How can I deprecate whole message in Protocol Buffers?

According to documentation:

deprecated (field option): If set to true, indicates that the field is deprecated and should not be used by new code.

Example of use:

message Foo {
 string old_field = 1 [deprecated = true];
}

• How we can deprecate the whole message?

You can set deprecated as a top level option on the message:

message Foo {
   option deprecated = true;
   string old_field = 1;
}