1 files changed, 26 insertions, 13 deletions
diff --git a/gcc/go/gofrontend/expressions.h b/gcc/go/gofrontend/expressions.h
index abebbd16961..83bc7241480 100644
--- a/gcc/go/gofrontend/expressions.h
+++ b/gcc/go/gofrontend/expressions.h
@@ -103,6 +103,7 @@ class Expression
     EXPRESSION_TYPE_DESCRIPTOR,
     EXPRESSION_TYPE_INFO,
     EXPRESSION_SLICE_INFO,
+    EXPRESSION_INTERFACE_INFO,
     EXPRESSION_STRUCT_FIELD_OFFSET,
     EXPRESSION_MAP_DESCRIPTOR,
     EXPRESSION_LABEL_ADDR
@@ -356,6 +357,21 @@ class Expression
   static Expression*
   make_slice_info(Expression* slice, Slice_info, Location);
 
+
+  // Make an expression that evaluates to some characteristic of a
+  // interface.  For simplicity, the enum values must match the field indexes
+  // of a non-empty interface in the underlying struct.
+  enum Interface_info
+    {
+      // The methods of an interface.
+      INTERFACE_INFO_METHODS,
+      // The first argument to pass to an interface method.
+      INTERFACE_INFO_OBJECT
+    };
+
+  static Expression*
+  make_interface_info(Expression* iface, Interface_info, Location);
+
   // Make an expression which evaluates to the offset of a field in a
   // struct.  This is only used for type descriptors, so there is no
   // location parameter.
@@ -1508,10 +1524,9 @@ class Call_expression : public Expression
   bool
   check_argument_type(int, const Type*, const Type*, Location, bool);
 
-  tree
-  interface_method_function(Translate_context*,
-			    Interface_field_reference_expression*,
-			    tree*);
+  Expression*
+  interface_method_function(Interface_field_reference_expression*,
+			    Expression**);
 
   tree
   set_results(Translate_context*, tree);
@@ -2115,16 +2130,14 @@ class Interface_field_reference_expression : public Expression
   static Named_object*
   create_thunk(Gogo*, Interface_type* type, const std::string& name);
 
-  // Return a tree for the pointer to the function to call, given a
-  // tree for the expression.
-  tree
-  get_function_tree(Translate_context*, tree);
+  // Return an expression for the pointer to the function to call.
+  Expression*
+  get_function();
 
-  // Return a tree for the first argument to pass to the interface
-  // function, given a tree for the expression.  This is the real
-  // object associated with the interface object.
-  tree
-  get_underlying_object_tree(Translate_context*, tree);
+  // Return an expression for the first argument to pass to the interface
+  // function.  This is the real object associated with the interface object.
+  Expression*
+  get_underlying_object();
 
  protected:
   int