Marlin_Firmware/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"

        def on_program_ready(source, target, env):
            import shutil
            shutil.copy(target[0].get_abspath(), env.subst("$PROJECT_BUILD_DIR/$PIOENV"))

        env.AddPostAction("$PROGPATH", on_program_ready)

    # 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()