cmd/compile: unnamed parameters do not escape

Fixes #19687

Change-Id: I2e4769b4ec5812506df4ac5dc6bc6a7c5774ecb0
Reviewed-on: https://go-review.googlesource.com/38600
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/test/escape5.go b/test/escape5.go
index c4bf17b2ac..7d6ef554a5 100644
--- a/test/escape5.go
+++ b/test/escape5.go
@@ -9,6 +9,8 @@
 
 package foo
 
+import "runtime"
+
 func noleak(p *int) int { // ERROR "p does not escape"
 	return *p
 }
@@ -149,3 +151,15 @@ func f10() {
 	var y = make([]byte, 1<<30) // ERROR "make\(\[\]byte, 1 << 30\) escapes to heap"
 	_ = x[0] + y[0]
 }
+
+// Test for issue 19687 (passing to unnamed parameters does not escape).
+func f11(**int) {
+}
+func f12(_ **int) {
+}
+func f13() {
+	var x *int
+	f11(&x)               // ERROR "&x does not escape"
+	f12(&x)               // ERROR "&x does not escape"
+	runtime.KeepAlive(&x) // ERROR "&x does not escape"
+}