Go patch committed: Better error for unknown name in package

[Ian Lance Taylor]

This patch improves the error message that the Go frontend issues when
an unknown name in a package is used as type.  It also fixes some
followon errors.  Bootstrapped and ran Go testsuite on
x86_64-unknown-linux-gnu.  Committed to mainline.

Ian


diff -r 4e6476a9ca36 go/expressions.cc
--- a/go/expressions.cc	Tue Sep 20 15:05:43 2011 -0700
+++ b/go/expressions.cc	Tue Sep 20 15:32:18 2011 -0700
@@ -9730,7 +9730,10 @@
   if (fntype == NULL)
     {
       if (ce->issue_error())
-	this->report_error(_("expected function"));    
+	{
+	  if (!ce->fn()->type()->is_error())
+	    this->report_error(_("expected function"));
+	}
       this->set_is_error();
       return Type::make_error_type();
     }
@@ -10043,7 +10046,9 @@
     this->report_error(_("index must be integer"));
   if (this->end_ != NULL
       && this->end_->type()->integer_type() == NULL
-      && !this->end_->is_nil_expression())
+      && !this->end_->type()->is_error()
+      && !this->end_->is_nil_expression()
+      && !this->end_->is_error_expression())
     this->report_error(_("slice end must be integer"));
 
   Array_type* array_type = this->array_->type()->array_type();
diff -r 4e6476a9ca36 go/parse.cc
--- a/go/parse.cc	Tue Sep 20 15:05:43 2011 -0700
+++ b/go/parse.cc	Tue Sep 20 15:32:18 2011 -0700
@@ -335,10 +335,17 @@
   bool ok = true;
   if (named_object == NULL)
     {
-      if (package != NULL)
-	ok = false;
+      if (package == NULL)
+	named_object = this->gogo_->add_unknown_name(name, location);
       else
-	named_object = this->gogo_->add_unknown_name(name, location);
+	{
+	  const std::string& packname(package->package_value()->name());
+	  error_at(location, "reference to undefined identifer %<%s.%s%>",
+		   Gogo::message_name(packname).c_str(),
+		   Gogo::message_name(name).c_str());
+	  issue_error = false;
+	  ok = false;
+	}
     }
   else if (named_object->is_type())
     {