cmd/compile: remove syslook's copy parameter

Instead make substArgTypes responsible for cloning the function
definition Node and the function signature Type tree.

Passes toolstash -cmp.

Change-Id: I9ec84c90a7ae83d164d3f578e84a91cf1490d8ab
Reviewed-on: https://go-review.googlesource.com/20239
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/compile/internal/gc/alg.go

@@ -570,16 +570,16 @@ func eqmemfunc(size int64, type_ *Type, needsize *int) *Node {
 
 	switch size {
 	default:
-		fn = syslook("memequal", 1)
+		fn = syslook("memequal")
 		*needsize = 1
 
 	case 1, 2, 4, 8, 16:
 		buf := fmt.Sprintf("memequal%d", int(size)*8)
-		fn = syslook(buf, 1)
+		fn = syslook(buf)
 		*needsize = 0
 	}
 
-	substArgTypes(fn, type_, type_)
+	substArgTypes(&fn, type_, type_)
 	return fn
 }
 

src/cmd/compile/internal/gc/cgen.go

@@ -801,7 +801,7 @@ func cgen_wbptr(n, res *Node) {
 		Cgenr(n, &src, nil)
 	}
 
-	wbVar := syslook("writeBarrier", 0)
+	wbVar := syslook("writeBarrier")
 	wbEnabled := Nod(ODOT, wbVar, newname(wbVar.Type.Type.Sym))
 	wbEnabled = typecheck(&wbEnabled, Erv)
 	pbr := Thearch.Ginscmp(ONE, Types[TUINT8], wbEnabled, Nodintconst(0), -1)
@@ -2874,8 +2874,8 @@ func cgen_append(n, res *Node) {
 	arg.Xoffset += int64(Widthptr)
 	Regfree(&rlen)
 
-	fn := syslook("growslice", 1)
-	substArgTypes(fn, res.Type.Type, res.Type.Type)
+	fn := syslook("growslice")
+	substArgTypes(&fn, res.Type.Type, res.Type.Type)
 	Ginscall(fn, 0)
 
 	if Widthptr == 4 && Widthreg == 8 {

src/cmd/compile/internal/gc/gen.go

@@ -434,7 +434,7 @@ func cgen_dottype(n *Node, res, resok *Node, wb bool) {
 		q := Gbranch(obj.AJMP, nil, 0)
 		Patch(p, Pc)
 		Regrealloc(&r2) // reclaim from above, for this failure path
-		fn := syslook("panicdottype", 0)
+		fn := syslook("panicdottype")
 		dowidth(fn.Type)
 		call := Nod(OCALLFUNC, fn, nil)
 		r1.Type = byteptr
@@ -522,7 +522,7 @@ func Cgen_As2dottype(n, res, resok *Node) {
 	q := Gbranch(obj.AJMP, nil, 0)
 	Patch(p, Pc)
 
-	fn := syslook("panicdottype", 0)
+	fn := syslook("panicdottype")
 	dowidth(fn.Type)
 	call := Nod(OCALLFUNC, fn, nil)
 	setNodeSeq(&call.List, list(list(list1(&r1), &r2), typename(n.Left.Type)))

src/cmd/compile/internal/gc/init.go

@@ -132,7 +132,7 @@ func fninit(n *NodeList) {
 	b.Likely = 1
 	r = append(r, b)
 	// (4a)
-	b.Nbody.Set([]*Node{Nod(OCALL, syslook("throwinit", 0), nil)})
+	b.Nbody.Set([]*Node{Nod(OCALL, syslook("throwinit"), nil)})
 
 	// (6)
 	a = Nod(OAS, gatevar, Nodintconst(1))

src/cmd/compile/internal/gc/range.go

@@ -230,14 +230,14 @@ func walkrange(n *Node) {
 		keyname := newname(th.Type.Sym)      // depends on layout of iterator struct.  See reflect.go:hiter
 		valname := newname(th.Type.Down.Sym) // ditto
 
-		fn := syslook("mapiterinit", 1)
+		fn := syslook("mapiterinit")
 
-		substArgTypes(fn, t.Down, t.Type, th)
+		substArgTypes(&fn, t.Down, t.Type, th)
 		init = list(init, mkcall1(fn, nil, nil, typename(t), ha, Nod(OADDR, hit, nil)))
 		n.Left = Nod(ONE, Nod(ODOT, hit, keyname), nodnil())
 
-		fn = syslook("mapiternext", 1)
-		substArgTypes(fn, th)
+		fn = syslook("mapiternext")
+		substArgTypes(&fn, th)
 		n.Right = mkcall1(fn, nil, nil, Nod(OADDR, hit, nil))
 
 		key := Nod(ODOT, hit, keyname)
@@ -297,7 +297,7 @@ func walkrange(n *Node) {
 			hv2 = temp(runetype)
 			a = Nod(OAS2, nil, nil)
 			a.List = list(list1(hv1), hv2)
-			fn := syslook("stringiter2", 0)
+			fn := syslook("stringiter2")
 			a.Rlist = list1(mkcall1(fn, getoutargx(fn.Type), nil, ha, hv1))
 		}
 

src/cmd/compile/internal/gc/ssa.go

@@ -2778,7 +2778,7 @@ func (s *state) insertWBmove(t *Type, left, right *ssa.Value, line int32) {
 	bElse := s.f.NewBlock(ssa.BlockPlain)
 	bEnd := s.f.NewBlock(ssa.BlockPlain)
 
-	aux := &ssa.ExternSymbol{Types[TBOOL], syslook("writeBarrier", 0).Sym}
+	aux := &ssa.ExternSymbol{Types[TBOOL], syslook("writeBarrier").Sym}
 	flagaddr := s.newValue1A(ssa.OpAddr, Ptrto(Types[TUINT32]), aux, s.sb)
 	// TODO: select the .enabled field. It is currently first, so not needed for now.
 	// Load word, test byte, avoiding partial register write from load byte.
@@ -2823,7 +2823,7 @@ func (s *state) insertWBstore(t *Type, left, right *ssa.Value, line int32) {
 	bElse := s.f.NewBlock(ssa.BlockPlain)
 	bEnd := s.f.NewBlock(ssa.BlockPlain)
 
-	aux := &ssa.ExternSymbol{Types[TBOOL], syslook("writeBarrier", 0).Sym}
+	aux := &ssa.ExternSymbol{Types[TBOOL], syslook("writeBarrier").Sym}
 	flagaddr := s.newValue1A(ssa.OpAddr, Ptrto(Types[TUINT32]), aux, s.sb)
 	// TODO: select the .enabled field. It is currently first, so not needed for now.
 	// Load word, test byte, avoiding partial register write from load byte.

src/cmd/compile/internal/gc/subr.go

@@ -1112,10 +1112,15 @@ func assignconvfn(n *Node, t *Type, context func() string) *Node {
 // substArgTypes substitutes the given list of types for
 // successive occurrences of the "any" placeholder in the
 // type syntax expression n.Type.
-func substArgTypes(n *Node, types ...*Type) {
+func substArgTypes(np **Node, types ...*Type) {
+	n := Nod(0, nil, nil)
+	*n = **np
+	*np = n
+
 	for _, t := range types {
 		dowidth(t)
 	}
+	n.Type = deep(n.Type)
 	substAny(&n.Type, &types)
 	if len(types) > 0 {
 		Fatalf("substArgTypes: too many argument types")
@@ -1259,21 +1264,12 @@ func deep(t *Type) *Type {
 	return nt
 }
 
-func syslook(name string, copy int) *Node {
+func syslook(name string) *Node {
 	s := Pkglookup(name, Runtimepkg)
 	if s == nil || s.Def == nil {
 		Fatalf("syslook: can't find runtime.%s", name)
 	}
-
-	if copy == 0 {
-		return s.Def
-	}
-
-	n := Nod(0, nil, nil)
-	*n = *s.Def
-	n.Type = deep(s.Def.Type)
-
-	return n
+	return s.Def
 }
 
 // compute a hash value for type t.
@@ -2149,7 +2145,7 @@ func genwrapper(rcvr *Type, method *Type, newnam *Sym, iface int) {
 		l = list(l, nodlit(v))
 		v.U = method.Sym.Name
 		l = list(l, nodlit(v)) // method name
-		call := Nod(OCALL, syslook("panicwrap", 0), nil)
+		call := Nod(OCALL, syslook("panicwrap"), nil)
 		call.List = l
 		n.Nbody.Set([]*Node{call})
 		fn.Nbody.Append(n)