[compiler-rt] [scudo] Group type traits into a single header (NFC) (PR #118888)

[via llvm-commits]

https://github.com/ChiaHungDuan updated https://github.com/llvm/llvm-project/pull/118888

>From 4b625833ef09b7abab60e21f560c352de1c9febc Mon Sep 17 00:00:00 2001
From: Chia-hung Duan <chiahungduan at google.com>
Date: Thu, 5 Dec 2024 22:11:13 +0000
Subject: [PATCH] [scudo] Group type traits into a single header (NFC)

---
 .../lib/scudo/standalone/CMakeLists.txt       |  1 +
 .../standalone/allocator_config_wrapper.h     | 30 +-----------
 compiler-rt/lib/scudo/standalone/list.h       | 12 +----
 .../lib/scudo/standalone/type_traits.h        | 47 +++++++++++++++++++
 4 files changed, 50 insertions(+), 40 deletions(-)
 create mode 100644 compiler-rt/lib/scudo/standalone/type_traits.h

diff --git a/compiler-rt/lib/scudo/standalone/CMakeLists.txt b/compiler-rt/lib/scudo/standalone/CMakeLists.txt
index dc700cec9becbf..3f9ae866a75533 100644
--- a/compiler-rt/lib/scudo/standalone/CMakeLists.txt
+++ b/compiler-rt/lib/scudo/standalone/CMakeLists.txt
@@ -98,6 +98,7 @@ set(SCUDO_HEADERS
   tsd_exclusive.h
   tsd_shared.h
   tsd.h
+  type_traits.h
   vector.h
   wrappers_c_checks.h
   wrappers_c.h
diff --git a/compiler-rt/lib/scudo/standalone/allocator_config_wrapper.h b/compiler-rt/lib/scudo/standalone/allocator_config_wrapper.h
index 5477236ac1f397..ea12a5b1447f69 100644
--- a/compiler-rt/lib/scudo/standalone/allocator_config_wrapper.h
+++ b/compiler-rt/lib/scudo/standalone/allocator_config_wrapper.h
@@ -12,35 +12,7 @@
 #include "condition_variable.h"
 #include "internal_defs.h"
 #include "secondary.h"
-
-namespace {
-
-template <typename T> struct removeConst {
-  using type = T;
-};
-template <typename T> struct removeConst<const T> {
-  using type = T;
-};
-
-// This is only used for SFINAE when detecting if a type is defined.
-template <typename T> struct voidAdaptor {
-  using type = void;
-};
-
-// This is used for detecting the case that defines the flag with wrong type and
-// it'll be viewed as undefined optional flag.
-template <typename L, typename R> struct assertSameType {
-  template <typename, typename> struct isSame {
-    static constexpr bool value = false;
-  };
-  template <typename T> struct isSame<T, T> {
-    static constexpr bool value = true;
-  };
-  static_assert(isSame<L, R>::value, "Flag type mismatches");
-  using type = R;
-};
-
-} // namespace
+#include "type_traits.h"
 
 namespace scudo {
 
diff --git a/compiler-rt/lib/scudo/standalone/list.h b/compiler-rt/lib/scudo/standalone/list.h
index c6bd32a8fa3251..5c34cbb049e602 100644
--- a/compiler-rt/lib/scudo/standalone/list.h
+++ b/compiler-rt/lib/scudo/standalone/list.h
@@ -10,17 +10,7 @@
 #define SCUDO_LIST_H_
 
 #include "internal_defs.h"
-
-// TODO: Move the helpers to a header.
-namespace {
-template <typename T> struct isPointer {
-  static constexpr bool value = false;
-};
-
-template <typename T> struct isPointer<T *> {
-  static constexpr bool value = true;
-};
-} // namespace
+#include "type_traits.h"
 
 namespace scudo {
 
diff --git a/compiler-rt/lib/scudo/standalone/type_traits.h b/compiler-rt/lib/scudo/standalone/type_traits.h
new file mode 100644
index 00000000000000..16ed5a048f82bc
--- /dev/null
+++ b/compiler-rt/lib/scudo/standalone/type_traits.h
@@ -0,0 +1,47 @@
+//===-- type_traits.h -------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SCUDO_TYPE_TRAITS_H_
+#define SCUDO_TYPE_TRAITS_H_
+
+namespace scudo {
+
+template <typename T> struct removeConst {
+  using type = T;
+};
+template <typename T> struct removeConst<const T> {
+  using type = T;
+};
+
+// This is only used for SFINAE when detecting if a type is defined.
+template <typename T> struct voidAdaptor {
+  using type = void;
+};
+
+template <typename L, typename R> struct assertSameType {
+  template <typename, typename> struct isSame {
+    static constexpr bool value = false;
+  };
+  template <typename T> struct isSame<T, T> {
+    static constexpr bool value = true;
+  };
+  static_assert(isSame<L, R>::value, "Type mismatches");
+  using type = R;
+};
+
+template <typename T> struct isPointer {
+  static constexpr bool value = false;
+};
+
+template <typename T> struct isPointer<T *> {
+  static constexpr bool value = true;
+};
+
+} // namespace scudo
+
+#endif // SCUDO_TYPE_TRAITS_H_