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28  
29  // safe_math_unittest.cc: Unit tests for SafeMath
30  
31  #ifdef HAVE_CONFIG_H
32  #include <config.h>  // Must come first
33  #endif
34  
35  #include "safe_math.h"
36  #include "breakpad_googletest_includes.h"
37  
38  namespace {
39  
40  using google_breakpad::AddIgnoringOverflow;
41  using google_breakpad::AddWithOverflowCheck;
42  
43  TEST(SafeMath, AddOverflowWorksAsIntended) {
44    EXPECT_EQ(AddWithOverflowCheck<uint8_t>(0, 0),
45              std::make_pair<uint8_t>(0, false));
46    EXPECT_EQ(AddWithOverflowCheck<uint8_t>(0, 255),
47              std::make_pair<uint8_t>(255, false));
48    EXPECT_EQ(AddWithOverflowCheck<uint8_t>(1, 255),
49              std::make_pair<uint8_t>(0, true));
50  
51    EXPECT_EQ(AddWithOverflowCheck<int8_t>(-128, 127),
52              std::make_pair<int8_t>(-1, false));
53    EXPECT_EQ(AddWithOverflowCheck<int8_t>(127, -128),
54              std::make_pair<int8_t>(-1, false));
55    EXPECT_EQ(AddWithOverflowCheck<int8_t>(1, -128),
56              std::make_pair<int8_t>(-127, false));
57    EXPECT_EQ(AddWithOverflowCheck<int8_t>(127, -1),
58              std::make_pair<int8_t>(126, false));
59  
60    EXPECT_EQ(AddWithOverflowCheck<int8_t>(-128, -1),
61              std::make_pair<int8_t>(127, true));
62    EXPECT_EQ(AddWithOverflowCheck<int8_t>(-128, -128),
63              std::make_pair<int8_t>(0, true));
64    EXPECT_EQ(AddWithOverflowCheck<int8_t>(127, 1),
65              std::make_pair<int8_t>(-128, true));
66    EXPECT_EQ(AddWithOverflowCheck<int8_t>(127, 127),
67              std::make_pair<int8_t>(-2, true));
68  }
69  
70  TEST(SafeMath, AddIgnoringOverflowWorksAsIntended) {
71    EXPECT_EQ(AddIgnoringOverflow<uint8_t>(0, 0), 0);
72    EXPECT_EQ(AddIgnoringOverflow<uint8_t>(0, 255), 255);
73    EXPECT_EQ(AddIgnoringOverflow<uint8_t>(1, 255), 0);
74  }
75  
76  }  // namespace