fix(gnovm): update ValuePath depth access to use method calls

gnovm/pkg/gnolang/nodes.go

@@ -1808,9 +1808,9 @@ func (sb *StaticBlock) GetBlockNodeForPath(store Store, path ValuePath) BlockNod
 		panic("expected block type value path but got " + path.Type.String())
 	}
 
-	// NOTE: path.Depth == 1 means it's in bn.
+	// NOTE: path.Depth() == 1 means it's in bn.
 	bn := sb.GetSource(store)
-	for i := 1; i < int(path.Depth); i++ {
+	for i := 1; i < int(path.Depth()); i++ {
 		bn = bn.GetParentNode(store)
 	}
 
@@ -1903,7 +1903,7 @@ func (sb *StaticBlock) GetStaticTypeOf(store Store, n Name) Type {
 // Implements BlockNode.
 func (sb *StaticBlock) GetStaticTypeOfAt(store Store, path ValuePath) Type {
 	if debug {
-		if path.Depth == 0 {
+		if path.Depth() == 0 {
 			panic("should not happen")
 		}
 	}
@@ -2119,11 +2119,23 @@ func (x *PackageNode) SetBody(b Body) {
 // see tests/selector_test.go.
 type ValuePath struct {
 	Type  VPType // see VPType* consts.
-	Depth uint8  // see doc for ValuePath.
+	depth uint8  // see doc for ValuePath.
 	Index uint16 // index of value, field, or method.
 	Name  Name   // name of value, field, or method.
 }
 
+func (vp ValuePath) Depth() uint8 {
+	return vp.depth
+}
+
+func (vp *ValuePath) SetDepth(d uint8) {
+	if d > 127 {
+		panic("value path depth overflow")
+	}
+
+	vp.depth = d
+}
+
 type VPType uint8
 
 const (
@@ -2145,7 +2157,7 @@ const (
 func NewValuePath(t VPType, depth uint8, index uint16, n Name) ValuePath {
 	vp := ValuePath{
 		Type:  t,
-		Depth: depth,
+		depth: depth,
 		Index: index,
 		Name:  n,
 	}
@@ -2203,61 +2215,61 @@ func NewValuePathNative(n Name) ValuePath {
 
 func (vp ValuePath) Validate() {
 	// no ValuePath depths should exceed uint8/2
-	if vp.Depth > 127 {
+	if vp.Depth() > 127 {
 		panic("value path depth overflow")
 	}
 
 	switch vp.Type {
 	case VPUverse:
-		if vp.Depth != 0 {
+		if vp.Depth() != 0 {
 			panic("uverse value path must have depth 0")
 		}
 	case VPBlock:
 		// 0 ok ("_" blank)
 	case VPField:
-		if vp.Depth > 1 {
+		if vp.Depth() > 1 {
 			panic("field value path must have depth 0 or 1")
 		}
 	case VPValMethod:
-		if vp.Depth != 0 {
+		if vp.Depth() != 0 {
 			panic("method value path must have depth 0")
 		}
 	case VPPtrMethod:
-		if vp.Depth != 0 {
+		if vp.Depth() != 0 {
 			panic("ptr receiver method value path must have depth 0")
 		}
 	case VPInterface:
-		if vp.Depth != 0 {
+		if vp.Depth() != 0 {
 			panic("interface method value path must have depth 0")
 		}
 		if vp.Name == "" {
 			panic("interface value path must have name")
 		}
 	case VPSubrefField:
-		if vp.Depth > 3 {
+		if vp.Depth() > 3 {
 			panic("subref field value path must have depth 0, 1, 2, or 3")
 		}
 	case VPDerefField:
-		if vp.Depth > 3 {
+		if vp.Depth() > 3 {
 			panic("deref field value path must have depth 0, 1, 2, or 3")
 		}
 	case VPDerefValMethod:
-		if vp.Depth != 0 {
+		if vp.Depth() != 0 {
 			panic("(deref) method value path must have depth 0")
 		}
 	case VPDerefPtrMethod:
-		if vp.Depth != 0 {
+		if vp.Depth() != 0 {
 			panic("(deref) ptr receiver method value path must have depth 0")
 		}
 	case VPDerefInterface:
-		if vp.Depth != 0 {
+		if vp.Depth() != 0 {
 			panic("(deref) interface method value path must have depth 0")
 		}
 		if vp.Name == "" {
 			panic("(deref) interface value path must have name")
 		}
 	case VPNative:
-		if vp.Depth != 0 {
+		if vp.Depth() != 0 {
 			panic("native value path must have depth 0")
 		}
 		if vp.Name == "" {
@@ -2271,7 +2283,7 @@ func (vp ValuePath) Validate() {
 }
 
 func (vp ValuePath) IsBlockBlankPath() bool {
-	return vp.Type == VPBlock && vp.Depth == 0 && vp.Index == 0
+	return vp.Type == VPBlock && vp.Depth() == 0 && vp.Index == 0
 }
 
 func (vp ValuePath) IsDerefType() bool {

gnovm/pkg/gnolang/nodes_string.go

@@ -69,19 +69,19 @@ func (vp ValuePath) String() string {
 	case VPUverse:
 		return fmt.Sprintf("VPUverse(%d)", vp.Index)
 	case VPBlock:
-		return fmt.Sprintf("VPBlock(%d,%d)", vp.Depth, vp.Index)
+		return fmt.Sprintf("VPBlock(%d,%d)", vp.Depth(), vp.Index)
 	case VPField:
-		return fmt.Sprintf("VPField(%d,%d,%s)", vp.Depth, vp.Index, vp.Name)
+		return fmt.Sprintf("VPField(%d,%d,%s)", vp.Depth(), vp.Index, vp.Name)
 	case VPSubrefField:
-		return fmt.Sprintf("VPSubrefField(%d,%d,%s)", vp.Depth, vp.Index, vp.Name)
+		return fmt.Sprintf("VPSubrefField(%d,%d,%s)", vp.Depth(), vp.Index, vp.Name)
 	case VPValMethod:
 		return fmt.Sprintf("VPValMethod(%d,%s)", vp.Index, vp.Name)
 	case VPPtrMethod:
 		return fmt.Sprintf("VPPtrMethod(%d,%s)", vp.Index, vp.Name)
 	case VPInterface:
 		return fmt.Sprintf("VPInterface(%s)", vp.Name)
 	case VPDerefField:
-		return fmt.Sprintf("VPDerefField(%d,%d,%s)", vp.Depth, vp.Index, vp.Name)
+		return fmt.Sprintf("VPDerefField(%d,%d,%s)", vp.Depth(), vp.Index, vp.Name)
 	case VPDerefValMethod:
 		return fmt.Sprintf("VPDerefValMethod(%d,%s)", vp.Index, vp.Name)
 	case VPDerefPtrMethod:

gnovm/pkg/gnolang/op_eval.go

@@ -27,7 +27,7 @@ func (m *Machine) doOpEval() {
 	// TODO: understand this better.
 	if nx, ok := x.(*NameExpr); ok {
 		m.PopExpr()
-		if nx.Path.Depth == 0 {
+		if nx.Path.Depth() == 0 {
 			// Name is in uverse (global).
 			gv := Uverse().GetBlock(nil).GetPointerTo(nil, nx.Path)
 			m.PushValue(gv.Deref())

gnovm/pkg/gnolang/op_expressions.go

@@ -733,7 +733,7 @@ func (m *Machine) doOpStructLit() {
 			fnx := x.Elts[i].Key.(*NameExpr)
 			ftv := ftvs[i]
 			if debug {
-				if fnx.Path.Depth != 0 {
+				if fnx.Path.Depth() != 0 {
 					panic("unexpected struct composite lit key path generation value")
 				}
 				if !ftv.IsUndefined() && ftv.T.Kind() == InterfaceKind {

gnovm/pkg/gnolang/op_types.go

@@ -185,7 +185,7 @@ func (m *Machine) doOpStaticTypeOf() {
 	switch x := x.(type) {
 	case *NameExpr:
 		// NOTE: duplicated from doOpEval
-		if x.Path.Depth == 0 {
+		if x.Path.Depth() == 0 {
 			// Name is in uverse (global).
 			gv := Uverse().GetBlock(nil).GetPointerTo(nil, x.Path)
 			m.PushValue(asValue(gv.TV.T))
@@ -234,50 +234,50 @@ func (m *Machine) doOpStaticTypeOf() {
 		path := x.Path // mutable
 		switch path.Type {
 		case VPField:
-			switch path.Depth { // see tests/selector_test.go for cases.
+			switch path.Depth() { // see tests/selector_test.go for cases.
 			case 0:
 				dxt = xt
 			case 1:
 				dxt = baseOf(xt)
-				path.Depth = 0
+				path.SetDepth(0)
 			default:
 				panic("should not happen")
 			}
 		case VPSubrefField:
-			switch path.Depth {
+			switch path.Depth() {
 			case 0:
 				dxt = xt.Elem()
-				path.Depth = 0
+				path.SetDepth(0)
 			case 1:
 				dxt = xt.Elem()
-				path.Depth = 0
+				path.SetDepth(0)
 			case 2:
 				dxt = baseOf(xt.Elem())
-				path.Depth = 0
+				path.SetDepth(0)
 			case 3:
 				dxt = baseOf(xt.Elem())
-				path.Depth = 0
+				path.SetDepth(0)
 			default:
 				panic("should not happen")
 			}
 		case VPDerefField:
-			switch path.Depth {
+			switch path.Depth() {
 			case 0:
 				dxt = xt.Elem()
 				path.Type = VPField
-				path.Depth = 0
+				path.SetDepth(0)
 			case 1:
 				dxt = xt.Elem()
 				path.Type = VPField
-				path.Depth = 0
+				path.SetDepth(0)
 			case 2:
 				dxt = baseOf(xt.Elem())
 				path.Type = VPField
-				path.Depth = 0
+				path.SetDepth(0)
 			case 3:
 				dxt = baseOf(xt.Elem())
 				path.Type = VPField
-				path.Depth = 0
+				path.SetDepth(0)
 			default:
 				panic("should not happen")
 			}

gnovm/pkg/gnolang/preprocess.go

@@ -1026,7 +1026,7 @@ func preprocess1(store Store, ctx BlockNode, n Node) Node {
 						fillNameExprPath(last, n, false)
 					}
 					// If uverse, return a *ConstExpr.
-					if n.Path.Depth == 0 { // uverse
+					if n.Path.Depth() == 0 { // uverse
 						cx := evalConst(store, last, n)
 						// built-in functions must be called.
 						if !cx.IsUndefined() &&
@@ -2886,7 +2886,7 @@ func findLoopUses1(ctx BlockNode, bn BlockNode) {
 							idx := addHeapCapture(dbn, fle, n.Name)
 							// adjust NameExpr type.
 							n.Type = NameExprTypeHeapUse
-							n.Path.Depth = uint8(depth)
+							n.Path.SetDepth(uint8(depth))
 							n.Path.Index = idx
 						} else {
 							if ftype == TRANS_REF_X {
@@ -2982,7 +2982,7 @@ func addHeapCapture(dbn BlockNode, fle *FuncLitExpr, name Name) (idx uint16) {
 
 	// add name to fle.HeapCaptures.
 	vp := fle.GetPathForName(nil, name)
-	vp.Depth -= 1 // minus 1 for fle itself.
+	vp.SetDepth(vp.Depth() - 1) // minus 1 for fle itself.
 	ne := NameExpr{
 		Path: vp,
 		Name: name,
@@ -5066,7 +5066,7 @@ func fillNameExprPath(last BlockNode, nx *NameExpr, isDefineLHS bool) {
 					break
 				}
 			}
-			path.Depth += uint8(i)
+			path.SetDepth(path.Depth() + uint8(i))
 			path.Validate()
 			nx.Path = path
 			return

gnovm/pkg/gnolang/types.go

@@ -692,13 +692,13 @@ func (pt *PointerType) FindEmbeddedFieldType(callerPath string, n Name, m map[Ty
 				} else {
 					// Case 2: otherwise, is just a deref field.
 					trail[0].Type = VPDerefField
-					switch trail[0].Depth {
+					switch trail[0].Depth() {
 					case 0:
 						// *PointerType > *StructType.Field has depth 0.
 					case 1:
 						// *DeclaredType > *StructType.Field has depth 1 (& type VPField).
 						// *PointerType > *DeclaredType > *StructType.Field has depth 2.
-						trail[0].Depth = 2
+						trail[0].SetDepth(2)
 						/*
 							// If trail[-1].Type == VPPtrMethod, set VPDerefPtrMethod.
 							if len(trail) > 1 && trail[1].Type == VPPtrMethod {
@@ -804,7 +804,7 @@ func (st *StructType) GetPathForName(n Name) ValuePath {
 
 func (st *StructType) GetStaticTypeOfAt(path ValuePath) Type {
 	if debug {
-		if path.Depth != 0 {
+		if path.Depth() != 0 {
 			panic("expected path.Depth of 0")
 		}
 	}
@@ -1602,7 +1602,7 @@ func (dt *DeclaredType) GetPathForName(n Name) ValuePath {
 	}
 	// Otherwise it is underlying.
 	path := dt.Base.(ValuePather).GetPathForName(n)
-	path.Depth += 1
+	path.SetDepth(path.Depth() + 1)
 	return path
 }
 
@@ -1668,11 +1668,12 @@ func (dt *DeclaredType) FindEmbeddedFieldType(callerPath string, n Name, m map[T
 		return trail, hasPtr, rcvr, ft, false
 	case VPField, VPDerefField:
 		if debug {
-			if trail[0].Depth != 0 && trail[0].Depth != 2 {
+			if trail[0].Depth() != 0 && trail[0].Depth() != 2 {
 				panic("should not happen")
 			}
 		}
-		trail[0].Depth += 1
+
+		trail[0].SetDepth(trail[0].Depth() + 1)
 		return trail, hasPtr, rcvr, ft, false
 	default:
 		panic("should not happen")
@@ -1697,7 +1698,7 @@ func (dt *DeclaredType) GetValueAt(alloc *Allocator, store Store, path ValuePath
 		// should call *DT.FindEmbeddedFieldType(name) instead.
 		// tr, hp, rt, ft := dt.FindEmbeddedFieldType(n)
 	case VPValMethod, VPPtrMethod, VPField:
-		if path.Depth == 0 {
+		if path.Depth() == 0 {
 			mtv := dt.Methods[path.Index]
 			// Fill in *FV.Closure.
 			ft := mtv.T
@@ -1722,7 +1723,7 @@ func (dt *DeclaredType) GetStaticValueAt(path ValuePath) TypedValue {
 		// should call *DT.FindEmbeddedFieldType(name) instead.
 		// tr, hp, rt, ft := dt.FindEmbeddedFieldType(n)
 	case VPValMethod, VPPtrMethod, VPField:
-		if path.Depth == 0 {
+		if path.Depth() == 0 {
 			return dt.Methods[path.Index]
 		} else {
 			panic("DeclaredType.GetStaticValueAt() expects depth == 0")