[dev.unified] test: break escape_iface.go into unified/nounified variants

The assignment `sink, *(&ok) = y.(int)` should (and does) escape a
value to the heap, but this detail is missed because the implicit
conversion of the multi-value expression `y.(int)` isn't visible to
escape analysis (because it's not inserted until desugaring during
walk).

For Unified IR, I plan to apply this desugaring earlier (because it's
necessary for correct dictionary handling), which means we'll
now (correctly) report the heap escape.

Due to limitations of the $GOROOT/test harness, the easiest way to
handle that GOEXPERIMENT=unified gets this right while
GOEXPERIMENT=nounified does not is to split the test case into
separate files. Hence this CL.

Change-Id: I91f3a6c015cbc646ab018747e152cac2874cf24c
Reviewed-on: https://go-review.googlesource.com/c/go/+/415241
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

diff --git a/test/escape_iface.go b/test/escape_iface.go
index dba08e3cb33b308fea18137d288af1a8bddf8045..986228129a698c18ae638552d8c84b1c631c5c2b 100644 (file)
--- a/test/escape_iface.go
+++ b/test/escape_iface.go
@@ -234,16 +234,6 @@ func dotTypeEscape2() { // #13805, #15796
                *(&v) = x.(int)
                *(&v), *(&ok) = y.(int)
        }
-       {
-               i := 0
-               j := 0
-               var ok bool
-               var x interface{} = i // ERROR "i does not escape"
-               var y interface{} = j // ERROR "j does not escape"
-
-               sink = x.(int) // ERROR "x.\(int\) escapes to heap"
-               sink, *(&ok) = y.(int)
-       }
        {
                i := 0 // ERROR "moved to heap: i"
                j := 0 // ERROR "moved to heap: j"

diff --git a/test/escape_iface_nounified.go b/test/escape_iface_nounified.go
new file mode 100644 (file)
index 0000000..1d267bc
--- /dev/null
+++ b/test/escape_iface_nounified.go
@@ -0,0 +1,25 @@
+// errorcheck -0 -m -l
+//go:build !goexperiment.unified
+// +build !goexperiment.unified
+
+// Copyright 2015 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 escape
+
+var sink interface{}
+
+func dotTypeEscape2() { // #13805, #15796
+       {
+               i := 0
+               j := 0
+               var ok bool
+               var x interface{} = i // ERROR "i does not escape"
+               var y interface{} = j // ERROR "j does not escape"
+
+               sink = x.(int) // ERROR "x.\(int\) escapes to heap"
+               // BAD: should be "y.\(int\) escapes to heap" too
+               sink, *(&ok) = y.(int)
+       }
+}

diff --git a/test/escape_iface_unified.go b/test/escape_iface_unified.go
new file mode 100644 (file)
index 0000000..7ac8e00
--- /dev/null
+++ b/test/escape_iface_unified.go
@@ -0,0 +1,25 @@
+// errorcheck -0 -m -l
+//go:build goexperiment.unified
+// +build goexperiment.unified
+
+// Copyright 2015 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 escape
+
+var sink interface{}
+
+func dotTypeEscape2() { // #13805, #15796
+       {
+               i := 0
+               j := 0
+               var ok bool
+               var x interface{} = i // ERROR "i does not escape"
+               var y interface{} = j // ERROR "j does not escape"
+
+               sink = x.(int) // ERROR "x.\(int\) escapes to heap"
+               // BAD: should be "y.\(int\) escapes to heap" too
+               sink, *(&ok) = y.(int)
+       }
+}