cmd/protoc-gen-go: don't chain public imports
Consider the case:
a.proto publicly imports b.proto
b.proto publicly imports c.proto
Should a.pb.go include symbols defined in c.pb.go?
Historically, it has not. As of #155677, it does. Regardless of which behavior
is preferable, #155677 produces broken code in some common situations: If
a.proto also publicly imports c.proto, we now generate two copies of the
forwarding decls for that file.
Restore the pre-#155677 behavior to avoid this breakage.
Change-Id: I283600b3be19eac2c3b3c14233bb69fa64661581
Reviewed-on: https://go-review.googlesource.com/c/156348
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/cmd/protoc-gen-go/internal_gengo/main.go b/cmd/protoc-gen-go/internal_gengo/main.go
index 5e6b7b7..46d26a2 100644
--- a/cmd/protoc-gen-go/internal_gengo/main.go
+++ b/cmd/protoc-gen-go/internal_gengo/main.go
@@ -200,7 +200,7 @@
gen.Error(err)
return
}
- genForward := func(tok token.Token, name string) {
+ genForward := func(tok token.Token, name string, expr ast.Expr) {
// Don't import unexported symbols.
r, _ := utf8.DecodeRuneInString(name)
if !unicode.IsUpper(r) {
@@ -210,6 +210,13 @@
if name == impFile.GoDescriptorIdent.GoName {
return
}
+ // Don't import decls referencing a symbol defined in another package.
+ // i.e., don't import decls which are themselves public imports:
+ //
+ // type T = somepackage.T
+ if _, ok := expr.(*ast.SelectorExpr); ok {
+ return
+ }
g.P(tok, " ", name, " = ", impFile.GoImportPath.Ident(name))
}
g.P("// Symbols defined in public import of ", imp.Path())
@@ -220,10 +227,14 @@
for _, spec := range decl.Specs {
switch spec := spec.(type) {
case *ast.TypeSpec:
- genForward(decl.Tok, spec.Name.Name)
+ genForward(decl.Tok, spec.Name.Name, spec.Type)
case *ast.ValueSpec:
- for _, name := range spec.Names {
- genForward(decl.Tok, name.Name)
+ for i, name := range spec.Names {
+ var expr ast.Expr
+ if i < len(spec.Values) {
+ expr = spec.Values[i]
+ }
+ genForward(decl.Tok, name.Name, expr)
}
case *ast.ImportSpec:
default:
diff --git a/cmd/protoc-gen-go/testdata/import_public/a.pb.go b/cmd/protoc-gen-go/testdata/import_public/a.pb.go
index 70151ad..8814c7d 100644
--- a/cmd/protoc-gen-go/testdata/import_public/a.pb.go
+++ b/cmd/protoc-gen-go/testdata/import_public/a.pb.go
@@ -20,7 +20,6 @@
// Symbols defined in public import of import_public/sub/a.proto
-type Sub2Message = sub.Sub2Message
type E = sub.E
const E_ZERO = sub.E_ZERO
