Fix compilation with GCC9 and MSVC 2019 with CMAKE_CXX_STANDARD=20

.travis.yml

@@ -50,12 +50,18 @@ env:
   - JOB_NAME=examples # 5-7 minutes
   - JOB_NAME=cmake # 3-5 minutes
   - JOB_NAME=cmake-gcc8 # 3-5 minutes
+  - JOB_NAME=cmake-gcc9 # 3-5 minutes
+  - JOB_NAME=cmake-gcc9-c++20 # 3-5 minutes
   - JOB_NAME=cmake-mingw # 3 minutes
 
 matrix:
   exclude:
   - os: osx
     env: JOB_NAME=cmake-gcc8
+  - os: osx
+    env: JOB_NAME=cmake-gcc9
+  - os: osx
+    env: JOB_NAME=cmake-gcc9-c++20
   - os: osx
     env: JOB_NAME=cmake-mingw
   - os: osx
@@ -157,7 +163,22 @@ matrix:
     os: linux
     arch: ppc64le
     env: JOB_NAME=cmake-gcc8
-
+  - if: type = pull_request
+    os : linux
+    arch: arm64
+    env: JOB_NAME=cmake-gcc9
+  - if: type = pull_request
+    os: linux
+    arch: ppc64le
+    env: JOB_NAME=cmake-gcc9
+  - if: type = pull_request
+    os : linux
+    arch: arm64
+    env: JOB_NAME=cmake-gcc9-c++20
+  - if: type = pull_request
+    os: linux
+    arch: ppc64le
+    env: JOB_NAME=cmake-gcc9-c++20
 install:
   - if [ "${TRAVIS_OS_NAME}" == osx ]; then
       PATH=$PATH:/usr/local/opt/ccache/libexec;
@@ -166,6 +187,10 @@ install:
       sudo apt-get install -y g++-8;
       CC=gcc-8 && CXX=g++-8;
     fi
+  - if [ "${JOB_NAME}" == cmake-gcc9 ] || [ "${JOB_NAME}" == cmake-gcc9-c++20 ]; then
+      sudo apt-get install -y g++-9;
+      CC=gcc-9 && CXX=g++-9;
+    fi
   - if [ "${JOB_NAME}" == cmake-mingw ]; then
       sudo apt-get install -y mingw-w64 ;
     fi
@@ -235,7 +260,13 @@ script:
       mkdir build && cd build && cmake -DJNI=1 -DWITH_GFLAGS=OFF .. -DCMAKE_C_COMPILER=x86_64-w64-mingw32-gcc -DCMAKE_CXX_COMPILER=x86_64-w64-mingw32-g++ -DCMAKE_SYSTEM_NAME=Windows && make -j4 rocksdb rocksdbjni
       ;;
     cmake*)
-      mkdir build && cd build && cmake -DJNI=1 .. -DCMAKE_BUILD_TYPE=Release && make -j4 rocksdb rocksdbjni
+      case $JOB_NAME in
+        *-c++20)
+          OPT=-DCMAKE_CXX_STANDARD=20
+          ;;
+      esac
+
+      mkdir build && cd build && cmake -DJNI=1 .. -DCMAKE_BUILD_TYPE=Release $OPT && make -j4 rocksdb rocksdbjni
       ;;
     esac
 notifications:

CMakeLists.txt

@@ -83,6 +83,10 @@ else()
   option(WITH_FOLLY_DISTRIBUTED_MUTEX "build with folly::DistributedMutex" OFF)
 endif()
 
+if( NOT DEFINED CMAKE_CXX_STANDARD )
+  set(CMAKE_CXX_STANDARD 11)
+endif()
+
 include(CMakeDependentOption)
 CMAKE_DEPENDENT_OPTION(WITH_GFLAGS "build with GFlags" ON
   "NOT MSVC;NOT MINGW" OFF)
@@ -191,7 +195,6 @@ else()
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-format -fno-asynchronous-unwind-tables")
     add_definitions(-D_POSIX_C_SOURCE=1)
   endif()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
   if(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-omit-frame-pointer")
     include(CheckCXXCompilerFlag)
@@ -254,6 +257,7 @@ include(CheckCXXSourceCompiles)
 if(NOT MSVC)
   set(CMAKE_REQUIRED_FLAGS "-msse4.2 -mpclmul")
 endif()
+
 CHECK_CXX_SOURCE_COMPILES("
 #include <cstdint>
 #include <nmmintrin.h>
@@ -386,7 +390,15 @@ if(MSVC)
     message(STATUS "Debug optimization is enabled")
     set(CMAKE_CXX_FLAGS_DEBUG "/Oxt")
   else()
-    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Od /RTC1 /Gm")
+    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Od /RTC1")
+
+    # Minimal Build is deprecated after MSVC 2015
+    if( MSVC_VERSION GREATER 1900 )
+      set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Gm-")
+    else()
+      set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Gm")
+    endif()
+
   endif()
   if(WITH_RUNTIME_DEBUG)
     set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /${RUNTIME_LIBRARY}d")
@@ -495,6 +507,45 @@ if(HAVE_AUXV_GETAUXVAL)
   add_definitions(-DROCKSDB_AUXV_GETAUXVAL_PRESENT)
 endif()
 
+# Workaround to get c++ std version option coming from CMAKE_CXX_STANDARD for try_compile 
+include(CxxFlags)
+get_cxx_std_flags(CMAKE_REQUIRED_FLAGS)
+
+CHECK_CXX_SOURCE_COMPILES("
+template< typename F >
+int apply(F f) {
+  return f();
+}
+
+struct test {
+  test() : value_(0) {}
+
+  int lambda() {
+    return apply([=]() {
+      return value_;
+    });
+  }
+
+  int value_;
+};
+
+int main() {
+  test t;
+  return t.lambda();
+}
+" HAVE_IMPLICIT_THIS_LAMBDA_CAPTURE
+)
+
+unset(CMAKE_REQUIRED_FLAGS)
+
+if(HAVE_IMPLICIT_THIS_LAMBDA_CAPTURE)
+  set(ROCKSDB_THIS_LAMBDA_CAPTURE "=")
+else()
+  set(ROCKSDB_THIS_LAMBDA_CAPTURE "=, this")
+endif()
+add_definitions(-DROCKSDB_THIS_LAMBDA_CAPTURE=${ROCKSDB_THIS_LAMBDA_CAPTURE})
+
+
 include_directories(${PROJECT_SOURCE_DIR})
 include_directories(${PROJECT_SOURCE_DIR}/include)
 include_directories(SYSTEM ${PROJECT_SOURCE_DIR}/third-party/gtest-1.8.1/fused-src)
@@ -848,7 +899,6 @@ if(ROCKSDB_BUILD_SHARED)
                           LINKER_LANGUAGE CXX
                           VERSION ${rocksdb_VERSION}
                           SOVERSION ${rocksdb_VERSION_MAJOR}
-                          CXX_STANDARD 11
                           OUTPUT_NAME "rocksdb")
   endif()
 endif()
@@ -941,7 +991,7 @@ if(WITH_TESTS)
   add_library(testharness STATIC
   test_util/testharness.cc)
   target_link_libraries(testharness gtest)
-
+                            
   set(TESTS
         cache/cache_test.cc
         cache/lru_cache_test.cc
@@ -1125,7 +1175,7 @@ if(WITH_TESTS)
         PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD_RELEASE 1
         EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
         EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
-        )
+  )
 
   foreach(sourcefile ${TESTS})
       get_filename_component(exename ${sourcefile} NAME_WE)
@@ -1135,7 +1185,7 @@ if(WITH_TESTS)
         EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
         EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
         OUTPUT_NAME ${exename}${ARTIFACT_SUFFIX}
-        )
+      )
       target_link_libraries(${CMAKE_PROJECT_NAME}_${exename}${ARTIFACT_SUFFIX} testutillib${ARTIFACT_SUFFIX} testharness gtest ${ROCKSDB_LIB})
       if(NOT "${exename}" MATCHES "db_sanity_test")
         add_test(NAME ${exename} COMMAND ${exename}${ARTIFACT_SUFFIX})
@@ -1215,4 +1265,4 @@ if(WITH_TOOLS)
   add_subdirectory(db_stress_tool)
   add_custom_target(tools
     DEPENDS ${tool_deps})
-endif()
+endif()

appveyor.yml

@@ -1,6 +1,6 @@
 version: 1.0.{build}
 
-image: Visual Studio 2017
+image: Visual Studio 2019
 
 environment:
   JAVA_HOME: C:\Program Files\Java\jdk1.8.0
@@ -24,6 +24,15 @@ environment:
     - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
       CMAKE_GENERATOR: Visual Studio 15 Win64
       DEV_ENV: C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\devenv.com
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      CMAKE_GENERATOR: Visual Studio 16
+      CMAKE_PLATEFORM_NAME: x64
+      DEV_ENV: C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\IDE\devenv.com
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      CMAKE_GENERATOR: Visual Studio 16
+      CMAKE_PLATEFORM_NAME: x64
+      CMAKE_OPT: -DCMAKE_CXX_STANDARD=20
+      DEV_ENV: C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\IDE\devenv.com
 
 install:
   - md %THIRDPARTY_HOME%
@@ -34,7 +43,8 @@ install:
   - cd snappy-1.1.7
   - mkdir build
   - cd build
-  - cmake -G "%CMAKE_GENERATOR%" ..
+  - if DEFINED CMAKE_PLATEFORM_NAME (set "PLATEFORM_OPT=-A %CMAKE_PLATEFORM_NAME%")
+  - cmake .. -G "%CMAKE_GENERATOR%" %PLATEFORM_OPT%
   - msbuild Snappy.sln /p:Configuration=Debug /p:Platform=x64
   - msbuild Snappy.sln /p:Configuration=Release /p:Platform=x64
   - echo "Building LZ4 dependency..."
@@ -57,7 +67,8 @@ install:
 before_build:
   - md %APPVEYOR_BUILD_FOLDER%\build
   - cd %APPVEYOR_BUILD_FOLDER%\build
-  - cmake -G "%CMAKE_GENERATOR%" -DCMAKE_BUILD_TYPE=Debug -DOPTDBG=1 -DPORTABLE=1 -DSNAPPY=1 -DLZ4=1 -DZSTD=1 -DXPRESS=1 -DJNI=1 ..
+  - if DEFINED CMAKE_PLATEFORM_NAME (set "PLATEFORM_OPT=-A %CMAKE_PLATEFORM_NAME%")
+  - cmake .. -G "%CMAKE_GENERATOR%" %PLATEFORM_OPT% %CMAKE_OPT% -DCMAKE_BUILD_TYPE=Debug -DOPTDBG=1 -DPORTABLE=1 -DSNAPPY=1 -DLZ4=1 -DZSTD=1 -DXPRESS=1 -DJNI=1
   - cd ..
 
 build:

build_tools/build_detect_platform

@@ -684,6 +684,29 @@ EOF
   fi
 fi
 
+
+$CXX $PLATFORM_CXXFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null <<EOF
+struct test {
+  test() : value_(0) {}
+
+  int lambda() {
+    return [=]() { return value_; }();
+  }
+
+  int value_;
+};
+
+int main() {
+  test t;
+  return t.lambda();
+}
+EOF
+if [ "$?" = 0 ]; then
+  COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_THIS_LAMBDA_CAPTURE=\"=\""
+else
+  COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_THIS_LAMBDA_CAPTURE=\"=, this\""
+fi
+
 if [ "$FBCODE_BUILD" != "true" -a "$PLATFORM" = OS_LINUX ]; then
   $CXX $COMMON_FLAGS $PLATFORM_SHARED_CFLAGS -x c++ -c - -o test_dl.o 2>/dev/null <<EOF
   void dummy_func() {}

cmake/modules/CxxFlags.cmake

@@ -0,0 +1,7 @@
+macro(get_cxx_std_flags FLAGS_VARIABLE)
+  if( CMAKE_CXX_STANDARD_REQUIRED )
+    set(${FLAGS_VARIABLE} ${CMAKE_CXX${CMAKE_CXX_STANDARD}_STANDARD_COMPILE_OPTION})
+  else()
+    set(${FLAGS_VARIABLE} ${CMAKE_CXX${CMAKE_CXX_STANDARD}_EXTENSION_COMPILE_OPTION})
+  endif()
+endmacro()

db/db_bloom_filter_test.cc

@@ -12,6 +12,7 @@
 #include "rocksdb/perf_context.h"
 #include "table/block_based/filter_policy_internal.h"
 
+
 namespace ROCKSDB_NAMESPACE {
 
 namespace {
@@ -1343,8 +1344,9 @@ TEST_F(DBBloomFilterTest, OptimizeFiltersForHits) {
   for (int i = 0; i < numkeys; i += 2) {
     keys.push_back(i);
   }
-  std::random_shuffle(std::begin(keys), std::end(keys));
-
+  std::random_device rng;
+  std::mt19937 urng(rng());
+  std::shuffle(std::begin(keys), std::end(keys), urng);
   int num_inserted = 0;
   for (int key : keys) {
     ASSERT_OK(Put(1, Key(key), "val"));

db/db_compaction_test.cc

@@ -4762,7 +4762,9 @@ TEST_P(CompactionPriTest, Test) {
   for (int i = 0; i < kNKeys; i++) {
     keys[i] = i;
   }
-  std::random_shuffle(std::begin(keys), std::end(keys));
+  std::random_device rng;
+  std::mt19937 urng(rng());
+  std::shuffle(std::begin(keys), std::end(keys), urng);
 
   for (int i = 0; i < kNKeys; i++) {
     ASSERT_OK(Put(Key(keys[i]), RandomString(&rnd, 102)));

db/db_dynamic_level_test.cc

@@ -50,7 +50,9 @@ TEST_F(DBTestDynamicLevel, DynamicLevelMaxBytesBase) {
       keys[i] = i;
     }
     if (ordered_insert == 0) {
-      std::random_shuffle(std::begin(keys), std::end(keys));
+      std::random_device rng;
+      std::mt19937 urng(rng());
+      std::shuffle(std::begin(keys), std::end(keys), urng);
     }
     for (int max_background_compactions = 1; max_background_compactions < 4;
          max_background_compactions += 2) {

db/db_test.cc

@@ -1421,7 +1421,9 @@ TEST_F(DBTest, ApproximateSizesMemTable) {
     keys[i * 3 + 1] = i * 5 + 1;
     keys[i * 3 + 2] = i * 5 + 2;
   }
-  std::random_shuffle(std::begin(keys), std::end(keys));
+  std::random_device rng;
+  std::mt19937 urng(rng());
+  std::shuffle(std::begin(keys), std::end(keys), urng);
 
   for (int i = 0; i < N * 3; i++) {
     ASSERT_OK(Put(Key(keys[i] + 1000), RandomString(&rnd, 1024)));
@@ -4530,7 +4532,9 @@ TEST_F(DBTest, DynamicLevelCompressionPerLevel) {
   for (int i = 0; i < kNKeys; i++) {
     keys[i] = i;
   }
-  std::random_shuffle(std::begin(keys), std::end(keys));
+  std::random_device rng;
+  std::mt19937 urng(rng());
+  std::shuffle(std::begin(keys), std::end(keys), urng);
 
   Random rnd(301);
   Options options;
@@ -4613,7 +4617,9 @@ TEST_F(DBTest, DynamicLevelCompressionPerLevel2) {
   for (int i = 0; i < kNKeys; i++) {
     keys[i] = i;
   }
-  std::random_shuffle(std::begin(keys), std::end(keys));
+  std::random_device rng;
+  std::mt19937 urng(rng());
+  std::shuffle(std::begin(keys), std::end(keys), urng);
 
   Random rnd(301);
   Options options;

db/perf_context_test.cc

@@ -251,7 +251,9 @@ void ProfileQueries(bool enabled_time = false) {
   }
 
   if (FLAGS_random_key) {
-    std::random_shuffle(keys.begin(), keys.end());
+    std::random_device rng;
+    std::mt19937 urng(rng());
+    std::shuffle(std::begin(keys), std::end(keys), urng);
   }
 #ifndef NDEBUG
   ThreadStatusUtil::TEST_SetStateDelay(ThreadStatus::STATE_MUTEX_WAIT, 1U);
@@ -524,7 +526,9 @@ TEST_F(PerfContextTest, SeekKeyComparison) {
   }
 
   if (FLAGS_random_key) {
-    std::random_shuffle(keys.begin(), keys.end());
+    std::random_device rng;
+    std::mt19937 urng(rng());
+    std::shuffle(std::begin(keys), std::end(keys), urng);
   }
 
   HistogramImpl hist_put_time;

include/rocksdb/file_system.h

@@ -105,6 +105,8 @@ struct FileOptions : EnvOptions {
 
   FileOptions(const FileOptions& opts)
     : EnvOptions(opts), io_options(opts.io_options) {}
+
+  FileOptions& operator=(const FileOptions& opts) = default;
 };
 
 // A structure to pass back some debugging information from the FileSystem