cmd/compile: cleanup genwrapper slightly

ORETJMP doesn't need an ONAME if we just set the target method on Sym
instead of Left. Conveniently, this is where fmt.go was looking for it
anyway.

Change the iface parameter and global compiling_wrappers to bool.

Passes toolstash-check.

Change-Id: I5333f8bcb4e06bf8161808041125eb95c439aafe
Reviewed-on: https://go-review.googlesource.com/68252
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Robert Griesemer <gri@golang.org>

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

@@ -198,7 +198,7 @@ var compiling_runtime bool
 // Compiling the standard library
 var compiling_std bool
 
-var compiling_wrappers int
+var compiling_wrappers bool
 
 var use_writebarrier bool
 

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

@@ -438,18 +438,18 @@ func methods(t *types.Type) []*Sig {
 		if !sig.isym.Siggen() {
 			sig.isym.SetSiggen(true)
 			if !eqtype(this, it) || this.Width < int64(Widthptr) {
-				compiling_wrappers = 1
-				genwrapper(it, f, sig.isym, 1)
-				compiling_wrappers = 0
+				compiling_wrappers = true
+				genwrapper(it, f, sig.isym, true)
+				compiling_wrappers = false
 			}
 		}
 
 		if !sig.tsym.Siggen() {
 			sig.tsym.SetSiggen(true)
 			if !eqtype(this, t) {
-				compiling_wrappers = 1
-				genwrapper(t, f, sig.tsym, 0)
-				compiling_wrappers = 0
+				compiling_wrappers = true
+				genwrapper(t, f, sig.tsym, false)
+				compiling_wrappers = false
 			}
 		}
 	}
@@ -500,7 +500,7 @@ func imethods(t *types.Type) []*Sig {
 		isym := methodsym(method, t, false)
 		if !isym.Siggen() {
 			isym.SetSiggen(true)
-			genwrapper(t, f, isym, 0)
+			genwrapper(t, f, isym, false)
 		}
 	}
 

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

@@ -780,7 +780,7 @@ func (s *state) stmt(n *Node) {
 		s.stmtList(n.List)
 		b := s.exit()
 		b.Kind = ssa.BlockRetJmp // override BlockRet
-		b.Aux = n.Left.Sym.Linksym()
+		b.Aux = n.Sym.Linksym()
 
 	case OCONTINUE, OBREAK:
 		var to *ssa.Block

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

@@ -1671,7 +1671,7 @@ func structargs(tl *types.Type, mustname bool) []*Node {
 //	rcvr - U
 //	method - M func (t T)(), a TFIELD type struct
 //	newnam - the eventual mangled name of this function
-func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym, iface int) {
+func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym, iface bool) {
 	if false && Debug['r'] != 0 {
 		fmt.Printf("genwrapper rcvrtype=%v method=%v newnam=%v\n", rcvr, method, newnam)
 	}
@@ -1688,7 +1688,7 @@ func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym, iface
 
 	t := nod(OTFUNC, nil, nil)
 	l := []*Node{this}
-	if iface != 0 && rcvr.Width < int64(Widthptr) {
+	if iface && rcvr.Width < int64(Widthptr) {
 		// Building method for interface table and receiver
 		// is smaller than the single pointer-sized word
 		// that the interface call will pass in.
@@ -1746,9 +1746,7 @@ func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym, iface
 		as := nod(OAS, this.Left, nod(OCONVNOP, dot, nil))
 		as.Right.Type = rcvr
 		fn.Nbody.Append(as)
-		n := nod(ORETJMP, nil, nil)
-		n.Left = newname(methodsym(method.Sym, methodrcvr, false))
-		fn.Nbody.Append(n)
+		fn.Nbody.Append(nodSym(ORETJMP, nil, methodsym(method.Sym, methodrcvr, false)))
 		// When tail-calling, we can't use a frame pointer.
 		fn.Func.SetNoFramePointer(true)
 	} else {

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

@@ -266,7 +266,7 @@ func indexlit(n *Node) *Node {
 // 	n.Left = typecheck1(n.Left, top)
 func typecheck1(n *Node, top int) *Node {
 	switch n.Op {
-	case OXDOT, ODOT, ODOTPTR, ODOTMETH, ODOTINTER:
+	case OXDOT, ODOT, ODOTPTR, ODOTMETH, ODOTINTER, ORETJMP:
 		// n.Sym is a field/method name, not a variable.
 	default:
 		if n.Sym != nil {
@@ -2143,7 +2143,7 @@ func typecheck1(n *Node, top int) *Node {
 		}
 	}
 
-	if safemode && !inimport && compiling_wrappers == 0 && t != nil && t.Etype == TUNSAFEPTR {
+	if safemode && !inimport && !compiling_wrappers && t != nil && t.Etype == TUNSAFEPTR {
 		yyerror("cannot use unsafe.Pointer")
 	}