diff options
author | Ludovic Courtès <ludo@gnu.org> | 2011-07-01 22:34:29 +0200 |
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committer | Ludovic Courtès <ludo@gnu.org> | 2011-07-01 22:34:29 +0200 |
commit | 231c0e0e61fc4bdd69398e89084b7819f0420710 (patch) | |
tree | 097398cd884074bd1d62dfa592fbdd8eda0d9796 /m4/alloca.m4 | |
parent | 97ec95b72873428f215a8a9892487c3a8435a754 (diff) |
Update Gnulib to v0.0-5874-g7170ee0.
Diffstat (limited to 'm4/alloca.m4')
-rw-r--r-- | m4/alloca.m4 | 79 |
1 files changed, 78 insertions, 1 deletions
diff --git a/m4/alloca.m4 b/m4/alloca.m4 index 689da75a2..891fc8bc3 100644 --- a/m4/alloca.m4 +++ b/m4/alloca.m4 @@ -1,4 +1,4 @@ -# alloca.m4 serial 11 +# alloca.m4 serial 12 dnl Copyright (C) 2002-2004, 2006-2007, 2009-2011 Free Software Foundation, dnl Inc. dnl This file is free software; the Free Software Foundation @@ -42,3 +42,80 @@ AC_DEFUN([gl_FUNC_ALLOCA], # 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([2.69], [] ,[ + +# This is taken from the following Autoconf patch: +# http://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=6cd9f12520b0d6f76d3230d7565feba1ecf29497 + +# _AC_LIBOBJ_ALLOCA +# ----------------- +# Set up the LIBOBJ replacement of `alloca'. Well, not exactly +# AC_LIBOBJ since we actually set the output variable `ALLOCA'. +# Nevertheless, for Automake, AC_LIBSOURCES it. +m4_define([_AC_LIBOBJ_ALLOCA], +[# The SVR3 libPW and SVR4 libucb both contain incompatible functions +# that cause trouble. Some versions do not even contain alloca or +# contain a buggy version. If you still want to use their alloca, +# use ar to extract alloca.o from them instead of compiling alloca.c. +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( +[AC_INCLUDES_DEFAULT +int +find_stack_direction (int *addr, int depth) +{ + int dir, dummy = 0; + if (! addr) + addr = &dummy; + *addr = addr < &dummy ? 1 : addr == &dummy ? 0 : -1; + dir = depth ? find_stack_direction (addr, depth - 1) : 0; + return dir + dummy; +} + +int +main (int argc, char **argv) +{ + return find_stack_direction (0, argc + !argv + 20) < 0; +}])], + [ac_cv_c_stack_direction=1], + [ac_cv_c_stack_direction=-1], + [ac_cv_c_stack_direction=0])]) +AH_VERBATIM([STACK_DIRECTION], +[/* If using the C implementation of alloca, define if you know the + direction of stack growth for your system; otherwise it will be + automatically deduced at runtime. + 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 +AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction) +])# _AC_LIBOBJ_ALLOCA +]) |