cmd/compile: remove unneeded calls to typecheck in noder2

Remove unneeded calls to typecheck in noder2 associated with g.use() and
g.obj(). These routines are already setting the types2-derived type
correctly for ONAME nodes, and there is no typechecker1-related
transformations related to ONAME nodes, other than making sure that
newly created closure variables have their type set.

Tested through normal -G=3 testing in all.bash (all of go/tests).

Change-Id: I1b790ab9948959685fca3a768401458201833671
Reviewed-on: https://go-review.googlesource.com/c/go/+/303029
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>

2 files changed, 18 insertions, 9 deletions

diff --git a/src/cmd/compile/internal/noder/expr.go b/src/cmd/compile/internal/noder/expr.go
index 1ca5552879..957295bdf0 100644
--- a/src/cmd/compile/internal/noder/expr.go
+++ b/src/cmd/compile/internal/noder/expr.go
@@ -30,7 +30,6 @@ func (g *irgen) expr(expr syntax.Expr) ir.Node {
 	}
 	switch {
 	case tv.IsBuiltin():
-		// TODO(mdempsky): Handle in CallExpr?
 		return g.use(expr.(*syntax.Name))
 	case tv.IsType():
 		return ir.TypeNode(g.typ(tv.Type))
@@ -82,8 +81,7 @@ func (g *irgen) expr0(typ types2.Type, expr syntax.Expr) ir.Node {
 		if _, isNil := g.info.Uses[expr].(*types2.Nil); isNil {
 			return Nil(pos, g.typ(typ))
 		}
-		// TODO(mdempsky): Remove dependency on typecheck.Expr.
-		return typecheck.Expr(g.use(expr))
+		return g.use(expr)
 
 	case *syntax.CompositeLit:
 		return g.compLit(typ, expr)
@@ -157,8 +155,7 @@ func (g *irgen) expr0(typ types2.Type, expr syntax.Expr) ir.Node {
 		// Qualified identifier.
 		if name, ok := expr.X.(*syntax.Name); ok {
 			if _, ok := g.info.Uses[name].(*types2.PkgName); ok {
-				// TODO(mdempsky): Remove dependency on typecheck.Expr.
-				return typecheck.Expr(g.use(expr.Sel))
+				return g.use(expr.Sel)
 			}
 		}
 		return g.selectorExpr(pos, typ, expr)
diff --git a/src/cmd/compile/internal/noder/object.go b/src/cmd/compile/internal/noder/object.go
index b4e5c022db..6c8ed4af97 100644
--- a/src/cmd/compile/internal/noder/object.go
+++ b/src/cmd/compile/internal/noder/object.go
@@ -22,16 +22,26 @@ func (g *irgen) def(name *syntax.Name) (*ir.Name, types2.Object) {
 	return g.obj(obj), obj
 }
 
+// use returns the Name node associated with the use of name. The returned node
+// will have the correct type and be marked as typechecked.
 func (g *irgen) use(name *syntax.Name) *ir.Name {
-	obj, ok := g.info.Uses[name]
+	obj2, ok := g.info.Uses[name]
 	if !ok {
 		base.FatalfAt(g.pos(name), "unknown name %v", name)
 	}
-	return ir.CaptureName(g.pos(obj), ir.CurFunc, g.obj(obj))
+	obj := ir.CaptureName(g.pos(obj2), ir.CurFunc, g.obj(obj2))
+	if obj.Defn != nil && obj.Defn.Op() == ir.ONAME {
+		// If CaptureName created a closure variable, then transfer the
+		// type of the captured name to the new closure variable.
+		obj.SetTypecheck(1)
+		obj.SetType(obj.Defn.Type())
+	}
+	return obj
 }
 
-// obj returns the Name that represents the given object. If no such
-// Name exists yet, it will be implicitly created.
+// obj returns the Name that represents the given object. If no such Name exists
+// yet, it will be implicitly created. The returned node will have the correct
+// type and be marked as typechecked.
 //
 // For objects declared at function scope, ir.CurFunc must already be
 // set to the respective function when the Name is created.
@@ -45,6 +55,7 @@ func (g *irgen) obj(obj types2.Object) *ir.Name {
 		}
 		n := typecheck.Resolve(ir.NewIdent(src.NoXPos, sym))
 		if n, ok := n.(*ir.Name); ok {
+			n.SetTypecheck(1)
 			return n
 		}
 		base.FatalfAt(g.pos(obj), "failed to resolve %v", obj)
@@ -117,6 +128,7 @@ func (g *irgen) obj(obj types2.Object) *ir.Name {
 	}
 
 	g.objs[obj] = name
+	name.SetTypecheck(1)
 	return name
 }