From 8e77b63fa7636f84767329dd298817d0a36b5ae3 Mon Sep 17 00:00:00 2001
From: Jameson Nash <vtjnash@gmail.com>
Date: Fri, 8 Sep 2023 10:59:21 -0400
Subject: [PATCH] refine effects of some reflection queries (#51235)

---
 base/essentials.jl | 4 ++++
 base/reflection.jl | 4 ++++
 src/jltypes.c      | 2 +-
 test/core.jl       | 2 +-
 4 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/base/essentials.jl b/base/essentials.jl
index db47f1ee7f2c1..4323052d540da 100644
--- a/base/essentials.jl
+++ b/base/essentials.jl
@@ -383,6 +383,7 @@ tail(x::Tuple) = argtail(x...)
 tail(::Tuple{}) = throw(ArgumentError("Cannot call tail on an empty tuple."))
 
 function unwrap_unionall(@nospecialize(a))
+    @_foldable_meta
     while isa(a,UnionAll)
         a = a.body
     end
@@ -390,6 +391,7 @@ function unwrap_unionall(@nospecialize(a))
 end
 
 function rewrap_unionall(@nospecialize(t), @nospecialize(u))
+    @_foldable_meta
     if !isa(u, UnionAll)
         return t
     end
@@ -397,6 +399,7 @@ function rewrap_unionall(@nospecialize(t), @nospecialize(u))
 end
 
 function rewrap_unionall(t::Core.TypeofVararg, @nospecialize(u))
+    @_foldable_meta
     isdefined(t, :T) || return t
     if !isa(u, UnionAll)
         return t
@@ -424,6 +427,7 @@ function isvarargtype(@nospecialize(t))
 end
 
 function isvatuple(@nospecialize(t))
+    @_foldable_meta
     t = unwrap_unionall(t)
     if isa(t, DataType)
         n = length(t.parameters)
diff --git a/base/reflection.jl b/base/reflection.jl
index 242d628161928..8a74099039da5 100644
--- a/base/reflection.jl
+++ b/base/reflection.jl
@@ -257,11 +257,13 @@ end
 Determine whether a field `s` is declared `const` in a given type `t`.
 """
 function isconst(@nospecialize(t::Type), s::Symbol)
+    @_foldable_meta
     t = unwrap_unionall(t)
     isa(t, DataType) || return false
     return isconst(t, fieldindex(t, s, false))
 end
 function isconst(@nospecialize(t::Type), s::Int)
+    @_foldable_meta
     t = unwrap_unionall(t)
     # TODO: what to do for `Union`?
     isa(t, DataType) || return false # uncertain
@@ -279,11 +281,13 @@ end
 Determine whether a field `s` is declared `@atomic` in a given type `t`.
 """
 function isfieldatomic(@nospecialize(t::Type), s::Symbol)
+    @_foldable_meta
     t = unwrap_unionall(t)
     isa(t, DataType) || return false
     return isfieldatomic(t, fieldindex(t, s, false))
 end
 function isfieldatomic(@nospecialize(t::Type), s::Int)
+    @_foldable_meta
     t = unwrap_unionall(t)
     # TODO: what to do for `Union`?
     isa(t, DataType) || return false # uncertain
diff --git a/src/jltypes.c b/src/jltypes.c
index 15da9448fa3e1..4e566339e3014 100644
--- a/src/jltypes.c
+++ b/src/jltypes.c
@@ -2610,7 +2610,7 @@ void jl_init_types(void) JL_GC_DISABLED
                                                     "hash", "n_uninitialized",
                                                     "flags", // "abstract", "mutable", "mayinlinealloc",
                                                     "max_methods");
-    const static uint32_t typename_constfields[1] = { 0x00003a3f }; // (1<<0)|(1<<1)|(1<<2)|(1<<3)|(1<<4)|(1<<5)|(1<<9)|(1<<11)|(1<<12)|(1<<13)
+    const static uint32_t typename_constfields[1] = { 0x00003a27 }; // (1<<0)|(1<<1)|(1<<2)|(1<<5)|(1<<9)|(1<<11)|(1<<12)|(1<<13) ; TODO: put back (1<<3)|(1<<4) in this list
     const static uint32_t typename_atomicfields[1] = { 0x00000180 }; // (1<<7)|(1<<8)
     jl_typename_type->name->constfields = typename_constfields;
     jl_typename_type->name->atomicfields = typename_atomicfields;
diff --git a/test/core.jl b/test/core.jl
index e65cf08be9e15..658cbd63da181 100644
--- a/test/core.jl
+++ b/test/core.jl
@@ -20,7 +20,7 @@ for (T, c) in (
         (Core.MethodTable, [:module]),
         (Core.TypeMapEntry, [:sig, :simplesig, :guardsigs, :min_world, :max_world, :func, :isleafsig, :issimplesig, :va]),
         (Core.TypeMapLevel, []),
-        (Core.TypeName, [:name, :module, :names, :atomicfields, :constfields, :wrapper, :mt, :hash, :n_uninitialized, :flags]),
+        (Core.TypeName, [:name, :module, :names, :wrapper, :mt, :hash, :n_uninitialized, :flags]),
         (DataType, [:name, :super, :parameters, :instance, :hash]),
         (TypeVar, [:name, :ub, :lb]),
     )