12 Commits

Author SHA1 Message Date
Joe Tsai
b2f66bedb4 reflect/prototype: initial commit
Add the prototype package which provides constructors for
protoreflect.{Enum,Message,Extension}Type.

Switch all usages of the internal/prototype equivalent to the new package.
Switch all custom implementions of {Enum,Message}Type to the new package.

Change-Id: Ia9dae6fed4f2b90e55c123627044a7faf098c4b1
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/178438
Reviewed-by: Damien Neil <dneil@google.com>
2019-05-22 18:28:03 +00:00
Damien Neil
e89e6244e0 all: change module to google.golang.org/protobuf
Temporarily remove go.mod, since we can't generate an accurate one until
the corresponding v1 change is submitted.

Change-Id: I1e1ad97f2b455e33f61ffaeb8676289795e47e72
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177000
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-05-14 17:28:29 +00:00
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
Damien Neil
82a0306187 internal/{fileinit,impl}: minimal weak field support
Weak fields are an obsolete proto1 feature. They have been superseded
by extensions. However, some vestigial support for weak fields does
remain, mostly as Google-internal patches. (They aren't exciting;
extensions really do everything weak fields do in a cleaner and
more portable fashion.)

At the moment, the only visible impact of marking a field [weak=true]
is to exclude it from "internal/fileinit".FileBuilder.DependencyIndexes.
We want to preserve that behavior just in case we ever do add full weak
field support here.

Extend fileinit to look up message descriptors for weak fields in the
global registry. If the descriptor cannot be found, use a placeholder
instead.

Remove special-case handling of weak fields in the impl package. The
code generator doesn't do anything special for them, so they can be
treated as any other field.

Change-Id: Ifa2ee3d30d63680a0eeb59c66ebc9521f38fd660
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/175997
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-05-08 17:24:54 +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
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
ca46d8c924 internal/fieldnum: generate field numbers for the google.protobuf package
Generate field numbers for the well-known types,
so that encoding/jsonpb can benefit from them as well.

This CL fixes internal/cmd/generate-protos, which was silently failing
because the modulePath was not properly initialized. We fix this by
moving it to the start of the init function.

Change-Id: I87637176f29218cffa512b4baa49f39dae924061
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/168497
Reviewed-by: Herbie Ong <herbie@google.com>
2019-03-21 00:57:40 +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
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
Joe Tsai
1af1de0c15 internal/cmd/generate-protos: generate internal descfield package
Generate a list of descriptor fields from the descriptor.proto itself
as an internal package. Use these fields for the internal implementation.

Change-Id: Ib1ab0c5c6deb332ba6c8018ef55136b7e5974944
Reviewed-on: https://go-review.googlesource.com/c/164864
Reviewed-by: Herbie Ong <herbie@google.com>
2019-03-02 23:16:45 +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