Source: https://gn.googlesource.com/gn/+/main/docs/cross_compiles.md

# Source: https://gn.googlesource.com/gn/+/main/docs/cross_compiles.md

declare_args() {
  # Applies only to toolchains targeting target_cpu.
  sysroot = ""
}

config("my_config") {
  # Uses current_cpu because compile flags are toolchain-dependent.
  if (current_cpu == "arm") {
    defines = ["CPU_IS_32_BIT"]
  } else {
    defines = ["CPU_IS_64_BIT"]
  }
  # Compares current_cpu with target_cpu to see whether current_toolchain
  # has the same architecture as target_toolchain.
  if (sysroot != "" && current_cpu == target_cpu) {
    cflags = [
      "-isysroot",
      sysroot,
    ]
  }
}