[dev.typeparams] cmd/compile: simplify NewClosureFunc

I initially made NewClosureFunc take an "outerfn *Func" parameter
because I was planning on having it handle closure naming, until
remembering that naming needs to wait until typecheck for noder.

We don't actually need the *Func yet, just to know whether it's
non-nil. So change the parameter to a bool, which simplifies callers a
little.

Change-Id: Ie83ee4a1ed0571ac6d3879ffd8474c6c3c1a9ff9
Reviewed-on: https://go-review.googlesource.com/c/go/+/327450
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>

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

@@ -1153,13 +1153,8 @@ func (subst *inlsubst) closure(n *ir.ClosureExpr) ir.Node {
 
 	//fmt.Printf("Inlining func %v with closure into %v\n", subst.fn, ir.FuncName(ir.CurFunc))
 
-	outerfunc := subst.newclofn
-	if outerfunc == nil {
-		outerfunc = ir.CurFunc
-	}
-
 	oldfn := n.Func
-	newfn := ir.NewClosureFunc(oldfn.Pos(), outerfunc)
+	newfn := ir.NewClosureFunc(oldfn.Pos(), true)
 
 	// Ntype can be nil for -G=3 mode.
 	if oldfn.Nname.Ntype != nil {

src/cmd/compile/internal/ir/func.go

@@ -343,11 +343,13 @@ func closureName(outerfn *Func) *types.Sym {
 	return pkg.Lookup(fmt.Sprintf("%s.%s%d", outer, prefix, *gen))
 }
 
-// NewClosureFunc creates a new Func to represent a function literal
-// within outerfn.
-func NewClosureFunc(pos src.XPos, outerfn *Func) *Func {
+// NewClosureFunc creates a new Func to represent a function literal.
+// If hidden is true, then the closure is marked hidden (i.e., as a
+// function literal contained within another function, rather than a
+// package-scope variable initialization expression).
+func NewClosureFunc(pos src.XPos, hidden bool) *Func {
 	fn := NewFunc(pos)
-	fn.SetIsHiddenClosure(outerfn != nil)
+	fn.SetIsHiddenClosure(hidden)
 
 	fn.Nname = NewNameAt(pos, BlankNode.Sym())
 	fn.Nname.Func = fn
@@ -361,7 +363,12 @@ func NewClosureFunc(pos src.XPos, outerfn *Func) *Func {
 // NameClosure generates a unique for the given function literal,
 // which must have appeared within outerfn.
 func NameClosure(clo *ClosureExpr, outerfn *Func) {
-	name := clo.Func.Nname
+	fn := clo.Func
+	if fn.IsHiddenClosure() != (outerfn != nil) {
+		base.FatalfAt(clo.Pos(), "closure naming inconsistency: hidden %v, but outer %v", fn.IsHiddenClosure(), outerfn)
+	}
+
+	name := fn.Nname
 	if !IsBlank(name) {
 		base.FatalfAt(clo.Pos(), "closure already named: %v", name)
 	}

src/cmd/compile/internal/noder/expr.go

@@ -373,7 +373,7 @@ func (g *irgen) compLit(typ types2.Type, lit *syntax.CompositeLit) ir.Node {
 }
 
 func (g *irgen) funcLit(typ2 types2.Type, expr *syntax.FuncLit) ir.Node {
-	fn := ir.NewClosureFunc(g.pos(expr), ir.CurFunc)
+	fn := ir.NewClosureFunc(g.pos(expr), ir.CurFunc != nil)
 	ir.NameClosure(fn.OClosure, ir.CurFunc)
 
 	typ := g.typ(typ2)

src/cmd/compile/internal/noder/noder.go

@@ -1803,7 +1803,7 @@ func fakeRecv() *ir.Field {
 }
 
 func (p *noder) funcLit(expr *syntax.FuncLit) ir.Node {
-	fn := ir.NewClosureFunc(p.pos(expr), ir.CurFunc)
+	fn := ir.NewClosureFunc(p.pos(expr), ir.CurFunc != nil)
 	fn.Nname.Ntype = p.typeExpr(expr.Type)
 
 	p.funcBody(fn, expr.Body)

src/cmd/compile/internal/noder/stencil.go

@@ -280,7 +280,7 @@ func (g *irgen) buildClosure(outer *ir.Func, x ir.Node) ir.Node {
 	//   }
 
 	// Make a new internal function.
-	fn := ir.NewClosureFunc(pos, outer)
+	fn := ir.NewClosureFunc(pos, outer != nil)
 	ir.NameClosure(fn.OClosure, outer)
 
 	// This is the dictionary we want to use.
@@ -857,7 +857,7 @@ func (subst *subster) node(n ir.Node) ir.Node {
 			// Need to duplicate x.Func.Nname, x.Func.Dcl, x.Func.ClosureVars, and
 			// x.Func.Body.
 			oldfn := x.Func
-			newfn := ir.NewClosureFunc(oldfn.Pos(), subst.newf)
+			newfn := ir.NewClosureFunc(oldfn.Pos(), subst.newf != nil)
 			ir.NameClosure(newfn.OClosure, subst.newf)
 
 			newfn.SetClosureCalled(oldfn.ClosureCalled())

src/cmd/compile/internal/typecheck/iimport.go

@@ -1283,7 +1283,7 @@ func (r *importReader) node() ir.Node {
 
 		// All the remaining code below is similar to (*noder).funcLit(), but
 		// with Dcls and ClosureVars lists already set up
-		fn := ir.NewClosureFunc(pos, r.curfn)
+		fn := ir.NewClosureFunc(pos, true)
 		fn.Nname.SetType(typ)
 
 		cvars := make([]*ir.Name, r.int64())

src/cmd/compile/internal/walk/order.go

@@ -1704,9 +1704,7 @@ func (o *orderState) wrapGoDefer(n *ir.GoDeferStmt) {
 	}
 
 	// Create a new no-argument function that we'll hand off to defer.
-	outerfn := ir.CurFunc
-
-	fn := ir.NewClosureFunc(base.Pos, outerfn)
+	fn := ir.NewClosureFunc(base.Pos, true)
 	fn.Nname.SetType(types.NewSignature(types.LocalPkg, nil, nil, nil, nil))
 	fn.SetWrapper(true)
 
@@ -1752,7 +1750,7 @@ func (o *orderState) wrapGoDefer(n *ir.GoDeferStmt) {
 
 	// Finalize body, register function on the main decls list.
 	fn.Body = []ir.Node{newcall}
-	ir.FinishCaptureNames(n.Pos(), outerfn, fn)
+	ir.FinishCaptureNames(n.Pos(), ir.CurFunc, fn)
 
 	// Create closure expr
 	clo := typecheck.Expr(fn.OClosure).(*ir.ClosureExpr)