From 4779826657f5654ec323961a7c2d79c4f94a39a5 Mon Sep 17 00:00:00 2001
From: Shuhei Kadowaki <40514306+aviatesk@users.noreply.github.com>
Date: Sun, 9 Jan 2022 14:38:57 +0900
Subject: [PATCH] inference: follow up #43603, better `getfield_tfunc` impl
 (#43713)

---
 base/compiler/tfuncs.jl    | 26 +++++++++++++-------------
 test/compiler/inference.jl |  1 +
 2 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/base/compiler/tfuncs.jl b/base/compiler/tfuncs.jl
index 04d698fe89ec0f..65a86f262d9b39 100644
--- a/base/compiler/tfuncs.jl
+++ b/base/compiler/tfuncs.jl
@@ -795,17 +795,13 @@ function getfield_tfunc(s00, name, order, boundscheck)
 end
 getfield_tfunc(@nospecialize(s00), @nospecialize(name)) = _getfield_tfunc(s00, name, false)
 function _getfield_tfunc(@nospecialize(s00), @nospecialize(name), setfield::Bool)
-    s = unwrap_unionall(s00)
-    if isa(s, Union)
-        return tmerge(getfield_tfunc(rewrap_unionall(s.a, s00), name),
-                      getfield_tfunc(rewrap_unionall(s.b, s00), name))
-    elseif isa(s, Conditional)
+    if isa(s00, Conditional)
         return Bottom # Bool has no fields
-    elseif isa(s, Const) || isconstType(s)
-        if !isa(s, Const)
-            sv = s.parameters[1]
+    elseif isa(s00, Const) || isconstType(s00)
+        if !isa(s00, Const)
+            sv = s00.parameters[1]
         else
-            sv = s.val
+            sv = s00.val
         end
         if isa(name, Const)
             nv = name.val
@@ -845,11 +841,15 @@ function _getfield_tfunc(@nospecialize(s00), @nospecialize(name), setfield::Bool
                 return unwrapva(s00.fields[nv])
             end
         end
+    else
+        s = unwrap_unionall(s00)
     end
-    if isType(s) || !isa(s, DataType) || isabstracttype(s)
-        return Any
+    if isa(s, Union)
+        return tmerge(_getfield_tfunc(rewrap_unionall(s.a, s00), name, setfield),
+                      _getfield_tfunc(rewrap_unionall(s.b, s00), name, setfield))
     end
-    s = s::DataType
+    isa(s, DataType) || return Any
+    isabstracttype(s) && return Any
     if s <: Tuple && !(Int <: widenconst(name))
         return Bottom
     end
@@ -873,7 +873,7 @@ function _getfield_tfunc(@nospecialize(s00), @nospecialize(name), setfield::Bool
         if !(_ts <: Tuple)
             return Any
         end
-        return getfield_tfunc(_ts, name)
+        return _getfield_tfunc(_ts, name, setfield)
     end
     ftypes = datatype_fieldtypes(s)
     nf = length(ftypes)
diff --git a/test/compiler/inference.jl b/test/compiler/inference.jl
index 35d4e87c736fdb..a42ffbbe84db03 100644
--- a/test/compiler/inference.jl
+++ b/test/compiler/inference.jl
@@ -1728,6 +1728,7 @@ end
 @test setfield!_tfunc(Const(@__MODULE__), Const(:v), Int) === Union{}
 @test setfield!_tfunc(Const(@__MODULE__), Int, Int) === Union{}
 @test setfield!_tfunc(Module, Const(:v), Int) === Union{}
+@test setfield!_tfunc(Union{Module,Base.RefValue{Any}}, Const(:v), Int) === Union{}
 @test setfield!_tfunc(ABCDconst, Const(:a), Any) === Union{}
 @test setfield!_tfunc(ABCDconst, Const(:b), Any) === Union{}
 @test setfield!_tfunc(ABCDconst, Const(:d), Any) === Union{}