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

1 files changed, 7 insertions, 1 deletions

diff --git a/java/src/main/java/org/rocksdb/util/Environment.java b/java/src/main/java/org/rocksdb/util/Environment.java
index 36a4b4a20..7e1b50cff 100644
--- a/java/src/main/java/org/rocksdb/util/Environment.java
+++ b/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");