regex: avoid glibc deadlock during configure glibc has a known bug where certain corruptions of the heap can cause malloc to default to printing a debug message that includes a backtrace, but the act of getting the backtrace uses dlopen which in turn calls into malloc, causing a recursive lock ending in deadlock. Thus, when configure is probing for a known glibc heap corruption bug, the overall configure would hang. The solution suggested by glibc developers is to force malloc to quit printing debug messages, which avoids recursive malloc. * m4/regex.m4 (gl_REGEX): Avoid recursive malloc deadlock when glibc bug 15078 in turn triggers bug 16159. Reported by Michal Privoznik. Signed-off-by: Eric Blake <eblake@redhat.com>

# logf-ieee.m4 serial 1
dnl Copyright (C) 2012-2013 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

dnl This macro is in a separate file (not in remainder.m4 and not inlined in the
dnl module description), so that gl_FUNC_LOGF can test whether 'aclocal' has
dnl found uses of this macro.

AC_DEFUN([gl_FUNC_LOGF_IEEE],
[
  m4_divert_text([INIT_PREPARE], [gl_logf_required=ieee])
  AC_REQUIRE([gl_FUNC_LOGF])
])