我正在运行一个应用程序,由于分段错误而停止在一个点上。 我将尝试登记环境: - 应用程序有一个包含std :: string成员(数据)的类(Generator),并且该成员已正确初始化为“HelloWorld”。 - 此对象的指针传递给另一个类(Product)的成员函数(send1)。只要我尝试在函数内部打印数据的值,就会导致分段错误。如果我在调用send1函数之前尝试打印数据的值,它会正确打印。std :: string上的分段错误
下面是GDB输出:
(gdb) br Generator::test
Breakpoint 1 at 0x80499ef: file ../app/generator/src/generator.cpp, line 58.
(gdb) br Product::send1
Breakpoint 2 at 0x804a17e: file ../app/configurator/src/product.cpp, line 43.
(gdb) run
[Thread debugging using libthread_db enabled]
[New Thread -1208071520 (LWP 18389)]
[Switching to Thread -1208071520 (LWP 18389)]
Breakpoint 1, Generator::test (this=0x9917020) at ../app/generator/src/generator.cpp:58
58 cout << "data = " << this->data << endl;
(gdb) n
data = HelloWorld
59 Product* ptr = new Product;
(gdb) n
60 bool status = ptr->send1(this);
(gdb) s
Breakpoint 2, Product::send1 (this=0x99170c8, genptr=0x9917020) at ../app/configurator/src/product.cpp:43
43 cout << genptr->data << endl;
(gdb) p genptr->data
$1 = {static npos = 4294967295,
_M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>},
_M_p = 0x99170b4 "HelloWorld"}}
(gdb) n
Program received signal SIGSEGV, Segmentation fault.
0x076751e6 in std::operator<< <char, std::char_traits<char>, std::allocator<char> >() from /usr/lib/libstdc++.so.6
(gdb) bt
#0 0x076751e6 in std::operator<< <char, std::char_traits<char>, std::allocator<char> >() from /usr/lib/libstdc++.so.6
#1 0x0804a19a in Product::send1 (this=0x99170c8, genptr=0x9917020) at ../app/configurator/src/product.cpp:43
#2 0x08049a85 in Generator::test (this=0x9917020) at ../app/generator/src/generator.cpp:60
#3 0x08048f4c in Configure::init (this=0x9917008) at ../app/configurator/src/configurator.cpp:89
#4 0x08048c93 in main (argc=1, argv=0xbfed7364) at ../launch/main/src/appLaunch.cpp:20
(gdb)
这里是Valgrind的输出
valgrind --tool=memcheck --leak-check=yes ./application
==18328== Memcheck, a memory error detector.
==18328== Copyright (C) 2002-2005, and GNU GPL'd, by Julian Seward et al.
==18328== Using LibVEX rev 1575, a library for dynamic binary translation.
==18328== Copyright (C) 2004-2005, and GNU GPL'd, by OpenWorks LLP.
==18328== Using valgrind-3.1.1, a dynamic binary instrumentation framework.
==18328== Copyright (C) 2000-2005, and GNU GPL'd, by Julian Seward et al.
==18328== For more details, rerun with: -v
==18328==
data = HelloWorld
==18328== Invalid read of size 4
==18328== at 0x76751E6: std::basic_ostream<char, std::char_traits<char> >& std::operator<< <char, std::char_traits<char>, std::allocator<char> >(std::basic_ostream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) (in /usr/lib/libstdc++.so.6.0.3)
==18328== by 0x804A199: Product::send1(Generator*) (product.cpp:43)
==18328== by 0x8049A84: Generator::test() (generator.cpp:60)
==18328== by 0x8048F4B: Configure::init() (configurator.cpp:89)
==18328== by 0x8048C92: main (appLaunch.cpp:20)
==18328== Address 0x5C040234 is not stack'd, malloc'd or (recently) free'd
==18328==
==18328== Process terminating with default action of signal 11 (SIGSEGV)
==18328== Access not within mapped region at address 0x5C040234
==18328== at 0x76751E6: std::basic_ostream<char, std::char_traits<char> >& std::operator<< <char, std::char_traits<char>, std::allocator<char> >(std::basic_ostream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) (in /usr/lib/libstdc++.so.6.0.3)
==18328== by 0x804A199: Product::send1(Generator*) (product.cpp:43)
==18328== by 0x8049A84: Generator::test() (generator.cpp:60)
==18328== by 0x8048F4B: Configure::init() (configurator.cpp:89)
==18328== by 0x8048C92: main (appLaunch.cpp:20)
==18328==
==18328== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 17 from 1)
==18328== malloc/free: in use at exit: 159 bytes in 5 blocks.
==18328== malloc/free: 5 allocs, 0 frees, 159 bytes allocated.
==18328== For counts of detected errors, rerun with: -v
==18328== searching for pointers to 5 not-freed blocks.
==18328== checked 116,636 bytes.
这实际上是一个更大的应用程序的一部分,但我已经剥离了应用,并使其非常小,所以我可以很容易地调试这个问题,但即使现在我也不知道为什么会出现这个问题。使用gdb我试图检查内存布局,但在调用函数之前和之后内存地址和内容看起来完好无损。事实上,如果我试图使用gdb打印功能打印数据的值,它会出现是正确的。我已经尝试了很多事情,比如在堆上分配内存等,但似乎没有任何工作。请求您亲切指导我如何开始调试此问题。
很高兴知道您设法取消了应用程序,但您忘记了包含源代码。 – 2012-01-18 18:37:37
- 一些代码将非常有帮助 - 这些发电机和产品在同一个项目中吗?也许其中一个是在一个动态库? – Alek86 2012-01-18 19:00:21
是的发电机和产品都是同一个项目的一部分。我认为valgrind指向一个无效的读取,但我不知道如何解释和调试它。 – vchandra 2012-01-18 19:24:31