llvm/unittests/Support/TrailingObjectsTest.cpp

   1 //=== - llvm/unittest/Support/TrailingObjectsTest.cpp ---------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/Support/TrailingObjects.h"
  10 #include "gtest/gtest.h"
  11
  12 using namespace llvm;
  13
  14 namespace {
  15 // This class, beyond being used by the test case, a nice
  16 // demonstration of the intended usage of TrailingObjects, with a
  17 // single trailing array.
  18 class Class1 final : protected TrailingObjects<Class1, short> {
  19   friend TrailingObjects;
  20
  21   unsigned NumShorts;
  22
  23 protected:
  24   size_t numTrailingObjects(OverloadToken<short>) const { return NumShorts; }
  25
  26   Class1(int *ShortArray, unsigned NumShorts) : NumShorts(NumShorts) {
  27     std::uninitialized_copy(ShortArray, ShortArray + NumShorts,
  28                             getTrailingObjects<short>());
  29   }
  30
  31 public:
  32   static Class1 *create(int *ShortArray, unsigned NumShorts) {
  33     void *Mem = ::operator new(totalSizeToAlloc<short>(NumShorts));
  34     return new (Mem) Class1(ShortArray, NumShorts);
  35   }
  36   void operator delete(void *p) { ::operator delete(p); }
  37
  38   short get(unsigned Num) const { return getTrailingObjects<short>()[Num]; }
  39
  40   unsigned numShorts() const { return NumShorts; }
  41
  42   // Pull some protected members in as public, for testability.
  43   template <typename... Ty>
  44   using FixedSizeStorage = TrailingObjects::FixedSizeStorage<Ty...>;
  45
  46   using TrailingObjects::totalSizeToAlloc;
  47   using TrailingObjects::additionalSizeToAlloc;
  48   using TrailingObjects::getTrailingObjects;
  49 };
  50
  51 // Here, there are two singular optional object types appended.  Note
  52 // that the alignment of Class2 is automatically increased to account
  53 // for the alignment requirements of the trailing objects.
  54 class Class2 final : protected TrailingObjects<Class2, double, short> {
  55   friend TrailingObjects;
  56
  57   bool HasShort, HasDouble;
  58
  59 protected:
  60   size_t numTrailingObjects(OverloadToken<short>) const {
  61     return HasShort ? 1 : 0;
  62   }
  63   size_t numTrailingObjects(OverloadToken<double>) const {
  64     return HasDouble ? 1 : 0;
  65   }
  66
  67   Class2(bool HasShort, bool HasDouble)
  68       : HasShort(HasShort), HasDouble(HasDouble) {}
  69
  70 public:
  71   static Class2 *create(short S = 0, double D = 0.0) {
  72     bool HasShort = S != 0;
  73     bool HasDouble = D != 0.0;
  74
  75     void *Mem =
  76         ::operator new(totalSizeToAlloc<double, short>(HasDouble, HasShort));
  77     Class2 *C = new (Mem) Class2(HasShort, HasDouble);
  78     if (HasShort)
  79       *C->getTrailingObjects<short>() = S;
  80     if (HasDouble)
  81       *C->getTrailingObjects<double>() = D;
  82     return C;
  83   }
  84   void operator delete(void *p) { ::operator delete(p); }
  85
  86   short getShort() const {
  87     if (!HasShort)
  88       return 0;
  89     return *getTrailingObjects<short>();
  90   }
  91
  92   double getDouble() const {
  93     if (!HasDouble)
  94       return 0.0;
  95     return *getTrailingObjects<double>();
  96   }
  97
  98   // Pull some protected members in as public, for testability.
  99   template <typename... Ty>
 100   using FixedSizeStorage = TrailingObjects::FixedSizeStorage<Ty...>;
 101
 102   using TrailingObjects::totalSizeToAlloc;
 103   using TrailingObjects::additionalSizeToAlloc;
 104   using TrailingObjects::getTrailingObjects;
 105 };
 106
 107 TEST(TrailingObjects, OneArg) {
 108   int arr[] = {1, 2, 3};
 109   Class1 *C = Class1::create(arr, 3);
 110   EXPECT_EQ(sizeof(Class1), sizeof(unsigned));
 111   EXPECT_EQ(Class1::additionalSizeToAlloc<short>(1), sizeof(short));
 112   EXPECT_EQ(Class1::additionalSizeToAlloc<short>(3), sizeof(short) * 3);
 113
 114   EXPECT_EQ(alignof(Class1),
 115             alignof(Class1::FixedSizeStorage<short>::with_counts<1>::type));
 116   EXPECT_EQ(sizeof(Class1::FixedSizeStorage<short>::with_counts<1>::type),
 117             llvm::alignTo(Class1::totalSizeToAlloc<short>(1), alignof(Class1)));
 118   EXPECT_EQ(Class1::totalSizeToAlloc<short>(1), sizeof(Class1) + sizeof(short));
 119
 120   EXPECT_EQ(alignof(Class1),
 121             alignof(Class1::FixedSizeStorage<short>::with_counts<3>::type));
 122   EXPECT_EQ(sizeof(Class1::FixedSizeStorage<short>::with_counts<3>::type),
 123             llvm::alignTo(Class1::totalSizeToAlloc<short>(3), alignof(Class1)));
 124   EXPECT_EQ(Class1::totalSizeToAlloc<short>(3),
 125             sizeof(Class1) + sizeof(short) * 3);
 126
 127   EXPECT_EQ(C->getTrailingObjects<short>(), reinterpret_cast<short *>(C + 1));
 128   EXPECT_EQ(C->get(0), 1);
 129   EXPECT_EQ(C->get(2), 3);
 130   delete C;
 131 }
 132
 133 TEST(TrailingObjects, TwoArg) {
 134   Class2 *C1 = Class2::create(4);
 135   Class2 *C2 = Class2::create(0, 4.2);
 136
 137   EXPECT_EQ(sizeof(Class2), llvm::alignTo(sizeof(bool) * 2, alignof(double)));
 138   EXPECT_EQ(alignof(Class2), alignof(double));
 139
 140   EXPECT_EQ((Class2::additionalSizeToAlloc<double, short>(1, 0)),
 141             sizeof(double));
 142   EXPECT_EQ((Class2::additionalSizeToAlloc<double, short>(0, 1)),
 143             sizeof(short));
 144   EXPECT_EQ((Class2::additionalSizeToAlloc<double, short>(3, 1)),
 145             sizeof(double) * 3 + sizeof(short));
 146
 147   EXPECT_EQ(
 148       alignof(Class2),
 149       (alignof(
 150           Class2::FixedSizeStorage<double, short>::with_counts<1, 1>::type)));
 151   EXPECT_EQ(
 152       sizeof(Class2::FixedSizeStorage<double, short>::with_counts<1, 1>::type),
 153       llvm::alignTo(Class2::totalSizeToAlloc<double, short>(1, 1),
 154                     alignof(Class2)));
 155   EXPECT_EQ((Class2::totalSizeToAlloc<double, short>(1, 1)),
 156             sizeof(Class2) + sizeof(double) + sizeof(short));
 157
 158   EXPECT_EQ(C1->getDouble(), 0);
 159   EXPECT_EQ(C1->getShort(), 4);
 160   EXPECT_EQ(C1->getTrailingObjects<double>(),
 161             reinterpret_cast<double *>(C1 + 1));
 162   EXPECT_EQ(C1->getTrailingObjects<short>(), reinterpret_cast<short *>(C1 + 1));
 163
 164   EXPECT_EQ(C2->getDouble(), 4.2);
 165   EXPECT_EQ(C2->getShort(), 0);
 166   EXPECT_EQ(C2->getTrailingObjects<double>(),
 167             reinterpret_cast<double *>(C2 + 1));
 168   EXPECT_EQ(C2->getTrailingObjects<short>(),
 169             reinterpret_cast<short *>(reinterpret_cast<double *>(C2 + 1) + 1));
 170   delete C1;
 171   delete C2;
 172 }
 173
 174 // This test class is not trying to be a usage demo, just asserting
 175 // that three args does actually work too (it's the same code as
 176 // handles the second arg, so it's basically covered by the above, but
 177 // just in case..)
 178 class Class3 final : public TrailingObjects<Class3, double, short, bool> {
 179   friend TrailingObjects;
 180
 181   size_t numTrailingObjects(OverloadToken<double>) const { return 1; }
 182   size_t numTrailingObjects(OverloadToken<short>) const { return 1; }
 183 };
 184
 185 TEST(TrailingObjects, ThreeArg) {
 186   EXPECT_EQ((Class3::additionalSizeToAlloc<double, short, bool>(1, 1, 3)),
 187             sizeof(double) + sizeof(short) + 3 * sizeof(bool));
 188   EXPECT_EQ(sizeof(Class3), llvm::alignTo(1, alignof(double)));
 189
 190   EXPECT_EQ(
 191       alignof(Class3),
 192       (alignof(Class3::FixedSizeStorage<double, short,
 193                                         bool>::with_counts<1, 1, 3>::type)));
 194   EXPECT_EQ(
 195       sizeof(Class3::FixedSizeStorage<double, short,
 196                                       bool>::with_counts<1, 1, 3>::type),
 197       llvm::alignTo(Class3::totalSizeToAlloc<double, short, bool>(1, 1, 3),
 198                     alignof(Class3)));
 199
 200   std::unique_ptr<char[]> P(new char[1000]);
 201   Class3 *C = reinterpret_cast<Class3 *>(P.get());
 202   EXPECT_EQ(C->getTrailingObjects<double>(), reinterpret_cast<double *>(C + 1));
 203   EXPECT_EQ(C->getTrailingObjects<short>(),
 204             reinterpret_cast<short *>(reinterpret_cast<double *>(C + 1) + 1));
 205   EXPECT_EQ(
 206       C->getTrailingObjects<bool>(),
 207       reinterpret_cast<bool *>(
 208           reinterpret_cast<short *>(reinterpret_cast<double *>(C + 1) + 1) +
 209           1));
 210 }
 211
 212 class Class4 final : public TrailingObjects<Class4, char, long> {
 213   friend TrailingObjects;
 214   size_t numTrailingObjects(OverloadToken<char>) const { return 1; }
 215 };
 216
 217 TEST(TrailingObjects, Realignment) {
 218   EXPECT_EQ((Class4::additionalSizeToAlloc<char, long>(1, 1)),
 219             llvm::alignTo(sizeof(long) + 1, alignof(long)));
 220   EXPECT_EQ(sizeof(Class4), llvm::alignTo(1, alignof(long)));
 221
 222   EXPECT_EQ(
 223       alignof(Class4),
 224       (alignof(Class4::FixedSizeStorage<char, long>::with_counts<1, 1>::type)));
 225   EXPECT_EQ(
 226       sizeof(Class4::FixedSizeStorage<char, long>::with_counts<1, 1>::type),
 227       llvm::alignTo(Class4::totalSizeToAlloc<char, long>(1, 1),
 228                     alignof(Class4)));
 229
 230   std::unique_ptr<char[]> P(new char[1000]);
 231   Class4 *C = reinterpret_cast<Class4 *>(P.get());
 232   EXPECT_EQ(C->getTrailingObjects<char>(), reinterpret_cast<char *>(C + 1));
 233   EXPECT_EQ(C->getTrailingObjects<long>(),
 234             reinterpret_cast<long *>(llvm::alignAddr(
 235                 reinterpret_cast<char *>(C + 1) + 1, Align::Of<long>())));
 236 }
 237 }
 238
 239 // Test the use of TrailingObjects with a template class. This
 240 // previously failed to compile due to a bug in MSVC's member access
 241 // control/lookup handling for OverloadToken.
 242 template <typename Derived>
 243 class Class5Tmpl : private llvm::TrailingObjects<Derived, float, int> {
 244   using TrailingObjects = typename llvm::TrailingObjects<Derived, float>;
 245   friend TrailingObjects;
 246
 247   size_t numTrailingObjects(
 248       typename TrailingObjects::template OverloadToken<float>) const {
 249     return 1;
 250   }
 251
 252   size_t numTrailingObjects(
 253       typename TrailingObjects::template OverloadToken<int>) const {
 254     return 2;
 255   }
 256 };
 257
 258 class Class5 : public Class5Tmpl<Class5> {};