feat: null receipts

gen/builders/builder_message.go

@@ -103,27 +103,32 @@ func (b *MessageVectorBuilder) CommitApplies() {
 
 	for _, am := range b.Messages.All() {
 		// apply all messages that are pending application.
-		if am.Result == nil {
+		if !am.Applied {
 			b.StateTracker.ApplyMessage(am)
 		}
 
 		b.vector.ApplyMessages = append(b.vector.ApplyMessages, schema.Message{
 			Bytes: MustSerialize(am.Message),
 			Epoch: &am.Epoch,
 		})
-		b.vector.Post.Receipts = append(b.vector.Post.Receipts, &schema.Receipt{
-			ExitCode:    am.Result.ExitCode,
-			ReturnValue: am.Result.Return,
-			GasUsed:     am.Result.GasUsed,
-		})
+
+		// am.Result may still be nil if the message failed to be applied
+		if am.Result != nil {
+			b.vector.Post.Receipts = append(b.vector.Post.Receipts, &schema.Receipt{
+				ExitCode:    am.Result.ExitCode,
+				ReturnValue: am.Result.Return,
+				GasUsed:     am.Result.GasUsed,
+			})
+		} else {
+			b.vector.Post.Receipts = append(b.vector.Post.Receipts, nil)
+		}
 	}
 
 	// update the internal state.
 	b.PostRoot = b.StateTracker.CurrRoot
 	b.vector.Post.StateTree = &schema.StateTree{RootCID: b.PostRoot}
 	b.Stage = StageChecks
 	b.Assert.enterStage(StageChecks)
-
 }
 
 // Finish signals to the builder that the checks stage is complete and that the

gen/builders/messages.go

@@ -38,6 +38,10 @@ type ApplicableMessage struct {
 	Epoch   abi.ChainEpoch
 	Message *types.Message
 	Result  *vm.ApplyRet
+	// Applied is true if this message has already been applied. Note it's
+	// not safe to rely on non-nil Result as indication of application
+	// since applied messages may fail without a result.
+	Applied bool
 }
 
 func (m *Messages) Sugar() *sugarMsg {

gen/builders/predicates.go

@@ -48,12 +48,14 @@ func MessageReturns(expect cbg.CBORMarshaler) ApplyRetPredicate {
 	}
 }
 
-// PanickedRet represents a non-return value, a placeholder for when an actor panicked while applying a message.
-var PanickedRet = vm.ApplyRet{}
-
-// Panicked returns an ApplyRetPredicate that passes if the message response is the PanickedRet.
-func Panicked() ApplyRetPredicate {
-	return MessageReturns(&PanickedRet)
+// Nil returns an ApplyRetPredicate that passes if the message receipt is nil.
+func Nil() ApplyRetPredicate {
+	return func(ret *vm.ApplyRet) error {
+		if ret != nil {
+			return fmt.Errorf("message receipt was not nil: %+v", ret)
+		}
+		return nil
+	}
 }
 
 // BalanceUpdated returns a ActorPredicate that checks whether the balance

gen/builders/state_tracker.go

@@ -86,10 +86,16 @@ func (st *StateTracker) Flush() cid.Cid {
 // root, refreshes the state tree, and updates the underlying vector with the
 // message and its receipt.
 func (st *StateTracker) ApplyMessage(am *ApplicableMessage) {
+	var postRoot cid.Cid
 	var err error
-	am.Result, st.CurrRoot, err = st.Driver.ExecuteMessage(st.Stores.Blockstore, st.CurrRoot, am.Epoch, am.Message)
-	st.bc.Assert.NoError(err)
 
+	am.Applied = true
+	am.Result, postRoot, err = st.Driver.ExecuteMessage(st.Stores.Blockstore, st.CurrRoot, am.Epoch, am.Message)
+	if err != nil {
+		return
+	}
+
+	st.CurrRoot = postRoot
 	// replace the state tree.
 	st.StateTree, err = state.LoadStateTree(st.Stores.CBORStore, st.CurrRoot)
 	st.bc.Assert.NoError(err)

gen/suites/vm_violations/actor_abort.go

@@ -48,6 +48,6 @@ func actorPanic(msg string) func(*MessageVectorBuilder) {
 		)
 		v.CommitApplies()
 
-		v.Assert.LastMessageResultSatisfies(Panicked())
+		v.Assert.LastMessageResultSatisfies(Nil())
 	}
 }

schema.json

@@ -148,7 +148,14 @@
           "type": "array",
           "additionalItems": false,
           "items": {
-            "$ref": "#/definitions/receipt"
+            "oneOf": [
+              {
+                "type": "null"
+              },
+              {
+                "$ref": "#/definitions/receipt"
+              }
+            ]
           }
         },
         "receipts_roots": {