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 30 // This sample shows how to use Google Test listener API to implement 31 // a primitive leak checker. 32 33 #include <stdio.h> 34 #include <stdlib.h> 35 36 #include "gtest/gtest.h" 37 using ::testing::EmptyTestEventListener; 38 using ::testing::InitGoogleTest; 39 using ::testing::Test; 40 using ::testing::TestEventListeners; 41 using ::testing::TestInfo; 42 using ::testing::TestPartResult; 43 using ::testing::UnitTest; 44 45 namespace { 46 // We will track memory used by this class. 47 class Water { 48 public: 49 // Normal Water declarations go here. 50 51 // operator new and operator delete help us control water allocation. 52 void* operator new(size_t allocation_size) { 53 allocated_++; 54 return malloc(allocation_size); 55 } 56 57 void operator delete(void* block, size_t /* allocation_size */) { 58 allocated_--; 59 free(block); 60 } 61 62 static int allocated() { return allocated_; } 63 64 private: 65 static int allocated_; 66 }; 67 68 int Water::allocated_ = 0; 69 70 // This event listener monitors how many Water objects are created and 71 // destroyed by each test, and reports a failure if a test leaks some Water 72 // objects. It does this by comparing the number of live Water objects at 73 // the beginning of a test and at the end of a test. 74 class LeakChecker : public EmptyTestEventListener { 75 private: 76 // Called before a test starts. 77 virtual void OnTestStart(const TestInfo& /* test_info */) { 78 initially_allocated_ = Water::allocated(); 79 } 80 81 // Called after a test ends. 82 virtual void OnTestEnd(const TestInfo& /* test_info */) { 83 int difference = Water::allocated() - initially_allocated_; 84 85 // You can generate a failure in any event handler except 86 // OnTestPartResult. Just use an appropriate Google Test assertion to do 87 // it. 88 EXPECT_LE(difference, 0) << "Leaked " << difference << " unit(s) of Water!"; 89 } 90 91 int initially_allocated_; 92 }; 93 94 TEST(ListenersTest, DoesNotLeak) { 95 Water* water = new Water; 96 delete water; 97 } 98 99 // This should fail when the --check_for_leaks command line flag is 100 // specified. 101 TEST(ListenersTest, LeaksWater) { 102 Water* water = new Water; 103 EXPECT_TRUE(water != NULL); 104 } 105 } // namespace 106 107 int main(int argc, char **argv) { 108 InitGoogleTest(&argc, argv); 109 110 bool check_for_leaks = false; 111 if (argc > 1 && strcmp(argv[1], "--check_for_leaks") == 0 ) 112 check_for_leaks = true; 113 else 114 printf("%s\n", "Run this program with --check_for_leaks to enable " 115 "custom leak checking in the tests."); 116 117 // If we are given the --check_for_leaks command line flag, installs the 118 // leak checker. 119 if (check_for_leaks) { 120 TestEventListeners& listeners = UnitTest::GetInstance()->listeners(); 121 122 // Adds the leak checker to the end of the test event listener list, 123 // after the default text output printer and the default XML report 124 // generator. 125 // 126 // The order is important - it ensures that failures generated in the 127 // leak checker's OnTestEnd() method are processed by the text and XML 128 // printers *before* their OnTestEnd() methods are called, such that 129 // they are attributed to the right test. Remember that a listener 130 // receives an OnXyzStart event *after* listeners preceding it in the 131 // list received that event, and receives an OnXyzEnd event *before* 132 // listeners preceding it. 133 // 134 // We don't need to worry about deleting the new listener later, as 135 // Google Test will do it. 136 listeners.Append(new LeakChecker); 137 } 138 return RUN_ALL_TESTS(); 139 } 140