#2 Issue compiling (Linux/Boost 1.55)

[Jean-Francois]

Hi,

Had trouble compiling with Linux and boost 1.55. Linker complains about undefined references to clock_gettime.

Exact error message is:
cd /home/jbeaulac/mgizapp/mgizapp-updated-0.7.3/src && /usr/local/bin/cmake -E cmake_link_script CMakeFiles/mgiza.dir/link.txt --verbose=1
/usr/bin/c++ CMakeFiles/mgiza.dir/main.cpp.o -o ../bin/mgiza -L/opt/boost-1.55/lib64 -L/home/jbeaulac/mgizapp/mgizapp-updated-0.7.3/lib -rdynamic ../lib/libmgiza.a /opt/boost-1.55/lib64/libboost_thread.a /opt/boost-1.55/lib64/libboost_system.a -lpthread -Wl,-rpath,/opt/boost-1.55/lib64:/home/jbeaulac/mgizapp/mgizapp-updated-0.7.3/lib:
/opt/boost-1.55/lib64/libboost_thread.a(thread.o): In function boost::this_thread::hiden::sleep_until(timespec const&)': thread.cpp:(.text+0x20cb): undefined reference toclock_gettime'
thread.cpp:(.text+0x2141): undefined reference to clock_gettime' thread.cpp:(.text+0x21ac): undefined reference toclock_gettime'
thread.cpp:(.text+0x2217): undefined reference to clock_gettime' thread.cpp:(.text+0x2282): undefined reference toclock_gettime'
/opt/boost-1.55/lib64/libboost_thread.a(thread.o):thread.cpp:(.text+0x22ed): more undefined references to `clock_gettime' follow

I added the following in src/CMakeList.txt, ran cmake again and it then compiled successfully

if(UNIX AND NOT APPLE)
target_link_libraries(mgiza rt)
endif()
if(UNIX AND NOT APPLE)
target_link_libraries(hmmnorm rt)
endif()
if(UNIX AND NOT APPLE)
target_link_libraries(d4norm rt)
endif()

[Jean-Francois]

Think I found out why I had this issue, some Boost.Thread functions use Boost.Chrono starting with Boost 1.50.0:
http://www.boost.org/doc/libs/1_55_0/doc/html/thread/time.html

I attached a patch of a fix that probably makes sense. Tested with linux with boost 1.55 and boost 1.41 and it compiles.

diff -ur -x CMakeList.txt ../original-0.7.3//CMakeLists.txt ./CMakeLists.txt
--- ../original-0.7.3//CMakeLists.txt   2013-06-23 14:38:59.000000000 -0400
+++ ./CMakeLists.txt    2014-03-18 00:17:42.000000000 -0400
@@ -46,7 +46,7 @@
 set(Boost_USE_STATIC_RUNTIME    OFF)


-FIND_PACKAGE( Boost 1.41 COMPONENTS thread)
+FIND_PACKAGE( Boost 1.41 COMPONENTS thread system)

  IF(Boost_FOUND)
     IF (NOT _boost_IN_CACHE)
diff -ur -x CMakeList.txt ../original-0.7.3//src/CMakeLists.txt ./src/CMakeLists.txt
--- ../original-0.7.3//src/CMakeLists.txt   2013-06-23 14:38:58.000000000 -0400
+++ ./src/CMakeLists.txt    2014-03-18 00:15:30.000000000 -0400
@@ -75,9 +75,15 @@
    ELSE( USE_64_BIT )
        SET(CMAKE_THREAD_LIBS_INIT pthread)
    ENDIF(  )
+# if boost > 1.50, some boost_thread code could require chrono, which needs librt
+ELSEIF(Boost_VERSION VERSION_GREATER "104900")

+   IF (CMAKE_SYSTEM MATCHES "Linux")
+       SET(CMAKE_THREAD_LIBS_INIT ${CMAKE_THREAD_LIBS_INIT} rt)
+   ENDIF()
+ENDIF()


-   
-ENDIF()    
 INCLUDE_DIRECTORIES( ${PROJECT_SOURCE_DIR}/src/ )
 LINK_DIRECTORIES ( ${LIBRARY_OUTPUT_PATH} )