C++14 for xgboost (#5664)

CMakeLists.txt

@@ -112,7 +112,7 @@ endif (USE_OPENMP)
 msvc_use_static_runtime()
 add_subdirectory(${xgboost_SOURCE_DIR}/dmlc-core)
 set_target_properties(dmlc PROPERTIES
-  CXX_STANDARD 11
+  CXX_STANDARD 14
   CXX_STANDARD_REQUIRED ON
   POSITION_INDEPENDENT_CODE ON)
 list(APPEND LINKED_LIBRARIES_PRIVATE dmlc)
@@ -195,7 +195,7 @@ target_link_libraries(runxgboost PRIVATE ${LINKED_LIBRARIES_PRIVATE})
 set_target_properties(
   runxgboost PROPERTIES
   OUTPUT_NAME xgboost
-  CXX_STANDARD 11
+  CXX_STANDARD 14
   CXX_STANDARD_REQUIRED ON)
 #-- End CLI for xgboost
 

Makefile

@@ -44,7 +44,7 @@ export CXX = g++
 endif
 endif
 
-export CFLAGS= -DDMLC_LOG_CUSTOMIZE=1 -std=c++11 -Wall -Wno-unknown-pragmas -Iinclude $(ADD_CFLAGS)
+export CFLAGS= -DDMLC_LOG_CUSTOMIZE=1 -std=c++14 -Wall -Wno-unknown-pragmas -Iinclude $(ADD_CFLAGS)
 CFLAGS += -I$(DMLC_CORE)/include -I$(RABIT)/include -I$(GTEST_PATH)/include
 
 ifeq ($(TEST_COVER), 1)

R-package/CMakeLists.txt

@@ -25,7 +25,7 @@ target_include_directories(xgboost-r
   ${PROJECT_SOURCE_DIR}/rabit/include)
 set_target_properties(
   xgboost-r PROPERTIES
-  CXX_STANDARD 11
+  CXX_STANDARD 14
   CXX_STANDARD_REQUIRED ON
   POSITION_INDEPENDENT_CODE ON)
 

R-package/DESCRIPTION

@@ -64,4 +64,4 @@ Imports:
     magrittr (>= 1.5),
     stringi (>= 0.5.2)
 RoxygenNote: 7.1.0
-SystemRequirements: GNU make, C++11
+SystemRequirements: GNU make, C++14

R-package/src/Makevars.in

@@ -3,7 +3,7 @@ PKGROOT=../../
 ENABLE_STD_THREAD=1
 # _*_ mode: Makefile; _*_
 
-CXX_STD = CXX11
+CXX_STD = CXX14
 
 XGB_RFLAGS = -DXGBOOST_STRICT_R_MODE=1 -DDMLC_LOG_BEFORE_THROW=0\
            -DDMLC_ENABLE_STD_THREAD=$(ENABLE_STD_THREAD) -DDMLC_DISABLE_STDIN=1\

R-package/src/Makevars.win

@@ -15,7 +15,7 @@ xgblib:
 	cp -r ../../include .
 	cp -r ../../amalgamation .
 
-CXX_STD = CXX11
+CXX_STD = CXX14
 
 XGB_RFLAGS = -DXGBOOST_STRICT_R_MODE=1 -DDMLC_LOG_BEFORE_THROW=0\
            -DDMLC_ENABLE_STD_THREAD=$(ENABLE_STD_THREAD) -DDMLC_DISABLE_STDIN=1\

jvm-packages/CMakeLists.txt

@@ -14,7 +14,7 @@ target_include_directories(xgboost4j
 set_output_directory(xgboost4j ${PROJECT_SOURCE_DIR}/lib)
 set_target_properties(
   xgboost4j PROPERTIES
-  CXX_STANDARD 11
+  CXX_STANDARD 14
   CXX_STANDARD_REQUIRED ON)
 target_link_libraries(xgboost4j
   PRIVATE

src/CMakeLists.txt

@@ -14,7 +14,6 @@ if (USE_CUDA)
     $<$<COMPILE_LANGUAGE:CUDA>:--expt-extended-lambda>
     $<$<COMPILE_LANGUAGE:CUDA>:--expt-relaxed-constexpr>
     $<$<COMPILE_LANGUAGE:CUDA>:-lineinfo>
-    $<$<AND:$<NOT:$<CXX_COMPILER_ID:MSVC>>,$<COMPILE_LANGUAGE:CUDA>>:--std=c++11>
     $<$<COMPILE_LANGUAGE:CUDA>:${GEN_CODE}>)
 
   if (USE_NCCL)
@@ -45,6 +44,8 @@ if (USE_CUDA)
   endif (HIDE_CXX_SYMBOLS)
 
   set_target_properties(objxgboost PROPERTIES
+    CUDA_STANDARD 14
+    CUDA_STANDARD_REQUIRED ON
     CUDA_SEPARABLE_COMPILATION OFF)
 else (USE_CUDA)
   add_library(objxgboost OBJECT ${CPU_SOURCES} ${PLUGINS_SOURCES})
@@ -71,7 +72,7 @@ endif (MSVC)
 
 set_target_properties(objxgboost PROPERTIES
   POSITION_INDEPENDENT_CODE ON
-  CXX_STANDARD 11
+  CXX_STANDARD 14
   CXX_STANDARD_REQUIRED ON)
 target_compile_definitions(objxgboost
   PRIVATE

src/common/column_matrix.h

@@ -35,6 +35,8 @@ class Column {
         index_(index),
         index_base_(index_base) {}
 
+  virtual ~Column() = default;
+
   uint32_t GetGlobalBinIdx(size_t idx) const {
     return index_base_ + static_cast<uint32_t>(index_[idx]);
   }

src/objective/rank_obj.cu

@@ -314,7 +314,7 @@ class NDCGLambdaWeightComputer
       for (size_t i = 0; i < sorted_list.size(); ++i) {
         labels[i] = sorted_list[i].label;
       }
-      std::stable_sort(labels.begin(), labels.end(), std::greater<bst_float>());
+      std::stable_sort(labels.begin(), labels.end(), std::greater<>());
       IDCG = ComputeGroupDCGWeight(&labels[0], labels.size());
     }
     if (IDCG == 0.0) {

src/tree/updater_histmaker.cc

@@ -699,7 +699,7 @@ class GlobalProposalHistMaker: public CQHistMaker {
       this->work_set_.insert(this->work_set_.end(), this->fsplit_set_.begin(),
                              this->fsplit_set_.end());
       XGBOOST_PARALLEL_SORT(this->work_set_.begin(), this->work_set_.end(),
-                            std::less<decltype(this->work_set_)::value_type>{});
+                            std::less<>{});
       this->work_set_.resize(
           std::unique(this->work_set_.begin(), this->work_set_.end()) - this->work_set_.begin());
 

tests/ci_build/tidy.py

@@ -124,8 +124,8 @@ class ClangTidy(object):
                 if pos != -1:
                     converted_components.append(
                         '--cuda-gpu-arch=sm_' + capability)
-            elif components[i].find('--std=c++11') != -1:
+            elif components[i].find('--std=c++14') != -1:
-                converted_components.append('-std=c++11')
+                converted_components.append('-std=c++14')
             elif components[i].startswith('-isystem='):
                 converted_components.extend(components[i].split('='))
             else:

tests/cpp/CMakeLists.txt

@@ -24,7 +24,6 @@ if (USE_CUDA)
     $<$<COMPILE_LANGUAGE:CUDA>:--expt-extended-lambda>
     $<$<COMPILE_LANGUAGE:CUDA>:--expt-relaxed-constexpr>
     $<$<COMPILE_LANGUAGE:CUDA>:-lineinfo>
-    $<$<AND:$<NOT:$<CXX_COMPILER_ID:MSVC>>,$<COMPILE_LANGUAGE:CUDA>>:--std=c++11>
     $<$<COMPILE_LANGUAGE:CUDA>:-Xcompiler=${OpenMP_CXX_FLAGS}>
     $<$<COMPILE_LANGUAGE:CUDA>:${GEN_CODE}>)
   target_compile_definitions(testxgboost
@@ -48,6 +47,10 @@ if (USE_CUDA)
       $<$<COMPILE_LANGUAGE:CUDA>:-Xcompiler=/utf-8>
     )
   endif (MSVC)
+
+  set_target_properties(testxgboost PROPERTIES
+    CUDA_STANDARD 14
+    CUDA_STANDARD_REQUIRED ON)
 endif (USE_CUDA)
 
 if (MSVC)
@@ -64,7 +67,7 @@ target_include_directories(testxgboost
   ${xgboost_SOURCE_DIR}/rabit/include)
 set_target_properties(
   testxgboost PROPERTIES
-  CXX_STANDARD 11
+  CXX_STANDARD 14
   CXX_STANDARD_REQUIRED ON)
 target_link_libraries(testxgboost
   PRIVATE