[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>

1 files changed, 12 insertions, 5 deletions

diff --git a/src/cmd/compile/internal/ir/func.go b/src/cmd/compile/internal/ir/func.go
index 3d4f8c4486..6480becc93 100644
--- a/src/cmd/compile/internal/ir/func.go
+++ b/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)
 	}