[release-branch.go1.20] cmd/compile: fix unsafe.{SliceData,StringData} escape analysi...

Updates #57823
Updates #57854

Change-Id: I54654d3ecb20b75afa9052c5c9db2072a86188d4
Reviewed-on: https://go-review.googlesource.com/c/go/+/461759
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/461760

diff --git a/src/cmd/compile/internal/escape/call.go b/src/cmd/compile/internal/escape/call.go
index 4f602ca15fe77948e94bad7dca0a0a6bf524e880..e2235520e5cd730e13bdb8945b7c01dcec65cbee 100644 (file)
--- a/src/cmd/compile/internal/escape/call.go
+++ b/src/cmd/compile/internal/escape/call.go
@@ -180,10 +180,14 @@ func (e *escape) callCommon(ks []hole, call ir.Node, init *ir.Nodes, wrapper *ir
                        argument(e.discardHole(), &call.Args[i])
                }
 
-       case ir.OLEN, ir.OCAP, ir.OREAL, ir.OIMAG, ir.OCLOSE, ir.OUNSAFESTRINGDATA, ir.OUNSAFESLICEDATA:
+       case ir.OLEN, ir.OCAP, ir.OREAL, ir.OIMAG, ir.OCLOSE:
                call := call.(*ir.UnaryExpr)
                argument(e.discardHole(), &call.X)
 
+       case ir.OUNSAFESTRINGDATA, ir.OUNSAFESLICEDATA:
+               call := call.(*ir.UnaryExpr)
+               argument(ks[0], &call.X)
+
        case ir.OUNSAFEADD, ir.OUNSAFESLICE, ir.OUNSAFESTRING:
                call := call.(*ir.BinaryExpr)
                argument(ks[0], &call.X)

diff --git a/test/fixedbugs/issue57823.go b/test/fixedbugs/issue57823.go
new file mode 100644 (file)
index 0000000..d6708f6
--- /dev/null
+++ b/test/fixedbugs/issue57823.go
@@ -0,0 +1,76 @@
+// run
+
+// Copyright 2023 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 main
+
+import (
+       "runtime"
+       "unsafe"
+)
+
+//go:noinline
+func g(x *byte) *byte { return x }
+
+func main() {
+       slice()
+       str("AAAAAAAA", "BBBBBBBBB")
+}
+
+func wait(done <-chan struct{}) bool {
+       for i := 0; i < 10; i++ {
+               runtime.GC()
+               select {
+               case <-done:
+                       return true
+               default:
+               }
+       }
+       return false
+}
+
+func slice() {
+       s := make([]byte, 100)
+       s[0] = 1
+       one := unsafe.SliceData(s)
+
+       done := make(chan struct{})
+       runtime.SetFinalizer(one, func(*byte) { close(done) })
+
+       h := g(one)
+
+       if wait(done) {
+               panic("GC'd early")
+       }
+
+       if *h != 1 {
+               panic("lost one")
+       }
+
+       if !wait(done) {
+               panic("never GC'd")
+       }
+}
+
+var strDone = make(chan struct{})
+
+//go:noinline
+func str(x, y string) {
+       s := x + y // put in temporary on stack
+       p := unsafe.StringData(s)
+       runtime.SetFinalizer(p, func(*byte) { close(strDone) })
+
+       if wait(strDone) {
+               panic("GC'd early")
+       }
+
+       if *p != 'A' {
+               panic("lost p")
+       }
+
+       if !wait(strDone) {
+               panic("never GC'd")
+       }
+}