B4R Question ArduinoBLE lib wrapping EMPTY issue

[rwblinn]

Hi,

working to wrap the ArduinoBLE library to be used with an Arduino GIGA R1.

Getting this error when compiling a test sketch:

Basic\B4R\Objects\src\rCore.h:614:40: error: expected unqualified-id before ';' token 614 | static B4RString* EMPTY; | ^ In file included from C:...

I confirmed the issue is caused by a macro named EMPTY coming from the Arduino GIGA (mbed / Zephyr / CMSIS) core.
Undefining EMPTY in B4RDefines.h is not sufficient, because the macro is reintroduced per translation unit by the Arduino core.

The only robust fix is to undefine EMPTY locally in rCore.h:

// --- Fix macro collision with Zephyr / mbed ---
#ifdef EMPTY
  #undef EMPTY
#endif
static B4RString* EMPTY;

This keeps API compatibility and avoids renaming core symbols.

Another option would be to rename EMPTY to EMPTYSTR in rCore.h and rCore.cpp:

static B4RString* EMPTYSTR;

static B4RString be_empty;
B4RString* B4RString::EMPTYSTR = be_empty.wrap("");

Is there another solution for this instead modifying the B4R rCore?

 

[Erel]

Another option would be to rename EMPTY to EMPTYSTR in rCore.h and rCore.cpp:

This will not work without updating B4R as the compiler emits code referencing this variable. I will change this variable name in the next update. For now you will need to modify rCore.h.

 

[Peter Simpson]

Hello @rwblinn,
I presume that you're creating another excellent library for the community.

I do have a B4R wrap of the ArduinoBLE library I obviously called it rArduinoBLE, if you would be willing to test it for me. I remember wrapping the Peripheral code, I may or may not have wrapped in the Central code. I wrapped this library when I was updating Erel's original the B4A BLE Peripheral library. I think it's working fully, but I didn't really test it that much as what I needed was for Android production hardware and not Arduino/ESP, so I just left it, well until I saw your post, then I quickly tested this.

ESP32 Peripheral - Android screenshot below:

Let me know, and I'll PM you the code...

 

[rwblinn]

Thanks Peter.
In the meantime have created first version of 2 libraries rArduinoBLECentral & Peripheral.
Tested and working OK.
Happy to test yours.
See my PM.