[kudu] branch master updated: KUDU-3334 hide protobuf symbols in libkudu_client

[al...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

alexey pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/kudu.git


The following commit(s) were added to refs/heads/master by this push:
     new 5d39a74  KUDU-3334 hide protobuf symbols in libkudu_client
5d39a74 is described below

commit 5d39a74a19ecf03071105ac0065dc1124cfd4ea6
Author: Alexey Serbin <al...@apache.org>
AuthorDate: Fri Nov 5 00:02:57 2021 -0700

    KUDU-3334 hide protobuf symbols in libkudu_client
    
    As it turns out, there are conflicts during static initialization of
    symbols related to protobuf extensions in an application using
    libkudu_client and also linking in libprotobuf on its own.  That
    seems to be attributed to the creation of two independent descriptor
    pools in such cases [1].  At least, such issues became apparent when
    both the application and libkudu_client started using libprotobuf
    3.14.0.
    
    One example of an application described above is impalad.  It links in
    libkudu_client and libprotobuf: the former is used to talk to Kudu
    servers and the latter is necessary to communicate with other Impala's
    backend components via KRPC.
    
    This patch adds the --exclude-libs flag for the GNU linker [2] to
    completely hide all the symbols inherited by libkudu_client from
    libprotobuf which is statically linked into the Kudu C++ library
    in case of RELEASE builds.
    
    As for the rest of libraries statically linked into libkudu_client,
    it seems no problems encountered so far if those symbols are just made
    local using the version script mechanism, so no other libraries are put
    under --exclude-libs linker's flag except for libprotobuf.
    
    [1] https://stackoverflow.com/a/29975019
    [2] https://www.man7.org/linux/man-pages/man1/ld.1.html
    
    Change-Id: I584e1f726f8a4f368579c2c323a230fe98e29dee
    Reviewed-on: http://gerrit.cloudera.org:8080/18000
    Tested-by: Kudu Jenkins
    Reviewed-by: Attila Bukor <ab...@apache.org>
---
 src/kudu/client/CMakeLists.txt | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/kudu/client/CMakeLists.txt b/src/kudu/client/CMakeLists.txt
index bf23d6c..fcf5c2c 100644
--- a/src/kudu/client/CMakeLists.txt
+++ b/src/kudu/client/CMakeLists.txt
@@ -139,9 +139,11 @@ set(CLIENT_VERSION_PATCH 0)
 
 if(NOT APPLE)
   # Localize thirdparty symbols using a linker version script. This hides them
-  # from the client application. The OS X linker does not support the
-  # version-script option.
+  # from the client application. Also, completely remove libprotobuf symbols
+  # (see KUDU-3334 for details). The --version-script and --exclude-libs
+  # GNU ld linker's options are not supported by the OS X linker.
   set(LINK_FLAGS "-Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/symbols.map")
+  set(LINK_FLAGS "${LINK_FLAGS} -Wl,--exclude-libs=libprotobuf")
 endif()
 
 set_target_properties(kudu_client_exported