minimal_transform.jl

# Recursively wraps function calls with the below generated function call and inserts the context argument.
function remix!(ir, hooks = false)
    pr = IRTools.Pipe(ir)
    new = argument!(pr)
    for (v, st) in pr
        ex = st.expr
        ex isa Expr && ex.head == :call && begin
            if !(ex.args[1] isa GlobalRef && (ex.args[1].mod == Base || ex.args[1].mod == Core))
                args = copy(ex.args)
                ex = Expr(:call, :remix!, new, ex.args...)
                pr[v] = ex
                if hooks
                    insert!(pr, v, Expr(:call, :scrub!, new, args...))
                    insertafter!(pr, v, Expr(:call, :dub!, new, args...))
                end
            end
        end
    end
    ir = IRTools.finish(pr)

    # Swap.
    ir_args = IRTools.arguments(ir)
    insert!(ir_args, 2, ir_args[end])
    pop!(ir_args)
    argument!(ir)
    insert!(ir_args, 3, ir_args[end])
    ir = IRTools.renumber(ir)
    ir
end

@generated function remix!(ctx::MixTable, fn::Function, args...)
    T = Tuple{fn, args...}
    m = IRTools.meta(T)
    m isa Nothing && error("Error in remix!: could not derive lowered method body for $T.")
    ir = IRTools.IR(m)
    n_ir = remix!(ir)
    updated = update!(m.code, n_ir)
    pushfirst!(updated.slotnames, Symbol("#self#"))
    return updated
end