Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 160 insertions, 0 deletions

diff --git a/mfbt/tests/TestCompactPair.cpp b/mfbt/tests/TestCompactPair.cpp
new file mode 100644
index 0000000000..66300c338a
--- /dev/null
+++ b/mfbt/tests/TestCompactPair.cpp
@@ -0,0 +1,160 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <type_traits>
+
+#include "mozilla/Assertions.h"
+#include "mozilla/CompactPair.h"
+
+using mozilla::CompactPair;
+using mozilla::MakeCompactPair;
+
+// Sizes aren't part of the guaranteed CompactPair interface, but we want to
+// verify our attempts at compactness through EBO are moderately functional,
+// *somewhere*.
+#define INSTANTIATE(T1, T2, name, size)                                        \
+  CompactPair<T1, T2> name##_1(T1(0), T2(0));                                  \
+  static_assert(sizeof(name##_1.first()) > 0,                                  \
+                "first method should work on CompactPair<" #T1 ", " #T2 ">");  \
+                                                                               \
+  static_assert(sizeof(name##_1.second()) > 0,                                 \
+                "second method should work on CompactPair<" #T1 ", " #T2 ">"); \
+                                                                               \
+  static_assert(sizeof(name##_1) == (size),                                    \
+                "CompactPair<" #T1 ", " #T2 "> has an unexpected size");       \
+                                                                               \
+  CompactPair<T2, T1> name##_2(T2(0), T1(0));                                  \
+  static_assert(sizeof(name##_2.first()) > 0,                                  \
+                "first method should work on CompactPair<" #T2 ", " #T1 ">");  \
+                                                                               \
+  static_assert(sizeof(name##_2.second()) > 0,                                 \
+                "second method should work on CompactPair<" #T2 ", " #T1 ">"); \
+                                                                               \
+  static_assert(sizeof(name##_2) == (size),                                    \
+                "CompactPair<" #T2 ", " #T1 "> has an unexpected size");
+
+static constexpr std::size_t sizemax(std::size_t a, std::size_t b) {
+  return (a > b) ? a : b;
+}
+
+INSTANTIATE(int, int, prim1, 2 * sizeof(int));
+INSTANTIATE(int, long, prim2,
+            sizeof(long) + sizemax(sizeof(int), alignof(long)));
+
+struct EmptyClass {
+  explicit EmptyClass(int) {}
+};
+struct NonEmpty {
+  char mC;
+  explicit NonEmpty(int) : mC('\0') {}
+};
+
+INSTANTIATE(int, EmptyClass, both1, sizeof(int));
+INSTANTIATE(int, NonEmpty, both2, sizeof(int) + alignof(int));
+INSTANTIATE(EmptyClass, NonEmpty, both3, 1);
+
+struct A {
+  char dummy;
+  explicit A(int) : dummy('\0') {}
+};
+struct B : A {
+  explicit B(int aI) : A(aI) {}
+};
+
+INSTANTIATE(A, A, class1, 2);
+INSTANTIATE(A, B, class2, 2);
+INSTANTIATE(A, EmptyClass, class3, 1);
+
+struct EmptyNonMovableNonDefaultConstructible {
+  explicit EmptyNonMovableNonDefaultConstructible(int) {}
+
+  EmptyNonMovableNonDefaultConstructible(
+      const EmptyNonMovableNonDefaultConstructible&) = delete;
+  EmptyNonMovableNonDefaultConstructible(
+      EmptyNonMovableNonDefaultConstructible&&) = delete;
+  EmptyNonMovableNonDefaultConstructible& operator=(
+      const EmptyNonMovableNonDefaultConstructible&) = delete;
+  EmptyNonMovableNonDefaultConstructible& operator=(
+      EmptyNonMovableNonDefaultConstructible&&) = delete;
+};
+
+static void TestInPlaceConstruction() {
+  constexpr int firstValue = 42;
+  constexpr int secondValue = 43;
+
+  {
+    const CompactPair<EmptyNonMovableNonDefaultConstructible, int> pair{
+        std::piecewise_construct, std::tuple(firstValue),
+        std::tuple(secondValue)};
+    MOZ_RELEASE_ASSERT(pair.second() == secondValue);
+  }
+
+  {
+    const CompactPair<int, EmptyNonMovableNonDefaultConstructible> pair{
+        std::piecewise_construct, std::tuple(firstValue),
+        std::tuple(secondValue)};
+    MOZ_RELEASE_ASSERT(pair.first() == firstValue);
+  }
+
+  {
+    const CompactPair<int, int> pair{std::piecewise_construct,
+                                     std::tuple(firstValue),
+                                     std::tuple(secondValue)};
+    MOZ_RELEASE_ASSERT(pair.first() == firstValue);
+    MOZ_RELEASE_ASSERT(pair.second() == secondValue);
+  }
+
+  {
+    const CompactPair<EmptyNonMovableNonDefaultConstructible,
+                      EmptyNonMovableNonDefaultConstructible>
+        pair{std::piecewise_construct, std::tuple(firstValue),
+             std::tuple(secondValue)};
+
+    // nothing to assert here...
+  }
+}
+
+struct OtherEmpty : EmptyClass {
+  explicit OtherEmpty(int aI) : EmptyClass(aI) {}
+};
+
+// C++11 requires distinct objects of the same type, within the same "most
+// derived object", to have different addresses.  CompactPair allocates its
+// elements as two bases, a base and a member, or two members.  If the two
+// elements have non-zero size or are unrelated, no big deal.  But if they're
+// both empty and related, something -- possibly both -- must be inflated.
+// Exactly which are inflated depends which CompactPairHelper specialization is
+// used.  We could potentially assert something about size for this case, but
+// whatever we could assert would be very finicky.  Plus it's two empty classes
+// -- hardly likely. So don't bother trying to assert anything about this case.
+// INSTANTIATE(EmptyClass, OtherEmpty, class4, ...something finicky...);
+
+int main() {
+  A a(0);
+  B b(0);
+  const A constA(0);
+  const B constB(0);
+
+  // Check that MakeCompactPair generates CompactPair objects of the correct
+  // types.
+  static_assert(
+      std::is_same_v<decltype(MakeCompactPair(A(0), B(0))), CompactPair<A, B>>,
+      "MakeCompactPair should strip rvalue references");
+  static_assert(
+      std::is_same_v<decltype(MakeCompactPair(a, b)), CompactPair<A, B>>,
+      "MakeCompactPair should strip lvalue references");
+  static_assert(std::is_same_v<decltype(MakeCompactPair(constA, constB)),
+                               CompactPair<A, B>>,
+                "MakeCompactPair should strip CV-qualifiers");
+
+  // Check that copy assignment and move assignment work.
+  a = constA;
+  a = A(0);
+
+  TestInPlaceConstruction();
+
+  return 0;
+}