add cmake lz4 support

add some instructions for build/cmake/README.md

build/cmake/programs/CMakeLists.txt

@@ -83,7 +83,9 @@ endif ()
 
 option(ZSTD_ZLIB_SUPPORT "ZLIB SUPPORT" OFF)
 option(ZSTD_LZMA_SUPPORT "LZMA SUPPORT" OFF)
+option(ZSTD_LZ4_SUPPORT "LZ4 SUPPORT" OFF)
 
+# Add gzip support
 if (ZSTD_ZLIB_SUPPORT)
     find_package(ZLIB REQUIRED)
 
@@ -96,6 +98,7 @@ if (ZSTD_ZLIB_SUPPORT)
     endif ()
 endif ()
 
+# Add lzma support
 if (ZSTD_LZMA_SUPPORT)
     find_package(LibLZMA REQUIRED)
 
@@ -107,3 +110,16 @@ if (ZSTD_LZMA_SUPPORT)
         message(SEND_ERROR "lzma library is missing")
     endif ()
 endif ()
+
+# Add lz4 support
+if (ZSTD_LZ4_SUPPORT)
+    find_package(LibLZ4 REQUIRED)
+
+    if (LIBLZ4_FOUND)
+        include_directories(${LIBLZ4_INCLUDE_DIRS})
+        target_link_libraries(zstd ${LIBLZ4_LIBRARIES})
+        set_property(TARGET zstd APPEND PROPERTY COMPILE_DEFINITIONS "ZSTD_LZ4COMPRESS;ZSTD_LZ4DECOMPRESS")
+    else ()
+        message(SEND_ERROR "lz4 library is missing")
+    endif ()
+endif ()