xref: /netbsd-src/external/gpl2/xcvs/dist/m4/clock_time.m4 (revision a7c918477dd5f12c1da816ba05caf44eab2d06d6)
1# clock_time.m4 serial 6
2dnl Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7# Check for clock_gettime and clock_settime, and sets LIB_CLOCK_GETTIME.
8AC_DEFUN([gl_CLOCK_TIME],
9[
10  # dnl Persuade glibc <time.h> to declare these functions.
11  AC_REQUIRE([AC_GNU_SOURCE])
12
13  # Solaris 2.5.1 needs -lposix4 to get the clock_gettime function.
14  # Solaris 7 prefers the library name -lrt to the obsolescent name -lposix4.
15
16  # Save and restore LIBS so e.g., -lrt, isn't added to it.  Otherwise, *all*
17  # programs in the package would end up linked with that potentially-shared
18  # library, inducing unnecessary run-time overhead.
19  gl_saved_libs=$LIBS
20    AC_SEARCH_LIBS(clock_gettime, [rt posix4],
21                   [test "$ac_cv_search_clock_gettime" = "none required" ||
22                    LIB_CLOCK_GETTIME=$ac_cv_search_clock_gettime])
23    AC_SUBST(LIB_CLOCK_GETTIME)
24    AC_CHECK_FUNCS(clock_gettime clock_settime)
25  LIBS=$gl_saved_libs
26])
27