From b94de32423312e4cbb9e167e74ac3e3de73c00a1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=93=D0=B5=D0=BE=D1=80=D0=B3=D0=B8=D0=B9=20=D0=9A=D0=BE?=
 =?UTF-8?q?=D0=BD=D0=B4=D1=80=D0=B0=D1=82=D1=8C=D0=B5=D0=B2?=
 <orivej@yandex-team.ru>
Date: Sun, 24 Feb 2019 21:20:46 +0000
Subject: [PATCH] Support xxHash with external lz4

xxhash.h does not exist in external lz4 because it is an implementation detail
and its symbols are namespaced with XXH_NAMESPACE macro.  When lz4 is external,
xxHash has to be external too, and the dependents have to link to it.

This find_xxhash.cmake is based on find_lz4.cmake.
---
 cmake/find_xxhash.cmake           | 27 +++++++++++++++++----------
 dbms/src/Functions/CMakeLists.txt |  8 ++++++--
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/cmake/find_xxhash.cmake b/cmake/find_xxhash.cmake
index 41e323ffe67..8af871e8fd5 100644
--- a/cmake/find_xxhash.cmake
+++ b/cmake/find_xxhash.cmake
@@ -1,15 +1,22 @@
-# Freebsd: TODO: use system devel/xxhash. now error: undefined reference to `XXH32'
-if (LZ4_INCLUDE_DIR)
-    if (NOT EXISTS "${LZ4_INCLUDE_DIR}/xxhash.h")
-        message (WARNING "LZ4 library does not have XXHash. Support for XXHash will be disabled.")
-        set (USE_XXHASH 0)
-    else ()
-        set (USE_XXHASH 1)
-    endif ()
+option (USE_INTERNAL_XXHASH_LIBRARY "Set to FALSE to use system xxHash library instead of bundled" ${NOT_UNBUNDLED})
+
+if (USE_INTERNAL_XXHASH_LIBRARY AND NOT USE_INTERNAL_LZ4_LIBRARY)
+    message (WARNING "can not use internal xxhash without internal lz4")
+    set (USE_INTERNAL_XXHASH_LIBRARY 0)
 endif ()
 
-if (OS_FREEBSD AND NOT USE_INTERNAL_LZ4_LIBRARY)
+if (USE_INTERNAL_XXHASH_LIBRARY)
+    set (XXHASH_LIBRARY lz4)
+    set (XXHASH_INCLUDE_DIR ${ClickHouse_SOURCE_DIR}/contrib/lz4/lib)
+else ()
+    find_library (XXHASH_LIBRARY xxhash)
+    find_path (XXHASH_INCLUDE_DIR NAMES xxhash.h PATHS ${XXHASH_INCLUDE_PATHS})
+endif ()
+
+if (XXHASH_LIBRARY AND XXHASH_INCLUDE_DIR)
+    set (USE_XXHASH 1)
+else ()
     set (USE_XXHASH 0)
 endif ()
 
-message (STATUS "Using xxhash=${USE_XXHASH}")
+message (STATUS "Using xxhash=${USE_XXHASH}: ${XXHASH_INCLUDE_DIR} : ${XXHASH_LIBRARY}")
diff --git a/dbms/src/Functions/CMakeLists.txt b/dbms/src/Functions/CMakeLists.txt
index 89807a428e3..e767c17de92 100644
--- a/dbms/src/Functions/CMakeLists.txt
+++ b/dbms/src/Functions/CMakeLists.txt
@@ -20,8 +20,7 @@ target_link_libraries(clickhouse_functions
         ${METROHASH_LIBRARIES}
         murmurhash
         ${BASE64_LIBRARY}
-        ${OPENSSL_CRYPTO_LIBRARY}
-        ${LZ4_LIBRARY})
+        ${OPENSSL_CRYPTO_LIBRARY})
 
 target_include_directories (clickhouse_functions SYSTEM BEFORE PUBLIC ${DIVIDE_INCLUDE_DIR} ${METROHASH_INCLUDE_DIR})
 
@@ -56,3 +55,8 @@ endif ()
 if(USE_BASE64)
     target_include_directories(clickhouse_functions SYSTEM PRIVATE ${BASE64_INCLUDE_DIR})
 endif()
+
+if (USE_XXHASH)
+    target_link_libraries(clickhouse_functions PRIVATE ${XXHASH_LIBRARY})
+    target_include_directories(clickhouse_functions SYSTEM PRIVATE ${XXHASH_INCLUDE_DIR})
+endif()