From de4fbf92d0da17e2c7f31df29bc72c44702b4e7c Mon Sep 17 00:00:00 2001
From: Rich Wareham <rjw57@cam.ac.uk>
Date: Wed, 26 Feb 2014 10:06:59 +0000
Subject: [PATCH] link to rt if it provides clock_gettime

As noted in #128, if clock_gettime is provided by librt then it does not
end up being linked into the static libuv.a binary. This might be
considered a bug in libuv but we can address it here.

Detect if librt provides the clock_gettime symbol and, if so, append it
to the list of libraries linked into nvim. On non-librt systems the
behaviour should be as before.
---
 CMakeLists.txt     |  9 ++++++++-
 src/CMakeLists.txt | 13 +++++++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b057a67f69..04df162f07 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -18,6 +18,9 @@ else()
   set(DEBUG 0)
 endif()
 
+# Modules used by platform auto-detection
+include(CheckLibraryExists)
+
 # Determine platform's threading library. Set CMAKE_THREAD_PREFER_PTHREAD
 # explicitly to indicate a strong preference for pthread. It is an error to not
 # have pthread installed even if, for example, the Win32 threading API is found.
@@ -27,11 +30,15 @@ if(NOT CMAKE_USE_PTHREADS_INIT)
   message(SEND_ERROR "The pthread library must be installed on your system.")
 endif(NOT CMAKE_USE_PTHREADS_INIT)
 
+# Detect if clock_gettime exists in -lrt. If so we need to link with it because
+# the static libuv doesn't but uses clock_gettime.
+check_library_exists(rt clock_gettime "time.h" HAVE_CLOCK_GETTIME)
+
 # Require libuv
 find_package(LibUV REQUIRED)
 include_directories(${LibUV_INCLUDE_DIRS})
 
-include_directories ("${PROJECT_BINARY_DIR}/config") 
+include_directories ("${PROJECT_BINARY_DIR}/config")
 
 set (CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 96c0b01f3d..a7e815fd7c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -14,7 +14,16 @@ file( GLOB OS_SOURCES os/*.c )
 
 add_executable (nvim ${NEOVIM_SOURCES} ${OS_SOURCES})
 
-target_link_libraries (vim m ${LibUV_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})
+# The libraries we link against for nvim
+set(NVIM_LINK_LIBRARIES m ${LibUV_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})
+
+# Add any libraries needed for a specific platform
+if(HAVE_CLOCK_GETTIME)
+  # Work around libuv.a not linking in rt.
+  list(APPEND NVIM_LINK_LIBRARIES rt)
+endif(HAVE_CLOCK_GETTIME)
+
+target_link_libraries (nvim ${NVIM_LINK_LIBRARIES})
 
 include(CheckLibraryExists)
 check_library_exists(termcap tgetent "" HAVE_LIBTERMCAP)
@@ -30,6 +39,6 @@ else()
   endif()
 endif()
 
-include_directories ("${PROJECT_SOURCE_DIR}/src/proto") 
+include_directories ("${PROJECT_SOURCE_DIR}/src/proto")
 
 install(TARGETS nvim RUNTIME DESTINATION bin)