alloca.m4

来自「制作2.6内核的CLFS时 使用的diffutils-2.8.7.tar.gz包」· M4 代码 · 共 35 行

# alloca.m4 serial 3
dnl Copyright (C) 2002-2003 Free Software Foundation, Inc.
dnl This file is free software, distributed under the terms of the GNU
dnl General Public License.  As a special exception to the GNU General
dnl Public License, this file may be distributed as part of a program
dnl that contains a configuration script generated by Autoconf, under
dnl the same distribution terms as the rest of that program.

AC_DEFUN([gl_FUNC_ALLOCA],
[
  dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57.
  AC_REQUIRE([AC_PROG_CPP])
  AC_REQUIRE([AC_PROG_EGREP])

  AC_REQUIRE([AC_FUNC_ALLOCA])
  if test $ac_cv_func_alloca_works = no; then
    gl_PREREQ_ALLOCA
  fi

  # Define an additional variable used in the Makefile substitution.

  AC_EGREP_CPP([Need own alloca], [
#if defined __GNUC__ || defined _MSC_VER || !HAVE_ALLOCA_H
  Need own alloca
#endif
    ],
    ALLOCA_H=alloca.h,
    ALLOCA_H=)
  AC_SUBST([ALLOCA_H])
])

# Prerequisites of lib/alloca.c.
# STACK_DIRECTION is already handled by AC_FUNC_ALLOCA.
AC_DEFUN([gl_PREREQ_ALLOCA], [:])