为什么我会丢失 SWIG、C++、python 的异常

【问题标题】：Why am I losing exceptions with SWIG, C++, python为什么我会丢失 SWIG、C++、python 的异常
【发布时间】：2014-04-14 06:09:51
【问题描述】：

我在这里疯了。我希望在 C++ 中捕获异常，以便我可以将它们映射到 python 中的自定义异常类。我现在得到的只是 python 异常。我无法在生成的代码中捕获我的异常？？？

程序：

#!/usr/bin/python

import os
import sys
import hpsphal_python

prog = os.path.basename(__file__) + ": "

try:
    hal = hpsphal_python.System_getSystem()
    scs = hal.getStorageClusters()
    if len(scs) == 0:
        print >>sys.stderr, prog + "No storage clusters found."
        os._exit(-1)

    for sc in scs:
        print "sc: ", sc.getUUID()
        conts = sc.getControllers()
        for c in conts:
            try:
                c.setClock()
            except hpsphal_python.Exception as e:
                print "he: ", e.what()
            except RuntimeError as e:
                print "rt: ", e, e[0]
            except Exception as e:
                print "e: ", e, e[0]

    os._exit(0)
except Exception, e:
    print "E: ", e
    os._exit(-1)

输出：

sc:  222367ad-0005-1000-95ab-415a34303736
e:  setControllerClock setControllerClock
e:  setControllerClock setControllerClock
sc:  MXQ04205MV_Con_0_Cluster
e:  setControllerClock setControllerClock

实际上捕获异常的 C++ 中的相同代码：

#include "time.h"

#include <iostream>
#include <map>
#include <set>
#include <string>
#include <exception>

#include <boost/foreach.hpp>
#include <boost/regex.hpp>
#include <boost/thread/thread.hpp>

#include "Exception.hpp"
#include "StorageCluster.hpp"
#include "Controller.hpp"
#include "System.hpp"

using namespace std;

int main (int argc, char *argv[])
{
    danAPI::SystemPtr danSystem;
    try {
        danSystem = danAPI::System::getSystem();
    }
    catch(danAPI::Exception& e) {
        cerr << "Unable to initialize danAPI" << e.what() << endl;
        return -1;
    }

    try {
        danAPI::StorageClusterPtrList danStorageClusters = danSystem->getStorageClusters();
        BOOST_FOREACH(danAPI::StorageClusterPtr sc, danStorageClusters)
        {
            danAPI::ControllerPtrList danStorageControllers = sc->getControllers();
            BOOST_FOREACH(danAPI::ControllerPtr c, danStorageControllers)
            {
                try {
                    c->setClock();
                }
                catch(danAPI::Exception& e) {
                    cerr << "HAL Exception: " << e.what() << endl;
                }
                catch(exception& e) {
                    cerr << "Standard Exception: " << e.what() << endl;
                }
            }
        }
    }
    catch(exception& e) {
        cerr << "Unable to get storage clusters: " << e.what() << endl;
    }

    return 0;
}

输出：

HAL Exception: setControllerClock: SetClock exception: function failed (1)
/jenkins/workspace/ts1.4-hpsphal/storage-lib/src/Raptor.cpp: 1100
/jenkins/workspace/ts1.4-hpsphal/storage-lib/src/Raptor.cpp: 791
(1)
/jenkins/workspace/ts1.4-hpsphal/storage-lib/src/StorageCluster_Rcim.cpp: 2158

HAL Exception: setControllerClock: SetClock exception: function failed (1)
/jenkins/workspace/ts1.4-hpsphal/storage-lib/src/Raptor.cpp: 1100
/jenkins/workspace/ts1.4-hpsphal/storage-lib/src/Raptor.cpp: 791
(1)
/jenkins/workspace/ts1.4-hpsphal/storage-lib/src/StorageCluster_Rcim.cpp: 2158

玩家：

custom Exception class
SWIG 2.0.12
boost 1.41 throw_exception

我生成的代码中的一个 sn-p：

  {
    try {
      (arg1)->setClock();
    } catch(danAPI::Exception& e) {
      std::cerr << "++++++" << std::endl;
    } catch(std::exception& e) {
      std::cerr << "++++++" << std::endl;
    } catch(boost::exception& e) {
      std::cerr << "++++++" << std::endl;
    } catch(...) {
      std::cerr << "++++++" << std::endl;
    }
  }
  resultobj = SWIG_Py_Void();
  return resultobj;
fail:
  return NULL;

这是我的 .i 文件（hdrs 宏用我的头文件填充）

%include "stdint.i"
%include "stl.i"
%include "std_string.i"
%include "std_vector.i"
%include "std_string.i"
%include "std_pair.i"
%include "std_set.i"
%include "typemaps.i"

%apply unsigned long long &OUTPUT { unsigned long long &firstCharInBuffer };
%apply unsigned long long &OUTPUT { unsigned long long &nextChar };
%exceptionclass danAPI::Exception;

%exception {
    try {
        $action
    }
    catch(danAPI::Exception &e)
    {
        SWIG_Python_Raise(SWIG_NewPointerObj(
            (new danAPI::Exception(static_cast<const danAPI::Exception&>(e))),
            SWIGTYPE_p_danAPI__Exception,SWIG_POINTER_OWN),
            "Exception", SWIGTYPE_p_danAPI__Exception);
       SWIG_fail;
    }
}

// need to define the templates for shared_ptr<T> before we define the
// various T's below; put in a common place so the various SWIG interfaces
// stay in sync
%include "hpsphal_ptrs.i"

%{
    ${hash_public_headers}
    using namespace danAPI;
%}

${percent_public_headers}

// need to define the vector types after we've defined the types
// themselves; moved to a common place to keep the various SWIG interfaces
// in sync
%include "hpsphal_vectors.i"

我在 gdb 中运行了我的代码，“catch throw”。我看到了一些我在库内部捕获的异常。我的库应该抛出 3 个异常，然后被我的 SWIG 代码捕获。

这是内部捕获的：

#0  0x000000337c8bccb0 in __cxa_throw () from /usr/lib64/libstdc++.so.6
#1  0x00007ffff122a1ac in boost::throw_exception<danAPI::Exception> (e=...) at /usr/include/boost/throw_exception.hpp:64
#2  0x00007fffef398841 in danAPI::StorageClusterFactory::getStorageControllerType (this=0x7fffffffd6d0, path="/dev/sg4")
    at /home/chchr/src/hpsphal/storage-lib/src/StorageClusterFactory.cpp:247
#3  0x00007fffef398aa8 in danAPI::StorageClusterFactory::createStorageCluster (this=0x7fffffffd6d0, path="/dev/sg4",
    storclustpList=std::vector of length 1, capacity 1 = {...}, cluster=std::tr1::shared_ptr (empty) 0x0, err=...)
    at /home/chchr/src/hpsphal/storage-lib/src/StorageClusterFactory.cpp:308
#4  0x00007fffef3a262c in boost::_mfi::cmf4<void, danAPI::StorageClusterFactory, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, danAPI::ConstStorageClusterPtrList const&, danAPI::ConstStorageClusterPtr&, boost::exception_ptr&>::call<danAPI::StorageClusterFactory const* const, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::tr1::shared_ptr<danAPI::StorageCluster const>, std::allocator<std::tr1::shared_ptr<danAPI::StorageCluster const> > > const, std::tr1::shared_ptr<danAPI::StorageCluster const>, boost::exception_ptr> (this=0x896740, u=@0x896750, b1=
    "/dev/sg4", b2=std::vector of length 1, capacity 1 = {...}, b3=std::tr1::shared_ptr (empty) 0x0, b4=...)
    at /usr/include/boost/bind/mem_fn_template.hpp:547
#5  0x00007fffef3a2466 in boost::_mfi::cmf4<void, danAPI::StorageClusterFactory, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, danAPI::ConstStorageClusterPtrList const&, danAPI::ConstStorageClusterPtr&, boost::exception_ptr&>::operator()<danAPI::StorageClusterFactory const*> (
    this=0x896740, u=@0x896750, a1="/dev/sg4", a2=std::vector of length 1, capacity 1 = {...}, a3=std::tr1::shared_ptr (empty) 0x0, a4=...)
    at /usr/include/boost/bind/mem_fn_template.hpp:556
#6  0x00007fffef3a21d4 in boost::_bi::list5<boost::_bi::value<danAPI::StorageClusterFactory const*>, boost::_bi::value<char*>, boost::reference_wrapper<std::vector<std::tr1::shared_ptr<danAPI::StorageCluster const>, std::allocator<std::tr1::shared_ptr<danAPI::StorageCluster const> > > >, boost::reference_wrapper<std::tr1::shared_ptr<danAPI::StorageCluster const> >, boost::reference_wrapper<boost::exception_ptr> >::operator()<boost::_mfi::cmf4<void, danAPI::StorageClusterFactory, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, danAPI::ConstStorageClusterPtrList const&, danAPI::ConstStorageClusterPtr&, boost::exception_ptr&>, boost::_bi::list0> (this=0x896750, f=..., a=...) at /usr/include/boost/bind/bind.hpp:518
#7  0x00007fffef3a1e0d in boost::_bi::bind_t<void, boost::_mfi::cmf4<void, danAPI::StorageClusterFactory, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, danAPI::ConstStorageClusterPtrList const&, danAPI::ConstStorageClusterPtr&, boost::exception_ptr&>, boost::_bi::list5<boost::_bi::value<danAPI::StorageClusterFactory const*>, boost::_bi::value<char*>, boost::reference_wrapper<std::vector<std::tr1::shared_ptr<danAPI::StorageCluster const>, std::allocator<std::tr1::shared_ptr<danAPI::StorageCluster const> > > >, boost::reference_wrapper<std::tr1::shared_ptr<danAPI::StorageCluster const> >, boost::reference_wrapper<boost::exception_ptr> > >::operator() (this=0x896740) at /usr/include/boost/bind/bind_template.hpp:20
#8  0x00007fffef3a19cc in boost::detail::thread_data<boost::_bi::bind_t<void, boost::_mfi::cmf4<void, danAPI::StorageClusterFactory, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, danAPI::ConstStorageClusterPtrList const&, danAPI::ConstStorageClusterPtr&, boost::exception_ptr&>, boost::_bi::list5<boost::_bi::value<danAPI::StorageClusterFactory const*>, boost::_bi::value<char*>, boost::reference_wrapper<std::vector<std::tr1::shared_ptr<danAPI::StorageCluster const>, std::allocator<std::tr1::shared_ptr<danAPI::StorageCluster const> > > >, boost::reference_wrapper<std::tr1::shared_ptr<danAPI::StorageCluster const> >, boost::reference_wrapper<boost::exception_ptr> > > >::run (this=0x896610) at /usr/include/boost/thread/detail/thread.hpp:56
#9  0x00007fffed8c2d97 in thread_proxy () from /usr/lib64/libboost_thread-mt.so.5
#10 0x000000337a007851 in start_thread () from /lib64/libpthread.so.0
#11 0x00000033794e811d in clone () from /lib64/libc.so.6

那么我之前应该从 setControllerClock() 得到 2 个：

#0  0x000000337c8bccb0 in __cxa_throw () from /usr/lib64/libstdc++.so.6
#1  0x00007ffff143fc4c in swig::SwigPyIteratorClosed_T<__gnu_cxx::__normal_iterator<std::tr1::shared_ptr<danAPI::Controller>*, std::vector<std::tr1::shared_ptr<danAPI::Controller>, std::allocator<std::tr1::shared_ptr<danAPI::Controller> > > >, std::tr1::shared_ptr<danAPI::Controller>, swig::from_oper<std::tr1::shared_ptr<danAPI::Controller> > >::value (this=0x87bf50) at /home/chchr/src/hpsphal/build/python/hpsphalPYTHON_wrap.cxx:4894
#2  0x00007ffff101ddb7 in swig::SwigPyIterator::next (this=0x87bf50) at /home/chchr/src/hpsphal/build/python/hpsphalPYTHON_wrap.cxx:3472
#3  0x00007ffff07a083c in _wrap_SwigPyIterator_next (args=0x7ffff7f69850) at /home/chchr/src/hpsphal/build/python/hpsphalPYTHON_wrap.cxx:14301
#4  0x000000337b8deb24 in PyEval_EvalFrameEx () from /usr/lib64/libpython2.6.so.1.0
#5  0x000000337b8e0797 in PyEval_EvalCodeEx () from /usr/lib64/libpython2.6.so.1.0
#6  0x000000337b86edb0 in ?? () from /usr/lib64/libpython2.6.so.1.0
#7  0x000000337b844303 in PyObject_Call () from /usr/lib64/libpython2.6.so.1.0
#8  0x000000337b85970f in ?? () from /usr/lib64/libpython2.6.so.1.0
#9  0x000000337b844303 in PyObject_Call () from /usr/lib64/libpython2.6.so.1.0
#10 0x000000337b89d5eb in ?? () from /usr/lib64/libpython2.6.so.1.0
#11 0x000000337b8da458 in PyEval_EvalFrameEx () from /usr/lib64/libpython2.6.so.1.0
#12 0x000000337b8e0797 in PyEval_EvalCodeEx () from /usr/lib64/libpython2.6.so.1.0
#13 0x000000337b8e0872 in PyEval_EvalCode () from /usr/lib64/libpython2.6.so.1.0
#14 0x000000337b8fbbbc in ?? () from /usr/lib64/libpython2.6.so.1.0
#15 0x000000337b8fbc90 in PyRun_FileExFlags () from /usr/lib64/libpython2.6.so.1.0
#16 0x000000337b8fd17c in PyRun_SimpleFileExFlags () from /usr/lib64/libpython2.6.so.1.0
#17 0x000000337b909c32 in Py_Main () from /usr/lib64/libpython2.6.so.1.0
#18 0x000000337941ecdd in __libc_start_main () from /lib64/libc.so.6
#19 0x0000000000400649 in _start ()

c++ 程序中的catch throw：

Catchpoint 1 (exception thrown), 0x000000337c8bccb0 in __cxa_throw () from /usr/lib64/libstdc++.so.6
(gdb) bt
#0  0x000000337c8bccb0 in __cxa_throw () from /usr/lib64/libstdc++.so.6
#1  0x00007ffff6e9610c in boost::throw_exception<danAPI::Exception> (e=...) at /usr/include/boost/throw_exception.hpp:64
#2  0x00007ffff72a065f in danAPI::Controller_Rcim::setClock (this=0x641430) at /home/chchr/src/hpsphal/storage-lib/src/Controller_Rcim.cpp:2128
#3  0x00000000004072ac in main (argc=1, argv=0x7fffffffe728) at /home/chchr/src/hpsphal/python/foo.cpp:39

【问题讨论】：

    标签： python c++ exception boost swig


    【解决方案1】：

    在您的 .i 文件中，您的 %exception 块在函数周围放置一个 try，然后在每个 catch 子句中，它打印错误然后继续执行，就好像没有异常一样。这肯定不是您想要的，因为结果是您不会将任何异常传播到 Python（您怎么可能？您已经告诉 SWIG 生成代码以忽略它们）。使用 exception.i，如 section 11.1.7 of the SWIG manual 中所述。例如，

    %include exception.i       

%exception {
    try {
        $action
    } catch(const danAPI::Exception& e) {
        SWIG_exception(SWIG_ValueError, "Dan API exception");
    } catch(const std::exception& e) {
        SWIG_exception(SWIG_UnknownError, "Standard exception");
    } catch(const boost::exception& e) {
        SWIG_exception(SWIG_UnknownError, "Boost exception");
    } catch(...) {
        SWIG_exception(SWIG_RuntimeError, "Unknown exception");
    }
}

    我从未查看过生成的代码，但我的猜测是 SWIG_exception 会导致设置一些标志，SWIG 在执行 $action 后检查该标志，如果设置，则 SWIG 使用 Python API 引发 Python 异常。

    更新：

    如果您甚至没有看到错误消息并且您没有到达 catch 子句，那么您的 C++ 库就没有抛出异常。问题不在于包装代码 (setControllerClock)，而是您自己的 setClock 的 C++ 库代码，或者您可能没有在会引发异常的上下文中调用它。您的问题与生成的代码、SWIG 或 Python 无关。这是你的图书馆。

    为了证明这一点：在你的 $action 行后面加上一个throw std::runtime_error("test")。您将在第二个 catch 子句中结束，e.what() 将是 "test"：

    %exception {
    try {
        $action
        throw std::runtime_error("test");
    } catch(const danAPI::Exception& e) {
        SWIG_exception(SWIG_ValueError, "Dan API exception");
    } catch(const std::exception& e) {
        SWIG_exception(SWIG_UnknownError, "Standard exception");

    【讨论】：

    • 我剥离了代码进行调试。我在生成的代码中根本没有到达 catch() 块。我从来没有在标准错误中看到“++++”，我期待看到我的库和我的包装代码之间抛出的异常。您是正确的，当前编写的包装器代码不会引发异常。
    • 问题不在于包装代码，而在于您的 C++ 代码。如果您从未到达您的 catch 块，那么您的 C++ 函数不会引发异常。在您的 $action 行之后放置一个throw std::runtime_error("test")，它将起作用。问题是 setControllerClock 调用的 C++ 函数没有抛出。这似乎与生成的代码无关。
    • 现在我们正在讨论让我难过的问题。我将打印代码放在从未执行的 $action 之后。我在上面附加了 C++ 代码，它与 python 代码做同样的事情（成功地）。此外，python 代码的输出告诉我，我从应该从中捕获 C++ 异常的方法中捕获了 python 异常。
    • @ChipChristian 我已经更新了我的帖子，也许现在会更清楚了。
    • 我从你上次的更新中注意到“setClock”和“setControllerClock”的分离仍然存在，所以我回到我原来的python程序，发现我没有在方法时调整方法名称从集群转移到控制器！
    猜你喜欢
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 2015-06-20
    • 2023-03-14
    • 2014-08-23
    • 2014-06-10
    相关资源
    最近更新 更多
    热门标签
    Java Python linux javascript Mysql C# Docker 算法 前端 SpringBoot Redis Vue spring 设计模式 .net core .net kubernetes c++ 数据库 数据结构 大数据 js 机器学习 微服务 Android Go 程序员 面试 JVM ASP.net core 云原生 人工智能 后端 PHP git CSS golang k8s Nginx Django mybatis 深度学习 多线程 React 架构 devops 爬虫 云计算 Spring Boot LeetCode