do_block.ex

defmodule Test do
  defmacro foo_macro(bar, block) do
    IO.inspect bar
    IO.inspect block
  end

  def foo(bar, block) do
    IO.inspect bar
    IO.inspect block
  end

  defmacro puts(string) do
    IO.puts string
  end
end

defmodule Run do
  def run do
    require Test

    Test.puts "Macro with nums"
    Test.foo_macro(1,2)

    Test.puts "Macro with expr"
    _ = Test.foo_macro(1 + 1, 2 + 2)

    Test.puts "Macro with expr and do"
    Test.foo_macro(1 + 1) do
      2 + 2
    end

    Test.puts "macro with expr and explicit do keyword list"
    Test.foo_macro(1 + 1, [do: 2 + 2])

    IO.puts "function with nums"
    Test.foo(1,2)

    IO.puts "function with expr"
    Test.foo(1 + 1, 2 + 2)

    IO.puts "function with expr do"
    Test.foo(1 + 1) do
      2 + 2
    end

    IO.puts "function with expr and explicit do keyword list"
    Test.foo(1 + 1, [do: 2 + 2])
  end
end

Run.run

Output elixir do_block.ex:

Macro with nums
1
2
Macro with expr
{:+, [line: 25], [1, 1]}
{:+, [line: 25], [2, 2]}
Macro with expr and do
{:+, [line: 28], [1, 1]}
[do: {:+, [line: 29], [2, 2]}]
macro with expr and explicit do keyword list
{:+, [line: 33], [1, 1]}
[do: {:+, [line: 33], [2, 2]}]
function with nums
1
2
function with expr
2
4
function with expr do
2
[do: 4]
function with expr and explicit do keyword list
2
[do: 4]