Function patch_platformio_ini

tests/measure_esp32s3_opt_ins.py:182–223

Inject cfg's build_flags / overlay into the [env:esp32s3] block. This is a targeted regex patch — we don't fully re-parse INI because PlatformIO's flavor of INI carries continuation lines and `${var.x}` interpolations that configparser mangles. The regex target is the literal `[env:

(cfg: OptInConfig)

def patch_platformio_ini(cfg: OptInConfig) -> None:
    """Inject cfg's build_flags / overlay into the [env:esp32s3] block.

    This is a targeted regex patch — we don't fully re-parse INI
    because PlatformIO's flavor of INI carries continuation lines and
    `${var.x}` interpolations that configparser mangles. The regex
    target is the literal `[env:esp32s3]` header through the next
    `[env:` header (or EOF), which is well-defined in practice.
    """
    text = PLATFORMIO_INI.read_text(encoding="utf-8")
    block_re = re.compile(r"(\[env:esp32s3\][^\[]*?)(?=\n\[env:|\Z)", re.DOTALL)
    match = block_re.search(text)
    if not match:
        print(
            "measure-opt-ins: could not locate [env:esp32s3] block in platformio.ini",
            file=sys.stderr,
        )
        sys.exit(2)
    block = match.group(1)
    if cfg.build_flags:
        extra = "\n    " + "\n    ".join(cfg.build_flags)
        if "build_flags =" in block:
            block = re.sub(
                r"(build_flags\s*=)",
                r"\1" + extra,
                block,
                count=1,
            )
        else:
            block = block.rstrip() + "\nbuild_flags =" + extra + "\n"
    if cfg.overlay:
        line = f"board_build.sdkconfig_defaults = {OVERLAY_PATH}\n"
        if "board_build.sdkconfig_defaults" in block:
            block = re.sub(
                r"board_build\.sdkconfig_defaults\s*=.*",
                line.rstrip(),
                block,
            )
        else:
            block = block.rstrip() + "\n" + line
    new_text = text[: match.start()] + block + text[match.end() :]
    PLATFORMIO_INI.write_text(new_text, encoding="utf-8")


def _run_compile_cmd(example: str) -> list[str]: