// Copyright (c) 2010 Google Inc.
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//
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// static_range_map_unittest.cc: Unit tests for StaticRangeMap.
//
// Author: Siyang Xie (lambxsy@google.com)

#include "breakpad_googletest_includes.h"
#include "common/scoped_ptr.h"
#include "processor/range_map-inl.h"
#include "processor/static_range_map-inl.h"
#include "processor/simple_serializer-inl.h"
#include "processor/map_serializers-inl.h"
#include "processor/logging.h"


namespace {
// Types used for testing.
typedef int AddressType;
typedef int EntryType;
typedef google_breakpad::StaticRangeMap< AddressType, EntryType > TestMap;
typedef google_breakpad::RangeMap< AddressType, EntryType > RMap;

// RangeTest contains data to use for store and retrieve tests.  See
// RunTests for descriptions of the tests.
struct RangeTest {
  // Base address to use for test
  AddressType address;

  // Size of range to use for test
  AddressType size;

  // Unique ID of range - unstorable ranges must have unique IDs too
  EntryType id;

  // Whether this range is expected to be stored successfully or not
  bool expect_storable;
};

// A RangeTestSet encompasses multiple RangeTests, which are run in
// sequence on the same RangeMap.
struct RangeTestSet {
  // An array of RangeTests
  const RangeTest* range_tests;

  // The number of tests in the set
  unsigned int range_test_count;
};

// These tests will be run sequentially.  The first set of tests exercises
// most functions of RangeTest, and verifies all of the bounds-checking.
const RangeTest range_tests_0[] = {
  { INT_MIN,     16,      1,  true },   // lowest possible range
  { -2,          5,       2,  true },   // a range through zero
  { INT_MAX - 9, 11,      3,  false },  // tests anti-overflow
  { INT_MAX - 9, 10,      4,  true },   // highest possible range
  { 5,           0,       5,  false },  // tests anti-zero-size
  { 5,           1,       6,  true },   // smallest possible range
  { -20,         15,      7,  true },   // entirely negative

  { 10,          10,      10, true },   // causes the following tests to fail
  { 9,           10,      11, false },  // one-less base, one-less high
  { 9,           11,      12, false },  // one-less base, identical high
  { 9,           12,      13, false },  // completely contains existing
  { 10,          9,       14, false },  // identical base, one-less high
  { 10,          10,      15, false },  // exactly identical to existing range
  { 10,          11,      16, false },  // identical base, one-greater high
  { 11,          8,       17, false },  // contained completely within
  { 11,          9,       18, false },  // one-greater base, identical high
  { 11,          10,      19, false },  // one-greater base, one-greater high
  { 9,           2,       20, false },  // overlaps bottom by one
  { 10,          1,       21, false },  // overlaps bottom by one, contained
  { 19,          1,       22, false },  // overlaps top by one, contained
  { 19,          2,       23, false },  // overlaps top by one

  { 9,           1,       24, true },   // directly below without overlap
  { 20,          1,       25, true },   // directly above without overlap

  { 6,           3,       26, true },   // exactly between two ranges, gapless
  { 7,           3,       27, false },  // tries to span two ranges
  { 7,           5,       28, false },  // tries to span three ranges
  { 4,           20,      29, false },  // tries to contain several ranges

  { 30,          50,      30, true },
  { 90,          25,      31, true },
  { 35,          65,      32, false },  // tries to span two noncontiguous
  { 120,         10000,   33, true },   // > 8-bit
  { 20000,       20000,   34, true },   // > 8-bit
  { 0x10001,     0x10001, 35, true },   // > 16-bit

  { 27,          -1,      36, false }   // tests high < base
};

// Attempt to fill the entire space.  The entire space must be filled with
// three stores because AddressType is signed for these tests, so RangeMap
// treats the size as signed and rejects sizes that appear to be negative.
// Even if these tests were run as unsigned, two stores would be needed
// to fill the space because the entire size of the space could only be
// described by using one more bit than would be present in AddressType.
const RangeTest range_tests_1[] = {
  { INT_MIN, INT_MAX, 50, true },   // From INT_MIN to -2, inclusive
  { -1,      2,       51, true },   // From -1 to 0, inclusive
  { 1,       INT_MAX, 52, true },   // From 1 to INT_MAX, inclusive
  { INT_MIN, INT_MAX, 53, false },  // Can't fill the space twice
  { -1,      2,       54, false },
  { 1,       INT_MAX, 55, false },
  { -3,      6,       56, false },  // -3 to 2, inclusive - spans 3 ranges
};

// A light round of testing to verify that RetrieveRange does the right
// the right thing at the extremities of the range when nothing is stored
// there.  Checks are forced without storing anything at the extremities
// by setting size = 0.
const RangeTest range_tests_2[] = {
  { INT_MIN, 0, 100, false },  // makes RetrieveRange check low end
  { -1,      3, 101, true },
  { INT_MAX, 0, 102, false },  // makes RetrieveRange check high end
};

// Similar to the previous test set, but with a couple of ranges closer
// to the extremities.
const RangeTest range_tests_3[] = {
  { INT_MIN + 1, 1, 110, true },
  { INT_MAX - 1, 1, 111, true },
  { INT_MIN,     0, 112, false },  // makes RetrieveRange check low end
  { INT_MAX,     0, 113, false }   // makes RetrieveRange check high end
};

// The range map is cleared between sets of tests listed here.
const RangeTestSet range_test_sets[] = {
  { range_tests_0, sizeof(range_tests_0) / sizeof(RangeTest) },
  { range_tests_1, sizeof(range_tests_1) / sizeof(RangeTest) },
  { range_tests_2, sizeof(range_tests_2) / sizeof(RangeTest) },
  { range_tests_3, sizeof(range_tests_3) / sizeof(RangeTest) },
  { range_tests_0, sizeof(range_tests_0) / sizeof(RangeTest) }   // Run again
};

}  // namespace

namespace google_breakpad {
class TestStaticRangeMap : public ::testing::Test {
 protected:
  void SetUp() {
    kTestCasesCount_ = sizeof(range_test_sets) / sizeof(RangeTestSet);
  }

  // StoreTest uses the data in a RangeTest and calls StoreRange on the
  // test RangeMap.  It returns true if the expected result occurred, and
  // false if something else happened.
  void StoreTest(RMap* range_map, const RangeTest* range_test);

  // RetrieveTest uses the data in RangeTest and calls RetrieveRange on the
  // test RangeMap.  If it retrieves the expected value (which can be no
  // map entry at the specified range,) it returns true, otherwise, it returns
  // false.  RetrieveTest will check the values around the base address and
  // the high address of a range to guard against off-by-one errors.
  void RetrieveTest(TestMap* range_map, const RangeTest* range_test);

  // Test RetrieveRangeAtIndex, which is supposed to return objects in order
  // according to their addresses.  This test is performed by looping through
  // the map, calling RetrieveRangeAtIndex for all possible indices in sequence,
  // and verifying that each call returns a different object than the previous
  // call, and that ranges are returned with increasing base addresses.  Returns
  // false if the test fails.
  void RetrieveIndexTest(const TestMap* range_map, int set);

  void RunTestCase(int test_case);

  unsigned int kTestCasesCount_;
  RangeMapSerializer<AddressType, EntryType> serializer_;
};

void TestStaticRangeMap::StoreTest(RMap* range_map,
                                   const RangeTest* range_test) {
  bool stored = range_map->StoreRange(range_test->address,
                                      range_test->size,
                                      range_test->id);
  EXPECT_EQ(stored, range_test->expect_storable)
      << "StoreRange id " << range_test->id << "FAILED";
}

void TestStaticRangeMap::RetrieveTest(TestMap* range_map,
                                      const RangeTest* range_test) {
  for (unsigned int side = 0; side <= 1; ++side) {
    // When side == 0, check the low side (base address) of each range.
    // When side == 1, check the high side (base + size) of each range.

    // Check one-less and one-greater than the target address in addition
    // to the target address itself.

    // If the size of the range is only 1, don't check one greater than
    // the base or one less than the high - for a successfully stored
    // range, these tests would erroneously fail because the range is too
    // small.
    AddressType low_offset = -1;
    AddressType high_offset = 1;
    if (range_test->size == 1) {
      if (!side)          // When checking the low side,
        high_offset = 0;  // don't check one over the target.
      else                // When checking the high side,
        low_offset = 0;   // don't check one under the target.
    }

    for (AddressType offset = low_offset; offset <= high_offset; ++offset) {
      AddressType address =
          offset +
          (!side ? range_test->address :
                   range_test->address + range_test->size - 1);

      bool expected_result = false;  // This is correct for tests not stored.
      if (range_test->expect_storable) {
        if (offset == 0)             // When checking the target address,
          expected_result = true;    // test should always succeed.
        else if (offset == -1)       // When checking one below the target,
          expected_result = side;    // should fail low and succeed high.
        else                         // When checking one above the target,
          expected_result = !side;   // should succeed low and fail high.
      }

      const EntryType* id;
      AddressType retrieved_base;
      AddressType retrieved_size;
      bool retrieved = range_map->RetrieveRange(address, id,
                                                &retrieved_base,
                                                &retrieved_size);

      bool observed_result = retrieved && *id == range_test->id;
      EXPECT_EQ(observed_result, expected_result)
          << "RetrieveRange id " << range_test->id
          << ", side " << side << ", offset " << offset << " FAILED.";

      // If a range was successfully retrieved, check that the returned
      // bounds match the range as stored.
      if (observed_result == true) {
        EXPECT_EQ(retrieved_base, range_test->address)
            << "RetrieveRange id " << range_test->id
            << ", side " << side << ", offset " << offset << " FAILED.";
        EXPECT_EQ(retrieved_size, range_test->size)
            << "RetrieveRange id " << range_test->id
            << ", side " << side << ", offset " << offset << " FAILED.";
      }

      // Now, check RetrieveNearestRange.  The nearest range is always
      // expected to be different from the test range when checking one
      // less than the low side.
      bool expected_nearest = range_test->expect_storable;
      if (!side && offset < 0)
        expected_nearest = false;

      AddressType nearest_base;
      AddressType nearest_size;
      bool retrieved_nearest = range_map->RetrieveNearestRange(address,
                                                               id,
                                                               &nearest_base,
                                                               &nearest_size);

      // When checking one greater than the high side, RetrieveNearestRange
      // should usually return the test range.  When a different range begins
      // at that address, though, then RetrieveNearestRange should return the
      // range at the address instead of the test range.
      if (side && offset > 0 && nearest_base == address) {
        expected_nearest = false;
      }

      bool observed_nearest = retrieved_nearest &&
                              *id == range_test->id;

      EXPECT_EQ(observed_nearest, expected_nearest)
          << "RetrieveRange id " << range_test->id
          << ", side " << side << ", offset " << offset << " FAILED.";

      // If a range was successfully retrieved, check that the returned
      // bounds match the range as stored.
      if (expected_nearest ==true) {
        EXPECT_EQ(nearest_base, range_test->address)
            << "RetrieveRange id " << range_test->id
            << ", side " << side << ", offset " << offset << " FAILED.";
        EXPECT_EQ(nearest_size, range_test->size)
            << "RetrieveRange id " << range_test->id
            << ", side " << side << ", offset " << offset << " FAILED.";
      }
    }
  }
}

void TestStaticRangeMap::RetrieveIndexTest(const TestMap* range_map, int set) {
  AddressType last_base = 0;
  const EntryType* last_entry = 0;
  const EntryType* entry;
  int object_count = range_map->GetCount();
  for (int object_index = 0; object_index < object_count; ++object_index) {
    AddressType base;
    ASSERT_TRUE(range_map->RetrieveRangeAtIndex(object_index,
                                                entry,
                                                &base,
                                                NULL))
        << "FAILED: RetrieveRangeAtIndex set " << set
        << " index " << object_index;

    ASSERT_TRUE(entry) << "FAILED: RetrieveRangeAtIndex set " << set
                           << " index " << object_index;

    // It's impossible to do these comparisons unless there's a previous
    // object to compare against.
    if (last_entry) {
      // The object must be different from the last_entry one.
      EXPECT_NE(*entry, *last_entry) << "FAILED: RetrieveRangeAtIndex set "
                                     << set << " index " << object_index;
      // Each object must have a base greater than the previous object's base.
      EXPECT_GT(base, last_base) << "FAILED: RetrieveRangeAtIndex set " << set
                                 << " index " << object_index;
    }
    last_entry = entry;
    last_base = base;
  }

  // Make sure that RetrieveRangeAtIndex doesn't allow lookups at indices that
  // are too high.
  ASSERT_FALSE(range_map->RetrieveRangeAtIndex(
      object_count, entry, NULL, NULL)) << "FAILED: RetrieveRangeAtIndex set "
                                        << set << " index " << object_count
                                        << " (too large)";
}

// RunTests runs a series of test sets.
void TestStaticRangeMap::RunTestCase(int test_case) {
  // Maintain the range map in a pointer so that deletion can be meaningfully
  // tested.
  scoped_ptr<RMap> rmap(new RMap());

  const RangeTest* range_tests = range_test_sets[test_case].range_tests;
  unsigned int range_test_count = range_test_sets[test_case].range_test_count;

  // Run the StoreRange test, which validates StoreRange and initializes
  // the RangeMap with data for the RetrieveRange test.
  int stored_count = 0;  // The number of ranges successfully stored
  for (unsigned int range_test_index = 0;
       range_test_index < range_test_count;
       ++range_test_index) {
    const RangeTest* range_test = &range_tests[range_test_index];
    StoreTest(rmap.get(), range_test);

    if (range_test->expect_storable)
      ++stored_count;
  }

  scoped_array<char> memaddr(serializer_.Serialize(*rmap, NULL));
  scoped_ptr<TestMap> static_range_map(new TestMap(memaddr.get()));

  // The RangeMap's own count of objects should also match.
  EXPECT_EQ(static_range_map->GetCount(), stored_count);

  // Run the RetrieveRange test
  for (unsigned int range_test_index = 0;
       range_test_index < range_test_count;
       ++range_test_index) {
    const RangeTest* range_test = &range_tests[range_test_index];
    RetrieveTest(static_range_map.get(), range_test);
  }

  RetrieveIndexTest(static_range_map.get(), test_case);
}

TEST_F(TestStaticRangeMap, TestCase0) {
  int test_case = 0;
  RunTestCase(test_case);
}

TEST_F(TestStaticRangeMap, TestCase1) {
  int test_case = 1;
  RunTestCase(test_case);
}

TEST_F(TestStaticRangeMap, TestCase2) {
  int test_case = 2;
  RunTestCase(test_case);
}

TEST_F(TestStaticRangeMap, TestCase3) {
  int test_case = 3;
  RunTestCase(test_case);
}

TEST_F(TestStaticRangeMap, RunTestCase0Again) {
  int test_case = 0;
  RunTestCase(test_case);
}

}  // namespace google_breakpad

int main(int argc, char *argv[]) {
  ::testing::InitGoogleTest(&argc, argv);

  return RUN_ALL_TESTS();
}