Commit Graph

23 Commits

Author SHA1 Message Date
Joe Tsai
cf81e67b53 cmd/protoc-gen-go: use protoapi.CompressGZIP
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>
2019-02-28 22:28:32 +00:00
Damien Neil
71c6603a26 protogen: use full filename in per-file vars
For a file "foo/bar.proto", put the FileDescriptor in "ProtoFile_foo_bar"
rather than "Bar_fileDescriptor".

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

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

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

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

Change-Id: If27d3a0d7b5bf3535aa1607a8579eb057c74d2dc
Reviewed-on: https://go-review.googlesource.com/c/163199
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Reviewed-by: Herbie Ong <herbie@google.com>
2019-02-21 22:37:58 +00:00
Damien Neil
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
5681bb2587 protogen: use _protoFile suffix for file descriptor variable
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>
2019-01-14 20:23:59 +00:00
Joe Tsai
3bc7d6f5cd reflect: switch MessageType.New to return Message
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>
2019-01-09 20:29:29 +00:00
Damien Neil
a8593bae57 reflect/protoreflect: drop the ProtoEnum type
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>
2019-01-09 00:40:35 +00:00
Damien Neil
232ea15589 reflect/prototype: hoist semantic options into builders
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>
2018-12-11 20:25:45 +00:00
Damien Neil
97e7f57dbb reflect/protoreflect: replace Mutable with NewMessage
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>
2018-12-10 21:17:16 +00:00
Joe Tsai
9667c4816d cmd/protoc-gen-go: reduce technical debt
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>
2018-12-07 03:13:48 +00:00
Joe Tsai
b6405bd782 cmd/protoc-gen-go: add support for protobuf reflection
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>
2018-12-05 19:32:12 +00:00
Joe Tsai
d7e97bc71b cmd/protoc-gen-go: generate XXX_OneofWrappers instead of XXX_OneofFuncs
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>
2018-11-27 19:36:27 +00:00
Damien Neil
154da98aa5 cmd/protoc-gen-go: special cases for MessageSet extensions
Add special-case handling for extension fields named
"message_set_extension" that extend a message_set_wire_format message.

Support special cases for a proto1 feature that was superseded by proto2
extensions.

Change-Id: Icbdb711111c66be547bf8d6f37ab3079c320e2a1
Reviewed-on: https://go-review.googlesource.com/136536
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-24 17:25:31 +00:00
Joe Tsai
01ab29648e go.mod: rename google.golang.org/proto as github.com/golang/protobuf/v2
This change was created by running:
	git ls-files | xargs sed -i "s|google.golang.org/proto|github.com/golang/protobuf/v2|g"

This change is *not* an endorsement of "github.com/golang/protobuf/v2" as the
final import path when the v2 API is eventually released as stable.
We continue to reserve the right to make breaking changes as we see fit.

This change enables us to host the v2 API on a repository that is go-gettable
(since go.googlesource.com is not a known host by the "go get" tool;
and google.golang.org/proto was just a stub URL that is not currently served).
Thus, we can start work on a forked version of the v1 API that explores
what it would take to implement v1 in terms of v2 in a backwards compatible way.

Change-Id: Ia3ebc41ac4238af62ee140200d3158b53ac9ec48
Reviewed-on: https://go-review.googlesource.com/136736
Reviewed-by: Damien Neil <dneil@google.com>
2018-09-24 16:11:50 +00:00
Damien Neil
d4803f5a4f cmd/protoc-gen-go: add "packed" encoding tag to fields
Change-Id: I423039d6c9edb50a07781a6e76336ed364f21866
Reviewed-on: https://go-review.googlesource.com/136359
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-20 17:08:44 +00:00
Damien Neil
993c04dcf2 cmd/protoc-gen-go: generate extensions
Generate everything related to extensions: extension descriptors,
XXX_InternalExtensions fields, etc.

Tweak the order in which we generate code for descriptors to ensure
consistent output with the previous protoc-gen-go.

Change Field.ContainingType to Field.ParentMessage, since we need to get
at the parent of both message fields and extensions (and the "containing
type" of an extension field is the extended message, under existing
terminology).

Change-Id: I5d045ca80536436e7c987bca3d8fb8c1e1521e55
Reviewed-on: https://go-review.googlesource.com/136155
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-18 22:49:53 +00:00
Damien Neil
1ec3315873 protoc-gen-go: generate imports consistent with previous protoc-gen-go
Include references to the proto, fmt, and math packages, consistent with
the ones in the previous generator:

	// Reference imports to suppress errors if they are not otherwise used.
	var _ = proto.Marshal
	var _ = fmt.Errorf
	var _ = math.Inf

Sort imports with ast.SortImports to ensure gofmt-compatible output.

Copy the protoc-gen-go/testdata/imports test files from
github.com/golang/protobuf.

Change-Id: I263e2ac750d03596ae9cb23609049d5ef1016205
Reviewed-on: https://go-review.googlesource.com/135361
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-14 22:40:55 +00:00
Damien Neil
ce36f8d1b4 cmd/protoc-gen-go: register messages and map field types
Move generation of the init function that registers all the types in a
file into a single function.

Take some care to generate the registrations in the same order as the
previous protoc-gen-go, to make it easier to catch unintended
differences in output.

For the same reason, adjust the order of generation to generate all
enums before all messages (matches previous behavior).

Change-Id: Ie0d574004d01a16f8d7b10be3882719a3c41676e
Reviewed-on: https://go-review.googlesource.com/135359
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-14 22:26:09 +00:00
Damien Neil
0bd5a38474 cmd/protoc-gen-go: add support for map fields
Generate the proper map[key]value type for map fields.
Include the protobuf_key and protobuf_val field tags.
Do not generate the map entry structs.

Fix an initialization order bug in protogen: While proto files cannot
contain circular dependencies, a single file can contain dependency
cycles. First create types for all the descriptors in a file, then add
in references (currently just field->message and field->enum) in a
second pass.

Change-Id: Ifedfa657d8dbb00413ba493adee1119b19c1b773
Reviewed-on: https://go-review.googlesource.com/135355
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-13 22:20:09 +00:00
Damien Neil
77f82fe6bc cmd/protoc-gen-go: generate getters
Refactor fieldGoType to return the non-pointer type for scalar types
(i.e., "int", not "*int"), and a bool indicating whether the struct
field is a pointer to that type.

Change-Id: Ic80220e92f0b190e41ead847440d57af5c6cc919
Reviewed-on: https://go-review.googlesource.com/135336
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-13 20:51:57 +00:00
Damien Neil
a1c6abc906 cmd/protoc-gen-go: generate common message methods
Generate the standard Reset, String, ProtoMessage, and Descriptor
methods for each message struct.

Generate the table-driven support methods (XXX_Marshal, et al.).

Change-Id: I8a5ed8af1433b481e2458ad534456692d6f74c1f
Reviewed-on: https://go-review.googlesource.com/134996
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-12 22:18:32 +00:00
Damien Neil
d412792d34 cmd/protoc-gen-go: reference proto.ProtoPackageIsVersionX
Include the compile-time assertion that the generated file is compatible
with the proto package it is being compiled against.

Change-Id: Iefa27ee3a99a6669a93303b6674b0033794ba0be
Reviewed-on: https://go-review.googlesource.com/134995
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-12 20:08:45 +00:00
Damien Neil
658051ba78 cmd/protoc-gen-go: generate message fields
This produces exactly the same output as github.com/golang/protobuf.

Change-Id: I01aacc9277c5cb5b4cc295f5ee8af12b4a524781
Reviewed-on: https://go-review.googlesource.com/134955
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-12 18:08:39 +00:00
Damien Neil
46abb57549 cmd/protoc-gen-go: generate enums
This produces exactly the same output (to the best of my ability to
determine) as github.com/golang/protobuf.

Change-Id: Ib60e7a836efb1eb0e5167b30458049ec239e7903
Reviewed-on: https://go-review.googlesource.com/134695
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-11 21:42:46 +00:00