Merge pull request #7126 from tchaikov/wip-detect-bzip2-lz4

cmake: detect bzip2 and lz4

CMakeLists.txt

@@ -243,9 +243,8 @@ endif(WITH_REENTRANT_STRSIGNAL)
 
 set(HAVE_LIBROCKSDB 1)
 
-# -lbz2 and -lz link into kv
+# -lz link into kv
 find_package(ZLIB REQUIRED)
-find_package(BZip2 REQUIRED)
 
 #option for LTTng
 option(WITH_LTTNG "LTTng tracing is enabled" ON)

cmake/modules/FindLZ4.cmake

@@ -0,0 +1,15 @@
+# Try to find liblz4
+#
+# Once done, this will define
+#
+# LZ4_FOUND
+# LZ4_INCLUDE_DIR
+# LZ4_LIBRARY
+
+find_path(LZ4_INCLUDE_DIR NAMES lz4.h)
+find_library(LZ4_LIBRARY NAMES lz4)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(LZ4 DEFAULT_MSG LZ4_LIBRARY LZ4_INCLUDE_DIR)
+
+mark_as_advanced(LZ4_INCLUDE_DIR LZ4_LIBRARY)

src/kv/CMakeLists.txt

@@ -6,4 +6,14 @@ add_library(kv_objs OBJECT ${kv_srcs})
 add_library(kv STATIC $<TARGET_OBJECTS:kv_objs>)
 target_include_directories(kv_objs PUBLIC ${ROCKSDB_INCLUDE_DIR})
 target_include_directories(kv PUBLIC ${ROCKSDB_INCLUDE_DIR})
-target_link_libraries(kv bz2 z leveldb snappy rocksdb)
+target_link_libraries(kv z leveldb snappy rocksdb)
+
+# rocksdb detects bzlib and lz4 in its Makefile, which forces us to do the same.
+find_package(BZip2 QUIET)
+if (BZIP2_FOUND)
+  target_link_libraries(kv ${BZIP2_LIBRARIES})
+endif (BZIP2_FOUND)
+find_package(LZ4 QUIET)
+if (LZ4_FOUND)
+  target_link_libraries(kv ${LZ4_LIBRARY})
+endif (LZ4_FOUND)