Mercurial > gnulib
view m4/vararrays.m4 @ 37246:5cfb3a67238d
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>
author | Eric Blake <eblake@redhat.com> |
---|---|
date | Tue, 03 Dec 2013 10:34:13 -0700 |
parents | c741bc27922a |
children | 344018b6e5d7 |
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# Check for variable-length arrays. # serial 4 # From Paul Eggert # Copyright (C) 2001, 2009-2013 Free Software Foundation, Inc. # This file is free software; the Free Software Foundation # gives unlimited permission to copy and/or distribute it, # with or without modifications, as long as this notice is preserved. AC_DEFUN([AC_C_VARARRAYS], [ AC_CACHE_CHECK([for variable-length arrays], ac_cv_c_vararrays, [AC_COMPILE_IFELSE([AC_LANG_PROGRAM( [], [[static int x; char a[++x]; a[sizeof a - 1] = 0; return a[0];]])], ac_cv_c_vararrays=yes, ac_cv_c_vararrays=no)]) if test $ac_cv_c_vararrays = yes; then AC_DEFINE([HAVE_C_VARARRAYS], [1], [Define to 1 if C supports variable-length arrays.]) fi ])