Adding cython v0.20.2 in third-party.

third_party/cython/src/Cython/Compiler/Interpreter.py

+"""
+This module deals with interpreting the parse tree as Python
+would have done, in the compiler.
+
+For now this only covers parse tree to value conversion of
+compile-time values.
+"""
+
+from Nodes import *
+from ExprNodes import *
+from Errors import CompileError
+
+
+class EmptyScope(object):
+    def lookup(self, name):
+        return None
+
+empty_scope = EmptyScope()
+
+def interpret_compiletime_options(optlist, optdict, type_env=None, type_args=()):
+    """
+    Tries to interpret a list of compile time option nodes.
+    The result will be a tuple (optlist, optdict) but where
+    all expression nodes have been interpreted. The result is
+    in the form of tuples (value, pos).
+
+    optlist is a list of nodes, while optdict is a DictNode (the
+    result optdict is a dict)
+
+    If type_env is set, all type nodes will be analysed and the resulting
+    type set. Otherwise only interpretateable ExprNodes
+    are allowed, other nodes raises errors.
+
+    A CompileError will be raised if there are problems.
+    """
+
+    def interpret(node, ix):
+        if ix in type_args:
+            if type_env:
+                type = node.analyse_as_type(type_env)
+                if not type:
+                    raise CompileError(node.pos, "Invalid type.")
+                return (type, node.pos)
+            else:
+                raise CompileError(node.pos, "Type not allowed here.")
+        else:
+            if (sys.version_info[0] >=3 and
+                isinstance(node, StringNode) and
+                node.unicode_value is not None):
+                return (node.unicode_value, node.pos)
+            return (node.compile_time_value(empty_scope), node.pos)
+
+    if optlist:
+        optlist = [interpret(x, ix) for ix, x in enumerate(optlist)]
+    if optdict:
+        assert isinstance(optdict, DictNode)
+        new_optdict = {}
+        for item in optdict.key_value_pairs:
+            new_key, dummy = interpret(item.key, None)
+            new_optdict[new_key] = interpret(item.value, item.key.value)
+        optdict = new_optdict
+    return (optlist, new_optdict)