1 files changed, 16 insertions, 29 deletions

diff --git a/gl/m4/alloca.m4 b/gl/m4/alloca.m4
index 270abd0..ba2f679 100644
--- a/gl/m4/alloca.m4
+++ b/gl/m4/alloca.m4
@@ -1,5 +1,5 @@
-# alloca.m4 serial 14
-dnl Copyright (C) 2002-2004, 2006-2007, 2009-2013 Free Software Foundation,
+# alloca.m4 serial 20
+dnl Copyright (C) 2002-2004, 2006-2007, 2009-2021 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,
@@ -37,19 +37,26 @@ AC_DEFUN([gl_FUNC_ALLOCA],
   fi
   AC_SUBST([ALLOCA_H])
   AM_CONDITIONAL([GL_GENERATE_ALLOCA_H], [test -n "$ALLOCA_H"])
+
+  if test $ac_cv_working_alloca_h = yes; then
+    HAVE_ALLOCA_H=1
+  else
+    HAVE_ALLOCA_H=0
+  fi
+  AC_SUBST([HAVE_ALLOCA_H])
 ])
 
 # Prerequisites of lib/alloca.c.
 # STACK_DIRECTION is already handled by AC_FUNC_ALLOCA.
 AC_DEFUN([gl_PREREQ_ALLOCA], [:])
 
-# This works around a bug in autoconf <= 2.68.
-# See <http://lists.gnu.org/archive/html/bug-gnulib/2011-06/msg00277.html>.
+m4_version_prereq([2.70], [], [
 
-m4_version_prereq([2.69], [] ,[
-
-# This is taken from the following Autoconf patch:
-# http://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=6cd9f12520b0d6f76d3230d7565feba1ecf29497
+# This works around a bug in autoconf <= 2.68 and has simplifications
+# from 2.70.  See:
+# https://lists.gnu.org/r/bug-gnulib/2011-06/msg00277.html
+# https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=6cd9f12520b0d6f76d3230d7565feba1ecf29497
+# https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=15edf7fd8094fd14a89d9891dd72a9624762597a
 
 # _AC_LIBOBJ_ALLOCA
 # -----------------
@@ -65,26 +72,6 @@ AC_LIBSOURCES(alloca.c)
 AC_SUBST([ALLOCA], [\${LIBOBJDIR}alloca.$ac_objext])dnl
 AC_DEFINE(C_ALLOCA, 1, [Define to 1 if using 'alloca.c'.])
 
-AC_CACHE_CHECK(whether 'alloca.c' needs Cray hooks, ac_cv_os_cray,
-[AC_EGREP_CPP(webecray,
-[#if defined CRAY && ! defined CRAY2
-webecray
-#else
-wenotbecray
-#endif
-], ac_cv_os_cray=yes, ac_cv_os_cray=no)])
-if test $ac_cv_os_cray = yes; then
-  for ac_func in _getb67 GETB67 getb67; do
-    AC_CHECK_FUNC($ac_func,
-                  [AC_DEFINE_UNQUOTED(CRAY_STACKSEG_END, $ac_func,
-                                      [Define to one of '_getb67', 'GETB67',
-                                       'getb67' for Cray-2 and Cray-YMP
-                                       systems. This function is required for
-                                       'alloca.c' support on those systems.])
-    break])
-  done
-fi
-
 AC_CACHE_CHECK([stack direction for C alloca],
                [ac_cv_c_stack_direction],
 [AC_RUN_IFELSE([AC_LANG_SOURCE(
@@ -115,7 +102,7 @@ AH_VERBATIM([STACK_DIRECTION],
         STACK_DIRECTION > 0 => grows toward higher addresses
         STACK_DIRECTION < 0 => grows toward lower addresses
         STACK_DIRECTION = 0 => direction of growth unknown */
-@%:@undef STACK_DIRECTION])dnl
+#undef STACK_DIRECTION])dnl
 AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction)
 ])# _AC_LIBOBJ_ALLOCA
 ])