CL/174938 removed these methods in favor of a method that returned
only the descriptors. This CL adds back in the Type methods alongside
the Descriptor methods.
In a vast majority of protobuf usages, only the descriptor information
is needed. However, there is a small percentage that legitimately needs
the Go type information. We should provide both, but document that the
descriptor-only information is preferred.
Change-Id: Ia0a098997fb1bd009994940ae8ea5257ccd87cae
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/184578
Reviewed-by: Damien Neil <dneil@google.com>
Usage of these is pervasive in code which works with proto2, and proto2
will be with us for a long, long time to come. Move them to the proto
package.
Change-Id: I1b2e57429fd5a8f107a848a4492d20c27f304bd7
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185543
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
We define MessageState, which is essentially an atomically set *MessageInfo.
By nesting this as the first field in every generated message, we can
implement the reflective methods on a *MessageState when obtained by
unsafe casting a concrete message pointer as a *MessageState.
The MessageInfo held by MessageState provides additional Go type information
to interpret the memory that comes after the contents of the MessageState.
Since we are nesting a MessageState in every message,
the memory use of every message instance grows by 8B.
On average, the body of ProtoReflect grows from 133B to 202B (+50%).
However, this is offset by XXX_Methods, which is 108B and
will be removed in a future CL. Taking into account the eventual removal
of XXX_Methods, this is a net reduction of 25%.
name old time/op new time/op delta
Name/Value-4 70.3ns ± 2% 17.5ns ± 6% -75.08% (p=0.000 n=10+10)
Name/Nil-4 70.6ns ± 3% 33.4ns ± 2% -52.66% (p=0.000 n=10+10)
name old alloc/op new alloc/op delta
Name/Value-4 16.0B ± 0% 0.0B -100.00% (p=0.000 n=10+10)
Name/Nil-4 16.0B ± 0% 0.0B -100.00% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
Name/Value-4 1.00 ± 0% 0.00 -100.00% (p=0.000 n=10+10)
Name/Nil-4 1.00 ± 0% 0.00 -100.00% (p=0.000 n=10+10)
Change-Id: I92bd58dc681c57c92612fd5ba7fc066aea34e95a
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185460
Reviewed-by: Damien Neil <dneil@google.com>
The logic for this will be removed entirely in a future CL.
Change-Id: I3a20fb2a207fc5bedc550b3f6deeab7f63eaa2c4
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185243
Reviewed-by: Herbie Ong <herbie@google.com>
The encoding/prototext and encoding/protojson are implemented entirely
in terms of protobuf reflection, which side-steps this information.
Remove the hacks in the generator to special-case MessageSet.
Change-Id: I708c4636b77672545a103b7ab686f103b9dfc514
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185240
Reviewed-by: Herbie Ong <herbie@google.com>
We modify protoc-gen-go to stop generating exported XXX fields.
The unsafe implementation is unaffected by this change since unsafe
can access fields regardless of visibility. However, for the purego
implementation, we need to respect Go visibility rules as enforced
by the reflect package.
We work around this by generating a exporter function that given
a reference to the message and the field to export, returns a reference
to the unexported field value. This exporter function is protected by
a constant such that it is not linked into the final binary in non-purego
build environment.
Updates golang/protobuf#276
Change-Id: Idf5c1f158973fa1c61187ff41440acb21c5dac94
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185141
Reviewed-by: Damien Neil <dneil@google.com>
Associate the oneof wrapper types with a message by conveying that
information to the associated MessageInfo.
Change-Id: Iabfca593850e1d6a89498a37eacbf22dbb73bd20
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185239
Reviewed-by: Damien Neil <dneil@google.com>
This test verifies that the inialization logic does not accidentally
execute the lazy initialization logic that is intended to only evaluate
upon first use.
Change-Id: I5e9dea17ce88081c78195af0e86dd38223689f63
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/184259
Reviewed-by: Damien Neil <dneil@google.com>
This does not remove all dependencies,
but all of the cases where it can now be implemented in terms of v2.
Change-Id: Idc5b0273f0d35c284bf2141eb9cce998692ceb15
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/184878
Reviewed-by: Herbie Ong <herbie@google.com>
If we were starting from scratch, we would not have added the enum maps.
However, they already exist and see a fair amount of usage.
The effort to remove them is not worth it. Thus, remove the deprecation
warning since they are here to stay.
Note that the generated code does not refer to the generated enum maps.
One day, the linker should be able to elide them if unused by the user.
However, https://golang.org/issue/2559 would need to be resolved first.
Change-Id: Ia8b9b1812b5d8462ca2fa1d543170e4a09ff9e4f
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/183177
Reviewed-by: Damien Neil <dneil@google.com>
The internal/fileinit package is split apart into two packages:
* internal/filedesc constructs descriptors from the raw proto.
It is very similar to the previous internal/fileinit package.
* internal/filetype wraps descriptors with Go type information
Overview:
* The internal/fileinit package will be deleted in a future CL.
It is kept around since the v1 repo currently depends on it.
* The internal/prototype package is deleted. All former usages of it
are now using internal/filedesc instead. Most significantly,
the reflect/protodesc package was almost entirely re-written.
* The internal/impl package drops support for messages that do not
have a Descriptor method (pre-2016). This removes a significant amount
of technical debt.
filedesc.Builder to parse raw descriptors.
* The internal/encoding/defval package now handles enum values by name.
Change-Id: I3957bcc8588a70470fd6c7de1122216b80615ab7
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/182360
Reviewed-by: Damien Neil <dneil@google.com>
This is a breaking change in light of new methods added in CL/174918.
This removes:
Enum.Type: replacement is Descriptor
Message.Type: replacement is Descriptor and New
Change-Id: Iaa5328795407c8401ef14ed038bd5ace19d8e03b
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/174938
Reviewed-by: Damien Neil <dneil@google.com>
This is a breaking change in light of API added in CL/182497.
This removes:
Files.RangeFilesByPath: replacement is Files.FindFileByPath
Change-Id: I47bf59b37c355844984661056212953853a0db51
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/182537
Reviewed-by: Damien Neil <dneil@google.com>
CL/180577 removes direct access to the Desc field in v1.
Since the only way to access the type is through {Has,Get,Set}Type,
we can now unexport the field and change the underlying type.
Change-Id: I6cc7018d4326c17228ba579d6161c5fb3f6d4127
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/180578
Reviewed-by: Damien Neil <dneil@google.com>
Generate the needed infrastructure to ensure that we can statically
enforce minimum and maximum versions. This enables us to have a policy
when we release v2 where it fails to build for:
* new generated code with really old runtimes
* new runtimes with really old generated code
Change-Id: Ib699ad62c06dff8f9285806394a741c18db00288
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/178546
Reviewed-by: Damien Neil <dneil@google.com>
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>
A proto2 message can reference a proto3 enum. It is currently cumbersome
to set proto3 enums in proto2 messages. Add the Enum method in all situations
to support this situation. It also removes yet another point of divergence
between proto2 and proto3.
We could consider removing this method if Go ever gets generics,
but that hypothetical future is long ways away.
Change-Id: Ib83bc87e46b49f3271b90bacb2893bb8e278e4f2
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177257
Reviewed-by: Damien Neil <dneil@google.com>
CL/177623 updates v1 to not depend on the previous import paths.
Change-Id: I46a61b8f8fa136c9c1fe367ff311732ba8841279
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177604
Reviewed-by: Damien Neil <dneil@google.com>
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>
CL/177620 modifies v1 to stop touching the Value field directly,
such that it is now unexport the Value field.
Change-Id: I0a05bbe59146862fc77c261349d7d90d6fa312e0
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177621
Reviewed-by: Damien Neil <dneil@google.com>
Rename encoding/*pb to follow the convention of prefixing package names
with 'proto':
google.golang.org/protobuf/encoding/protojson
google.golang.org/protobuf/encoding/prototext
Move protogen under a compiler/ directory, just in case we ever do add
more compiler-related packages.
google.golang.org/protobuf/compiler/protogen
Change-Id: I31010cb5cabcea8274fffcac468477b58b56e8eb
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177178
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
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>
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>
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>
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>
CL/175579 switches v2 to use XXX_unrecognized exclusively.
CL/175838 switches v1 to use XXX_unrecognized exclusively.
This means that it is now safe to delete the Raw field.
Change-Id: Ic60c58147c2df4078e72c34d1202d226a7ea4bed
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/175839
Reviewed-by: Damien Neil <dneil@google.com>
This covers most of the TODO around validation. I left open the ones
that we didn't have clear consensus on yet.
Change-Id: I336c53173ee8d7447558b1e3a0c1ef945e986cd5
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/175140
Reviewed-by: Joe Tsai <joetsai@google.com>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
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>
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>
These deprecated features add a non-trivial amount of binary bloat.
Protect these under a constant to make it easy to patch them out.
Change-Id: I12cc33613c19ef60ceec4c4449d0cf3692835170
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/172407
Reviewed-by: Damien Neil <dneil@google.com>
Using a named fields gives us the flexibility to change the underlying
representation of special fields without needing to regenerate user code.
We add a named type for ExtensionFields, UnknownFields, and SizeCache.
Change-Id: I107cf82899850ea76665310ce79def60f0f7ab97
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/172402
Reviewed-by: Damien Neil <dneil@google.com>
Lower-casing the FileDescriptor variable provides for shorter and
more readable global variable names. This has a very minor benefit
that the read-only data section of a binary is slightly smaller
since function names do end up in the final binary.
Change-Id: I077364905e5c9adea69873b3ea580fddc68b9eb8
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/172119
Reviewed-by: Herbie Ong <herbie@google.com>
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>
Go1.12 on GoLLVM with LLVM 9.0.0 has a bug where the simpler but
equivalent expression results in memory corruption.
Revert to the more complex expression to avoid breaking GoLLVM and
it is not worth waiting for a GoLLVM fix.
Change-Id: I8b42965ca9bd333deb8693021e7b22f966e13521
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/171463
Reviewed-by: Damien Neil <dneil@google.com>
Seperate out the generation of the oneof wrapper types from the
code block that is about getter methods.
Change-Id: Ief44ef953d0b5ad8c998a8542c830ca70468a3bf
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/171029
Reviewed-by: Damien Neil <dneil@google.com>
Allow message implementations to provide optimized versions of standard
operations. Generated messages now include a ProtoReflectMethods method,
returning a protoiface.Methods struct containing pointers to assorted
optional functions.
The Methods struct also includes a Flags field indicating support for
optional features such as deterministic marshaling.
Implementation of the fast paths (and tests) will come in later CLs.
Change-Id: Idd1beed0ecf43ec5e5e7b8da2ee1e08d3ce32213
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/170340
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Minor changes:
* Use x as the receiver since "e" and "m" are meaningless in the presence
of user-defined enum and message names.
* Consistently keep enum methods together, rather awkwardly split apart
by the value maps.
Change-Id: I68e5666efb56ac7a4d062fb223b9f826dc72aba9
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/170357
Reviewed-by: Herbie Ong <herbie@google.com>
This reduces the init-time cost slightly since the GZIP'd
raw descriptor is constructed lazily on demand.
Change-Id: I482c6a2201b8786e425d7dee5612fdfd60ab1500
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/169917
Reviewed-by: Herbie Ong <herbie@google.com>
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>
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>
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>
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>
The v1 registration leaks the message types out to the proto package.
When doing that, it must ensure that the reflection data structures
for those types are properly initialized first. We achieve that by
doing v1 registration at the end of the reflection init function.
Change-Id: If6df18df59d05bad50ff39c2eff6beb19e7466cc
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/168348
Reviewed-by: Damien Neil <dneil@google.com>
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>
This CL breaks another dependency of v2 on v1.
A missing feature in v2 is proto.Clone, but we can use a
Marshal/Unmarshal roundtrip to achieve the same effect
as a temporary stop-gap.
Change-Id: I9d0432fd3efe9fc8b34db6c5a1eabbef0c36277c
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/168217
Reviewed-by: Damien Neil <dneil@google.com>
The EnumName, UnmarshalJSONEnum, and CompressGZIP helpers currently live
in v1 protoapi, which would cause all generated messages to depend on v1.
In an effort to break the dependency of v2 on v1, we move these helper
functions to v2 (and re-written to take advantage of protobuf reflection).
These helpers are unfortunate, but we cannot eliminate the functionality
that they implement since they are exposed in the publicly generated API.
Since EnumName does not rely on the enum maps, it removes another dependency
on those variables. Eventually, we can get to the point where these variables
(though declared) are not linked into the binary if the user does not use them.
Also, we rely on the v1 proto package for registration instead of v1 protoapi.
This may re-introduce a cyclic dependency on descriptor proto again in the
future, but the better approach is to just start registering with v2.
Change-Id: Id755585a7a1df14e4a6a2dfa650df221a3c153fb
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/167921
Reviewed-by: Damien Neil <dneil@google.com>
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>
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>
Now that binary bloat concerns have been addressed, remove the flag
to control whether to generate support for reflection.
Change-Id: Ia0d11183707572caaf91d2f01dfa77e3aac0a417
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/167140
Reviewed-by: Damien Neil <dneil@google.com>
The go.sum is not particularly important for the testdata directory,
so ignore it.
Change-Id: I069613deda2af4944d09aed34008fec201df6bb4
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/166879
Reviewed-by: Herbie Ong <herbie@google.com>
Running "go build ./..." does not descend into testdata directories.
However, the testdata in this repository is source code that is
intended to build properly. We could rename the directory, but that does
not test whether the generated packages can initialize properly.
Thus, we generate a trivial test that simply blank imports all packages.
Doing this reveals that some of the generated files have incorrect imports,
leading to registration conflicts.
To avoid introducing a dependency on gRPC from our go.mod file, we put
the testdata directories in their own module. Also, we avoid running
internal/testprotos through the grpc plugin because the servie and method
definitions in that directory are more for testing proto file initialization
rather than testing grpc generation.
Change-Id: Iaa6a06449787a085200e31bc7606e3ac904d3180
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/164917
Reviewed-by: Damien Neil <dneil@google.com>
Ensure that the init funcs for files within a Go package run in the
dependency order of the source .proto files. That is, if a.proto and b.proto
are part of the same Go package, and a.proto imports b.proto, then b.pb.go's
init funcs must run before a.pb.go's.
Change-Id: I0e86ff22e5c4cab9df7a73fe4805390fadd34b0d
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/166419
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Reviewed-by: Herbie Ong <herbie@google.com>
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>
Using arrays in the generated reflection information adds unnecessary
eq and hash functions being added to the package. Change to slices
to reduce bloat.
Change-Id: I1a4f6d59021644d93dd6c24679b9233141e89a75
Reviewed-on: https://go-review.googlesource.com/c/164640
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
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>
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>
Calling a helper function directly should reduce binary bloat slightly.
Change-Id: I6068dc4cd00c8d90d2e6e6d99633b81388bc8781
Reviewed-on: https://go-review.googlesource.com/c/164679
Reviewed-by: Damien Neil <dneil@google.com>
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>
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>
A "_ProtoFile" suffix can potentially conflict with a sub-message named
"ProtoFile" nested within a message that matches the camel-cased
form of the basename of the .proto source file.
Avoid unlikely conflicts and rename this to use a "_protoFile" suffix,
which can never conflict except with an enum value that is also named
"protoFile" (which is a violation of the style guide).
Change-Id: Ie9d22f9f741a63021b8f76906b20c6c2f599885b
Reviewed-on: https://go-review.googlesource.com/c/157218
Reviewed-by: Damien Neil <dneil@google.com>
Most usages of New actually prefer to interact with the reflective view
rather than the native Go type. Thus, change New to return that instead.
This parallels reflect.New, which returns the reflective view
(i.e., reflect.Value) instead of native type (i.e., interface{}).
We make the equivalent change to KnownFields.NewMessage, List.NewMessage,
and Map.NewMessage for consistency.
Since this is a subtle change where the type system will not always
catch the changed type, this change was made by both changing the type
and renaming the function to NewXXX and manually looking at every usage
of the the function to ensure that the usage correctly operates
on either the native Go type or the reflective view of the type.
After the entire codebase was cleaned up, a rename was performed to convert
NewXXX back to New.
Change-Id: I153fef627b4bf0a427e4039ce0aaec52e20c7950
Reviewed-on: https://go-review.googlesource.com/c/157077
Reviewed-by: Damien Neil <dneil@google.com>
The generator currently uses an unintuitive and stateful algorithm
for name generation where it "fixes" name conflicts by appending "_"
to the end of the new name.
PR#657 refactored the generator code and noticed that the above
algorithm was not properly taking into account that a Get method is
generated for parent oneofs, fixing it in the same PR. While this is
more correct, this breaks users (see #780) since it means that the
generation of names can change.
This PR changes the name mangling logic to be as it was previously.
This does mean that some new proto files may be unbuildable,
but that is arguably better than breaking existing proto files
Change-Id: I2e354f4bb5d9c2b562fa2faa9149e949e2d86a0f
Reviewed-on: https://go-review.googlesource.com/c/156877
Reviewed-by: Damien Neil <dneil@google.com>
Drop the protoreflect.ProtoEnum type (containing a single method
returning a protoreflect.Enum) and make generated enum types
directly implement protoreflect.Enum instead.
Messages have a two-level type split (ProtoMessage and Message) to
minimize conflicts between reflection methods and field names. Enums
need no such split, since enums do not have fields and therefore have
no source of conflicts.
Change-Id: I2b6222e9404253e6bfef2217859e1b760ffcd29b
Reviewed-on: https://go-review.googlesource.com/c/156902
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Reviewed-by: Damien Neil <dneil@google.com>
Consider the case:
a.proto publicly imports b.proto
b.proto publicly imports c.proto
Should a.pb.go include symbols defined in c.pb.go?
Historically, it has not. As of #155677, it does. Regardless of which behavior
is preferable, #155677 produces broken code in some common situations: If
a.proto also publicly imports c.proto, we now generate two copies of the
forwarding decls for that file.
Restore the pre-#155677 behavior to avoid this breakage.
Change-Id: I283600b3be19eac2c3b3c14233bb69fa64661581
Reviewed-on: https://go-review.googlesource.com/c/156348
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
New test case demonstrating an import public bug:
a.proto publicly imports b.proto and c.proto
b.proto publicly imports c.proto
a.pb.go includes two copies of symbols in c.pb.go
The problem is that the new implementation of public imports, which
parses the generated code for the import to determine what symbols
are present, doesn't distinguish between symbols defined in a file
and symbols imported from a public import of some other file. This
can then lead to duplicate definitions in cases like the above.
Change-Id: Ia86e9f188d7bae8d9d4afbd2b5db9b64071425c3
Reviewed-on: https://go-review.googlesource.com/c/156347
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Rather than explicitly enumerating the set of symbols to import,
just parse the imported file and extract every exported symbol.
This is possibly a bit more code, but adapts much better to future
expansion.
Change-Id: I4429664f4c068a2a55949d46aefc19865b008a77
Reviewed-on: https://go-review.googlesource.com/c/155677
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Always generate the init func containing the proto.RegisterFile call.
This call used to be in a different init func which was unconditionally
generated. Consolidating the init funcs means that we need to always
generate the single remaining func.
Change-Id: Icbf7d14d018d693dab2824f114c57e4e36384568
Reviewed-on: https://go-review.googlesource.com/c/156197
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
To avoid accidentally emitting the UnmarshalMethod in the unlikely
(but possible) event that a proto4 syntax was added, swich the conditional
to only trigger on the proto2 syntax.
Change-Id: I0c201eace56e9ecc92cd791e45ca5d3b99e2ba86
Reviewed-on: https://go-review.googlesource.com/c/154317
Reviewed-by: Damien Neil <dneil@google.com>
Add fields to the Message and Field builder structs which hold the value
of MessageOptions.map_entry, FieldOptions.packed, and FieldOptions.weak
options. Remove all access to the contents of options messages from the
prototype package.
Change IsPacked to always return false for unpackable field types,
which is consistent with the equivalent C++ API.
This change helps avoid dependency cycles between prototype and the
options messages. (Previously this was resolved by accessing options
with reflection, but just breaking the dependency from prototype to the
options message is cleaner and simpler.)
Change-Id: I756aefe2e04cfa8fea31eaaaa0b5a99d4ac9e851
Reviewed-on: https://go-review.googlesource.com/c/153517
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Remove the Mutable methods from KnownFields, List, and Map, replacing
them with methods which return a new, empty message value without adding
that value to the collection.
The new API is simpler, since it clearly applies only to message values,
and more orthogonal, since it provides a way to create a value without
mutating the collection. This latter point is particularly useful in
map deserialization, where the key may be unknown at the time the value
is deserialized.
Drop the Mutable interface, since it is no longer necessary.
Change-Id: Ic5f3d06a2aa331a5d5cd2b4e670a3dba4a74f77c
Reviewed-on: https://go-review.googlesource.com/c/153278
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
These properties of descriptors are currently missing and makes it impossible
to convert a FileDescriptorProto into one of the structured Go representations
and convert it back to a proto message without loss of information.
Furthermore, ReservedRanges and ReservedNames has semantic importance
to text serialization.
Change-Id: Ic33c30020ad51912b143156b95f47a4fb8da3503
Reviewed-on: https://go-review.googlesource.com/c/153019
Reviewed-by: Damien Neil <dneil@google.com>
Add pseudo-hidden functions to register the concrete Go type used for
the optional types. Also, augment protoc-gen-go to specially generate the
descriptor proto to register these types.
This change does not add validation logic yet to ensure that the correct option
types are passed to the API.
Change-Id: I5decc897e14b4bf570a61cf17b57a066a2a0f9d7
Reviewed-on: https://go-review.googlesource.com/c/153017
Reviewed-by: Damien Neil <dneil@google.com>
The following TODOs were addressed:
* Consistently collect all enums, messages, and extensions in a breadth-first order.
The practical affect of this is that the declaration order in a Go file may change.
This simplifies reflection generation, which relies on consistent ordering.
* Removal of placeholder declarations (e.g., "var _ = proto.Marshal") since
protogen is intelligent about including imports as necessary.
* Always generate a default variable or constant for explicit empty strings.
The practical effect of this is the addition of new declarations in some cases.
However, it simplifies our logic such that it matches the protobuf data model.
* Generate the registration statements in a consistent order.
Change-Id: I627bb72589432bb65d53b50965ea88e5f7983977
Reviewed-on: https://go-review.googlesource.com/c/152778
Reviewed-by: Damien Neil <dneil@google.com>
In CL/152020, we checked in pre-generated versions of descriptor and plugin.
This CL makes it such that they are generated by protoc-gen-go.
We modify protoc-gen-go to avoid reflection support by default
since the binary size increase is still an issue to investigate.
Reflection support is temporarily enabled by setting a special
PROTOC_GEN_GO_ENABLE_REFLECT environment variable.
Reflection support is always enabled for descriptor and plugin.
Furthermore, we change descriptor to depend on the protoapi package
instead of the proto package. The reason we do not switch to protoapi
for all generated protos is because we still depend on v1 proto
for the table-driven InternalMessageInfo type. Dropping it from descriptor
is semantically correct, but does incur slight performance cost.
It does not seem appropriate to drop it for all generated messages.
We could move InternalMessageInfo to protoapi, but the logic behind that
is significant.
Change-Id: I5c3fff7f6eab1a5a2399049d42fa6bf42d4c93f9
Reviewed-on: https://go-review.googlesource.com/c/152547
Reviewed-by: Damien Neil <dneil@google.com>
Implement support in protoc-gen-go for generating messages and enums
that satisfy the v2 protobuf reflection interfaces. Specifically, the following
are added:
* top-level variable representing the file descriptor
* ProtoReflect method on enums (to implement protoV2.Enum)
* ProtoReflect method on messages (to implement protoV2.Message)
The following are not supported yet:
* resolving transitive dependencies for file imports
* Extension descriptors
* Service descriptors
The implementation approach creates a single array for all the message and enum
declarations and references sections of that array to complete dependencies.
Since protobuf declarations can form a graph (a message may depend on itself),
it is difficult to construct a graph as a single literal. One way is to use
placeholder descriptors, but that is not efficient as it requires encoding
the full name of each dependent enum and message and then later resolving it;
thus, both expanding the binary size and also increasing initialization cost.
Instead, we add a prototype.{Enum,Message}.Reference method to obtain a
descriptor reference for the purposes for satisfying dependencies.
As such, nested declarations and dependencies are populated in an init function.
Other changes to support the implementation:
* Added a protoimpl package to expose the MessageType type and also the
MessageTypeOf and EnumTypeOf helper functions.
* Added a protogen.File.GoIdent field to provide a suggested variable name
for the file descriptor.
* Added prototype.{Enum,Message}.Reference that provides a descriptor reference
for the purposes for satisfying cyclic dependencies.
* Added protoreflect.{Syntax,Cardinality,Kind}.GoString to obtain a Go source
identifier that represents the given constant.
Change-Id: I9455764882dee6ad10f251901e7d419091e8bf1d
Reviewed-on: https://go-review.googlesource.com/c/150074
Reviewed-by: Damien Neil <dneil@google.com>
In order to generate descriptor.proto, the generated code would want to depend
on the prototype package to construct the reflection data structures.
However, this is a problem since descriptor itself is one of the dependencies
for prototype. To break this dependency, we do the following:
* Avoid using concrete *descriptorpb.XOptions messages in the public API, and
instead just use protoreflect.ProtoMessage. We do lose some type safety here
as a result.
* Use protobuf reflection to interpret the Options message.
* Split out NewFileFromDescriptorProto into a separate protodesc package since
constructing protobuf reflection from the descriptor proto obviously depends
on the descriptor protos themselves.
As part of this CL, we check in a pre-generated version of descriptor and plugin
that supports protobuf reflection natively and switchover all usages of those
protos to the new definitions. These files were generated by protoc-gen-go
from CL/150074, but hand-modified to remove dependencies on the v1 proto runtime.
Change-Id: I81e03c42eeab480b03764e2fcbe1aae0e058fc57
Reviewed-on: https://go-review.googlesource.com/c/152020
Reviewed-by: Damien Neil <dneil@google.com>
Floating-point defaults of -inf, +inf, and NaN must be generated as
vars rather than consts. Fix the forwarding declaration for public
imports of these vars. (Was "const", is now "var".)
Change-Id: Ic6dc90ab7f88378ba477bff39e047de5f5193c35
Reviewed-on: https://go-review.googlesource.com/c/151757
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Add the scalar package to reduce dependencies on the v1 proto runtime package.
It may very well be the case that these functions should be exposed in the
public API of v2, but that is not a decision we need to make now.
Change-Id: Ifbc6d15311ba5837909ac72af47c630a80a142ef
Reviewed-on: https://go-review.googlesource.com/c/151402
Reviewed-by: Herbie Ong <herbie@google.com>
PR#741 in the v1 repository deprecated this behavior.
Change-Id: Ife48f1d586f178d875b9b3002a88b3336a2cd3b4
Reviewed-on: https://go-review.googlesource.com/c/151401
Reviewed-by: Damien Neil <dneil@google.com>
PR#741 in the v1 repository deprecated this behavior.
Change-Id: Idffa3884d43f9cc5528ce8d9f303676e0e501b67
Reviewed-on: https://go-review.googlesource.com/c/151400
Reviewed-by: Damien Neil <dneil@google.com>
The marshaler, unmarshaler, and sizer functions are unused ever since
the underlying implementation was switched to be table-driven.
Change the function to only return the wrapper structs.
This change:
* enables generated protos to drop dependencies on certain proto types
* reduces the size of generated protos
* simplifies the implementation of oneofs in protoc-gen-go
Updates #708
Change-Id: I845c9009bc0236d1b51d34b014dc3e184303c0f2
Reviewed-on: https://go-review.googlesource.com/c/151357
Reviewed-by: Damien Neil <dneil@google.com>
The GoImportPath.Ident helper creates a GoIdent using the receiver
as the GoImportPath in the GoIdent. This helper helps with the construction
of qualified identifiers.
Example usage:
const protoPackage = protogen.GoImportPath("github.com/golang/protobuf/proto")
protoPackage.Ident("ExtensionRange") // produces "proto.ExtensionRange"
The advantage of this helper is that usage of it looks similar to how
the identifier will eventually be rendered.
This is significantly more readable than the current approach:
protogen.GoIdent{
GoImportPath: protoPackage,
GoName: "ExtensionRange",
}
Change-Id: If7ecd7e60fad12bc491eee0dcb05f8fdebc9c94e
Reviewed-on: https://go-review.googlesource.com/c/150058
Reviewed-by: Damien Neil <dneil@google.com>
The bespoke text-serialization of field descriptors in protoc-gen-go is also
used in the legacy implementation of protobuf reflection to derive a
protoreflect.FieldDescriptor from legacy messages and also to convert to/from
protoreflect.ExtensionDescriptor and protoV1.ExtensionDesc.
Centralize this logic in a single place:
* to avoid reimplementing the same logic in internal/impl
* to keep the marshal and unmarshal logic co-located
Change-Id: I634c5afbb9dc6eda91d6cb6b0e68dbd724cb1ccb
Reviewed-on: https://go-review.googlesource.com/c/146758
Reviewed-by: Herbie Ong <herbie@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
A oneof is represented by a single struct field of interface type.
Pull out the decision of what to name that field into a separate
function.
The function is trivial (return oneof.GoName), but factoring out the
field name like this makes it a bit easier to experiment with changes to
the oneof implementation in the future.
Change-Id: I1114b68c85cb6608852fa1c6bf4103ff58fd5de6
Reviewed-on: https://go-review.googlesource.com/c/146397
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Given:
package foo
extend proto2.bridge.MessageSet {
optional Message message_set_extension = 100;
}
Register the extension as a message set extension and give it the name
"foo.".
We really shouldn't do this in this case; the special-case treatment of
extensions to MessageSet is only for extensions nested in a parent
message. However, this is consistent with the behavior of the v1 generator.
Match that for now.
Change-Id: I919c409605a197904fd3227efc920192d484f431
Reviewed-on: https://go-review.googlesource.com/c/145957
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
When publicly importing a package with extension definitions, generate
forwarding declarations for the "E_..." ExtensionDesc var:
var E_ExtensionField = publicimport.E_ExtensionField
Change-Id: Ifd57c487c3a44f303c2c098a42ea249b219b734f
Reviewed-on: https://go-review.googlesource.com/c/145498
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Don't generate a blank import for unused weak imports.
Full support for weak imports would involve not importing the package at
all. This just avoids generating an import when we don't need one.
Change-Id: I7e8491f415dc8333a2837db5225256b959921be2
Reviewed-on: https://go-review.googlesource.com/c/145497
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Default values for enums are specified by name, not number. An enum
may contain multiple values with different names but the same number.
Representing the default as a protoreflect.Value containing an EnumNumber
can discard information.
Add a method returning the EnumValueDescriptor.
Change-Id: If8beee3f81d41c4f9af45423252603b86949c7a5
Reviewed-on: https://go-review.googlesource.com/c/145158
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
