PyString_FromStringAndSize导致段错误

Question

我有一个奇怪的段错误与python。这里是有问题的代码：

const std::string &fullName = child.getFullName(); 
const char *fName = fullName.c_str(); 
const int len = fullName.size(); 

printf(":: %02d --> %s\n", len, fName); 

PyObject *item = PyString_FromStringAndSize(fName, len); 
PyList_Append(list, item); 

我把printf的那里，希望能得到一个提示。但长度和fName值是正确的。那里没有空值！

下面是我从GDB得到跟踪：

#0 0x0000000000423e00 in PyObject_Malloc() 
#1 0x0000000000513a3f in PyString_FromStringAndSize() 
#2 0x00007ffff554aa5e in recurseObject (list=0x9f5f38, obj=...) 
    at file.cpp:59 
#3 0x00007ffff554aa74 in recurseObject (list=0x9f5f38, obj=...) 
    at file.cpp:62 
#4 0x00007ffff554aa74 in recurseObject (list=0x9f5f38, obj=...) 
    at file.cpp:62 
#5 0x00007ffff554ad27 in listObjects (self=<optimized out>, args=<optimized out>) 
    at file.cpp:73 

任何想法？我试图环顾四周，但我无法找到关于该主题的任何准确信息。

编辑：只是为这个问题添加更多的模糊性。只有当我在脚本中使用它时才会出现此错误。当我从命令行调用Python时，一切正常！

编辑：这里是我的valgrind从获得：

==27681== Invalid read of size 8 
==27681== at 0x423E00: PyObject_Malloc (in /usr/bin/python2.7) 
==27681== by 0x513A3E: PyString_FromStringAndSize (in /usr/bin/python2.7) 
==27681== by 0x7953DB4: recurseObjectChildren(_object*, Alembic::Abc::v4::IObject const&) (iarchive.cpp:55) 
==27681== by 0x7953DCA: recurseObjectChildren(_object*, Alembic::Abc::v4::IObject const&) (iarchive.cpp:58) 
==27681== by 0x7953DCA: recurseObjectChildren(_object*, Alembic::Abc::v4::IObject const&) (iarchive.cpp:58) 
==27681== by 0x7953F26: iArchive_getIdentifiers(_object*, _object*) (iarchive.cpp:69) 
==27681== by 0x498909: PyEval_EvalFrameEx (in /usr/bin/python2.7) 
==27681== by 0x498601: PyEval_EvalFrameEx (in /usr/bin/python2.7) 
==27681== by 0x498601: PyEval_EvalFrameEx (in /usr/bin/python2.7) 
==27681== by 0x49F1BF: PyEval_EvalCodeEx (in /usr/bin/python2.7) 
==27681== by 0x4A9080: PyRun_FileExFlags (in /usr/bin/python2.7) 
==27681== by 0x4A9310: PyRun_SimpleFileExFlags (in /usr/bin/python2.7) 
==27681== Address 0xffffffffffffff00 is not stack'd, malloc'd or (recently) free'd 
==27681== 
==27681== 
==27681== Process terminating with default action of signal 11 (SIGSEGV) 
==27681== Access not within mapped region at address 0xFFFFFFFFFFFFFF00 
==27681== at 0x423E00: PyObject_Malloc (in /usr/bin/python2.7) 
==27681== by 0x513A3E: PyString_FromStringAndSize (in /usr/bin/python2.7) 
==27681== by 0x7953DB4: recurseObjectChildren(_object*, Alembic::Abc::v4::IObject const&) (iarchive.cpp:55) 
==27681== by 0x7953DCA: recurseObjectChildren(_object*, Alembic::Abc::v4::IObject const&) (iarchive.cpp:58) 
==27681== by 0x7953DCA: recurseObjectChildren(_object*, Alembic::Abc::v4::IObject const&) (iarchive.cpp:58) 
==27681== by 0x7953F26: iArchive_getIdentifiers(_object*, _object*) (iarchive.cpp:69) 
==27681== by 0x498909: PyEval_EvalFrameEx (in /usr/bin/python2.7) 
==27681== by 0x498601: PyEval_EvalFrameEx (in /usr/bin/python2.7) 
==27681== by 0x498601: PyEval_EvalFrameEx (in /usr/bin/python2.7) 
==27681== by 0x49F1BF: PyEval_EvalCodeEx (in /usr/bin/python2.7) 
==27681== by 0x4A9080: PyRun_FileExFlags (in /usr/bin/python2.7) 
==27681== by 0x4A9310: PyRun_SimpleFileExFlags (in /usr/bin/python2.7) 
==27681== If you believe this happened as a result of a stack 
==27681== overflow in your program's main thread (unlikely but 
==27681== possible), you can try to increase the size of the 
==27681== main thread stack using the --main-stacksize= flag. 
==27681== The main thread stack size used in this run was 8388608. 
==27681== 
==27681== HEAP SUMMARY: 
==27681==  in use at exit: 5,126,103 bytes in 5,336 blocks 
==27681== total heap usage: 14,574 allocs, 9,238 frees, 12,498,954 bytes allocated 
==27681== LEAK SUMMARY: 
==27681== definitely lost: 76 bytes in 3 blocks 
==27681== indirectly lost: 240 bytes in 10 blocks 
==27681==  possibly lost: 671,180 bytes in 1,124 blocks 
==27681== still reachable: 4,454,607 bytes in 4,199 blocks 
==27681==   suppressed: 0 bytes in 0 blocks 
==27681== Reachable blocks (those to which a pointer was found) are not shown. 
==27681== To see them, rerun with: --leak-check=full --show-reachable=yes 

不能确定这是什么意思！我仍然不明白为什么它会失败。我尝试了不同的方法，如克隆字符串fullName以确保分配了新的内存。甚至使用了一个新的char []并在其中复制全名。仍然是同一个问题，在同一个地方。

任何想法的人？ Python在Python中很普遍吗？

Answer 1

我不知道如何解释这一点，但这是肯定的原因，因为这堆在之前的某个地方已经被破坏了。所以我设法追踪错误的来源。

FTW：是这样的：

Bob bob; 
new (&bob) Bob(someParameter); 

可能不是超级安全！在某些情况下，它是完美的，但不是无处不在。