Breaking change: disallow incorrect ctype usage

PiperOrigin-RevId: 597091014

src/google/protobuf/compiler/cpp/generator.cc

@@ -376,7 +376,6 @@ absl::Status CppGenerator::ValidateFeatures(const FileDescriptor* file) const {
       }
     }
 
-#ifdef PROTOBUF_FUTURE_REMOVE_WRONG_CTYPE
     if (field.options().has_ctype()) {
       if (field.cpp_type() != FieldDescriptor::CPPTYPE_STRING) {
         status = absl::FailedPreconditionError(absl::StrCat(
@@ -391,7 +390,6 @@ absl::Status CppGenerator::ValidateFeatures(const FileDescriptor* file) const {
         }
       }
     }
-#endif  // !PROTOBUF_FUTURE_REMOVE_WRONG_CTYPE
   });
   return status;
 }

src/google/protobuf/compiler/cpp/generator_unittest.cc

@@ -148,7 +148,6 @@ TEST_F(CppGeneratorTest, LegacyClosedEnumImplicit) {
       "Field Foo.bar has a closed enum type with implicit presence.");
 }
 
-#ifdef PROTOBUF_FUTURE_REMOVE_WRONG_CTYPE
 TEST_F(CppGeneratorTest, CtypeOnNoneStringFieldTest) {
   CreateTempFile("foo.proto",
                  R"schema(
@@ -181,7 +180,6 @@ TEST_F(CppGeneratorTest, CtypeOnExtensionTest) {
       "Extension bar specifies ctype=CORD which is "
       "not supported for extensions.");
 }
-#endif  // !PROTOBUF_FUTURE_REMOVE_WRONG_CTYPE
 }  // namespace
 }  // namespace cpp
 }  // namespace compiler

src/google/protobuf/port_def.inc

@@ -167,10 +167,6 @@ static_assert(PROTOBUF_ABSL_MIN(20230125, 3),
 // Owner: ezb@
 #define PROTOBUF_FUTURE_REMOVE_CONST_REPEATEDFIELD_GETARENA_API 1
 
-// Used to lock down wrong ctype usages in proto file.
-// Owner: jieluo@
-#define PROTOBUF_FUTURE_REMOVE_WRONG_CTYPE 1
-
 #endif
 
 // Defines the Protobuf C++ Version for checking version compatibility at