From 031e79e77e4bc4c2dda3327a4f3a5ba637723ff4 Mon Sep 17 00:00:00 2001
From: Pavel Labath <pavelo@centrum.sk>
Date: Fri, 30 Sep 2011 23:01:24 +0200
Subject: [PATCH] Fix linking error: clock_gettime not found

I decided to reimplement AC_SEARCH_LIB from autotools in the process, as I consider it a very
nifty feature.
---
 cmake/Conky.cmake               | 22 ++++++++++++++++++++++
 cmake/ConkyPlatformChecks.cmake |  7 +++++++
 2 files changed, 29 insertions(+)

diff --git a/cmake/Conky.cmake b/cmake/Conky.cmake
index d9910ed6..6b528fc1 100644
--- a/cmake/Conky.cmake
+++ b/cmake/Conky.cmake
@@ -61,6 +61,7 @@ set(conky_libs ${CMAKE_THREAD_LIBS_INIT})
 set(conky_includes ${CMAKE_BINARY_DIR})
 
 add_definitions(-D_GNU_SOURCE) # Standard definitions
+set(CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS} -D_GNU_SOURCE")
 
 # Do version stuff
 set(VERSION_MAJOR "2")
@@ -112,3 +113,24 @@ endif(RELEASE)
 
 set(COPYRIGHT "Copyright Brenden Matthews, et al, 2005-2010")
 
+macro(AC_SEARCH_LIBS FUNCTION_NAME INCLUDES TARGET_VAR)
+	if("${TARGET_VAR}" MATCHES "^${TARGET_VAR}$")
+		unset(AC_SEARCH_LIBS_TMP CACHE)
+		check_symbol_exists(${FUNCTION_NAME} ${INCLUDES} AC_SEARCH_LIBS_TMP)
+		if(${AC_SEARCH_LIBS_TMP})
+			set(${TARGET_VAR} "" CACHE INTERNAL "Library containing ${FUNCTION_NAME}")
+			return()
+		endif(${AC_SEARCH_LIBS_TMP})
+
+		foreach(LIB ${ARGN})
+			unset(AC_SEARCH_LIBS_TMP CACHE)
+			unset(AC_SEARCH_LIBS_FOUND CACHE)
+			find_library(AC_SEARCH_LIBS_TMP ${LIB})
+			check_library_exists(${LIB} ${FUNCTION_NAME} ${AC_SEARCH_LIBS_TMP} AC_SEARCH_LIBS_FOUND)
+			if(${AC_SEARCH_LIBS_FOUND})
+				set(${TARGET_VAR} ${AC_SEARCH_LIBS_TMP} CACHE INTERNAL "Library containing ${FUNCTION_NAME}")
+				break()
+			endif(${AC_SEARCH_LIBS_FOUND})
+		endforeach(LIB)
+	endif("${TARGET_VAR}" MATCHES "^${TARGET_VAR}$")
+endmacro(AC_SEARCH_LIBS)
diff --git a/cmake/ConkyPlatformChecks.cmake b/cmake/ConkyPlatformChecks.cmake
index 38159525..959555fd 100644
--- a/cmake/ConkyPlatformChecks.cmake
+++ b/cmake/ConkyPlatformChecks.cmake
@@ -23,6 +23,7 @@
 include(FindPkgConfig)
 include(CheckFunctionExists)
 include(CheckIncludeFile)
+include(CheckSymbolExists)
 
 # Check for some headers
 check_include_files(sys/statfs.h HAVE_SYS_STATFS_H)
@@ -33,6 +34,12 @@ check_include_files(dirent.h HAVE_DIRENT_H)
 # Check for some functions
 check_function_exists(strndup HAVE_STRNDUP)
 
+AC_SEARCH_LIBS(clock_gettime "time.h" CLOCK_GETTIME_LIB "rt")
+if(NOT CLOCK_GETTIME_LIB)
+	message(FATAL_ERROR "clock_gettime not found.")
+endif(NOT CLOCK_GETTIME_LIB)
+set(conky_libs ${conky_libs} ${CLOCK_GETTIME_LIB})
+
 # standard path to search for includes
 set(INCLUDE_SEARCH_PATH /usr/include /usr/local/include)