1.Exception类实现
(1)
backtrace,栈回溯,保存各个栈帧的地址
(2)backtrace_symbols,根据地址,转成相应的函数符号
(3)abi::__cxa_demangle
2.代码
Exception.h
// Use of this source code is governed by a BSD-style license
// that can be found in the License file.
//
// Author: Shuo Chen (chenshuo at chenshuo dot com)
#ifndef MUDUO_BASE_EXCEPTION_H
#define MUDUO_BASE_EXCEPTION_H
#include
#include
namespace muduo
{
class Exception : public std::exception
{
public:
explicit Exception(const char* what);
explicit Exception(const string& what);
virtual ~Exception() throw();
virtual const char* what() const throw();
const char* stackTrace() const throw();
private:
void fillStackTrace();
string demangle(const char* symbol);
string message_;
string stack_;
};
}
#endif // MUDUO_BASE_EXCEPTION_H
Exception.cc
// Use of this source code is governed by a BSD-style license
// that can be found in the License file.
//
// Author: Shuo Chen (chenshuo at chenshuo dot com)
#include
#include
#include
#include
#include
using namespace muduo;
Exception::Exception(const char* msg)
: message_(msg)
{
fillStackTrace();
}
Exception::Exception(const string& msg)
: message_(msg)
{
fillStackTrace();
}
Exception::~Exception() throw ()
{
}
const char* Exception::what() const throw()
{
return message_.c_str();
}
const char* Exception::stackTrace() const throw()
{
return stack_.c_str();
}
void Exception::fillStackTrace()
{
const int len = 200;
void* buffer[len];
int nptrs = ::backtrace(buffer, len);
char** strings = ::backtrace_symbols(buffer, nptrs);
if (strings)
{
for (int i = 0; i < nptrs; ++i)
{
// TODO demangle funcion name with abi::__cxa_demangle
//stack_.append(strings[i]);
stack_.append(demangle(strings[i]));
stack_.push_back('\n');
}
free(strings);
}
}
string Exception::demangle(const char* symbol)
{
size_t size;
int status;
char temp[128];
char* demangled;
//first, try to demangle a c++ name
if (1 == sscanf(symbol, "%*[^(]%*[^_]%127[^)+]", temp)) {
if (NULL != (demangled = abi::__cxa_demangle(temp, NULL, &size, &status))) {
string result(demangled);
free(demangled);
return result;
}
}
//if that didn't work, try to get a regular c symbol
if (1 == sscanf(symbol, "%127s", temp)) {
return temp;
}
//if all else fails, just return the symbol
return symbol;
}
Exception_test.cpp
#include
#include
class Bar
{
public:
void test()
{
throw muduo::Exception("oops");
}
};
void foo()
{
Bar b;
b.test();
}
int main()
{
try
{
foo();
}
catch (const muduo::Exception& ex)
{
printf("reason: %s\n", ex.what());
printf("stack trace: %s\n", ex.stackTrace());
}
}
执行结果