Handle escaped assignee from macroexpand output

[fonsp]

Something changed in macroexpand in Julia 1.12. The result now includes lots of Expr(Symbol("hygienic-scope") and Expr(:escape, and ExpressionExplorer needs to handle this correctly.

Change in macroexpand output

Julia 1.10:

julia> @macroexpand @enum Fruit 🍎 🍐
:($(Expr(:toplevel, :(#= Enums.jl:210 =#), quote
    $(Expr(:meta, :doc))
    primitive type Fruit <: Base.Enums.Enum{Int32} 32 end
end, :(#= Enums.jl:211 =#), :(function Fruit(var"#6#x"::Base.Enums.Integer)
      #= Enums.jl:211 =#
      #= Enums.jl:212 =#
      (0 Base.Enums.:<= var"#6#x" Base.Enums.:<= 1) || Base.Enums.enum_argument_error(:Fruit, var"#6#x")
      #= Enums.jl:213 =#
      return Base.Enums.bitcast(Fruit, Base.Enums.convert(Int32, var"#6#x"))
  end), :(#= Enums.jl:215 =#), :((Base.Enums.Enums).namemap(::Base.Enums.Type{Fruit}) = begin
          #= Enums.jl:215 =#
          Dict{Int32, Symbol}(0 => :🍎, 1 => :🍐)
      end), :(#= Enums.jl:216 =#), :((Base.Enums.Base).typemin(var"#8#x"::Base.Enums.Type{Fruit}) = begin
          #= Enums.jl:216 =#
          Fruit(0)
      end), :(#= Enums.jl:217 =#), :((Base.Enums.Base).typemax(var"#9#x"::Base.Enums.Type{Fruit}) = begin
          #= Enums.jl:217 =#
          Fruit(1)
      end), :(#= Enums.jl:218 =#), :(let var"#3#type_hash" = Base.Enums.hash(Fruit)
      #= Enums.jl:223 =#
      (Base.Enums.Enums)._enum_hash(var"#11#x"::Fruit, var"#12#h"::Base.Enums.UInt) = begin
              #= Enums.jl:223 =#
              Base.Enums.hash(var"#3#type_hash", Base.Enums.hash(Base.Enums.Integer(var"#11#x"), var"#12#h"))
          end
  end), :(#= Enums.jl:225 =#), :(let var"#4#insts" = (Base.Enums.Any[Fruit(var"#5#v") for var"#5#v" = Int32[0, 1]]...,)
      #= Enums.jl:226 =#
      (Base.Enums.Base).instances(::Base.Enums.Type{Fruit}) = begin
              #= Enums.jl:226 =#
              var"#4#insts"
          end
  end), :(const 🍎 = Fruit(0)), :(const 🍐 = Fruit(1)), :(Base.Enums.nothing))))

Julia 1.12

julia%                                                                          ➜  ~ julia +1.12
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.12.0-beta1 (2025-04-02)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org release
|__/                   |

julia> @macroexpand @enum Fruit 🍎 🍐
:($(Expr(:toplevel, :(#= Enums.jl:210 =#), :($(Expr(Symbol("hygienic-scope"), :(#= Enums.jl:210 =# Base.@__doc__ primitive type $(Expr(:escape, :Fruit)) <: Enum{Int32} 32 end), Base.Enums, :(#= REPL[1]:1 =#)))), :(#= Enums.jl:211 =#), :($(Expr(Symbol("hygienic-scope"), :(function ($(Expr(:escape, :Fruit)))(x::Integer)
      #= Enums.jl:211 =#
      #= Enums.jl:212 =#
      0 <= x <= 1 || enum_argument_error(:Fruit, x)
      #= Enums.jl:213 =#
      return bitcast($(Expr(:escape, :Fruit)), convert(Int32, x))
  end), Base.Enums, :(#= REPL[1]:1 =#)))), :(#= Enums.jl:215 =#), :($(Expr(Symbol("hygienic-scope"), :(Enums.namemap(::Type{$(Expr(:escape, :Fruit))}) = begin
          #= Enums.jl:215 =#
          $(Expr(:escape, Dict{Int32, Symbol}(0 => :🍎, 1 => :🍐)))
      end), Base.Enums, :(#= REPL[1]:1 =#)))), :(#= Enums.jl:216 =#), :($(Expr(Symbol("hygienic-scope"), :(Base.typemin(x::Type{$(Expr(:escape, :Fruit))}) = begin
          #= Enums.jl:216 =#
          ($(Expr(:escape, :Fruit)))(0)
      end), Base.Enums, :(#= REPL[1]:1 =#)))), :(#= Enums.jl:217 =#), :($(Expr(Symbol("hygienic-scope"), :(Base.typemax(x::Type{$(Expr(:escape, :Fruit))}) = begin
          #= Enums.jl:217 =#
          ($(Expr(:escape, :Fruit)))(1)
      end), Base.Enums, :(#= REPL[1]:1 =#)))), :(#= Enums.jl:218 =#), :($(Expr(Symbol("hygienic-scope"), :(let type_hash = hash($(Expr(:escape, :Fruit)))
      #= Enums.jl:223 =#
      Enums._enum_hash(x::$(Expr(:escape, :Fruit)), h::UInt) = begin
              #= Enums.jl:223 =#
              hash(type_hash, hash(Integer(x), h))
          end
  end), Base.Enums, :(#= REPL[1]:1 =#)))), :(#= Enums.jl:225 =#), :($(Expr(Symbol("hygienic-scope"), :(let insts = (Any[($(Expr(:escape, :Fruit)))(v) for v = Int32[0, 1]]...,)
      #= Enums.jl:226 =#
      Base.instances(::Type{$(Expr(:escape, :Fruit))}) = begin
              #= Enums.jl:226 =#
              insts
          end
  end), Base.Enums, :(#= REPL[1]:1 =#)))), :($(Expr(Symbol("hygienic-scope"), :(const $(Expr(:escape, :🍎)) = ($(Expr(:escape, :Fruit)))(0)), Base.Enums, :(#= REPL[1]:1 =#)))), :($(Expr(Symbol("hygienic-scope"), :(const $(Expr(:escape, :🍐)) = ($(Expr(:escape, :Fruit)))(1)), Base.Enums, :(#= REPL[1]:1 =#)))), :($(Expr(Symbol("hygienic-scope"), :nothing, Base.Enums, :(#= REPL[1]:1 =#)))))))

The solution is to simply ignore the :escape in expressions like :(Expr(:escape, :asdf) = 123). We could track whether we are inside hygienic-scope, but I don't escape-without-hygienicscope is an important edge case to take into account.

[fonsp]

I also asked the Julia community if this change was intentional: JuliaLang/julia#58225