Query llvm-config to get system libs required for linking.

Remove the unused function get_system_libs. Instead, run
'llvm-config --system-libs' to determine which libraries are required in
addition LLVM's for linking an executable. At the moment these are the unittests
that link to gtest and transitively depend on these system libs.

llvm-svn: 279743

Author: Meinersbur

polly/CMakeLists.txt

@@ -21,22 +21,10 @@ if (NOT DEFINED LLVM_MAIN_SRC_DIR)
   include_directories(${LLVM_INSTALL_ROOT}/include/)
 
   # Get the system librarys that will link into LLVM.
-  function(get_system_libs return_var)
-    # Returns in `return_var' a list of system libraries used by LLVM.
-    if( NOT MSVC )
-      if( MINGW )
-        set(system_libs ${system_libs} imagehlp psapi)
-      elseif( CMAKE_HOST_UNIX )
-        if( HAVE_LIBDL )
-          set(system_libs ${system_libs} ${CMAKE_DL_LIBS})
-        endif()
-        if( LLVM_ENABLE_THREADS AND HAVE_LIBPTHREAD )
-          set(system_libs ${system_libs} pthread)
-        endif()
-      endif( MINGW )
-    endif( NOT MSVC )
-    set(${return_var} ${system_libs} PARENT_SCOPE)
-  endfunction(get_system_libs)
+  execute_process(COMMAND "${LLVM_INSTALL_ROOT}/bin/llvm-config" --system-libs
+                  OUTPUT_VARIABLE LLVM_SYSTEM_LIBS
+                  OUTPUT_STRIP_TRAILING_WHITESPACE)
+  message(STATUS "System libs required by LLVM: ${LLVM_SYSTEM_LIBS}")
 
   # Determine where LLVM stores its libraries.
   execute_process(COMMAND "${LLVM_INSTALL_ROOT}/bin/llvm-config" --libdir
@@ -100,9 +88,7 @@ if (NOT DEFINED LLVM_MAIN_SRC_DIR)
   if(EXISTS ${UNITTEST_DIR}/googletest/include/gtest/gtest.h)
     add_library(gtest ${UNITTEST_DIR}/googletest/src/gtest-all.cc)
     target_include_directories(gtest PUBLIC "${UNITTEST_DIR}/googletest/include" PRIVATE "${UNITTEST_DIR}/googletest")
-    if( NOT MSVC )
-      target_link_libraries(gtest pthread tinfo dl)
-    endif ()
+    target_link_libraries(gtest ${LLVM_SYSTEM_LIBS})
 
     add_library(gtest_main ${UNITTEST_DIR}/UnitTestMain/TestMain.cpp)
     target_link_libraries(gtest_main gtest)