cmd/compile: add ir.ContainsClosure

And use it to unify all codes that need parent/closure checking.

Change-Id: I0b0aa1b007598668dff2c4bee31e21f0fb3830ce
Reviewed-on: https://go-review.googlesource.com/c/go/+/650315
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

3 files changed, 21 insertions, 28 deletions

diff --git a/src/cmd/compile/internal/escape/solve.go b/src/cmd/compile/internal/escape/solve.go
index 32f5a771a3..2002f2fbe4 100644
--- a/src/cmd/compile/internal/escape/solve.go
+++ b/src/cmd/compile/internal/escape/solve.go
@@ -278,7 +278,7 @@ func (b *batch) outlives(l, other *location) bool {
 		//	var u int  // okay to stack allocate
 		//	fn := func() *int { return &u }()
 		//	*fn() = 42
-		if containsClosure(other.curfn, l.curfn) && !l.curfn.ClosureResultsLost() {
+		if ir.ContainsClosure(other.curfn, l.curfn) && !l.curfn.ClosureResultsLost() {
 			return false
 		}
 
@@ -304,24 +304,9 @@ func (b *batch) outlives(l, other *location) bool {
 	//	func() {
 	//		l = new(int) // must heap allocate: outlives call frame (if not inlined)
 	//	}()
-	if containsClosure(l.curfn, other.curfn) {
+	if ir.ContainsClosure(l.curfn, other.curfn) {
 		return true
 	}
 
 	return false
 }
-
-// containsClosure reports whether c is a closure contained within f.
-func containsClosure(f, c *ir.Func) bool {
-	// Common cases.
-	if f == c || c.OClosure == nil {
-		return false
-	}
-
-	for p := c.ClosureParent; p != nil; p = p.ClosureParent {
-		if p == f {
-			return true
-		}
-	}
-	return false
-}
diff --git a/src/cmd/compile/internal/inline/inl.go b/src/cmd/compile/internal/inline/inl.go
index a8809f3682..1b1a9cf338 100644
--- a/src/cmd/compile/internal/inline/inl.go
+++ b/src/cmd/compile/internal/inline/inl.go
@@ -1009,26 +1009,19 @@ func canInlineCallExpr(callerfn *ir.Func, n *ir.CallExpr, callee *ir.Func, bigCa
 		return false, 0, false
 	}
 
-	isClosureParent := func(closure, parent *ir.Func) bool {
-		for p := closure.ClosureParent; p != nil; p = p.ClosureParent {
-			if p == parent {
-				return true
-			}
-		}
-		return false
-	}
-	if isClosureParent(callerfn, callee) {
+	if ir.ContainsClosure(callee, callerfn) {
 		// Can't recursively inline a parent of the closure into itself.
 		if log && logopt.Enabled() {
 			logopt.LogOpt(n.Pos(), "cannotInlineCall", "inline", fmt.Sprintf("recursive call to closure parent: %s, %s", ir.FuncName(callerfn), ir.FuncName(callee)))
 		}
 		return false, 0, false
 	}
-	if isClosureParent(callee, callerfn) {
+
+	if ir.ContainsClosure(callerfn, callee) {
 		// Can't recursively inline a closure if there's a call to the parent in closure body.
 		if ir.Any(callee, func(node ir.Node) bool {
 			if call, ok := node.(*ir.CallExpr); ok {
-				if name, ok := call.Fun.(*ir.Name); ok && isClosureParent(callerfn, name.Func) {
+				if name, ok := call.Fun.(*ir.Name); ok && ir.ContainsClosure(name.Func, callerfn) {
 					return true
 				}
 			}
diff --git a/src/cmd/compile/internal/ir/func.go b/src/cmd/compile/internal/ir/func.go
index 6354da3556..668537c90e 100644
--- a/src/cmd/compile/internal/ir/func.go
+++ b/src/cmd/compile/internal/ir/func.go
@@ -627,3 +627,18 @@ func (fn *Func) DeclareParams(setNname bool) {
 	declareParams(params, PPARAM, "~p", 0)
 	declareParams(results, PPARAMOUT, "~r", len(params))
 }
+
+// ContainsClosure reports whether c is a closure contained within f.
+func ContainsClosure(f, c *Func) bool {
+	// Common cases.
+	if f == c || c.OClosure == nil {
+		return false
+	}
+
+	for p := c.ClosureParent; p != nil; p = p.ClosureParent {
+		if p == f {
+			return true
+		}
+	}
+	return false
+}