cmd/compile: make for loops with range statements not terminating
Fixes #49003
Change-Id: If09c6f028dce5440b1be238612653ffdd626113a
Reviewed-on: https://go-review.googlesource.com/c/go/+/356189
Trust: Keith Randall <khr@golang.org>
Reviewed-by: roger peppe <rogpeppe@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
diff --git a/doc/go_spec.html b/doc/go_spec.html
index c8051f5..46eebb5 100644
--- a/doc/go_spec.html
+++ b/doc/go_spec.html
@@ -1,6 +1,6 @@
<!--{
"Title": "The Go Programming Language Specification",
- "Subtitle": "Version of Sep 16, 2021",
+ "Subtitle": "Version of Oct 15, 2021",
"Path": "/ref/spec"
}-->
@@ -4598,7 +4598,8 @@
A <a href="#For_statements">"for" statement</a> in which:
<ul>
<li>there are no "break" statements referring to the "for" statement, and</li>
- <li>the loop condition is absent.</li>
+ <li>the loop condition is absent, and</li>
+ <li>the "for" statement does not use a range clause.</li>
</ul>
</li>
diff --git a/src/cmd/compile/internal/types2/return.go b/src/cmd/compile/internal/types2/return.go
index 204e456..6c3e184 100644
--- a/src/cmd/compile/internal/types2/return.go
+++ b/src/cmd/compile/internal/types2/return.go
@@ -62,6 +62,11 @@
return true
case *syntax.ForStmt:
+ if _, ok := s.Init.(*syntax.RangeClause); ok {
+ // Range clauses guarantee that the loop terminates,
+ // so the loop is not a terminating statement. See issue 49003.
+ break
+ }
if s.Cond == nil && !hasBreak(s.Body, label, true) {
return true
}
diff --git a/test/fixedbugs/issue49003.go b/test/fixedbugs/issue49003.go
new file mode 100644
index 0000000..da6c19b
--- /dev/null
+++ b/test/fixedbugs/issue49003.go
@@ -0,0 +1,12 @@
+// errorcheck
+
+// 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 f(s string) int {
+ for range s {
+ }
+} // ERROR "missing return"
