From 4a65a237067c9f56c2debedf495c40524c1b1a8a Mon Sep 17 00:00:00 2001
From: James Turner <zakalawe@mac.com>
Date: Tue, 19 Jul 2011 13:53:13 +0100
Subject: [PATCH] test linkage needs librt on Linux. Need to tidy this up on
 the FG side.

---
 CMakeLists.txt            | 25 +++++++++++++++++++++++++
 simgear/io/CMakeLists.txt |  4 +++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 73bfdb51..517d87df 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -92,6 +92,31 @@ check_function_exists(ftime HAVE_FTIME)
 check_function_exists(timegm HAVE_TIMEGM)
 check_function_exists(rint HAVE_RINT)
 
+
+if(HAVE_UNISTD_H)
+    set(CMAKE_REQUIRED_INCLUDES ${CMAKE_INCLUDE_PATH})
+    check_cxx_source_compiles(
+       "#include <unistd.h>
+        #if !defined(_POSIX_TIMERS) || (0 >= _POSIX_TIMERS)
+            #error clock_gettime is not supported
+        #endif
+
+        int main() { return 0; }
+        "
+        HAVE_CLOCK_GETTIME)    
+endif(HAVE_UNISTD_H)
+
+set(RT_LIBRARY "")
+if(HAVE_CLOCK_GETTIME)
+    check_function_exists(clock_gettime CLOCK_GETTIME_IN_LIBC)
+    if(NOT CLOCK_GETTIME_IN_LIBC)
+        check_library_exists(rt clock_gettime "" HAVE_RT)
+        if(HAVE_RT)
+            set(RT_LIBRARY rt)
+        endif(HAVE_RT)
+        endif(NOT CLOCK_GETTIME_IN_LIBC)
+endif(HAVE_CLOCK_GETTIME)
+
 SET(CMAKE_DEBUG_POSTFIX "d" CACHE STRING "add a postfix, usually d on windows")
 SET(CMAKE_RELEASE_POSTFIX "" CACHE STRING "add a postfix, usually empty on windows")
 SET(CMAKE_RELWITHDEBINFO_POSTFIX "rd" CACHE STRING "add a postfix, usually empty on windows")
diff --git a/simgear/io/CMakeLists.txt b/simgear/io/CMakeLists.txt
index 1d4600f6..fe0eb6f1 100644
--- a/simgear/io/CMakeLists.txt
+++ b/simgear/io/CMakeLists.txt
@@ -40,5 +40,7 @@ add_executable(test_sock socktest.cxx)
 target_link_libraries(test_sock sgio sgstructure sgdebug)
 
 add_executable(test_http test_HTTP.cxx)
-target_link_libraries(test_http sgio sgstructure sgtiming sgmisc sgdebug)
+target_link_libraries(test_http 
+    sgio sgstructure sgtiming sgmisc sgdebug
+    ${RT_LIBRARY})
 
-- 
2.39.5