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-rw-r--r--gl/m4/alloca.m486
1 files changed, 80 insertions, 6 deletions
diff --git a/gl/m4/alloca.m4 b/gl/m4/alloca.m4
index f3ee3438..270abd0c 100644
--- a/gl/m4/alloca.m4
+++ b/gl/m4/alloca.m4
@@ -1,5 +1,5 @@
1# alloca.m4 serial 9 1# alloca.m4 serial 14
2dnl Copyright (C) 2002-2004, 2006-2007, 2009-2010 Free Software Foundation, 2dnl Copyright (C) 2002-2004, 2006-2007, 2009-2013 Free Software Foundation,
3dnl Inc. 3dnl Inc.
4dnl This file is free software; the Free Software Foundation 4dnl This file is free software; the Free Software Foundation
5dnl gives unlimited permission to copy and/or distribute it, 5dnl gives unlimited permission to copy and/or distribute it,
@@ -7,10 +7,6 @@ dnl with or without modifications, as long as this notice is preserved.
7 7
8AC_DEFUN([gl_FUNC_ALLOCA], 8AC_DEFUN([gl_FUNC_ALLOCA],
9[ 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]) 10 AC_REQUIRE([AC_FUNC_ALLOCA])
15 if test $ac_cv_func_alloca_works = no; then 11 if test $ac_cv_func_alloca_works = no; then
16 gl_PREREQ_ALLOCA 12 gl_PREREQ_ALLOCA
@@ -40,8 +36,86 @@ AC_DEFUN([gl_FUNC_ALLOCA],
40 ALLOCA_H=alloca.h 36 ALLOCA_H=alloca.h
41 fi 37 fi
42 AC_SUBST([ALLOCA_H]) 38 AC_SUBST([ALLOCA_H])
39 AM_CONDITIONAL([GL_GENERATE_ALLOCA_H], [test -n "$ALLOCA_H"])
43]) 40])
44 41
45# Prerequisites of lib/alloca.c. 42# Prerequisites of lib/alloca.c.
46# STACK_DIRECTION is already handled by AC_FUNC_ALLOCA. 43# STACK_DIRECTION is already handled by AC_FUNC_ALLOCA.
47AC_DEFUN([gl_PREREQ_ALLOCA], [:]) 44AC_DEFUN([gl_PREREQ_ALLOCA], [:])
45
46# This works around a bug in autoconf <= 2.68.
47# See <http://lists.gnu.org/archive/html/bug-gnulib/2011-06/msg00277.html>.
48
49m4_version_prereq([2.69], [] ,[
50
51# This is taken from the following Autoconf patch:
52# http://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=6cd9f12520b0d6f76d3230d7565feba1ecf29497
53
54# _AC_LIBOBJ_ALLOCA
55# -----------------
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.
59m4_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.
64AC_LIBSOURCES(alloca.c)
65AC_SUBST([ALLOCA], [\${LIBOBJDIR}alloca.$ac_objext])dnl
66AC_DEFINE(C_ALLOCA, 1, [Define to 1 if using 'alloca.c'.])
67
68AC_CACHE_CHECK(whether 'alloca.c' needs Cray hooks, ac_cv_os_cray,
69[AC_EGREP_CPP(webecray,
70[#if defined CRAY && ! defined CRAY2
71webecray
72#else
73wenotbecray
74#endif
75], ac_cv_os_cray=yes, ac_cv_os_cray=no)])
76if 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.])
84 break])
85 done
86fi
87
88AC_CACHE_CHECK([stack direction for C alloca],
89 [ac_cv_c_stack_direction],
90[AC_RUN_IFELSE([AC_LANG_SOURCE(
91[AC_INCLUDES_DEFAULT
92int
93find_stack_direction (int *addr, int depth)
94{
95 int dir, dummy = 0;
96 if (! addr)
97 addr = &dummy;
98 *addr = addr < &dummy ? 1 : addr == &dummy ? 0 : -1;
99 dir = depth ? find_stack_direction (addr, depth - 1) : 0;
100 return dir + dummy;
101}
102
103int
104main (int argc, char **argv)
105{
106 return find_stack_direction (0, argc + !argv + 20) < 0;
107}])],
108 [ac_cv_c_stack_direction=1],
109 [ac_cv_c_stack_direction=-1],
110 [ac_cv_c_stack_direction=0])])
111AH_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
119AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction)
120])# _AC_LIBOBJ_ALLOCA
121])