From 83a204e6951c6358f995da3b60dd61224e9d41ac Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Tue, 5 Mar 2019 14:13:17 +0000 Subject: [PATCH] pygrub/fsimage: make it work with python 3 With the help of two porting guides and cpython source code: 1. Use PyBytes to replace PyString counterparts. 2. Use PyVarObject_HEAD_INIT. 3. Remove usage of Py_FindMethod. 4. Use new module initialisation routine. For #3, Py_FindMethod was removed, yet an alternative wasn't documented. The code is the result of reverse-engineering cpython commit 6116d4a1d1 https://docs.python.org/3/howto/cporting.html http://python3porting.com/cextensions.html Signed-off-by: Wei Liu Reviewed-by: Andrew Cooper --- tools/pygrub/src/fsimage/fsimage.c | 123 ++++++++++++++++------------- 1 file changed, 69 insertions(+), 54 deletions(-) diff --git a/tools/pygrub/src/fsimage/fsimage.c b/tools/pygrub/src/fsimage/fsimage.c index 780207791c..2ebbbe35df 100644 --- a/tools/pygrub/src/fsimage/fsimage.c +++ b/tools/pygrub/src/fsimage/fsimage.c @@ -26,12 +26,6 @@ #include #include -#if (PYTHON_API_VERSION >= 1011) -#define PY_PAD 0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L,0L -#else -#define PY_PAD 0L,0L,0L,0L -#endif - typedef struct fsimage_fs { PyObject_HEAD fsi_t *fs; @@ -59,12 +53,24 @@ fsimage_file_read(fsimage_file_t *file, PyObject *args, PyObject *kwargs) bufsize = size ? size : 4096; - if ((buffer = PyString_FromStringAndSize(NULL, bufsize)) == NULL) + buffer = +#if PY_MAJOR_VERSION < 3 + PyString_FromStringAndSize(NULL, bufsize); +#else + PyBytes_FromStringAndSize(NULL, bufsize); +#endif + + if (buffer == NULL) return (NULL); while (1) { int err; - void *buf = PyString_AS_STRING(buffer) + bytesread; + void *buf = +#if PY_MAJOR_VERSION < 3 + PyString_AS_STRING(buffer) + bytesread; +#else + PyBytes_AS_STRING(buffer) + bytesread; +#endif err = fsi_pread_file(file->file, buf, bufsize, bytesread + offset); @@ -84,12 +90,20 @@ fsimage_file_read(fsimage_file_t *file, PyObject *args, PyObject *kwargs) if (bufsize == 0) break; } else { +#if PY_MAJOR_VERSION < 3 if (_PyString_Resize(&buffer, bytesread + bufsize) < 0) +#else + if (_PyBytes_Resize(&buffer, bytesread + bufsize) < 0) +#endif return (NULL); } } +#if PY_MAJOR_VERSION < 3 _PyString_Resize(&buffer, bytesread); +#else + _PyBytes_Resize(&buffer, bytesread); +#endif return (buffer); } @@ -106,11 +120,13 @@ static struct PyMethodDef fsimage_file_methods[] = { { NULL, NULL, 0, NULL } }; +#if PY_MAJOR_VERSION < 3 static PyObject * fsimage_file_getattr(fsimage_file_t *file, char *name) { return (Py_FindMethod(fsimage_file_methods, (PyObject *)file, name)); } +#endif static void fsimage_file_dealloc(fsimage_file_t *file) @@ -123,29 +139,18 @@ fsimage_file_dealloc(fsimage_file_t *file) static char fsimage_file_type__doc__[] = "Filesystem image file"; PyTypeObject fsimage_file_type = { - PyObject_HEAD_INIT(&PyType_Type) - 0, /* ob_size */ - "xenfsimage.file", /* tp_name */ - sizeof(fsimage_file_t), /* tp_size */ - 0, /* tp_itemsize */ - (destructor) fsimage_file_dealloc, /* tp_dealloc */ - 0, /* tp_print */ - (getattrfunc) fsimage_file_getattr, /* tp_getattr */ - 0, /* tp_setattr */ - 0, /* tp_compare */ - 0, /* tp_repr */ - 0, /* tp_as_number */ - 0, /* tp_as_sequence */ - 0, /* tp_as_mapping */ - 0, /* tp_hash */ - 0, /* tp_call */ - 0, /* tp_str */ - 0, /* tp_getattro */ - 0, /* tp_setattro */ - 0, /* tp_as_buffer */ - Py_TPFLAGS_DEFAULT, /* tp_flags */ - fsimage_file_type__doc__, - PY_PAD + PyVarObject_HEAD_INIT(&PyType_Type, 0) + .tp_name = "xenfsimage.file", + .tp_basicsize = sizeof(fsimage_file_t), + .tp_dealloc = (destructor) fsimage_file_dealloc, +#if PY_MAJOR_VERSION < 3 + .tp_getattr = (getattrfunc) fsimage_file_getattr, +#endif + .tp_flags = Py_TPFLAGS_DEFAULT, + .tp_doc = fsimage_file_type__doc__, +#if PY_MAJOR_VERSION >= 3 + .tp_methods = fsimage_file_methods, +#endif }; static PyObject * @@ -208,11 +213,13 @@ static struct PyMethodDef fsimage_fs_methods[] = { { NULL, NULL, 0, NULL } }; +#if PY_MAJOR_VERSION < 3 static PyObject * fsimage_fs_getattr(fsimage_fs_t *fs, char *name) { return (Py_FindMethod(fsimage_fs_methods, (PyObject *)fs, name)); } +#endif static void fsimage_fs_dealloc (fsimage_fs_t *fs) @@ -225,29 +232,18 @@ fsimage_fs_dealloc (fsimage_fs_t *fs) PyDoc_STRVAR(fsimage_fs_type__doc__, "Filesystem image"); PyTypeObject fsimage_fs_type = { - PyObject_HEAD_INIT(&PyType_Type) - 0, /* ob_size */ - "xenfsimage.fs", /* tp_name */ - sizeof(fsimage_fs_t), /* tp_size */ - 0, /* tp_itemsize */ - (destructor) fsimage_fs_dealloc, /* tp_dealloc */ - 0, /* tp_print */ - (getattrfunc) fsimage_fs_getattr, /* tp_getattr */ - 0, /* tp_setattr */ - 0, /* tp_compare */ - 0, /* tp_repr */ - 0, /* tp_as_number */ - 0, /* tp_as_sequence */ - 0, /* tp_as_mapping */ - 0, /* tp_hash */ - 0, /* tp_call */ - 0, /* tp_str */ - 0, /* tp_getattro */ - 0, /* tp_setattro */ - 0, /* tp_as_buffer */ - Py_TPFLAGS_DEFAULT, /* tp_flags */ - fsimage_fs_type__doc__, - PY_PAD + PyVarObject_HEAD_INIT(&PyType_Type, 0) + .tp_name = "xenfsimage.fs", + .tp_basicsize = sizeof(fsimage_fs_t), + .tp_dealloc = (destructor) fsimage_fs_dealloc, +#if PY_MAJOR_VERSION < 3 + .tp_getattr = (getattrfunc) fsimage_fs_getattr, +#endif + .tp_flags = Py_TPFLAGS_DEFAULT, + .tp_doc = fsimage_fs_type__doc__, +#if PY_MAJOR_VERSION >= 3 + .tp_methods = fsimage_fs_methods, +#endif }; static PyObject * @@ -309,8 +305,27 @@ static struct PyMethodDef fsimage_module_methods[] = { { NULL, NULL, 0, NULL } }; +#if PY_MAJOR_VERSION >= 3 +static struct PyModuleDef fsimage_module_def = { + PyModuleDef_HEAD_INIT, + .m_name = "xenfsimage", + .m_size = -1, + .m_methods = fsimage_module_methods, +}; +#endif + PyMODINIT_FUNC +#if PY_MAJOR_VERSION >= 3 +PyInit_xenfsimage(void) +#else initxenfsimage(void) +#endif { +#if PY_MAJOR_VERSION < 3 Py_InitModule("xenfsimage", fsimage_module_methods); +#else + if (PyType_Ready(&fsimage_fs_type) < 0 || PyType_Ready(&fsimage_file_type) < 0) + return NULL; + return PyModule_Create(&fsimage_module_def); +#endif } -- 2.17.1