Fix lambda's default args, ticket #723

Cython/Compiler/ExprNodes.py

@@ -5258,10 +5258,20 @@ class LambdaNode(InnerFunctionNode):
     name = StringEncoding.EncodedString('<lambda>')
 
     def analyse_declarations(self, env):
+        self.def_node.no_assignment_synthesis = True
+        self.def_node.pymethdef_required = True
         self.def_node.analyse_declarations(env)
         self.pymethdef_cname = self.def_node.entry.pymethdef_cname
         env.add_lambda_def(self.def_node)
 
+    def analyse_types(self, env):
+        self.def_node.analyse_expressions(env)
+        super(LambdaNode, self).analyse_types(env)
+
+    def generate_result_code(self, code):
+        self.def_node.generate_execution_code(code)
+        super(LambdaNode, self).generate_result_code(code)
+
 
 class GeneratorExpressionNode(LambdaNode):
     # A generator expression, e.g.  (i for i in range(10))
@@ -5275,11 +5285,11 @@ class GeneratorExpressionNode(LambdaNode):
     binding = False
 
     def analyse_declarations(self, env):
-        self.def_node.no_assignment_synthesis = True
-        self.def_node.analyse_declarations(env)
+        super(GeneratorExpressionNode, self).analyse_declarations(env)
+        # No pymethdef required
+        self.def_node.pymethdef_required = False
         # Force genexpr signature
         self.def_node.entry.signature = TypeSlots.pyfunction_noargs
-        env.add_lambda_def(self.def_node)
 
     def generate_result_code(self, code):
         code.putln(

Cython/Compiler/Nodes.py

@@ -1162,6 +1162,7 @@ class FuncDefNode(StatNode, BlockNode):
     #  entry           Symtab.Entry
     #  needs_closure   boolean        Whether or not this function has inner functions/classes/yield
     #  needs_outer_scope boolean      Whether or not this function requires outer scope
+    #  pymethdef_required boolean     Force Python method struct generation
     #  directive_locals { string : NameNode } locals defined by cython.locals(...)
     # star_arg      PyArgDeclNode or None  * argument
     # starstar_arg  PyArgDeclNode or None  ** argument
@@ -1170,6 +1171,7 @@ class FuncDefNode(StatNode, BlockNode):
     assmt = None
     needs_closure = False
     needs_outer_scope = False
+    pymethdef_required = False
     is_generator = False
     is_generator_body = False
     modifiers = []
@@ -1289,7 +1291,8 @@ class FuncDefNode(StatNode, BlockNode):
         if preprocessor_guard:
             code.putln(preprocessor_guard)
 
-        with_pymethdef = self.needs_assignment_synthesis(env, code)
+        with_pymethdef = (self.needs_assignment_synthesis(env, code) or
+                          self.pymethdef_required)
         if self.py_func:
             self.py_func.generate_function_header(code,
                 with_pymethdef = with_pymethdef,

tests/run/lambda_T723.pyx

+# mode: run
+# ticket: 723
+# tags: lambda
+
+def t723(a):
+    """
+    >>> t723(2)()
+    4
+    >>> t723(2)(3)
+    9
+    """
+    return lambda x=a: x * x