Enable -Wextra in CI builds #6814
Description
Related area
CI
Hardware specification
n/a
Is your feature request related to a problem?
As a follow-up to #6782 (comment), we should now add -Wextra when building the code in CI.
Describe the solution you'd like
- Option 1: something along the lines of Error even w/warnings disabled for no-return fcns esp8266/Arduino#8495 (move arguments into a file, use
@to tell GCC to read arguments from file) - Option 2: In a CI build, use sed to add -Wextra to the list of warning flags in platform.txt
Describe alternatives you've considered
No response
Additional context
No response
I have checked existing list of Feature requests and the Contribution Guide
- I confirm I have checked existing list of Feature requests and Contribution Guide.