cross-platform compatibility improvements

Summary:
We've had a couple CockroachDB users fail to build RocksDB on exotic platforms, so I figured I'd try my hand at solving these issues upstream. The problems stem from a) `USE_SSE=1` being too aggressive about turning on SSE4.2, even on toolchains that don't support SSE4.2 and b) RocksDB attempting to detect support for thread-local storage based on OS, even though it can vary by compiler on the same OS.

See the individual commit messages for details. Regarding SSE support, this PR should change virtually nothing for non-CMake based builds. `make`, `PORTABLE=1 make`, `USE_SSE=1 make`, and `PORTABLE=1 USE_SSE=1 make` function exactly as before, except that SSE support will be automatically disabled when a simple SSE4.2-using test program fails to compile, as it does on OpenBSD. (OpenBSD's ports GCC supports SSE4.2, but its binutils do not, so `__SSE_4_2__` is defined but an SSE4.2-using program will fail to assemble.) A warning is emitted in this case. The CMake build is modified to support the same set of options, except that `USE_SSE` is spelled `FORCE_SSE42` because `USE_SSE` is rather useless now that we can automatically detect SSE support, and I figure changing options in the CMake build is less disruptive than changing the non-CMake build.

I've tested these changes on all the platforms I can get my hands on (macOS, Windows MSVC, Windows MinGW, and OpenBSD) and it all works splendidly. Let me know if there's anything you object to—I obviously don't mean to break any of your build pipelines in the process of fixing ours downstream.
Closes facebook#2199

Differential Revision: D5054042

Pulled By: yiwu-arbug

fbshipit-source-id: 938e1fc665c049c02ae15698e1409155b8e72171

CMakeLists.txt

@@ -106,31 +106,58 @@ if(NOT WIN32)
   string(STRIP "${ROCKSDB_VERSION_MAJOR}" ROCKSDB_VERSION_MAJOR)
 endif()
 
-if(WIN32)
-  option(WITH_AVX2 "build with AVX2" ON)
-  if(WITH_AVX2)
-    if(MSVC)
-      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /arch:AVX2")
-    else()
-      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mavx2")
-    endif()
+option(WITH_MD_LIBRARY "build with MD" ON)
+if(WIN32 AND MSVC)
+  if(WITH_MD_LIBRARY)
+    set(RUNTIME_LIBRARY "MD")
+  else()
+    set(RUNTIME_LIBRARY "MT")
   endif()
+endif()
 
-  option(WITH_MD_LIBRARY "build with MD" ON)
-  if(MSVC)
-    if(WITH_MD_LIBRARY)
-      set(RUNTIME_LIBRARY "MD")
-    else()
-      set(RUNTIME_LIBRARY "MT")
-    endif()
+option(PORTABLE "build a portable binary" OFF)
+option(FORCE_SSE42 "force building with SSE4.2, even when PORTABLE=ON" OFF)
+if(PORTABLE)
+  # MSVC does not need a separate compiler flag to enable SSE4.2; if nmmintrin.h
+  # is available, it is available by default.
+  if(FORCE_SSE42 AND NOT MSVC)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -msse4.2")
   endif()
 else()
-  option(WITH_SSE42 "build with SSE4.2" ON)
-  if(WITH_SSE42)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -msse4.2")
+  if(MSVC)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /arch:AVX2")
+  else()
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native")
   endif()
 endif()
 
+set(CMAKE_REQUIRED_FLAGS ${CMAKE_CXX_FLAGS})
+include(CheckCXXSourceCompiles)
+CHECK_CXX_SOURCE_COMPILES("
+#include <cstdint>
+#include <nmmintrin.h>
+int main() {
+  volatile uint32_t x = _mm_crc32_u32(0, 0);
+}
+" HAVE_SSE42)
+if(HAVE_SSE42)
+  add_definitions(-DHAVE_SSE42)
+elseif(FORCE_SSE42)
+  message(FATAL_ERROR "FORCE_SSE42=ON but unable to compile with SSE4.2 enabled")
+endif()
+
+CHECK_CXX_SOURCE_COMPILES("
+#if defined(_MSC_VER) && !defined(__thread)
+#define __thread __declspec(thread)
+#endif
+int main() {
+  static __thread int tls;
+}
+" HAVE_THREAD_LOCAL)
+if(HAVE_THREAD_LOCAL)
+  add_definitions(-DROCKSDB_SUPPORT_THREAD_LOCAL)
+endif()
+
 set(BUILD_VERSION_CC ${CMAKE_BINARY_DIR}/build_version.cc)
 configure_file(util/build_version.cc.in ${BUILD_VERSION_CC} @ONLY)
 add_library(build_version OBJECT ${BUILD_VERSION_CC})
@@ -520,7 +547,7 @@ if(WIN32)
   set(SYSTEM_LIBS ${SYSTEM_LIBS} Shlwapi.lib Rpcrt4.lib)
   set(LIBS ${ROCKSDB_STATIC_LIB} ${THIRDPARTY_LIBS} ${SYSTEM_LIBS})
 else()
-  set(SYSTEM_LIBS ${CMAKE_THREAD_LIBS_INIT} rt)
+  set(SYSTEM_LIBS ${CMAKE_THREAD_LIBS_INIT})
   set(LIBS ${ROCKSDB_SHARED_LIB} ${THIRDPARTY_LIBS} ${SYSTEM_LIBS})
 
   add_library(${ROCKSDB_SHARED_LIB} SHARED ${SOURCES})

INSTALL.md

@@ -21,9 +21,11 @@ depend on gflags. You will need to have gflags installed to run `make all`. This
 use binaries compiled by `make all` in production.
 
 * By default the binary we produce is optimized for the platform you're compiling on
-(-march=native or the equivalent). If you want to build a portable binary, add 'PORTABLE=1' before
-your make commands, like this: `PORTABLE=1 make static_lib`. If you want to build a binary that
-makes use of SSE4, add 'USE_SSE=1' before your make commands, like this: `USE_SSE=1 make static_lib`.
+(`-march=native` or the equivalent). SSE4.2 will thus be enabled automatically if your
+CPU supports it. To print a warning if your CPU does not support SSE4.2, build with
+`USE_SSE=1 make static_lib` or, if using CMake, `cmake -DFORCE_SSE42=ON`. If you want
+to build a portable binary, add `PORTABLE=1` before your make commands, like this:
+`PORTABLE=1 make static_lib`.
 
 ## Dependencies
 

TARGETS

@@ -11,6 +11,7 @@ rocksdb_compiler_flags = [
   "-DROCKSDB_MALLOC_USABLE_SIZE",
   "-DROCKSDB_RANGESYNC_PRESENT",
   "-DROCKSDB_SCHED_GETCPU_PRESENT",
+  "-DROCKSDB_SUPPORT_THREAD_LOCAL",
   "-DOS_LINUX",
   # Flags to enable libs we include
   "-DSNAPPY",

build_tools/build_detect_platform

@@ -442,14 +442,8 @@ if test "$USE_HDFS"; then
   JAVA_LDFLAGS="$JAVA_LDFLAGS $HDFS_LDFLAGS"
 fi
 
-if [ "$TARGET_OS" = FreeBSD -a "$TARGET_ARCHITECTURE" = i386 ]; then
-  # Intel SSE instructions breaks compilation on FreeBSD i386
-  unset USE_SSE
-fi
-
 if test "$USE_SSE"; then
-  # if Intel SSE instruction set is supported, set USE_SSE=1
-  COMMON_FLAGS="$COMMON_FLAGS -msse -msse4.2 "
+  COMMON_FLAGS="$COMMON_FLAGS -msse4.2"
 elif test -z "$PORTABLE"; then
   if test -n "`echo $TARGET_ARCHITECTURE | grep ^ppc64`"; then
     # Tune for this POWER processor, treating '+' models as base models
@@ -462,6 +456,36 @@ elif test -z "$PORTABLE"; then
   fi
 fi
 
+$CXX $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null <<EOF
+  #include <cstdint>
+  #include <nmmintrin.h>
+  int main() {
+    volatile uint32_t x = _mm_crc32_u32(0, 0);
+  }
+EOF
+if [ "$?" = 0 ]; then
+  COMMON_FLAGS="$COMMON_FLAGS -DHAVE_SSE42"
+elif test "$USE_SSE"; then
+  echo "warning: USE_SSE specified but compiler could not use SSE intrinsics, disabling"
+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 $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null <<EOF
+  #if defined(_MSC_VER) && !defined(__thread)
+  #define __thread __declspec(thread)
+  #endif
+  int main() {
+    static __thread int tls;
+  }
+EOF
+  if [ "$?" = 0 ]; then
+    COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_SUPPORT_THREAD_LOCAL"
+  fi
+fi
+
 PLATFORM_CCFLAGS="$PLATFORM_CCFLAGS $COMMON_FLAGS"
 PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS $COMMON_FLAGS"
 

include/rocksdb/iostats_context.h

@@ -7,6 +7,7 @@
 #include <stdint.h>
 #include <string>
 
+#include "port/port.h"
 #include "rocksdb/perf_level.h"
 
 // A thread local context for gathering io-stats efficiently and transparently.
@@ -46,12 +47,8 @@ struct IOStatsContext {
   uint64_t logger_nanos;
 };
 
-#ifndef IOS_CROSS_COMPILE
-# ifdef _MSC_VER
-extern __declspec(thread) IOStatsContext iostats_context;
-# else
+#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
 extern __thread IOStatsContext iostats_context;
-# endif
-#endif  // IOS_CROSS_COMPILE
+#endif
 
 }  // namespace rocksdb

include/rocksdb/perf_context.h

@@ -9,6 +9,7 @@
 #include <stdint.h>
 #include <string>
 
+#include "port/port.h"
 #include "rocksdb/perf_level.h"
 
 namespace rocksdb {
@@ -150,10 +151,8 @@ struct PerfContext {
   uint64_t env_new_logger_nanos;
 };
 
-#if defined(NPERF_CONTEXT) || defined(IOS_CROSS_COMPILE)
+#if defined(NPERF_CONTEXT) || !defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
 extern PerfContext perf_context;
-#elif defined(_MSC_VER)
-extern __declspec(thread) PerfContext perf_context;
 #else
   #if defined(OS_SOLARIS)
     PerfContext *getPerfContext();

include/rocksdb/thread_status.h

@@ -22,8 +22,7 @@
 
 #if !defined(ROCKSDB_LITE) && \
     !defined(NROCKSDB_THREAD_STATUS) && \
-    !defined(OS_MACOSX) && \
-    !defined(IOS_CROSS_COMPILE)
+    defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
 #define ROCKSDB_USING_THREAD_STATUS
 #endif
 

monitoring/iostats_context.cc

@@ -9,13 +9,9 @@
 
 namespace rocksdb {
 
-#ifndef IOS_CROSS_COMPILE
-# ifdef _MSC_VER
-__declspec(thread) IOStatsContext iostats_context;
-# else
+#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
 __thread IOStatsContext iostats_context;
-# endif
-#endif  // IOS_CROSS_COMPILE
+#endif
 
 void IOStatsContext::Reset() {
   thread_pool_id = Env::Priority::TOTAL;

monitoring/iostats_context_imp.h

@@ -9,7 +9,7 @@
 #include "monitoring/perf_step_timer.h"
 #include "rocksdb/iostats_context.h"
 
-#ifndef IOS_CROSS_COMPILE
+#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
 
 // increment a specific counter by the specified value
 #define IOSTATS_ADD(metric, value)     \
@@ -41,7 +41,7 @@
   PerfStepTimer iostats_step_timer_ ## metric(&(iostats_context.metric));  \
   iostats_step_timer_ ## metric.Start();
 
-#else  // IOS_CROSS_COMPILE
+#else  // ROCKSDB_SUPPORT_THREAD_LOCAL
 
 #define IOSTATS_ADD(metric, value)
 #define IOSTATS_ADD_IF_POSITIVE(metric, value)
@@ -53,4 +53,4 @@
 
 #define IOSTATS_TIMER_GUARD(metric)
 
-#endif  // IOS_CROSS_COMPILE
+#endif  // ROCKSDB_SUPPORT_THREAD_LOCAL

monitoring/perf_context.cc

@@ -11,10 +11,8 @@
 
 namespace rocksdb {
 
-#if defined(NPERF_CONTEXT) || defined(IOS_CROSS_COMPILE)
+#if defined(NPERF_CONTEXT) || !defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
   PerfContext perf_context;
-#elif defined(_MSC_VER)
-  __declspec(thread) PerfContext perf_context;
 #else
   #if defined(OS_SOLARIS)
     __thread PerfContext perf_context_;
@@ -24,7 +22,7 @@ namespace rocksdb {
 #endif
 
 void PerfContext::Reset() {
-#if !defined(NPERF_CONTEXT) && !defined(IOS_CROSS_COMPILE)
+#if !defined(NPERF_CONTEXT) && defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
   user_key_comparison_count = 0;
   block_cache_hit_count = 0;
   block_read_count = 0;
@@ -98,7 +96,7 @@ void PerfContext::Reset() {
   }
 
 std::string PerfContext::ToString(bool exclude_zero_counters) const {
-#if defined(NPERF_CONTEXT) || defined(IOS_CROSS_COMPILE)
+#if defined(NPERF_CONTEXT) || !defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
   return "";
 #else
   std::ostringstream ss;

monitoring/perf_context_imp.h

@@ -12,7 +12,7 @@
 
 namespace rocksdb {
 
-#if defined(NPERF_CONTEXT) || defined(IOS_CROSS_COMPILE)
+#if defined(NPERF_CONTEXT) || !defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
 
 #define PERF_TIMER_GUARD(metric)
 #define PERF_CONDITIONAL_TIMER_FOR_MUTEX_GUARD(metric, condition)

monitoring/perf_level.cc

@@ -7,16 +7,14 @@
 //
 
 #include <assert.h>
-#include <sstream>
 #include "monitoring/perf_level_imp.h"
-#include "port/port.h"
 
 namespace rocksdb {
 
-#if defined(IOS_CROSS_COMPILE)
-PerfLevel perf_level = kEnableCount;
-#else
+#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
 __thread PerfLevel perf_level = kEnableCount;
+#else
+PerfLevel perf_level = kEnableCount;
 #endif
 
 void SetPerfLevel(PerfLevel level) {

monitoring/perf_level_imp.h

@@ -11,10 +11,10 @@
 
 namespace rocksdb {
 
-#if defined(IOS_CROSS_COMPILE)
-extern PerfLevel perf_level;
-#else
+#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
 extern __thread PerfLevel perf_level;
+#else
+extern PerfLevel perf_level;
 #endif
 
 }  // namespace rocksdb