Reduce compiler warnings on CPU-only build. (#8483)

src/data/data.cc

@@ -734,9 +734,7 @@ void MetaInfo::Validate(int32_t device) const {
 }
 
 #if !defined(XGBOOST_USE_CUDA)
-void MetaInfo::SetInfoFromCUDA(Context const& ctx, StringView key, Json arr) {
-  common::AssertGPUSupport();
-}
+void MetaInfo::SetInfoFromCUDA(Context const&, StringView, Json) { common::AssertGPUSupport(); }
 #endif  // !defined(XGBOOST_USE_CUDA)
 
 using DMatrixThreadLocal =

src/data/ellpack_page.cc

@@ -12,7 +12,7 @@ class EllpackPageImpl {};
 
 EllpackPage::EllpackPage() = default;
 
-EllpackPage::EllpackPage(DMatrix* dmat, const BatchParam& param) {
+EllpackPage::EllpackPage(DMatrix*, const BatchParam&) {
   LOG(FATAL) << "Internal Error: XGBoost is not compiled with CUDA but "
                 "EllpackPage is required";
 }
@@ -22,7 +22,7 @@ EllpackPage::~EllpackPage() {
                 "EllpackPage is required";
 }
 
-void EllpackPage::SetBaseRowId(size_t row_id) {
+void EllpackPage::SetBaseRowId(std::size_t) {
   LOG(FATAL) << "Internal Error: XGBoost is not compiled with CUDA but "
                 "EllpackPage is required";
 }

src/data/ellpack_page.cu

@@ -25,7 +25,7 @@ EllpackPage::EllpackPage(EllpackPage&& that) { std::swap(impl_, that.impl_); }
 
 size_t EllpackPage::Size() const { return impl_->Size(); }
 
-void EllpackPage::SetBaseRowId(size_t row_id) { impl_->SetBaseRowId(row_id); }
+void EllpackPage::SetBaseRowId(std::size_t row_id) { impl_->SetBaseRowId(row_id); }
 
 // Bin each input data entry, store the bin indices in compressed form.
 __global__ void CompressBinEllpackKernel(

src/data/ellpack_page.cuh

@@ -190,7 +190,7 @@ class EllpackPageImpl {
   size_t Size() const;
 
   /*! \brief Set the base row id for this page. */
-  void SetBaseRowId(size_t row_id) {
+  void SetBaseRowId(std::size_t row_id) {
     base_rowid = row_id;
   }
 

src/data/sparse_page_dmatrix.cc

@@ -19,7 +19,7 @@ const MetaInfo &SparsePageDMatrix::Info() const { return info_; }
 
 namespace detail {
 // Use device dispatch
-size_t NSamplesDevice(DMatrixProxy *proxy)
+std::size_t NSamplesDevice(DMatrixProxy *)
 #if defined(XGBOOST_USE_CUDA)
 ;  // NOLINT
 #else
@@ -28,7 +28,7 @@ size_t NSamplesDevice(DMatrixProxy *proxy)
   return 0;
 }
 #endif
-size_t NFeaturesDevice(DMatrixProxy *proxy)
+std::size_t NFeaturesDevice(DMatrixProxy *)
 #if defined(XGBOOST_USE_CUDA)
 ;  // NOLINT
 #else
@@ -189,7 +189,7 @@ BatchSet<GHistIndexMatrix> SparsePageDMatrix::GetGradientIndex(const BatchParam
 }
 
 #if !defined(XGBOOST_USE_CUDA)
-BatchSet<EllpackPage> SparsePageDMatrix::GetEllpackBatches(const BatchParam& param) {
+BatchSet<EllpackPage> SparsePageDMatrix::GetEllpackBatches(const BatchParam &) {
   common::AssertGPUSupport();
   auto begin_iter = BatchIterator<EllpackPage>(ellpack_page_source_);
   return BatchSet<EllpackPage>(BatchIterator<EllpackPage>(begin_iter));

src/data/sparse_page_source.cu

@@ -9,11 +9,11 @@ namespace xgboost {
 namespace data {
 
 namespace detail {
-size_t NSamplesDevice(DMatrixProxy *proxy) {
+std::size_t NSamplesDevice(DMatrixProxy *proxy) {
   return Dispatch(proxy, [](auto const &value) { return value.NumRows(); });
 }
 
-size_t NFeaturesDevice(DMatrixProxy *proxy) {
+std::size_t NFeaturesDevice(DMatrixProxy *proxy) {
   return Dispatch(proxy, [](auto const &value) { return value.NumCols(); });
 }
 }  // namespace detail