Optimize (-O -O1 -O2...) with PlatformIO

[LazaroFilm]

I can't find the optimization option in PlatformIO. I see it in Arduino IDE's menu but I can't find where it would be in VS Code's PlatformIO...

[maxgerhardt]

PlatformIO applies a default optimization of -Os. As documented in build_flags and build_unflags, you can throw the default one out and insert your own in the platformio.ini like so:

; throw out default optimize for size
build_unflags = -Os
; let's make this slow on purpose because why not ^_^
build_flags = -O0

You can always verify that your wanted flags are applied by looking at the full compiler invocations as shown in project tasks -> Advanced -> Verbose Build.