#248 Resolve compile-time warnings

[Ognyan Chernokozhev]

When warnings level is set to high, both C++ Builder and Visual C++ compile OWLNext with a lot of warnings.

We should clean as much as possible of these, as they can have adverse effect on compilation speed in user code that includes a lot of OWLNext headers.

Also reducing the number of warnings in OWLNext headers will make it easier to catch issues pointed by warnings in user code.

See discussion https://sourceforge.net/p/owlnext/discussion/97175/thread/e62de7e00c/

[Ognyan Chernokozhev]

Enabling warnings pointed to a small bug in TMenuGuard::RelinquishOwnership returning wrong value.

Fixed in trunk: [r6994].
Merged in 7.0 branch: [r7001].

[Ognyan Chernokozhev]

Eliminated a number of Level 4 warnings reported by Visual C++.

trunk: [r6995].
7.0: [r7002], fixed some regressions in [r7003].

[Ognyan Chernokozhev]

Replaced usages of NULL with nullptr.

trunk: [r6996].
7.0: [r7004].

[Ognyan Chernokozhev]

Eliminated warnings reported by C++Builder about using 0 instead of nullptr.

trunk: [r6997].
7.0: [r7005].

[Ognyan Chernokozhev]

Fixed some "old C-style cast" warnings reported by C++ Builder.

trunk: [r7006], [r7009], [r7011], [r7012].
7.0: [r7013], [r7014], [r7015], [r7016]. Fixed post-merge errors in [r7015].

[Ognyan Chernokozhev]

Eliminated many "0 as nullptr" warnings.

trunk: [r7019].
7.0: [r7020].

[Ognyan Chernokozhev]

Fixed an 'unused parameter' warning in dc.h.

trunk: [r7021].
Note: New code that is not present in 7.0.

[Ognyan Chernokozhev]

Fixed an 'unused parameter' warning in dispatch.h.

trunk: [r7022].
7.0: [r7023].

[Ognyan Chernokozhev]

Removed the __OWL_OWLDEFS_H macro.
This macro according to a comment was only for VbxGen compatibility, and this is a tool no longer used.

trunk: [r7024].
7.0: [r7025].

[Ognyan Chernokozhev]

Added macros for disabling compiler warnings.

trunk: [r7026], [r7038], [r7049].
7.0: [r7037], [r7039], [r7050].

[Ognyan Chernokozhev]

Disabled "extension" warnings in number.h.

trunk: [r7027].
7.0: [r7033].

[Ognyan Chernokozhev]

Removed obsolete unused macros.

_DOCVIEWCLASS and _DOCVIEWENTRYare no longer used.

_DOCVIEWCLASS was used in OWL5 for TOleLinkView, but that class has been moved to OCFNext.

_DOCVIEWENTRY was used for TDocTemplateT only in 16-bit builds which are no longer supported.

trunk: [r7028].
7.0: [r7034].

[Ognyan Chernokozhev]

Removed unused obsolete macro _RTTI.

It may have been needed for old non-standard-compliant compilers like BC++ 5.02.

trunk: [r7029].

Note: Used in some more places in 7.0, will require separate code change to remove.

[Ognyan Chernokozhev]

Removed extra semicolons.

trunk: [r7030].

Note: Some of the places are in new code in trunk, may require separate code change to resolve in 7.0.

[Ognyan Chernokozhev]

Eliminated 'macro not defined, evaluates to 0' warnings.

trunk: [r7031].
7.0: [r7035].

[Ognyan Chernokozhev]

Added override to destructors.

trunk: [r7032].
7.0: [r7036].

[Ognyan Chernokozhev]

Removed obsolete check for checks.h.

Another legacy of BC++ 5.02 where there was a separate non-OWL header checks.h.

trunk: [r7040].
7.0: [r7044].

[Ognyan Chernokozhev]

Renamed the sentry macro for picker.h.

trunk: [r7041].
7.0: [r7045].

[Ognyan Chernokozhev]

Suppressed "zero is a null pointer constant" warnings in window.h and dispatch.h.

The warnings were given for the usage of HWND_DESKTOP and HANDLE_WM_NCACTIVATE, which are defined in SDK headers and cannot be changed.

trunk: [r7042].
7.0: [r7046].

[Ognyan Chernokozhev]

Fixed some "zero is a null pointer constant" warnings.

trunk: [r7043].
7.0: [r7047].

[Ognyan Chernokozhev]

Eliminated some "'const' type qualifier on return type has no effect" warnings. See [feature-requests:#248].

trunk: [r7051].
7.0: [r7052].

[Ognyan Chernokozhev]

A number of member methods of TSysLink are defined like this:

  auto GetIdealHeight() -> int const;

This looks like a mistake - shouldn't it be

  auto GetIdealHeight() const -> int;

Fixed in trunk in [r7053].

Note: the change may be binary incompatible, so for the moment will not be merged into the 7.0 branch.

[Vidar Hasfjord]

@jogybl wrote:

This looks like a mistake [in TSysLink methods]

Yes, this is a bug of mine. Cool that your work on eliminating warnings identified it. I should have turned on all warnings when writing that class.

Good work!

[Ognyan Chernokozhev]

Some methods in TFile and TTextFile are defined like this:

virtual void _OWLENTRY writeUint8( const uint8 )
virtual void _OWLENTRY writeUint16( const uint16 );

The const modifier of the parameter makes no sense - we should remove it.

Since the method is virtual, there is a small chance it may break user code if it is deriving from either class and overriding these methods.

The change should be made only in trunk, as it can also break binary compatibility of the dlls.

[Ognyan Chernokozhev]

Eliminated some old-style C cast warnings.

trunk: [r7054].
7.0: [r7055].