Record the version of the source repository that was used to build th…

…e leveldb library.

Summary: Record the version of the source that we are compiling. We keep a record of the git revision in util/version.cc. This source file is then built as a regular source file as part of the compilation process. One can run "strings executable_filename | grep _build_" to find the version of the source that we used to build the executable file.

Test Plan: none

Differential Revision: https://reviews.facebook.net/D4785

Makefile

@@ -87,7 +87,6 @@ $(SHARED1): $(SHARED3)
 	ln -fs $(SHARED3) $(SHARED1)
 endif
 
-
 all: $(VERSIONFILE) $(SHARED) $(LIBRARY) $(THRIFTSERVER) $(TOOLS)
 
 check: all $(PROGRAMS) $(TESTS) $(TOOLS)
@@ -200,6 +199,9 @@ $(VERSIONFILE):	build_detect_version
 filelock_test: util/filelock_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) util/filelock_test.o $(LIBOBJECTS) $(TESTHARNESS) -o $@ $(LDFLAGS)
 
+# recreate the version file with the latest git revision
+$(VERSIONFILE):	build_detect_version
+	$(shell ./build_detect_platform build_config.mk)
 
 ifeq ($(PLATFORM), IOS)
 # For iOS, create universal object files to be used on both the simulator and

build_detect_version

@@ -22,4 +22,3 @@ fi
 date | awk 'BEGIN {} {print "const char * leveldb_build_git_datetime = \"leveldb_build_git_datetime:"$0"\";"} END {} ' >> ${VFILE}
 echo "const char * leveldb_build_compile_date = __DATE__;" >> ${VFILE}
 echo "const char * leveldb_build_compile_time = __TIME__;" >> ${VFILE}
-