[libc] Add type_traits tests

[gchatelet]

This is not exhaustive for now but it provides a placeholder for invoke_result test mentioned in #65750.

[llvmbot]

@llvm/pr-subscribers-libc

Changes

None

Full diff: https://github.com/llvm/llvm-project/pull/65956.diff

3 Files Affected:

• (modified) libc/test/src/__support/CPP/CMakeLists.txt (+10)
• (added) libc/test/src/__support/CPP/type_traits_test.cpp (+268)
• (modified) utils/bazel/llvm-project-overlay/libc/test/src/__support/CPP/BUILD.bazel (+10)

diff --git a/libc/test/src/__support/CPP/CMakeLists.txt b/libc/test/src/__support/CPP/CMakeLists.txt
index be2bc20d780471a..5772a83a65cad13 100644
--- a/libc/test/src/__support/CPP/CMakeLists.txt
+++ b/libc/test/src/__support/CPP/CMakeLists.txt
@@ -106,3 +106,13 @@ add_libc_test(
   libc.src.__support.CPP.string
   libc.src.__support.CPP.string_view
 )
+
+add_libc_test(
+  type_traits_test
+  SUITE
+    libc-cpp-utils-tests
+  SRCS
+  type_traits_test.cpp
+  DEPENDS
+  libc.src.__support.CPP.type_traits
+)
diff --git a/libc/test/src/__support/CPP/type_traits_test.cpp b/libc/test/src/__support/CPP/type_traits_test.cpp
new file mode 100644
index 000000000000000..69b7009e636b3a8
--- /dev/null
+++ b/libc/test/src/__support/CPP/type_traits_test.cpp
@@ -0,0 +1,268 @@
+//===-- Unittests for type_traits -----------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/CPP/type_traits.h"
+#include "test/UnitTest/Test.h"
+
+// TODO: Split this file if it becomes too big.
+
+namespace __llvm_libc::cpp {
+
+class Class {};
+union Union {};
+struct Struct {};
+
+using UnqualObjectTypes = testing::TypeList;
+
+TYPED_TEST(LlvmLibcTypeTraitsTest, add_lvalue_reference, UnqualObjectTypes) {
+
+  // non-ref cv, adds ref
+  EXPECT_TRUE((is_same_v, T &>));
+  EXPECT_TRUE((is_same_v, const T &>));
+  EXPECT_TRUE((is_same_v, volatile T &>));
+  EXPECT_TRUE((
+      is_same_v, const volatile T &>));
+
+  // ref cv, returns same type
+  EXPECT_TRUE((is_same_v, T &>));
+  EXPECT_TRUE((is_same_v, const T &>));
+  EXPECT_TRUE((is_same_v, volatile T &>));
+  EXPECT_TRUE((is_same_v,
+                         const volatile T &>));
+}
+
+TEST(LlvmLibcTypeTraitsTest, add_lvalue_reference_void) {
+  // void cannot be referenced
+  EXPECT_TRUE((is_same_v, void>));
+  EXPECT_TRUE((is_same_v, const void>));
+  EXPECT_TRUE(
+      (is_same_v, volatile void>));
+  EXPECT_TRUE((is_same_v,
+                         const volatile void>));
+}
+
+TYPED_TEST(LlvmLibcTypeTraitsTest, add_pointer, UnqualObjectTypes) {
+  // object types -> pointer type
+  EXPECT_TRUE((is_same_v, T *>));
+  EXPECT_TRUE((is_same_v, const T *>));
+  EXPECT_TRUE((is_same_v, volatile T *>));
+  EXPECT_TRUE((is_same_v, const volatile T *>));
+
+  // reference type -> pointer type
+  EXPECT_TRUE((is_same_v, T *>));
+  EXPECT_TRUE((is_same_v, const T *>));
+  EXPECT_TRUE((is_same_v, volatile T *>));
+  EXPECT_TRUE(
+      (is_same_v, const volatile T *>));
+}
+
+TEST(LlvmLibcTypeTraitsTest, add_pointer_void) {
+  // void -> pointer type
+  EXPECT_TRUE((is_same_v, void *>));
+  EXPECT_TRUE((is_same_v, const void *>));
+  EXPECT_TRUE((is_same_v, volatile void *>));
+  EXPECT_TRUE(
+      (is_same_v, const volatile void *>));
+}
+
+TYPED_TEST(LlvmLibcTypeTraitsTest, add_rvalue_reference, UnqualObjectTypes) {
+
+  // non-ref cv, adds ref
+  EXPECT_TRUE((is_same_v, T &&>));
+  EXPECT_TRUE((is_same_v, const T &&>));
+  EXPECT_TRUE((is_same_v, volatile T &&>));
+  EXPECT_TRUE((is_same_v,
+                         const volatile T &&>));
+
+  // ref cv, returns same type
+  EXPECT_TRUE((is_same_v, T &>));
+  EXPECT_TRUE((is_same_v, const T &>));
+  EXPECT_TRUE((is_same_v, volatile T &>));
+  EXPECT_TRUE((is_same_v,
+                         const volatile T &>));
+}
+
+TEST(LlvmLibcTypeTraitsTest, add_rvalue_reference_void) {
+  // void cannot be referenced
+  EXPECT_TRUE((is_same_v, void>));
+  EXPECT_TRUE((is_same_v, const void>));
+  EXPECT_TRUE(
+      (is_same_v, volatile void>));
+  EXPECT_TRUE((is_same_v,
+                         const volatile void>));
+}
+
+TEST(LlvmLibcTypeTraitsTest, bool_constant) {
+  EXPECT_TRUE((bool_constant::value));
+  EXPECT_FALSE((bool_constant::value));
+}
+
+TEST(LlvmLibcTypeTraitsTest, conditional_t) {
+  EXPECT_TRUE((is_same_v, int>));
+  EXPECT_TRUE((is_same_v, float>));
+}
+
+TEST(LlvmLibcTypeTraitsTest, decay) {
+  EXPECT_TRUE((is_same_v, int>));
+
+  // array decay
+  EXPECT_TRUE((is_same_v, int *>));
+  EXPECT_TRUE((is_same_v, int *>));
+  EXPECT_TRUE((is_same_v, int(*)[4]>));
+
+  // cv ref decay
+  EXPECT_TRUE((is_same_v, int>));
+  EXPECT_TRUE((is_same_v, int>));
+  EXPECT_TRUE((is_same_v, int>));
+  EXPECT_TRUE((is_same_v, int>));
+}
+
+// TODO enable_if
+
+TEST(LlvmLibcTypeTraitsTest, false_type) { EXPECT_FALSE((false_type::value)); }
+
+TEST(LlvmLibcTypeTraitsTest, integral_constant) {
+  EXPECT_EQ((integral_constant::value), 4);
+}
+
+using IntegralTypes =
+    testing::TypeList;
+
+TYPED_TEST(LlvmLibcTypeTraitsTest, is_arithmetic, IntegralTypes) {
+  EXPECT_TRUE((is_arithmetic_v));
+  EXPECT_TRUE((is_arithmetic_v));
+  EXPECT_TRUE((is_arithmetic_v));
+  EXPECT_TRUE((is_arithmetic_v));
+
+  EXPECT_FALSE((is_arithmetic_v));
+  EXPECT_FALSE((is_arithmetic_v));
+}
+
+TEST(LlvmLibcTypeTraitsTest, is_arithmetic_non_integral) {
+  EXPECT_FALSE((is_arithmetic_v));
+  EXPECT_FALSE((is_arithmetic_v));
+  EXPECT_FALSE((is_arithmetic_v));
+}
+
+TEST(LlvmLibcTypeTraitsTest, is_array) {
+  EXPECT_FALSE((is_array_v));
+  EXPECT_FALSE((is_array_v));
+  EXPECT_FALSE((is_array_v));
+
+  EXPECT_TRUE((is_array_v));
+  EXPECT_TRUE((is_array_v));
+}
+
+TEST(LlvmLibcTypeTraitsTest, is_base_of) {
+  struct A {};
+  EXPECT_TRUE((is_base_of_v));
+
+  struct B : public A {};
+  EXPECT_TRUE((is_base_of_v));
+  EXPECT_FALSE((is_base_of_v));
+
+  struct C : protected A {};
+  EXPECT_TRUE((is_base_of_v));
+  EXPECT_FALSE((is_base_of_v));
+
+  struct D : private A {};
+  EXPECT_TRUE((is_base_of_v));
+  EXPECT_FALSE((is_base_of_v));
+}
+
+TEST(LlvmLibcTypeTraitsTest, is_class) {
+  EXPECT_TRUE((is_class_v));
+  EXPECT_TRUE((is_class_v));
+  EXPECT_FALSE((is_class_v));
+  EXPECT_FALSE((is_class_v));
+}
+
+TYPED_TEST(LlvmLibcTypeTraitsTest, is_const, UnqualObjectTypes) {
+  EXPECT_FALSE((is_const_v));
+  EXPECT_TRUE((is_const_v));
+}
+
+// TODO is_convertible
+
+TYPED_TEST(LlvmLibcTypeTraitsTest, is_destructible, UnqualObjectTypes) {
+  EXPECT_TRUE((is_destructible_v));
+}
+TEST(LlvmLibcTypeTraitsTest, is_destructible_no_destructor) {
+  struct S {
+    ~S() = delete;
+  };
+  EXPECT_FALSE((is_destructible_v));
+}
+
+TYPED_TEST(LlvmLibcTypeTraitsTest, is_enum, UnqualObjectTypes) {
+  EXPECT_FALSE((is_enum_v));
+}
+TEST(LlvmLibcTypeTraitsTest, is_enum_enum) {
+  enum Enum {};
+  EXPECT_TRUE((is_enum_v));
+}
+
+// TODO is_floating_point
+
+// TODO is_function
+
+// TODO is_integral
+
+// TODO is_lvalue_reference
+
+// TODO is_member_pointer
+
+// TODO is_null_pointer
+
+// TODO is_pointer
+
+// TODO is_reference
+
+// TODO is_rvalue_reference
+
+// TODO is_same
+
+// TODO is_scalar
+
+// TODO is_signed
+
+// TODO is_trivially_constructible
+
+// TODO is_trivially_copyable
+
+// TODO is_trivially_destructible
+
+// TODO is_union
+
+// TODO is_unsigned
+
+// TODO is_void
+
+// TODO make_signed
+
+// TODO make_unsigned
+
+// TODO remove_all_extents
+
+// TODO remove_cv
+
+// TODO remove_cvref
+
+// TODO remove_extent
+
+// TODO remove_reference
+
+TEST(LlvmLibcTypeTraitsTest, true_type) { EXPECT_TRUE((true_type::value)); }
+
+// TODO type_identity
+
+// TODO void_t
+
+} // namespace __llvm_libc::cpp
diff --git a/utils/bazel/llvm-project-overlay/libc/test/src/__support/CPP/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/test/src/__support/CPP/BUILD.bazel
index c74f9821849a7a0..5ebd8260035792d 100644
--- a/utils/bazel/llvm-project-overlay/libc/test/src/__support/CPP/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/test/src/__support/CPP/BUILD.bazel
@@ -110,3 +110,13 @@ cc_test(
         "//libc/test/UnitTest:LibcUnitTest",
     ],
 )
+
+cc_test(
+    name = "type_traits_test",
+    srcs = ["type_traits_test.cpp"],
+    deps = [
+        "//libc:__support_cpp_type_traits",
+        "//libc:libc_root",
+        "//libc/test/UnitTest:LibcUnitTest",
+    ],
+)

[gchatelet]

The buildkite failure is unrelated to this patch.