cmd/compile: add Type.ChanDir

Generated with eg.

Passes toolstash -cmp.

Change-Id: I3af35191e73a558080f777a4eed93bcec7dfe1f5
Reviewed-on: https://go-review.googlesource.com/21469
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

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

@@ -547,7 +547,7 @@ func (p *exporter) typ(t *Type) {
 
 	case TCHAN:
 		p.tag(chanTag)
-		p.int(int(t.Chan))
+		p.int(int(t.ChanDir()))
 		p.typ(t.Elem())
 
 	default:

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

@@ -596,7 +596,7 @@ func typefmt(t *Type, flag FmtFlag) string {
 		return "[]" + t.Elem().String()
 
 	case TCHAN:
-		switch t.Chan {
+		switch t.ChanDir() {
 		case Crecv:
 			return "<-chan " + t.Elem().String()
 
@@ -604,7 +604,7 @@ func typefmt(t *Type, flag FmtFlag) string {
 			return "chan<- " + t.Elem().String()
 		}
 
-		if t.Elem() != nil && t.Elem().IsChan() && t.Elem().Sym == nil && t.Elem().Chan == Crecv {
+		if t.Elem() != nil && t.Elem().IsChan() && t.Elem().Sym == nil && t.Elem().ChanDir() == Crecv {
 			return "chan (" + t.Elem().String() + ")"
 		}
 		return "chan " + t.Elem().String()
@@ -1102,7 +1102,7 @@ func exprfmt(n *Node, prec int) string {
 		if n.Type != nil && n.Type.Etype != TIDEAL && n.Type.Etype != TNIL && n.Type != idealbool && n.Type != idealstring {
 			// Need parens when type begins with what might
 			// be misinterpreted as a unary operator: * or <-.
-			if n.Type.IsPtr() || (n.Type.IsChan() && n.Type.Chan == Crecv) {
+			if n.Type.IsPtr() || (n.Type.IsChan() && n.Type.ChanDir() == Crecv) {
 				return fmt.Sprintf("(%v)(%v)", n.Type, Vconv(n.Val(), 0))
 			} else {
 				return fmt.Sprintf("%v(%v)", n.Type, Vconv(n.Val(), 0))

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

@@ -58,7 +58,7 @@ func typecheckrange(n *Node) {
 		t2 = t.Val()
 
 	case TCHAN:
-		if t.Chan&Crecv == 0 {
+		if t.ChanDir()&Crecv == 0 {
 			Yyerror("invalid operation: range %v (receive from send-only type %v)", n.Right, n.Right.Type)
 			goto out
 		}

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

@@ -1143,7 +1143,7 @@ ok:
 
 		ot = dcommontype(s, ot, t)
 		ot = dsymptr(s, ot, s1, 0)
-		ot = duintptr(s, ot, uint64(t.Chan))
+		ot = duintptr(s, ot, uint64(t.ChanDir()))
 		ot = dextratype(s, ot, t, 0)
 
 	case TFUNC:

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

@@ -721,7 +721,7 @@ func eqtype1(t1, t2 *Type, assumedEqual map[typePair]struct{}) bool {
 		}
 
 	case TCHAN:
-		if t1.Chan != t2.Chan {
+		if t1.ChanDir() != t2.ChanDir() {
 			return false
 		}
 
@@ -844,7 +844,7 @@ func assignop(src *Type, dst *Type, why *string) Op {
 	// 4. src is a bidirectional channel value, dst is a channel type,
 	// src and dst have identical element types, and
 	// either src or dst is not a named type.
-	if src.IsChan() && src.Chan == Cboth && dst.IsChan() {
+	if src.IsChan() && src.ChanDir() == Cboth && dst.IsChan() {
 		if Eqtype(src.Elem(), dst.Elem()) && (src.Sym == nil || dst.Sym == nil) {
 			return OCONVNOP
 		}

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

@@ -817,8 +817,8 @@ func (t *Type) cmp(x *Type) ssa.Cmp {
 		}
 
 	case TCHAN:
-		if t.Chan != x.Chan {
-			return cmpForNe(t.Chan < x.Chan)
+		if t.ChanDir() != x.ChanDir() {
+			return cmpForNe(t.ChanDir() < x.ChanDir())
 		}
 
 	default:
@@ -955,6 +955,13 @@ func (t *Type) SetNumElem(n int64) {
 	t.Bound = n
 }
 
+// ChanDir returns the direction of a channel type t.
+// The direction will be one of Crecv, Csend, or Cboth.
+func (t *Type) ChanDir() uint8 {
+	t.wantEtype(TCHAN)
+	return t.Chan
+}
+
 func (t *Type) IsMemory() bool { return false }
 func (t *Type) IsFlags() bool  { return false }
 func (t *Type) IsVoid() bool   { return false }

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

@@ -1048,7 +1048,7 @@ OpSwitch:
 			return n
 		}
 
-		if t.Chan&Crecv == 0 {
+		if t.ChanDir()&Crecv == 0 {
 			Yyerror("invalid operation: %v (receive from send-only type %v)", n, t)
 			n.Type = nil
 			return n
@@ -1075,7 +1075,7 @@ OpSwitch:
 			return n
 		}
 
-		if t.Chan&Csend == 0 {
+		if t.ChanDir()&Csend == 0 {
 			Yyerror("invalid operation: %v (send to receive-only type %v)", n, t)
 			n.Type = nil
 			return n
@@ -1528,7 +1528,7 @@ OpSwitch:
 			return n
 		}
 
-		if t.Chan&Csend == 0 {
+		if t.ChanDir()&Csend == 0 {
 			Yyerror("invalid operation: %v (cannot close receive-only channel)", n)
 			n.Type = nil
 			return n