tree f34175dce495c361d35c38476500ae1fe5fddebf
parent 90fe996bd1b402070b832725468dcee847e91843
author Damien Neil <dneil@google.com> 1540332218 -0700
committer Damien Neil <dneil@google.com> 1540338251 +0000

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>