protogen: include source comments in generated code
Add initial handling of location paths (arrays of integers identifying
an entity in a .proto source file).
Expose path info in protogen; each descriptor has a Path field containing
its location path.
Format comments in protoc-gen-go. This contains one change from
github.com/golang/protobuf: Package comments are now included before the
package statement (but not attached to it) and use // comment syntax
instead of /* */. e.g.,
Before:
package test
/*
This package contains interesting messages.
*/
After:
// This package contains interesting messages.
package test
Change-Id: Ieee13ae77b3584f7562183100554d3df732348aa
Reviewed-on: https://go-review.googlesource.com/133915
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/cmd/protoc-gen-go/main.go b/cmd/protoc-gen-go/main.go
index b9223b0..d330941 100644
--- a/cmd/protoc-gen-go/main.go
+++ b/cmd/protoc-gen-go/main.go
@@ -13,6 +13,7 @@
"encoding/hex"
"fmt"
"strconv"
+ "strings"
"github.com/golang/protobuf/proto"
descpb "github.com/golang/protobuf/protoc-gen-go/descriptor"
@@ -31,22 +32,39 @@
})
}
-func genFile(gen *protogen.Plugin, f *protogen.File) {
+type File struct {
+ *protogen.File
+ locationMap map[string][]*descpb.SourceCodeInfo_Location
+}
+
+func genFile(gen *protogen.Plugin, file *protogen.File) {
+ f := &File{
+ File: file,
+ locationMap: make(map[string][]*descpb.SourceCodeInfo_Location),
+ }
+ for _, loc := range file.Proto.GetSourceCodeInfo().GetLocation() {
+ key := pathKey(loc.Path)
+ f.locationMap[key] = append(f.locationMap[key], loc)
+ }
+
g := gen.NewGeneratedFile(f.GeneratedFilenamePrefix+".pb.go", f.GoImportPath)
g.P("// Code generated by protoc-gen-go. DO NOT EDIT.")
g.P("// source: ", f.Desc.Path())
g.P()
+ const filePackageField = 2 // FileDescriptorProto.package
+ genComment(g, f, []int32{filePackageField})
+ g.P()
g.P("package ", f.GoPackageName)
g.P()
- for _, m := range f.Messages {
- genMessage(gen, g, m)
+ for _, message := range f.Messages {
+ genMessage(gen, g, f, message)
}
genFileDescriptor(gen, g, f)
}
-func genFileDescriptor(gen *protogen.Plugin, g *protogen.GeneratedFile, f *protogen.File) {
+func genFileDescriptor(gen *protogen.Plugin, g *protogen.GeneratedFile, f *File) {
// Determine the name of the var holding the file descriptor:
//
// fileDescriptor_<hash of filename>
@@ -90,12 +108,37 @@
g.P()
}
-func genMessage(gen *protogen.Plugin, g *protogen.GeneratedFile, m *protogen.Message) {
- g.P("type ", m.GoIdent, " struct {")
+func genMessage(gen *protogen.Plugin, g *protogen.GeneratedFile, f *File, message *protogen.Message) {
+ genComment(g, f, message.Path)
+ g.P("type ", message.GoIdent, " struct {")
g.P("}")
g.P()
- for _, nested := range m.Messages {
- genMessage(gen, g, nested)
+ for _, nested := range message.Messages {
+ genMessage(gen, g, f, nested)
}
}
+
+func genComment(g *protogen.GeneratedFile, f *File, path []int32) {
+ for _, loc := range f.locationMap[pathKey(path)] {
+ if loc.LeadingComments == nil {
+ continue
+ }
+ for _, line := range strings.Split(strings.TrimSuffix(loc.GetLeadingComments(), "\n"), "\n") {
+ g.P("//", line)
+ }
+ return
+ }
+}
+
+// pathKey converts a location path to a string suitable for use as a map key.
+func pathKey(path []int32) string {
+ var buf []byte
+ for i, x := range path {
+ if i != 0 {
+ buf = append(buf, ',')
+ }
+ buf = strconv.AppendInt(buf, int64(x), 10)
+ }
+ return string(buf)
+}
diff --git a/cmd/protoc-gen-go/testdata/comments/comments.pb.go b/cmd/protoc-gen-go/testdata/comments/comments.pb.go
new file mode 100644
index 0000000..2b870cd
--- /dev/null
+++ b/cmd/protoc-gen-go/testdata/comments/comments.pb.go
@@ -0,0 +1,45 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// source: comments/comments.proto
+
+// COMMENT: package goproto.protoc.proto2
+
+package proto2
+
+// COMMENT: Message1
+type Message1 struct {
+}
+
+// COMMENT: Message1A
+type Message1_Message1A struct {
+}
+
+// COMMENT: Message1B
+type Message1_Message1B struct {
+}
+
+// COMMENT: Message2
+type Message2 struct {
+}
+
+// COMMENT: Message2A
+type Message2_Message2A struct {
+}
+
+// COMMENT: Message2B
+type Message2_Message2B struct {
+}
+
+func init() { proto.RegisterFile("comments/comments.proto", fileDescriptor_885e8293f1fab554) }
+
+var fileDescriptor_885e8293f1fab554 = []byte{
+ // 136 bytes of a gzipped FileDescriptorProto
+ 0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x12, 0x4f, 0xce, 0xcf, 0xcd,
+ 0x4d, 0xcd, 0x2b, 0x29, 0xd6, 0x87, 0x31, 0xf4, 0x0a, 0x8a, 0xf2, 0x4b, 0xf2, 0x85, 0x44, 0xd3,
+ 0xf3, 0xc1, 0x0c, 0x08, 0x37, 0x19, 0x42, 0x19, 0x29, 0xa9, 0x70, 0x71, 0xf8, 0xa6, 0x16, 0x17,
+ 0x27, 0xa6, 0xa7, 0x1a, 0x4a, 0x71, 0x73, 0x71, 0xc2, 0xd8, 0x8e, 0xc8, 0x1c, 0x27, 0x24, 0x55,
+ 0x46, 0x48, 0x12, 0x46, 0xc8, 0xaa, 0x8c, 0x9c, 0x9c, 0xac, 0xa3, 0x2c, 0xd3, 0xf3, 0xf3, 0xd3,
+ 0x73, 0x52, 0xf5, 0xd2, 0xf3, 0x73, 0x12, 0xf3, 0xd2, 0xf5, 0xf2, 0x8b, 0xd2, 0xf5, 0xc1, 0xf6,
+ 0xe8, 0x27, 0xe7, 0xa6, 0x40, 0x58, 0xc9, 0xba, 0xe9, 0xa9, 0x79, 0xba, 0xe9, 0xf9, 0xfa, 0x25,
+ 0xa9, 0xc5, 0x25, 0x29, 0x89, 0x25, 0x89, 0x10, 0x61, 0x23, 0x40, 0x00, 0x00, 0x00, 0xff, 0xff,
+ 0x32, 0x8f, 0xcd, 0x4f, 0xb9, 0x00, 0x00, 0x00,
+}
diff --git a/cmd/protoc-gen-go/testdata/comments/comments.proto b/cmd/protoc-gen-go/testdata/comments/comments.proto
new file mode 100644
index 0000000..d97c8dc
--- /dev/null
+++ b/cmd/protoc-gen-go/testdata/comments/comments.proto
@@ -0,0 +1,32 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+syntax = "proto2";
+
+// COMMENT: package goproto.protoc.proto2
+package goproto.protoc.proto2;
+
+option go_package = "google.golang.org/proto/cmd/protoc-gen-go/testdata/proto2";
+
+// COMMENT: Message1
+message Message1 {
+ // COMMENT: Message1A
+ message Message1A {
+ }
+
+ // COMMENT: Message1B
+ message Message1B {
+ }
+}
+
+// COMMENT: Message2
+message Message2 {
+ // COMMENT: Message2A
+ message Message2A {
+ }
+
+ // COMMENT: Message2B
+ message Message2B {
+ }
+}
diff --git a/protogen/protogen.go b/protogen/protogen.go
index be5e503..967f000 100644
--- a/protogen/protogen.go
+++ b/protogen/protogen.go
@@ -349,7 +349,7 @@
f.GeneratedFilenamePrefix = prefix
for i, mdescs := 0, desc.Messages(); i < mdescs.Len(); i++ {
- f.Messages = append(f.Messages, newMessage(gen, f, nil, mdescs.Get(i), i))
+ f.Messages = append(f.Messages, newMessage(gen, f, nil, mdescs.Get(i)))
}
return f, nil
}
@@ -380,15 +380,23 @@
GoIdent GoIdent // name of the generated Go type
Messages []*Message // nested message declarations
+ Path []int32 // location path of this message
}
-func newMessage(gen *Plugin, f *File, parent *Message, desc protoreflect.MessageDescriptor, index int) *Message {
+func newMessage(gen *Plugin, f *File, parent *Message, desc protoreflect.MessageDescriptor) *Message {
+ var path []int32
+ if parent != nil {
+ path = pathAppend(parent.Path, messageMessageField, int32(desc.Index()))
+ } else {
+ path = []int32{fileMessageField, int32(desc.Index())}
+ }
m := &Message{
Desc: desc,
GoIdent: newGoIdent(f, desc),
+ Path: path,
}
for i, mdescs := 0, desc.Messages(); i < mdescs.Len(); i++ {
- m.Messages = append(m.Messages, newMessage(gen, f, m, mdescs.Get(i), i))
+ m.Messages = append(m.Messages, newMessage(gen, f, m, mdescs.Get(i)))
}
return m
}
@@ -501,3 +509,34 @@
pathTypeImport pathType = iota
pathTypeSourceRelative
)
+
+// The SourceCodeInfo message describes the location of elements of a parsed
+// .proto file by way of a "path", which is a sequence of integers that
+// describe the route from a FileDescriptorProto to the relevant submessage.
+// The path alternates between a field number of a repeated field, and an index
+// into that repeated field. The constants below define the field numbers that
+// are used.
+//
+// See descriptor.proto for more information about this.
+const (
+ // field numbers in FileDescriptorProto
+ filePackageField = 2 // package
+ fileMessageField = 4 // message_type
+ fileenumField = 5 // enum_type
+ // field numbers in DescriptorProto
+ messageFieldField = 2 // field
+ messageMessageField = 3 // nested_type
+ messageEnumField = 4 // enum_type
+ messageOneofField = 8 // oneof_decl
+ // field numbers in EnumDescriptorProto
+ enumValueField = 2 // value
+)
+
+// pathAppend appends elements to a location path.
+// It does not alias the original path.
+func pathAppend(path []int32, a ...int32) []int32 {
+ var n []int32
+ n = append(n, path...)
+ n = append(n, a...)
+ return n
+}
