Github user jcrist commented on a diff in the pull request:
https://github.com/apache/orc/pull/192#discussion_r152660084
--- Diff: cmake_modules/ThirdpartyToolchain.cmake ---
@@ -10,19 +10,46 @@
# See the License for the specific language governing permissions and
# limitations under the License.
+set (LZ4_VERSION "1.7.5")
+set (SNAPPY_VERSION "1.1.4")
+set (ZLIB_VERSION "1.2.11")
+set (GTEST_VERSION "1.8.0")
+set (PROTOBUF_VERSION "2.6.0")
+
set (THIRDPARTY_DIR "${CMAKE_BINARY_DIR}/c++/libs/thirdparty")
string(TOUPPER ${CMAKE_BUILD_TYPE} UPPERCASE_BUILD_TYPE)
+if (DEFINED ENV{SNAPPY_HOME})
+ set (SNAPPY_HOME "$ENV{SNAPPY_HOME}")
+endif ()
+
+if (DEFINED ENV{ZLIB_HOME})
+ set (ZLIB_HOME "$ENV{ZLIB_HOME}")
+endif ()
+
+if (DEFINED ENV{LZ4_HOME})
+ set (LZ4_HOME "$ENV{LZ4_HOME}")
+endif ()
+
+if (DEFINED ENV{PROTOBUF_HOME})
+ set (PROTOBUF_HOME "$ENV{PROTOBUF_HOME}")
+endif ()
+
+if (DEFINED ENV{GTEST_HOME})
+ set (GTEST_HOME "$ENV{GTEST_HOME}")
+endif ()
+
# ----------------------------------------------------------------------
# Snappy
-set (SNAPPY_HOME "$ENV{SNAPPY_HOME}")
-find_package (Snappy)
-if (NOT SNAPPY_FOUND)
+if (NOT "${SNAPPY_HOME}" STREQUAL "")
+ find_package (Snappy REQUIRED)
+ set(SNAPPY_VENDORED FALSE)
+else ()
--- End diff --
As I wrote it, we error out if `SNAPPY_HOME` is set but not found (since
`REQUIRED` is set). I think this makes more sense - as a user if I specify
`SNAPPY_HOME` I'd rather get an error than silently download and build a new
version if it fails to find it.
---
