Remove global -Wno-return-type from CMakeLists.txt (#9387)

Summary:
This PR makes a change to remove the globally applied `-Wno-return-type`, fixes some violations. This PR originally #4618 disabled it. In the case of a code bug, it may become difficult to diagnose the actual cause. An example of this is

```
#include <stdio.h>

bool test1()
{
    printf("Called inner\n");
}
void test()
{
    test1();
}

int main(int argc, char* argv[])
{
    printf("Called test\n");
    test();
    printf("Finished test\n");
    return 0;
}
```
which crashes when compiled with -O2 due to bad codegen.

Pull Request resolved: #9387

Reviewed By: pedroerp

Differential Revision: D55933467

Pulled By: mbasmanova

fbshipit-source-id: da748fc5df19adb3d6e295973cc12e75ac43f2c1

CMakeLists.txt

@@ -336,8 +336,7 @@ if("${ENABLE_ALL_WARNINGS}")
          -Wno-strict-aliasing \
          -Wno-type-limits \
          -Wno-stringop-overflow \
-         -Wno-stringop-overread \
-         -Wno-return-type")
+         -Wno-stringop-overread")
   endif()
 
   set(KNOWN_WARNINGS

velox/connectors/hive/HivePartitionFunction.cpp

@@ -51,6 +51,7 @@ inline uint32_t hashOne(
   VELOX_UNSUPPORTED(
       "Hive partitioning function doesn't support {} type",
       TypeTraits<kind>::name);
+  return 0; // Make compiler happy.
 }
 
 template <>

velox/connectors/hive/storage_adapters/abfs/AbfsWriteFile.cpp

@@ -118,11 +118,10 @@ class AbfsWriteFile::Impl {
       blobStorageFileClient_->getProperties();
       return true;
     } catch (Azure::Storage::StorageException& e) {
-      if (e.StatusCode == Azure::Core::Http::HttpStatusCode::NotFound) {
-        return false;
-      } else {
+      if (e.StatusCode != Azure::Core::Http::HttpStatusCode::NotFound) {
         throwStorageExceptionWithOperationDetails("GetProperties", path_, e);
       }
+      return false;
     }
   }
 

velox/exec/tests/TableWriteTest.cpp

@@ -64,6 +64,7 @@ std::string testModeString(TestMode mode) {
     case TestMode::kBucketed:
       return "BUCKETED";
   }
+  VELOX_UNREACHABLE();
 }
 
 static std::shared_ptr<core::AggregationNode> generateAggregationNode(

velox/functions/prestosql/types/JsonType.cpp

@@ -643,6 +643,7 @@ struct CastFromJsonTypedImpl {
     static simdjson::error_code apply(Input, exec::GenericWriter&) {
       VELOX_NYI(
           "Casting from JSON to {} is not supported.", TypeTraits<kind>::name);
+      return simdjson::error_code::UNEXPECTED_ERROR; // Make compiler happy.
     }
   };
 

velox/functions/remote/if/GetSerde.cpp

@@ -28,6 +28,6 @@ std::unique_ptr<VectorSerde> getSerde(const remote::PageFormat& format) {
     case remote::PageFormat::SPARK_UNSAFE_ROW:
       return std::make_unique<serializer::spark::UnsafeRowVectorSerde>();
   }
+  VELOX_UNREACHABLE();
 }
-
 } // namespace facebook::velox::functions