unittests/ADT/DenseMapTest.cpp

   1 //===- llvm/unittest/ADT/DenseMapMap.cpp - DenseMap unit tests --*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/ADT/DenseMap.h"
  11 #include "gtest/gtest.h"
  12 #include <map>
  13 #include <set>
  14
  15 using namespace llvm;
  16
  17 namespace {
  18
  19 uint32_t getTestKey(int i, uint32_t *) { return i; }
  20 uint32_t getTestValue(int i, uint32_t *) { return 42 + i; }
  21
  22 uint32_t *getTestKey(int i, uint32_t **) {
  23   static uint32_t dummy_arr1[8192];
  24   assert(i < 8192 && "Only support 8192 dummy keys.");
  25   return &dummy_arr1[i];
  26 }
  27 uint32_t *getTestValue(int i, uint32_t **) {
  28   static uint32_t dummy_arr1[8192];
  29   assert(i < 8192 && "Only support 8192 dummy keys.");
  30   return &dummy_arr1[i];
  31 }
  32
  33 /// A test class that tries to check that construction and destruction
  34 /// occur correctly.
  35 class CtorTester {
  36   static std::set<CtorTester *> Constructed;
  37   int Value;
  38
  39 public:
  40   explicit CtorTester(int Value = 0) : Value(Value) {
  41     EXPECT_TRUE(Constructed.insert(this).second);
  42   }
  43   CtorTester(uint32_t Value) : Value(Value) {
  44     EXPECT_TRUE(Constructed.insert(this).second);
  45   }
  46   CtorTester(const CtorTester &Arg) : Value(Arg.Value) {
  47     EXPECT_TRUE(Constructed.insert(this).second);
  48   }
  49   CtorTester &operator=(const CtorTester &) = default;
  50   ~CtorTester() {
  51     EXPECT_EQ(1u, Constructed.erase(this));
  52   }
  53   operator uint32_t() const { return Value; }
  54
  55   int getValue() const { return Value; }
  56   bool operator==(const CtorTester &RHS) const { return Value == RHS.Value; }
  57 };
  58
  59 std::set<CtorTester *> CtorTester::Constructed;
  60
  61 struct CtorTesterMapInfo {
  62   static inline CtorTester getEmptyKey() { return CtorTester(-1); }
  63   static inline CtorTester getTombstoneKey() { return CtorTester(-2); }
  64   static unsigned getHashValue(const CtorTester &Val) {
  65     return Val.getValue() * 37u;
  66   }
  67   static bool isEqual(const CtorTester &LHS, const CtorTester &RHS) {
  68     return LHS == RHS;
  69   }
  70 };
  71
  72 CtorTester getTestKey(int i, CtorTester *) { return CtorTester(i); }
  73 CtorTester getTestValue(int i, CtorTester *) { return CtorTester(42 + i); }
  74
  75 // Test fixture, with helper functions implemented by forwarding to global
  76 // function overloads selected by component types of the type parameter. This
  77 // allows all of the map implementations to be tested with shared
  78 // implementations of helper routines.
  79 template <typename T>
  80 class DenseMapTest : public ::testing::Test {
  81 protected:
  82   T Map;
  83
  84   static typename T::key_type *const dummy_key_ptr;
  85   static typename T::mapped_type *const dummy_value_ptr;
  86
  87   typename T::key_type getKey(int i = 0) {
  88     return getTestKey(i, dummy_key_ptr);
  89   }
  90   typename T::mapped_type getValue(int i = 0) {
  91     return getTestValue(i, dummy_value_ptr);
  92   }
  93 };
  94
  95 template <typename T>
  96 typename T::key_type *const DenseMapTest<T>::dummy_key_ptr = nullptr;
  97 template <typename T>
  98 typename T::mapped_type *const DenseMapTest<T>::dummy_value_ptr = nullptr;
  99
 100 // Register these types for testing.
 101 typedef ::testing::Types<DenseMap<uint32_t, uint32_t>,
 102                          DenseMap<uint32_t *, uint32_t *>,
 103                          DenseMap<CtorTester, CtorTester, CtorTesterMapInfo>,
 104                          SmallDenseMap<uint32_t, uint32_t>,
 105                          SmallDenseMap<uint32_t *, uint32_t *>,
 106                          SmallDenseMap<CtorTester, CtorTester, 4,
 107                                        CtorTesterMapInfo>
 108                          > DenseMapTestTypes;
 109 TYPED_TEST_CASE(DenseMapTest, DenseMapTestTypes);
 110
 111 // Empty map tests
 112 TYPED_TEST(DenseMapTest, EmptyIntMapTest) {
 113   // Size tests
 114   EXPECT_EQ(0u, this->Map.size());
 115   EXPECT_TRUE(this->Map.empty());
 116
 117   // Iterator tests
 118   EXPECT_TRUE(this->Map.begin() == this->Map.end());
 119
 120   // Lookup tests
 121   EXPECT_FALSE(this->Map.count(this->getKey()));
 122   EXPECT_TRUE(this->Map.find(this->getKey()) == this->Map.end());
 123 #if !defined(_MSC_VER) || defined(__clang__)
 124   EXPECT_EQ(typename TypeParam::mapped_type(),
 125             this->Map.lookup(this->getKey()));
 126 #else
 127   // MSVC, at least old versions, cannot parse the typename to disambiguate
 128   // TypeParam::mapped_type as a type. However, because MSVC doesn't implement
 129   // two-phase name lookup, it also doesn't require the typename. Deal with
 130   // this mutual incompatibility through specialized code.
 131   EXPECT_EQ(TypeParam::mapped_type(),
 132             this->Map.lookup(this->getKey()));
 133 #endif
 134 }
 135
 136 // Constant map tests
 137 TYPED_TEST(DenseMapTest, ConstEmptyMapTest) {
 138   const TypeParam &ConstMap = this->Map;
 139   EXPECT_EQ(0u, ConstMap.size());
 140   EXPECT_TRUE(ConstMap.empty());
 141   EXPECT_TRUE(ConstMap.begin() == ConstMap.end());
 142 }
 143
 144 // A map with a single entry
 145 TYPED_TEST(DenseMapTest, SingleEntryMapTest) {
 146   this->Map[this->getKey()] = this->getValue();
 147
 148   // Size tests
 149   EXPECT_EQ(1u, this->Map.size());
 150   EXPECT_FALSE(this->Map.begin() == this->Map.end());
 151   EXPECT_FALSE(this->Map.empty());
 152
 153   // Iterator tests
 154   typename TypeParam::iterator it = this->Map.begin();
 155   EXPECT_EQ(this->getKey(), it->first);
 156   EXPECT_EQ(this->getValue(), it->second);
 157   ++it;
 158   EXPECT_TRUE(it == this->Map.end());
 159
 160   // Lookup tests
 161   EXPECT_TRUE(this->Map.count(this->getKey()));
 162   EXPECT_TRUE(this->Map.find(this->getKey()) == this->Map.begin());
 163   EXPECT_EQ(this->getValue(), this->Map.lookup(this->getKey()));
 164   EXPECT_EQ(this->getValue(), this->Map[this->getKey()]);
 165 }
 166
 167 // Test clear() method
 168 TYPED_TEST(DenseMapTest, ClearTest) {
 169   this->Map[this->getKey()] = this->getValue();
 170   this->Map.clear();
 171
 172   EXPECT_EQ(0u, this->Map.size());
 173   EXPECT_TRUE(this->Map.empty());
 174   EXPECT_TRUE(this->Map.begin() == this->Map.end());
 175 }
 176
 177 // Test erase(iterator) method
 178 TYPED_TEST(DenseMapTest, EraseTest) {
 179   this->Map[this->getKey()] = this->getValue();
 180   this->Map.erase(this->Map.begin());
 181
 182   EXPECT_EQ(0u, this->Map.size());
 183   EXPECT_TRUE(this->Map.empty());
 184   EXPECT_TRUE(this->Map.begin() == this->Map.end());
 185 }
 186
 187 // Test erase(value) method
 188 TYPED_TEST(DenseMapTest, EraseTest2) {
 189   this->Map[this->getKey()] = this->getValue();
 190   this->Map.erase(this->getKey());
 191
 192   EXPECT_EQ(0u, this->Map.size());
 193   EXPECT_TRUE(this->Map.empty());
 194   EXPECT_TRUE(this->Map.begin() == this->Map.end());
 195 }
 196
 197 // Test insert() method
 198 TYPED_TEST(DenseMapTest, InsertTest) {
 199   this->Map.insert(std::make_pair(this->getKey(), this->getValue()));
 200   EXPECT_EQ(1u, this->Map.size());
 201   EXPECT_EQ(this->getValue(), this->Map[this->getKey()]);
 202 }
 203
 204 // Test copy constructor method
 205 TYPED_TEST(DenseMapTest, CopyConstructorTest) {
 206   this->Map[this->getKey()] = this->getValue();
 207   TypeParam copyMap(this->Map);
 208
 209   EXPECT_EQ(1u, copyMap.size());
 210   EXPECT_EQ(this->getValue(), copyMap[this->getKey()]);
 211 }
 212
 213 // Test copy constructor method where SmallDenseMap isn't small.
 214 TYPED_TEST(DenseMapTest, CopyConstructorNotSmallTest) {
 215   for (int Key = 0; Key < 5; ++Key)
 216     this->Map[this->getKey(Key)] = this->getValue(Key);
 217   TypeParam copyMap(this->Map);
 218
 219   EXPECT_EQ(5u, copyMap.size());
 220   for (int Key = 0; Key < 5; ++Key)
 221     EXPECT_EQ(this->getValue(Key), copyMap[this->getKey(Key)]);
 222 }
 223
 224 // Test copying from a default-constructed map.
 225 TYPED_TEST(DenseMapTest, CopyConstructorFromDefaultTest) {
 226   TypeParam copyMap(this->Map);
 227
 228   EXPECT_TRUE(copyMap.empty());
 229 }
 230
 231 // Test copying from an empty map where SmallDenseMap isn't small.
 232 TYPED_TEST(DenseMapTest, CopyConstructorFromEmptyTest) {
 233   for (int Key = 0; Key < 5; ++Key)
 234     this->Map[this->getKey(Key)] = this->getValue(Key);
 235   this->Map.clear();
 236   TypeParam copyMap(this->Map);
 237
 238   EXPECT_TRUE(copyMap.empty());
 239 }
 240
 241 // Test assignment operator method
 242 TYPED_TEST(DenseMapTest, AssignmentTest) {
 243   this->Map[this->getKey()] = this->getValue();
 244   TypeParam copyMap = this->Map;
 245
 246   EXPECT_EQ(1u, copyMap.size());
 247   EXPECT_EQ(this->getValue(), copyMap[this->getKey()]);
 248
 249   // test self-assignment.
 250   copyMap = static_cast<TypeParam &>(copyMap);
 251   EXPECT_EQ(1u, copyMap.size());
 252   EXPECT_EQ(this->getValue(), copyMap[this->getKey()]);
 253 }
 254
 255 TYPED_TEST(DenseMapTest, AssignmentTestNotSmall) {
 256   for (int Key = 0; Key < 5; ++Key)
 257     this->Map[this->getKey(Key)] = this->getValue(Key);
 258   TypeParam copyMap = this->Map;
 259
 260   EXPECT_EQ(5u, copyMap.size());
 261   for (int Key = 0; Key < 5; ++Key)
 262     EXPECT_EQ(this->getValue(Key), copyMap[this->getKey(Key)]);
 263
 264   // test self-assignment.
 265   copyMap = static_cast<TypeParam &>(copyMap);
 266   EXPECT_EQ(5u, copyMap.size());
 267   for (int Key = 0; Key < 5; ++Key)
 268     EXPECT_EQ(this->getValue(Key), copyMap[this->getKey(Key)]);
 269 }
 270
 271 // Test swap method
 272 TYPED_TEST(DenseMapTest, SwapTest) {
 273   this->Map[this->getKey()] = this->getValue();
 274   TypeParam otherMap;
 275
 276   this->Map.swap(otherMap);
 277   EXPECT_EQ(0u, this->Map.size());
 278   EXPECT_TRUE(this->Map.empty());
 279   EXPECT_EQ(1u, otherMap.size());
 280   EXPECT_EQ(this->getValue(), otherMap[this->getKey()]);
 281
 282   this->Map.swap(otherMap);
 283   EXPECT_EQ(0u, otherMap.size());
 284   EXPECT_TRUE(otherMap.empty());
 285   EXPECT_EQ(1u, this->Map.size());
 286   EXPECT_EQ(this->getValue(), this->Map[this->getKey()]);
 287
 288   // Make this more interesting by inserting 100 numbers into the map.
 289   for (int i = 0; i < 100; ++i)
 290     this->Map[this->getKey(i)] = this->getValue(i);
 291
 292   this->Map.swap(otherMap);
 293   EXPECT_EQ(0u, this->Map.size());
 294   EXPECT_TRUE(this->Map.empty());
 295   EXPECT_EQ(100u, otherMap.size());
 296   for (int i = 0; i < 100; ++i)
 297     EXPECT_EQ(this->getValue(i), otherMap[this->getKey(i)]);
 298
 299   this->Map.swap(otherMap);
 300   EXPECT_EQ(0u, otherMap.size());
 301   EXPECT_TRUE(otherMap.empty());
 302   EXPECT_EQ(100u, this->Map.size());
 303   for (int i = 0; i < 100; ++i)
 304     EXPECT_EQ(this->getValue(i), this->Map[this->getKey(i)]);
 305 }
 306
 307 // A more complex iteration test
 308 TYPED_TEST(DenseMapTest, IterationTest) {
 309   bool visited[100];
 310   std::map<typename TypeParam::key_type, unsigned> visitedIndex;
 311
 312   // Insert 100 numbers into the map
 313   for (int i = 0; i < 100; ++i) {
 314     visited[i] = false;
 315     visitedIndex[this->getKey(i)] = i;
 316
 317     this->Map[this->getKey(i)] = this->getValue(i);
 318   }
 319
 320   // Iterate over all numbers and mark each one found.
 321   for (typename TypeParam::iterator it = this->Map.begin();
 322        it != this->Map.end(); ++it)
 323     visited[visitedIndex[it->first]] = true;
 324
 325   // Ensure every number was visited.
 326   for (int i = 0; i < 100; ++i)
 327     ASSERT_TRUE(visited[i]) << "Entry #" << i << " was never visited";
 328 }
 329
 330 // const_iterator test
 331 TYPED_TEST(DenseMapTest, ConstIteratorTest) {
 332   // Check conversion from iterator to const_iterator.
 333   typename TypeParam::iterator it = this->Map.begin();
 334   typename TypeParam::const_iterator cit(it);
 335   EXPECT_TRUE(it == cit);
 336
 337   // Check copying of const_iterators.
 338   typename TypeParam::const_iterator cit2(cit);
 339   EXPECT_TRUE(cit == cit2);
 340 }
 341
 342 namespace {
 343 // Simple class that counts how many moves and copy happens when growing a map
 344 struct CountCopyAndMove {
 345   static int Move;
 346   static int Copy;
 347   CountCopyAndMove() {}
 348
 349   CountCopyAndMove(const CountCopyAndMove &) { Copy++; }
 350   CountCopyAndMove &operator=(const CountCopyAndMove &) {
 351     Copy++;
 352     return *this;
 353   }
 354   CountCopyAndMove(CountCopyAndMove &&) { Move++; }
 355   CountCopyAndMove &operator=(const CountCopyAndMove &&) {
 356     Move++;
 357     return *this;
 358   }
 359 };
 360 int CountCopyAndMove::Copy = 0;
 361 int CountCopyAndMove::Move = 0;
 362
 363 } // anonymous namespace
 364
 365 // Test for the default minimum size of a DenseMap
 366 TEST(DenseMapCustomTest, DefaultMinReservedSizeTest) {
 367   // IF THIS VALUE CHANGE, please update InitialSizeTest, InitFromIterator, and
 368   // ReserveTest as well!
 369   const int ExpectedInitialBucketCount = 64;
 370   // Formula from DenseMap::getMinBucketToReserveForEntries()
 371   const int ExpectedMaxInitialEntries = ExpectedInitialBucketCount * 3 / 4 - 1;
 372
 373   DenseMap<int, CountCopyAndMove> Map;
 374   // Will allocate 64 buckets
 375   Map.reserve(1);
 376   unsigned MemorySize = Map.getMemorySize();
 377   CountCopyAndMove::Copy = 0;
 378   CountCopyAndMove::Move = 0;
 379   for (int i = 0; i < ExpectedMaxInitialEntries; ++i)
 380     Map.insert(std::pair<int, CountCopyAndMove>(std::piecewise_construct,
 381                                                 std::forward_as_tuple(i),
 382                                                 std::forward_as_tuple()));
 383   // Check that we didn't grow
 384   EXPECT_EQ(MemorySize, Map.getMemorySize());
 385   // Check that move was called the expected number of times
 386   EXPECT_EQ(ExpectedMaxInitialEntries, CountCopyAndMove::Move);
 387   // Check that no copy occurred
 388   EXPECT_EQ(0, CountCopyAndMove::Copy);
 389
 390   // Adding one extra element should grow the map
 391   Map.insert(std::pair<int, CountCopyAndMove>(
 392       std::piecewise_construct,
 393       std::forward_as_tuple(ExpectedMaxInitialEntries),
 394       std::forward_as_tuple()));
 395   // Check that we grew
 396   EXPECT_NE(MemorySize, Map.getMemorySize());
 397   // Check that move was called the expected number of times
 398   //  This relies on move-construction elision, and cannot be reliably tested.
 399   //   EXPECT_EQ(ExpectedMaxInitialEntries + 2, CountCopyAndMove::Move);
 400   // Check that no copy occurred
 401   EXPECT_EQ(0, CountCopyAndMove::Copy);
 402 }
 403
 404 // Make sure creating the map with an initial size of N actually gives us enough
 405 // buckets to insert N items without increasing allocation size.
 406 TEST(DenseMapCustomTest, InitialSizeTest) {
 407   // Test a few different sizes, 48 is *not* a random choice: we need a value
 408   // that is 2/3 of a power of two to stress the grow() condition, and the power
 409   // of two has to be at least 64 because of minimum size allocation in the
 410   // DenseMap (see DefaultMinReservedSizeTest). 66 is a value just above the
 411   // 64 default init.
 412   for (auto Size : {1, 2, 48, 66}) {
 413     DenseMap<int, CountCopyAndMove> Map(Size);
 414     unsigned MemorySize = Map.getMemorySize();
 415     CountCopyAndMove::Copy = 0;
 416     CountCopyAndMove::Move = 0;
 417     for (int i = 0; i < Size; ++i)
 418       Map.insert(std::pair<int, CountCopyAndMove>(std::piecewise_construct,
 419                                                   std::forward_as_tuple(i),
 420                                                   std::forward_as_tuple()));
 421     // Check that we didn't grow
 422     EXPECT_EQ(MemorySize, Map.getMemorySize());
 423     // Check that move was called the expected number of times
 424     EXPECT_EQ(Size, CountCopyAndMove::Move);
 425     // Check that no copy occurred
 426     EXPECT_EQ(0, CountCopyAndMove::Copy);
 427   }
 428 }
 429
 430 // Make sure creating the map with a iterator range does not trigger grow()
 431 TEST(DenseMapCustomTest, InitFromIterator) {
 432   std::vector<std::pair<int, CountCopyAndMove>> Values;
 433   // The size is a random value greater than 64 (hardcoded DenseMap min init)
 434   const int Count = 65;
 435   for (int i = 0; i < Count; i++)
 436     Values.emplace_back(i, CountCopyAndMove());
 437
 438   CountCopyAndMove::Move = 0;
 439   CountCopyAndMove::Copy = 0;
 440   DenseMap<int, CountCopyAndMove> Map(Values.begin(), Values.end());
 441   // Check that no move occurred
 442   EXPECT_EQ(0, CountCopyAndMove::Move);
 443   // Check that copy was called the expected number of times
 444   EXPECT_EQ(Count, CountCopyAndMove::Copy);
 445 }
 446
 447 // Make sure reserve actually gives us enough buckets to insert N items
 448 // without increasing allocation size.
 449 TEST(DenseMapCustomTest, ReserveTest) {
 450   // Test a few different size, 48 is *not* a random choice: we need a value
 451   // that is 2/3 of a power of two to stress the grow() condition, and the power
 452   // of two has to be at least 64 because of minimum size allocation in the
 453   // DenseMap (see DefaultMinReservedSizeTest). 66 is a value just above the
 454   // 64 default init.
 455   for (auto Size : {1, 2, 48, 66}) {
 456     DenseMap<int, CountCopyAndMove> Map;
 457     Map.reserve(Size);
 458     unsigned MemorySize = Map.getMemorySize();
 459     CountCopyAndMove::Copy = 0;
 460     CountCopyAndMove::Move = 0;
 461     for (int i = 0; i < Size; ++i)
 462       Map.insert(std::pair<int, CountCopyAndMove>(std::piecewise_construct,
 463                                                   std::forward_as_tuple(i),
 464                                                   std::forward_as_tuple()));
 465     // Check that we didn't grow
 466     EXPECT_EQ(MemorySize, Map.getMemorySize());
 467     // Check that move was called the expected number of times
 468     EXPECT_EQ(Size, CountCopyAndMove::Move);
 469     // Check that no copy occurred
 470     EXPECT_EQ(0, CountCopyAndMove::Copy);
 471   }
 472 }
 473
 474 // Make sure DenseMap works with StringRef keys.
 475 TEST(DenseMapCustomTest, StringRefTest) {
 476   DenseMap<StringRef, int> M;
 477
 478   M["a"] = 1;
 479   M["b"] = 2;
 480   M["c"] = 3;
 481
 482   EXPECT_EQ(3u, M.size());
 483   EXPECT_EQ(1, M.lookup("a"));
 484   EXPECT_EQ(2, M.lookup("b"));
 485   EXPECT_EQ(3, M.lookup("c"));
 486
 487   EXPECT_EQ(0, M.lookup("q"));
 488
 489   // Test the empty string, spelled various ways.
 490   EXPECT_EQ(0, M.lookup(""));
 491   EXPECT_EQ(0, M.lookup(StringRef()));
 492   EXPECT_EQ(0, M.lookup(StringRef("a", 0)));
 493   M[""] = 42;
 494   EXPECT_EQ(42, M.lookup(""));
 495   EXPECT_EQ(42, M.lookup(StringRef()));
 496   EXPECT_EQ(42, M.lookup(StringRef("a", 0)));
 497 }
 498
 499 // Key traits that allows lookup with either an unsigned or char* key;
 500 // In the latter case, "a" == 0, "b" == 1 and so on.
 501 struct TestDenseMapInfo {
 502   static inline unsigned getEmptyKey() { return ~0; }
 503   static inline unsigned getTombstoneKey() { return ~0U - 1; }
 504   static unsigned getHashValue(const unsigned& Val) { return Val * 37U; }
 505   static unsigned getHashValue(const char* Val) {
 506     return (unsigned)(Val[0] - 'a') * 37U;
 507   }
 508   static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
 509     return LHS == RHS;
 510   }
 511   static bool isEqual(const char* LHS, const unsigned& RHS) {
 512     return (unsigned)(LHS[0] - 'a') == RHS;
 513   }
 514 };
 515
 516 // find_as() tests
 517 TEST(DenseMapCustomTest, FindAsTest) {
 518   DenseMap<unsigned, unsigned, TestDenseMapInfo> map;
 519   map[0] = 1;
 520   map[1] = 2;
 521   map[2] = 3;
 522
 523   // Size tests
 524   EXPECT_EQ(3u, map.size());
 525
 526   // Normal lookup tests
 527   EXPECT_EQ(1u, map.count(1));
 528   EXPECT_EQ(1u, map.find(0)->second);
 529   EXPECT_EQ(2u, map.find(1)->second);
 530   EXPECT_EQ(3u, map.find(2)->second);
 531   EXPECT_TRUE(map.find(3) == map.end());
 532
 533   // find_as() tests
 534   EXPECT_EQ(1u, map.find_as("a")->second);
 535   EXPECT_EQ(2u, map.find_as("b")->second);
 536   EXPECT_EQ(3u, map.find_as("c")->second);
 537   EXPECT_TRUE(map.find_as("d") == map.end());
 538 }
 539
 540 struct ContiguousDenseMapInfo {
 541   static inline unsigned getEmptyKey() { return ~0; }
 542   static inline unsigned getTombstoneKey() { return ~0U - 1; }
 543   static unsigned getHashValue(const unsigned& Val) { return Val; }
 544   static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
 545     return LHS == RHS;
 546   }
 547 };
 548
 549 // Test that filling a small dense map with exactly the number of elements in
 550 // the map grows to have enough space for an empty bucket.
 551 TEST(DenseMapCustomTest, SmallDenseMapGrowTest) {
 552   SmallDenseMap<unsigned, unsigned, 32, ContiguousDenseMapInfo> map;
 553   // Add some number of elements, then delete a few to leave us some tombstones.
 554   // If we just filled the map with 32 elements we'd grow because of not enough
 555   // tombstones which masks the issue here.
 556   for (unsigned i = 0; i < 20; ++i)
 557     map[i] = i + 1;
 558   for (unsigned i = 0; i < 10; ++i)
 559     map.erase(i);
 560   for (unsigned i = 20; i < 32; ++i)
 561     map[i] = i + 1;
 562
 563   // Size tests
 564   EXPECT_EQ(22u, map.size());
 565
 566   // Try to find an element which doesn't exist.  There was a bug in
 567   // SmallDenseMap which led to a map with num elements == small capacity not
 568   // having an empty bucket any more.  Finding an element not in the map would
 569   // therefore never terminate.
 570   EXPECT_TRUE(map.find(32) == map.end());
 571 }
 572
 573 TEST(DenseMapCustomTest, TryEmplaceTest) {
 574   DenseMap<int, std::unique_ptr<int>> Map;
 575   std::unique_ptr<int> P(new int(2));
 576   auto Try1 = Map.try_emplace(0, new int(1));
 577   EXPECT_TRUE(Try1.second);
 578   auto Try2 = Map.try_emplace(0, std::move(P));
 579   EXPECT_FALSE(Try2.second);
 580   EXPECT_EQ(Try1.first, Try2.first);
 581   EXPECT_NE(nullptr, P);
 582 }
 583
 584 TEST(DenseMapCustomTest, ConstTest) {
 585   // Test that const pointers work okay for count and find, even when the
 586   // underlying map is a non-const pointer.
 587   DenseMap<int *, int> Map;
 588   int A;
 589   int *B = &A;
 590   const int *C = &A;
 591   Map.insert({B, 0});
 592   EXPECT_EQ(Map.count(B), 1u);
 593   EXPECT_EQ(Map.count(C), 1u);
 594   EXPECT_NE(Map.find(B), Map.end());
 595   EXPECT_NE(Map.find(C), Map.end());
 596 }
 597 }