cmd/compile: workaround inlining of closures with range statements

ORANGE is still not inlineable now. This CL is correct only when the range statement is statically dead, and thus not counted during the inline budget check.
If we support range statements in inlining closures in the future, may require additional processing.

Fixes #48033.

Change-Id: I28f5755c28cfa27e41daef9eff2ae332059909bb
Reviewed-on: https://go-review.googlesource.com/c/go/+/345436
Trust: Cherry Mui <[email protected]>
Reviewed-by: Keith Randall <[email protected]>

src/cmd/compile/internal/inline/inl.go

@@ -1061,6 +1061,8 @@ func (subst *inlsubst) clovar(n *ir.Name) *ir.Name {
  m.Defn = &subst.defnMarker
  case *ir.TypeSwitchGuard:
  // TODO(mdempsky): Set m.Defn properly. See discussion on #45743.
+ case *ir.RangeStmt:
+ // TODO: Set m.Defn properly if we support inlining range statement in the future.
  default:
  base.FatalfAt(n.Pos(), "unexpected Defn: %+v", defn)
  }

test/fixedbugs/issue48033.go

@@ -0,0 +1,40 @@
+// compile
+
+// 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 main
+
+import (
+ "fmt"
+ "strings"
+)
+
+type app struct {
+ Name string
+}
+
+func bug() func() {
+ return func() {
+
+ // the issue is this if true block
+ if true {
+ return
+ }
+
+ var xx = []app{}
+ var gapp app
+ for _, app := range xx {
+ if strings.ToUpper("") == app.Name {
+ fmt.Printf("%v\n", app)
+ gapp = app
+ }
+ }
+ fmt.Println(gapp)
+ }
+}
+
+func main() {
+ bug()
+}