在Google模拟中双免费

Double free in Google Mock

本文关键字：免费 模拟 Google      更新时间：2023-10-16

我是Google测试和模拟框架中的新手。

我只是尝试运行"乌龟"例子，这是成功的。

但是，显示错误消息：双免费或损坏（！prev）。

oigturtle.h 

#include <gmock/gmock.h>
class MockTurtle : class Turtle {
    MOCK_METHOD0(PenUp, void());
    MOCK_METHOD0(PenDown, void());
    MOCK_METHOD1(Forward, void(int distance));
    MOCK_METHOD1(Turn, void(int degrees));
    MOCK_METHOD2(GoTo, void(int x, int y));
    MOCK_CONST_METHOD0(GetX, int());
    MOCK_CONST_METHOD0(GetY, int());
};

Turtle.h 

class Turtle {
    virtual ~Turtle() {}
    virtual void PenUp() = 0;
    virtual void PenDown() = 0;
    virtual void Forward(int distance) = 0;
    virtual void Turn(int degrees) = 0;
    virtual void GoTo(int x, int y) = 0;
    virtual int GetX() const = 0;
    virtual int GetY() const = 0;
};

Painter.h 

class Painter    
{
       Turtle* turtle;
public:
       Painter( Turtle* turtle )
               :       turtle(turtle){}
       bool DrawCircle(int, int, int){
               turtle->PenDown();
               return true;
       }
};    

main_test.cpp 

#include <gtest/gtest.h>
#include <gmock/gmock.h>
#include "Painter.h"
#include "MockTurtle.h"
using ::testing::AtLeast;
TEST(PainterTest, CanDrawSomething) {
 MockTurtle turtle;
 EXPECT_CALL(turtle, PenDown())
     .Times(AtLeast(1));
 Painter painter(&turtle);
 EXPECT_TRUE(painter.DrawCircle(0, 0, 10));
}
int main(int argc, char** argv) {
 // The following line must be executed to initialize Google Mock
 // (and Google Test) before running the tests.
 ::testing::InitGoogleMock(&argc, argv);
 return RUN_ALL_TESTS();
}    

结果

[==========] Running 1 test from 1 test case.    
[----------] Global test environment set-up.
[----------] 1 test from PainterTest
[ RUN      ] PainterTest.CanDrawSomething
[       OK ] PainterTest.CanDrawSomething (0 ms)
[----------] 1 test from PainterTest (0 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (1 ms total)
[  PASSED  ] 1 test.
*** Error in `/home/user/workspace/google_mock_2/Debug/google_mock_2': double free or corruption (!prev): 0x098a8080 ***

我尝试使用Google，看到了几个相同的问题。人们说，这不应将模拟用作全局变量。

但是我的示例没有使用全局变量。

请帮助我解释为什么双重自由发生。预先感谢！

上次，我在共享库中构建了Google Test和Google模拟。

发生了错误（双免费）。

我试图构建为静态库。此错误不再出现。我不知道为什么，但是我会调查以了解更多细节。

我也有同样的问题。就我而言，问题是要链接Google测试和Google Mock。我仅通过链接gmock，没有gtest来解决问题。

我认为这是因为据我所知，Gmock已经链接了静态的GTEST：当您将Gmock编译成动态库时，GTEST也会在同一文件夹中生成gtest（作为静态库），在该文件夹中构建了Gomock。我想Gmock取决于和使用此库。

我想，以某种方式将GTEST链接两次（无论是静态还是动态），会产生一个免费的（），要执行两次。

对于您的信息，这是gtest/gmock中的一个错误，用于cmake共享库的构建。该拉的请求已经解决了。有关更多详细信息，请阅读第930期中的讨论。

您的错误是您没有显示我们的地方。我设法添加了足够的标题和定义，以使您的示例进行编译：

#include <gtest/gtest.h>
#include <gmock/gmock.h>
class Turtle {
public:
    virtual ~Turtle() = default;
    virtual void PenDown() = 0;
};
class MockTurtle : public Turtle {
public:
    MOCK_METHOD0(PenDown, void());
};

class Painter
{
    Turtle *turtle;
public:
    Painter(Turtle *turtle)
        : turtle(turtle)
    {}
    bool DrawCircle(int, int, int)
    {
        turtle->PenDown();
        return true;
    }
};
TEST(PainterTest, CanDrawSomething)
{
    MockTurtle turtle;
    EXPECT_CALL(turtle, PenDown()).Times(testing::AtLeast(1));
    Painter painter(&turtle);
    EXPECT_TRUE(painter.DrawCircle(0, 0, 10));
}

使用此makefile：

VPATH += $(GTEST_DIR)/src
VPATH += $(GMOCK_DIR)/src
gtest%.o: CPPFLAGS += -I$(GTEST_DIR)
gmock%.o: CPPFLAGS += -I$(GMOCK_DIR)
40762798: CXXFLAGS += -isystem $(GTEST_DIR)/include -isystem $(GMOCK_DIR)
40762798: CXXFLAGS += -pthread -Wno-effc++
40762798: LDLIBS += -lpthread
40762798: CC=g++
40762798: 40762798.o gtest_main.o gtest-all.o gmock-all.o

然后我没有任何错误，瓦尔格林德给了一个清晰的健康账单：

valgrind  ./40762798 
==24351== Memcheck, a memory error detector
==24351== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==24351== Using Valgrind-3.12.0.SVN and LibVEX; rerun with -h for copyright info
==24351== Command: ./40762798
==24351== 
Running main() from gtest_main.cc
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from PainterTest
[ RUN      ] PainterTest.CanDrawSomething
[       OK ] PainterTest.CanDrawSomething (84 ms)
[----------] 1 test from PainterTest (92 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (125 ms total)
[  PASSED  ] 1 test.
==24351== 
==24351== HEAP SUMMARY:
==24351==     in use at exit: 0 bytes in 0 blocks
==24351==   total heap usage: 183 allocs, 183 frees, 117,387 bytes allocated
==24351== 
==24351== All heap blocks were freed -- no leaks are possible
==24351== 
==24351== For counts of detected and suppressed errors, rerun with: -v
==24351== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
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