CppUnit，很简单的测试代码崩溃了，为什么？

Question

我正在学习 CppUnit，我的代码在调用 TestRunner::run() 时被转储。这是下面代码中的第 34 行。我看不出有什么不对。它与 CppUnit 食谱中的示例代码几乎相同。

#include <iostream>  
#include <cppunit/TestCaller.h>  
#include <cppunit/TestSuite.h>  
#include <cppunit/ui/text/TestRunner.h>  
using namespace std;  

//class MyFixture: public CppUnit::TestFixture {  
class MyFixture{  
public:  
   MyFixture() {cout<<"MyFixture:: ctor()"<<endl;}  
   ~MyFixture() {cout<<"MyFixture:: dtor()"<<endl;}  
   void setUp() {cout<<"MyFixture::Setup()"<<endl;}  
   void tearDown() {cout<<"MyFixture::tearDown()"<<endl;}  
   void testFunc1() {cout<<"MyFixture::testFunc1()"<<endl; m=1; CPPUNIT_ASSERT(m==1);}  
   void testFunc2() {cout<<"MyFixture::testFunc2()"<<endl; m=2;}  
   int m;  
   static CppUnit::TestSuite * CreateSuite();  
};  

CppUnit::TestSuite * MyFixture::CreateSuite()  
{  
   CppUnit::TestSuite * suite = new CppUnit::TestSuite("My TestSuite for MyFixture");  
   suite->addTest(new CppUnit::TestCaller<MyFixture>("MyFixture::testFunc1", &MyFixture::testFunc1));  
   suite->addTest(new CppUnit::TestCaller<MyFixture>("MyFixture::testFunc2", &MyFixture::testFunc2));  
}  

int main()  
{  
   cout<<"point 1000"<<endl;  
   CppUnit::TextUi::TestRunner runner;  
   runner.addTest(MyFixture::CreateSuite());  
   cout<<"point 7000"<<endl;  
/*Line34*/   runner.run();  


   cout<<"point 8000"<<endl;  
}  

输出：

  cppunit$ ./test_runner   
  point 1000  
  MyFixture:: ctor()  
  MyFixture:: ctor()  
  point 7000  
  Segmentation fault (core dumped)  

堆栈跟踪：

(gdb)bt  
-0  0x00733cc9 in CppUnit::TestRunner::WrappingSuite::run(CppUnit::TestResult*) ()  
   from /usr/lib/libcppunit-1.12.so.1  
-1  0x0073170a in CppUnit::TestResult::runTest(CppUnit::Test*) () from /usr/lib/libcppunit-1.12.so.1  
-2  0x00733af0 in CppUnit::TestRunner::run(CppUnit::TestResult&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) () from /usr/lib/libcppunit-1.12.so.1  
-3  0x00736d2b in CppUnit::TextTestRunner::run(CppUnit::TestResult&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) () from /usr/lib/libcppunit-1.12.so.1  
-4  0x00736da2 in CppUnit::TextTestRunner::run(std::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, bool, bool) () from /usr/lib/libcppunit-1.12.so.1  
-5  0x080494dd in main () at test_runner.cpp:34  

编译行：g++ -g -o -Wall test_runner test_runner.cpp -lcppunit
它编译成功，没有任何警告。
如果我打开“-Wall”，它会报错：

......
(.data+0x4): multiple definition of `__dso_handle'  
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/crtbegin.o:(.data+0x0): first defined here  
test_runner: In function `_init':  
(.init+0x0): multiple definition of `_init'  
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/../../../crti.o:(.init+0x0): first defined here  
/tmp/ccgzqvu9.o: In function `MyFixture::CreateSuite()':  
/home/fzhao/temp/cppunit/test_runner.cpp:22: multiple definition of `MyFixture::CreateSuite()'  
test_runner:/home/fzhao/temp/cppunit/test_runner.cpp:22: first defined here  
/tmp/ccgzqvu9.o: In function `main':  
/home/fzhao/temp/cppunit/test_runner.cpp:29: multiple definition of `main'  
test_runner:/home/fzhao/temp/cppunit/test_runner.cpp:29: first defined here  
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/crtend.o:(.dtors+0x0): multiple definition of `__DTOR_END__'  
test_runner:(.dtors+0x4): first defined here  
/usr/bin/ld: warning: Cannot create .eh_frame_hdr section, --eh-frame-hdr ignored.  
/usr/bin/ld: error in test_runner(.eh_frame); no .eh_frame_hdr table will be created.  
collect2: ld returned 1 exit status  
make: *** [test_runner] Error 1  

Answer 1

假设函数的签名是：

CppUnit::TestSuite * MyFixture::CreateSuite()

你不应该返回什么吗（suite 是我的第一个猜测）？

不返回任何东西，行：

runner.addTest(MyFixture::CreateSuite());

将为您的runner 添加一个非常狡猾的指针。

---

您在插入 -Wall 时可能遇到这些错误的原因是：

g++ -g -o -Wall test_runner test_runner.cpp -lcppunit
       \______/ \___________________________________/

将尝试通过将test_runner、test_runner.cpp 和cppunit 库链接在一起，将您的可执行文件输出到文件-Wall。也许您打算输入：

g++ -g -Wall -o test_runner test_runner.cpp -lcppunit
             \____________/ \_______________________/

（我在这里假设您给出的编译行是发生错误的行，因为它实际上有 -Wall 在其中）。