16 Commits

Author SHA1 Message Date
Joe Tsai
a804450cf6 all: fix stale comments
Change-Id: I4bfef75bc74c8d876a3926635bea12bbbaf4993e
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185238
Reviewed-by: Damien Neil <dneil@google.com>
2019-07-08 18:33:38 +00:00
Joe Tsai
32e8a52cbf internal/impl: fix race in aberrant message logic
Previously, when aberrantLoadMessageDesc returned it was guaranteed
to have initialized the current message through the use of the done signal.
However, this does not guarantee that the descriptor for a cylic reference
has also finished initialization.

Rather than add more complicated logic to wait until all cyclic references
have finished initializing, just add a global lock for the entire
aberrantLoadMessageDesc function.

This slows down performance, but is easier to reason about.

Change-Id: I4cdae8b955f71ee40fa6979f5a8d548d9749042c
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/184657
Reviewed-by: Damien Neil <dneil@google.com>
2019-07-02 18:39:06 +00:00
Joe Tsai
28e61ba70b internal/impl: drop XXX_MessageName aberrant support
The aberrant support logic only has access to the Go type
information, and not a concrete value. However, the XXX_MessageName
method exists on some hacky dynamic proto implementations where
it is only valid to call on a concrete value, not just newly created
instance of the given type.

However, from the perspective of the support logic, it is impossible
to distinguish between dynamic messages and hand-crafted custom messages.
Thus, just drop support for XXX_MessageName. We won't get the full name
of the message right, but oh well, what can we do.

Change-Id: Icc272861e11a355639fb82a991ca2854a9edc0c7
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/184557
Reviewed-by: Damien Neil <dneil@google.com>
2019-07-01 21:51:21 +00:00
Joe Tsai
851185dae3 internal/impl: support aberrant enums and messages
Aberrant messages are hand-crafted messages that happen to work because
they use the same struct tags that generated code emits.
This happens to work in v1, but is unspecified behavior and entirely outside
the compatibility promise.

Support for this was added early on in the history of the v2 implementation,
but entirely untested. It was removed in CL/182360 to reduce the
technical debt of the legacy implementation. Unfortunately, sufficient number
of targets do rely on this aberrant support, so it is being added back.

The logic being added is essentially the same thing as the previous logic,
but ported to use internal/filedesc instead of the now deleted
internal/prototype package.

Change-Id: Ib5cab3e90480825b9615db358044ce05a14b05bd
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/184517
Reviewed-by: Damien Neil <dneil@google.com>
2019-07-01 21:18:15 +00:00
Joe Tsai
d888139e7b internal/filedesc, internal/filetype: initial commit
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>
2019-06-20 02:06:11 +00:00
Joe Tsai
21ade498bd internal/impl: move legacy files into impl
The internal/legacy package was originally separated out from internal/impl
to avoid a cyclic dependency on descriptor proto. However, the dependency
that legacy has on descriptor has long been dropped such that we can
now merge the two packages together again.

All legacy related logic are in a file with a legacy prefix.

Change-Id: I2424fc0f50721696ad06fa7cebb9bdd0babea13c
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/178542
Reviewed-by: Damien Neil <dneil@google.com>
2019-05-22 19:40:32 +00:00
Joe Tsai
08e0030032 internal/legacy: extract legacy support out from the impl package
The impl package currently supports wrapping legacy v1 enums and messages
so that they implement the v2 reflective APIs. This functionality is necessary
for v1 and v2 to interoperate. However, the existence of this functionality
presents several problems:
	* A significant portion of the complexity in impl is for legacy wrapping.
	* This complexity is linked into a Go binary even if all the other messages
	in the binary natively support v2 reflection.
	* It presents a cyclic dependency when trying to generate descriptor proto.

Suppose you are generating descriptor.proto. The generated code would want to
depend on the impl package because impl is the runtime implementation for
protobuf messages. However, impl currently depends depends on descriptor in
order to wrap legacy enum and messages since it needs the ability to dynamically
create new protobuf descriptor types. In the case of descriptor.proto, it would
presumably be generated with native reflection support, so the legacy wrapping
logic is unneccessary.

To break the dependency of impl on descriptor, we move the legacy support logic
to a different package and instead add hooks in impl so that legacy support could
be dynamically registered at runtime. This is dependency injection.

Change-Id: I01a582908ed5629993f6699e9bf2f4bee93857a4
Reviewed-on: https://go-review.googlesource.com/c/151877
Reviewed-by: Herbie Ong <herbie@google.com>
2018-11-30 23:16:16 +00:00
Joe Tsai
ba0ef9a571 internal/value: rename the Unwrap method as ProtoUnwrap
Add a Proto prefix before the Unwrap method to reduce the probability that
it would ever conflict with a method of the same name that a
custom implementation of Enum, Message, List, or Map may have.

Change-Id: I628bf8335583f2747ab4589f3e6ff82e4501ce98
Reviewed-on: https://go-review.googlesource.com/c/151817
Reviewed-by: Herbie Ong <herbie@google.com>
2018-11-30 01:23:40 +00:00
Joe Tsai
25cc69d405 internal/impl: fix legacy logic to know about the new XXX_OneofWrappers method
The XXX_OneofWrappers method is a simplified way to obtain the wrapper structs
compared the previous XXX_OneofFuncs method which returned far more information
that was strictly necessary.

Change-Id: I2670506a2a8f7e8e724846b8c4083e7995371007
Reviewed-on: https://go-review.googlesource.com/c/151679
Reviewed-by: Herbie Ong <herbie@google.com>
2018-11-29 08:04:36 +00:00
Joe Tsai
009e067ed8 internal/scalar: add scalar package for primitive wrappers
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>
2018-11-28 07:06:11 +00:00
Joe Tsai
f0c01e459b internal/impl: support legacy extension fields
Implement support for extension fields for messages that use the v1
data structures for extensions. The legacyExtensionFields type wraps a
v1 map to implement the v2 protoreflect.KnownFields interface.

Working on this change revealed a bug in the dynamic construction of
message types for protobuf messages that had cyclic dependencies (e.g.,
message Foo has a sub-field of message Bar, and Bar has a sub-field of Foo).
In such a situation, a deadlock occurs because initialization code depends on
the very initialization code that is currently running. To break these cycles,
we make some systematic changes listed in the following paragraphs.
Generally speaking, we separate the logic for construction and wrapping,
where constuction does not recursively rely on dependencies,
while wrapping may recursively inspect dependencies.

Promote the MessageType.MessageOf method as a standalone MessageOf function
that dynamically finds the proper *MessageType to use. We make it such that
MessageType only supports two forms of messages types:
* Those that fully implement the v2 API.
* Those that do not implement the v2 API at all.
This removes support for the hybrid form that was exploited by message_test.go

In impl/message_test.go, switch each message to look more like how future
generated messages will look like. This is done in reaction to the fact that
MessageType.MessageOf no longer exists.

In value/{map,vector}.go, fix Unwrap to return a pointer since the underlying
reflect.Value is addressable reference value, not a pointer value.

In value/convert.go, split the logic apart so that obtaining a v2 type and
wrapping a type as v2 are distinct operations. Wrapping requires further
initialization than simply creating the initial message type, and calling it
during initial construction would lead to a deadlock.

In protoreflect/go_type.go, we switch back to a lazy initialization of GoType
to avoid a deadlock since the user-provided fn may rely on the fact that
prototype.GoMessage returned.

Change-Id: I5dea00e36fe1a9899bd2ac0aed2c8e51d5d87420
Reviewed-on: https://go-review.googlesource.com/c/148826
Reviewed-by: Herbie Ong <herbie@google.com>
2018-11-14 18:37:45 +00:00
Joe Tsai
6f9095c675 internal/value: expose Converter.{MessageType,EnumType}
Rather than having the Converter carry a NewMessage method, have the struct
simply expose the MessageType or EnumType since they carry more information
and are retrieved anyways as part of the functionality of NewConverter.
While changing Converter, export the fields and remove all the methods.
Also, add an IsLegacy boolean, which is useful for the later implementation
of the extension fields.

Add a wrapLegacyEnum function which is used to wrap v1 enums as v2 enums.
We use this functionality in NewLegacyConverter to detrive the EnumType.
Additionally, modify wrapLegacyMessage to return a protoreflect.ProtoMessage
to be consistent with wrapLegacyEnum which must return a protoreflect.ProtoEnum.

Change-Id: Idc8989d07e4895d30de4ebc22c9ffa7357815cad
Reviewed-on: https://go-review.googlesource.com/c/148827
Reviewed-by: Herbie Ong <herbie@google.com>
2018-11-12 22:59:43 +00:00
Joe Tsai
ce6edd3c71 internal/impl: support message and enum fields
Dynamically generate functions for handling message and enum fields,
regardless of whether they are of the v1 or v2 forms.

If a v1 message is encountered, it is automatically wrapped such that it
implements the v2 interface.

Change-Id: I457bc5286892e8fc00a61da7062dd33058daafd5
Reviewed-on: https://go-review.googlesource.com/c/143837
Reviewed-by: Damien Neil <dneil@google.com>
2018-11-05 22:25:52 +00:00
Joe Tsai
05828dba44 internal/encoding/tag: centralize logic for protobuf struct tag serialization
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>
2018-11-05 20:12:56 +00:00
Damien Neil
204f1c0ad8 reflect/protoreflect: add Descriptor.Options method
Add a method to fetch descriptor options. Since options are proto
messages (e.g., google.protobuf.FieldOptions), and proto message
packages depend on the protoreflect package, returning the actual option
type would cause a dependency cycle. Instead, we return an interface
value which can be type asserted to the appropriate concrete type.

Add options support to the prototype package.

Some of the prototype constructors included fields (such as
Field.IsPacked) which represent information from the options
(such as google.protobuf.FieldOptions.packed). To avoid confusion about
the canonical source of information, drop these fields in favor of the
options.

Drop the unimplemented Descriptor.DescriptorOptionsProto.

Change-Id: I66579b6a7d10d99eb6977402a247306a78913e74
Reviewed-on: https://go-review.googlesource.com/c/144277
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-10-23 23:44:11 +00:00
Joe Tsai
90fe996bd1 internal/impl: derive descriptors for legacy enums and messages
In order for the v2 rollout to be as seamless as possible, we need to support
the situation where a v2 message depends on some other generated v1 message that
may be stale and does not support the v2 API. In such a situation, there needs
to be some way to wrap a legacy message or enum in such a way that it satisfies
the v2 API.

This wrapping is comprised of two parts:
1) Deriving an enum or message descriptor
2) Providing an reflection implementation for messages

This CL addresses part 1 (while part 2 has already been partially implemented,
since the implementation applies to both v1 and v2).

To derive the enum and message descriptor we rely on a mixture of parsing the
raw descriptor proto and also introspection on the fields in the message.
Methods for obtaining the raw descriptor protos were added in February, 2016,
and so has not always been available. For that reason, we attempt to derive
as much information from the Go type as possible.

As part of this change, we modify prototype to be able to create multiple
standalone messages as a set. This is needed since cyclic dependencies is allowed
between messages within a single proto file.

Change-Id: I71aaf5f977faf9fba03c370b1ee17b3758ce60a6
Reviewed-on: https://go-review.googlesource.com/c/143539
Reviewed-by: Damien Neil <dneil@google.com>
2018-10-22 17:18:39 +00:00