Generate an annotation to suppress deprecation warnings

The valueOf method on enums is deprecated, but for compatibility reasons
the generated code has to keep using it. We can use an annotation to
suppress the deprecation warnings.

src/google/protobuf/compiler/java/java_enum_field.cc

@@ -80,7 +80,7 @@ void SetEnumVariables(const FieldDescriptor* descriptor,
   // Use deprecated valueOf() method to be compatible with old generated code
   // for v2.5.0/v2.6.1.
   // TODO(xiaofeng): Use "forNumber" when we no longer support compatibility
-  // with v2.5.0/v2.6.1.
+  // with v2.5.0/v2.6.1, and remove the @SuppressWarnings annotations.
   (*variables)["for_number"] = "valueOf";
 
   if (SupportFieldPresence(descriptor->file())) {
@@ -199,6 +199,7 @@ GenerateMembers(io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_);
   printer->Print(variables_,
     "$deprecation$public $type$ ${$get$capitalized_name$$}$() {\n"
+    "  @SuppressWarnings(\"deprecation\")\n"
     "  $type$ result = $type$.$for_number$($name$_);\n"
     "  return result == null ? $unknown$ : result;\n"
     "}\n");
@@ -237,6 +238,7 @@ GenerateBuilderMembers(io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_);
   printer->Print(variables_,
     "$deprecation$public $type$ ${$get$capitalized_name$$}$() {\n"
+    "  @SuppressWarnings(\"deprecation\")\n"
     "  $type$ result = $type$.$for_number$($name$_);\n"
     "  return result == null ? $unknown$ : result;\n"
     "}\n");
@@ -320,6 +322,7 @@ GenerateParsingCode(io::Printer* printer) const {
   } else {
     printer->Print(variables_,
       "int rawValue = input.readEnum();\n"
+    "  @SuppressWarnings(\"deprecation\")\n"
       "$type$ value = $type$.$for_number$(rawValue);\n"
       "if (value == null) {\n"
       "  unknownFields.mergeVarintField($number$, rawValue);\n"
@@ -412,6 +415,7 @@ GenerateMembers(io::Printer* printer) const {
   printer->Print(variables_,
     "$deprecation$public $type$ ${$get$capitalized_name$$}$() {\n"
     "  if ($has_oneof_case_message$) {\n"
+    "    @SuppressWarnings(\"deprecation\")\n"
     "    $type$ result = $type$.$for_number$(\n"
     "        (java.lang.Integer) $oneof_name$_);\n"
     "    return result == null ? $unknown$ : result;\n"
@@ -456,6 +460,7 @@ GenerateBuilderMembers(io::Printer* printer) const {
   printer->Print(variables_,
     "$deprecation$public $type$ ${$get$capitalized_name$$}$() {\n"
     "  if ($has_oneof_case_message$) {\n"
+    "    @SuppressWarnings(\"deprecation\")\n"
     "    $type$ result = $type$.$for_number$(\n"
     "        (java.lang.Integer) $oneof_name$_);\n"
     "    return result == null ? $unknown$ : result;\n"
@@ -517,6 +522,7 @@ GenerateParsingCode(io::Printer* printer) const {
   } else {
     printer->Print(variables_,
       "int rawValue = input.readEnum();\n"
+      "@SuppressWarnings(\"deprecation\")\n"
       "$type$ value = $type$.$for_number$(rawValue);\n"
       "if (value == null) {\n"
       "  unknownFields.mergeVarintField($number$, rawValue);\n"
@@ -626,6 +632,7 @@ GenerateMembers(io::Printer* printer) const {
     "        new com.google.protobuf.Internal.ListAdapter.Converter<\n"
     "            java.lang.Integer, $type$>() {\n"
     "          public $type$ convert(java.lang.Integer from) {\n"
+    "            @SuppressWarnings(\"deprecation\")\n"
     "            $type$ result = $type$.$for_number$(from);\n"
     "            return result == null ? $unknown$ : result;\n"
     "          }\n"
@@ -879,6 +886,7 @@ GenerateParsingCode(io::Printer* printer) const {
   } else {
     printer->Print(variables_,
       "int rawValue = input.readEnum();\n"
+      "@SuppressWarnings(\"deprecation\")\n"
       "$type$ value = $type$.$for_number$(rawValue);\n"
       "if (value == null) {\n"
       "  unknownFields.mergeVarintField($number$, rawValue);\n"