Argument parsing error handling

Cython/Compiler/ExprNodes.py

@@ -3588,20 +3588,7 @@ class CoerceFromPyTypeNode(CoercionNode):
         code.putln('%s = %s; %s' % (
             self.result_code, 
             rhs,
-            code.error_goto_if(self.error_cond(), self.pos)))
-
-    def error_cond(self):
-        conds = []
-        if self.type.is_string:
-            conds.append("(!%s)" % self.result_code)
-        elif self.type.exception_value is not None:
-            conds.append("(%s == %s)" % (self.result_code, self.type.exception_value))
-        if self.type.exception_check:
-            conds.append("PyErr_Occurred()")
-        if len(conds) > 0:
-            return " && ".join(conds)
-        else:
-            return 0
+            code.error_goto_if(self.type.error_condition(self.result_code), self.pos)))
 
 
 class CoerceToBooleanNode(CoercionNode):

Cython/Compiler/Nodes.py

@@ -1311,12 +1311,13 @@ class DefNode(FuncDefNode):
     def generate_arg_conversion_from_pyobject(self, arg, code):
         new_type = arg.type
         func = new_type.from_py_function
+        # copied from CoerceFromPyTypeNode
         if func:
             code.putln("%s = %s(%s); %s" % (
                 arg.entry.cname,
                 func,
                 arg.hdr_cname,
-                code.error_goto_if_PyErr(arg.pos)))
+                code.error_goto_if(new_type.error_condition(arg.entry.cname), arg.pos)))
         else:
             error(arg.pos, 
                 "Cannot convert Python object argument to type '%s'" 

Cython/Compiler/PyrexTypes.py

@@ -302,6 +302,19 @@ class CType(PyrexType):
     from_py_function = None
     exception_value = None
     exception_check = 1
+    
+    def error_condition(self, result_code):
+        conds = []
+        if self.is_string:
+            conds.append("(!%s)" % result_code)
+        elif self.exception_value is not None:
+            conds.append("(%s == (%s)%s)" % (result_code, self.sign_and_name(), self.exception_value))
+        if self.exception_check:
+            conds.append("PyErr_Occurred()")
+        if len(conds) > 0:
+            return " && ".join(conds)
+        else:
+            return 0
 
 
 class CVoidType(CType):
@@ -432,7 +445,7 @@ class CUIntType(CIntType):
 
     to_py_function = "PyLong_FromUnsignedLong"
     from_py_function = "PyInt_AsUnsignedLongMask"
-    exception_value = None
+    exception_value = -1
 
 
 class CULongType(CUIntType):