1 // Copyright 2009 Google Inc. All Rights Reserved. 2 // 3 // Redistribution and use in source and binary forms, with or without 4 // modification, are permitted provided that the following conditions are 5 // met: 6 // 7 // * Redistributions of source code must retain the above copyright 8 // notice, this list of conditions and the following disclaimer. 9 // * Redistributions in binary form must reproduce the above 10 // copyright notice, this list of conditions and the following disclaimer 11 // in the documentation and/or other materials provided with the 12 // distribution. 13 // * Neither the name of Google Inc. nor the names of its 14 // contributors may be used to endorse or promote products derived from 15 // this software without specific prior written permission. 16 // 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 29 // This sample shows how to use Google Test listener API to implement 30 // a primitive leak checker. 31 32 #include <stdio.h> 33 #include <stdlib.h> 34 35 #include "gtest/gtest.h" 36 using ::testing::EmptyTestEventListener; 37 using ::testing::InitGoogleTest; 38 using ::testing::Test; 39 using ::testing::TestEventListeners; 40 using ::testing::TestInfo; 41 using ::testing::UnitTest; 42 43 namespace { 44 // We will track memory used by this class. 45 class Water { 46 public: 47 // Normal Water declarations go here. 48 49 // operator new and operator delete help us control water allocation. 50 void* operator new(size_t allocation_size) { 51 allocated_++; 52 return malloc(allocation_size); 53 } 54 55 void operator delete(void* block, size_t /* allocation_size */) { 56 allocated_--; 57 free(block); 58 } 59 60 static int allocated() { return allocated_; } 61 62 private: 63 static int allocated_; 64 }; 65 66 int Water::allocated_ = 0; 67 68 // This event listener monitors how many Water objects are created and 69 // destroyed by each test, and reports a failure if a test leaks some Water 70 // objects. It does this by comparing the number of live Water objects at 71 // the beginning of a test and at the end of a test. 72 class LeakChecker : public EmptyTestEventListener { 73 private: 74 // Called before a test starts. 75 void OnTestStart(const TestInfo& /* test_info */) override { 76 initially_allocated_ = Water::allocated(); 77 } 78 79 // Called after a test ends. 80 void OnTestEnd(const TestInfo& /* test_info */) override { 81 int difference = Water::allocated() - initially_allocated_; 82 83 // You can generate a failure in any event handler except 84 // OnTestPartResult. Just use an appropriate Google Test assertion to do 85 // it. 86 EXPECT_LE(difference, 0) << "Leaked " << difference << " unit(s) of Water!"; 87 } 88 89 int initially_allocated_; 90 }; 91 92 TEST(ListenersTest, DoesNotLeak) { 93 Water* water = new Water; 94 delete water; 95 } 96 97 // This should fail when the --check_for_leaks command line flag is 98 // specified. 99 TEST(ListenersTest, LeaksWater) { 100 Water* water = new Water; 101 EXPECT_TRUE(water != nullptr); 102 } 103 } // namespace 104 105 int main(int argc, char** argv) { 106 InitGoogleTest(&argc, argv); 107 108 bool check_for_leaks = false; 109 if (argc > 1 && strcmp(argv[1], "--check_for_leaks") == 0) 110 check_for_leaks = true; 111 else 112 printf("%s\n", 113 "Run this program with --check_for_leaks to enable " 114 "custom leak checking in the tests."); 115 116 // If we are given the --check_for_leaks command line flag, installs the 117 // leak checker. 118 if (check_for_leaks) { 119 TestEventListeners& listeners = UnitTest::GetInstance()->listeners(); 120 121 // Adds the leak checker to the end of the test event listener list, 122 // after the default text output printer and the default XML report 123 // generator. 124 // 125 // The order is important - it ensures that failures generated in the 126 // leak checker's OnTestEnd() method are processed by the text and XML 127 // printers *before* their OnTestEnd() methods are called, such that 128 // they are attributed to the right test. Remember that a listener 129 // receives an OnXyzStart event *after* listeners preceding it in the 130 // list received that event, and receives an OnXyzEnd event *before* 131 // listeners preceding it. 132 // 133 // We don't need to worry about deleting the new listener later, as 134 // Google Test will do it. 135 listeners.Append(new LeakChecker); 136 } 137 return RUN_ALL_TESTS(); 138 } 139