Re: bison segv under Cygwin 64 at fatal-signal.c:318

[Brian Inglis]

On 2021-09-17 14:25, Bruno Haible wrote:

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 ;;

Respun and applied patch successfully to glm4/threadlib.m4.

Were there additional conditions required to ensure that was used?



Please see attached tars for logs and config.*.







Please see attached bison...check.log.gz.



--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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Patch would not apply as included gnulib and bison threadlib.m4 appear to be from July and August. Still did not change gnulib or bison builds to configure weak=no or check successfully. Had to configure with explicit gl_cv_have_weak=no arg to successfully configure and run tests. Patch also made no difference to bison build, but adding to CYGCONF_ARGS explicit gl_cv_have_weak=no allowed all tests to run: * D, Java, 129: Output file name: `~!..., 150: Tabulations and multibyte characters, 283-287: syncline escapes, 647: LAC: Exploratory stack, were skipped; * all but two others 672-673: Doxygen Public-Private Documentation were successful. So the diagnosis and cure were correct and worked, but the patch did not seem to make any difference?

bison-3.8.1-0-check.log.gz
Description: GNU Zip compressed data

gnulib-testdir-build.tar.xz
Description: Binary data

gnulib-testdir-weak-no.tar.xz
Description: Binary data