Failure to create return vars

[timholy]

While working on updating the docs, I came across something really weird:

julia> using JuliaInterpreter

julia> @breakpoint sum([1, 2]) any(x->x>4, a)
breakpoint(sum(a::AbstractArray) in Base at reducedim.jl:648, line 648)

julia> val = @interpret sum([1,2,3])
6

julia> val
6

julia> frame, bp = @interpret sum([1,2,5])
(Frame for sum(a::AbstractArray) in Base at reducedim.jl:648
c 1 648  1 ─      nothing
  2 648  │   %2 = (Base.#sum#550)(Colon(), #self#, a)
  3 648  └──      return %2
a = [1, 2, 5], breakpoint(sum(a::AbstractArray) in Base at reducedim.jl:648, line 648))

julia> frame
ERROR: UndefVarError: frame not defined

julia> bp
ERROR: UndefVarError: bp not defined

julia> x, y = begin
           (1, 2)
       end
(1, 2)

julia> x
1

julia> y
2

julia> macroexpand(Main, :(frame, bp = @interpret sum([1, 2])))
:((frame, bp = begin
              #= /home/tim/.julia/dev/JuliaInterpreter/src/construct.jl:633 =#
              #11#theargs = (sum, a)
              #= /home/tim/.julia/dev/JuliaInterpreter/src/construct.jl:634 =#
              #12#frame = (JuliaInterpreter.JuliaInterpreter).enter_call_expr((JuliaInterpreter.Expr)(:call, #11#theargs...))
              #= /home/tim/.julia/dev/JuliaInterpreter/src/construct.jl:635 =#
              if #12#frame === JuliaInterpreter.nothing
                  #= /home/tim/.julia/dev/JuliaInterpreter/src/construct.jl:636 =#
                  return (JuliaInterpreter.eval)((JuliaInterpreter.Expr)(:call, (JuliaInterpreter.map)(JuliaInterpreter.QuoteNode, #11#theargs)...))
              end
              #= /home/tim/.julia/dev/JuliaInterpreter/src/construct.jl:638 =#
              if (JuliaInterpreter.shouldbreak)(#12#frame, 1)
                  #= /home/tim/.julia/dev/JuliaInterpreter/src/construct.jl:639 =#
                  return (#12#frame, (JuliaInterpreter.BreakpointRef)((#12#frame).framecode, 1))
              end
              #= /home/tim/.julia/dev/JuliaInterpreter/src/construct.jl:641 =#
              #13#ret = (JuliaInterpreter.finish_and_return!)(#12#frame)
              #= /home/tim/.julia/dev/JuliaInterpreter/src/construct.jl:642 =#
              if #13#ret isa JuliaInterpreter.BreakpointRef
                  (#12#frame, #13#ret)
              else
                  #13#ret
              end
          end))

julia> 

If you access ans then you can get both frame and bp, but collecting them by ordinary means seems not to work. Do you understand this at all?

[KristofferC]

Yes, it is the return statement in the macro

julia> a, b = return 1, 2
(1, 2)

julia> a
ERROR: UndefVarError: a not defined

julia> b
ERROR: UndefVarError: b not defined

julia> ans
(1, 2)