Adding cython v0.20.2 in third-party.

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

+#
+# Nodes used as utilities and support for transforms etc.
+# These often make up sets including both Nodes and ExprNodes
+# so it is convenient to have them in a seperate module.
+#
+
+import Nodes
+import ExprNodes
+from Nodes import Node
+from ExprNodes import AtomicExprNode
+from PyrexTypes import c_ptr_type
+
+class TempHandle(object):
+    # THIS IS DEPRECATED, USE LetRefNode instead
+    temp = None
+    needs_xdecref = False
+    def __init__(self, type, needs_cleanup=None):
+        self.type = type
+        if needs_cleanup is None:
+            self.needs_cleanup = type.is_pyobject
+        else:
+            self.needs_cleanup = needs_cleanup
+
+    def ref(self, pos):
+        return TempRefNode(pos, handle=self, type=self.type)
+
+    def cleanup_ref(self, pos):
+        return CleanupTempRefNode(pos, handle=self, type=self.type)
+
+class TempRefNode(AtomicExprNode):
+    # THIS IS DEPRECATED, USE LetRefNode instead
+    # handle   TempHandle
+
+    def analyse_types(self, env):
+        assert self.type == self.handle.type
+        return self
+
+    def analyse_target_types(self, env):
+        assert self.type == self.handle.type
+        return self
+
+    def analyse_target_declaration(self, env):
+        pass
+
+    def calculate_result_code(self):
+        result = self.handle.temp
+        if result is None: result = "<error>" # might be called and overwritten
+        return result
+
+    def generate_result_code(self, code):
+        pass
+
+    def generate_assignment_code(self, rhs, code):
+        if self.type.is_pyobject:
+            rhs.make_owned_reference(code)
+            # TODO: analyse control flow to see if this is necessary
+            code.put_xdecref(self.result(), self.ctype())
+        code.putln('%s = %s;' % (self.result(), rhs.result_as(self.ctype())))
+        rhs.generate_post_assignment_code(code)
+        rhs.free_temps(code)
+
+class CleanupTempRefNode(TempRefNode):
+    # THIS IS DEPRECATED, USE LetRefNode instead
+    # handle   TempHandle
+
+    def generate_assignment_code(self, rhs, code):
+        pass
+
+    def generate_execution_code(self, code):
+        if self.type.is_pyobject:
+            code.put_decref_clear(self.result(), self.type)
+            self.handle.needs_cleanup = False
+
+class TempsBlockNode(Node):
+    # THIS IS DEPRECATED, USE LetNode instead
+
+    """
+    Creates a block which allocates temporary variables.
+    This is used by transforms to output constructs that need
+    to make use of a temporary variable. Simply pass the types
+    of the needed temporaries to the constructor.
+
+    The variables can be referred to using a TempRefNode
+    (which can be constructed by calling get_ref_node).
+    """
+
+    # temps   [TempHandle]
+    # body    StatNode
+
+    child_attrs = ["body"]
+
+    def generate_execution_code(self, code):
+        for handle in self.temps:
+            handle.temp = code.funcstate.allocate_temp(
+                handle.type, manage_ref=handle.needs_cleanup)
+        self.body.generate_execution_code(code)
+        for handle in self.temps:
+            if handle.needs_cleanup:
+                if handle.needs_xdecref:
+                    code.put_xdecref_clear(handle.temp, handle.type)
+                else:
+                    code.put_decref_clear(handle.temp, handle.type)
+            code.funcstate.release_temp(handle.temp)
+
+    def analyse_declarations(self, env):
+        self.body.analyse_declarations(env)
+
+    def analyse_expressions(self, env):
+        self.body = self.body.analyse_expressions(env)
+        return self
+
+    def generate_function_definitions(self, env, code):
+        self.body.generate_function_definitions(env, code)
+
+    def annotate(self, code):
+        self.body.annotate(code)
+
+
+class ResultRefNode(AtomicExprNode):
+    # A reference to the result of an expression.  The result_code
+    # must be set externally (usually a temp name).
+
+    subexprs = []
+    lhs_of_first_assignment = False
+
+    def __init__(self, expression=None, pos=None, type=None, may_hold_none=True, is_temp=False):
+        self.expression = expression
+        self.pos = None
+        self.may_hold_none = may_hold_none
+        if expression is not None:
+            self.pos = expression.pos
+            if hasattr(expression, "type"):
+                self.type = expression.type
+        if pos is not None:
+            self.pos = pos
+        if type is not None:
+            self.type = type
+        if is_temp:
+            self.is_temp = True
+        assert self.pos is not None
+
+    def clone_node(self):
+        # nothing to do here
+        return self
+
+    def type_dependencies(self, env):
+        if self.expression:
+            return self.expression.type_dependencies(env)
+        else:
+            return ()
+
+    def analyse_types(self, env):
+        if self.expression is not None:
+            self.type = self.expression.type
+        return self
+
+    def infer_type(self, env):
+        if self.type is not None:
+            return self.type
+        if self.expression is not None:
+            if self.expression.type is not None:
+                return self.expression.type
+            return self.expression.infer_type(env)
+        assert False, "cannot infer type of ResultRefNode"
+
+    def may_be_none(self):
+        if not self.type.is_pyobject:
+            return False
+        return self.may_hold_none
+
+    def _DISABLED_may_be_none(self):
+        # not sure if this is safe - the expression may not be the
+        # only value that gets assigned
+        if self.expression is not None:
+            return self.expression.may_be_none()
+        if self.type is not None:
+            return self.type.is_pyobject
+        return True # play safe
+
+    def is_simple(self):
+        return True
+
+    def result(self):
+        try:
+            return self.result_code
+        except AttributeError:
+            if self.expression is not None:
+                self.result_code = self.expression.result()
+        return self.result_code
+
+    def generate_evaluation_code(self, code):
+        pass
+
+    def generate_result_code(self, code):
+        pass
+
+    def generate_disposal_code(self, code):
+        pass
+
+    def generate_assignment_code(self, rhs, code):
+        if self.type.is_pyobject:
+            rhs.make_owned_reference(code)
+            if not self.lhs_of_first_assignment:
+                code.put_decref(self.result(), self.ctype())
+        code.putln('%s = %s;' % (self.result(), rhs.result_as(self.ctype())))
+        rhs.generate_post_assignment_code(code)
+        rhs.free_temps(code)
+
+    def allocate_temps(self, env):
+        pass
+
+    def release_temp(self, env):
+        pass
+
+    def free_temps(self, code):
+        pass
+
+
+class LetNodeMixin:
+    def set_temp_expr(self, lazy_temp):
+        self.lazy_temp = lazy_temp
+        self.temp_expression = lazy_temp.expression
+
+    def setup_temp_expr(self, code):
+        self.temp_expression.generate_evaluation_code(code)
+        self.temp_type = self.temp_expression.type
+        if self.temp_type.is_array:
+            self.temp_type = c_ptr_type(self.temp_type.base_type)
+        self._result_in_temp = self.temp_expression.result_in_temp()
+        if self._result_in_temp:
+            self.temp = self.temp_expression.result()
+        else:
+            self.temp_expression.make_owned_reference(code)
+            self.temp = code.funcstate.allocate_temp(
+                self.temp_type, manage_ref=True)
+            code.putln("%s = %s;" % (self.temp, self.temp_expression.result()))
+            self.temp_expression.generate_disposal_code(code)
+            self.temp_expression.free_temps(code)
+        self.lazy_temp.result_code = self.temp
+
+    def teardown_temp_expr(self, code):
+        if self._result_in_temp:
+            self.temp_expression.generate_disposal_code(code)
+            self.temp_expression.free_temps(code)
+        else:
+            if self.temp_type.is_pyobject:
+                code.put_decref_clear(self.temp, self.temp_type)
+            code.funcstate.release_temp(self.temp)
+
+class EvalWithTempExprNode(ExprNodes.ExprNode, LetNodeMixin):
+    # A wrapper around a subexpression that moves an expression into a
+    # temp variable and provides it to the subexpression.
+
+    subexprs = ['temp_expression', 'subexpression']
+
+    def __init__(self, lazy_temp, subexpression):
+        self.set_temp_expr(lazy_temp)
+        self.pos = subexpression.pos
+        self.subexpression = subexpression
+        # if called after type analysis, we already know the type here
+        self.type = self.subexpression.type
+
+    def infer_type(self, env):
+        return self.subexpression.infer_type(env)
+
+    def result(self):
+        return self.subexpression.result()
+
+    def analyse_types(self, env):
+        self.temp_expression = self.temp_expression.analyse_types(env)
+        self.subexpression = self.subexpression.analyse_types(env)
+        self.type = self.subexpression.type
+        return self
+
+    def free_subexpr_temps(self, code):
+        self.subexpression.free_temps(code)
+
+    def generate_subexpr_disposal_code(self, code):
+        self.subexpression.generate_disposal_code(code)
+
+    def generate_evaluation_code(self, code):
+        self.setup_temp_expr(code)
+        self.subexpression.generate_evaluation_code(code)
+        self.teardown_temp_expr(code)
+
+LetRefNode = ResultRefNode
+
+class LetNode(Nodes.StatNode, LetNodeMixin):
+    # Implements a local temporary variable scope. Imagine this
+    # syntax being present:
+    # let temp = VALUE:
+    #     BLOCK (can modify temp)
+    #     if temp is an object, decref
+    #
+    # Usually used after analysis phase, but forwards analysis methods
+    # to its children
+
+    child_attrs = ['temp_expression', 'body']
+
+    def __init__(self, lazy_temp, body):
+        self.set_temp_expr(lazy_temp)
+        self.pos = body.pos
+        self.body = body
+
+    def analyse_declarations(self, env):
+        self.temp_expression.analyse_declarations(env)
+        self.body.analyse_declarations(env)
+
+    def analyse_expressions(self, env):
+        self.temp_expression = self.temp_expression.analyse_expressions(env)
+        self.body = self.body.analyse_expressions(env)
+        return self
+
+    def generate_execution_code(self, code):
+        self.setup_temp_expr(code)
+        self.body.generate_execution_code(code)
+        self.teardown_temp_expr(code)
+
+    def generate_function_definitions(self, env, code):
+        self.temp_expression.generate_function_definitions(env, code)
+        self.body.generate_function_definitions(env, code)
+
+
+class TempResultFromStatNode(ExprNodes.ExprNode):
+    # An ExprNode wrapper around a StatNode that executes the StatNode
+    # body.  Requires a ResultRefNode that it sets up to refer to its
+    # own temp result.  The StatNode must assign a value to the result
+    # node, which then becomes the result of this node.
+
+    subexprs = []
+    child_attrs = ['body']
+
+    def __init__(self, result_ref, body):
+        self.result_ref = result_ref
+        self.pos = body.pos
+        self.body = body
+        self.type = result_ref.type
+        self.is_temp = 1
+
+    def analyse_declarations(self, env):
+        self.body.analyse_declarations(env)
+
+    def analyse_types(self, env):
+        self.body = self.body.analyse_expressions(env)
+        return self
+
+    def generate_result_code(self, code):
+        self.result_ref.result_code = self.result()
+        self.body.generate_execution_code(code)