[dev.regabi] cmd/compile: prefer types constructors over typecheck

Similar to the earlier mkbuiltin cleanup, there's a bunch of code that
calls typecheck.NewFuncType or typecheck.NewStructType, which can now
just call types.NewSignature and types.NewStruct, respectively.

Passes toolstash -cmp.

Change-Id: Ie6e09f1a7efef84b9a2bb5daa7087a6879979668
Reviewed-on: https://go-review.googlesource.com/c/go/+/279955
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>

2 files changed, 22 insertions, 26 deletions

diff --git a/src/cmd/compile/internal/typecheck/dcl.go b/src/cmd/compile/internal/typecheck/dcl.go
index 9f66d0fa17..bfdd76ba10 100644
--- a/src/cmd/compile/internal/typecheck/dcl.go
+++ b/src/cmd/compile/internal/typecheck/dcl.go
@@ -676,30 +676,26 @@ func autotmpname(n int) string {
 
 // f is method type, with receiver.
 // return function type, receiver as first argument (or not).
-func NewMethodType(f *types.Type, receiver *types.Type) *types.Type {
-	inLen := f.Params().Fields().Len()
-	if receiver != nil {
-		inLen++
+func NewMethodType(sig *types.Type, recv *types.Type) *types.Type {
+	nrecvs := 0
+	if recv != nil {
+		nrecvs++
 	}
-	in := make([]*ir.Field, 0, inLen)
 
-	if receiver != nil {
-		d := ir.NewField(base.Pos, nil, nil, receiver)
-		in = append(in, d)
+	params := make([]*types.Field, nrecvs+sig.Params().Fields().Len())
+	if recv != nil {
+		params[0] = types.NewField(base.Pos, nil, recv)
 	}
-
-	for _, t := range f.Params().Fields().Slice() {
-		d := ir.NewField(base.Pos, nil, nil, t.Type)
-		d.IsDDD = t.IsDDD()
-		in = append(in, d)
+	for i, param := range sig.Params().Fields().Slice() {
+		d := types.NewField(base.Pos, nil, param.Type)
+		d.SetIsDDD(param.IsDDD())
+		params[nrecvs+i] = d
 	}
 
-	outLen := f.Results().Fields().Len()
-	out := make([]*ir.Field, 0, outLen)
-	for _, t := range f.Results().Fields().Slice() {
-		d := ir.NewField(base.Pos, nil, nil, t.Type)
-		out = append(out, d)
+	results := make([]*types.Field, sig.Results().Fields().Len())
+	for i, t := range sig.Results().Fields().Slice() {
+		results[i] = types.NewField(base.Pos, nil, t.Type)
 	}
 
-	return NewFuncType(nil, in, out)
+	return types.NewSignature(types.LocalPkg, nil, params, results)
 }
diff --git a/src/cmd/compile/internal/typecheck/func.go b/src/cmd/compile/internal/typecheck/func.go
index 99d81dcede..fdac719ad9 100644
--- a/src/cmd/compile/internal/typecheck/func.go
+++ b/src/cmd/compile/internal/typecheck/func.go
@@ -73,17 +73,17 @@ func ClosureType(clo *ir.ClosureExpr) *types.Type {
 	// The information appears in the binary in the form of type descriptors;
 	// the struct is unnamed so that closures in multiple packages with the
 	// same struct type can share the descriptor.
-	fields := []*ir.Field{
-		ir.NewField(base.Pos, Lookup(".F"), nil, types.Types[types.TUINTPTR]),
+	fields := []*types.Field{
+		types.NewField(base.Pos, Lookup(".F"), types.Types[types.TUINTPTR]),
 	}
 	for _, v := range clo.Func.ClosureVars {
 		typ := v.Type()
 		if !v.Byval() {
 			typ = types.NewPtr(typ)
 		}
-		fields = append(fields, ir.NewField(base.Pos, v.Sym(), nil, typ))
+		fields = append(fields, types.NewField(base.Pos, v.Sym(), typ))
 	}
-	typ := NewStructType(fields)
+	typ := types.NewStruct(types.NoPkg, fields)
 	typ.SetNoalg(true)
 	return typ
 }
@@ -92,9 +92,9 @@ func ClosureType(clo *ir.ClosureExpr) *types.Type {
 // needed in the closure for n (n must be a OCALLPART node).
 // The address of a variable of the returned type can be cast to a func.
 func PartialCallType(n *ir.CallPartExpr) *types.Type {
-	t := NewStructType([]*ir.Field{
-		ir.NewField(base.Pos, Lookup("F"), nil, types.Types[types.TUINTPTR]),
-		ir.NewField(base.Pos, Lookup("R"), nil, n.X.Type()),
+	t := types.NewStruct(types.NoPkg, []*types.Field{
+		types.NewField(base.Pos, Lookup("F"), types.Types[types.TUINTPTR]),
+		types.NewField(base.Pos, Lookup("R"), n.X.Type()),
 	})
 	t.SetNoalg(true)
 	return t