GH-43796: [C++] Indent preprocessor directives

.clang-format

@@ -19,3 +19,4 @@ BasedOnStyle: Google
 ColumnLimit: 90
 DerivePointerAlignment: false
 IncludeBlocks: Preserve
+IndentPPDirectives: AfterHash

cpp/src/arrow/acero/aggregate_benchmark.cc

@@ -165,11 +165,11 @@ struct SumSentinelUnrolled : public Summer<T> {
   static void Sum(const ArrayType& array, SumState<T>* state) {
     SumState<T> local;
 
-#define SUM_NOT_NULL(ITEM)                                                  \
-  do {                                                                      \
-    local.total += values[i + ITEM] * Traits<T>::NotNull(values[i + ITEM]); \
-    local.valid_count++;                                                    \
-  } while (0)
+#  define SUM_NOT_NULL(ITEM)                                                  \
+    do {                                                                      \
+      local.total += values[i + ITEM] * Traits<T>::NotNull(values[i + ITEM]); \
+      local.valid_count++;                                                    \
+    } while (0)
 
     const auto values = array.raw_values();
     const auto length = array.length();
@@ -185,7 +185,7 @@ struct SumSentinelUnrolled : public Summer<T> {
       SUM_NOT_NULL(7);
     }
 
-#undef SUM_NOT_NULL
+#  undef SUM_NOT_NULL
 
     for (int64_t i = length_rounded * 8; i < length; ++i) {
       local.total += values[i] * Traits<T>::NotNull(values[i]);
@@ -256,7 +256,7 @@ struct SumBitmapVectorizeUnroll : public Summer<T> {
     for (int64_t i = 0; i < length_rounded; i += 8) {
       const uint8_t valid_byte = bitmap[i / 8];
 
-#define SUM_SHIFT(ITEM) (values[i + ITEM] * ((valid_byte >> ITEM) & 1))
+#  define SUM_SHIFT(ITEM) (values[i + ITEM] * ((valid_byte >> ITEM) & 1))
 
       if (valid_byte < 0xFF) {
         // Some nulls
@@ -277,7 +277,7 @@ struct SumBitmapVectorizeUnroll : public Summer<T> {
       }
     }
 
-#undef SUM_SHIFT
+#  undef SUM_SHIFT
 
     for (int64_t i = length_rounded; i < length; ++i) {
       if (bit_util::GetBit(bitmap, i)) {

cpp/src/arrow/acero/asof_join_node.cc

@@ -34,15 +34,15 @@
 #include "arrow/acero/options.h"
 #include "arrow/acero/unmaterialized_table_internal.h"
 #ifndef NDEBUG
-#include "arrow/acero/options_internal.h"
+#  include "arrow/acero/options_internal.h"
 #endif
 #include "arrow/acero/query_context.h"
 #include "arrow/acero/schema_util.h"
 #include "arrow/acero/util.h"
 #include "arrow/array/builder_binary.h"
 #include "arrow/array/builder_primitive.h"
 #ifndef NDEBUG
-#include "arrow/compute/function_internal.h"
+#  include "arrow/compute/function_internal.h"
 #endif
 #include "arrow/acero/time_series_util.h"
 #include "arrow/compute/key_hash_internal.h"
@@ -207,16 +207,16 @@ class DebugSync {
   std::unique_lock<std::mutex> debug_lock_;
 };
 
-#define DEBUG_SYNC(node, ...) DebugSync(node).insert(__VA_ARGS__)
-#define DEBUG_MANIP(manip) \
-  DebugSync::Manip([](DebugSync& d) -> DebugSync& { return d << manip; })
-#define NDEBUG_EXPLICIT
-#define DEBUG_ADD(ndebug, ...) ndebug, __VA_ARGS__
+#  define DEBUG_SYNC(node, ...) DebugSync(node).insert(__VA_ARGS__)
+#  define DEBUG_MANIP(manip) \
+    DebugSync::Manip([](DebugSync& d) -> DebugSync& { return d << manip; })
+#  define NDEBUG_EXPLICIT
+#  define DEBUG_ADD(ndebug, ...) ndebug, __VA_ARGS__
 #else
-#define DEBUG_SYNC(...)
-#define DEBUG_MANIP(...)
-#define NDEBUG_EXPLICIT explicit
-#define DEBUG_ADD(ndebug, ...) ndebug
+#  define DEBUG_SYNC(...)
+#  define DEBUG_MANIP(...)
+#  define NDEBUG_EXPLICIT explicit
+#  define DEBUG_ADD(ndebug, ...) ndebug
 #endif
 
 struct MemoStore {

cpp/src/arrow/acero/asof_join_node_test.cc

@@ -26,13 +26,13 @@
 #include "arrow/acero/exec_plan.h"
 #include "arrow/testing/future_util.h"
 #ifndef NDEBUG
-#include <sstream>
+#  include <sstream>
 #endif
 #include <unordered_set>
 
 #include "arrow/acero/options.h"
 #ifndef NDEBUG
-#include "arrow/acero/options_internal.h"
+#  include "arrow/acero/options_internal.h"
 #endif
 #include "arrow/acero/map_node.h"
 #include "arrow/acero/query_context.h"

cpp/src/arrow/acero/bloom_filter.h

@@ -18,7 +18,7 @@
 #pragma once
 
 #if defined(ARROW_HAVE_RUNTIME_AVX2)
-#include <immintrin.h>
+#  include <immintrin.h>
 #endif
 
 #include <atomic>

cpp/src/arrow/acero/bloom_filter_test.cc

@@ -503,9 +503,9 @@ TEST(BloomFilter, Scaling) {
   num_build.push_back(4000000);
 
   std::vector<BloomFilterBuildStrategy> strategies;
-#ifdef ARROW_ENABLE_THREADING
+#  ifdef ARROW_ENABLE_THREADING
   strategies.push_back(BloomFilterBuildStrategy::PARALLEL);
-#endif
+#  endif
   strategies.push_back(BloomFilterBuildStrategy::SINGLE_THREADED);
 
   for (const auto hardware_flags : HardwareFlagsForTesting()) {

cpp/src/arrow/acero/options_internal.h

@@ -18,8 +18,8 @@
 #pragma once
 
 #ifndef NDEBUG
-#include <mutex>
-#include <ostream>
+#  include <mutex>
+#  include <ostream>
 #endif
 
 namespace arrow {

cpp/src/arrow/acero/visibility.h

@@ -20,31 +20,31 @@
 #pragma once
 
 #if defined(_WIN32) || defined(__CYGWIN__)
-#if defined(_MSC_VER)
-#pragma warning(push)
-#pragma warning(disable : 4251)
-#else
-#pragma GCC diagnostic ignored "-Wattributes"
-#endif
+#  if defined(_MSC_VER)
+#    pragma warning(push)
+#    pragma warning(disable : 4251)
+#  else
+#    pragma GCC diagnostic ignored "-Wattributes"
+#  endif
 
-#ifdef ARROW_ACERO_STATIC
-#define ARROW_ACERO_EXPORT
-#elif defined(ARROW_ACERO_EXPORTING)
-#define ARROW_ACERO_EXPORT __declspec(dllexport)
-#else
-#define ARROW_ACERO_EXPORT __declspec(dllimport)
-#endif
+#  ifdef ARROW_ACERO_STATIC
+#    define ARROW_ACERO_EXPORT
+#  elif defined(ARROW_ACERO_EXPORTING)
+#    define ARROW_ACERO_EXPORT __declspec(dllexport)
+#  else
+#    define ARROW_ACERO_EXPORT __declspec(dllimport)
+#  endif
 
-#define ARROW_ACERO_NO_EXPORT
+#  define ARROW_ACERO_NO_EXPORT
 #else  // Not Windows
-#ifndef ARROW_ACERO_EXPORT
-#define ARROW_ACERO_EXPORT __attribute__((visibility("default")))
-#endif
-#ifndef ARROW_ACERO_NO_EXPORT
-#define ARROW_ACERO_NO_EXPORT __attribute__((visibility("hidden")))
-#endif
+#  ifndef ARROW_ACERO_EXPORT
+#    define ARROW_ACERO_EXPORT __attribute__((visibility("default")))
+#  endif
+#  ifndef ARROW_ACERO_NO_EXPORT
+#    define ARROW_ACERO_NO_EXPORT __attribute__((visibility("hidden")))
+#  endif
 #endif  // Not-Windows
 
 #if defined(_MSC_VER)
-#pragma warning(pop)
+#  pragma warning(pop)
 #endif

cpp/src/arrow/adapters/orc/adapter.cc

@@ -25,7 +25,7 @@
 #include <vector>
 
 #ifdef ARROW_ORC_NEED_TIME_ZONE_DATABASE_CHECK
-#include <filesystem>
+#  include <filesystem>
 #endif
 
 #include "arrow/adapters/orc/util.h"

cpp/src/arrow/c/abi.h

@@ -41,11 +41,11 @@ extern "C" {
 #endif
 
 #ifndef ARROW_C_DATA_INTERFACE
-#define ARROW_C_DATA_INTERFACE
+#  define ARROW_C_DATA_INTERFACE
 
-#define ARROW_FLAG_DICTIONARY_ORDERED 1
-#define ARROW_FLAG_NULLABLE 2
-#define ARROW_FLAG_MAP_KEYS_SORTED 4
+#  define ARROW_FLAG_DICTIONARY_ORDERED 1
+#  define ARROW_FLAG_NULLABLE 2
+#  define ARROW_FLAG_MAP_KEYS_SORTED 4
 
 struct ArrowSchema {
   // Array type description
@@ -83,41 +83,41 @@ struct ArrowArray {
 #endif  // ARROW_C_DATA_INTERFACE
 
 #ifndef ARROW_C_DEVICE_DATA_INTERFACE
-#define ARROW_C_DEVICE_DATA_INTERFACE
+#  define ARROW_C_DEVICE_DATA_INTERFACE
 
 // Spec and Documentation: https://arrow.apache.org/docs/format/CDeviceDataInterface.html
 
 // DeviceType for the allocated memory
 typedef int32_t ArrowDeviceType;
 
 // CPU device, same as using ArrowArray directly
-#define ARROW_DEVICE_CPU 1
+#  define ARROW_DEVICE_CPU 1
 // CUDA GPU Device
-#define ARROW_DEVICE_CUDA 2
+#  define ARROW_DEVICE_CUDA 2
 // Pinned CUDA CPU memory by cudaMallocHost
-#define ARROW_DEVICE_CUDA_HOST 3
+#  define ARROW_DEVICE_CUDA_HOST 3
 // OpenCL Device
-#define ARROW_DEVICE_OPENCL 4
+#  define ARROW_DEVICE_OPENCL 4
 // Vulkan buffer for next-gen graphics
-#define ARROW_DEVICE_VULKAN 7
+#  define ARROW_DEVICE_VULKAN 7
 // Metal for Apple GPU
-#define ARROW_DEVICE_METAL 8
+#  define ARROW_DEVICE_METAL 8
 // Verilog simulator buffer
-#define ARROW_DEVICE_VPI 9
+#  define ARROW_DEVICE_VPI 9
 // ROCm GPUs for AMD GPUs
-#define ARROW_DEVICE_ROCM 10
+#  define ARROW_DEVICE_ROCM 10
 // Pinned ROCm CPU memory allocated by hipMallocHost
-#define ARROW_DEVICE_ROCM_HOST 11
+#  define ARROW_DEVICE_ROCM_HOST 11
 // Reserved for extension
-#define ARROW_DEVICE_EXT_DEV 12
+#  define ARROW_DEVICE_EXT_DEV 12
 // CUDA managed/unified memory allocated by cudaMallocManaged
-#define ARROW_DEVICE_CUDA_MANAGED 13
+#  define ARROW_DEVICE_CUDA_MANAGED 13
 // unified shared memory allocated on a oneAPI non-partitioned device.
-#define ARROW_DEVICE_ONEAPI 14
+#  define ARROW_DEVICE_ONEAPI 14
 // GPU support for next-gen WebGPU standard
-#define ARROW_DEVICE_WEBGPU 15
+#  define ARROW_DEVICE_WEBGPU 15
 // Qualcomm Hexagon DSP
-#define ARROW_DEVICE_HEXAGON 16
+#  define ARROW_DEVICE_HEXAGON 16
 
 struct ArrowDeviceArray {
   // the Allocated Array
@@ -138,7 +138,7 @@ struct ArrowDeviceArray {
 #endif  // ARROW_C_DEVICE_DATA_INTERFACE
 
 #ifndef ARROW_C_STREAM_INTERFACE
-#define ARROW_C_STREAM_INTERFACE
+#  define ARROW_C_STREAM_INTERFACE
 
 struct ArrowArrayStream {
   // Callback to get the stream type
@@ -179,7 +179,7 @@ struct ArrowArrayStream {
 #endif  // ARROW_C_STREAM_INTERFACE
 
 #ifndef ARROW_C_DEVICE_STREAM_INTERFACE
-#define ARROW_C_DEVICE_STREAM_INTERFACE
+#  define ARROW_C_DEVICE_STREAM_INTERFACE
 
 // Equivalent to ArrowArrayStream, but for ArrowDeviceArrays.
 //

cpp/src/arrow/c/bridge_test.cc

@@ -48,7 +48,7 @@
 
 // TODO(GH-37221): Remove these ifdef checks when compute dependency is removed
 #ifdef ARROW_COMPUTE
-#include "arrow/compute/api_vector.h"
+#  include "arrow/compute/api_vector.h"
 #endif
 
 namespace arrow {

cpp/src/arrow/c/dlpack_abi.h

@@ -12,9 +12,9 @@
  * \brief Compatibility with C++
  */
 #ifdef __cplusplus
-#define DLPACK_EXTERN_C extern "C"
+#  define DLPACK_EXTERN_C extern "C"
 #else
-#define DLPACK_EXTERN_C
+#  define DLPACK_EXTERN_C
 #endif
 
 /*! \brief The current major version of dlpack */
@@ -25,13 +25,13 @@
 
 /*! \brief DLPACK_DLL prefix for windows */
 #ifdef _WIN32
-#ifdef DLPACK_EXPORTS
-#define DLPACK_DLL __declspec(dllexport)
+#  ifdef DLPACK_EXPORTS
+#    define DLPACK_DLL __declspec(dllexport)
+#  else
+#    define DLPACK_DLL __declspec(dllimport)
+#  endif
 #else
-#define DLPACK_DLL __declspec(dllimport)
-#endif
-#else
-#define DLPACK_DLL
+#  define DLPACK_DLL
 #endif
 
 #include <stddef.h>

cpp/src/arrow/compute/kernel.h

@@ -42,7 +42,7 @@
 // macOS defines PREALLOCATE as a preprocessor macro in the header sys/vnode.h.
 // No other BSD seems to do so. The name is used as an identifier in MemAllocation enum.
 #if defined(__APPLE__) && defined(PREALLOCATE)
-#undef PREALLOCATE
+#  undef PREALLOCATE
 #endif
 
 namespace arrow {

cpp/src/arrow/compute/kernels/scalar_cast_string.cc

@@ -217,8 +217,8 @@ struct TemporalToStringCastFunctor<O, TimestampType> {
 
 #if defined(_MSC_VER)
 // Silence warning: """'visitor': unreferenced local variable"""
-#pragma warning(push)
-#pragma warning(disable : 4101)
+#  pragma warning(push)
+#  pragma warning(disable : 4101)
 #endif
 
 struct Utf8Validator {
@@ -422,7 +422,7 @@ BinaryToBinaryCastExec(KernelContext* ctx, const ExecSpan& batch, ExecResult* ou
 }
 
 #if defined(_MSC_VER)
-#pragma warning(pop)
+#  pragma warning(pop)
 #endif
 
 // ----------------------------------------------------------------------