From: Robert Griesemer <gri@golang.org>
Date: Wed, 14 Apr 2021 20:10:34 +0000 (-0700)
Subject: cmd/compile/internal/syntax: fix error message for ... without type
X-Git-Tag: go1.17beta1~621
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=a63ff398d5;p=gostls13.git

cmd/compile/internal/syntax: fix error message for ... without type

Only complain about missing type; leave it to type-checking
to decide whether "..." is permitted in the first place.

Fixes #43674.

Change-Id: Icbc8f084e364fe3ac16076406a134354219c08d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/310209
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
---

diff --git a/src/cmd/compile/internal/syntax/parser.go b/src/cmd/compile/internal/syntax/parser.go
index 026297432d..80250212dd 100644
--- a/src/cmd/compile/internal/syntax/parser.go
+++ b/src/cmd/compile/internal/syntax/parser.go
@@ -1836,7 +1836,7 @@ func (p *parser) paramDeclOrNil(name *Name) *Field {
 		t.Elem = p.typeOrNil()
 		if t.Elem == nil {
 			t.Elem = p.badExpr()
-			p.syntaxError("final argument in variadic function missing type")
+			p.syntaxError("... is missing type")
 		}
 		f.Type = t
 		return f
diff --git a/src/cmd/compile/internal/syntax/testdata/issue43674.src b/src/cmd/compile/internal/syntax/testdata/issue43674.src
new file mode 100644
index 0000000000..51c692ae69
--- /dev/null
+++ b/src/cmd/compile/internal/syntax/testdata/issue43674.src
@@ -0,0 +1,13 @@
+// Copyright 2021 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.
+
+package p
+
+func _(... /* ERROR [.][.][.] is missing type */ )
+func _(... /* ERROR [.][.][.] is missing type */ , int)
+
+func _(a, b ... /* ERROR [.][.][.] is missing type */ )
+func _(a, b ... /* ERROR [.][.][.] is missing type */ , x int)
+
+func _()(... /* ERROR [.][.][.] is missing type */ )
diff --git a/test/fixedbugs/bug228.go b/test/fixedbugs/bug228.go
index f7ac670689..50e895917f 100644
--- a/test/fixedbugs/bug228.go
+++ b/test/fixedbugs/bug228.go
@@ -8,7 +8,7 @@ package main
 
 func f(x int, y ...int)	// ok
 
-func g(x int, y float32) (...)	// ERROR "[.][.][.]" "final argument"
+func g(x int, y float32) (...)	// ERROR "[.][.][.]"
 
 func h(x, y ...int)		// ERROR "[.][.][.]"