From b2a5be0763ee572bed431335eb4712fac94f5a7b Mon Sep 17 00:00:00 2001 From: Serhiy Storchaka Date: Wed, 25 Jan 2017 13:23:05 +0200 Subject: [PATCH] Issue #27867: Function PySlice_GetIndicesEx() is replaced with a macro if Py_LIMITED_API is not set or set to the value between 0x03050400 and 0x03060000 (not including) or 0x03060100 or higher. --- Include/sliceobject.h | 16 +++++++-- Misc/NEWS | 4 +++ Objects/sliceobject.c | 78 ++++++++++++++++++++++++++++++------------- PC/python3.def | 2 ++ 4 files changed, 74 insertions(+), 26 deletions(-) diff --git a/Include/sliceobject.h b/Include/sliceobject.h index 26370e01757..53593690126 100644 --- a/Include/sliceobject.h +++ b/Include/sliceobject.h @@ -41,8 +41,20 @@ PyAPI_FUNC(int) _PySlice_GetLongIndices(PySliceObject *self, PyObject *length, PyAPI_FUNC(int) PySlice_GetIndices(PyObject *r, Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step); PyAPI_FUNC(int) PySlice_GetIndicesEx(PyObject *r, Py_ssize_t length, - Py_ssize_t *start, Py_ssize_t *stop, - Py_ssize_t *step, Py_ssize_t *slicelength); + Py_ssize_t *start, Py_ssize_t *stop, + Py_ssize_t *step, Py_ssize_t *slicelength); + +#if !defined(Py_LIMITED_API) || (Py_LIMITED_API+0 >= 0x03050400 && Py_LIMITED_API+0 < 0x03060000) || Py_LIMITED_API+0 >= 0x03060100 +#define PySlice_GetIndicesEx(slice, length, start, stop, step, slicelen) ( \ + PySlice_Unpack((slice), (start), (stop), (step)) < 0 ? -1 : \ + ((*slicelen = PySlice_AdjustIndices((length), (start), (stop), *(step))), \ + 0)) +PyAPI_FUNC(int) PySlice_Unpack(PyObject *slice, + Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step); +PyAPI_FUNC(Py_ssize_t) PySlice_AdjustIndices(Py_ssize_t length, + Py_ssize_t *start, Py_ssize_t *stop, + Py_ssize_t step); +#endif #ifdef __cplusplus } diff --git a/Misc/NEWS b/Misc/NEWS index eb79d5c96f9..6ad85d53232 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -40,6 +40,10 @@ Library C API ----- +- Issue #27867: Function PySlice_GetIndicesEx() is replaced with a macro if + Py_LIMITED_API is not set or set to the value between 0x03050400 + and 0x03060000 (not including) or 0x03060100 or higher. + - Issue #29083: Fixed the declaration of some public API functions. PyArg_VaParse() and PyArg_VaParseTupleAndKeywords() were not available in limited API. PyArg_ValidateKeywordArguments(), PyArg_UnpackTuple() and diff --git a/Objects/sliceobject.c b/Objects/sliceobject.c index 2f32355cd25..6a690213d14 100644 --- a/Objects/sliceobject.c +++ b/Objects/sliceobject.c @@ -191,15 +191,12 @@ PySlice_GetIndices(PyObject *_r, Py_ssize_t length, } int -PySlice_GetIndicesEx(PyObject *_r, Py_ssize_t length, - Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step, - Py_ssize_t *slicelength) +PySlice_Unpack(PyObject *_r, + Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step) { PySliceObject *r = (PySliceObject*)_r; /* this is harder to get right than you might think */ - Py_ssize_t defstart, defstop; - if (r->step == Py_None) { *step = 1; } @@ -219,42 +216,75 @@ PySlice_GetIndicesEx(PyObject *_r, Py_ssize_t length, *step = -PY_SSIZE_T_MAX; } - defstart = *step < 0 ? length-1 : 0; - defstop = *step < 0 ? -1 : length; - if (r->start == Py_None) { - *start = defstart; + *start = *step < 0 ? PY_SSIZE_T_MAX-1 : 0;; } else { if (!_PyEval_SliceIndex(r->start, start)) return -1; - if (*start < 0) *start += length; - if (*start < 0) *start = (*step < 0) ? -1 : 0; - if (*start >= length) - *start = (*step < 0) ? length - 1 : length; } if (r->stop == Py_None) { - *stop = defstop; + *stop = *step < 0 ? -PY_SSIZE_T_MAX : PY_SSIZE_T_MAX; } else { if (!_PyEval_SliceIndex(r->stop, stop)) return -1; - if (*stop < 0) *stop += length; - if (*stop < 0) *stop = (*step < 0) ? -1 : 0; - if (*stop >= length) - *stop = (*step < 0) ? length - 1 : length; } - if ((*step < 0 && *stop >= *start) - || (*step > 0 && *start >= *stop)) { - *slicelength = 0; + return 0; +} + +Py_ssize_t +PySlice_AdjustIndices(Py_ssize_t length, + Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t step) +{ + /* this is harder to get right than you might think */ + + assert(step != 0); + assert(step >= -PY_SSIZE_T_MAX); + + if (*start < 0) { + *start += length; + if (*start < 0) { + *start = (step < 0) ? -1 : 0; + } } - else if (*step < 0) { - *slicelength = (*stop-*start+1)/(*step)+1; + else if (*start >= length) { + *start = (step < 0) ? length - 1 : length; + } + + if (*stop < 0) { + *stop += length; + if (*stop < 0) { + *stop = (step < 0) ? -1 : 0; + } + } + else if (*stop >= length) { + *stop = (step < 0) ? length - 1 : length; + } + + if (step < 0) { + if (*stop < *start) { + return (*start - *stop - 1) / (-step) + 1; + } } else { - *slicelength = (*stop-*start-1)/(*step)+1; + if (*start < *stop) { + return (*stop - *start - 1) / step + 1; + } } + return 0; +} +#undef PySlice_GetIndicesEx + +int +PySlice_GetIndicesEx(PyObject *_r, Py_ssize_t length, + Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step, + Py_ssize_t *slicelength) +{ + if (PySlice_Unpack(_r, start, stop, step) < 0) + return -1; + *slicelength = PySlice_AdjustIndices(length, start, stop, *step); return 0; } diff --git a/PC/python3.def b/PC/python3.def index d7530494df7..200d6bb7e29 100644 --- a/PC/python3.def +++ b/PC/python3.def @@ -527,10 +527,12 @@ EXPORTS PySet_Pop=python35.PySet_Pop PySet_Size=python35.PySet_Size PySet_Type=python35.PySet_Type DATA + PySlice_AdjustIndices=python35.PySlice_AdjustIndices PySlice_GetIndices=python35.PySlice_GetIndices PySlice_GetIndicesEx=python35.PySlice_GetIndicesEx PySlice_New=python35.PySlice_New PySlice_Type=python35.PySlice_Type DATA + PySlice_Unpack=python35.PySlice_Unpack PySortWrapper_Type=python35.PySortWrapper_Type DATA PyState_AddModule=python35.PyState_AddModule PyState_FindModule=python35.PyState_FindModule