internal/prototype: move from reflect/prototype

The prototype package was initially used by generated reflection support,
but has now been replaced by internal/fileinit.
Eventually, this functionality should be deleted and re-written in terms
of other components in the repo.

Usages that prototype currently provides (but should be moved) are:
* Constructing standalone messages and enums, which is behavior we should
provide in reflect/protodesc. The google.protobuf.{Enum,Type} are well-known
proto messages designed for this purpose.
* Constructing placeholder files, enums, and messages.
* Consructing protoreflect.{Message,Enum,Extension}Types, which are protobuf
descriptors with associated Go type information.

Change-Id: Id7dbefff952682781b439aa555508c59b2629f9e
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/167383
Reviewed-by: Damien Neil <dneil@google.com>

cmd/protoc-gen-go/internal_gengo/reflect.go

@@ -27,7 +27,7 @@ const (
 	reflectPackage      = protogen.GoImportPath("reflect")
 	protoimplPackage    = protogen.GoImportPath("github.com/golang/protobuf/v2/runtime/protoimpl")
 	protoreflectPackage = protogen.GoImportPath("github.com/golang/protobuf/v2/reflect/protoreflect")
-	prototypePackage    = protogen.GoImportPath("github.com/golang/protobuf/v2/reflect/prototype")
+	prototypePackage    = protogen.GoImportPath("github.com/golang/protobuf/v2/internal/prototype")
 )
 
 // TODO: Add support for proto options.

internal/cmd/generate-types/main.go

@@ -40,7 +40,7 @@ func main() {
 	chdirRoot()
 	writeSource("internal/fileinit/desc_list_gen.go", generateFileinitDescList())
 	writeSource("proto/decode_gen.go", generateProtoDecode())
-	writeSource("reflect/prototype/protofile_list_gen.go", generateListTypes())
+	writeSource("internal/prototype/protofile_list_gen.go", generateListTypes())
 }
 
 // chdirRoot changes the working directory to the repository root.

internal/cmd/pbdump/pbdump.go

@@ -19,9 +19,9 @@ import (
 
 	"github.com/golang/protobuf/v2/internal/encoding/pack"
 	"github.com/golang/protobuf/v2/internal/encoding/wire"
+	"github.com/golang/protobuf/v2/internal/prototype"
 	"github.com/golang/protobuf/v2/internal/scalar"
 	"github.com/golang/protobuf/v2/reflect/protoreflect"
-	"github.com/golang/protobuf/v2/reflect/prototype"
 
 	descriptorpb "github.com/golang/protobuf/v2/types/descriptor"
 )

internal/cmd/pbdump/pbdump_test.go

@@ -12,8 +12,8 @@ import (
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 )
 
 func TestFields(t *testing.T) {

internal/encoding/pack/pack_test.go

@@ -11,8 +11,8 @@ import (
 	"math"
 	"testing"
 
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 	cmp "github.com/google/go-cmp/cmp"
 )
 

internal/encoding/tag/tag.go

@@ -12,9 +12,9 @@ import (
 	"strings"
 
 	defval "github.com/golang/protobuf/v2/internal/encoding/defval"
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	scalar "github.com/golang/protobuf/v2/internal/scalar"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 
 	descriptorpb "github.com/golang/protobuf/v2/types/descriptor"
 )

internal/encoding/tag/tag_test.go

@@ -8,8 +8,8 @@ import (
 	"reflect"
 	"testing"
 
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 )

internal/fileinit/desc.go

@@ -14,10 +14,10 @@ import (
 	"sync"
 
 	pragma "github.com/golang/protobuf/v2/internal/pragma"
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pfmt "github.com/golang/protobuf/v2/internal/typefmt"
 	"github.com/golang/protobuf/v2/proto"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 )
 
 // FileBuilder construct a protoreflect.FileDescriptor from the

internal/fileinit/desc_lazy.go

@@ -13,9 +13,9 @@ import (
 	defval "github.com/golang/protobuf/v2/internal/encoding/defval"
 	wire "github.com/golang/protobuf/v2/internal/encoding/wire"
 	pimpl "github.com/golang/protobuf/v2/internal/impl"
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pvalue "github.com/golang/protobuf/v2/internal/value"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 )
 
 func (file *fileDesc) lazyInit() *fileLazy {

internal/impl/export.go

@@ -5,8 +5,8 @@
 package impl
 
 import (
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 )
 
 // Export is a zero-length named type that exists only to export a set of

internal/impl/legacy_test.go

@@ -14,9 +14,9 @@ import (
 	pack "github.com/golang/protobuf/v2/internal/encoding/pack"
 	pimpl "github.com/golang/protobuf/v2/internal/impl"
 	pragma "github.com/golang/protobuf/v2/internal/pragma"
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	scalar "github.com/golang/protobuf/v2/internal/scalar"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 	cmp "github.com/google/go-cmp/cmp"
 	cmpopts "github.com/google/go-cmp/cmp/cmpopts"
 

internal/impl/message_test.go

@@ -13,10 +13,10 @@ import (
 
 	protoV1 "github.com/golang/protobuf/proto"
 	pimpl "github.com/golang/protobuf/v2/internal/impl"
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	scalar "github.com/golang/protobuf/v2/internal/scalar"
 	pvalue "github.com/golang/protobuf/v2/internal/value"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 	cmp "github.com/google/go-cmp/cmp"
 	cmpopts "github.com/google/go-cmp/cmp/cmpopts"
 

internal/legacy/enum.go

@@ -10,9 +10,9 @@ import (
 	"reflect"
 	"sync"
 
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pvalue "github.com/golang/protobuf/v2/internal/value"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 
 	descriptorpb "github.com/golang/protobuf/v2/types/descriptor"
 )

internal/legacy/extension.go

@@ -12,10 +12,10 @@ import (
 	papi "github.com/golang/protobuf/protoapi"
 	ptag "github.com/golang/protobuf/v2/internal/encoding/tag"
 	pimpl "github.com/golang/protobuf/v2/internal/impl"
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pfmt "github.com/golang/protobuf/v2/internal/typefmt"
 	pvalue "github.com/golang/protobuf/v2/internal/value"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 )
 
 // extensionDescKey is a comparable version of protoapi.ExtensionDesc

internal/legacy/extension_test.go

@@ -9,8 +9,8 @@ import (
 
 	papi "github.com/golang/protobuf/protoapi"
 	pimpl "github.com/golang/protobuf/v2/internal/impl"
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 
 	// The legacy package must be imported prior to use of any legacy messages.
 	// TODO: Remove this when protoV1 registers these hooks for you.

internal/legacy/message.go

@@ -13,9 +13,9 @@ import (
 
 	ptag "github.com/golang/protobuf/v2/internal/encoding/tag"
 	pimpl "github.com/golang/protobuf/v2/internal/impl"
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	scalar "github.com/golang/protobuf/v2/internal/scalar"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 
 	descriptorpb "github.com/golang/protobuf/v2/types/descriptor"
 )

internal/prototype/protofile.go

@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// TODO: Delete this package and re-write functionality to depend on
+// reflect/protodesc and internal/fileinit.
+
 // Package prototype provides builders to construct protobuf types that
 // implement the interfaces defined in the protoreflect package.
 //

internal/prototype/type_test.go

@@ -14,10 +14,10 @@ import (
 
 	protoV1 "github.com/golang/protobuf/proto"
 	detrand "github.com/golang/protobuf/v2/internal/detrand"
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	scalar "github.com/golang/protobuf/v2/internal/scalar"
 	pdesc "github.com/golang/protobuf/v2/reflect/protodesc"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 
 	descriptorpb "github.com/golang/protobuf/v2/types/descriptor"
 )

reflect/protodesc/protodesc.go

@@ -12,9 +12,9 @@ import (
 
 	"github.com/golang/protobuf/v2/internal/encoding/defval"
 	"github.com/golang/protobuf/v2/internal/errors"
+	"github.com/golang/protobuf/v2/internal/prototype"
 	"github.com/golang/protobuf/v2/reflect/protoreflect"
 	"github.com/golang/protobuf/v2/reflect/protoregistry"
-	"github.com/golang/protobuf/v2/reflect/prototype"
 
 	descriptorpb "github.com/golang/protobuf/v2/types/descriptor"
 )

reflect/protoregistry/registry_test.go

@@ -14,9 +14,9 @@ import (
 
 	"github.com/golang/protobuf/protoapi"
 	"github.com/golang/protobuf/v2/internal/legacy"
+	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
 	preg "github.com/golang/protobuf/v2/reflect/protoregistry"
-	ptype "github.com/golang/protobuf/v2/reflect/prototype"
 
 	testpb "github.com/golang/protobuf/v2/reflect/protoregistry/testprotos"
 )

types/descriptor/descriptor.pb.go

@@ -5,8 +5,8 @@ package descriptor_proto
 
 import (
 	protoapi "github.com/golang/protobuf/protoapi"
+	prototype "github.com/golang/protobuf/v2/internal/prototype"
 	protoreflect "github.com/golang/protobuf/v2/reflect/protoreflect"
-	prototype "github.com/golang/protobuf/v2/reflect/prototype"
 	protoimpl "github.com/golang/protobuf/v2/runtime/protoimpl"
 	reflect "reflect"
 )