15 Commits

Author SHA1 Message Date
Joe Tsai
0fc49f8225 reflect/protoreflect: add Descriptor specific methods
Added methods:
	Enum.Descriptor
	Message.Descriptor
	EnumType.Descriptor
	MessageType.Descriptor
	ExtensionType.Descriptor
	Message.New

All functionality is switched over to use those methods instead of
implicitly relying on the fact that {Enum,Message}Type implicitly
implement the associated descriptor interface.

This CL does not yet remove {Enum,Message}.Type or prevent
{Enum,Message,Extension}Type from implementating a descriptor.
That is a subsequent CL.

The Message.New method is also added to replace functionality
that will be lost when the Type methods are removed.

Change-Id: I7fefde1673bbd40bfdac489aca05cec9a6c98eb1
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/174918
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Herbie Ong <herbie@google.com>
2019-05-13 19:34:41 +00:00
Joe Tsai
c90b6ada23 reflect/protoreflect: remove methods with Type suffix
CL/172238 added equivalent methods without the Type suffix,
while keeping the old methods.
CL/172582 updates the v1 codebase to use the new methods.
This CL removes the methods with the Type suffix.

Change-Id: Iaaaa4fff11cac1694735657db2e5fd7cadc90afe
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/173138
Reviewed-by: Herbie Ong <herbie@google.com>
2019-04-20 08:14:13 +00:00
Joe Tsai
d24bc72368 reflect/protoreflect: rename methods with Type suffix
The protobuf type system uses the word "descriptor" instead of "type".
We should avoid the "type" verbage when we aren't talking about Go types.
The old names are temporarily kept around for compatibility reasons.

Change-Id: Icc99c913528ead011f7a74aa8399d9c5ec6dc56e
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/172238
Reviewed-by: Herbie Ong <herbie@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
2019-04-20 06:35:24 +00:00
Joe Tsai
e089c0f929 internal/fileinit: add FileDescriptor.ProtoLegacyRawDesc method
Add a ProtoLegacyRawDesc method for v1 registration support.

Change-Id: I4f03d022854c8d79da776610cb7d75ba9976334f
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/172241
Reviewed-by: Damien Neil <dneil@google.com>
2019-04-16 18:51:45 +00:00
Damien Neil
2300c18725 reflect/protoreflect, reflect/protoregistry: move descriptor lookup to registry
Drop the protoreflect.FileDescriptor.DescriptorByName method.
Descriptor lookup will always happen through a protoregistry.Files, which
is more generally useful (it's rare that you want to find a descriptor in a
specific file, as opposed to a package which may be composed of multiple files).

Split protoregistry.Files descriptor lookup into individual per-type functions
(enum, message, extension, service), matching the preg.Types API.

Drop the ability to look up enum values, message fields, and service methods
for now. This can be easily added later if needed, and is trivial to implement
in user code. (e.g., look up the service and then consult sd.Methods.ByName().)

Change-Id: I2b3d8ef888921a8464ba1434eddab20c7d3a458e
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/172118
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-04-16 06:03:04 +00:00
Joe Tsai
a2dd228004 internal/fileinit: make fileinit responsible for registering concrete options types
Changes:
* Remove protoreflect.OptionsMessage and use protoreflect.ProtoMessage
now that the generated options natively implement reflection.
* Make registration of concrete option types the responsibility of
internal/fileinit since the init logic of descriptor.pb.go uses that.
* Remove equivalent logic in protoc-gen-go to special-case descriptor.

Change-Id: Id814651fafa4d888ff4532d59c6a4f9b68145157
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/171465
Reviewed-by: Damien Neil <dneil@google.com>
2019-04-15 20:37:10 +00:00
Joe Tsai
a5f43e834e internal/fileinit: add scary warnings about compatibility
Change-Id: I4c2f06ed5b06bf481b585ed58ed1c54647843c79
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/171466
Reviewed-by: Herbie Ong <herbie@google.com>
2019-04-11 00:38:23 +00:00
Joe Tsai
35ec98fdcb cmd/protoc-gen-go: generate for v2-only dependencies
This removes yet another set of dependencies of v2 on v1.
The only remaining dependency are in the _test.go files,
primarily for proto.Equal.

Changes made:
* cmd/protoc-gen-go no longer generates any functionality that depends
on the v1 package, and instead only depends on v2.
* internal/fileinit.FileBuilder.MessageOutputTypes is switched from
protoreflect.MessageType to protoimpl.MessageType since the
implementation must be fully inialized before registration occurs.
* The test for internal/legacy/file_test.go is switched to a legacy_test
package to avoid a cyclic dependency.
This requires Load{Enum,Message,File}Desc to be exported.

Change-Id: I43e2fe64cff4eea204258ce11e791aca5eb6e569
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/169298
Reviewed-by: Damien Neil <dneil@google.com>
2019-03-26 17:03:31 +00:00
Joe Tsai
4fddebafc0 all: move v1 types over to the v2 repository
As a goal, v2 should not depend on v1. As another step towards that end,
we move all the types that used to be in the v1 protoapi package over to v2.

For now, we place MessageV1, ExtensionRangeV1, and ExtensionDescV1
in runtime/protoiface since these are types that generated messages will
probably have to reference forever. An alternative location could be
reflect/protoreflect, but it seems unfortunate to have to dirty the
namespace of that package with these types.

We move ExtensionFieldV1, ExtensionFieldsV1, and ExtensionFieldsOf
to internal/impl, since these are related to the implementation of a
generated message.

Since moving these types from v1 to v2 implies that the v1 protoapi
package is useless, we update all usages of v1 protoapi in the v2
repository to point to the relevant v2 type or functionality.

CL/168538 is the corresponding change to alter v1.
There will be a temporary build failure as it is not possible
to submit CL/168519 and CL/168538 atomically.

Change-Id: Ide4025c1b6af5b7f0696f4b65b988b4d10a50f0b
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/168519
Reviewed-by: Herbie Ong <herbie@google.com>
2019-03-22 20:01:07 +00:00
Joe Tsai
4532dd7969 internal/fileinit: prevent map entry descriptors from implementing MessageType
The protobuf type system hacks the representation of map entries into that
of a pseudo-message descriptor.

Previously, we made all message descriptors implement MessageType
where type descriptors had a GoType method that simply returned nil.
Unfortunately, this violates a nice property in the Go type system
where being able to assert to a MessageType guarantees that Go type
information is truly associated with that descriptor.

This CL makes it such that message descriptors for map entries
do not implement MessageType.

Change-Id: I23873cb71fe0ab3c0befd8052830ea6e53c97ca9
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/168399
Reviewed-by: Damien Neil <dneil@google.com>
2019-03-21 17:47:49 +00:00
Joe Tsai
1321a0e05b cmd/protoc-gen-go: generate descriptor proto using v2 textpb
Changes:
* Modify protoc-gen-go to use a helper from internal/impl
to print the message as text.
* Add a helper function to internal/impl that calls v2 textpb.
* Modify encoding/textpb to avoid depending on descriptor proto,
which would cause an import cycle.
* Modify internal/fileinit to populate a pseudo-internal
method on MessageDescriptor to check whether the message should
use the message set wire format. We avoid adding this to the
main MessageDescriptor interface since message sets are a
deprecated proto1 feature that we should avoid promoting.

Change-Id: Ibaf79a563af695756f11ddc4db69b38e25a8f1a7
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/168439
Reviewed-by: Herbie Ong <herbie@google.com>
2019-03-20 20:58:24 +00:00
Joe Tsai
08cd8842f1 cmd/protoc-gen-go: register with the v2 registry for descriptor
By passing the global registries to fileinit.Builder, the Build
method can register the newly constructed descriptors on our behalf.
As a result, we can stop registering with the v1 registries as well.

We only do this for descriptor proto to remove another dependency on v1.
We deliberately keep the v1 registration logic for now to make it easy
to patch away this new behavior.

Change-Id: Ic6aa8ffba3d2d0abe08a61fc5e1c9ca7668e0988
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/168000
Reviewed-by: Herbie Ong <herbie@google.com>
2019-03-19 05:04:43 +00:00
Joe Tsai
afb455eaf8 cmd/protoc-gen-go: correlate v1 ExtensionDesc with v2 ExtensionType
Unfortunately a good amount of code uses pointer comparisons on the
v1 ExtensionDesc to determine exactly which extension field is set,
rather than checking whether the extension descriptor semantically
describes the field that they are interested in.

To preserve this behavior in v1, we need a 1:1 mapping between
a v2 ExtensionType and a specific v1 ExtensionDesc.

Change-Id: I852b3cefb4585bd656e48e5adad6cc28795d02df
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/167759
Reviewed-by: Damien Neil <dneil@google.com>
2019-03-15 01:24:42 +00:00
Joe Tsai
990b9f5919 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>
2019-03-13 20:17:00 +00:00
Damien Neil
8012b444ee internal/fileinit: generate reflect data structures from raw descriptors
This CL takes a significantly different approach to generating support
for protobuf reflection. The previous approach involved generating a
large number of Go literals to represent the reflection information.
While that approach was correct, it resulted in too much binary bloat.

The approach taken here initializes the reflection information from
the raw descriptor proto, which is a relatively dense representation
of the protobuf reflection information. In order to keep initialization
cost low, several measures were taken:
* At program init, the bare minimum is parsed in order to initialize
naming information for enums, messages, extensions, and services declared
in the file. This is done because those top-level declarations are often
relevant for registration.
* Only upon first are most of the other data structures for protobuf
reflection actually initialized.
* Instead of using proto.Unmarshal, a hand-written unmarshaler is used.
This allows us to avoid a dependendency on the descriptor proto and also
because the API for the descriptor proto is fundamentally non-performant
since it requires an allocation for every primitive field.

At a high-level, the new implementation lives in internal/fileinit.

Several changes were made to other parts of the repository:
* cmd/protoc-gen-go:
  * Stop compressing the raw descriptors. While compression does reduce
the size of the descriptors by approximately 2x, it is a pre-mature
optimization since the descriptors themselves are around 1% of the total
binary bloat that is due to generated protobufs.
  * Seeding protobuf reflection from the raw descriptor significantly
simplifies the generator implementation since it is no longer responsible
for constructing a tree of Go literals to represent the same information.
  * We remove the generation of the shadow types and instead call
protoimpl.MessageType.MessageOf. Unfortunately, this incurs an allocation
for every call to ProtoReflect since we need to allocate a tuple that wraps
a pointer to the message value, and a pointer to message type.
* internal/impl:
  * We add a MessageType.GoType field and make it required that it is
set prior to first use. This is done so that we can avoid calling
MessageType.init except for when it is actually needed. The allows code
to call (*FooMessage)(nil).ProtoReflect().Type() without fearing that the
init code will run, possibly triggering a recursive deadlock (where the
init code depends on getting the Type of some dependency which may be
declared within the same file).
* internal/cmd/generate-types:
  * The code to generate reflect/prototype/protofile_list_gen.go was copied
and altered to generated internal/fileinit.desc_list_gen.go.

At a high-level this CL adds significant technical complexity.
However, this is offset by several possible future changes:
* The prototype package can be drastically simplified. We can probably
reimplement internal/legacy to use internal/fileinit instead, allowing us
to drop another dependency on the prototype package. As a result, we can
probably delete most of the constructor types in that package.
* With the prototype package significantly pruned, and the fact that generated
code no longer depend on depends on that package, we can consider merging
what's left of prototype into protodesc.

Change-Id: I6090f023f2e1b6afaf62bd3ae883566242e30715
Reviewed-on: https://go-review.googlesource.com/c/158539
Reviewed-by: Herbie Ong <herbie@google.com>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-01-30 01:33:46 +00:00