Enable compilation on OpenBSD

Summary:
I modified the Makefile so that we can compile rocksdb on OpenBSD.
The instructions for building have been added to INSTALL.md.
The whole compilation process works fine like this on OpenBSD-current
Closes https://github.com/facebook/rocksdb/pull/3617

Differential Revision: D7323754

Pulled By: siying

fbshipit-source-id: 990037d1cc69138d22f85bd77ef4dc8c1ba9edea

INSTALL.md

@@ -141,6 +141,27 @@ to build a portable binary, add `PORTABLE=1` before your make commands, like thi
         export JAVA_HOME=/usr/local/openjdk7
         gmake rocksdbjava
 
+* **OpenBSD** (6.3/-current):
+
+    * As RocksDB is not available in the ports yet you have to build it on your own:
+
+    * Install the dependencies for RocksDB:
+
+        pkg_add gmake gflags snappy bzip2 lz4 zstd git jdk bash findutils gnuwatch 
+
+    * Build RocksDB from source:
+
+        cd ~
+        git clone https://github.com/facebook/rocksdb.git
+        cd rocksdb
+        gmake static_lib
+
+    * Build RocksJava from source (optional):
+
+        cd rocksdb
+        export JAVA_HOME=/usr/local/jdk-1.8.0
+        export PATH=$PATH:/usr/local/jdk-1.8.0/bin
+        gmake rocksdbjava
 
 * **iOS**:
   * Run: `TARGET_OS=IOS make static_lib`. When building the project which uses rocksdb iOS library, make sure to define two important pre-processing macros: `ROCKSDB_LITE` and `IOS_CROSS_COMPILE`.

Makefile

@@ -278,6 +278,10 @@ default: all
 WARNING_FLAGS = -W -Wextra -Wall -Wsign-compare -Wshadow \
   -Wno-unused-parameter
 
+ifeq ($(PLATFORM), OS_OPENBSD)
+	WARNING_FLAGS += -Wno-unused-lambda-capture
+endif
+
 ifndef DISABLE_WARNING_AS_ERROR
 	WARNING_FLAGS += -Werror
 endif
@@ -674,7 +678,7 @@ coverage:
 	COVERAGEFLAGS="-fprofile-arcs -ftest-coverage" LDFLAGS+="-lgcov" $(MAKE) J=1 all check
 	cd coverage && ./coverage_test.sh
         # Delete intermediate files
-	find . -type f -regex ".*\.\(\(gcda\)\|\(gcno\)\)" -exec rm {} \;
+	$(FIND) . -type f -regex ".*\.\(\(gcda\)\|\(gcno\)\)" -exec rm {} \;
 
 ifneq (,$(filter check parallel_check,$(MAKECMDGOALS)),)
 # Use /dev/shm if it has the sticky bit set (otherwise, /tmp),
@@ -821,7 +825,7 @@ CLEAN_FILES += t LOG $(TMPD)
 # regardless of their duration. As with any use of "watch", hit ^C to
 # interrupt.
 watch-log:
-	watch --interval=0 'sort -k7,7nr -k4,4gr LOG|$(quoted_perl_command)'
+	$(WATCH) --interval=0 'sort -k7,7nr -k4,4gr LOG|$(quoted_perl_command)'
 
 # If J != 1 and GNU parallel is installed, run the tests in parallel,
 # via the check_0 rule above.  Otherwise, run them sequentially.
@@ -986,14 +990,14 @@ rocksdb.h rocksdb.cc: build_tools/amalgamate.py Makefile $(LIB_SOURCES) unity.cc
 clean:
 	rm -f $(BENCHMARKS) $(TOOLS) $(TESTS) $(LIBRARY) $(SHARED)
 	rm -rf $(CLEAN_FILES) ios-x86 ios-arm scan_build_report
-	find . -name "*.[oda]" -exec rm -f {} \;
-	find . -type f -regex ".*\.\(\(gcda\)\|\(gcno\)\)" -exec rm {} \;
+	$(FIND) . -name "*.[oda]" -exec rm -f {} \;
+	$(FIND) . -type f -regex ".*\.\(\(gcda\)\|\(gcno\)\)" -exec rm {} \;
 	rm -rf bzip2* snappy* zlib* lz4* zstd*
 	cd java; $(MAKE) clean
 
 tags:
 	ctags -R .
-	cscope -b `find . -name '*.cc'` `find . -name '*.h'` `find . -name '*.c'`
+	cscope -b `$(FIND) . -name '*.cc'` `$(FIND) . -name '*.h'` `$(FIND) . -name '*.c'`
 	ctags -e -R -o etags *
 
 format:
@@ -1510,10 +1514,10 @@ uninstall:
 
 install-headers:
 	install -d $(INSTALL_PATH)/lib
-	for header_dir in `find "include/rocksdb" -type d`; do \
+	for header_dir in `$(FIND) "include/rocksdb" -type d`; do \
 		install -d $(INSTALL_PATH)/$$header_dir; \
 	done
-	for header in `find "include/rocksdb" -type f -name *.h`; do \
+	for header in `$(FIND) "include/rocksdb" -type f -name *.h`; do \
 		install -C -m 644 $$header $(INSTALL_PATH)/$$header; \
 	done
 
@@ -1540,6 +1544,12 @@ install: install-static
 JAVA_INCLUDE = -I$(JAVA_HOME)/include/ -I$(JAVA_HOME)/include/linux
 ifeq ($(PLATFORM), OS_SOLARIS)
 	ARCH := $(shell isainfo -b)
+else ifeq ($(PLATFORM), OS_OPENBSD)
+	ifneq (,$(filter $(MACHINE), amd64 arm64 sparc64))
+		ARCH := 64
+	else
+		ARCH := 32
+	endif
 else
 	ARCH := $(shell getconf LONG_BIT)
 endif
@@ -1599,6 +1609,11 @@ ifeq ($(PLATFORM), OS_AIX)
 	EXTRACT_SOURCES = gunzip < TAR_GZ | tar xvf -
 	SNAPPY_MAKE_TARGET = libsnappy.la
 endif
+ifeq ($(PLATFORM), OS_OPENBSD)
+        JAVA_INCLUDE = -I$(JAVA_HOME)/include -I$(JAVA_HOME)/include/openbsd
+	ROCKSDBJNILIB = librocksdbjni-openbsd$(ARCH).so
+        ROCKSDB_JAR = rocksdbjni-$(ROCKSDB_MAJOR).$(ROCKSDB_MINOR).$(ROCKSDB_PATCH)-openbsd$(ARCH).jar
+endif
 
 libz.a:
 	-rm -rf zlib-$(ZLIB_VER)

build_tools/build_detect_platform

@@ -16,6 +16,8 @@
 #   PLATFORM_CXXFLAGS           C++ compiler flags.  Will contain:
 #   PLATFORM_SHARED_VERSIONED   Set to 'true' if platform supports versioned
 #                               shared libraries, empty otherwise.
+#   FIND			Command for the find utility
+#   WATCH			Command for the watch utility
 #
 # The PLATFORM_CCFLAGS and PLATFORM_CXXFLAGS might include the following:
 #
@@ -88,6 +90,14 @@ if test -z "$CLANG_ANALYZER"; then
     CLANG_ANALYZER=$(which clang++ 2> /dev/null)
 fi
 
+if test -z "$FIND"; then
+    FIND=find
+fi
+
+if test -z "$WATCH"; then
+    WATCH=watch
+fi
+
 COMMON_FLAGS="$COMMON_FLAGS ${CFLAGS}"
 CROSS_COMPILE=
 PLATFORM_CCFLAGS=
@@ -154,9 +164,12 @@ case "$TARGET_OS" in
         ;;
     OpenBSD)
         PLATFORM=OS_OPENBSD
+	CXX=clang++
         COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp -D_REENTRANT -DOS_OPENBSD"
         PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -pthread"
         # PORT_FILES=port/openbsd/openbsd_specific.cc
+	FIND=gfind
+	WATCH=gnuwatch
         ;;
     DragonFly)
         PLATFORM=OS_DRAGONFLYBSD
@@ -575,6 +588,8 @@ echo "ROCKSDB_PATCH=$ROCKSDB_PATCH" >> "$OUTPUT"
 echo "CLANG_SCAN_BUILD=$CLANG_SCAN_BUILD" >> "$OUTPUT"
 echo "CLANG_ANALYZER=$CLANG_ANALYZER" >> "$OUTPUT"
 echo "PROFILING_FLAGS=$PROFILING_FLAGS" >> "$OUTPUT"
+echo "FIND=$FIND" >> "$OUTPUT"
+echo "WATCH=$WATCH" >> "$OUTPUT"
 # This will enable some related identifiers for the preprocessor
 if test -n "$JEMALLOC"; then
   echo "JEMALLOC=1" >> "$OUTPUT"

java/src/main/java/org/rocksdb/util/Environment.java

@@ -33,6 +33,10 @@ public class Environment {
     return OS.contains("sunos");
   }
 
+  public static boolean isOpenBSD() {
+    return (OS.contains("openbsd"));
+  }
+
   public static boolean is64Bit() {
     if (ARCH.indexOf("sparcv9") >= 0) {
       return true;
@@ -67,6 +71,8 @@ public class Environment {
       return String.format("%sjni-solaris%s", name, arch);
     } else if (isWindows() && is64Bit()) {
       return String.format("%sjni-win64", name);
+    } else if (isOpenBSD()) {
+      return String.format("%sjni-openbsd%s", name, is64Bit() ? "64" : "32");
     }
 
     throw new UnsupportedOperationException(String.format("Cannot determine JNI library name for ARCH='%s' OS='%s' name='%s'", ARCH, OS, name));
@@ -77,7 +83,7 @@ public class Environment {
   }
 
   private static String appendLibOsSuffix(final String libraryFileName, final boolean shared) {
-    if (isUnix() || isAix() || isSolaris() || isFreeBSD()) {
+    if (isUnix() || isAix() || isSolaris() || isFreeBSD() || isOpenBSD()) {
       return libraryFileName + ".so";
     } else if (isMac()) {
       return libraryFileName + (shared ? ".dylib" : ".jnilib");