Inferrability: eliminate more Core.Box (JuliaLang#44029)

These stem from julia#15276, i.e.,
https://docs.julialang.org/en/v1/manual/performance-tips/#man-performance-captured
They were identified by scanning all compiled MethodInstances with
hasbox in the newly-released MethodAnalysis 0.4.5.

Core.Box often causes "follow-on" inference problems,
but for these cases there were relatively few, which may be why
these didn't show up earlier during the Great Invalidation Hunt.
Still, there doesn't seem to be any particular reason not to fix them.

This doesn't eliminate all Core.Box cases from Base, but only a
handful remain. The most common remaining case stems from inner
functions calling themselves.

It also prevents a couple of Test invalidations

Co-authored-by: Jameson Nash <[email protected]>

base/compiler/ssair/show.jl

@@ -629,8 +629,10 @@ function show_ir_stmt(io::IO, code::Union{IRCode, CodeInfo}, idx::Int, line_info
 
  @assert new_node_inst !== UNDEF # we filtered these out earlier
  show_type = should_print_ssa_type(new_node_inst)
- with_output_color(:green, io) do io′
- print_stmt(io′, node_idx, new_node_inst, used, maxlength_idx, false, show_type)
+ let maxlength_idx=maxlength_idx, show_type=show_type
+ with_output_color(:green, io) do io′
+ print_stmt(io′, node_idx, new_node_inst, used, maxlength_idx, false, show_type)
+ end
  end
 
  if new_node_type === UNDEF # try to be robust against errors

base/errorshow.jl

@@ -345,13 +345,15 @@ function showerror_ambiguous(io::IO, meth, f, args)
  sigfix = typeintersect(m.sig, sigfix)
  end
  if isa(unwrap_unionall(sigfix), DataType) && sigfix <: Tuple
- if all(m->morespecific(sigfix, m.sig), meth)
- print(io, "\nPossible fix, define\n ")
- Base.show_tuple_as_call(io, :function, sigfix)
- else
- println(io)
- print(io, "To resolve the ambiguity, try making one of the methods more specific, or ")
- print(io, "adding a new method more specific than any of the existing applicable methods.")
+ let sigfix=sigfix
+ if all(m->morespecific(sigfix, m.sig), meth)
+ print(io, "\nPossible fix, define\n ")
+ Base.show_tuple_as_call(io, :function, sigfix)
+ else
+ println(io)
+ print(io, "To resolve the ambiguity, try making one of the methods more specific, or ")
+ print(io, "adding a new method more specific than any of the existing applicable methods.")
+ end
  end
  end
  nothing

base/shell.jl

@@ -211,8 +211,8 @@ function print_shell_escaped_posixly(io::IO, args::AbstractString...)
  first || print(io, ' ')
  # avoid printing quotes around simple enough strings
  # that any (reasonable) shell will definitely never consider them to be special
- have_single = false
- have_double = false
+ have_single::Bool = false
+ have_double::Bool = false
  function isword(c::AbstractChar)
  if '0' <= c <= '9' || 'a' <= c <= 'z' || 'A' <= c <= 'Z'
  # word characters

base/weakkeydict.jl

@@ -130,7 +130,7 @@ end
 
 function getkey(wkh::WeakKeyDict{K}, kk, default) where K
  k = lock(wkh) do
- k = getkey(wkh.ht, kk, nothing)
+ local k = getkey(wkh.ht, kk, nothing)
  k === nothing && return nothing
  return k.value
  end

stdlib/REPL/src/LineEdit.jl

@@ -1971,7 +1971,7 @@ function enter_prefix_search(s::MIState, p::PrefixHistoryPrompt, backward::Bool)
  parent = mode(s)
 
  transition(s, p) do
- pss = state(s, p)
+ local pss = state(s, p)
  pss.parent = parent
  pss.histprompt.parent_prompt = parent
  pss.prefix = String(buf.data[1:position(buf)])

stdlib/Test/src/Test.jl

@@ -87,7 +87,7 @@ struct Pass <: Result
  value
  source::Union{Nothing,LineNumberNode}
  message_only::Bool
- function Pass(test_type::Symbol, orig_expr, data, thrown, source=nothing, message_only=false)
+ function Pass(test_type::Symbol, orig_expr, data, thrown, source::Union{Nothing,LineNumberNode}=nothing, message_only::Bool=false)
  return new(test_type, orig_expr, data, thrown, source, message_only)
  end
 end
@@ -168,7 +168,7 @@ struct Error <: Result
  backtrace::String
  source::LineNumberNode
 
- function Error(test_type, orig_expr, value, bt, source)
+ function Error(test_type::Symbol, orig_expr, value, bt, source::LineNumberNode)
  if test_type === :test_error
  bt = scrub_exc_stack(bt)
  end