| commit | 70fdd5d140c5bd6b2a9609069ecf679ecf120b25 | [log] [tgz] |
|---|---|---|
| author | Joe Tsai <joetsai@digital-static.net> | Tue Aug 06 01:15:18 2019 -0700 |
| committer | Joe Tsai <joetsai@digital-static.net> | Wed Aug 07 06:00:36 2019 +0000 |
| tree | dd0d26fb5bf79a97f3ca23846e5566bf994f289b | |
| parent | 4a7d633604c0f5edae32f9e33f18096f8ddff982 [diff] |
compiler/protogen, cmd/protoc-gen-go: use alternative comments API
This is a breaking change. High-level protogen API changes:
* remove GeneratedFile.PrintLeadingComments method
* add {Message,Field,Oneof,Enum,EnumValue,Service,Method}.Comments field
* add CommentSet and Comments type
CL/183157 added protoreflect.SourceLocations and it was discovered
that there can actually be duplicate locations for certain paths.
For that reason, we decided not to expose any helper methods
for looking up locations by path since it is unclear which location
to return if multiple matches.
The protogen.GeneratedFile.PrintLeadingComments has a similar dilemma
where it also needs to figure out what to do when duplicates exist.
Previously, it just chooses the first one with comments,
which may not be the right choice in a given context.
Analysis of current PrintLeadingComments usage shows that it is only
ever used (except once) for descriptor declarations.
In the case of descriptor declarations, they are guaranteed by protoc
to have only location.
Thus, we avoid the duplicate location problem by:
* Providing a CommentSet for every descriptor. The CommentSet contains
a set of leading and trailing comments of the Comments type.
* The Comments.String method knows how to interpret the comments
as provided by protoc and format them as // prefixed line comments.
* Values of the Comments type can be passed to the P method.
We drop direct support printing leading comments for non-descriptor locations,
but the exposure of the Comments type makes it easy for users to manually
handle other types of comments themselves.
Change-Id: Id4851456dc4e64d76bd6a30e8ad6137408dfb27a
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/189198
Reviewed-by: Damien Neil <dneil@google.com>
WARNING: This repository is in active development. There are no guarantees about API stability. Breaking changes will occur until a stable release is made and announced.
This repository is for the development of the next major Go implementation of protocol buffers. This library makes breaking API changes relative to the existing Go protobuf library. Of particular note, this API aims to make protobuf reflection a first-class feature of the API and implements the protobuf ecosystem in terms of reflection.
List of relevant design documents:
We appreciate community contributions. See CONTRIBUTING.md.
Issues regarding the new API can be filed at github.com/golang/protobuf. Please use a APIv2: prefix in the title to make it clear that the issue is regarding the new API work.