fix #44705, fix tuple_tfunc on Union containing Type{...}

Author: aviatesk

base/compiler/tfuncs.jl

@@ -1546,6 +1546,10 @@ function tuple_tfunc(argtypes::Vector{Any})
             params[i] = typeof(x.val)
         else
             x = isvarargtype(x) ? x : widenconst(x)
+            # since there don't exist any values whose runtime type are `Tuple{Type{...}}`,
+            # here we should turn such `Type{...}`-parameters to valid parameters, e.g.
+            # (::Type{Int},) -> Tuple{DataType} (or PartialStruct for more accuracy)
+            # (::Union{Type{Int32},Type{Int64}}) -> Tuple{Type}
             if isType(x)
                 anyinfo = true
                 xparam = x.parameters[1]
@@ -1554,6 +1558,8 @@ function tuple_tfunc(argtypes::Vector{Any})
                 else
                     params[i] = Type
                 end
+            elseif !isvarargtype(x) && hasintersect(x, Type)
+                params[i] = Union{x, Type}
             else
                 params[i] = x
             end

test/compiler/inference.jl

@@ -1562,6 +1562,15 @@ end
 @test arraysize_tfunc(Vector, Float64) === Union{}
 @test arraysize_tfunc(String, Int) === Union{}
 
+let tuple_tfunc
+    function tuple_tfunc(@nospecialize xs...)
+        return Core.Compiler.tuple_tfunc(Any[xs...])
+    end
+    @test Core.Compiler.widenconst(tuple_tfunc(Type{Int})) === Tuple{DataType}
+    # https://github.com/JuliaLang/julia/issues/44705
+    @test tuple_tfunc(Union{Type{Int32},Type{Int64}}) === Tuple{Type}
+end
+
 function f23024(::Type{T}, ::Int) where T
     1 + 1
 end
@@ -2082,7 +2091,7 @@ let M = Module()
             obj = $(Expr(:new, M.BePartialStruct, 42, :cond))
             r1 = getfield(obj, :cond) ? 0 : a # r1::Union{Nothing,Int}, not r1::Int (because PartialStruct doesn't wrap Conditional)
             a = $(gensym(:anyvar))::Any
-            r2 = getfield(obj, :cond) ? a : nothing # r2::Any, not r2::Const(nothing) (we don't need to worry about constrait invalidation here)
+            r2 = getfield(obj, :cond) ? a : nothing # r2::Any, not r2::Const(nothing) (we don't need to worry about constraint invalidation here)
             return r1, r2 # ::Tuple{Union{Nothing,Int},Any}
         end |> only
     end