首先这篇文章总结得不错
https://blog.csdn.net/stpeace/article/details/73302833
然后依然会碰到问题,这时候就要看具体的函数签名了
Name Mangling in C++
参考
http://blog.51cto.com/hipercomer/855223
name demangling
C++的name mangling技术一般使得函数变得面目全非,而很多情况下我们在查看这些符号的时候并不需要看到这些函数name mangling之后的效果,而是想看看是否定义了某个函数,或者是否引用了某个函数,这对于我们调试程序是非常有帮助的。
所以需要一种方法从name mangling之后的符号变换为name mangling之前的符号,这个过程称之为name demangling.事实上有很多工具提供这些功能,最常用的就是c++file命令,c++filt命令接受一个name mangling之后的符号作为输入并输出demangling之后的符号。例如:
[lichao@sg01 name_mangling]$ c++filt _Z9test_funcRiPKcdSsf test_func(int&, char const*, double, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, float)
一般更常用的方法为:
[lichao@sg01 name_mangling]$ nm func.o | c++filt 0000000000000060 t global constructors keyed to _Z9test_funcRiPKcdSsf U _Unwind_Resume 0000000000000022 t __static_initialization_and_destruction_0(int, int) 0000000000000000 T test_func(int&, char const*, double, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, float) U std::allocator<char>::allocator() U std::allocator<char>::~allocator() U std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&) U std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) U std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string() U std::ios_base::Init::Init() U std::ios_base::Init::~Init() 0000000000000000 b std::__ioinit U __cxa_atexit U __dso_handle U __gxx_personality_v0 0000000000000076 t __tcf_0 000000000000008e T main 另外使用nm命令也可以demangle符号,使用选项-C即可,例如: [lichao@sg01 name_mangling]$ nm -C func.o 0000000000000060 t global constructors keyed to _Z9test_funcRiPKcdSsf U _Unwind_Resume 0000000000000022 t __static_initialization_and_destruction_0(int, int) 0000000000000000 T test_func(int&, char const*, double, std::string, float) U std::allocator<char>::allocator() U std::allocator<char>::~allocator() U std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&) U std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::string const&) U std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string() U std::ios_base::Init::Init() U std::ios_base::Init::~Init() 0000000000000000 b std::__ioinit U __cxa_atexit U __dso_handle U __gxx_personality_v0 0000000000000076 t __tcf_0 000000000000008e T main
又到了Last but not least important的时候了,还有一个特别重要的接口函数就是__cxa_demangle(),此函数的原型为:
namespace abi { extern "C" char* __cxa_demangle (const char* mangled_name, char* buf, size_t* n, int* status); }
用于将mangled_name所指向的mangled进行demangle并将结果存放在buf中,n为buf的大小。status存放函数执行的结果,返回值为0表示执行成功。
下面是使用这个接口函数进行demangle的例子:
/* * Author: Chaos Lee * Description: Employ __cxa_demangle to demangle a mangling function name. * Date:2012/05/06 * */ #include<iostream> #include<cxxabi.h> using namespace std; using namespace abi; int main(int argc,char *argv[]) { const char * mangled_string = "_Z9test_funcRiPKcdSsf"; char buffer[100]; int status; size_t n=100; __cxa_demangle(mangled_string,buffer,&n,&status); cout<<buffer<<endl; cout<<status<<endl; return 0; }
测试结果:
[lichao@sg01 name_mangling]$ g++ cxa_demangle.cpp -o cxa_demangle
[lichao@sg01 name_mangling]$ ./cxa_demangle
test_func(int&, char const*, double, std::string, float)
0