Merge pull request #28460 from tchaikov/wip-cmake-detect-libnl

cmake: rewrite Findgenl to support components argument

Reviewed-by: Jason Dillaman <dillaman@redhat.com>

CMakeLists.txt

@@ -218,22 +218,13 @@ if(LINUX)
   set(HAVE_UDEV ${UDEV_FOUND})
   find_package(blkid REQUIRED)
   set(HAVE_BLKID ${BLKID_FOUND})
-  if(WITH_RBD)
-    find_package(genl REQUIRED)
-    set(HAVE_GENL $GENL_FOUND)
-  endif()
 elseif(FREEBSD)
   set(HAVE_UDEV OFF)
   set(HAVE_LIBAIO OFF)
   set(HAVE_BLKID OFF)
-  set(HAVE_GENL OFF)
 else()
   set(HAVE_UDEV OFF)
-  message(STATUS "Not using udev")
   set(HAVE_BLKID OFF)
-  message(STATUS "Not using BLKID")
-  set(HAVE_GENL OFF)
-  message(STATUS "Not using GENL")
 endif(LINUX)
 
 option(WITH_OPENLDAP "OPENLDAP is here" ON)

cmake/modules/Findgenl.cmake

@@ -1,23 +0,0 @@
-# - Find libnl-genl3
-# Find the genl library and includes
-#
-# GENL_INCLUDE_DIR - where to find netlink.h, etc.
-# GENL_LIBRARIES - List of libraries when using genl.
-# GENL_FOUND - True if genl found.
-
-find_path(GENL_INCLUDE_DIR NAMES netlink/netlink.h PATH_SUFFIXES libnl3)
-
-find_library(LIBNL_LIB nl-3)
-find_library(LIBNL_GENL_LIB nl-genl-3)
-set(GENL_LIBRARIES
-  ${LIBNL_LIB}
-  ${LIBNL_GENL_LIB}
-  )
-
-include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(nl-genl-3
-  DEFAULT_MSG GENL_LIBRARIES GENL_INCLUDE_DIR)
-
-mark_as_advanced(
-  GENL_LIBRARIES
-  GENL_INCLUDE_DIR)

cmake/modules/Findnl.cmake

@@ -0,0 +1,50 @@
+# - Find libnl
+# Find the libnl-3 library and includes
+#
+# nl_INCLUDE_DIR - where to find netlink.h, etc.
+# nl_<COMPONENT>_LIBRARY - library when using nl::<COMPONENT>.
+# nl_FOUND - True if nl found.
+
+find_path(nl_INCLUDE_DIR
+  NAMES
+    netlink/netlink.h
+  PATH_SUFFIXES
+    libnl3)
+
+foreach(component "core" ${nl_FIND_COMPONENTS})
+  set(nl_COMPONENTS core cli genl idiag nf route xfrm)
+  list(FIND nl_COMPONENTS "${component}" found)
+  if(found EQUAL -1)
+    message(FATAL_ERROR "unknown libnl-3 component: ${component}")
+  endif()
+  if(component STREQUAL "core")
+    find_library(nl_${component}_LIBRARY nl-3)
+  else()
+    find_library(nl_${component}_LIBRARY nl-${component}-3)
+  endif()
+  list(APPEND nl_LIBRARIES "nl_${component}_LIBRARY")
+endforeach()
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(nl
+  DEFAULT_MSG ${nl_LIBRARIES} nl_INCLUDE_DIR)
+
+mark_as_advanced(
+  ${nl_LIBRARIES}
+  nl_INCLUDE_DIR)
+
+if(nl_FOUND)
+  foreach(component "core" ${nl_FIND_COMPONENTS})
+    if(NOT TARGET nl::${component})
+      add_library(nl::${component} UNKNOWN IMPORTED)
+      set_target_properties(nl::${component} PROPERTIES
+        INTERFACE_INCLUDE_DIRECTORIES "${nl_INCLUDE_DIR}"
+        IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+        IMPORTED_LOCATION "${nl_${component}_LIBRARY}")
+      if(NOT component STREQUAL "core")
+        set_target_properties(nl::${component} PROPERTIES
+          INTERFACE_LINK_LIBRARIES "${nl_core_LIBRARY}")
+      endif()
+    endif()
+  endforeach()
+endif()

debian/control

@@ -53,7 +53,6 @@ Build-Depends: cmake (>= 3.5),
                libssl-dev,
                libtool,
                libudev-dev,
-               libnl-3-dev,
                libnl-genl-3-dev,
                libxml2-dev,
 # Crimson      libyaml-cpp-dev,

src/tools/rbd_nbd/CMakeLists.txt

@@ -1,4 +1,4 @@
+find_package(nl REQUIRED genl)
 add_executable(rbd-nbd rbd-nbd.cc)
-target_include_directories(rbd-nbd PUBLIC ${GENL_INCLUDE_DIR})
-target_link_libraries(rbd-nbd librbd librados global ${GENL_LIBRARIES})
+target_link_libraries(rbd-nbd librbd librados global nl::genl)
 install(TARGETS rbd-nbd DESTINATION bin)