# alloca.m4 serial 9

dnl Copyright (C) 2002-2004, 2006-2007, 2009-2010 Free Software Foundation,

dnl Inc.

dnl This file is free software; the Free Software Foundation

dnl gives unlimited permission to copy and/or distribute it,

dnl with or without modifications, as long as this notice is preserved.

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.

if test $ac_cv_working_alloca_h = yes; then

AC_CACHE_CHECK([for alloca as a compiler built-in], [gl_cv_rpl_alloca], [

AC_EGREP_CPP([Need own alloca], [

#if defined __GNUC__ || defined _AIX || defined _MSC_VER

Need own alloca

#endif

], [gl_cv_rpl_alloca=yes], [gl_cv_rpl_alloca=no])

])

if test $gl_cv_rpl_alloca = yes; then

dnl OK, alloca can be implemented through a compiler built-in.

AC_DEFINE([HAVE_ALLOCA], [1],

[Define to 1 if you have 'alloca' after including <alloca.h>,

a header that may be supplied by this distribution.])

ALLOCA_H=alloca.h

else

dnl alloca exists as a library function, i.e. it is slow and probably

dnl a memory leak. Don't define HAVE_ALLOCA in this case.

ALLOCA_H=

fi

else

ALLOCA_H=alloca.h

fi

AC_SUBST([ALLOCA_H])

])

# Prerequisites of lib/alloca.c.

# STACK_DIRECTION is already handled by AC_FUNC_ALLOCA.

AC_DEFUN([gl_PREREQ_ALLOCA], [:])