Don't keep managing two rocksdb version

Summary:
Before this diff, there are two places with rocksdb versions. After the diff:
1. we only have one source of truth for rocksdb version
2. we have a script that we can use to get the version that we can use in other compilations (java, go, etc).

Test Plan: make

Reviewers: yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D24333

Makefile

@@ -164,9 +164,6 @@ endif
 LIBRARY = ${LIBNAME}.a
 MEMENVLIBRARY = libmemenv.a
 
-ROCKSDB_MAJOR = 3
-ROCKSDB_MINOR = 4
-
 default: all
 
 #-----------------------------------------------
@@ -178,22 +175,26 @@ ifneq ($(PLATFORM_SHARED_VERSIONED),true)
 SHARED1 = ${LIBNAME}.$(PLATFORM_SHARED_EXT)
 SHARED2 = $(SHARED1)
 SHARED3 = $(SHARED1)
+SHARED4 = $(SHARED1)
 SHARED = $(SHARED1)
 else
-# Update db.h if you change these.
 SHARED_MAJOR = $(ROCKSDB_MAJOR)
 SHARED_MINOR = $(ROCKSDB_MINOR)
+SHARED_PATCH = $(ROCKSDB_PATCH)
 SHARED1 = ${LIBNAME}.$(PLATFORM_SHARED_EXT)
 SHARED2 = $(SHARED1).$(SHARED_MAJOR)
 SHARED3 = $(SHARED1).$(SHARED_MAJOR).$(SHARED_MINOR)
-SHARED = $(SHARED1) $(SHARED2) $(SHARED3)
-$(SHARED1): $(SHARED3)
-	ln -fs $(SHARED3) $(SHARED1)
-$(SHARED2): $(SHARED3)
-	ln -fs $(SHARED3) $(SHARED2)
+SHARED4 = $(SHARED1).$(SHARED_MAJOR).$(SHARED_MINOR).$(SHARED_PATCH)
+SHARED = $(SHARED1) $(SHARED2) $(SHARED3) $(SHARED4)
+$(SHARED1): $(SHARED4)
+	ln -fs $(SHARED4) $(SHARED1)
+$(SHARED2): $(SHARED4)
+	ln -fs $(SHARED4) $(SHARED2)
+$(SHARED3): $(SHARED4)
+	ln -fs $(SHARED4) $(SHARED3)
 endif
 
-$(SHARED3):
+$(SHARED4):
 	$(CXX) $(PLATFORM_SHARED_LDFLAGS)$(SHARED2) $(CXXFLAGS) $(PLATFORM_SHARED_CFLAGS) $(SOURCES) $(LDFLAGS) -o $@
 
 endif  # PLATFORM_SHARED_EXT

build_tools/build_detect_platform

@@ -326,6 +326,10 @@ PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS $COMMON_FLAGS"
 
 VALGRIND_VER="$VALGRIND_VER"
 
+ROCKSDB_MAJOR=`build_tools/version.sh major`
+ROCKSDB_MINOR=`build_tools/version.sh minor`
+ROCKSDB_PATCH=`build_tools/version.sh patch`
+
 echo "CC=$CC" >> "$OUTPUT"
 echo "CXX=$CXX" >> "$OUTPUT"
 echo "PLATFORM=$PLATFORM" >> "$OUTPUT"
@@ -341,3 +345,6 @@ echo "PLATFORM_SHARED_VERSIONED=$PLATFORM_SHARED_VERSIONED" >> "$OUTPUT"
 echo "EXEC_LDFLAGS=$EXEC_LDFLAGS" >> "$OUTPUT"
 echo "JEMALLOC_INCLUDE=$JEMALLOC_INCLUDE" >> "$OUTPUT"
 echo "JEMALLOC_LIB=$JEMALLOC_LIB" >> "$OUTPUT"
+echo "ROCKSDB_MAJOR=$ROCKSDB_MAJOR" >> "$OUTPUT"
+echo "ROCKSDB_MINOR=$ROCKSDB_MINOR" >> "$OUTPUT"
+echo "ROCKSDB_PATCH=$ROCKSDB_PATCH" >> "$OUTPUT"

build_tools/version.sh

@@ -0,0 +1,12 @@
+if [ $# == 0 ]; then
+  echo "Usage: $0 major|minor|patch"
+fi
+if [[ $1 == "major" ]]; then
+  cat include/rocksdb/version.h  | grep MAJOR | head -n1 | awk '{print $3}'
+fi
+if [[ $1 = "minor" ]]; then
+  cat include/rocksdb/version.h  | grep MINOR | head -n1 | awk '{print $3}'
+fi
+if [[ $1 = "patch" ]]; then
+  cat include/rocksdb/version.h  | grep PATCH | head -n1 | awk '{print $3}'
+fi

include/rocksdb/version.h

@@ -4,9 +4,8 @@
 // of patent rights can be found in the PATENTS file in the same directory.
 #pragma once
 
-// Also update Makefile if you change these
 #define ROCKSDB_MAJOR 3
-#define ROCKSDB_MINOR 5
+#define ROCKSDB_MINOR 6
 #define ROCKSDB_PATCH 0
 
 // Do not use these. We made the mistake of declaring macros starting with