# This module is only available on Linux. It provides a way to make direct system calls into the operating system.
# You most likely doesn't need this, unless you know what you are doing.
#
# For more details about Linux system calls, refer to
# [https://man7.org/linux/man-pages/man2/syscalls.2.html](https://man7.org/linux/man-pages/man2/syscalls.2.html).
#

@[Experimental]
module Syscall
  # To define system calls open a module and use the `def_syscall` macro. Pass in the system call name,
  # the return type and its arguments. For example:
  #
  # ```
  # module YourSyscalls
  #   Syscall.def_syscall pipe2, Int32, pipefd : Int32[2]*, flags : Int32
  #   Syscall.def_syscall write, Int32, fd : Int32, buf : UInt8*, count : LibC::SizeT
  #   Syscall.def_syscall read, Int32, fd : Int32, buf : UInt8*, count : LibC::SizeT
  #   Syscall.def_syscall close, Int32, fd : Int32
  # end
  # ```
  #
  # They can then be called as methods from the `Syscall` module:
  #
  # ```
  # YourSyscalls.write(1, "Hello!\n".to_unsafe, 7)
  # ```
  macro def_syscall(name, return_type, *args)
    {% raise "The Syscall module is not supported on this target. It's only available for Linux." %}
  end
end

require "./syscall/*"