internal/protobuf: add proto definition extraction
Change-Id: Ia356bcb951e30bcc8030b51cbc5d9949391e84dc
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/1980
Reviewed-by: Marcel van Lohuizen <mpvl@google.com>
diff --git a/internal/protobuf/util.go b/internal/protobuf/util.go
new file mode 100644
index 0000000..e001fa8
--- /dev/null
+++ b/internal/protobuf/util.go
@@ -0,0 +1,89 @@
+// Copyright 2019 CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package protobuf
+
+import (
+ "strings"
+
+ "cuelang.org/go/cue/ast"
+ "cuelang.org/go/cue/token"
+ "github.com/emicklei/proto"
+ "golang.org/x/xerrors"
+)
+
+// failf panics with a marked error that can be intercepted upon returning
+// from parsing.
+func failf(format string, args ...interface{}) {
+ panic(protoError{xerrors.Errorf(format, args...)})
+}
+
+func fail(err error) {
+ panic(protoError{err})
+}
+
+type protoError struct {
+ error
+}
+
+var (
+ newline = token.Pos(token.Newline)
+ newSection = token.Pos(token.NewSection)
+)
+
+func addComments(f ast.Node, i int, doc, inline *proto.Comment) bool {
+ cg := comment(doc, true)
+ if cg != nil && len(cg.List) > 0 && i > 0 {
+ cg.List[0].Slash = newSection
+ }
+ f.AddComment(cg)
+ f.AddComment(comment(inline, false))
+ return doc != nil
+}
+
+func comment(c *proto.Comment, doc bool) *ast.CommentGroup {
+ if c == nil || len(c.Lines) == 0 {
+ return nil
+ }
+ cg := &ast.CommentGroup{}
+ if doc {
+ cg.Doc = true
+ } else {
+ cg.Line = true
+ cg.Position = 10
+ }
+ for _, s := range c.Lines {
+ cg.List = append(cg.List, &ast.Comment{Text: "// " + s})
+ }
+ return cg
+}
+
+func quote(s string) string {
+ if !strings.ContainsAny(s, `"\`) {
+ return s
+ }
+ esc := `\#`
+ for strings.Contains(s, esc) {
+ esc += "#"
+ }
+ return esc[1:] + `"` + s + `"` + esc[1:]
+}
+
+func labelName(s string) string {
+ split := strings.Split(s, "_")
+ for i := 1; i < len(split); i++ {
+ split[i] = strings.Title(split[i])
+ }
+ return strings.Join(split, "")
+}
