replace use of () as a sentinel in inference with nothing (JuliaL…

…ang#30875)

base/compiler/abstractinterpretation.jl

@@ -446,7 +446,7 @@ function abstract_iteration(@nospecialize(itertype), vtypes::VarTable, sv::Infer
  return Any[Vararg{Any}]
  end
  iteratef = getfield(Main.Base, :iterate)
- stateordonet = abstract_call(iteratef, (), Any[Const(iteratef), itertype], vtypes, sv)
+ stateordonet = abstract_call(iteratef, nothing, Any[Const(iteratef), itertype], vtypes, sv)
  # Return Bottom if this is not an iterator.
  # WARNING: Changes to the iteration protocol must be reflected here,
  # this is not just an optimization.
@@ -465,7 +465,7 @@ function abstract_iteration(@nospecialize(itertype), vtypes::VarTable, sv::Infer
  valtype = stateordonet.parameters[1]
  statetype = stateordonet.parameters[2]
  push!(ret, valtype)
- stateordonet = abstract_call(iteratef, (), Any[Const(iteratef), itertype, statetype], vtypes, sv)
+ stateordonet = abstract_call(iteratef, nothing, Any[Const(iteratef), itertype, statetype], vtypes, sv)
  stateordonet = widenconst(stateordonet)
  end
  if stateordonet === Nothing
@@ -482,7 +482,7 @@ function abstract_iteration(@nospecialize(itertype), vtypes::VarTable, sv::Infer
  end
  valtype = tmerge(valtype, nounion.parameters[1])
  statetype = tmerge(statetype, nounion.parameters[2])
- stateordonet = abstract_call(iteratef, (), Any[Const(iteratef), itertype, statetype], vtypes, sv)
+ stateordonet = abstract_call(iteratef, nothing, Any[Const(iteratef), itertype, statetype], vtypes, sv)
  stateordonet = widenconst(stateordonet)
  end
  push!(ret, Vararg{valtype})
@@ -524,9 +524,9 @@ function abstract_apply(@nospecialize(aft), aargtypes::Vector{Any}, vtypes::VarT
  end
  for ct in ctypes
  if isa(aft, Const)
- rt = abstract_call(aft.val, (), ct, vtypes, sv, max_methods)
+ rt = abstract_call(aft.val, nothing, ct, vtypes, sv, max_methods)
  elseif isconstType(aft)
- rt = abstract_call(aft.parameters[1], (), ct, vtypes, sv, max_methods)
+ rt = abstract_call(aft.parameters[1], nothing, ct, vtypes, sv, max_methods)
  else
  astype = argtypes_to_type(ct)
  rt = abstract_call_gf_by_type(nothing, ct, astype, sv, max_methods)
@@ -570,7 +570,7 @@ function pure_eval_call(@nospecialize(f), argtypes::Vector{Any}, @nospecialize(a
  end
 end
 
-function abstract_call(@nospecialize(f), fargs::Union{Tuple{},Vector{Any}}, argtypes::Vector{Any}, vtypes::VarTable, sv::InferenceState, max_methods = sv.params.MAX_METHODS)
+function abstract_call(@nospecialize(f), fargs::Union{Nothing,Vector{Any}}, argtypes::Vector{Any}, vtypes::VarTable, sv::InferenceState, max_methods = sv.params.MAX_METHODS)
  if f === _apply
  return abstract_apply(argtypes[2], argtypes[3:end], vtypes, sv, max_methods)
  end
@@ -728,7 +728,7 @@ function abstract_call(@nospecialize(f), fargs::Union{Tuple{},Vector{Any}}, argt
  return Any
  elseif is_return_type(f)
  rt_rt = return_type_tfunc(argtypes, vtypes, sv)
- if rt_rt !== NOT_FOUND
+ if rt_rt !== nothing
  return rt_rt
  end
  elseif length(argtypes) == 2 && istopfunction(f, :!)
@@ -753,7 +753,7 @@ function abstract_call(@nospecialize(f), fargs::Union{Tuple{},Vector{Any}}, argt
  if length(fargs) == 3
  fargs = Any[<:, fargs[3], fargs[2]]
  else
- fargs = ()
+ fargs = nothing
  end
  argtypes = Any[typeof(<:), argtypes[3], argtypes[2]]
  rty = abstract_call(<:, fargs, argtypes, vtypes, sv)
@@ -785,7 +785,7 @@ function abstract_call(@nospecialize(f), fargs::Union{Tuple{},Vector{Any}}, argt
 end
 
 # wrapper around `abstract_call` for first computing if `f` is available
-function abstract_eval_call(fargs::Union{Tuple{},Vector{Any}}, argtypes::Vector{Any}, vtypes::VarTable, sv::InferenceState)
+function abstract_eval_call(fargs::Union{Nothing,Vector{Any}}, argtypes::Vector{Any}, vtypes::VarTable, sv::InferenceState)
  #print("call ", e.args[1], argtypes, "\n\n")
  for x in argtypes
  x === Bottom && return Bottom
@@ -859,7 +859,7 @@ function abstract_eval_cfunction(e::Expr, vtypes::VarTable, sv::InferenceState)
  # this may be the wrong world for the call,
  # but some of the result is likely to be valid anyways
  # and that may help generate better codegen
- abstract_eval_call((), at, vtypes, sv)
+ abstract_eval_call(nothing, at, vtypes, sv)
  nothing
 end
 
@@ -1035,7 +1035,7 @@ function typeinf_local(frame::InferenceState)
  delete!(W, pc)
  frame.currpc = pc
  frame.cur_hand = frame.handler_at[pc]
- frame.stmt_edges[pc] === () || empty!(frame.stmt_edges[pc])
+ frame.stmt_edges[pc] === nothing || empty!(frame.stmt_edges[pc])
  stmt = frame.src.code[pc]
  changes = s[pc]::VarTable
  t = nothing
@@ -1105,9 +1105,8 @@ function typeinf_local(frame::InferenceState)
  end
  elseif hd === :enter
  l = stmt.args[1]::Int
- frame.cur_hand = (l, frame.cur_hand)
+ frame.cur_hand = Pair{Any,Any}(l, frame.cur_hand)
  # propagate type info to exception handler
- l = frame.cur_hand[1]
  old = s[l]
  new = s[pc]::Array{Any,1}
  newstate_catch = stupdate!(old, new)
@@ -1122,7 +1121,7 @@ function typeinf_local(frame::InferenceState)
  frame.handler_at[l] = frame.cur_hand
  elseif hd === :leave
  for i = 1:((stmt.args[1])::Int)
- frame.cur_hand = frame.cur_hand[2]
+ frame.cur_hand = (frame.cur_hand::Pair{Any,Any}).second
  end
  else
  if hd === :(=)
@@ -1148,11 +1147,11 @@ function typeinf_local(frame::InferenceState)
  frame.src.ssavaluetypes[pc] = t
  end
  end
- if frame.cur_hand !== () && isa(changes, StateUpdate)
+ if frame.cur_hand !== nothing && isa(changes, StateUpdate)
  # propagate new type info to exception handler
  # the handling for Expr(:enter) propagates all changes from before the try/catch
  # so this only needs to propagate any changes
- l = frame.cur_hand[1]
+ l = frame.cur_hand.first::Int
  if stupdate1!(s[l]::VarTable, changes::StateUpdate) !== false
  if l < frame.pc´´
  frame.pc´´ = l

base/compiler/inferencestate.jl

@@ -25,7 +25,7 @@ mutable struct InferenceState
  pc´´::LineNum
  nstmts::Int
  # current exception handler info
- cur_hand #::Tuple{LineNum, Tuple{LineNum, ...}}
+ cur_hand #::Union{Nothing, Pair{LineNum, prev_handler}}
  handler_at::Vector{Any}
  n_handlers::Int
  # ssavalue sparsity and restart info
@@ -54,8 +54,8 @@ mutable struct InferenceState
  src.ssavaluetypes = Any[ NOT_FOUND for i = 1:nssavalues ]
 
  n = length(code)
- s_edges = Any[ () for i = 1:n ]
- s_types = Any[ () for i = 1:n ]
+ s_edges = Any[ nothing for i = 1:n ]
+ s_types = Any[ nothing for i = 1:n ]
 
  # initial types
  nslots = length(src.slotnames)
@@ -73,8 +73,8 @@ mutable struct InferenceState
  ssavalue_uses = find_ssavalue_uses(code, nssavalues)
 
  # exception handlers
- cur_hand = ()
- handler_at = Any[ () for i=1:n ]
+ cur_hand = nothing
+ handler_at = Any[ nothing for i=1:n ]
  n_handlers = 0
 
  W = BitSet()
@@ -186,7 +186,7 @@ function record_ssa_assign(ssa_id::Int, @nospecialize(new), frame::InferenceStat
  W = frame.ip
  s = frame.stmt_types
  for r in frame.ssavalue_uses[ssa_id]
- if s[r] !== () # s[r] === () => unreached statement
+ if s[r] !== nothing # s[r] === nothing => unreached statement
  if r < frame.pc´´
  frame.pc´´ = r
  end
@@ -207,7 +207,7 @@ end
 # temporarily accumulate our edges to later add as backedges in the callee
 function add_backedge!(li::MethodInstance, caller::InferenceState)
  isa(caller.linfo.def, Method) || return # don't add backedges to toplevel exprs
- if caller.stmt_edges[caller.currpc] === ()
+ if caller.stmt_edges[caller.currpc] === nothing
  caller.stmt_edges[caller.currpc] = []
  end
  push!(caller.stmt_edges[caller.currpc], li)
@@ -218,7 +218,7 @@ end
 # used to temporarily accumulate our no method errors to later add as backedges in the callee method table
 function add_mt_backedge!(mt::Core.MethodTable, @nospecialize(typ), caller::InferenceState)
  isa(caller.linfo.def, Method) || return # don't add backedges to toplevel exprs
- if caller.stmt_edges[caller.currpc] === ()
+ if caller.stmt_edges[caller.currpc] === nothing
  caller.stmt_edges[caller.currpc] = []
  end
  push!(caller.stmt_edges[caller.currpc], mt)

base/compiler/optimize.jl

@@ -18,7 +18,7 @@ mutable struct OptimizationState
  const_api::Bool
  function OptimizationState(frame::InferenceState)
  s_edges = frame.stmt_edges[1]
- if s_edges === ()
+ if s_edges === nothing
  s_edges = []
  frame.stmt_edges[1] = s_edges
  end

base/compiler/ssair/ir.jl

@@ -1195,7 +1195,6 @@ function fixup_node(compact::IncrementalCompact, @nospecialize(stmt))
  return compact.ssa_rename[stmt.id]
  else
  urs = userefs(stmt)
- urs === () && return stmt
  for ur in urs
  val = ur[]
  if isa(val, NewSSAValue)

base/compiler/ssair/slot2ssa.jl

@@ -660,7 +660,7 @@ function construct_ssa!(ci::CodeInfo, code::Vector{Any}, ir::IRCode, domtree::Do
  visited = BitSet()
  type_refine_phi = BitSet()
  @timeit "SSA Rename" while !isempty(worklist)
- (item, pred, incoming_vals) = pop!(worklist)
+ (item::Int, pred, incoming_vals) = pop!(worklist)
  # Rename existing phi nodes first, because their uses occur on the edge
  # TODO: This isn't necessary if inlining stops replacing arguments by slots.
  for idx in cfg.blocks[item].stmts

base/compiler/tfuncs.jl

@@ -1330,9 +1330,9 @@ function return_type_tfunc(argtypes::Vector{Any}, vtypes::VarTable, sv::Inferenc
  end
  astype = argtypes_to_type(argtypes_vec)
  if isa(aft, Const)
- rt = abstract_call(aft.val, (), argtypes_vec, vtypes, sv, -1)
+ rt = abstract_call(aft.val, nothing, argtypes_vec, vtypes, sv, -1)
  elseif isconstType(aft)
- rt = abstract_call(aft.parameters[1], (), argtypes_vec, vtypes, sv, -1)
+ rt = abstract_call(aft.parameters[1], nothing, argtypes_vec, vtypes, sv, -1)
  else
  rt = abstract_call_gf_by_type(nothing, argtypes_vec, astype, sv, -1)
  end
@@ -1356,7 +1356,7 @@ function return_type_tfunc(argtypes::Vector{Any}, vtypes::VarTable, sv::Inferenc
  end
  end
  end
- return NOT_FOUND
+ return nothing
 end
 
 # N.B.: typename maps type equivalence classes to a single value

base/compiler/typeinfer.jl

@@ -190,6 +190,7 @@ function store_backedges(frame::InferenceState)
  if !toplevel && (frame.cached || frame.parent !== nothing)
  caller = frame.result.linfo
  for edges in frame.stmt_edges
+ edges === nothing && continue
  i = 1
  while i <= length(edges)
  to = edges[i]
@@ -314,7 +315,7 @@ function type_annotate!(sv::InferenceState)
  src = sv.src
  states = sv.stmt_types
  nargs = sv.nargs
- nslots = length(states[1])
+ nslots = length(states[1]::Array{Any,1})
  undefs = fill(false, nslots)
  body = src.code::Array{Any,1}
  nexpr = length(body)
@@ -339,7 +340,7 @@ function type_annotate!(sv::InferenceState)
  st_i = states[i]
  expr = body[i]
  if isa(st_i, VarTable)
- # st_i === () => unreached statement (see issue #7836)
+ # st_i === nothing => unreached statement (see issue #7836)
  if isa(expr, Expr)
  annotate_slot_load!(expr, st_i, sv, undefs)
  elseif isa(expr, Slot)

base/compiler/typelattice.jl

@@ -228,7 +228,7 @@ function widenconditional(typ::Conditional)
  end
 end
 
-function stupdate!(state::Tuple{}, changes::StateUpdate)
+function stupdate!(state::Nothing, changes::StateUpdate)
  newst = copy(changes.state)
  if isa(changes.var, Slot)
  changeid = slot_id(changes.var::Slot)
@@ -288,9 +288,9 @@ function stupdate!(state::VarTable, changes::VarTable)
  return newstate
 end
 
-stupdate!(state::Tuple{}, changes::VarTable) = copy(changes)
+stupdate!(state::Nothing, changes::VarTable) = copy(changes)
 
-stupdate!(state::Tuple{}, changes::Tuple{}) = false
+stupdate!(state::Nothing, changes::Nothing) = false
 
 function stupdate1!(state::VarTable, change::StateUpdate)
  if !isa(change.var, Slot)