ObjFW  Check-in [84dd396274]

#
#   This macro figures out how to build C programs using POSIX threads. It
#   sets the PTHREAD_LIBS output variable to the threads library and linker
#   flags, and the PTHREAD_CFLAGS output variable to any special C compiler
#   flags that are needed. (The user can also force certain compiler
#   flags/libs to be tested by setting these environment variables.)
#
#   Also sets PTHREAD_CC to any special C compiler that is needed for
#   multi-threaded programs (defaults to the value of CC otherwise). (This
#   is necessary on AIX to use the special cc_r compiler alias.)
#
#   NOTE: You are assumed to not only compile your program with these flags,
#   but also link it with them as well. e.g. you should link with
#   $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS
#
#   If you are only building threads programs, you may wish to use these
#   variables in your default LIBS, CFLAGS, and CC:
#
#          LIBS="$PTHREAD_LIBS $LIBS"
#          CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
#          CC="$PTHREAD_CC"
#
#   In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant
#   has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to that name
#   (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
#
#   ACTION-IF-FOUND is a list of shell commands to run if a threads library
#   is found, and ACTION-IF-NOT-FOUND is a list of commands to run it if it

#   This special exception to the GPL applies to versions of the Autoconf
#   Macro released by the Autoconf Macro Archive. When you make and
#   distribute a modified version of the Autoconf Macro, you may extend this
#   special exception to the GPL to apply to your modified version as well.

AC_DEFUN([ACX_PTHREAD], [
AC_REQUIRE([AC_CANONICAL_HOST])
AC_LANG_SAVE
AC_LANG_OBJC
acx_pthread_ok=no

# We used to check for pthread.h first, but this fails if pthread.h
# requires special compiler flags (e.g. on True64 or Sequent).
# It gets checked for in the link test anyway.

# First of all, check if the user has set any of the PTHREAD_LIBS,

        AC_MSG_RESULT(${flag})
        if test "x$flag" != xno; then
            PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
        fi

        LIBS="$save_LIBS"
        CFLAGS="$save_CFLAGS"

        # More AIX lossage: must compile with xlc_r or cc_r
	if test x"$GCC" != xyes; then
          AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
        else
          PTHREAD_CC=$CC
	fi
else
        PTHREAD_CC="$CC"
fi

AC_SUBST(PTHREAD_LIBS)
AC_SUBST(PTHREAD_CFLAGS)
AC_SUBST(PTHREAD_CC)

# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
if test x"$acx_pthread_ok" = xyes; then
        ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
        :
else
        acx_pthread_ok=no
        $2
fi
AC_LANG_RESTORE
])dnl ACX_PTHREAD