Brian Inglis wrote:
> > Can you also try to build it through
> >
> > gl_cv_have_weak=no ../configure -C && make && make check
> >
> > in a different subdirectory?
> >
> > Please send the config.log, config.cache, config.status, and
> > gltests/test-suite.log for each run.
>
> Done and attached
Thanks! Indeed, gl_cv_have_weak=no appears to make the essential difference.
Therefore, I'm applying this fix.
2021-09-17 Bruno Haible <br...@clisp.org>
threadlib: Avoid crashes in thread-related functions on Cygwin 3.2.0.
Reported by Brian Inglis via Akim Demaille in
<https://lists.gnu.org/archive/html/bug-gnulib/2021-09/msg00063.html>.
* m4/threadlib.m4 (gl_WEAK_SYMBOLS): Force a "guessing no" result on
Cygwin.
diff -w --git a/m4/threadlib.m4 b/m4/threadlib.m4
index 37b797c18..6b43bbdfa 100644
--- a/m4/threadlib.m4
+++ b/m4/threadlib.m4
@@ -1,4 +1,4 @@
-# threadlib.m4 serial 31
+# threadlib.m4 serial 32
dnl Copyright (C) 2005-2021 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -84,7 +84,15 @@ AC_DEFUN([gl_WEAK_SYMBOLS],
AC_REQUIRE([AC_CANONICAL_HOST])
AC_CACHE_CHECK([whether imported symbols can be declared weak],
[gl_cv_have_weak],
- [gl_cv_have_weak=no
+ [case "$host_os" in
+ cygwin*)
+ dnl On Cygwin 3.2.0 with gcc 10.2, the test below would succeed, but
+ dnl programs that use pthread_in_use() with weak symbol references
+ dnl crash miserably at runtime.
+ gl_cv_have_weak="guessing no"
+ ;;
+ *)
+ gl_cv_have_weak=no
dnl First, test whether the compiler accepts it syntactically.
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
@@ -116,6 +124,8 @@ int main ()
[gl_cv_have_weak="guessing no"])
])
fi
+ ;;
+ esac
dnl But when linking statically, weak symbols don't work.
case " $LDFLAGS " in
*" -static "*) gl_cv_have_weak=no ;;
