marlin/buildroot/share/PlatformIO/scripts/common-cxxflags.py

#
# common-cxxflags.py
# Convenience script to apply customizations to CPP flags
#
import pioutil
if pioutil.is_pio_build():
	Import("env")

	cxxflags = [
		#"-Wno-incompatible-pointer-types",
		#"-Wno-unused-const-variable",
		#"-Wno-maybe-uninitialized",
		#"-Wno-sign-compare"
	]
	if "teensy" not in env['PIOENV']:
		cxxflags += ["-Wno-register"]
	env.Append(CXXFLAGS=cxxflags)

	#
	# Add CPU frequency as a compile time constant instead of a runtime variable
	#
	def add_cpu_freq():
		if 'BOARD_F_CPU' in env:
			env['BUILD_FLAGS'].append('-DBOARD_F_CPU=' + env['BOARD_F_CPU'])

	# Useful for JTAG debugging
	#
	# It will separate release and debug build folders.
	# It useful to keep two live versions: a debug version for debugging and another for
	# release, for flashing when upload is not done automatically by jlink/stlink.
	# Without this, PIO needs to recompile everything twice for any small change.
	if env.GetBuildType() == "debug" and env.get('UPLOAD_PROTOCOL') not in ['jlink', 'stlink', 'custom']:
		env['BUILD_DIR'] = '$PROJECT_BUILD_DIR/$PIOENV/debug'

	# On some platform, F_CPU is a runtime variable. Since it's used to convert from ns
	# to CPU cycles, this adds overhead preventing small delay (in the order of less than
	# 30 cycles) to be generated correctly. By using a compile time constant instead
	# the compiler will perform the computation and this overhead will be avoided
	add_cpu_freq()