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>

Description:
isnand() function: test for NaN.

Files:
lib/isnand.c
lib/isnan.c
lib/float+.h
m4/exponentd.m4
m4/isnand.m4

Depends-on:
math
fpieee
memcmp

configure.ac:
gl_FUNC_ISNAND
m4_ifdef([gl_ISNAN], [
  AC_REQUIRE([gl_ISNAN])
])
if test $HAVE_ISNAND = 0 || test $REPLACE_ISNAN = 1; then
  AC_LIBOBJ([isnand])
  gl_PREREQ_ISNAND
fi
gl_MATH_MODULE_INDICATOR([isnand])

Makefile.am:

Include:
<math.h>

Link:
$(ISNAND_LIBM)

License:
LGPL

Maintainer:
Bruno Haible