BLD: fix build warnings

pandas/_libs/join.pyx

@@ -1,5 +1,5 @@
 import cython
-from cython import Py_ssize_t
+from cython import Py_ssize_t, size_t
 
 import numpy as np
 cimport numpy as cnp
@@ -119,7 +119,8 @@ def left_outer_join(const int64_t[:] left, const int64_t[:] right,
     right_indexer = _get_result_indexer(right_sorter, right_indexer)
 
     if not sort:  # if not asked to sort, revert to original order
-        if len(left) == len(left_indexer):
+        # cast to avoid build warning
+        if len(left) == <size_t>len(left_indexer):
             # no multiple matches for any row on the left
             # this is a short-cut to avoid groupsort_indexer
             # otherwise, the `else` path also works in this case

pandas/_libs/ops.pyx

@@ -4,7 +4,7 @@ from cpython cimport (PyObject_RichCompareBool,
                       Py_EQ, Py_NE, Py_LT, Py_LE, Py_GT, Py_GE)
 
 import cython
-from cython import Py_ssize_t
+from cython import Py_ssize_t, size_t
 
 import numpy as np
 from numpy cimport ndarray, uint8_t, import_array
@@ -118,7 +118,7 @@ def vec_compare(object[:] left, object[:] right, object op):
     result : ndarray[bool]
     """
     cdef:
-        Py_ssize_t i, n = len(left)
+        size_t i, n = len(left)
         ndarray[uint8_t, cast=True] result
         int flag
 
@@ -220,7 +220,7 @@ def vec_binop(object[:] left, object[:] right, object op):
     result : ndarray[object]
     """
     cdef:
-        Py_ssize_t i, n = len(left)
+        size_t i, n = len(left)
         object[:] result
 
     if n != len(right):

pandas/_libs/tslibs/parsing.pyx

@@ -8,6 +8,7 @@ from io import StringIO
 from libc.string cimport strchr
 
 import cython
+from cython import size_t, Py_ssize_t
 
 from cpython cimport PyObject_Str, PyUnicode_Join
 
@@ -603,7 +604,7 @@ def try_parse_date_and_time(object[:] dates, object[:] times,
                             date_parser=None, time_parser=None,
                             dayfirst=False, default=None):
     cdef:
-        Py_ssize_t i, n
+        size_t i, n
         object[:] result
 
     n = len(dates)
@@ -639,7 +640,7 @@ def try_parse_date_and_time(object[:] dates, object[:] times,
 def try_parse_year_month_day(object[:] years, object[:] months,
                              object[:] days):
     cdef:
-        Py_ssize_t i, n
+        size_t i, n
         object[:] result
 
     n = len(years)
@@ -661,7 +662,7 @@ def try_parse_datetime_components(object[:] years,
                                   object[:] seconds):
 
     cdef:
-        Py_ssize_t i, n
+        size_t i, n
         object[:] result
         int secs
         double float_secs

pandas/_libs/window.pyx

@@ -1,7 +1,7 @@
 # cython: boundscheck=False, wraparound=False, cdivision=True
 
 import cython
-from cython import Py_ssize_t
+from cython import Py_ssize_t, size_t
 from libcpp.deque cimport deque
 
 from libc.stdlib cimport malloc, free
@@ -1821,7 +1821,7 @@ def ewmcov(float64_t[:] input_x, float64_t[:] input_y,
     """
 
     cdef:
-        Py_ssize_t N = len(input_x)
+        size_t N = len(input_x)
         float64_t alpha, old_wt_factor, new_wt, mean_x, mean_y, cov
         float64_t sum_wt, sum_wt2, old_wt, cur_x, cur_y, old_mean_x, old_mean_y
         Py_ssize_t i, nobs

pandas/io/sas/sas.pyx

@@ -1,5 +1,6 @@
 # cython: profile=False
 # cython: boundscheck=False, initializedcheck=False
+from cython import size_t
 
 import numpy as np
 import pandas.io.sas.sas_constants as const
@@ -18,8 +19,9 @@ cdef const uint8_t[:] rle_decompress(int result_length,
     cdef:
         uint8_t control_byte, x
         uint8_t[:] result = np.zeros(result_length, np.uint8)
-        int rpos = 0, ipos = 0, length = len(inbuff)
+        int rpos = 0
         int i, nbytes, end_of_first_byte
+        size_t ipos = 0, length = len(inbuff)
 
     while ipos < length:
         control_byte = inbuff[ipos] & 0xF0
@@ -123,8 +125,9 @@ cdef const uint8_t[:] rdc_decompress(int result_length,
     cdef:
         uint8_t cmd
         uint16_t ctrl_bits, ctrl_mask = 0, ofs, cnt
-        int ipos = 0, rpos = 0, k
+        int rpos = 0, k
         uint8_t[:] outbuff = np.zeros(result_length, dtype=np.uint8)
+        size_t ipos = 0
 
     ii = -1