cmd/compile: more error position tests for the typechecker

This change adds line position tests for several yyerror calls in the
typechecker that are currently not tested in any way.

Untested yyerror calls were found by replacing them with

  yerrorl(src.NoXPos, ...)

(thus destroying position information in the error), and then running
the test suite. No failures means no test coverage for the relevant
yyerror call.

For #19683

Change-Id: Iedb3d2f02141b332e9bfa76dbf5ae930ad2fddc3
Reviewed-on: https://go-review.googlesource.com/41477
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/test/append1.go b/test/append1.go
new file mode 100644
index 0000000000..6d42368e42
--- /dev/null
+++ b/test/append1.go
@@ -0,0 +1,20 @@
+// errorcheck
+
+// Copyright 2017 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.
+
+// Verify that append arguments requirements are enforced by the
+// compiler.
+
+package main
+
+func main() {
+
+	s := make([]int, 8)
+
+	_ = append()           // ERROR "missing arguments to append"
+	_ = append(s...)       // ERROR "cannot use ... on first argument"
+	_ = append(s, 2, s...) // ERROR "too many arguments to append"
+
+}