Definition of INADDR_NONE in header file bloats final executable size

[MHotchin]

Currently, IPADDRESS.H both declares and defines INADDR_NONE.

If a sketch has more than one file that includes IPAddress.h, then multiple copies of INADDR_NONE end up in the final executable. Essentially, each CPP file gets its own copy as a global variable, at 6 bytes a pop.

If the declaration in IPAddress.h is changed to:
extern const IPAddress INADDR_NONE;

and a new definition is provided in IPAddress.cpp:
const IPAddress INADDR_NONE(0, 0, 0, 0);

then only one copy end up in the executable.

My sketch went from 2002 bytes 'Minimum Memory Usage' to 1888 bytes, a savings of 78 bytes in my case.

[Rotzbua]

The ethernet library does not contain a IPAddress.h/.ccp .

It is part of the main arduino framework. I reported this years ago. It is fixed in the default arduino framework.

My last update was that the uno is not (yet?) migrated to the default arduino framework.

Best

[per1234]

Thanks for the explanation @Rotzbua.

Closing as duplicate of arduino/Arduino#1007, which was fixed by arduino/ArduinoCore-API@3dbd7d7 (but has not yet propagated out to all the core libraries).