Forbid pointer to bool cast.

Author: trivialfis

src/tree/gpu_hist/gradient_based_sampler.cu

@@ -318,9 +318,9 @@ GradientBasedSample ExternalMemoryGradientBasedSampling::Sample(Context const* c
   return {sample_rows, page_.get(), dh::ToSpan(gpair_)};
 }
 
-GradientBasedSampler::GradientBasedSampler(Context const* /*ctx*/, bool is_external_memory,
-                                           size_t n_rows, const BatchParam& batch_param,
-                                           float subsample, int sampling_method) {
+GradientBasedSampler::GradientBasedSampler(Context const* /*ctx*/, size_t n_rows,
+                                           const BatchParam& batch_param, float subsample,
+                                           int sampling_method, bool is_external_memory) {
   // The ctx is kept here for future development of stream-based operations.
   monitor_.Init("gradient_based_sampler");
 

src/tree/gpu_hist/gradient_based_sampler.cuh

@@ -122,8 +122,8 @@ class ExternalMemoryGradientBasedSampling : public SamplingStrategy {
  */
 class GradientBasedSampler {
  public:
-  GradientBasedSampler(Context const* ctx, bool is_external_memory, size_t n_rows,
-                       const BatchParam& batch_param, float subsample, int sampling_method);
+  GradientBasedSampler(Context const* ctx, size_t n_rows, const BatchParam& batch_param,
+                       float subsample, int sampling_method, bool is_external_memory);
 
   /*! \brief Sample from a DMatrix based on the given gradient pairs. */
   GradientBasedSample Sample(Context const* ctx, common::Span<GradientPair> gpair, DMatrix* dmat);

src/tree/updater_gpu_hist.cu

@@ -216,8 +216,8 @@ struct GPUHistMakerDevice {
         column_sampler(column_sampler_seed),
         interaction_constraints(param, n_features),
         batch_param(std::move(_batch_param)) {
-    sampler.reset(new GradientBasedSampler(ctx, is_external_memory, _n_rows, batch_param,
-                                           param.subsample, param.sampling_method));
+    sampler.reset(new GradientBasedSampler(ctx, _n_rows, batch_param, param.subsample,
+                                           param.sampling_method, is_external_memory));
     if (!param.monotone_constraints.empty()) {
       // Copy assigning an empty vector causes an exception in MSVC debug builds
       monotone_constraints = param.monotone_constraints;

tests/cpp/tree/gpu_hist/test_gradient_based_sampler.cu

@@ -39,7 +39,8 @@ void VerifySampling(size_t page_size,
     EXPECT_NE(page->n_rows, kRows);
   }
 
-  GradientBasedSampler sampler(&ctx, page, kRows, param, subsample, sampling_method);
+  GradientBasedSampler sampler(&ctx, kRows, param, subsample, sampling_method,
+                               !fixed_size_sampling);
   auto sample = sampler.Sample(&ctx, gpair.DeviceSpan(), dmat.get());
 
   if (fixed_size_sampling) {
@@ -93,7 +94,7 @@ TEST(GradientBasedSampler, NoSamplingExternalMemory) {
   auto page = (*dmat->GetBatches<EllpackPage>(&ctx, param).begin()).Impl();
   EXPECT_NE(page->n_rows, kRows);
 
-  GradientBasedSampler sampler(&ctx, page, kRows, param, kSubsample, TrainParam::kUniform);
+  GradientBasedSampler sampler(&ctx, kRows, param, kSubsample, TrainParam::kUniform, true);
   auto sample = sampler.Sample(&ctx, gpair.DeviceSpan(), dmat.get());
   auto sampled_page = sample.page;
   EXPECT_EQ(sample.sample_rows, kRows);
@@ -141,7 +142,8 @@ TEST(GradientBasedSampler, GradientBasedSampling) {
   constexpr size_t kPageSize = 0;
   constexpr float kSubsample = 0.8;
   constexpr int kSamplingMethod = TrainParam::kGradientBased;
-  VerifySampling(kPageSize, kSubsample, kSamplingMethod);
+  constexpr bool kFixedSizeSampling = true;
+  VerifySampling(kPageSize, kSubsample, kSamplingMethod, kFixedSizeSampling);
 }
 
 TEST(GradientBasedSampler, GradientBasedSamplingExternalMemory) {