Re: Destructors not called for c++11 thread_local objects

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

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On Aug  1 13:41, Larry Hall (Cygwin) wrote:
> On 08/01/2014 01:32 PM, Ryan Johnson wrote:
> >Hi all,
> >
> >(Please CC me in replies, I'm not subscribed to the list)
> >
> >Question: is this a Cygwin bug, gcc bug, or somebody else's bug entirely?
> >
> >The following STC shows the problem:
> >
> >$ cat bug.cpp
> >#include <cstdio>
> >static thread_local struct X {
> >     int x;
> >     X() { puts("hi"); }
> >     ~X() { puts("bye!"); }
> >} x;
> >int main() { x.x = 0; }
> >
> >$ g++ -std=gnu++11 -Wall -g bug.cpp && ./a
> >hi
> >
> >A quick inspection of the assembly code shows no call to __cxa_thread_atexit
> >in __tls_init, where the same code compiled on linux, with the same version
> >of gcc, has it right. This is odd, because the function does seem to be
> >available in cygwin's libstdc++:
> >
> >$ nm /usr/lib/gcc/x86_64-pc-cygwin/4.8.3/libstdc++.a | grep thread_atexit
> >0000000000000000 d .data$_ZZ19__cxa_thread_atexitE4once
> >0000000000000000 p .pdata$__cxa_thread_atexit
> >0000000000000000 t .text$__cxa_thread_atexit
> >0000000000000000 r .xdata$__cxa_thread_atexit
> >0000000000000000 T __cxa_thread_atexit
> >0000000000000000 d _ZZ19__cxa_thread_atexitE4once
> >[...]
> 
> Well it's not a general gcc problem because the same code on Linux with
> version 4.8.3 works for me.

It seems thread_local storage needs to be implemented in GCC for the
target, and it isn't.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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