fix(gnovm): assign to deref pointers

gno.land/cmd/gnoland/testdata/issue-1326.txtar

@@ -0,0 +1,68 @@
+gnoland start
+
+# add contract
+gnokey maketx addpkg -pkgdir $WORK -pkgpath gno.land/r/demo/xx -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout OK!
+
+# execute New
+gnokey maketx call -pkgpath gno.land/r/demo/xx -func New -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout OK!
+
+# execute Delta for the first time
+gnokey maketx call -pkgpath gno.land/r/demo/xx -func Delta -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout '("1,1,1;" string)'
+stdout OK!
+
+gnokey maketx call -pkgpath gno.land/r/demo/xx -func Delta -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout '("1,1,1;2,2,2;" string)'
+stdout OK!
+
+-- realm.gno --
+package xx
+
+import (
+	"strconv"
+)
+
+type Move struct {
+	N1, N2, N3 byte
+}
+
+type S struct {
+	Moves []Move
+}
+
+func (s S) clone() S {
+	mv := s.Moves
+	return S{Moves: mv}
+}
+
+func (olds S) change() S {
+	s := olds.clone()
+
+	counter++
+	s.Moves = append([]Move{}, s.Moves...)
+	s.Moves = append(s.Moves, Move{counter, counter, counter})
+	return s
+}
+
+var el *S
+var counter byte
+
+func New() {
+	el = new(S)
+}
+
+func Delta() string {
+	n := el.change()
+	*el = n
+	return Values()
+}
+
+func Values() string {
+	s := ""
+	for _, val := range el.Moves {
+		s += strconv.Itoa(int(val.N1)) + "," + strconv.Itoa(int(val.N2)) + "," + strconv.Itoa(int(val.N3)) + ";"
+	}
+	return s
+}

gno.land/cmd/gnoland/testdata/star-assign.txtar

@@ -0,0 +1,61 @@
+loadpkg gno.land/p/demo/ufmt
+
+gnoland start
+
+# add contract
+gnokey maketx addpkg -pkgdir $WORK -pkgpath gno.land/r/demo/xx -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout OK!
+
+# execute New
+gnokey maketx call -pkgpath gno.land/r/demo/xx -func New -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout OK!
+
+gnokey maketx call -pkgpath gno.land/r/demo/xx -func Delta -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout OK!
+
+gnokey maketx call -pkgpath gno.land/r/demo/xx -func Values -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout '("1, hello, 100, 100, 8, 5, 8" string)'
+stdout OK!
+
+-- realm.gno --
+package xx
+
+import (
+	"gno.land/p/demo/ufmt"
+)
+
+type A struct {
+	nums []int
+}
+
+var (
+	intPtr *int
+	strPtr *string
+	aPtr *A
+	concretePtr *int
+	concreteValue int
+)
+
+func New() {
+	intPtr = new(int)
+	strPtr = new(string)
+	aPtr = &A{}
+	concretePtr = &concreteValue
+}
+
+func Delta() {
+	*intPtr++
+	*strPtr += "hello"
+	*aPtr = A{nums: []int{8, 5, 8}}
+	*concretePtr = 100
+}
+
+func Values() string {
+	var results string
+	results += ufmt.Sprintf("%d, %s, %d, %d", *intPtr, *strPtr, *concretePtr, concreteValue)
+	for _, n := range aPtr.nums {
+		results += ufmt.Sprintf(", %d", n)
+	}
+
+	return results
+}

gnovm/pkg/gnolang/machine.go

@@ -1904,7 +1904,14 @@
 		m.PushOp(OpEval)
 	case *StarExpr:
 		// evaluate X (a reference)
-		m.PushExpr(lx.X)
+
+		// The star expression is on the LHS, so evaluate the expression as
+		// a reference. This ensures the value that is pushed is a pointer to
+		// the pointer value represented by the lx.X expression. This will be
+		// helpful if the underlying pointer value dos not have a base;
+		// the base of the reference to the pointer value can be used instead,
+		// to properly mark the owning object as dirty.
+		m.PushExpr(&RefExpr{X: lx.X})
 		m.PushOp(OpEval)
 	case *CompositeLitExpr: // for *RefExpr e.g. &mystruct{}
 		// evaluate lx.
@@ -1931,6 +1938,20 @@
 		return xv.GetPointerTo(m.Alloc, m.Store, lx.Path)
 	case *StarExpr:
 		ptr := m.PopValue().V.(PointerValue)
+
+		// A star expression on the lefthand side of an assign statement is a bit of a
+		// special case and needs to be handled. The value pushed for it is always a
+		// reference to the actual value, so first dereference it by assigning it to
+		// valuePtr. If the pointer value has no base, use the base of its parent.
+		// Assigning a non-nil base ensures the parent gets marked as dirty and the
+		// updated value is persisted during realm finalization.
+		valuePtr := ptr.TV.V.(PointerValue)
+		if valuePtr.Base == nil {
+			valuePtr.Base = ptr.Base
+		}
+
+		ptr = valuePtr
+
 		return ptr
 	case *CompositeLitExpr: // for *RefExpr
 		tv := *m.PopValue()