use isvalid for determining validity and remove vtproto from buildctl

Signed-off-by: Jonathan A. Sternberg <[email protected]>

Author: jsternberg

client/llb/marshal.go

@@ -6,6 +6,7 @@ import (
 	"github.com/containerd/platforms"
 	"github.com/moby/buildkit/solver/pb"
 	digest "github.com/opencontainers/go-digest"
+	"google.golang.org/protobuf/proto"
 )
 
 // Definition is the LLB definition structure with per-vertex metadata entries
@@ -49,7 +50,7 @@ func (def *Definition) Head() (digest.Digest, error) {
 	last := def.Def[len(def.Def)-1]
 
 	var pop pb.Op
-	if err := pop.UnmarshalVT(last); err != nil {
+	if err := proto.Unmarshal(last, &pop); err != nil {
 		return "", err
 	}
 	if len(pop.Inputs) == 0 {
@@ -74,7 +75,7 @@ func ReadFrom(r io.Reader) (*Definition, error) {
 		return nil, err
 	}
 	var pbDef pb.Definition
-	if err := pbDef.UnmarshalVT(b); err != nil {
+	if err := proto.Unmarshal(b, &pbDef); err != nil {
 		return nil, err
 	}
 	var def Definition

cmd/buildctl/build.go

@@ -30,6 +30,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/urfave/cli"
 	"golang.org/x/sync/errgroup"
+	"google.golang.org/protobuf/proto"
 )
 
 var buildCommand = cli.Command{
@@ -126,7 +127,7 @@ func read(r io.Reader, clicontext *cli.Context) (*llb.Definition, error) {
 	if clicontext.Bool("no-cache") {
 		for _, dt := range def.Def {
 			var op pb.Op
-			if err := op.UnmarshalVT(dt); err != nil {
+			if err := proto.Unmarshal(dt, &op); err != nil {
 				return nil, errors.Wrap(err, "failed to parse llb proto op")
 			}
 			dgst := digest.FromBytes(dt)