At Fri, 13 Aug 2010 09:25:22 -0500, Brian Ray wrote:
Hello:
I think I am experience a build problem here but not really sure; nonetheless, below is a simple example that illustrates my problem.
I don't think it's a build issue.
Any idea what I might be doing wrong. I am using boost_1_43_0 built with gcc 4.2.1 on i686 running darwin. I am linking to the standard 2.5 python that comes with the distro.
Please note that the PyRun_SimpleString("import sys"); does not error at all. The error comes from when the call to import(). I am not sure if this is a clue or not but gdb seems not to know what line it is on. I am guessing it is just confused because of all the inlines. I suspect this is a linking issues of some sort. However I did check that they are all linking to the correct location. Why does it convert the const char * to a str in the first place. ^^^^^
So that it can call Python's import function.
Seems to be thrashing around a bit.
-- Brian
/// contents of boost_python_issue.cpp #include
using namespace boost::python; int main(int argc, char **argv) { Py_Initialize(); try { PyRun_SimpleString("import sys"); // This raises exception object sys = import("sys"); } catch (boost::python::error_already_set) { PyErr_Print(); } Py_Finalize(); }
Hmm, looks simple enough.
Output from gdb:
(gdb) break main Breakpoint 1 at 0x100001319: file boost_python_issue.cpp, line 9. (gdb) r Starting program: /Project/zephyr/src/Composer/boost_python_issue Reading symbols for shared libraries .++++++++..... done
Breakpoint 1, main (argc=1, argv=0x7fff5fbff6d8) at boost_python_issue.cpp:9 9 Py_Initialize(); (gdb) s 11 PyRun_SimpleString("import sys"); (gdb) 13 object sys = import("sys"); (gdb) boost::python::str::str (this=0x7fff5fbff690, s=0x10000169d "sys") at str.hpp:150 150 str(const char* s) : base(s) {} // new str (gdb) boost::python::detail::str_base::str_base (this=0x7fff5fbff690, s=0x10000169d "sys") at libs/python/src/str.cpp:39 39 )) (gdb) object [inlined] () at /Users/bray/sources/boost_1_43_0/boost/python/object_core.hpp:534 Line number 534 out of range; errors.hpp has 55 lines. (gdb) expect_non_null<PyObject> [inlined] () at /Users/bray/sources/boost_1_43_0/boost/python/errors.hpp:43 44 if (x == 0) (gdb) object [inlined] () at /Users/bray/sources/boost_1_43_0/boost/python/object_core.hpp:513 534 : object_base(expect_non_null((PyObject*)p)) (gdb) object_base [inlined] () at /Users/bray/sources/boost_1_43_0/boost/python/object_core.hpp:513 513 : m_ptr(p) (gdb) boost::python::detail::str_base::str_base (this=0x7fff5fbff690, s=
) at libs/python/src/str.cpp:40 40 {} (gdb) 0x000000010000154d in boost::python::str::str (this=0x7fff5fbff690, s=0x10000169d "sys") at str.hpp:150 150 str(const char* s) : base(s) {} // new str (gdb) boost::python::import (name=@0x7fff5fbff690) at libs/python/src/import.cpp:19 19 char *n = python::extract (name);
This is where the bug is (in Boost.Python). One should never try to extract a pointer to non-const char from a str. Could you try the enclosed patch and see if your problem is fixed? -- Dave Abrahams BoostPro Computing http://www.boostpro.com