view m4/strings_h.m4 @ 15390:25fd80a52583

ffs: new module Libvirt wants to use ffs() to avoid dragging in -lm for log2(). * modules/ffs: New file. * m4/ffs.m4: Likewise. * lib/ffs.c: Likewise. * m4/strings_h.m4 (gl_HEADER_STRINGS_H_DEFAULTS): Add default. * modules/strings (Makefile.am): Substitute witness. (Depends-on): Add c++defs. * lib/strings.in.h (ffs): Declare. * modules/ffs-tests: New test file. * tests/test-ffs.c: Test new module. * MODULES.html.sh (Integer arithmetic functions): Mention it. * doc/posix-functions/ffs.texi (ffs): Likewise. Signed-off-by: Eric Blake <eblake@redhat.com>
author Eric Blake <eblake@redhat.com>
date Mon, 11 Jul 2011 17:05:34 -0600
parents 97fc9a21a8fb
children d9061bf1cead
line wrap: on
line source

# Configure a replacement for <strings.h>.
# serial 4

# Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_HEADER_STRINGS_H],
[
  dnl Use AC_REQUIRE here, so that the default behavior below is expanded
  dnl once only, before all statements that occur in other macros.
  AC_REQUIRE([gl_HEADER_STRINGS_H_BODY])
])

AC_DEFUN([gl_HEADER_STRINGS_H_BODY],
[
  AC_REQUIRE([gl_HEADER_STRINGS_H_DEFAULTS])
  gl_CHECK_NEXT_HEADERS([strings.h])

  dnl Check for declarations of anything we want to poison if the
  dnl corresponding gnulib module is not in use.
  gl_WARN_ON_USE_PREPARE([[#include <strings.h>
    ]], [ffs strcasecmp strncasecmp])
])

AC_DEFUN([gl_STRINGS_MODULE_INDICATOR],
[
  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
  AC_REQUIRE([gl_HEADER_STRINGS_H_DEFAULTS])
  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
])

AC_DEFUN([gl_HEADER_STRINGS_H_DEFAULTS],
[
  GNULIB_FFS=0;            AC_SUBST([GNULIB_FFS])
  dnl Assume proper GNU behavior unless another module says otherwise.
  HAVE_FFS=1;              AC_SUBST([HAVE_FFS])
  HAVE_STRCASECMP=1;       AC_SUBST([HAVE_STRCASECMP])
  HAVE_DECL_STRNCASECMP=1; AC_SUBST([HAVE_DECL_STRNCASECMP])
])