apacheGH-41478: [C++] Clean up more redundant move warnings (apache#4…

…1487) ### Rationale for this change Minor warning cleanup for downstream libraries trying to get warning-free builds ### What changes are included in this PR? Removed redundant std::move from return statements ### Are these changes tested? Builds cleanly ### Are there any user-facing changes? No * GitHub Issue: apache#41478 Authored-by: Will Ayd <[email protected]> Signed-off-by: Benjamin Kietzman <[email protected]>
mapleFU · May 24, 2024 · 3a4fcff · 3a4fcff
1 parent b275483
commit 3a4fcff
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Showing 87 changed files with 218 additions and 198 deletions.
diff --git a/cpp/cmake_modules/SetupCxxFlags.cmake b/cpp/cmake_modules/SetupCxxFlags.cmake
@@ -330,8 +330,9 @@ if("${BUILD_WARNING_LEVEL}" STREQUAL "CHECKIN")
     set(CXX_COMMON_FLAGS "${CXX_COMMON_FLAGS} -Wall")
     set(CXX_COMMON_FLAGS "${CXX_COMMON_FLAGS} -Wno-conversion")
     set(CXX_COMMON_FLAGS "${CXX_COMMON_FLAGS} -Wno-sign-conversion")
-    set(CXX_COMMON_FLAGS "${CXX_COMMON_FLAGS} -Wunused-result")
     set(CXX_COMMON_FLAGS "${CXX_COMMON_FLAGS} -Wdate-time")
+    string(APPEND CXX_ONLY_FLAGS " -Wredundant-move")
+    set(CXX_COMMON_FLAGS "${CXX_COMMON_FLAGS} -Wunused-result")
   elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Intel" OR CMAKE_CXX_COMPILER_ID STREQUAL
                                                    "IntelLLVM")
     if(WIN32)

diff --git a/cpp/src/arrow/acero/aggregate_internal.cc b/cpp/src/arrow/acero/aggregate_internal.cc
@@ -102,7 +102,7 @@ Result<std::unique_ptr<KernelState>> InitKernel(const HashAggregateKernel* kerne
   ARROW_ASSIGN_OR_RAISE(
       auto state,
       kernel->init(&kernel_ctx, KernelInitArgs{kernel, aggr_in_types, options}));
-  return std::move(state);
+  return state;
 }
 
 Result<std::vector<const HashAggregateKernel*>> GetKernels(
@@ -129,7 +129,7 @@ Result<std::vector<std::unique_ptr<KernelState>>> InitKernels(
     ARROW_ASSIGN_OR_RAISE(states[i],
                           InitKernel(kernels[i], ctx, aggregates[i], in_types[i]));
   }
-  return std::move(states);
+  return states;
 }
 
 Result<FieldVector> ResolveKernels(
@@ -242,7 +242,7 @@ Result<std::vector<Datum>> ExtractValues(const ExecBatch& input_batch,
       DCHECK(false);
     }
   }
-  return std::move(values);
+  return values;
 }
 
 }  // namespace aggregate

diff --git a/cpp/src/arrow/acero/backpressure_handler.h b/cpp/src/arrow/acero/backpressure_handler.h
@@ -45,7 +45,7 @@ class BackpressureHandler {
     }
     BackpressureHandler backpressure_handler(input, low_threshold, high_threshold,
                                              std::move(backpressure_control));
-    return std::move(backpressure_handler);
+    return backpressure_handler;
   }
 
   void Handle(size_t start_level, size_t end_level) {

diff --git a/cpp/src/arrow/acero/hash_aggregate_test.cc b/cpp/src/arrow/acero/hash_aggregate_test.cc
@@ -318,7 +318,7 @@ Result<Datum> RunGroupBy(const BatchesWithSchema& input,
           {
               {"source",
                SourceNodeOptions{input.schema, input.gen(use_threads, /*slow=*/false)}},
-              {"aggregate", AggregateNodeOptions{std::move(aggregates), std::move(keys),
+              {"aggregate", AggregateNodeOptions{aggregates, std::move(keys),
                                                  std::move(segment_keys)}},
               {"sink", SinkNodeOptions{&sink_gen}},
           })

diff --git a/cpp/src/arrow/acero/hash_join.cc b/cpp/src/arrow/acero/hash_join.cc
@@ -791,7 +791,7 @@ class HashJoinBasicImpl : public HashJoinImpl {
 
 Result<std::unique_ptr<HashJoinImpl>> HashJoinImpl::MakeBasic() {
   std::unique_ptr<HashJoinImpl> impl{new HashJoinBasicImpl()};
-  return std::move(impl);
+  return impl;
 }
 
 }  // namespace acero

diff --git a/cpp/src/arrow/acero/hash_join_node.cc b/cpp/src/arrow/acero/hash_join_node.cc
@@ -351,7 +351,7 @@ Result<Expression> HashJoinSchema::BindFilter(Expression filter,
                                               const Schema& right_schema,
                                               ExecContext* exec_context) {
   if (filter.IsBound() || filter == literal(true)) {
-    return std::move(filter);
+    return filter;
   }
   // Step 1: Construct filter schema
   FieldVector fields;
@@ -386,7 +386,7 @@ Result<Expression> HashJoinSchema::BindFilter(Expression filter,
                              filter.ToString(), " evaluates to ",
                              filter.type()->ToString());
   }
-  return std::move(filter);
+  return filter;
 }
 
 Expression HashJoinSchema::RewriteFilterToUseFilterSchema(

diff --git a/cpp/src/arrow/acero/order_by_impl.cc b/cpp/src/arrow/acero/order_by_impl.cc
@@ -93,14 +93,14 @@ Result<std::unique_ptr<OrderByImpl>> OrderByImpl::MakeSort(
     ExecContext* ctx, const std::shared_ptr<Schema>& output_schema,
     const SortOptions& options) {
   std::unique_ptr<OrderByImpl> impl{new SortBasicImpl(ctx, output_schema, options)};
-  return std::move(impl);
+  return impl;
 }
 
 Result<std::unique_ptr<OrderByImpl>> OrderByImpl::MakeSelectK(
     ExecContext* ctx, const std::shared_ptr<Schema>& output_schema,
     const SelectKOptions& options) {
   std::unique_ptr<OrderByImpl> impl{new SelectKBasicImpl(ctx, output_schema, options)};
-  return std::move(impl);
+  return impl;
 }
 
 }  // namespace acero

diff --git a/cpp/src/arrow/acero/swiss_join.cc b/cpp/src/arrow/acero/swiss_join.cc
@@ -2985,7 +2985,7 @@ class SwissJoin : public HashJoinImpl {
 
 Result<std::unique_ptr<HashJoinImpl>> HashJoinImpl::MakeSwiss() {
   std::unique_ptr<HashJoinImpl> impl{new SwissJoin()};
-  return std::move(impl);
+  return impl;
 }
 
 }  // namespace acero

diff --git a/cpp/src/arrow/acero/task_util.cc b/cpp/src/arrow/acero/task_util.cc
@@ -424,7 +424,7 @@ void TaskSchedulerImpl::Abort(AbortContinuationImpl impl) {
 
 std::unique_ptr<TaskScheduler> TaskScheduler::Make() {
   std::unique_ptr<TaskSchedulerImpl> impl{new TaskSchedulerImpl()};
-  return std::move(impl);
+  return impl;
 }
 
 }  // namespace acero

diff --git a/cpp/src/arrow/acero/tpch_node.cc b/cpp/src/arrow/acero/tpch_node.cc
@@ -336,7 +336,7 @@ Result<Datum> TpchPseudotext::GenerateComments(size_t num_comments, size_t min_l
   }
   ArrayData ad(utf8(), num_comments,
                {nullptr, std::move(offset_buffer), std::move(comment_buffer)});
-  return std::move(ad);
+  return ad;
 }
 
 bool TpchPseudotext::GenerateWord(int64_t& offset, random::pcg32_fast& rng, char* arr,
@@ -611,7 +611,7 @@ Result<Datum> RandomVString(random::pcg32_fast& rng, int64_t num_rows, int32_t m
   for (int32_t i = 0; i < offsets[num_rows]; i++) str[i] = alpha_numerics[char_dist(rng)];
 
   ArrayData ad(utf8(), num_rows, {nullptr, std::move(offset_buff), std::move(str_buff)});
-  return std::move(ad);
+  return ad;
 }
 
 void GeneratePhoneNumber(char* out, random::pcg32_fast& rng, int32_t country) {
@@ -677,7 +677,7 @@ class PartAndPartSupplierGenerator {
       if (!part_output_queue_.empty()) {
         ExecBatch batch = std::move(part_output_queue_.front());
         part_output_queue_.pop();
-        return std::move(batch);
+        return batch;
       } else if (part_rows_generated_ == part_rows_to_generate_) {
         return std::nullopt;
       } else {
@@ -732,7 +732,7 @@ class PartAndPartSupplierGenerator {
       if (!partsupp_output_queue_.empty()) {
         ExecBatch result = std::move(partsupp_output_queue_.front());
         partsupp_output_queue_.pop();
-        return std::move(result);
+        return result;
       }
     }
     {
@@ -1337,7 +1337,7 @@ class OrdersAndLineItemGenerator {
       if (!orders_output_queue_.empty()) {
         ExecBatch batch = std::move(orders_output_queue_.front());
         orders_output_queue_.pop();
-        return std::move(batch);
+        return batch;
       } else if (orders_rows_generated_ == orders_rows_to_generate_) {
         return std::nullopt;
       } else {
@@ -1401,12 +1401,12 @@ class OrdersAndLineItemGenerator {
     if (from_queue) {
       ARROW_DCHECK(queued.length <= batch_size_);
       tld.first_batch_offset = queued.length;
-      if (queued.length == batch_size_) return std::move(queued);
+      if (queued.length == batch_size_) return queued;
     }
     {
       std::lock_guard<std::mutex> lock(orders_output_queue_mutex_);
       if (orders_rows_generated_ == orders_rows_to_generate_) {
-        if (from_queue) return std::move(queued);
+        if (from_queue) return queued;
         return std::nullopt;
       }
 

diff --git a/cpp/src/arrow/adapters/orc/adapter.cc b/cpp/src/arrow/adapters/orc/adapter.cc
@@ -566,7 +566,7 @@ Result<std::unique_ptr<ORCFileReader>> ORCFileReader::Open(
 #endif
   auto result = std::unique_ptr<ORCFileReader>(new ORCFileReader());
   RETURN_NOT_OK(result->impl_->Open(file, pool));
-  return std::move(result);
+  return result;
 }
 
 Result<std::shared_ptr<const KeyValueMetadata>> ORCFileReader::ReadMetadata() {
@@ -837,7 +837,7 @@ Result<std::unique_ptr<ORCFileWriter>> ORCFileWriter::Open(
       std::unique_ptr<ORCFileWriter>(new ORCFileWriter());
   Status status = result->impl_->Open(output_stream, writer_options);
   RETURN_NOT_OK(status);
-  return std::move(result);
+  return result;
 }
 
 Status ORCFileWriter::Write(const Table& table) { return impl_->Write(table); }

diff --git a/cpp/src/arrow/adapters/orc/util.cc b/cpp/src/arrow/adapters/orc/util.cc
@@ -1026,7 +1026,7 @@ Result<std::unique_ptr<liborc::Type>> GetOrcType(const DataType& type) {
         SetAttributes(*it, orc_subtype.get());
         out_type->addStructField(field_name, std::move(orc_subtype));
       }
-      return std::move(out_type);
+      return out_type;
     }
     case Type::type::MAP: {
       const auto& key_field = checked_cast<const MapType&>(type).key_field();
@@ -1048,7 +1048,7 @@ Result<std::unique_ptr<liborc::Type>> GetOrcType(const DataType& type) {
         SetAttributes(arrow_field, orc_subtype.get());
         out_type->addUnionChild(std::move(orc_subtype));
       }
-      return std::move(out_type);
+      return out_type;
     }
     default: {
       return Status::NotImplemented("Unknown or unsupported Arrow type: ",
@@ -1195,7 +1195,7 @@ Result<std::unique_ptr<liborc::Type>> GetOrcType(const Schema& schema) {
     SetAttributes(field, orc_subtype.get());
     out_type->addStructField(field->name(), std::move(orc_subtype));
   }
-  return std::move(out_type);
+  return out_type;
 }
 
 Result<std::shared_ptr<const KeyValueMetadata>> GetFieldMetadata(

diff --git a/cpp/src/arrow/array/array_nested.cc b/cpp/src/arrow/array/array_nested.cc
@@ -1177,7 +1177,7 @@ void SparseUnionArray::SetData(std::shared_ptr<ArrayData> data) {
 }
 
 void DenseUnionArray::SetData(const std::shared_ptr<ArrayData>& data) {
-  this->UnionArray::SetData(std::move(data));
+  this->UnionArray::SetData(data);
 
   ARROW_CHECK_EQ(data_->type->id(), Type::DENSE_UNION);
   ARROW_CHECK_EQ(data_->buffers.size(), 3);

diff --git a/cpp/src/arrow/array/builder_base.h b/cpp/src/arrow/array/builder_base.h
@@ -332,7 +332,7 @@ inline Result<std::unique_ptr<ArrayBuilder>> MakeBuilder(
     const std::shared_ptr<DataType>& type, MemoryPool* pool = default_memory_pool()) {
   std::unique_ptr<ArrayBuilder> out;
   ARROW_RETURN_NOT_OK(MakeBuilder(pool, type, &out));
-  return std::move(out);
+  return out;
 }
 
 /// \brief Construct an empty ArrayBuilder corresponding to the data
@@ -346,7 +346,7 @@ inline Result<std::unique_ptr<ArrayBuilder>> MakeBuilderExactIndex(
     const std::shared_ptr<DataType>& type, MemoryPool* pool = default_memory_pool()) {
   std::unique_ptr<ArrayBuilder> out;
   ARROW_RETURN_NOT_OK(MakeBuilderExactIndex(pool, type, &out));
-  return std::move(out);
+  return out;
 }
 
 /// \brief Construct an empty DictionaryBuilder initialized optionally
@@ -365,7 +365,7 @@ inline Result<std::unique_ptr<ArrayBuilder>> MakeDictionaryBuilder(
     MemoryPool* pool = default_memory_pool()) {
   std::unique_ptr<ArrayBuilder> out;
   ARROW_RETURN_NOT_OK(MakeDictionaryBuilder(pool, type, dictionary, &out));
-  return std::move(out);
+  return out;
 }
 
 }  // namespace arrow
diff --git a/cpp/src/arrow/array/builder_run_end.cc b/cpp/src/arrow/array/builder_run_end.cc
@@ -162,8 +162,7 @@ Status RunCompressorBuilder::FinishInternal(std::shared_ptr<ArrayData>* out) {
 RunEndEncodedBuilder::ValueRunBuilder::ValueRunBuilder(
     MemoryPool* pool, const std::shared_ptr<ArrayBuilder>& value_builder,
     const std::shared_ptr<DataType>& value_type, RunEndEncodedBuilder& ree_builder)
-    : RunCompressorBuilder(pool, std::move(value_builder), std::move(value_type)),
-      ree_builder_(ree_builder) {}
+    : RunCompressorBuilder(pool, value_builder, value_type), ree_builder_(ree_builder) {}
 
 RunEndEncodedBuilder::RunEndEncodedBuilder(
     MemoryPool* pool, const std::shared_ptr<ArrayBuilder>& run_end_builder,

diff --git a/cpp/src/arrow/array/concatenate.cc b/cpp/src/arrow/array/concatenate.cc
@@ -522,7 +522,8 @@ class ConcatenateImpl {
       }
       out_data += data->length * index_width;
     }
-    return std::move(out);
+    // R build with openSUSE155 requires an explicit shared_ptr construction
+    return std::shared_ptr<Buffer>(std::move(out));
   }
 
   Status Visit(const DictionaryType& d) {

diff --git a/cpp/src/arrow/array/util.cc b/cpp/src/arrow/array/util.cc
@@ -125,7 +125,8 @@ class ArrayDataEndianSwapper {
     for (int64_t i = 0; i < length; i++) {
       out_data[i] = bit_util::ByteSwap(in_data[i]);
     }
-    return std::move(out_buffer);
+    // R build with openSUSE155 requires an explicit shared_ptr construction
+    return std::shared_ptr<Buffer>(std::move(out_buffer));
   }
 
   template <typename VALUE_TYPE>

diff --git a/cpp/src/arrow/buffer.cc b/cpp/src/arrow/buffer.cc
@@ -41,7 +41,8 @@ Result<std::shared_ptr<Buffer>> Buffer::CopySlice(const int64_t start,
 
   ARROW_ASSIGN_OR_RAISE(auto new_buffer, AllocateResizableBuffer(nbytes, pool));
   std::memcpy(new_buffer->mutable_data(), data() + start, static_cast<size_t>(nbytes));
-  return std::move(new_buffer);
+  // R build with openSUSE155 requires an explicit shared_ptr construction
+  return std::shared_ptr<Buffer>(std::move(new_buffer));
 }
 
 Buffer::Buffer() : Buffer(memory_pool::internal::kZeroSizeArea, 0) {}
@@ -185,7 +186,8 @@ Result<std::shared_ptr<Buffer>> AllocateBitmap(int64_t length, MemoryPool* pool)
   if (buf->size() > 0) {
     buf->mutable_data()[buf->size() - 1] = 0;
   }
-  return std::move(buf);
+  // R build with openSUSE155 requires an explicit shared_ptr construction
+  return std::shared_ptr<Buffer>(std::move(buf));
 }
 
 Result<std::shared_ptr<Buffer>> AllocateEmptyBitmap(int64_t length, MemoryPool* pool) {
@@ -197,7 +199,8 @@ Result<std::shared_ptr<Buffer>> AllocateEmptyBitmap(int64_t length, int64_t alig
   ARROW_ASSIGN_OR_RAISE(auto buf,
                         AllocateBuffer(bit_util::BytesForBits(length), alignment, pool));
   memset(buf->mutable_data(), 0, static_cast<size_t>(buf->size()));
-  return std::move(buf);
+  // R build with openSUSE155 requires an explicit shared_ptr construction
+  return std::shared_ptr<Buffer>(std::move(buf));
 }
 
 Status AllocateEmptyBitmap(int64_t length, std::shared_ptr<Buffer>* out) {
@@ -219,7 +222,8 @@ Result<std::shared_ptr<Buffer>> ConcatenateBuffers(
       out_data += buffer->size();
     }
   }
-  return std::move(out);
+  // R build with openSUSE155 requires an explicit shared_ptr construction
+  return std::shared_ptr<Buffer>(std::move(out));
 }
 
 }  // namespace arrow
diff --git a/cpp/src/arrow/c/bridge_test.cc b/cpp/src/arrow/c/bridge_test.cc
@@ -1362,7 +1362,7 @@ class MyMemoryManager : public CPUMemoryManager {
     if (buf.size() > 0) {
       memcpy(dest->mutable_data(), buf.data(), static_cast<size_t>(buf.size()));
     }
-    return std::move(dest);
+    return dest;
   }
 };
 

diff --git a/cpp/src/arrow/compute/exec.cc b/cpp/src/arrow/compute/exec.cc
@@ -923,7 +923,7 @@ class ScalarExecutor : public KernelExecutorImpl<ScalarKernel> {
       DCHECK(output.is_array_data());
 
       // Emit a result for each chunk
-      RETURN_NOT_OK(EmitResult(std::move(output.array_data()), listener));
+      RETURN_NOT_OK(EmitResult(output.array_data(), listener));
     }
     return Status::OK();
   }
@@ -1107,7 +1107,7 @@ class VectorExecutor : public KernelExecutorImpl<VectorKernel> {
       RETURN_NOT_OK(PropagateNulls(kernel_ctx_, span, out.array_data().get()));
     }
     RETURN_NOT_OK(kernel_->exec(kernel_ctx_, span, &out));
-    return EmitResult(std::move(out.array_data()), listener);
+    return EmitResult(out.array_data(), listener);
   }
 
   Status ExecChunked(const ExecBatch& batch, ExecListener* listener) {
@@ -1116,10 +1116,10 @@ class VectorExecutor : public KernelExecutorImpl<VectorKernel> {
     ARROW_ASSIGN_OR_RAISE(out.value, PrepareOutput(batch.length));
     RETURN_NOT_OK(kernel_->exec_chunked(kernel_ctx_, batch, &out));
     if (out.is_array()) {
-      return EmitResult(std::move(out.array()), listener);
+      return EmitResult(out.array(), listener);
     } else {
       DCHECK(out.is_chunked_array());
-      return EmitResult(std::move(out.chunked_array()), listener);
+      return EmitResult(out.chunked_array(), listener);
     }
   }
 

diff --git a/cpp/src/arrow/compute/expression.cc b/cpp/src/arrow/compute/expression.cc
@@ -1645,7 +1645,7 @@ Expression and_(const std::vector<Expression>& operands) {
 
   Expression folded = operands.front();
   for (auto it = operands.begin() + 1; it != operands.end(); ++it) {
-    folded = and_(std::move(folded), std::move(*it));
+    folded = and_(std::move(folded), *it);
   }
   return folded;
 }
@@ -1659,7 +1659,7 @@ Expression or_(const std::vector<Expression>& operands) {
 
   Expression folded = operands.front();
   for (auto it = operands.begin() + 1; it != operands.end(); ++it) {
-    folded = or_(std::move(folded), std::move(*it));
+    folded = or_(std::move(folded), *it);
   }
   return folded;
 }