32 Commits

Author SHA1 Message Date
Joe Tsai
01887a85f5 reflect/protoreflect: remove FieldDescriptor.{Oneof,Extendee} methods
This is a breaking change in light of new methods added in CL/176977.

This removes:
	FieldDescriptor.Oneof: replacement is ContainingOneof
	FieldDescriptor.Extendee: replacement is IsExtension and ContainingMessage

Change-Id: I82008e46fb3b80de8e8a0ac42afc54e8c4b67411
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/176942
Reviewed-by: Damien Neil <dneil@google.com>
2019-06-17 19:43:30 +00:00
Joe Tsai
a93fdf5404 reflect/protoreflect: remove bool output for Descriptor.Parent method
This is a breaking change.

The equivalent replacement logic is to trivially check whether the
parent descriptor is not nil.

Change-Id: I5c89c1d9f29f9e6f721bbfbcf7774188d8f0086a
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/175987
Reviewed-by: Damien Neil <dneil@google.com>
2019-06-17 19:43:22 +00:00
Joe Tsai
378c1329de reflect/protoreflect: add alternative message reflection API
Added API:
	Message.Len
	Message.Range
	Message.Has
	Message.Clear
	Message.Get
	Message.Set
	Message.Mutable
	Message.NewMessage
	Message.WhichOneof
	Message.GetUnknown
	Message.SetUnknown

Deprecated API (to be removed in subsequent CL):
	Message.KnownFields
	Message.UnknownFields

The primary difference with the new API is that the top-level
Message methods are keyed by FieldDescriptor rather than FieldNumber
with the following semantics:
* For known fields, the FieldDescriptor must exactly match the
field descriptor known by the message.
* For extension fields, the FieldDescriptor must implement ExtensionType,
where ContainingMessage.FullName matches the message name, and
the field number is within the message's extension range.
When setting an extension field, it automatically stores
the extension type information.
* Extension fields are always considered nullable,
implying that repeated extension fields are nullable.
That is, you can distinguish between a unpopulated list and an empty list.
* Message.Get always returns a valid Value even if unpopulated.
The behavior is already well-defined for scalars, but for unpopulated
composite types, it now returns an empty read-only version of it.

Change-Id: Ia120630b4db221aeaaf743d0f64160e1a61a0f61
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/175458
Reviewed-by: Damien Neil <dneil@google.com>
2019-06-17 17:33:24 +00:00
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
Joe Tsai
4fe9663f4c internal/impl: rename MessageType as MessageInfo
The name MessageType is easily confused with protoreflect.MessageType.
Rename it as MessageInfo, which follows the pattern set by v1,
where the equivalent data structure is called InternalMessageInfo.

Change-Id: I535956e1f7c6e9b07e9585e889d5e93388d0d2ce
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/178478
Reviewed-by: Damien Neil <dneil@google.com>
2019-05-22 14:54:35 +00:00
Joe Tsai
63bdd1f864 internal/descfmt: rename from typefmt
The name descfmt more closely matches the fact that this package
provides pretty-printing for descriptors.

Change-Id: I11b0e4a0302962ee7bbf315fb259d050847cadbb
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/178479
Reviewed-by: Damien Neil <dneil@google.com>
2019-05-22 14:46:27 +00:00
Joe Tsai
a95b29fbf6 types: consistently name generated protos
Rename each generated protobuf package such that the base of the
Go package path is always equal to the Go package name to follow
proper Go package naming conventions.

The Go package name is derived from the .proto source file name by
replacing ".proto" with "pb" and stripping all underscores.

Change-Id: Iea05d1b5d94b1b2821ae10276ab771bb2df93c0e
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177380
Reviewed-by: Damien Neil <dneil@google.com>
2019-05-16 21:55:40 +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
ac31a352ca reflect/protoreflect: add helper methods to FieldDescriptor
Added API:
	FieldDescriptor.IsExtension
	FieldDescriptor.IsList
	FieldDescriptor.MapKey
	FieldDescriptor.MapValue
	FieldDescriptor.ContainingOneof
	FieldDescriptor.ContainingMessage

Deprecated API (to be removed in subsequent CL):
	FieldDescriptor.Oneof
	FieldDescriptor.Extendee

These methods help cleanup several common usage patterns.

Change-Id: I9a3ffabc2edb2173c536509b22f330f98bba7cf3
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/176977
Reviewed-by: Damien Neil <dneil@google.com>
2019-05-14 17:14:05 +00:00
Joe Tsai
67c1d9b2c1 reflect/protoreflect: add Descriptor.ParentFile
Querying for the parent file that contains a descriptor declaration
is a common enough operation to warrant its own first-class method.

Change-Id: I2f41e5126a5b465df23897904a6513dd3ed8dd92
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/176777
Reviewed-by: Damien Neil <dneil@google.com>
2019-05-13 20:21:18 +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
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
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
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
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
Joe Tsai
19058431cd internal/cmd/generate-protos: initial commit
Create a single binary for handling generation of protos.
This replaces previous logic spread throughout the repo in:
* regenerate.bash
* cmd/protoc-gen-go/golden_test.go
* cmd/protoc-gen-go-grpc/golden_test.go
* (indirectly) internal/protogen/goldentest

One of the problems with the former approaches is that they relied on
a version of protoc that was specific to a developer's workstation.
This meant that the result of generation was not hermetic.
To address this, we rely on the hard-coded version of protobuf specified
in the test.bash script.

A summary of changes in this CL are:
* The internal_gengo.GenerateFile and internal_gengogrpc.GenerateFile
functions are unified to have consistent signatures. It seems that the
former accepted a *protogen.GeneratedFile to support v1 where gRPC code
was generated into the same file as the base .pb.go file. However, the
same functionality can be achieved by having the function return
the generated file object.
* The test.bash script patches the protobuf toolchain to have properly
specified go_package options in each proto source file.
* The test.bash script accepts a "-regenerate" argument.
* Add generation for the well-known types. Contrary to how these were
laid out in the v1 repo, all the well-known types are placed in the
same Go package.
* Add generation for the conformance proto.
* Remove regenerate.bash
* Remove internal/protogen
* Remove cmd/protoc-gen-go/golden_test.go
* Remove cmd/protoc-gen-go-grpc/golden_test.go
* Add cmd/protoc-gen-go/annotation_test.go

Change-Id: I4a1a97ae6f66e2fabcf4e4d292c95ab2a2db0248
Reviewed-on: https://go-review.googlesource.com/c/164477
Reviewed-by: Damien Neil <dneil@google.com>
2019-03-01 20:47:52 +00:00
Joe Tsai
4069211bcd protogen: use full path for generated file variable name
Use the full path (including the extension) for the generation of
the per-file variable name. Several reasons for this:

* The current logic is buggy in the case where pathType == pathTypeImport
since the prefix variable will be mangled with the Go import path.

* The extension is technically part of the path.
Thus, "path/to/foo.proto" and "path/to/foo.protodevel" are two
distinctly different imports.

* Style-wise, it subjectively looks better. Rather than being a mixture
of camelCase and snake_case, it is all snake_case for the common case:
	before: ProtoFile_google_protobuf_any
	after:  File_google_protobuf_any_proto

* Since the extension is almost always ".proto", this results in a
suffix of "_proto", which provides an additional layer of protection
against possible name conflicts. The previous approach could possibly
have a conflict between "Foo.proto" and a message named ProtoFile
with a sub-message called Foo.

Also, use the per-file variable name for the raw descriptor variables
instead of the hashed version.

Change-Id: Ic91e326b7593e5985cee6ececc60539c27fe32fe
Reviewed-on: https://go-review.googlesource.com/c/164379
Reviewed-by: Damien Neil <dneil@google.com>
2019-03-01 00:13:31 +00:00
Damien Neil
71c6603a26 protogen: use full filename in per-file vars
For a file "foo/bar.proto", put the FileDescriptor in "ProtoFile_foo_bar"
rather than "Bar_fileDescriptor".

Avoid name clashes when a package contains "a/foo.proto" and "b/foo.proto".

Don't camelcase the filename: These vars weren't fully camelcased to begin
with, and leaving the filename relatively unchanged is clearer and more
predictable.

Move "ProtoFile" from the end of the var name to the start, so that vars
will sort better in packages with multiple descriptors.

These changes do add a chance of name collision when the input filename
begins with an uppercase letter: Foo.proto becomes "ProtoFile_Foo", which
could be the result of camelcasing "proto_file.foo". The readability
benefits seem worth it.

Change-Id: If27d3a0d7b5bf3535aa1607a8579eb057c74d2dc
Reviewed-on: https://go-review.googlesource.com/c/163199
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Reviewed-by: Herbie Ong <herbie@google.com>
2019-02-21 22:37:58 +00:00
Damien Neil
e475eaa7ad internal/fileinit: add tests for fileinit and protodesc
Test the fileinit and protodesc packages by verifying that passing a
FileDescriptorProto through a round trip of these packages leaves it
unchanged.

Change-Id: I6bfb894d95f1736f9908adee1ab63e9653b3f1be
Reviewed-on: https://go-review.googlesource.com/c/159762
Reviewed-by: Herbie Ong <herbie@google.com>
2019-01-30 01:34:30 +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