46 Commits

Author SHA1 Message Date
Joe Tsai
55f18259ef internal/testprotos/legacy: rename and regenerate
Avoid dots and dashes in the directory to avoid issues on
build systems that cannot support them well.

Change-Id: I7ea5e6ce0b16c7158c7e53bcf5c3c1a334fe4718
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/214342
Reviewed-by: Damien Neil <dneil@google.com>
2020-01-12 08:13:18 +00:00
Damien Neil
c826885a2a reflect/protoregistry: add (*Types).Register{Message,Enum,Extension}
Add type-safe methods to register message, enum, and extension types.
Deprecate the NewTypes function and the (*Types).Register method.

Add (*File).RegisterFile and deprecate the NewFiles function and
the (*File).Register method.

Updates golang/protobuf#963

Change-Id: Ie89e77526e0874539e9bd929ca0ba8d758e65a6e
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/199898
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-10-31 16:23:42 +00:00
Damien Neil
3b65992c65 all: remove {Enum,Message,Extension}Type.GoType methods
These methods are difficult or impossible to use correctly; types
created by the dynamicpb package, for example, all have the same GoType.

Fixes golang/protobuf#938

Change-Id: I33d4ef381579ff18569b11df501d0ba7f38a6b5c
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/199060
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-10-07 21:08:26 +00:00
Joe Tsai
fd4c605bfb internal: simplify ExtensionInfo initialization
This CL:
* Make the meaning of impl/ExtensionInfo.goType consistent. Before,
it was sometimes a T and other times a []T depending on the current
state of initialization. Change it so that it is the constructor's
responsibility to pass in a []T if it is repeated.
* Make internal/filetype responsible for constructing a []T for
repeated extension fields.
* Makes filedesc/Extension.Cardinality one of the eagerly initialized
pieces of information since it is useful to internal/filetype.
* Unify ExtensionInfo.desc and ExtensionInfo.tdesc.ExtensionField,
which held the same information.
* Remove the internal implementation for impl.X.ExtensionDescFromType
since we are dropping support for this from v1.

Change-Id: Ie95c4de66cd674c1d886da4f63b133b7d763c7ef
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/195777
Reviewed-by: Damien Neil <dneil@google.com>
2019-09-16 22:06:06 +00:00
Joe Tsai
ea5ada15be internal/impl: support legacy message names
This change:
* Adds aberrant support for the undocumented XXX_MessageName method.
* Adds LegacyMessageTypeOf so that v1 registration can suggest a
fullname to use with a legacy message with no Descriptor support.

Change-Id: I0265bd3cf67f4d4815358148f5817695c1122dc8
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/193518
Reviewed-by: Damien Neil <dneil@google.com>
2019-09-05 17:56:38 +00:00
Joe Tsai
6663f3a630 internal/impl: add ProtoMessageV1Of and ProtoMessageV2Of
These functions are used by v1 code to switch between
protoV1.Message and protoV2.Message.
Wrappers over them may be exposed in a hypothetical protoadapt package.

Change-Id: Ib5265420e34e9888b540307962c70189625d663c
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/193180
Reviewed-by: Damien Neil <dneil@google.com>
2019-09-03 23:27:40 +00:00
Damien Neil
293dc761cb internal/impl: change Go representation of extension lists to []T
Change-Id: Iebcefe0330c8f858c7735f9362abfd87043ee39d
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/192458
Reviewed-by: Joe Tsai <joetsai@google.com>
2019-09-03 21:19:03 +00:00
Damien Neil
79bfdbe45b all: rename ExtensionType Descriptor method to TypeDescriptor (1/2)
Descriptor methods generally return a Descriptor with no Go type
information. ExtensionType's Descriptor is an exception, returning an
ExtensionTypeDescriptor containing both the proto descriptor and a
reference back to the ExtensionType. The pure descriptor is accessed
by xt.Descriptor().Descriptor().

Rename ExtensionType's Descriptor method to TypeDescriptor to make it
clear that it behaves a bit differently.

Change 1/2: Add the TypeDescriptor method and deprecate Descriptor.

Change-Id: I1806095044d35a474d60f94d2a28bdf528f12238
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/192139
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-08-28 18:34:29 +00:00
Damien Neil
f1e905b042 all: unify protoV1.ExtensionDesc and proto.ExtensionType
Change protoV1.ExtensionDesc to directly implement ExtensionType
rather than delegating to one.

Unify the previous types protoiface.ExtensionDescV1 and
filetype.Extension in impl.ExtensionInfo. The protoV1.ExtensionDesc
type becomes an alias to ExtensionInfo.

This gives us:

  - Just one implementation of ExtensionType.
  - Generated foopb.E_Ext vars are canonical ExtensionTypes.
  - Generated foopb.E_Ext vars are also v1.ExtensionDescs for backwards
    compatibility.
  - Conversion between legacy and modern representations happens
    transparently when lazily initializing an ExtensionInfo.

Overall, a simplification for users of generated code, since they can
mostly ignore the ExtensionDesc/ExtentionType distinction and use the
same value in either the old or new API.

This is change 3/5 in a series of commits changing protoV1.ExtensionDesc
to directly implement protoreflect.ExtensionType.

1. [v2] Add protoimpl.ExtensionInfo as an alias for
   protoiface.ExtensionDescV1.

2. [v1] Update references to protoimpl.ExtensionInfo to use
   protoiface.ExtensionInfo.

3. [v2] Create protoimpl.ExtensionInfo (an alias to a new type in
   the impl package) and remove protoiface.ExtensionDescV1.

4. [v1] Remove unneeded explicit conversions between ExtensionDesc and
   ExtensionType (since the former now directly implements the latter).

5. [v2] Remove stub conversion functions.

Change-Id: I96ee890541ec11b2412e1a72c9d7b96e4d7f66b4
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/189563
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-08-20 21:32:57 +00:00
Damien Neil
16163b4f67 all: drop reflect/prototype package
Remove the remaining uses of the prototype package.

The most significant change is to impl.MessageInfo, which now directly
implements the MessageType interface. This involves two notable changes
to exported fields of MessageInfo:

  - PBType is now Desc.
  - GoType is now GoReflectType. (Name changed to avoid a conflict with
    the GoType method of the MessageType interface.)

Fixes golang/protobuf#911

Change-Id: Ie2aa4766d6887ceaa9cf06b1f109aa6e6e2a208f
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/189340
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-08-09 19:06:30 +00:00
Damien Neil
92f76189a3 all: refactor extensions, add proto.GetExtension etc.
Change protoiface.ExtensionDescV1 to implement protoreflect.ExtensionType.

ExtensionDescV1's Name field conflicts with the Descriptor Name method,
so change the protoreflect.{Message,Enum,Extension}Type types to no
longer implement the corresponding Descriptor interface. This also leads
to a clearer distinction between the two types.

Introduce a protoreflect.ExtensionTypeDescriptor type which bridges
between ExtensionType and ExtensionDescriptor.

Add extension accessor functions to the proto package:
proto.{Has,Clear,Get,Set}Extension. These functions take a
protoreflect.ExtensionType parameter, which allows writing the
same function call using either the old or new API:

  proto.GetExtension(message, somepb.E_ExtensionFoo)

Fixes golang/protobuf#908

Change-Id: Ibc65d12a46666297849114fd3aefbc4a597d9f08
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/189199
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-08-08 18:20:51 +00:00
Damien Neil
d4f0800c42 all: make handling of zero-value composites more consistent
We occasionally need to work with immutable, empty lists, maps, and
messages. Notably, Message.Get on an empty repeated field will return a
"frozen" empty value.

Move handling of these immutable, zero-length composites into Converter,
to unify the behavior of regular and extension fields.

Add a Zero method to Converter, MessageType, and ExtensionType, to
provide a consistent way to get an empty, frozen value of a composite
type. Adding this method to the public {Message,Extension}Type
interfaces does increase our API surface, but lets us (for example)
cleanly represent an empty map as a nil map rather than a non-nil
one wrapped in a frozenMap type.

Drop the frozen{List,Map,Message} types as no longer necessary.
(These types did have support for creating a read-only view of a
non-empty value, but we are not currently using that feature.)

Change-Id: Ia76f149d591da07b40ce75b7404a7ab8a60cb9d8
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/189339
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-08-08 18:20:25 +00:00
Damien Neil
954bd92c19 all: refactor Converter
A Converter converts between reflect.Values and protoreflect.Values.
The existing usage of Converter is somewhat confusing: The
internal/value package creates Converters for scalar types only, the
internal/impl package creates Converters for legacy messages and enums,
and the reflect/prototype package creates Converters for repeated fields.

Change the Converter type to an interface. The constructor for
Converter takes a FieldDescriptor and reflect.Type, and directly
handles conversions for all field types: Scalars, lists, maps, and
legacy types.

Move Converter into the internal/impl package, since that package
contains the necessary support for dealing with legacy messages and
enums. Drop the internal/value package.

Replace two uses of prototype.Extension with more focused
implementations, since the implementation is trivial with the
refactored Converter. Drop prototype.Extension for the moment since
it is now unused.

Change-Id: If0c570fefac002cc5925b3d56281b6eb17e90d5f
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/187857
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-08-05 22:33:14 +00:00
Joe Tsai
d421150c3b reflect/protoreflect: add Enum.Type and Message.Type
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>
2019-07-12 23:43:21 +00:00
Damien Neil
a8a2cea3e7 proto: move T->*T wrappers from internal/scalar to proto
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>
2019-07-12 17:35:01 +00:00
Damien Neil
a9940822d4 all: remove protoreflect.Message.Len
Len looks like it should be O(1), but the need to check for
non-zero-length repeated fields makes it at minimum O(n) where n is
the number of repeated fields. In practice, it's O(n) where n is the
number of fields altogether.

The Len function is not especially useful, easily duplicated with Range
and a counter, and can be surprisingly inefficient. Drop it.

Change-Id: I24b27433217e131e842bd18dd58475bcdf62ef97
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/183678
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-06-25 21:59:46 +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
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
89d49632e5 internal/impl: abstract away ExtensionDescV1 as the underlying descriptor
Add ExtensionField.{SetType,GetType} to hide the fact that the underlying
descriptor is actually an ExtensionDescV1.

Change-Id: I1d0595484ced0a88d2df0852a732fdf0fe9aa232
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/180538
Reviewed-by: Damien Neil <dneil@google.com>
2019-06-05 19:53:14 +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
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
0fc49f8225 reflect/protoreflect: add Descriptor specific methods
Added methods:
	Enum.Descriptor
	Message.Descriptor
	EnumType.Descriptor
	MessageType.Descriptor
	ExtensionType.Descriptor
	Message.New

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

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

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

Change-Id: I7fefde1673bbd40bfdac489aca05cec9a6c98eb1
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/174918
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Herbie Ong <herbie@google.com>
2019-05-13 19:34:41 +00:00
Joe Tsai
00a323deed internal/impl: use XXX_unrecognized exclusively for unknown fields
The protobuf data model makes no distinction between unknown fields
that are within the extension field ranges or not. Now that we eagerly
unmarshal extensions, there is even less need for storing unknown
fields in the extension map. Instead, use the XXX_unrecognized field
exclusively for this purpose.

Change-Id: I673a7d6259fe9fdbdc295bcfa8252ef4da415343
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/175579
Reviewed-by: Damien Neil <dneil@google.com>
2019-05-09 01:26:50 +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
00e50dc9c1 runtime/protoimpl: remove ExtensionFieldsV1
This is no longer directly used by v1.

Change-Id: I14a283dd2d1572d50ebd82fdf55f7d86bfacc272
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/172438
Reviewed-by: Damien Neil <dneil@google.com>
2019-04-16 23:53:07 +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
990b9f5919 internal/prototype: move from reflect/prototype
The prototype package was initially used by generated reflection support,
but has now been replaced by internal/fileinit.
Eventually, this functionality should be deleted and re-written in terms
of other components in the repo.

Usages that prototype currently provides (but should be moved) are:
* Constructing standalone messages and enums, which is behavior we should
provide in reflect/protodesc. The google.protobuf.{Enum,Type} are well-known
proto messages designed for this purpose.
* Constructing placeholder files, enums, and messages.
* Consructing protoreflect.{Message,Enum,Extension}Types, which are protobuf
descriptors with associated Go type information.

Change-Id: Id7dbefff952682781b439aa555508c59b2629f9e
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/167383
Reviewed-by: Damien Neil <dneil@google.com>
2019-03-13 20:17:00 +00:00
Damien Neil
8012b444ee internal/fileinit: generate reflect data structures from raw descriptors
This CL takes a significantly different approach to generating support
for protobuf reflection. The previous approach involved generating a
large number of Go literals to represent the reflection information.
While that approach was correct, it resulted in too much binary bloat.

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

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

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

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

Change-Id: I6090f023f2e1b6afaf62bd3ae883566242e30715
Reviewed-on: https://go-review.googlesource.com/c/158539
Reviewed-by: Herbie Ong <herbie@google.com>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2019-01-30 01:33:46 +00:00
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
f18ab539ab all: make use of the protoapi package in v1
The new v1 protoapi package enables:
* Referencing types in the protoapi package instead of protoV1, which further
reduces the number of situations where we need to depend on protoV1.
This is for the goal of eventually breaking all cases where the v2 implementation
relies on v1, so that in the near future, proto v1 can rely on proto v2 instead.
* Removes the need for legacy_extension_hack.go since that functionality has now
been exported into the protoapi package.

Change-Id: If71002d9ec711bfabfe494636829df9abf19e23e
Reviewed-on: https://go-review.googlesource.com/c/151403
Reviewed-by: Herbie Ong <herbie@google.com>
2018-11-29 22:46:29 +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
f6d4a4215f reflect/protoreflect: clarify Get semantics on unpopulated fields
Clearly specify that Get on an unpopulated field:
* returns the default value for scalars
* returns a mutable (but empty) List for repeated fields
* returns a mutable (but empty) Map for map fields
* returns an invalid value for message fields

The difference in semantics between List+Maps and Messages is because
protobuf semantics provide no distinction between an unpopulated and empty list
or map. On the other hand, there is a semantic difference between an unpopulated
message and an empty message.

Default values for scalars is trivial to implement with FieldDescriptor.Default.

A mutable, but empty List and Map is easy to implement for known fields since
known fields are generated as a slice or map field in a struct.
Since struct fields are addressable, the implementation can just return a
reference to the slice or map.

Repeated, extension fields are a little more tricky since extension fields
are implemented under the hood as a map[FieldNumber]Extension.
Rather than allocating an empty list in KnownFields.Get upon first retrieval
(which presents a race), delegate the work to ExtensionFieldTypes.Register,
which must occur before any Get operation. Register is not a concurrent-safe
operation, so that is an excellent time to initilize empty lists.
The implementation of extensions will need to be careful that Clear on a repeated
field simply truncates it zero instead of deleting the object.

For unpopulated messages, we return an invalid value, instead of the prior
behavior of returning a typed nil-pointer to the Go type for the message.
The approach is problematic because it assumes that
1) all messages are always implemented on a pointer reciever
2) a typed nil-pointer is an appropriate "read-only, but empty" message
These assumptions are not true of all message types (e.g., dynamic messages).

Change-Id: Ie96e6744c890308d9de738b6cf01d3b19e7e7c6a
Reviewed-on: https://go-review.googlesource.com/c/150319
Reviewed-by: Damien Neil <dneil@google.com>
2018-11-27 19:13:59 +00:00
Joe Tsai
87b955ba7f internal/impl: add extensive tests for enum and messages
Add more extensive tests to ensure that the reflective API works for both
enums and messages. We tests the situation where a v2 message has dependencies
on v1 messages and vice versa.

Change-Id: Ib85d465711728ae13743bea700b678d9dda5e85c
Reviewed-on: https://go-review.googlesource.com/c/149758
Reviewed-by: Herbie Ong <herbie@google.com>
2018-11-15 23:10:55 +00:00
Joe Tsai
4b7aff630a all: rename Vector as List
The terminology Vector does not occur in protobuf documentation at all,
so we should rename the Go use of the term to something more recognizable.
As such, all instances that match the regexp "[Vv]ect(or)?" were replaced.

The C++ documentation uses the term "Repeated", which is a reasonable name.
However, the term became overloaded in 2014, when maps were added as a feature
and implementated under the hood as repeated fields. This is confusing as it
means "repeated" could either refer to repeated fields proper (i.e., explicitly
marked with the "repeated" label in the proto file) or map fields. In the case
of the C++ reflective API, this is not a problem since repeated fields proper
and map fields are interacted with through the same RepeatedField type.

In Go, we do not use a single type to handle both types of repeated fields:
1) We are coming up with the Go protobuf reflection API for the first time
and so do not need to piggy-back on the repeated fields API to remain backwards
compatible since no former usages of Go protobuf reflection exists.
2) Map fields are commonly represented in Go as the Go map type, which do not
preserve ordering information. As such it is fundamentally impossible to present
an unordered map as a consistently ordered list. Thus, Go needs two different
interfaces for lists and maps.

Given the above situation, "Repeated" is not a great term to use since it
refers to two different things (when we only want one of the meanings).
To distinguish between the two, we'll use the terms "List" and "Map" instead.
There is some precedence for the term "List" in the protobuf codebase
(e.g., "getRepeatedInt32List").

Change-Id: Iddcdb6b78e1e60c14fa4ca213c15f45e214b967b
Reviewed-on: https://go-review.googlesource.com/c/149657
Reviewed-by: Damien Neil <dneil@google.com>
2018-11-14 23:03:53 +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
ea11813c05 internal/testprotos/legacy: initial commit
Add a corpus of generated protobuf messages generated at specific versions
of protoc-gen-go to ensure that we continue to support for generated messages
that have may never be updated.

Change-Id: I04a1b74306f471d7c99f5daf52399a5bd9adcbbc
Reviewed-on: https://go-review.googlesource.com/c/148831
Reviewed-by: Herbie Ong <herbie@google.com>
2018-11-13 22:37:52 +00:00
Joe Tsai
95b0290ea8 internal/impl: support legacy unknown extension fields
The unknown fields in legacy messages is split across the XXX_unrecognized
field and also the XXX_InternalExtensions field. Implement support for
wrapping both fields and presenting it as if it were a unified set of
unknown fields.

Change-Id: If274fae2b48962520edd8a640080b6eced747684
Reviewed-on: https://go-review.googlesource.com/c/146517
Reviewed-by: Damien Neil <dneil@google.com>
2018-11-01 18:28:27 +00:00
Joe Tsai
2d5a169f75 internal/impl: use linked-list for unknown field ordering
Unknown fields follow a policy where the latest field takes precedence when
it comes to the ordering. However, the current implementation is incorrect
as it uses a slice and simply swaps the current entry with the last entry.
While this ensures that the latest field seen remains last, it does not ensure
that the swapped out entry is second-to-last.

To provide the desired behavior, a linked-list is used.
For simplicity, we use the list package in the standard library even if it
is neither the most performant nor type safe.

Change-Id: I675145c61f6b5b624ed9e94bbe2251b5a71e2c48
Reviewed-on: https://go-review.googlesource.com/c/145241
Reviewed-by: Damien Neil <dneil@google.com>
2018-10-31 18:39:54 +00:00
Joe Tsai
e2afdc27e7 internal/impl: support legacy unknown fields
Add wrapper data structures to get legacy XXX_unrecognized fields to support
the new protoreflect.UnknownFields interface. This is a challenge since the
field is a []byte, which does not give us much flexibility to work with
in terms of choice of data structures.

This implementation is relatively naive where every operation is O(n) since
it needs to strip through the entire []byte each time. The Range operation
operates slightly differently from ranging over Go maps since it presents a
stale version of RawFields should a mutation occur while ranging.
This distinction is unlikely to affect anyone in practice.

Change-Id: Ib3247cb827f9a0dd6c2192cd59830dca5eef8257
Reviewed-on: https://go-review.googlesource.com/c/144697
Reviewed-by: Damien Neil <dneil@google.com>
2018-10-26 19:55:21 +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