missing nospecialize on some macro arguments

[vtjnash]

Notice how b is missing nospecialize where it exists in the second body, since it has a default value in the first body. I noticed this when I was testing some precompile statements and surprised to see some failing.

julia> Meta.@lower macro foo(a, b=2) nothing end
:($(Expr(:thunk, CodeInfo(
    @ none within `top-level scope'
1 ─       $(Expr(:thunk, CodeInfo(
    @ none within `top-level scope'
1 ─     return $(Expr(:method, Symbol("@foo")))
)))
│         $(Expr(:method, Symbol("@foo")))
│   %3  = Core.Typeof(var"@foo")
│   %4  = Core.svec(%3, Core.LineNumberNode, Core.Module, Core.Any)
│   %5  = Core.svec()
│   %6  = Core.svec(%4, %5, $(QuoteNode(:(#= REPL[5]:1 =#))))
│         $(Expr(:method, Symbol("@foo"), :(%6), CodeInfo(
    @ REPL[5]:1 within none
1 ─      $(Expr(:meta, :nospecialize, :(a)))
│   %2 = (#self#)(__source__, __module__, a, 2)
└──      return %2
)))
│         $(Expr(:method, Symbol("@foo")))
│   %9  = Core.Typeof(var"@foo")
│   %10 = Core.svec(%9, Core.LineNumberNode, Core.Module, Core.Any, Core.Any)
│   %11 = Core.svec()
│   %12 = Core.svec(%10, %11, $(QuoteNode(:(#= REPL[5]:1 =#))))
│         $(Expr(:method, Symbol("@foo"), :(%12), CodeInfo(
    @ REPL[5]:1 within none
1 ─     $(Expr(:meta, :nospecialize, :(a)))
└──     return nothing
)))
└──       return var"@foo"
))))

[vtjnash]

Relatedly, also missing on args...:

julia> Meta.@lower macro ncall(N::Int, f, args...) nothing end
:($(Expr(:thunk, CodeInfo(
    @ none within `top-level scope'
1 ─      $(Expr(:thunk, CodeInfo(
    @ none within `top-level scope'
1 ─     return $(Expr(:method, Symbol("@ncall")))
)))
│        $(Expr(:method, Symbol("@ncall")))
│   %3 = Core.Typeof(var"@ncall")
│   %4 = Core.apply_type(Vararg, Core.Any)
│   %5 = Core.svec(%3, Core.LineNumberNode, Core.Module, Int, Core.Any, %4)
│   %6 = Core.svec()
│   %7 = Core.svec(%5, %6, $(QuoteNode(:(#= REPL[5]:1 =#))))
│        $(Expr(:method, Symbol("@ncall"), :(%7), CodeInfo(
    @ REPL[5]:1 within `none'
1 ─     $(Expr(:meta, :nospecialize, :(f)))
└──     return nothing
)))
└──      return var"@ncall"
))))