compiler: improvements for type alias handling

    Give an error for an attempt to define a method on an imported type.

    Give an error for each attempt to define a method on a builtin type.

    Adjust error messages to be closer to gc error messages.

    With these changes gccgo passes current tests on dev.typealias branch.

    This changes the errors printed for test/fixedbugs/issue5089.go, but
    the change is an improvement:

        Before:
            fixedbugs/issue5089.go:13:1: error: redefinition of ‘bufio.Buffered’: receiver name changed
             func (b *bufio.Reader) Buffered() int { // ERROR "non-local|redefinition"
             ^
            fixedbugs/issue5089.go:11:13: note: previous definition of ‘bufio.Buffered’ was here
             import "bufio" // GCCGO_ERROR "previous"
                         ^

        Now:
            fixedbugs/issue5089.go:13:7: error: may not define methods on non-local type
             func (b *bufio.Reader) Buffered() int { // ERROR "non-local|redefinition"
                   ^

    Reviewed-on: https://go-review.googlesource.com/35642

From-SVN: r244889

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index f29acdf595d4ef230f388e17b3c846b6509b4012..582a86b0088fa19669ba4c9934f9179fa14446db 100644 (file)
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-fb609ff6d940768cf4db4ab7deb93b2ab686e45d
+5c6c93f58e2aaae186bac5dcde9df1679d4896b1
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

diff --git a/gcc/go/gofrontend/gogo.cc b/gcc/go/gofrontend/gogo.cc
index ad2541c6eee9ae3c6384b788b04b1591fd852636..c5ce5d9ecec9c0152e8ec13437dec6ff67c7a306 100644 (file)
--- a/gcc/go/gofrontend/gogo.cc
+++ b/gcc/go/gofrontend/gogo.cc
@@ -1779,18 +1779,27 @@ Gogo::start_function(const std::string& name, Function_type* type,
 
          while (rtype->named_type() != NULL
                 && rtype->named_type()->is_alias())
-           rtype = rtype->named_type()->real_type();
+           rtype = rtype->named_type()->real_type()->forwarded();
 
          if (rtype->is_error_type())
            ret = Named_object::make_function(name, NULL, function);
          else if (rtype->named_type() != NULL)
            {
-             ret = rtype->named_type()->add_method(name, function);
-             if (!ret->is_function())
+             if (rtype->named_type()->named_object()->package() != NULL)
                {
-                 // Redefinition error.
+                 go_error_at(type->receiver()->location(),
+                             "may not define methods on non-local type");
                  ret = Named_object::make_function(name, NULL, function);
                }
+             else
+               {
+                 ret = rtype->named_type()->add_method(name, function);
+                 if (!ret->is_function())
+                   {
+                     // Redefinition error.
+                     ret = Named_object::make_function(name, NULL, function);
+                   }
+               }
            }
          else if (rtype->forward_declaration_type() != NULL)
            {
@@ -2247,8 +2256,14 @@ Gogo::define_global_names()
          if (global_no->is_type())
            {
              if (no->type_declaration_value()->has_methods())
-               go_error_at(no->location(),
-                           "may not define methods for global type");
+               {
+                 for (std::vector<Named_object*>::const_iterator p =
+                        no->type_declaration_value()->methods()->begin();
+                      p != no->type_declaration_value()->methods()->end();
+                      p++)
+                   go_error_at((*p)->location(),
+                               "may not define methods on non-local type");
+               }
              no->set_type_value(global_no->type_value());
            }
          else

diff --git a/gcc/testsuite/go.test/test/fixedbugs/issue5089.go b/gcc/testsuite/go.test/test/fixedbugs/issue5089.go
index 81b9f0521f96ee01f32537c3348887f325e6f94b..dc393e9b06c5350b05c4471ce36a2a6a11038e7f 100644 (file)
--- a/gcc/testsuite/go.test/test/fixedbugs/issue5089.go
+++ b/gcc/testsuite/go.test/test/fixedbugs/issue5089.go
@@ -1,6 +1,6 @@
 // errorcheck
 
-// Copyright 2013 The Go Authors.  All rights reserved.
+// Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
@@ -8,7 +8,7 @@
 
 package p
 
-import "bufio" // GCCGO_ERROR "previous"
+import "bufio"
 
 func (b *bufio.Reader) Buffered() int { // ERROR "non-local|redefinition"
        return -1