From: Robert Griesemer <gri@golang.org>
Date: Thu, 29 Apr 2021 01:00:16 +0000 (-0700)
Subject: cmd/compile/internal/types2: match compiler error for invalid type alias decl
X-Git-Tag: go1.17beta1~372
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=6afa0ae4e54ec049f291050b82c2a770bb3644b1;p=gostls13.git

cmd/compile/internal/types2: match compiler error for invalid type alias decl

Fixes #45594.

Change-Id: I2fcc784e6908403dd96b009546e1ac2f53b9f0e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/314776
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
---

diff --git a/src/cmd/compile/internal/types2/decl.go b/src/cmd/compile/internal/types2/decl.go
index 178bebe2ec..4966f19892 100644
--- a/src/cmd/compile/internal/types2/decl.go
+++ b/src/cmd/compile/internal/types2/decl.go
@@ -602,7 +602,11 @@ func (check *Checker) typeDecl(obj *TypeName, tdecl *syntax.TypeDecl, def *Named
 	if alias {
 		// type alias declaration
 		if !check.allowVersion(obj.pkg, 1, 9) {
-			check.error(tdecl, "type aliases requires go1.9 or later")
+			if check.conf.CompilerErrorMessages {
+				check.error(tdecl, "type aliases only supported as of -lang=go1.9")
+			} else {
+				check.error(tdecl, "type aliases requires go1.9 or later")
+			}
 		}
 
 		obj.typ = Typ[Invalid]