include(CheckCCompilerFlag)
include(CheckCSourceCompiles)
include(CheckPrototypeDefinition)
include(CheckSymbolExists)
include(CheckTypeSize)
set(CMAKE_REQUIRED_DEFINITIONS "-D_GNU_SOURCE")

if(ARCH_X86 OR ARCH_X86_64)
  check_c_compiler_flag("-mpclmul" HAVE_PCLMUL)
endif(ARCH_X86 OR ARCH_X86_64)



if(ENABLE_LTO)
  set(CFLAGS_LTO "-flto")
  set(CFLAGS_NO_LTO "-fno-lto")

  check_c_compiler_flag("-fwhole-program" HAVE_FLAG_WHOLE_PROGRAM)
  if(HAVE_FLAG_WHOLE_PROGRAM)
    set(LDFLAGS_LTO "-flto -fwhole-program")
  else(HAVE_FLAG_WHOLE_PROGRAM)
    set(LDFLAGS_LTO "-flto")
  endif(HAVE_FLAG_WHOLE_PROGRAM)
endif(ENABLE_LTO)


check_c_source_compiles("
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>

int main() {
	return AI_ADDRCONFIG;
}
" HAVE_AI_ADDRCONFIG)


check_prototype_definition("get_current_dir_name" "char *get_current_dir_name(void)" "NULL" "unistd.h" HAVE_GET_CURRENT_DIR_NAME)


set(RT_LIBRARY "")
check_symbol_exists("clock_gettime" "time.h" HAVE_CLOCK_GETTIME)

if(NOT HAVE_CLOCK_GETTIME)
  set(RT_LIBRARY "rt")
  list(APPEND CMAKE_REQUIRED_LIBRARIES "rt")

  check_symbol_exists("clock_gettime" "time.h" HAVE_CLOCK_GETTIME_RT)
  if(NOT HAVE_CLOCK_GETTIME_RT)
      message(FATAL_ERROR "clock_gettime() not found")
  endif(NOT HAVE_CLOCK_GETTIME_RT)
endif(NOT HAVE_CLOCK_GETTIME)


set(CMAKE_EXTRA_INCLUDE_FILES "netinet/if_ether.h")
check_type_size("struct ethhdr" SIZEOF_ETHHDR)
string(COMPARE NOTEQUAL "${SIZEOF_ETHHDR}" "" HAVE_ETHHDR)