2
dnl Copyright (C) 2002-2004, 2006, 2007, 2009 Free Software Foundation, Inc.
2
dnl Copyright (C) 2002-2004, 2006-2007, 2009-2011 Free Software Foundation,
3
4
dnl This file is free software; the Free Software Foundation
4
5
dnl gives unlimited permission to copy and/or distribute it,
5
6
dnl with or without modifications, as long as this notice is preserved.
7
8
AC_DEFUN([gl_FUNC_ALLOCA],
9
dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57.
10
AC_REQUIRE([AC_PROG_CPP])
11
AC_REQUIRE([AC_PROG_EGREP])
13
10
AC_REQUIRE([AC_FUNC_ALLOCA])
14
11
if test $ac_cv_func_alloca_works = no; then
41
38
AC_SUBST([ALLOCA_H])
39
AM_CONDITIONAL([GL_GENERATE_ALLOCA_H], [test -n "$ALLOCA_H"])
44
42
# Prerequisites of lib/alloca.c.
45
43
# STACK_DIRECTION is already handled by AC_FUNC_ALLOCA.
46
44
AC_DEFUN([gl_PREREQ_ALLOCA], [:])
46
# This works around a bug in autoconf <= 2.68.
47
# See <http://lists.gnu.org/archive/html/bug-gnulib/2011-06/msg00277.html>.
49
m4_version_prereq([2.69], [] ,[
51
# This is taken from the following Autoconf patch:
52
# http://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=6cd9f12520b0d6f76d3230d7565feba1ecf29497
56
# Set up the LIBOBJ replacement of `alloca'. Well, not exactly
57
# AC_LIBOBJ since we actually set the output variable `ALLOCA'.
58
# Nevertheless, for Automake, AC_LIBSOURCES it.
59
m4_define([_AC_LIBOBJ_ALLOCA],
60
[# The SVR3 libPW and SVR4 libucb both contain incompatible functions
61
# that cause trouble. Some versions do not even contain alloca or
62
# contain a buggy version. If you still want to use their alloca,
63
# use ar to extract alloca.o from them instead of compiling alloca.c.
64
AC_LIBSOURCES(alloca.c)
65
AC_SUBST([ALLOCA], [\${LIBOBJDIR}alloca.$ac_objext])dnl
66
AC_DEFINE(C_ALLOCA, 1, [Define to 1 if using `alloca.c'.])
68
AC_CACHE_CHECK(whether `alloca.c' needs Cray hooks, ac_cv_os_cray,
69
[AC_EGREP_CPP(webecray,
70
[#if defined CRAY && ! defined CRAY2
75
], ac_cv_os_cray=yes, ac_cv_os_cray=no)])
76
if test $ac_cv_os_cray = yes; then
77
for ac_func in _getb67 GETB67 getb67; do
78
AC_CHECK_FUNC($ac_func,
79
[AC_DEFINE_UNQUOTED(CRAY_STACKSEG_END, $ac_func,
80
[Define to one of `_getb67', `GETB67',
81
`getb67' for Cray-2 and Cray-YMP
82
systems. This function is required for
83
`alloca.c' support on those systems.])
88
AC_CACHE_CHECK([stack direction for C alloca],
89
[ac_cv_c_stack_direction],
90
[AC_RUN_IFELSE([AC_LANG_SOURCE(
93
find_stack_direction (int *addr, int depth)
98
*addr = addr < &dummy ? 1 : addr == &dummy ? 0 : -1;
99
dir = depth ? find_stack_direction (addr, depth - 1) : 0;
104
main (int argc, char **argv)
106
return find_stack_direction (0, argc + !argv + 20) < 0;
108
[ac_cv_c_stack_direction=1],
109
[ac_cv_c_stack_direction=-1],
110
[ac_cv_c_stack_direction=0])])
111
AH_VERBATIM([STACK_DIRECTION],
112
[/* If using the C implementation of alloca, define if you know the
113
direction of stack growth for your system; otherwise it will be
114
automatically deduced at runtime.
115
STACK_DIRECTION > 0 => grows toward higher addresses
116
STACK_DIRECTION < 0 => grows toward lower addresses
117
STACK_DIRECTION = 0 => direction of growth unknown */
118
@%:@undef STACK_DIRECTION])dnl
119
AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction)
120
])# _AC_LIBOBJ_ALLOCA