Restore clang tidy test. (#8861)

tests/cpp/common/test_charconv.cc

@@ -128,7 +128,7 @@ TEST(Ryu, Regression) {
   TestRyu("2E2", 200.0f);
   TestRyu("3.3554432E7", 3.3554432E7f);
 
-  static_assert(1.1920929E-7f == std::numeric_limits<float>::epsilon(), "");
+  static_assert(1.1920929E-7f == std::numeric_limits<float>::epsilon());
   TestRyu("1.1920929E-7", std::numeric_limits<float>::epsilon());
 }
 

tests/cpp/common/test_group_data.cc

@@ -43,8 +43,8 @@ TEST(GroupData, ParallelGroupBuilder) {
   builder2.Push(2, Entry(0, 4), 0);
   builder2.Push(2, Entry(1, 5), 0);
 
-  expected_data.emplace_back(Entry(0, 4));
-  expected_data.emplace_back(Entry(1, 5));
+  expected_data.emplace_back(0, 4);
+  expected_data.emplace_back(1, 5);
   expected_offsets.emplace_back(6);
 
   EXPECT_EQ(data, expected_data);

tests/cpp/common/test_hist_util.cu

@@ -143,7 +143,7 @@ void TestMixedSketch() {
   size_t n_samples = 1000, n_features = 2, n_categories = 3;
   std::vector<float> data(n_samples * n_features);
   SimpleLCG gen;
-  SimpleRealUniformDistribution<float> cat_d{0.0f, float(n_categories)};
+  SimpleRealUniformDistribution<float> cat_d{0.0f, static_cast<float>(n_categories)};
   SimpleRealUniformDistribution<float> num_d{0.0f, 3.0f};
   for (size_t i = 0; i < n_samples * n_features; ++i) {
     if (i % 2 == 0) {

tests/cpp/common/test_intrusive_ptr.cc

@@ -13,9 +13,9 @@ class NotCopyConstructible {
   NotCopyConstructible(NotCopyConstructible&& that) = default;
 };
 static_assert(
-    !std::is_trivially_copy_constructible<NotCopyConstructible>::value, "");
+    !std::is_trivially_copy_constructible<NotCopyConstructible>::value);
 static_assert(
-    !std::is_trivially_copy_assignable<NotCopyConstructible>::value, "");
+    !std::is_trivially_copy_assignable<NotCopyConstructible>::value);
 
 class ForIntrusivePtrTest {
  public:

tests/cpp/common/test_linalg.cc

@@ -1,5 +1,5 @@
-/*!
- * Copyright 2021 by XGBoost Contributors
+/**
+ * Copyright 2021-2023 by XGBoost Contributors
  */
 #include <gtest/gtest.h>
 #include <xgboost/context.h>
@@ -108,7 +108,7 @@ TEST(Linalg, TensorView) {
     // for Slice.
     auto t = MakeTensorView(data, {2, 3, 4}, 0);
     auto s = t.Slice(1, 2, All());
-    static_assert(decltype(s)::kDimension == 1, "");
+    static_assert(decltype(s)::kDimension == 1);
   }
   {
     auto t = MakeTensorView(data, {2, 3, 4}, 0);
@@ -121,7 +121,7 @@ TEST(Linalg, TensorView) {
     // range slice
     auto t = MakeTensorView(data, {2, 3, 4}, 0);
     auto s = t.Slice(linalg::All(), linalg::Range(1, 3), 2);
-    static_assert(decltype(s)::kDimension == 2, "");
+    static_assert(decltype(s)::kDimension == 2);
     std::vector<double> sol{6, 10, 18, 22};
     auto k = 0;
     for (size_t i = 0; i < s.Shape(0); ++i) {
@@ -136,7 +136,7 @@ TEST(Linalg, TensorView) {
     // range slice
     auto t = MakeTensorView(data, {2, 3, 4}, 0);
     auto s = t.Slice(1, linalg::Range(1, 3), linalg::Range(1, 3));
-    static_assert(decltype(s)::kDimension == 2, "");
+    static_assert(decltype(s)::kDimension == 2);
     std::vector<double> sol{17, 18, 21, 22};
     auto k = 0;
     for (size_t i = 0; i < s.Shape(0); ++i) {
@@ -151,7 +151,7 @@ TEST(Linalg, TensorView) {
     // same as no slice.
     auto t = MakeTensorView(data, {2, 3, 4}, 0);
     auto s = t.Slice(linalg::All(), linalg::Range(0, 3), linalg::Range(0, 4));
-    static_assert(decltype(s)::kDimension == 3, "");
+    static_assert(decltype(s)::kDimension == 3);
     auto all = t.Slice(linalg::All(), linalg::All(), linalg::All());
     for (size_t i = 0; i < s.Shape(0); ++i) {
       for (size_t j = 0; j < s.Shape(1); ++j) {

tests/cpp/common/test_linalg.cu

@@ -1,5 +1,5 @@
-/*!
- * Copyright 2021-2022 by XGBoost Contributors
+/**
+ * Copyright 2021-2023 by XGBoost Contributors
  */
 #include <gtest/gtest.h>
 
@@ -60,7 +60,7 @@ void TestSlice() {
   dh::LaunchN(1, [=] __device__(size_t) {
     auto s = t.Slice(linalg::All(), linalg::Range(0, 3), linalg::Range(0, 4));
     auto all = t.Slice(linalg::All(), linalg::All(), linalg::All());
-    static_assert(decltype(s)::kDimension == 3, "");
+    static_assert(decltype(s)::kDimension == 3);
     for (size_t i = 0; i < s.Shape(0); ++i) {
       for (size_t j = 0; j < s.Shape(1); ++j) {
         for (size_t k = 0; k < s.Shape(2); ++k) {

tests/cpp/common/test_span.cc

@@ -522,9 +522,9 @@ TEST(Span, Empty) {
 TEST(SpanDeathTest, Empty) {
   std::vector<float> data(1, 0);
   ASSERT_TRUE(data.data());
-  Span<float> s{data.data(), Span<float>::index_type(0)};  // ok to define 0 size span.
+  // ok to define 0 size span.
+  Span<float> s{data.data(), static_cast<Span<float>::index_type>(0)};
   EXPECT_DEATH(s[0], "");  // not ok to use it.
 }
-
 }  // namespace common
 }  // namespace xgboost