memoryviewslice declaration and assignments work.

Cython/Compiler/CythonScope.py

@@ -257,6 +257,11 @@ cdef full = Enum("<full axis access mode>")
 cdef extern from *:
     int __Pyx_GetBuffer(object, Py_buffer *, int)
     void __Pyx_ReleaseBuffer(Py_buffer *)
+    void __Pyx_XDECREF(object)
+    void __Pyx_DECREF(object)
+    void __Pyx_GIVEREF(object)
+    void __Pyx_INCREF(object)
+    void __Pyx_GOTREF(object)
 
 
 cdef class memoryview(object):
@@ -389,9 +394,13 @@ cdef object init_memviewslice_from_memview(
         if has_suboffsets:
             memviewslice.diminfo[i].suboffsets = pybuf.suboffsets[i]
 
+    __Pyx_INCREF(<object>memview)
+    __Pyx_GIVEREF(<object>memview)
+    __Pyx_GOTREF(<object>memviewslice.memview)
+    __Pyx_DECREF(<object>memviewslice.memview)
     memviewslice.memview = <__pyx_obj_memoryview*>memview
-    memviewslice.data = <char *>pybuf.buf
 
+    memviewslice.data = <char *>pybuf.buf
 """ % Options.buffer_max_dims, name="foobar", prefix="__pyx_viewaxis_")
 
 cyarray_prefix = u'__pyx_cythonarray_'

Cython/Compiler/ExprNodes.py

@@ -585,11 +585,15 @@ class ExprNode(Node):
             dst_type = dst_type.ref_base_type
 
         if dst_type.is_memoryview:
+            import MemoryView
+            if not src.type.is_memoryview:
                 src = CoerceToMemViewNode(src, dst_type, env)
-            # src = AcquireBufferFromNode(src, env)
-            # src = CheckMemoryViewFormatNode(src, dst_type, env)
+            elif not MemoryView.src_conforms_to_dst(src.type, dst_type):
+                error(self.pos, "Memoryview '%s' not conformable to memoryview '%s'." %
+                        (src.type, dst_type))
 
-        if dst_type.is_pyobject:
+
+        elif dst_type.is_pyobject:
             if not src.type.is_pyobject:
                 if dst_type is bytes_type and src.type.is_int:
                     src = CoerceIntToBytesNode(src, env)
@@ -1653,7 +1657,7 @@ class NameNode(AtomicExprNode):
             if self.type.is_memoryview:
                 self.generate_acquire_memoryview(rhs, code)
 
-            if self.type.is_buffer:
+            elif self.type.is_buffer:
                 # Generate code for doing the buffer release/acquisition.
                 # This might raise an exception in which case the assignment (done
                 # below) will not happen.
@@ -1687,9 +1691,8 @@ class NameNode(AtomicExprNode):
                                 code.put_decref(self.result(), self.ctype())
                     if is_external_ref:
                         code.put_giveref(rhs.py_result())
-
-            code.putln('%s = %s;' % (self.result(),
-                                     rhs.result_as(self.ctype())))
+            if not self.type.is_memoryview:
+                code.putln('%s = %s;' % (self.result(), rhs.result_as(self.ctype())))
             if debug_disposal_code:
                 print("NameNode.generate_assignment_code:")
                 print("...generating post-assignment code for %s" % rhs)
@@ -1698,9 +1701,10 @@ class NameNode(AtomicExprNode):
 
     def generate_acquire_memoryview(self, rhs, code):
         import MemoryView
-        MemoryView.put_assign_to_memview(self.result(), rhs.result(), self.entry,
-                                         is_initialized=not self.lhs_of_first_assignment,
+        MemoryView.put_assign_to_memview(self.result(), rhs.result(), self.type,
                                          pos=self.pos, code=code)
+        if rhs.is_temp:
+            code.put_xdecref_clear("%s.memview" % rhs.result(), py_object_type)
 
     def generate_acquire_buffer(self, rhs, code):
         # rhstmp is only used in case the rhs is a complicated expression leading to
@@ -3940,6 +3944,13 @@ class AttributeNode(ExprNode):
                 code.put_giveref(rhs.py_result())
                 code.put_gotref(select_code)
                 code.put_decref(select_code, self.ctype())
+            elif self.type.is_memoryview:
+                import MemoryView
+                MemoryView.put_assign_to_memview(select_code, rhs.result(), self.type,
+                        pos=self.pos, code=code)
+                if rhs.is_temp:
+                    code.put_xdecref_clear("%s.memview" % rhs.result(), py_object_type)
+            if not self.type.is_memoryview:
                 code.putln(
                     "%s = %s;" % (
                         select_code,
@@ -7583,27 +7594,35 @@ class CoerceToMemViewNode(CoercionNode):
 
     def __init__(self, arg, dst_type, env):
         assert dst_type.is_memoryview
+        assert not arg.type.is_memoryview
         CoercionNode.__init__(self, arg)
         self.type = dst_type
-        self.is_temp = 1
         self.env = env
+        self.is_temp = 1
 
     def generate_result_code(self, code):
         import MemoryView
         memviewobj = code.funcstate.allocate_temp(PyrexTypes.py_object_type, manage_ref=True)
         buf_flag = MemoryView.get_buf_flag(self.type.axes)
-        code.putln("%s = (PyObject *)__pyx_viewaxis_memoryview_cwrapper(%s, %s);" % (memviewobj, self.arg.result(), buf_flag))
+        code.putln("%s = (PyObject *)"
+                "__pyx_viewaxis_memoryview_cwrapper(%s, %s);" %\
+                        (memviewobj, self.arg.result(), buf_flag))
         ndim = len(self.type.axes)
-        spec_int_arr = code.funcstate.allocate_temp(PyrexTypes.c_array_type(PyrexTypes.c_int_type, ndim),manage_ref=True)
+        spec_int_arr = code.funcstate.allocate_temp(
+                PyrexTypes.c_array_type(PyrexTypes.c_int_type, ndim),
+                manage_ref=False)
         specs_code = MemoryView.specs_to_code(self.type.axes)
         for idx, cspec in enumerate(specs_code):
             code.putln("%s[%d] = %s;" % (spec_int_arr, idx, cspec))
         itemsize = self.type.dtype.sign_and_name()
         format = MemoryView.format_from_type(self.type.dtype)
-        code.putln("__pyx_viewaxis_init_memviewslice_from_memview((struct __pyx_obj_memoryview *)%s, %s, %d, sizeof(%s), \"%s\", &%s);" % (memviewobj, spec_int_arr, ndim, itemsize, format, self.result()))
+        MemoryView.put_init_entry(self.result(), code)
+        code.putln("__pyx_viewaxis_init_memviewslice_from_memview"
+                "((struct __pyx_obj_memoryview *)%s, %s, %d, sizeof(%s), \"%s\", &%s);" %\
+                (memviewobj, spec_int_arr, ndim, itemsize, format, self.result()))
+        code.put_gotref("%s.memview" % self.result())
         code.funcstate.release_temp(memviewobj)
         code.funcstate.release_temp(spec_int_arr)
-        code.putln('/* @@@ */')
 
 class CastNode(CoercionNode):
     #  Wrap a node in a C type cast.

Cython/Compiler/MemoryView.py

@@ -5,6 +5,7 @@ import Options
 import CythonScope
 from Code import UtilityCode
 from UtilityCode import CythonUtilityCode
+from PyrexTypes import py_object_type, cython_memoryview_type
 
 START_ERR = "there must be nothing or the value 0 (zero) in the start slot."
 STOP_ERR = "Axis specification only allowed in the 'stop' slot."
@@ -64,9 +65,24 @@ _typename_to_format = {
 def format_from_type(base_type):
     return _typename_to_format[base_type.sign_and_name()]
 
-def put_assign_to_memview(lhs_cname, rhs_cname, buf_entry,
-                         is_initialized, pos, code):
-    pass
+def put_init_entry(mv_cname, code):
+    code.putln("%s.data = NULL;" % mv_cname)
+    code.put_init_to_py_none("%s.memview" % mv_cname, cython_memoryview_type)
+    code.put_giveref("%s.memview" % mv_cname)
+
+def put_assign_to_memview(lhs_cname, rhs_cname, memviewtype, pos, code):
+
+    # XXX: add error checks!
+
+    code.put_giveref("%s.memview" % (rhs_cname))
+    code.put_incref("%s.memview" % (rhs_cname), py_object_type)
+    code.put_gotref("%s.memview" % (lhs_cname))
+    code.put_xdecref("%s.memview" % (lhs_cname), py_object_type)
+    code.putln("%s.memview = %s.memview;" % (lhs_cname, rhs_cname))
+    code.putln("%s.data = %s.data;" % (lhs_cname, rhs_cname))
+    ndim = len(memviewtype.axes)
+    for i in range(ndim):
+        code.putln("%s.diminfo[%d] = %s.diminfo[%d];" % (lhs_cname, i, rhs_cname, i))
 
 def get_buf_flag(specs):
     is_c_contig, is_f_contig = is_cf_contig(specs)
@@ -101,6 +117,36 @@ def use_memview_cwrap(env):
     import CythonScope
     mv_cwrap_entry = use_cython_util_code(env, CythonScope.memview_cwrap_name)
 
+def src_conforms_to_dst(src, dst):
+    '''
+    returns True if src conforms to dst, False otherwise.
+
+    If conformable, the types are the same, the ndims are equal, and each axis spec is conformable.
+
+    Any packing/access spec is conformable to itself.
+
+    'contig' and 'follow' are conformable to 'strided'.
+
+    'direct' and 'ptr' are conformable to 'full'.
+
+    Any other combo is not conformable.
+    '''
+
+    if src.dtype != dst.dtype:
+        return False
+    if len(src.axes) != len(dst.axes):
+        return False
+
+    for src_spec, dst_spec in zip(src.axes, dst.axes):
+        src_access, src_packing = src_spec
+        dst_access, dst_packing = dst_spec
+        if src_access != dst_access and dst_access != 'strided':
+            return False
+        if src_packing != dst_packing and dst_packing != 'full':
+            return False
+
+    return True
+
 
 def get_axes_specs(env, axes):
     '''

Cython/Compiler/ModuleNode.py

@@ -1185,10 +1185,13 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         type = scope.parent_type
         base_type = type.base_type
         py_attrs = []
+        memview_attrs = []
         for entry in scope.var_entries:
             if entry.type.is_pyobject:
                 py_attrs.append(entry)
-        need_self_cast = type.vtabslot_cname or py_attrs
+            elif entry.type.is_memoryview:
+                memview_attrs.append(entry)
+        need_self_cast = type.vtabslot_cname or py_attrs or memview_attrs
         code.putln("")
         code.putln(
             "static PyObject *%s(PyTypeObject *t, PyObject *a, PyObject *k) {"
@@ -1231,6 +1234,10 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
                 code.putln("p->%s = 0;" % entry.cname)
             else:
                 code.put_init_var_to_py_none(entry, "p->%s", nanny=False)
+        for entry in memview_attrs:
+            code.putln("p->%s.data = NULL;" % entry.cname)
+            code.put_init_to_py_none("p->%s.memview" % entry.cname,
+                    PyrexTypes.cython_memoryview_type, nanny=False)
         entry = scope.lookup_here("__new__")
         if entry and entry.is_special:
             if entry.trivial_signature:
@@ -2134,8 +2141,8 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         # variables to None.
         for entry in env.var_entries:
             if entry.visibility != 'extern':
-                if entry.type.is_pyobject and entry.used:
-                    code.put_init_var_to_py_none(entry, nanny=False)
+                if entry.used:
+                    entry.type.global_init_code(entry, code)
 
     def generate_c_variable_export_code(self, env, code):
         # Generate code to create PyCFunction wrappers for exported C functions.

Cython/Compiler/Nodes.py

@@ -1261,7 +1261,7 @@ class FuncDefNode(StatNode, BlockNode):
         self.body.generate_execution_code(code)
 
     def generate_function_definitions(self, env, code):
-        import Buffer
+        import Buffer, MemoryView
 
         lenv = self.local_scope
         if lenv.is_closure_scope and not lenv.is_passthrough:
@@ -1428,6 +1428,10 @@ class FuncDefNode(StatNode, BlockNode):
         for entry in lenv.var_entries + lenv.arg_entries:
             if entry.type.is_buffer and entry.buffer_aux.buflocal_nd_var.used:
                 Buffer.put_init_vars(entry, code)
+        # ----- Initialise local memoryviews
+        for entry in lenv.var_entries + lenv.arg_entries:
+            if entry.type.is_memoryview:
+                MemoryView.put_init_entry(entry.cname, code)
         # ----- Check and convert arguments
         self.generate_argument_type_tests(code)
         # ----- Acquire buffer arguments

Cython/Compiler/PyrexTypes.py

@@ -170,6 +170,10 @@ class PyrexType(BaseType):
         # type information of the struct.
         return 1
 
+    def global_init_code(self, entry, code):
+        # abstract
+        raise NotImplementedError()
+
 
 def public_decl(base_code, dll_linkage):
     if dll_linkage:
@@ -362,11 +366,16 @@ class MemoryViewType(PyrexType):
         assert not pyrex
         assert not dll_linkage
         import MemoryView
+        if not for_display:
             self.env.use_utility_code(MemoryView.memviewslice_declare_code)
         return self.base_declaration_code(
                 MemoryView.memviewslice_cname,
                 entity_code)
 
+    def global_init_code(self, entry, code):
+        code.putln("%s.data = NULL;" % entry.cname)
+        code.put_init_to_py_none("%s.memview" % entry.cname, cython_memoryview_type, nanny=False)
+
 class BufferType(BaseType):
     #
     #  Delegates most attribute
@@ -447,6 +456,12 @@ class PyObjectType(PyrexType):
         else:
             return cname
 
+    def invalid_value(self):
+        return "1"
+
+    def global_init_code(self, entry, code):
+        code.put_init_var_to_py_none(entry, nanny=False)
+
 
 class BuiltinObjectType(PyObjectType):
     #  objstruct_cname  string           Name of PyObject struct
@@ -2547,8 +2562,8 @@ c_pyx_buffer_ptr_type = CPtrType(c_pyx_buffer_type)
 c_pyx_buffer_nd_type = CStructOrUnionType("__Pyx_LocalBuf_ND", "struct",
                                       None, 1, "__Pyx_LocalBuf_ND")
 
-cython_memoryview_type = CStructOrUnionType("__pyx_obj_memoryview", "struct",
-                                      None, 1, "__pyx_obj_memoryview")
+cython_memoryview_type = CPtrType(CStructOrUnionType("__pyx_obj_memoryview", "struct",
+                                      None, 0, "__pyx_obj_memoryview"))
 
 
 error_type =    ErrorType()

tests/run/memoryview.pyx

@@ -12,7 +12,6 @@ def f():
     cdef memoryview mv = memoryview(arr, PyBUF_C_CONTIGUOUS)
 
 def g():
-    # cdef int[::1] mview = array((10,), itemsize=sizeof(int), format='i')
     cdef int[::1] mview = array((10,), itemsize=sizeof(int), format='i')
     mview = array((10,), itemsize=sizeof(int), format='i')
 
@@ -36,6 +35,8 @@ cdef float[:,::1] global_mv = array((10,10), itemsize=sizeof(float), format='f')
 global_mv = array((10,10), itemsize=sizeof(float), format='f')
 
 def call():
+    global global_mv
+    global_mv = array((3,3), itemsize=sizeof(float), format='f')
     cdg()
     f = Foo()
     pf = pyfoo()