Make memoryviews work with cache_builtins=False (GH-3415)

Now they make their own tiny cache of the relevant exceptions at module initialization so they can still access these without the GIL.

closes https://github.com/cython/cython/issues/3406

Cython/Utility/MemoryView.pyx

@@ -8,8 +8,12 @@ cimport cython
 
 # from cpython cimport ...
 cdef extern from "Python.h":
+    ctypedef struct PyObject
     int PyIndex_Check(object)
     object PyLong_FromVoidPtr(void *)
+    PyObject *PyExc_IndexError
+    PyObject *PyExc_ValueError
+    PyObject *PyExc_MemoryError
 
 cdef extern from "pythread.h":
     ctypedef void *PyThread_type_lock
@@ -94,9 +98,6 @@ cdef extern from "<stdlib.h>":
     void free(void *) nogil
     void *memcpy(void *dest, void *src, size_t n) nogil
 
-
-
-
 #
 ### cython.array class
 #
@@ -829,13 +830,13 @@ cdef int slice_memviewslice(
         if start < 0:
             start += shape
         if not 0 <= start < shape:
-            _err_dim(IndexError, "Index out of bounds (axis %d)", dim)
+            _err_dim(PyExc_IndexError, "Index out of bounds (axis %d)", dim)
     else:
         # index is a slice
         negative_step = have_step != 0 and step < 0
 
         if have_step and step == 0:
-            _err_dim(ValueError, "Step may not be zero (axis %d)", dim)
+            _err_dim(PyExc_ValueError, "Step may not be zero (axis %d)", dim)
 
         # check our bounds and set defaults
         if have_start:
@@ -896,7 +897,7 @@ cdef int slice_memviewslice(
             if new_ndim == 0:
                 dst.data = (<char **> dst.data)[0] + suboffset
             else:
-                _err_dim(IndexError, "All dimensions preceding dimension %d "
+                _err_dim(PyExc_IndexError, "All dimensions preceding dimension %d "
                                      "must be indexed and not sliced", dim)
         else:
             suboffset_dim[0] = new_ndim
@@ -954,7 +955,7 @@ cdef int transpose_memslice({{memviewslice_name}} *memslice) nogil except 0:
         shape[i], shape[j] = shape[j], shape[i]
 
         if memslice.suboffsets[i] >= 0 or memslice.suboffsets[j] >= 0:
-            _err(ValueError, "Cannot transpose memoryview with indirect dimensions")
+            _err(PyExc_ValueError, "Cannot transpose memoryview with indirect dimensions")
 
     return 1
 
@@ -1221,7 +1222,7 @@ cdef void *copy_data_to_temp({{memviewslice_name}} *src,
 
     result = malloc(size)
     if not result:
-        _err(MemoryError, NULL)
+        _err(PyExc_MemoryError, NULL)
 
     # tmpslice[0] = src
     tmpslice.data = <char *> result
@@ -1254,15 +1255,15 @@ cdef int _err_extents(int i, Py_ssize_t extent1,
                                                         (i, extent1, extent2))
 
 @cname('__pyx_memoryview_err_dim')
-cdef int _err_dim(object error, char *msg, int dim) except -1 with gil:
-    raise error(msg.decode('ascii') % dim)
+cdef int _err_dim(PyObject *error, char *msg, int dim) except -1 with gil:
+    raise (<object>error)(msg.decode('ascii') % dim)
 
 @cname('__pyx_memoryview_err')
-cdef int _err(object error, char *msg) except -1 with gil:
+cdef int _err(PyObject *error, char *msg) except -1 with gil:
     if msg != NULL:
-        raise error(msg.decode('ascii'))
+        raise (<object>error)(msg.decode('ascii'))
     else:
-        raise error
+        raise (<object>error)
 
 @cname('__pyx_memoryview_copy_contents')
 cdef int memoryview_copy_contents({{memviewslice_name}} src,
@@ -1297,7 +1298,7 @@ cdef int memoryview_copy_contents({{memviewslice_name}} src,
                 _err_extents(i, dst.shape[i], src.shape[i])
 
         if src.suboffsets[i] >= 0:
-            _err_dim(ValueError, "Dimension %d is not direct", i)
+            _err_dim(PyExc_ValueError, "Dimension %d is not direct", i)
 
     if slices_overlap(&src, &dst, ndim, itemsize):
         # slices overlap, copy to temp, copy temp to dst

tests/compile/fused_redeclare_T3111.pyx

@@ -24,16 +24,16 @@ def foo(dtype_t[:] a, dtype_t_out[:, :] b):
 _WARNINGS = """
 22:10: 'cpdef_method' redeclared
 33:10: 'cpdef_cname_method' redeclared
-446:72: Argument evaluation order in C function call is undefined and may not be as expected
-446:72: Argument evaluation order in C function call is undefined and may not be as expected
-749:34: Argument evaluation order in C function call is undefined and may not be as expected
-749:34: Argument evaluation order in C function call is undefined and may not be as expected
-943:27: Ambiguous exception value, same as default return value: 0
-943:27: Ambiguous exception value, same as default return value: 0
-974:29: Ambiguous exception value, same as default return value: 0
-974:29: Ambiguous exception value, same as default return value: 0
-1002:46: Ambiguous exception value, same as default return value: 0
-1002:46: Ambiguous exception value, same as default return value: 0
-1092:29: Ambiguous exception value, same as default return value: 0
-1092:29: Ambiguous exception value, same as default return value: 0
+447:72: Argument evaluation order in C function call is undefined and may not be as expected
+447:72: Argument evaluation order in C function call is undefined and may not be as expected
+750:34: Argument evaluation order in C function call is undefined and may not be as expected
+750:34: Argument evaluation order in C function call is undefined and may not be as expected
+944:27: Ambiguous exception value, same as default return value: 0
+944:27: Ambiguous exception value, same as default return value: 0
+975:29: Ambiguous exception value, same as default return value: 0
+975:29: Ambiguous exception value, same as default return value: 0
+1003:46: Ambiguous exception value, same as default return value: 0
+1003:46: Ambiguous exception value, same as default return value: 0
+1093:29: Ambiguous exception value, same as default return value: 0
+1093:29: Ambiguous exception value, same as default return value: 0
 """

tests/memoryview/memoryview_cache_builtins.srctree

+PYTHON setup.py build_ext --inplace
+
+################ setup.py #####################
+
+from distutils.core import setup
+from Cython.Build import cythonize
+from Cython.Compiler import Options
+
+Options.cache_builtins = False
+
+setup(
+    ext_modules = cythonize("mview.pyx")
+)
+
+############### mview.pyx ################
+
+# https://github.com/cython/cython/issues/3406
+# Failure was at Cython compilation stage
+
+def f(double [::1] x):
+    pass