refactored assignment to memoryviewslice for return values.

Cython/Compiler/ExprNodes.py

@@ -1655,7 +1655,10 @@ class NameNode(AtomicExprNode):
                 rhs.free_temps(code)
         else:
             if self.type.is_memoryviewslice:
-                self.generate_acquire_memoryviewslice(rhs, code)
+                import MemoryView
+                MemoryView.gen_acquire_memoryviewslice(rhs, self.type,
+                        self.entry.is_cglobal, self.result(), self.pos, code)
+                # self.generate_acquire_memoryviewslice(rhs, code)
 
             elif self.type.is_buffer:
                 # Generate code for doing the buffer release/acquisition.
@@ -1699,30 +1702,6 @@ class NameNode(AtomicExprNode):
                 rhs.generate_post_assignment_code(code)
             rhs.free_temps(code)
 
-    def generate_acquire_memoryviewslice(self, rhs, code):
-        # to explicitly manange the memviewslice.memview object correctly.
-        import MemoryView
-        assert rhs.type.is_memoryviewslice
-        if not rhs.result_in_temp():
-            code.put_incref("%s.memview" % rhs.result(), cython_memoryview_ptr_type)
-
-        if self.entry.is_cglobal:
-            code.put_gotref("%s.memview" % self.result())
-
-        if not self.lhs_of_first_assignment:
-            if self.entry.is_local and not Options.init_local_none:
-                code.put_xdecref("%s.memview" % self.result(), cython_memoryview_ptr_type)
-            else:
-                code.put_decref("%s.memview" % self.result(), cython_memoryview_ptr_type)
-
-        if self.entry.is_cglobal:
-            code.put_giveref("%s.memview" % rhs.result())
-
-        MemoryView.put_assign_to_memviewslice(self.result(), rhs.result(), self.type,
-                                         pos=self.pos, code=code)
-        if rhs.result_in_temp():
-            code.putln("%s.memview = 0;" % rhs.result())
-
     def generate_acquire_buffer(self, rhs, code):
         # rhstmp is only used in case the rhs is a complicated expression leading to
         # the object, to avoid repeating the same C expression for every reference
@@ -7623,7 +7602,7 @@ class CoerceToMemViewSliceNode(CoercionNode):
         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))
+                        (memviewobj, self.arg.py_result(), buf_flag))
         ndim = len(self.type.axes)
         spec_int_arr = code.funcstate.allocate_temp(
                 PyrexTypes.c_array_type(PyrexTypes.c_int_type, ndim),

Cython/Compiler/MemoryView.py

@@ -67,8 +67,41 @@ def format_from_type(base_type):
 
 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_ptr_type)
-    code.put_giveref(code.as_pyobject("%s.memview" % mv_cname, cython_memoryview_ptr_type))
+    code.putln("%s.memview = NULL;" % mv_cname)
+
+def gen_acquire_memoryviewslice(rhs, lhs_type, lhs_is_cglobal, lhs_result, lhs_pos, code):
+    # import MemoryView
+    assert rhs.type.is_memoryviewslice
+
+    pretty_rhs = isinstance(rhs, NameNode) or rhs.result_in_temp()
+    if pretty_rhs:
+        rhstmp = rhs.result()
+    else:
+        rhstmp = code.funcstate.allocate_temp(lhs_type, manage_ref=False)
+        code.putln("%s = %s;" % (rhstmp, rhs.result_as(lhs_type)))
+
+    if not rhs.result_in_temp():
+        code.put_incref("%s.memview" % rhstmp, cython_memoryview_ptr_type)
+
+    if lhs_is_cglobal:
+        code.put_gotref("%s.memview" % lhs_result)
+
+    #XXX: this is here because self.lhs_of_first_assignment is not set correctly,
+    #     once that is working this should take that flag into account.
+    #     See NameNode.generate_assignment_code
+    code.put_xdecref("%s.memview" % lhs_result, cython_memoryview_ptr_type)
+
+    if lhs_is_cglobal:
+        code.put_giveref("%s.memview" % rhstmp)
+
+    put_assign_to_memviewslice(lhs_result, rhstmp, lhs_type,
+                                     lhs_pos, code=code)
+
+    if rhs.result_in_temp() or not pretty_rhs:
+        code.putln("%s.memview = 0;" % rhstmp)
+
+    if not pretty_rhs:
+        code.funcstate.release_temp(rhstmp)
 
 def put_assign_to_memviewslice(lhs_cname, rhs_cname, memviewslicetype, pos, code):
 

Cython/Compiler/Nodes.py

@@ -1349,6 +1349,9 @@ class FuncDefNode(StatNode, BlockNode):
                 "%s%s;" %
                     (self.return_type.declaration_code(Naming.retval_cname),
                      init))
+            if self.return_type.is_memoryviewslice:
+                import MemoryView
+                MemoryView.put_init_entry(Naming.retval_cname, code)
         tempvardecl_code = code.insertion_point()
         self.generate_keyword_list(code)
 
@@ -1561,6 +1564,8 @@ class FuncDefNode(StatNode, BlockNode):
                 err_val = default_retval
             if self.return_type.is_pyobject:
                 code.put_xgiveref(self.return_type.as_pyobject(Naming.retval_cname))
+            elif self.return_type.is_memoryviewslice:
+                code.put_xgiveref(code.as_pyobject("%s.memview" % Naming.retval_cname,cython_memoryview_ptr_type))
 
         if self.entry.is_special and self.entry.name == "__hash__":
             # Returning -1 for __hash__ is supposed to signal an error
@@ -4265,10 +4270,22 @@ class ReturnStatNode(StatNode):
         if self.return_type.is_pyobject:
             code.put_xdecref(Naming.retval_cname,
                              self.return_type)
+        elif self.return_type.is_memoryviewslice:
+            code.put_xdecref("%s.memview" % Naming.retval_cname,
+                    self.return_type)
+
         if self.value:
             self.value.generate_evaluation_code(code)
+            if self.return_type.is_memoryviewslice:
+                import MemoryView
+                MemoryView.gen_acquire_memoryviewslice(self.value, self.return_type,
+                        False, Naming.retval_cname, None, code)
+            else:
                 self.value.make_owned_reference(code)
-            self.put_return(code, self.value.result_as(self.return_type))
+                code.putln(
+                    "%s = %s;" % (
+                        Naming.retval_cname,
+                        self.value.result_as(self.return_type)))
                 self.value.generate_post_assignment_code(code)
             self.value.free_temps(code)
         else:

Cython/Compiler/PyrexTypes.py

@@ -317,6 +317,9 @@ class MemoryViewSliceType(PyrexType):
 
     is_memoryviewslice = 1
 
+    has_attributes = 1
+    scope = None
+
     def __init__(self, base_dtype, axes, env):
         '''
         MemoryViewSliceType(base, axes)
@@ -372,6 +375,15 @@ class MemoryViewSliceType(PyrexType):
                 MemoryView.memviewslice_cname,
                 entity_code)
 
+    def attributes_known(self):
+        if self.scope is None:
+            import Symtab
+            self.scope = Symtab.StructOrUnionScope(self.specalization_name())
+            # XXX: we don't necessarily want to have this exposed -- for
+            # testing purposes currently.
+            self.scope.declare_var("data", c_char_ptr_type, None, "data")
+        return True
+
     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_ptr_type, nanny=False)

tests/run/memoryview.pyx

@@ -2,6 +2,7 @@ u'''
 >>> f()
 >>> g()
 >>> call()
+>>> assignmvs()
 '''
 
 from cython.view cimport memoryview
@@ -9,10 +10,22 @@ from cython cimport array, PyBUF_C_CONTIGUOUS
 
 def init_obj():
     return 3
+
 cdef passmvs(float[:,::1] mvs, object foo):
     mvs = array((10,10), itemsize=sizeof(float), format='f')
     foo = init_obj()
 
+cdef object returnobj():
+    cdef obj = object()
+    return obj
+
+cdef float[::1] returnmvs_inner():
+    return array((10,), itemsize=sizeof(float), format='f')
+
+cdef float[::1] returnmvs():
+    cdef float[::1] mvs = returnmvs_inner()
+    return mvs
+
 def f():
     cdef array arr = array(shape=(10,10), itemsize=sizeof(int), format='i')
     cdef memoryview mv = memoryview(arr, PyBUF_C_CONTIGUOUS)
@@ -43,10 +56,20 @@ cdef float[:,::1] global_mv = array((10,10), itemsize=sizeof(float), format='f')
 global_mv = array((10,10), itemsize=sizeof(float), format='f')
 cdef object global_obj
 
+def assignmvs():
+    cdef int[::1] mv1, mv2
+    mv1 = array((10,), itemsize=sizeof(int), format='i')
+    mv2 = mv1
+    mv1 = mv2
+
 def call():
     global global_mv
     passmvs(global_mv, global_obj)
     global_mv = array((3,3), itemsize=sizeof(float), format='f')
+    cdef float[::1] getmvs = returnmvs()
+    returnmvs()
+    cdef object obj = returnobj()
     cdg()
     f = Foo()
     pf = pyfoo()
+