我对 python 有一个奇怪的段错误。这是有问题的代码:
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 放在那里,希望得到提示。但是长度和 fName 值是正确的。那里没有空值!
这是我从 gdb 获得的跟踪信息:
#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
任何的想法 ?我试着环顾四周,但找不到关于这个主题的任何确切信息。
编辑:只是为了给这个问题增加更多的模糊性。仅当我在脚本中使用它时才会出现此错误。当我在 Python 中从命令行调用它时,一切正常!
编辑:这是我从 valgrind 得到的:
==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
不太清楚这意味着什么!而且我仍然不明白为什么它在那里失败。我尝试了不同的方法,例如克隆字符串 fullName 以确保它是分配的新内存。甚至使用了新的 char[] 并在其中复制了全名。还是同样的问题,在同一个地方。
有人知道吗?它在 Python 中很常见吗?