Implement function to access state of system actor

Author: geoff-vball

chain/actors/builtin/system/actor.go.template

@@ -4,6 +4,7 @@ import (
 	"github.com/filecoin-project/lotus/chain/actors/adt"
 	"github.com/filecoin-project/lotus/chain/actors"
 	"github.com/filecoin-project/lotus/chain/types"
+	"github.com/ipfs/go-cid"
 
 	"golang.org/x/xerrors"
 
@@ -60,4 +61,5 @@ func MakeState(store adt.Store, av actors.Version) (State, error) {
 
 type State interface {
 	GetState() interface{}
+	GetBuiltinActors() cid.Cid
 }

chain/actors/builtin/system/state.go.template

@@ -36,4 +36,12 @@ type state{{.v}} struct {
 
 func (s *state{{.v}}) GetState() interface{} {
 	return &s.State
+}
+
+func (s *state{{.v}}) GetBuiltinActors() cid.Cid {
+{{if (le .v 7)}}
+	return cid.Undef
+{{else}}
+	return s.State.BuiltinActors
+{{end}}
 }

chain/actors/builtin/system/system.go

@@ -4,6 +4,7 @@ import (
 	"github.com/filecoin-project/lotus/chain/actors"
 	"github.com/filecoin-project/lotus/chain/actors/adt"
 	"github.com/filecoin-project/lotus/chain/types"
+	"github.com/ipfs/go-cid"
 
 	"golang.org/x/xerrors"
 
@@ -103,4 +104,5 @@ func MakeState(store adt.Store, av actors.Version) (State, error) {
 
 type State interface {
 	GetState() interface{}
+	GetBuiltinActors() cid.Cid
 }

chain/actors/builtin/system/v0.go

@@ -33,3 +33,9 @@ type state0 struct {
 func (s *state0) GetState() interface{} {
 	return &s.State
 }
+
+func (s *state0) GetBuiltinActors() cid.Cid {
+
+	return cid.Undef
+
+}

chain/actors/builtin/system/v2.go

@@ -33,3 +33,9 @@ type state2 struct {
 func (s *state2) GetState() interface{} {
 	return &s.State
 }
+
+func (s *state2) GetBuiltinActors() cid.Cid {
+
+	return cid.Undef
+
+}

chain/actors/builtin/system/v3.go

@@ -33,3 +33,9 @@ type state3 struct {
 func (s *state3) GetState() interface{} {
 	return &s.State
 }
+
+func (s *state3) GetBuiltinActors() cid.Cid {
+
+	return cid.Undef
+
+}

chain/actors/builtin/system/v4.go

@@ -33,3 +33,9 @@ type state4 struct {
 func (s *state4) GetState() interface{} {
 	return &s.State
 }
+
+func (s *state4) GetBuiltinActors() cid.Cid {
+
+	return cid.Undef
+
+}

chain/actors/builtin/system/v5.go

@@ -33,3 +33,9 @@ type state5 struct {
 func (s *state5) GetState() interface{} {
 	return &s.State
 }
+
+func (s *state5) GetBuiltinActors() cid.Cid {
+
+	return cid.Undef
+
+}

chain/actors/builtin/system/v6.go

@@ -33,3 +33,9 @@ type state6 struct {
 func (s *state6) GetState() interface{} {
 	return &s.State
 }
+
+func (s *state6) GetBuiltinActors() cid.Cid {
+
+	return cid.Undef
+
+}

chain/actors/builtin/system/v7.go

@@ -33,3 +33,9 @@ type state7 struct {
 func (s *state7) GetState() interface{} {
 	return &s.State
 }
+
+func (s *state7) GetBuiltinActors() cid.Cid {
+
+	return cid.Undef
+
+}