defmacrop doesn't work without parenthesis after Elixir 1.15

[petrkozorezov]

Elixir and Erlang/OTP versions

Erlang/OTP 25 [erts-13.2.2.5] [source] [64-bit] [smp:16:16] [ds:16:16:10] [async-threads:1] [jit:ns]

Elixir 1.15.7 (compiled with Erlang/OTP 25)

Operating system

Linux asrock-x300 6.1.71 #1-NixOS SMP PREEMPT_DYNAMIC Fri Jan 5 14:18:41 UTC 2024 x86_64 GNU/Linux

Current behavior

Corrected example of private macros doesn't work in Elixir 1.15 (but works in 1.14)

iex(1)> defmodule Sample do
...(1)>  defmacrop two, do: 2
...(1)>  def four, do: two + two
...(1)> end
error: undefined variable "two"
  iex:9: Sample.four/0

error: undefined variable "two"
  iex:9: Sample.four/0

warning: macro two/0 is unused
  iex:8: Sample (module)

** (CompileError) iex: cannot compile module Sample (errors have been logged)
    (elixir 1.15.7) elixir_module.erl:182: anonymous fn/9 in :elixir_module.compile/7
    iex:7: (file)

But it works with parenthesis

iex(1)> defmodule Sample do
...(1)>  defmacrop two, do: 2
...(1)>  def four, do: two() + two()
...(1)> end

{:module, Sample,
 <<70, 79, 82, 49, 0, 0, 5, 124, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 169,
   0, 0, 0, 17, 13, 69, 108, 105, 120, 105, 114, 46, 83, 97, 109, 112, 108, 101,
   8, 95, 95, 105, 110, 102, 111, 95, 95, ...>>, {:four, 0}}
iex(2)> Sample.four
4

Expected behavior

Private macro without parenthesis should work.

[josevalim]

I will fix the documentation. There is a flag to enable the old behaviour, if desired: see :on_undefined_variable. I will fix the example.