[BUG] warnings building SoftwareSerial example

[henrygab]

Describe the bug
Sample code currently emits warnings.

.../SoftwareSerial/SoftwareSerial.cpp:222:6:
    warning: always_inline function might not be inlinable [-Wattributes]

 void SoftwareSerial::recv()
      ^~~~~~~~~~~~~~

Set up (please complete the following information)

• Using code from PR 376

To Reproduce
Steps to reproduce the behavior:

1. Start a build based on PR 376
2. Allow the build to complete
3. Expand one of the three build jobs that enable additional warnings
4. Review the build logs
   for the sample being fixed.

Expected behavior
Sample code should build without warnings.

[henrygab]

OK … I'll admit I'm not entirely sure how I'd remove this warning.

[hathach]

I am happy to say that this issue is addressed, the recv() is declared as inline but in fact gcc cannot make it inline and have to emit the actual function. I have fixed this recent release, I am glad to say that we are finally building with --all warnings flags in ci https://github.com/adafruit/Adafruit_nRF52_Arduino/blob/master/tools/build_all.py#L62 . Other Adafruit core and libraries also compile with all in CI now, And you are the big reason to push that. Thank you very much 💯 💯

[henrygab]

Thank you! I know you've been extremely busy, and I appreciate the work that went into enabling --warnings all. :)