From: Ian Lance Taylor <iant@golang.org>
Date: Sat, 28 Nov 2020 20:41:06 +0000 (-0800)
Subject: compiler: better error messages for missing interface method
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=38f10841817a9fee28ee97c7115b6f4d24f5245d;p=gcc.git

compiler: better error messages for missing interface method

For golang/go#10700

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/273886
---

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index c14a10f1265..af4d0526b2f 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-534fb907c821b052dc430330708d7fa555b91fe3
+68b1c7659a6b25d537a4ff3365ab070fa6215b0b
 
 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/types.cc b/gcc/go/gofrontend/types.cc
index 286ecc16366..23d1647c1fa 100644
--- a/gcc/go/gofrontend/types.cc
+++ b/gcc/go/gofrontend/types.cc
@@ -12052,6 +12052,15 @@ Type::bind_field_or_method(Gogo* gogo, const Type* type, Expression* expr,
 		    ambig2.c_str());
       else if (found_pointer_method)
 	go_error_at(location, "method requires a pointer receiver");
+      else if (it != NULL && it->is_empty())
+	go_error_at(location,
+		    "reference to method %qs in interface with no methods",
+		    Gogo::message_name(name).c_str());
+      else if (it == NULL && type->deref()->interface_type() != NULL)
+	go_error_at(location,
+		    ("reference to method %qs in type that is "
+		     "pointer to interface, not interface"),
+		    Gogo::message_name(name).c_str());
       else if (nt == NULL && st == NULL && it == NULL)
 	go_error_at(location,
 		    ("reference to field %qs in object which "
diff --git a/gcc/testsuite/go.test/test/fixedbugs/bug340.go b/gcc/testsuite/go.test/test/fixedbugs/bug340.go
index d996ab64cd4..8c543c98d97 100644
--- a/gcc/testsuite/go.test/test/fixedbugs/bug340.go
+++ b/gcc/testsuite/go.test/test/fixedbugs/bug340.go
@@ -1,6 +1,6 @@
 // errorcheck
 
-// Copyright 2011 The Go Authors.  All rights reserved.
+// Copyright 2011 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.
 
@@ -12,6 +12,6 @@ func main() {
 	var x interface{}
 	switch t := x.(type) {
 	case 0:		// ERROR "type"
-		t.x = 1 // ERROR "type interface \{\}|reference to undefined field or method"
+		t.x = 1 // ERROR "type interface \{\}|reference to undefined field or method|interface with no methods"
 	}
 }