cmd/compile: add OSLICELIT

Does not pass toolstash -cmp due to changed export data,
but the cmd/go binary (which doesn't contain export data)
is bit-for-bit identical.

Change-Id: I6b12f9de18cf7da528e9207dccbf8f08c969f142
Reviewed-on: https://go-review.googlesource.com/26753
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

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

@@ -1258,7 +1258,7 @@ func (p *exporter) expr(n *Node) {
 		p.typ(n.Type)
 		p.elemList(n.List) // special handling of field names
 
-	case OARRAYLIT, OMAPLIT:
+	case OARRAYLIT, OSLICELIT, OMAPLIT:
 		p.op(OCOMPLIT)
 		p.typ(n.Type)
 		p.exprList(n.List)

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

@@ -897,7 +897,7 @@ func (p *importer) node() *Node {
 		n.List.Set(p.elemList()) // special handling of field names
 		return n
 
-	// case OARRAYLIT, OMAPLIT:
+	// case OARRAYLIT, OSLICELIT, OMAPLIT:
 	// 	unreachable - mapped to case OCOMPLIT below by exporter
 
 	case OCOMPLIT:

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

@@ -863,15 +863,17 @@ func esc(e *EscState, n *Node, up *Node) {
 		escassignNilWhy(e, n, n.Left, "interface-converted")
 
 	case OARRAYLIT:
-		why := "array literal element"
-		if n.Type.IsSlice() {
-			// Slice itself is not leaked until proven otherwise
-			e.track(n)
-			why = "slice literal element"
+		// Link values to array
+		for _, n5 := range n.List.Slice() {
+			escassign(e, n, n5.Right, e.stepAssign(nil, n, n5.Right, "array literal element"))
 		}
-		// Link values to array/slice
+
+	case OSLICELIT:
+		// Slice is not leaked until proven otherwise
+		e.track(n)
+		// Link values to slice
 		for _, n5 := range n.List.Slice() {
-			escassign(e, n, n5.Right, e.stepAssign(nil, n, n5.Right, why))
+			escassign(e, n, n5.Right, e.stepAssign(nil, n, n5.Right, "slice literal element"))
 		}
 
 		// Link values to struct.
@@ -1015,6 +1017,7 @@ func escassign(e *EscState, dst, src *Node, step *EscStep) {
 		Fatalf("escassign: unexpected dst")
 
 	case OARRAYLIT,
+		OSLICELIT,
 		OCLOSURE,
 		OCONV,
 		OCONVIFACE,
@@ -1071,6 +1074,7 @@ func escassign(e *EscState, dst, src *Node, step *EscStep) {
 		ODDDARG,
 		OPTRLIT,
 		OARRAYLIT,
+		OSLICELIT,
 		OMAPLIT,
 		OSTRUCTLIT,
 		OMAKECHAN,
@@ -1587,6 +1591,7 @@ func esccall(e *EscState, n *Node, up *Node) {
 					OCLOSURE,
 					ODDDARG,
 					OARRAYLIT,
+					OSLICELIT,
 					OPTRLIT,
 					OSTRUCTLIT:
 					a.Noescape = true
@@ -1881,10 +1886,7 @@ func escwalkBody(e *EscState, level Level, dst *Node, src *Node, step *EscStep,
 		// similar to a slice arraylit and its args.
 		level = level.dec()
 
-	case OARRAYLIT:
-		if src.Type.IsArray() {
-			break
-		}
+	case OSLICELIT:
 		for _, n1 := range src.List.Slice() {
 			escwalk(e, level.dec(), dst, n1.Right, e.stepWalk(dst, n1.Right, "slice-literal-element", step))
 		}

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

@@ -182,6 +182,7 @@ func reexportdep(n *Node) {
 		ODOTTYPE2,
 		OSTRUCTLIT,
 		OARRAYLIT,
+		OSLICELIT,
 		OPTRLIT,
 		OMAKEMAP,
 		OMAKESLICE,

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

@@ -931,6 +931,7 @@ var opprec = []int{
 	OAPPEND:       8,
 	OARRAYBYTESTR: 8,
 	OARRAYLIT:     8,
+	OSLICELIT:     8,
 	OARRAYRUNESTR: 8,
 	OCALLFUNC:     8,
 	OCALLINTER:    8,
@@ -1172,7 +1173,7 @@ func (p *printer) exprfmt(n *Node, prec int) *printer {
 	case OPTRLIT:
 		return p.f("&%v", n.Left)
 
-	case OSTRUCTLIT, OARRAYLIT, OMAPLIT:
+	case OSTRUCTLIT, OARRAYLIT, OSLICELIT, OMAPLIT:
 		if fmtmode == FErr {
 			return p.f("%v literal", n.Type)
 		}

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

@@ -48,6 +48,7 @@ var opnames = []string{
 	OMAPLIT:          "MAPLIT",
 	OSTRUCTLIT:       "STRUCTLIT",
 	OARRAYLIT:        "ARRAYLIT",
+	OSLICELIT:        "SLICELIT",
 	OPTRLIT:          "PTRLIT",
 	OCONV:            "CONV",
 	OCONVIFACE:       "CONVIFACE",

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

@@ -1160,7 +1160,7 @@ func orderexpr(n *Node, order *Order, lhs *Node) *Node {
 			prealloc[n] = ordertemp(Types[TUINT8], order, false) // walk will fill in correct type
 		}
 
-	case OARRAYLIT, OCALLPART:
+	case OARRAYLIT, OSLICELIT, OCALLPART:
 		n.Left = orderexpr(n.Left, order, nil)
 		n.Right = orderexpr(n.Right, order, nil)
 		orderexprlist(n.List, order)

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

@@ -368,6 +368,7 @@ func instrumentnode(np **Node, init *Nodes, wr int, skip int) {
 		OCLOSURE,  // lowered to PTRLIT
 		ORANGE,    // lowered to ordinary for loop
 		OARRAYLIT, // lowered to assignments
+		OSLICELIT,
 		OMAPLIT,
 		OSTRUCTLIT,
 		OAS2,

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

@@ -316,33 +316,26 @@ func staticcopy(l *Node, r *Node, out *[]*Node) bool {
 
 	case OPTRLIT:
 		switch r.Left.Op {
-		//dump("not static addr", r);
-		default:
-			break
-
+		case OARRAYLIT, OSLICELIT, OSTRUCTLIT, OMAPLIT:
 			// copy pointer
-		case OARRAYLIT, OSTRUCTLIT, OMAPLIT:
 			gdata(l, Nod(OADDR, inittemps[r], nil), int(l.Type.Width))
-
 			return true
 		}
 
-	case OARRAYLIT:
-		if r.Type.IsSlice() {
-			// copy slice
-			a := inittemps[r]
+	case OSLICELIT:
+		// copy slice
+		a := inittemps[r]
 
-			n := *l
-			n.Xoffset = l.Xoffset + int64(Array_array)
-			gdata(&n, Nod(OADDR, a, nil), Widthptr)
-			n.Xoffset = l.Xoffset + int64(Array_nel)
-			gdata(&n, r.Right, Widthint)
-			n.Xoffset = l.Xoffset + int64(Array_cap)
-			gdata(&n, r.Right, Widthint)
-			return true
-		}
-		fallthrough
-	case OSTRUCTLIT:
+		n := *l
+		n.Xoffset = l.Xoffset + int64(Array_array)
+		gdata(&n, Nod(OADDR, a, nil), Widthptr)
+		n.Xoffset = l.Xoffset + int64(Array_nel)
+		gdata(&n, r.Right, Widthint)
+		n.Xoffset = l.Xoffset + int64(Array_cap)
+		gdata(&n, r.Right, Widthint)
+		return true
+
+	case OARRAYLIT, OSTRUCTLIT:
 		p := initplans[r]
 
 		n := *l
@@ -405,7 +398,7 @@ func staticassign(l *Node, r *Node, out *[]*Node) bool {
 
 	case OPTRLIT:
 		switch r.Left.Op {
-		case OARRAYLIT, OMAPLIT, OSTRUCTLIT:
+		case OARRAYLIT, OSLICELIT, OMAPLIT, OSTRUCTLIT:
 			// Init pointer.
 			a := staticname(r.Left.Type, 1)
 
@@ -427,28 +420,26 @@ func staticassign(l *Node, r *Node, out *[]*Node) bool {
 			return true
 		}
 
-	case OARRAYLIT:
+	case OSLICELIT:
 		initplan(r)
-		if r.Type.IsSlice() {
-			// Init slice.
-			bound := r.Right.Int64()
-			ta := typArray(r.Type.Elem(), bound)
-			a := staticname(ta, 1)
-			inittemps[r] = a
-			n := *l
-			n.Xoffset = l.Xoffset + int64(Array_array)
-			gdata(&n, Nod(OADDR, a, nil), Widthptr)
-			n.Xoffset = l.Xoffset + int64(Array_nel)
-			gdata(&n, r.Right, Widthint)
-			n.Xoffset = l.Xoffset + int64(Array_cap)
-			gdata(&n, r.Right, Widthint)
-
-			// Fall through to init underlying array.
-			l = a
-		}
+		// Init slice.
+		bound := r.Right.Int64()
+		ta := typArray(r.Type.Elem(), bound)
+		a := staticname(ta, 1)
+		inittemps[r] = a
+		n := *l
+		n.Xoffset = l.Xoffset + int64(Array_array)
+		gdata(&n, Nod(OADDR, a, nil), Widthptr)
+		n.Xoffset = l.Xoffset + int64(Array_nel)
+		gdata(&n, r.Right, Widthint)
+		n.Xoffset = l.Xoffset + int64(Array_cap)
+		gdata(&n, r.Right, Widthint)
+
+		// Fall through to init underlying array.
+		l = a
 		fallthrough
 
-	case OSTRUCTLIT:
+	case OARRAYLIT, OSTRUCTLIT:
 		initplan(r)
 
 		p := initplans[r]
@@ -543,12 +534,12 @@ func getdyn(n *Node, top bool) initGenType {
 		}
 		return initDynamic
 
-	case OARRAYLIT:
-		if !top && n.Type.IsSlice() {
+	case OSLICELIT:
+		if !top {
 			return initDynamic
 		}
 
-	case OSTRUCTLIT:
+	case OARRAYLIT, OSTRUCTLIT:
 	}
 
 	var mode initGenType
@@ -565,30 +556,27 @@ func getdyn(n *Node, top bool) initGenType {
 // isStaticCompositeLiteral reports whether n is a compile-time constant.
 func isStaticCompositeLiteral(n *Node) bool {
 	switch n.Op {
-	case OARRAYLIT:
-		if n.Type.IsSlice() {
-			return false
+	case OSLICELIT:
+		return false
+	case OARRAYLIT, OSTRUCTLIT:
+		for _, r := range n.List.Slice() {
+			if r.Op != OKEY {
+				Fatalf("isStaticCompositeLiteral: rhs not OKEY: %v", r)
+			}
+			index := r.Left
+			if n.Op == OARRAYLIT && index.Op != OLITERAL {
+				return false
+			}
+			value := r.Right
+			if !isStaticCompositeLiteral(value) {
+				return false
+			}
 		}
-	case OSTRUCTLIT:
+		return true
 	case OLITERAL:
 		return true
-	default:
-		return false
 	}
-	for _, r := range n.List.Slice() {
-		if r.Op != OKEY {
-			Fatalf("isStaticCompositeLiteral: rhs not OKEY: %v", r)
-		}
-		index := r.Left
-		if n.Op == OARRAYLIT && index.Op != OLITERAL {
-			return false
-		}
-		value := r.Right
-		if !isStaticCompositeLiteral(value) {
-			return false
-		}
-	}
-	return true
+	return false
 }
 
 func structlit(ctxt int, pass int, n *Node, var_ *Node, init *Nodes) {
@@ -600,20 +588,19 @@ func structlit(ctxt int, pass int, n *Node, var_ *Node, init *Nodes) {
 		value := r.Right
 
 		switch value.Op {
-		case OARRAYLIT:
-			if value.Type.IsSlice() {
-				if pass == 1 && ctxt != 0 {
-					a := NodSym(ODOT, var_, index.Sym)
-					slicelit(ctxt, value, a, init)
-				} else if pass == 2 && ctxt == 0 {
-					a := NodSym(ODOT, var_, index.Sym)
-					slicelit(ctxt, value, a, init)
-				} else if pass == 3 {
-					break
-				}
-				continue
+		case OSLICELIT:
+			if pass == 1 && ctxt != 0 {
+				a := NodSym(ODOT, var_, index.Sym)
+				slicelit(ctxt, value, a, init)
+			} else if pass == 2 && ctxt == 0 {
+				a := NodSym(ODOT, var_, index.Sym)
+				slicelit(ctxt, value, a, init)
+			} else if pass == 3 {
+				break
 			}
+			continue
 
+		case OARRAYLIT:
 			a := NodSym(ODOT, var_, index.Sym)
 			arraylit(ctxt, pass, value, a, init)
 			continue
@@ -662,20 +649,19 @@ func arraylit(ctxt int, pass int, n *Node, var_ *Node, init *Nodes) {
 		value := r.Right
 
 		switch value.Op {
-		case OARRAYLIT:
-			if value.Type.IsSlice() {
-				if pass == 1 && ctxt != 0 {
-					a := Nod(OINDEX, var_, index)
-					slicelit(ctxt, value, a, init)
-				} else if pass == 2 && ctxt == 0 {
-					a := Nod(OINDEX, var_, index)
-					slicelit(ctxt, value, a, init)
-				} else if pass == 3 {
-					break
-				}
-				continue
+		case OSLICELIT:
+			if pass == 1 && ctxt != 0 {
+				a := Nod(OINDEX, var_, index)
+				slicelit(ctxt, value, a, init)
+			} else if pass == 2 && ctxt == 0 {
+				a := Nod(OINDEX, var_, index)
+				slicelit(ctxt, value, a, init)
+			} else if pass == 3 {
+				break
 			}
+			continue
 
+		case OARRAYLIT:
 			a := Nod(OINDEX, var_, index)
 			arraylit(ctxt, pass, value, a, init)
 			continue
@@ -825,10 +811,10 @@ func slicelit(ctxt int, n *Node, var_ *Node, init *Nodes) {
 		// TODO need to check bounds?
 
 		switch value.Op {
+		case OSLICELIT:
+			break
+
 		case OARRAYLIT:
-			if value.Type.IsSlice() {
-				break
-			}
 			arraylit(ctxt, 2, value, a, init)
 			continue
 
@@ -1079,15 +1065,10 @@ func anylit(ctxt int, n *Node, var_ *Node, init *Nodes) {
 
 		structlit(ctxt, 3, n, var_, init)
 
-	case OARRAYLIT:
-		if t.IsSlice() {
-			slicelit(ctxt, n, var_, init)
-			break
-		}
-		if !t.IsArray() {
-			Fatalf("anylit: not array")
-		}
+	case OSLICELIT:
+		slicelit(ctxt, n, var_, init)
 
+	case OARRAYLIT:
 		if var_.isSimpleName() && n.List.Len() > 4 {
 			if ctxt == 0 {
 				// lay out static data
@@ -1162,7 +1143,7 @@ func oaslit(n *Node, init *Nodes) bool {
 		// not a special composit literal assignment
 		return false
 
-	case OSTRUCTLIT, OARRAYLIT, OMAPLIT:
+	case OSTRUCTLIT, OARRAYLIT, OSLICELIT, OMAPLIT:
 		if vmatch1(n.Left, n.Right) {
 			// not a special composit literal assignment
 			return false
@@ -1235,7 +1216,7 @@ func initplan(n *Node) {
 	default:
 		Fatalf("initplan")
 
-	case OARRAYLIT:
+	case OARRAYLIT, OSLICELIT:
 		for _, a := range n.List.Slice() {
 			if a.Op != OKEY || !Smallintconst(a.Left) {
 				Fatalf("initplan arraylit")
@@ -1304,12 +1285,7 @@ func iszero(n *Node) bool {
 			return u.Real.CmpFloat64(0) == 0 && u.Imag.CmpFloat64(0) == 0
 		}
 
-	case OARRAYLIT:
-		if n.Type.IsSlice() {
-			break
-		}
-		fallthrough
-	case OSTRUCTLIT:
+	case OARRAYLIT, OSTRUCTLIT:
 		for _, n1 := range n.List.Slice() {
 			if !iszero(n1.Right) {
 				return false
@@ -1322,7 +1298,7 @@ func iszero(n *Node) bool {
 }
 
 func isvaluelit(n *Node) bool {
-	return (n.Op == OARRAYLIT && n.Type.IsArray()) || n.Op == OSTRUCTLIT
+	return n.Op == OARRAYLIT || n.Op == OSTRUCTLIT
 }
 
 // gen_as_init attempts to emit static data for n and reports whether it succeeded.

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

@@ -702,7 +702,7 @@ func (s *state) stmt(n *Node) {
 		rhs := n.Right
 		if rhs != nil {
 			switch rhs.Op {
-			case OSTRUCTLIT, OARRAYLIT:
+			case OSTRUCTLIT, OARRAYLIT, OSLICELIT:
 				// All literals with nonzero fields have already been
 				// rewritten during walk. Any that remain are just T{}
 				// or equivalents. Use the zero value.

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

@@ -1397,7 +1397,7 @@ func safeexpr(n *Node, init *Nodes) *Node {
 		a = walkexpr(a, init)
 		return a
 
-	case OSTRUCTLIT, OARRAYLIT:
+	case OSTRUCTLIT, OARRAYLIT, OSLICELIT:
 		if isStaticCompositeLiteral(n) {
 			return n
 		}

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

@@ -362,7 +362,8 @@ const (
 	OCOMPLIT         // Right{List} (composite literal, not yet lowered to specific form)
 	OMAPLIT          // Type{List} (composite literal, Type is map)
 	OSTRUCTLIT       // Type{List} (composite literal, Type is struct)
-	OARRAYLIT        // Type{List} (composite literal, Type is array or slice)
+	OARRAYLIT        // Type{List} (composite literal, Type is array)
+	OSLICELIT        // Type{List} (composite literal, Type is slice)
 	OPTRLIT          // &Left (left is composite literal)
 	OCONV            // Type(Left) (type conversion)
 	OCONVIFACE       // Type(Left) (type conversion, to interface)

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

@@ -2941,8 +2941,10 @@ func typecheckcomplit(n *Node) *Node {
 		}
 		if t.IsSlice() {
 			n.Right = Nodintconst(length)
+			n.Op = OSLICELIT
+		} else {
+			n.Op = OARRAYLIT
 		}
-		n.Op = OARRAYLIT
 
 	case TMAP:
 		hash := make(map[uint32][]*Node)

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

@@ -1632,7 +1632,7 @@ opswitch:
 		r.Type = n.Type
 		n = r
 
-	case OARRAYLIT, OMAPLIT, OSTRUCTLIT, OPTRLIT:
+	case OARRAYLIT, OSLICELIT, OMAPLIT, OSTRUCTLIT, OPTRLIT:
 		if isStaticCompositeLiteral(n) {
 			// n can be directly represented in the read-only data section.
 			// Make direct reference to the static data. See issue 12841.
@@ -4051,6 +4051,7 @@ func candiscard(n *Node) bool {
 		OMAPLIT,
 		OSTRUCTLIT,
 		OARRAYLIT,
+		OSLICELIT,
 		OPTRLIT,
 		OCONV,
 		OCONVIFACE,