|
434
|
1 # alloca.m4 serial 9
|
|
|
2 dnl Copyright (C) 2002-2004, 2006-2007, 2009-2010 Free Software Foundation,
|
|
|
3 dnl Inc.
|
|
|
4 dnl This file is free software; the Free Software Foundation
|
|
|
5 dnl gives unlimited permission to copy and/or distribute it,
|
|
|
6 dnl with or without modifications, as long as this notice is preserved.
|
|
|
7
|
|
|
8 AC_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.
|
|
|
47 AC_DEFUN([gl_PREREQ_ALLOCA], [:])
|
