Require C++17 (facebook#9481)

Summary:
Drop support for some old compilers by requiring C++17 standard
(or higher). See facebook#9388

First modification based on this is to remove some conditional compilation in slice.h (also
better for ODR)

Also in this PR:
* Fix some Makefile formatting that seems to affect ASSERT_STATUS_CHECKED config in
some cases
* Add c_test to NON_PARALLEL_TEST in Makefile
* Fix a clang-analyze reported "potential leak" in lru_cache_test
* Better "compatibility" definition of DEFINE_uint32 for old versions of gflags
* Fix a linking problem with shared libraries in Makefile (`./random_test: error while loading shared libraries: librocksdb.so.6.29: cannot open shared object file: No such file or directory`)
* Always set ROCKSDB_SUPPORT_THREAD_LOCAL and use thread_local (from C++11)
  * TODO in later PR: clean up that obsolete flag
* Fix a cosmetic typo in c.h (facebook#9488)

Pull Request resolved: facebook#9481

Test Plan:
CircleCI config substantially updated.

* Upgrade to latest Ubuntu images for each release
* Generally prefer Ubuntu 20, but keep a couple Ubuntu 16 builds with oldest supported
compilers, to ensure compatibility
* Remove .circleci/cat_ignore_eagain except for Ubuntu 16 builds, because this is to work
around a kernel bug that should not affect anything but Ubuntu 16.
* Remove designated gcc-9 build, because the default linux build now uses GCC 9 from
Ubuntu 20.
* Add some `apt-key add` to fix some apt "couldn't be verified" errors
* Generally drop SKIP_LINK=1; work-around no longer needed
* Generally `add-apt-repository` before `apt-get update` as manual testing indicated the
reverse might not work.

Travis:
* Use gcc-7 by default (remove specific gcc-7 and gcc-4.8 builds)
* TODO in later PR: fix s390x "Assembler messages: Error: invalid switch -march=z14" failure

AppVeyor:
* Completely dropped because we are dropping VS2015 support and CircleCI covers
VS >= 2017

Also local testing with old gflags (out of necessity when using ROCKSDB_NO_FBCODE=1).

Reviewed By: mrambacher

Differential Revision: D33946377

Pulled By: pdillinger

fbshipit-source-id: ae077c823905b45370a26c0103ada119459da6c1

.travis.yml

@@ -43,29 +43,19 @@ env:
   - JOB_NAME=cmake-gcc9 # 3-5 minutes
   - JOB_NAME=cmake-gcc9-c++20 # 3-5 minutes
   - JOB_NAME=cmake-mingw # 3 minutes
-  - JOB_NAME=make-gcc4.8
   - JOB_NAME=status_checked
 
 matrix:
   exclude:
   - os : linux
     arch: arm64
     env: JOB_NAME=cmake-mingw
-  - os : linux
-    arch: arm64
-    env: JOB_NAME=make-gcc4.8
   - os: linux
     arch: ppc64le
     env: JOB_NAME=cmake-mingw
-  - os: linux
-    arch: ppc64le
-    env: JOB_NAME=make-gcc4.8
   - os: linux
     arch: s390x
     env: JOB_NAME=cmake-mingw
-  - os: linux
-    arch: s390x
-    env: JOB_NAME=make-gcc4.8
   - os: linux
     compiler: clang
   - if: type = pull_request AND commit_message !~ /FULL_CI/
@@ -210,6 +200,7 @@ matrix:
     env: JOB_NAME=status_checked
 
 install:
+  -  CC=gcc-7 && CXX=g++-7
   - if [ "${JOB_NAME}" == cmake-gcc8 ]; then
       sudo apt-get install -y g++-8 || exit $?;
       CC=gcc-8 && CXX=g++-8;
@@ -221,9 +212,8 @@ install:
   - if [ "${JOB_NAME}" == cmake-mingw ]; then
       sudo apt-get install -y mingw-w64 || exit $?;
     fi
-  - if [ "${JOB_NAME}" == make-gcc4.8 ]; then
-      sudo apt-get install -y g++-4.8 || exit $?;
-      CC=gcc-4.8 && CXX=g++-4.8;
+  - if [ "${CXX}" == "g++-7" ]; then
+      sudo apt-get install -y g++-7 || exit $?;
     fi
   - |
     if [[ "${JOB_NAME}" == cmake* ]]; then
@@ -293,9 +283,6 @@ script:
 
       mkdir build && cd build && cmake -DCMAKE_BUILD_TYPE=Release -DWITH_TESTS=0 -DWITH_GFLAGS=0 -DWITH_BENCHMARK_TOOLS=0 -DWITH_TOOLS=0 -DWITH_CORE_TOOLS=1 .. && make -j4 && cd  .. && rm -rf build && mkdir build && cd build && cmake -DJNI=1 .. -DCMAKE_BUILD_TYPE=Release $OPT && make -j4 rocksdb rocksdbjni
       ;;
-    make-gcc4.8)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 SKIP_LINK=1 make -j4 all && [ "Linking broken because libgflags compiled with newer ABI" ]
-      ;;
     status_checked)
       OPT=-DTRAVIS LIB_MODE=shared V=1 ASSERT_STATUS_CHECKED=1 make -j4 check_some
       ;;

CMakeLists.txt

@@ -14,7 +14,7 @@
 #        cd build
 # 3. Run cmake to generate project files for Windows, add more options to enable required third-party libraries.
 #    See thirdparty.inc for more information.
-#        sample command: cmake -G "Visual Studio 15 Win64" -DCMAKE_BUILD_TYPE=Release -DWITH_GFLAGS=1 -DWITH_SNAPPY=1 -DWITH_JEMALLOC=1 -DWITH_JNI=1 ..
+#        sample command: cmake -G "Visual Studio 16 2019" -DCMAKE_BUILD_TYPE=Release -DWITH_GFLAGS=1 -DWITH_SNAPPY=1 -DWITH_JEMALLOC=1 -DWITH_JNI=1 ..
 # 4. Then build the project in debug mode (you may want to add /m[:<N>] flag to run msbuild in <N> parallel threads
 #                                          or simply /m to use all avail cores)
 #        msbuild rocksdb.sln
@@ -27,7 +27,7 @@
 #
 # Linux:
 #
-# 1. Install a recent toolchain such as devtoolset-3 if you're on a older distro. C++11 required.
+# 1. Install a recent toolchain if you're on a older distro. C++17 required (GCC >= 7, Clang >= 5)
 # 2. mkdir build; cd build
 # 3. cmake ..
 # 4. make -j
@@ -92,7 +92,7 @@ else()
 endif()
 
 if( NOT DEFINED CMAKE_CXX_STANDARD )
-  set(CMAKE_CXX_STANDARD 11)
+  set(CMAKE_CXX_STANDARD 17)
 endif()
 
 include(CMakeDependentOption)
@@ -342,7 +342,7 @@ endif()
 
 # Check if -latomic is required or not
 if (NOT MSVC)
-  set(CMAKE_REQUIRED_FLAGS "--std=c++11")
+  set(CMAKE_REQUIRED_FLAGS "--std=c++17")
   CHECK_CXX_SOURCE_COMPILES("
 #include <atomic>
 std::atomic<uint64_t> x(0);
@@ -369,18 +369,8 @@ endif()
 # Reset the required flags
 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
 
-CHECK_CXX_SOURCE_COMPILES("
-#if defined(_MSC_VER) && !defined(__thread)
-#define __thread __declspec(thread)
-#endif
-int main() {
-  static __thread int tls;
-  (void)tls;
-}
-" HAVE_THREAD_LOCAL)
-if(HAVE_THREAD_LOCAL)
-  add_definitions(-DROCKSDB_SUPPORT_THREAD_LOCAL)
-endif()
+# thread_local is part of C++11 and later (TODO: clean up this define)
+add_definitions(-DROCKSDB_SUPPORT_THREAD_LOCAL)
 
 option(WITH_IOSTATS_CONTEXT "Enable IO stats context" ON)
 if (NOT WITH_IOSTATS_CONTEXT)

HISTORY.md

@@ -5,6 +5,7 @@
 * Fixed more cases of EventListener::OnTableFileCreated called with OK status, file_size==0, and no SST file kept. Now the status is Aborted.
 
 ### Public API changes
+* Require C++17 compatible compiler (GCC >= 7, Clang >= 5, Visual Studio >= 2017). See #9388.
 * Remove HDFS support from main repo.
 * Remove librados support from main repo.
 * Remove obsolete backupable_db.h and type alias `BackupableDBOptions`. Use backup_engine.h and `BackupEngineOptions`. Similar renamings are in the C and Java APIs.

INSTALL.md

@@ -6,7 +6,7 @@ than release mode.
 
 RocksDB's library should be able to compile without any dependency installed,
 although we recommend installing some compression libraries (see below).
-We do depend on newer gcc/clang with C++11 support.
+We do depend on newer gcc/clang with C++17 support (GCC >= 7, Clang >= 5).
 
 There are few options when compiling RocksDB:
 
@@ -50,7 +50,7 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
 ## Supported platforms
 
 * **Linux - Ubuntu**
-    * Upgrade your gcc to version at least 4.8 to get C++11 support.
+    * Upgrade your gcc to version at least 7 to get C++17 support.
     * Install gflags. First, try: `sudo apt-get install libgflags-dev`
       If this doesn't work and you're using Ubuntu, here's a nice tutorial:
       (http://askubuntu.com/questions/312173/installing-gflags-12-04)
@@ -62,8 +62,7 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
     * Install zstandard: `sudo apt-get install libzstd-dev`.
 
 * **Linux - CentOS / RHEL**
-    * Upgrade your gcc to version at least 4.8 to get C++11 support:
-      `yum install gcc48-c++`
+    * Upgrade your gcc to version at least 7 to get C++17 support
     * Install gflags:
 
               git clone https://github.com/gflags/gflags.git
@@ -113,11 +112,11 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
               make && sudo make install
 
 * **OS X**:
-    * Install latest C++ compiler that supports C++ 11:
+    * Install latest C++ compiler that supports C++ 17:
         * Update XCode:  run `xcode-select --install` (or install it from XCode App's settting).
         * Install via [homebrew](http://brew.sh/).
             * If you're first time developer in MacOS, you still need to run: `xcode-select --install` in your command line.
-            * run `brew tap homebrew/versions; brew install gcc48 --use-llvm` to install gcc 4.8 (or higher).
+            * run `brew tap homebrew/versions; brew install gcc7 --use-llvm` to install gcc 7 (or higher).
     * run `brew install rocksdb`
 
 * **FreeBSD** (11.01):
@@ -160,7 +159,7 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
 
     * Install the dependencies for RocksDB:
 
-        pkg_add gmake gflags snappy bzip2 lz4 zstd git jdk bash findutils gnuwatch 
+        pkg_add gmake gflags snappy bzip2 lz4 zstd git jdk bash findutils gnuwatch
 
     * Build RocksDB from source:
 
@@ -182,13 +181,13 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
 * **Windows**:
   * For building with MS Visual Studio 13 you will need Update 4 installed.
   * Read and follow the instructions at CMakeLists.txt
-  * Or install via [vcpkg](https://github.com/microsoft/vcpkg) 
+  * Or install via [vcpkg](https://github.com/microsoft/vcpkg)
        * run `vcpkg install rocksdb:x64-windows`
 
 * **AIX 6.1**
     * Install AIX Toolbox rpms with gcc
     * Use these environment variables:
-  
+
              export PORTABLE=1
              export CC=gcc
              export AR="ar -X64"
@@ -199,9 +198,9 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
              export LIBPATH=/opt/freeware/lib
              export JAVA_HOME=/usr/java8_64
              export PATH=/opt/freeware/bin:$PATH
-  
+
 * **Solaris Sparc**
-    * Install GCC 4.8.2 and higher.
+    * Install GCC 7 and higher.
     * Use these environment variables:
 
              export CC=gcc
@@ -210,4 +209,3 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
              export EXTRA_LDFLAGS=-m64
              export PORTABLE=1
              export PLATFORM_LDFLAGS="-static-libstdc++ -static-libgcc"
-

Makefile

@@ -215,7 +215,7 @@ am__v_AR_0 = @echo "  AR      " $@;
 am__v_AR_1 =
 
 AM_LINK = $(AM_V_CCLD)$(CXX) -L. $(patsubst lib%.a, -l%, $(patsubst lib%.$(PLATFORM_SHARED_EXT), -l%, $^)) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
-AM_SHARE = $(AM_V_CCLD) $(CXX) $(PLATFORM_SHARED_LDFLAGS)$@ -L. $(patsubst lib%.$(PLATFORM_SHARED_EXT), -l%, $^) $(LDFLAGS) -o $@
+AM_SHARE = $(AM_V_CCLD) $(CXX) $(PLATFORM_SHARED_LDFLAGS)$@ -L. $(patsubst lib%.$(PLATFORM_SHARED_EXT), -l%, $^) $(EXEC_LDFLAGS) $(LDFLAGS) -o $@
 
 # Detect what platform we're building on.
 # Export some common variables that might have been passed as Make variables
@@ -574,27 +574,29 @@ check-headers: $(HEADER_OK_FILES)
 
 # options_settable_test doesn't pass with UBSAN as we use hack in the test
 ifdef COMPILE_WITH_UBSAN
-        TESTS := $(shell echo $(TESTS) | sed 's/\boptions_settable_test\b//g')
+TESTS := $(shell echo $(TESTS) | sed 's/\boptions_settable_test\b//g')
 endif
 ifdef ASSERT_STATUS_CHECKED
-	# TODO: finish fixing all tests to pass this check
-	TESTS_FAILING_ASC = \
-		c_test \
-		env_test \
-		range_locking_test \
-		testutil_test \
+# TODO: finish fixing all tests to pass this check
+TESTS_FAILING_ASC = \
+	c_test \
+	env_test \
+	range_locking_test \
+	testutil_test \
 
-	# Since we have very few ASC exclusions left, excluding them from
-	# the build is the most convenient way to exclude them from testing
-	TESTS := $(filter-out $(TESTS_FAILING_ASC),$(TESTS))
+# Since we have very few ASC exclusions left, excluding them from
+# the build is the most convenient way to exclude them from testing
+TESTS := $(filter-out $(TESTS_FAILING_ASC),$(TESTS))
 endif
 
 ROCKSDBTESTS_SUBSET ?= $(TESTS)
 
+# c_test - doesn't use gtest
 # env_test - suspicious use of test::TmpDir
 # deletefile_test - serial because it generates giant temporary files in
 #   its various tests. Parallel can fill up your /dev/shm
 NON_PARALLEL_TEST = \
+	c_test \
 	env_test \
 	deletefile_test \
 
@@ -852,7 +854,7 @@ endif
 
 parallel_tests = $(patsubst %,parallel_%,$(PARALLEL_TEST))
 .PHONY: gen_parallel_tests $(parallel_tests)
-$(parallel_tests): $(PARALLEL_TEST)
+$(parallel_tests):
 	$(AM_V_at)TEST_BINARY=$(patsubst parallel_%,%,$@); \
   TEST_NAMES=` \
     (./$$TEST_BINARY --gtest_list_tests || echo "  $${TEST_BINARY}__list_tests_failure") \
@@ -2236,7 +2238,7 @@ rocksdbjavastaticosx_ub: rocksdbjavastaticosx_archs
 	lipo -create -output ./java/target/$(ROCKSDBJNILIB) java/target/librocksdbjni-osx-x86_64.jnilib java/target/librocksdbjni-osx-arm64.jnilib
 	$(MAKE) rocksdbjavastatic_jar
 
-rocksdbjavastaticosx_archs: 
+rocksdbjavastaticosx_archs:
 	$(MAKE) rocksdbjavastaticosx_arch_x86_64
 	$(MAKE) rocksdbjavastaticosx_arch_arm64
 

build_tools/build_detect_platform

@@ -45,11 +45,11 @@ if test -z "$OUTPUT"; then
   exit 1
 fi
 
-# we depend on C++11, but should be compatible with newer standards
+# we depend on C++17, but should be compatible with newer standards
 if [ "$ROCKSDB_CXX_STANDARD" ]; then
   PLATFORM_CXXFLAGS="-std=$ROCKSDB_CXX_STANDARD"
 else
-  PLATFORM_CXXFLAGS="-std=c++11"
+  PLATFORM_CXXFLAGS="-std=c++17"
 fi
 
 # we currently depend on POSIX platform
@@ -794,24 +794,8 @@ if [ "$?" = 0 ]; then
   COMMON_FLAGS="$COMMON_FLAGS -DHAVE_UINT128_EXTENSION"
 fi
 
-# iOS doesn't support thread-local storage, but this check would erroneously
-# succeed because the cross-compiler flags are added by the Makefile, not this
-# script.
-if [ "$PLATFORM" != IOS ]; then
-  $CXX $COMMON_FLAGS -x c++ - -o test.o 2>/dev/null <<EOF
-  #if defined(_MSC_VER) && !defined(__thread)
-  #define __thread __declspec(thread)
-  #endif
-  int main() {
-    static __thread int tls;
-    (void)tls;
-  }
-EOF
-  if [ "$?" = 0 ]; then
-    COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_SUPPORT_THREAD_LOCAL"
-  fi
-fi
-
+# thread_local is part of C++11 and later (TODO: clean up this define)
+COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_SUPPORT_THREAD_LOCAL"
 
 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