Always generate body for python code elements

Since

    #...
    class Service:

    class NextService:
    #...

without a body or `pass` under `Service` is invalid
Python, we ensure a `pass` statement is always
emitted to make the generated code valid.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/compiler/python_generator.cc b/src/compiler/python_generator.cc
index 2649c1688d..50ee54abff 100644
--- a/src/compiler/python_generator.cc
+++ b/src/compiler/python_generator.cc
@@ -101,6 +101,14 @@ PrivateGenerator::PrivateGenerator(const GeneratorConfiguration& config,
 void PrivateGenerator::PrintAllComments(StringVector comments,
                                         grpc_generator::Printer* out) {
   if (comments.empty()) {
+    // Python requires code structures like class and def to have
+    // a body, even if it is just "pass" or a docstring.  We need
+    // to ensure not to generate empty bodies. We could do something
+    // smarter and more sophisticated, but at the moment, if there is
+    // no docstring to print, we simply emit "pass" to ensure validity
+    // of the generated code.
+    out->Print("# missing associated documentation comment in .proto file\n");
+    out->Print("pass\n");
     return;
   }
   out->Print("\"\"\"");