commit e3ba8828baf60343316bb68002e94570ee63ad1e
author Cherry Zhang <cherryyz@google.com> Tue May 07 17:09:29 2019 -0400
committer Ian Lance Taylor <iant@golang.org> Wed May 08 04:29:07 2019 +0000
tree 08066747ecf45a00bf8b947fc70f72a638413ac2
parent dc9c1b43753f392fdc2045bcb7a4abaa44fe79f1

compiler: don't add pointer twice to value method of direct interface type

For a direct interface type T with a value method M, its pointer
type (*T)'s method table includes a stub method of M which takes
a (*T) as the receiver instead of a T. However, for the "typ"
field of the method table entry, we added another layer of
indirection, which makes it appear to take a **T, which is wrong.
This causes problems when using reflect.Type.Method to get the
method. This CL fixes the second, incorrect, indirection.

Change-Id: I629018011426a4621d7dd0fb63bdba2f8d109af7
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/175837
Reviewed-by: Ian Lance Taylor <iant@golang.org>

go/types.cc

diff --git a/go/types.cc b/go/types.cc
index 5796d2d..371b65f 100644
--- a/go/types.cc
+++ b/go/types.cc
@@ -3440,14 +3440,15 @@
       vals->push_back(Expression::make_unary(OPERATOR_AND, s, bloc));
     }
 
-  Named_object* no =
-    ((this->points_to() != NULL
-      && this->points_to()->is_direct_iface_type()
-      && m->is_value_method())
-     ? m->iface_stub_object()
-     : (m->needs_stub_method()
-        ? m->stub_object()
-        : m->named_object()));
+  bool use_direct_iface_stub =
+    this->points_to() != NULL
+    && this->points_to()->is_direct_iface_type()
+    && m->is_value_method();
+  Named_object* no = (use_direct_iface_stub
+                      ? m->iface_stub_object()
+                      : (m->needs_stub_method()
+                         ? m->stub_object()
+                         : m->named_object()));
 
   Function_type* mtype;
   if (no->is_function())
@@ -3463,7 +3464,8 @@
 
   ++p;
   go_assert(p->is_field_name("typ"));
-  bool want_pointer_receiver = !only_value_methods && m->is_value_method();
+  bool want_pointer_receiver = (!only_value_methods && m->is_value_method()
+                                && !use_direct_iface_stub);
   nonmethod_type = mtype->copy_with_receiver_as_param(want_pointer_receiver);
   vals->push_back(Expression::make_type_descriptor(nonmethod_type, bloc));