Check for the zstd version

externals/find-modules/Findzstd.cmake

@@ -11,12 +11,26 @@ find_library(zstd_LIBRARY
   PATHS ${PC_zstd_LIBRARY_DIRS}
 )
 
+if(zstd_INCLUDE_DIR)
+  file(STRINGS "${zstd_INCLUDE_DIR}/zstd.h" _zstd_version_lines
+    REGEX "#define[ \t]+ZSTD_VERSION_(MAJOR|MINOR|RELEASE)")
+  string(REGEX REPLACE ".*ZSTD_VERSION_MAJOR *\([0-9]*\).*" "\\1" _zstd_version_major "${_zstd_version_lines}")
+  string(REGEX REPLACE ".*ZSTD_VERSION_MINOR *\([0-9]*\).*" "\\1" _zstd_version_minor "${_zstd_version_lines}")
+  string(REGEX REPLACE ".*ZSTD_VERSION_RELEASE *\([0-9]*\).*" "\\1" _zstd_version_release "${_zstd_version_lines}")
+  set(zstd_VERSION "${_zstd_version_major}.${_zstd_version_minor}.${_zstd_version_release}")
+  unset(_zstd_version_major)
+  unset(_zstd_version_minor)
+  unset(_zstd_version_release)
+  unset(_zstd_version_lines)
+endif()
+
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(zstd
   FOUND_VAR zstd_FOUND
   REQUIRED_VARS
     zstd_LIBRARY
     zstd_INCLUDE_DIR
+    zstd_VERSION
   VERSION_VAR zstd_VERSION
 )