llvm / clang and thread_local storage problems

[Jack Howarth]

On Sun, Oct 9, 2016 at 3:20 PM, Jeremy Huddleston Sequoia
<jeremyhu at apple.com> wrote:
>
>> On Oct 9, 2016, at 09:47, Jack Howarth <howarth.at.macports at gmail.com> wrote:
>>
>> On Sun, Oct 9, 2016 at 3:53 AM, Jeremy Huddleston Sequoia
>> <jeremyhu at apple.com> wrote:
>>> thread_local support was added in OS X 10.9 (along with __cxa_thread_atexit being added to Libc as part of that support).  As long as your minimum deployment target is 10.9, you should be fine.  The issue is that you're on 10.6, so you don't have __cxa_thread_atexit.
>>>
>>> There is active conversation right now about adding a fallback implementation of __cxa_thread_atexit directly into libcxxabi.  See https://reviews.llvm.org/D21803 as that might be quite useful for your needs.  If so, provide a patch to libcxxabi that incorporates it, and I'll get it in.
>>
>> On the topic of thread local support, the failures in the guile 2.0.x
>> test suite should be looked at...
>>
>> https://trac.macports.org/ticket/52556
>>
>> to determine if Apple's thread-local-storage implementation is buggy
>> as upstream guile claims.
>
> Radar?

Jeremy,
      I finally puzzled out how to run the offending test case in
guile by itself. This can be done using the current MacPorts guile
2.0.13 using...


1) Installl MacPorts and then execute "sudo port -d install guile" in
a Terminal window to install the dependencies required for guile as
well as guile
2) In a terminal window, execute 'sudo port -d build guile' to rebuild
guile retaining the build directory.
3) change directory into the MacPorts build directory for guile
2.0.13. In my case this was with....

cd /opt/local/var/macports/build/_Users_howarth_ports_lang_guile/guile/work/guile-2.0.13/test-suite

5) change to sudo because MacPorts work directories are owned by root

sudo csh

4) set the required environmental variables for the guile-test test
harness script...

setenv GUILE_LOAD_PATH
/opt/local/var/macports/build/_Users_howarth_ports_lang_guile/guile/work/guile-2.0.13/test-suite
setenv TEST_SUITE_DIR
/opt/local/var/macports/build/_Users_howarth_ports_lang_guile/guile/work/guile-2.0.13/test-suite/tests

5) finally run the failing test case under the installed MacPort's guile...

/opt/local/bin/guile  -e main -s guile-test srfi-18.test

Running srfi-18.test
FAIL: srfi-18.test: thread-terminate!: termination destroys non-started thread
FAIL: srfi-18.test: thread-terminate!: termination destroys started thread

Totals for this test run:
passes:                 59
failures:               2
unexpected passes:      0
expected failures:      0
unresolved test cases:  0
untested test cases:    0
unsupported test cases: 0
errors:                 0

I've added those details to radar://28688091 "guile 2.0.12 exposes
potential thread-local-storage bug on Mac OS X".
             Jack
ps The problem was that the comments in the guile-test test harness,
for running the tests individually, mentioned the need to set
TEST_SUITE_DIR but failed to discuss the need to set GUILE_LOAD_PATH
as well.


>