1# alloca.m4 serial 9 2dnl Copyright (C) 2002-2004, 2006-2007, 2009-2010 Free Software Foundation, 3dnl Inc. 4dnl This file is free software; the Free Software Foundation 5dnl gives unlimited permission to copy and/or distribute it, 6dnl with or without modifications, as long as this notice is preserved. 7 8AC_DEFUN([gl_FUNC_ALLOCA], 9[ 10 dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57. 11 AC_REQUIRE([AC_PROG_CPP]) 12 AC_REQUIRE([AC_PROG_EGREP]) 13 14 AC_REQUIRE([AC_FUNC_ALLOCA]) 15 if test $ac_cv_func_alloca_works = no; then 16 gl_PREREQ_ALLOCA 17 fi 18 19 # Define an additional variable used in the Makefile substitution. 20 if test $ac_cv_working_alloca_h = yes; then 21 AC_CACHE_CHECK([for alloca as a compiler built-in], [gl_cv_rpl_alloca], [ 22 AC_EGREP_CPP([Need own alloca], [ 23#if defined __GNUC__ || defined _AIX || defined _MSC_VER 24 Need own alloca 25#endif 26 ], [gl_cv_rpl_alloca=yes], [gl_cv_rpl_alloca=no]) 27 ]) 28 if test $gl_cv_rpl_alloca = yes; then 29 dnl OK, alloca can be implemented through a compiler built-in. 30 AC_DEFINE([HAVE_ALLOCA], [1], 31 [Define to 1 if you have 'alloca' after including <alloca.h>, 32 a header that may be supplied by this distribution.]) 33 ALLOCA_H=alloca.h 34 else 35 dnl alloca exists as a library function, i.e. it is slow and probably 36 dnl a memory leak. Don't define HAVE_ALLOCA in this case. 37 ALLOCA_H= 38 fi 39 else 40 ALLOCA_H=alloca.h 41 fi 42 AC_SUBST([ALLOCA_H]) 43]) 44 45# Prerequisites of lib/alloca.c. 46# STACK_DIRECTION is already handled by AC_FUNC_ALLOCA. 47AC_DEFUN([gl_PREREQ_ALLOCA], [:]) 48