diff options
Diffstat (limited to 'gl/m4/alloca.m4')
| -rw-r--r-- | gl/m4/alloca.m4 | 86 |
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 @@ -# alloca.m4 serial 9 -dnl Copyright (C) 2002-2004, 2006-2007, 2009-2010 Free Software Foundation, +# alloca.m4 serial 14 +dnl Copyright (C) 2002-2004, 2006-2007, 2009-2013 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, @@ -7,10 +7,6 @@ dnl with or without modifications, as long as this notice is preserved. AC_DEFUN([gl_FUNC_ALLOCA], [ - dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57. - AC_REQUIRE([AC_PROG_CPP]) - AC_REQUIRE([AC_PROG_EGREP]) - AC_REQUIRE([AC_FUNC_ALLOCA]) if test $ac_cv_func_alloca_works = no; then gl_PREREQ_ALLOCA @@ -40,8 +36,86 @@ AC_DEFUN([gl_FUNC_ALLOCA], ALLOCA_H=alloca.h fi AC_SUBST([ALLOCA_H]) + AM_CONDITIONAL([GL_GENERATE_ALLOCA_H], [test -n "$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([2.69], [] ,[ + +# 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 +]) |