Makefile: generate util/build_version.cc from .in file (#1384)

* util/build_verion.cc.in: add this file, so cmake and make can share the
  template file for generating util/build_version.cc.
* CMakeLists.txt: also, cmake v2.8.11 does not support file(GENERATE ...),
  so we are using configure_file() for creating build_version.cc.
* Makefile: use util/build_verion.cc.in for creating build_version.cc.

Signed-off-by: Kefu Chai <tchaikov@gmail.com>

CMakeLists.txt

@@ -79,12 +79,7 @@ endif()
 string(REGEX REPLACE "[^0-9a-f]+" "" GIT_SHA "${GIT_SHA}")
 
 set(BUILD_VERSION_CC ${CMAKE_BINARY_DIR}/build_version.cc)
-file(GENERATE OUTPUT ${BUILD_VERSION_CC} CONTENT
+configure_file(util/build_version.cc.in ${BUILD_VERSION_CC} @ONLY)
-  "#include \"build_version.h\"
-const char* rocksdb_build_git_sha = \"rocksdb_build_git_sha:${GIT_SHA}\";
-const char* rocksdb_build_git_datetime = \"rocksdb_build_git_datetime:${GIT_DATE_TIME}\";
-const char* rocksdb_build_compile_date = __DATE__;
-")
 add_library(build_version OBJECT ${BUILD_VERSION_CC})
 target_include_directories(build_version PRIVATE
   ${CMAKE_CURRENT_SOURCE_DIR}/util)

Makefile

@@ -231,14 +231,7 @@ ifdef FORCE_GIT_SHA
 else
 	git_sha := $(shell git rev-parse HEAD 2>/dev/null)
 endif
-gen_build_version =							\
+gen_build_version = sed -e s/@@GIT_SHA@@/$(git_sha)/ -e s/@@GIT_DATE_TIME@@/$(date)/ util/build_version.cc.in
-  printf '%s\n'								\
-    '\#include "build_version.h"'					\
-    'const char* rocksdb_build_git_sha =				\
-      "rocksdb_build_git_sha:$(git_sha)";'			\
-    'const char* rocksdb_build_git_date =				\
-      "rocksdb_build_git_date:$(date)";'				\
-    'const char* rocksdb_build_compile_date = __DATE__;'
 
 # Record the version of the source that we are compiling.
 # We keep a record of the git revision in this file.  It is then built

util/build_version.cc.in

@@ -0,0 +1,4 @@
+#include "build_version.h"
+const char* rocksdb_build_git_sha = "rocksdb_build_git_sha:@@GIT_SHA@@";
+const char* rocksdb_build_git_date = "rocksdb_build_git_date:@@GIT_DATE_TIME@@";
+const char* rocksdb_build_compile_date = __DATE__;