
-Wsuggest-override. In combination with -Werror, this means that any
virtual function that overrides another *must* be explicitly declared as
`override`.
This commit enables -Wsuggest-override where available. This means that
GCC users can't break the Clang build with inconsistent overrides (see
#1113 and #1114) and consequently that any build that passes the pull
request CI build on Jenkins won't break because of inconsistent
overrides.
Currently the build fails because of -Wdelete-non-virtual-dtor warnings.
This catches when an object is destructed, has a non-virtual destructor,
and is an abstract base class or a non-final class with virtual
functions. The warning happens inside unique_ptr<T>::~unique_ptr.
The warning is to prevent somebody writing code like this:
class MySceneEndCondition : public CSceneEndCondition {
~MySceneEndCondition() { /* some complex logic */ }
};
// this won't call MySceneEndCondition's destructor, potentially
// leading to leaks or segfaults:
std::unique_ptr<CSceneEndCondition> p{new MySceneEndCondition()};
krzys_h
immibis