Merge pull request #335 from BigFav/master

Generate warning when Python object is used as C++ container reference parameter.

Cython/Compiler/ExprNodes.py

@@ -2870,7 +2870,8 @@ class IndexNode(ExprNode):
                 type_node = Nodes.TemplatedTypeNode(
                     pos = self.pos,
                     positional_args = template_values,
-                    keyword_args = None)
+                    keyword_args = None,
+                    is_reference = False)
                 return type_node.analyse(env, base_type = base_type)
             else:
                 index = self.index.compile_time_value(env)
@@ -11376,6 +11377,11 @@ class CoerceFromPyTypeNode(CoercionNode):
         if not result_type.create_from_py_utility_code(env):
             error(arg.pos,
                   "Cannot convert Python object to '%s'" % result_type)
+        elif result_type.is_reference:
+            warning(arg.pos,
+                    "Cannot pass Python object as C++ data structure "
+                    "reference (%s &), will pass by copy." % result_type,
+                    level=1)
         if self.type.is_string or self.type.is_pyunicode_ptr:
             if self.arg.is_name and self.arg.entry and self.arg.entry.is_pyglobal:
                 warning(arg.pos,

Cython/Compiler/Nodes.py

@@ -1110,7 +1110,7 @@ class TemplatedTypeNode(CBaseTypeNode):
                         error(template_node.pos, "unknown type in template argument")
                         return error_type
                     template_types.append(type)
-                self.type = base_type.specialize_here(self.pos, template_types)
+                self.type = base_type.specialize_here(self.pos, template_types, is_reference=self.is_reference)
 
         elif base_type.is_pyobject:
             # Buffer
@@ -2821,7 +2821,6 @@ class DefNode(FuncDefNode):
                     error(arg.pos, "Only Python type arguments can have 'not None'")
                 if arg.or_none:
                     error(arg.pos, "Only Python type arguments can have 'or None'")
-
         env.fused_to_specific = f2s
 
     def analyse_signature(self, env):

Cython/Compiler/Parsing.py

@@ -2168,7 +2168,8 @@ def p_buffer_or_template(s, base_type_node, templates):
     result = Nodes.TemplatedTypeNode(pos,
         positional_args = positional_args,
         keyword_args = keyword_dict,
-        base_type_node = base_type_node)
+        base_type_node = base_type_node,
+        is_reference = (s.sy == '&'))
     return result
 
 def p_bracketed_base_type(s, base_type_node, nonempty, empty):

Cython/Compiler/PyrexTypes.py

@@ -4,7 +4,6 @@
 
 from __future__ import absolute_import
 
-import re
 import copy
 import re
 
@@ -3217,7 +3216,7 @@ class CppClassType(CType):
 
     subtypes = ['templates']
 
-    def __init__(self, name, scope, cname, base_classes, templates = None, template_type = None):
+    def __init__(self, name, scope, cname, base_classes, templates = None, template_type = None, is_reference = False):
         self.name = name
         self.cname = cname
         self.scope = scope
@@ -3227,6 +3226,7 @@ class CppClassType(CType):
         self.template_type = template_type
         self.specializations = {}
         self.is_cpp_string = cname in cpp_string_conversions
+        self.is_reference = is_reference
 
     def use_conversion_utility(self, from_or_to):
         pass
@@ -3350,7 +3350,7 @@ class CppClassType(CType):
                 T.get_fused_types(result, seen)
         return result
 
-    def specialize_here(self, pos, template_values = None):
+    def specialize_here(self, pos, template_values = None, is_reference = False):
         if not self.is_template_type():
             error(pos, "'%s' type is not a template" % self)
             return error_type
@@ -3366,19 +3366,19 @@ class CppClassType(CType):
                       "Python object type '%s' cannot be used as a template argument" % value)
         if has_object_template_param:
             return error_type
-        return self.specialize(dict(zip(self.templates, template_values)))
+        return self.specialize(dict(zip(self.templates, template_values)), is_reference)
 
-    def specialize(self, values):
+    def specialize(self, values, is_reference = False):
         if not self.templates and not self.namespace:
             return self
         if self.templates is None:
             self.templates = []
-        key = tuple(values.items())
+        key = tuple(values.items()) + (is_reference,)
         if key in self.specializations:
             return self.specializations[key]
         template_values = [t.specialize(values) for t in self.templates]
         specialized = self.specializations[key] = \
-            CppClassType(self.name, None, self.cname, [], template_values, template_type=self)
+            CppClassType(self.name, None, self.cname, [], template_values, template_type=self, is_reference=is_reference)
         # Need to do these *after* self.specializations[key] is set
         # to avoid infinite recursion on circular references.
         specialized.base_classes = [b.specialize(values) for b in self.base_classes]

tests/errors/w_numpy_arr_as_cppvec_ref.pyx

+# mode: error
+# tag: werror
+
+import numpy as np
+cimport numpy as np
+from libcpp.vector cimport vector
+
+cdef extern from *:
+    void cpp_function_vector1(vector[int])
+    void cpp_function_vector2(vector[int] &)
+    void cpp_function_2_vec_refs(vector[int] &, vector[int] &)
+
+
+def main():
+    cdef np.ndarray[int, ndim=1, mode="c"] arr = np.zeros(10, dtype='intc')
+    cpp_function_vector1(arr)
+    cpp_function_vector2(arr)
+    cpp_function_vector2(arr)
+    cpp_function_2_vec_refs(arr, arr)
+
+    cdef vector[int] vec
+    vec.push_back(0)
+    cpp_function_vector2(vec)
+
+
+_ERRORS = """
+17:28: Cannot pass Python object as C++ data structure reference (vector[int] &), will pass by copy.
+18:28: Cannot pass Python object as C++ data structure reference (vector[int] &), will pass by copy.
+19:31: Cannot pass Python object as C++ data structure reference (vector[int] &), will pass by copy.
+19:36: Cannot pass Python object as C++ data structure reference (vector[int] &), will pass by copy.
+31:15: '<init>' redeclared
+31:15: '<init>' redeclared
+32:15: '<init>' redeclared
+32:15: '<init>' redeclared
+32:15: '<init>' redeclared
+33:15: '<init>' redeclared
+33:15: '<init>' redeclared
+33:15: '<init>' redeclared
+34:15: '<init>' redeclared
+44:19: 'assign' redeclared
+44:19: 'assign' redeclared
+45:35: 'assign' redeclared
+55:22: 'erase' redeclared
+55:22: 'erase' redeclared
+56:22: 'erase' redeclared
+58:23: 'insert' redeclared
+58:23: 'insert' redeclared
+59:19: 'insert' redeclared
+59:19: 'insert' redeclared
+59:19: 'insert' redeclared
+60:19: 'insert' redeclared
+69:19: 'resize' redeclared
+69:19: 'resize' redeclared
+70:19: 'resize' redeclared
+"""

tests/errors/w_python_list_as_cppset_ref.pyx

+# mode: error
+# tag: werror
+
+from libcpp.set cimport set
+
+cdef extern from "foo.cpp":
+    void cpp_function_set1(set[int])
+    void cpp_function_set2(set[int] &)
+
+
+def pass_py_obj_as_cpp_cont_ref():
+    cdef list ordered_set = [0, 0, 0, 0, 0]
+    cpp_function_set1(ordered_set)
+    cpp_function_set2(ordered_set)
+
+
+_ERRORS = """
+5:13: '<init>' redeclared
+5:13: '<init>' redeclared
+6:13: '<init>' redeclared
+6:13: '<init>' redeclared
+6:13: '<init>' redeclared
+6:13: '<init>' redeclared
+6:13: '<init>' redeclared
+7:13: '<init>' redeclared
+7:13: '<init>' redeclared
+7:13: '<init>' redeclared
+14:33: Cannot pass Python object as C++ data structure reference (set[int] &), will pass by copy.
+21:12: '<init>' redeclared
+21:12: '<init>' redeclared
+22:12: '<init>' redeclared
+40:18: 'erase' redeclared
+40:18: 'erase' redeclared
+41:18: 'erase' redeclared
+41:18: 'erase' redeclared
+41:18: 'erase' redeclared
+42:20: 'erase' redeclared
+45:35: 'insert' redeclared
+45:35: 'insert' redeclared
+46:23: 'insert' redeclared
+"""