+- if test -z "${LZ4_CFLAGS}" -a -z "${LZ4_LIBS}"; then
+- # if the user did not explicitly specify flags, try to autodetect
+- PKG_CHECK_MODULES([LZ4],
+- [liblz4 >= 1.7.1],
+- [have_lz4="yes"],
+- [] # If this fails, we will do another test next
+- )
+- fi
+
+ saved_CFLAGS="${CFLAGS}"
+ saved_LIBS="${LIBS}"
+ CFLAGS="${CFLAGS} ${LZ4_CFLAGS}"
+ LIBS="${LIBS} ${LZ4_LIBS}"
+
+- # If pkgconfig check failed or LZ4_CFLAGS/LZ4_LIBS env vars
+- # are used, check the version directly in the LZ4 include file
+- if test "${have_lz4}" != "yes"; then
+- AC_CHECK_HEADERS([lz4.h],
+- [have_lz4h="yes"],
+- [])
+-
+- if test "${have_lz4h}" = "yes" ; then
+- AC_MSG_CHECKING([additionally if system LZ4 version >= 1.7.1])
+- AC_COMPILE_IFELSE(
+- [AC_LANG_PROGRAM([[
+-#include <lz4.h>
+- ]],
+- [[
+-/* Version encoding: MMNNPP (Major miNor Patch) - see lz4.h for details */
+-#if LZ4_VERSION_NUMBER < 10701L
+-#error LZ4 is too old
+-#endif
+- ]]
+- )],
+- [
+- AC_MSG_RESULT([ok])
+- have_lz4="yes"
+- ],
+- [AC_MSG_RESULT([system LZ4 library is too old])]
+- )
+- fi
+- fi
+-