From d4d2a98fb267ed59fad4a1d2e7bfe92ac7f6a071 Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <ian@gcc.gnu.org>
Date: Wed, 19 Jan 2011 05:38:41 +0000
Subject: [PATCH] Don't crash using value of something with no value.

From-SVN: r168982
---
 gcc/go/gofrontend/types.cc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/gcc/go/gofrontend/types.cc b/gcc/go/gofrontend/types.cc
index dd0a861d49f..840de2ba82f 100644
--- a/gcc/go/gofrontend/types.cc
+++ b/gcc/go/gofrontend/types.cc
@@ -482,6 +482,15 @@ bool
 Type::are_assignable(const Type* lhs, const Type* rhs, std::string* reason)
 {
   // Do some checks first.  Make sure the types are defined.
+  if (rhs != NULL
+      && rhs->forwarded()->forward_declaration_type() == NULL
+      && rhs->is_void_type())
+    {
+      if (reason != NULL)
+	*reason = "non-value used as value";
+      return false;
+    }
+
   if (lhs != NULL && lhs->forwarded()->forward_declaration_type() == NULL)
     {
       // Any value may be assigned to the blank identifier.