diff options
| -rw-r--r-- | Objects/listobject.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/Objects/listobject.c b/Objects/listobject.c index bfa3b79..e2b9b2b 100644 --- a/Objects/listobject.c +++ b/Objects/listobject.c @@ -760,9 +760,9 @@ reverse_slice(PyObject **lo, PyObject **hi) */ /* Comparison function. Takes care of calling a user-supplied - * comparison function (any callable Python object). Calls the - * standard comparison function, PyObject_RichCompareBool(), if the user- - * supplied function is NULL. + * comparison function (any callable Python object), which must not be + * NULL (use the ISLT macro if you don't know, or call PyObject_RichCompareBool + * with Py_LT if you know it's NULL). * Returns -1 on error, 1 if x < y, 0 if x >= y. */ static int @@ -772,9 +772,7 @@ islt(PyObject *x, PyObject *y, PyObject *compare) PyObject *args; int i; - if (compare == NULL) - return PyObject_RichCompareBool(x, y, Py_LT); - + assert(compare != NULL); /* Call the user's comparison function and translate the 3-way * result into true or false (or error). */ @@ -800,11 +798,20 @@ islt(PyObject *x, PyObject *y, PyObject *compare) return i < 0; } -/* Compare X to Y via islt(). Goto "fail" if the comparison raises an +/* If COMPARE is NULL, calls PyObject_RichCompareBool with Py_LT, else calls + * islt. This avoids a layer of function call in the usual case, and + * sorting does many comparisons. + * Returns -1 on error, 1 if x < y, 0 if x >= y. + */ +#define ISLT(X, Y, COMPARE) ((COMPARE) == NULL ? \ + PyObject_RichCompareBool(X, Y, Py_LT) : \ + islt(X, Y, COMPARE)) + +/* Compare X to Y via "<". Goto "fail" if the comparison raises an error. Else "k" is set to true iff X<Y, and an "if (k)" block is started. It makes more sense in context <wink>. X and Y are PyObject*s. */ -#define IFLT(X, Y) if ((k = islt(X, Y, compare)) < 0) goto fail; \ +#define IFLT(X, Y) if ((k = ISLT(X, Y, compare)) < 0) goto fail; \ if (k) /* binarysort is the best method for sorting small arrays: it does @@ -1241,7 +1248,7 @@ merge_lo(MergeState *ms, PyObject **pa, int na, PyObject **pb, int nb) * appears to win consistently. */ for (;;) { - k = islt(*pb, *pa, compare); + k = ISLT(*pb, *pa, compare); if (k) { if (k < 0) goto Fail; @@ -1369,7 +1376,7 @@ merge_hi(MergeState *ms, PyObject **pa, int na, PyObject **pb, int nb) * appears to win consistently. */ for (;;) { - k = islt(*pb, *pa, compare); + k = ISLT(*pb, *pa, compare); if (k) { if (k < 0) goto Fail; @@ -1683,6 +1690,7 @@ fail: return result; } #undef IFLT +#undef ISLT int PyList_Sort(PyObject *v) |