Re: [PATCH] libstdc++-v3: Check for TLS support on mingw

[Jonathan Wakely via Gcc-patches]

On Wed, 1 Sept 2021 at 10:52, Jonathan Wakely  wrote:
>
> On Wed, 1 Sept 2021 at 02:44, Jonathan Yong <10wa...@gmail.com> wrote:
> >
> > On 8/31/21 9:02 AM, Jonathan Wakely wrote:
> > > It looks like my questions about this patch never got an answer, and
> > > it never got applied.
> > >
> > > Could somebody say whether TLS is enabled for native *-*-mingw*
> > > builds? If it is, then we definitely need to add GCC_CHECK_TLS to the
> > > cross-compiler config too.
> > >
> > > For a linux-hosted x86_64-w64-mingw32 cross compiler I see TLS is not 
> > > enabled:
> > >
> > > /* Define to 1 if the target supports thread-local storage. */
> > > /* #undef _GLIBCXX_HAVE_TLS */
> > >
> > >
> > >
> > >
> > > On Mon, 19 Feb 2018 at 08:59, Hugo Beauzée-Luyssen  
> > > wrote:
> > >>
> > >> libstdc++-v3: Check for TLS support on mingw
> > >>
> > >> 2018-02-16  Hugo Beauzée-Luyssen  
> > >>
> > >>  * crossconfig.m4: Check for TLS support on mignw
> > >>  * configure: regenerate
> > >>
> > >> Index: libstdc++-v3/crossconfig.m4
> > >> ===
> > >> --- libstdc++-v3/crossconfig.m4 (revision 257730)
> > >> +++ libstdc++-v3/crossconfig.m4 (working copy)
> > >> @@ -197,6 +197,7 @@ case "${host}" in
> > >>   GLIBCXX_CHECK_LINKER_FEATURES
> > >>   GLIBCXX_CHECK_MATH_SUPPORT
> > >>   GLIBCXX_CHECK_STDLIB_SUPPORT
> > >> +GCC_CHECK_TLS
> > >>   ;;
> > >> *-netbsd*)
> > >>   SECTION_FLAGS='-ffunction-sections -fdata-sections'
> >
> > According to MSYS2 native from
> > https://mirror.msys2.org/mingw/ucrt64/mingw-w64-ucrt-x86_64-gcc-10.3.0-5-any.pkg.tar.zst:
> >
> > x86_64-w64-mingw32/bits/c++config.h:#define _GLIBCXX_HAVE_TLS 1
> >
> > So yes.
>
> Thanks! I'll test the patch on a cross-compiler and apply it soon then.
>
> (Thanks also to LH for the answer)

I've pushed this to trunk now. Thanks for the patch, Hugo. Sorry it
took so long to process.

Re: [PATCH] libstdc++-v3: Check for TLS support on mingw

[Jonathan Wakely via Gcc-patches]

On Wed, 1 Sept 2021 at 02:44, Jonathan Yong <10wa...@gmail.com> wrote:
>
> On 8/31/21 9:02 AM, Jonathan Wakely wrote:
> > It looks like my questions about this patch never got an answer, and
> > it never got applied.
> >
> > Could somebody say whether TLS is enabled for native *-*-mingw*
> > builds? If it is, then we definitely need to add GCC_CHECK_TLS to the
> > cross-compiler config too.
> >
> > For a linux-hosted x86_64-w64-mingw32 cross compiler I see TLS is not 
> > enabled:
> >
> > /* Define to 1 if the target supports thread-local storage. */
> > /* #undef _GLIBCXX_HAVE_TLS */
> >
> >
> >
> >
> > On Mon, 19 Feb 2018 at 08:59, Hugo Beauzée-Luyssen  wrote:
> >>
> >> libstdc++-v3: Check for TLS support on mingw
> >>
> >> 2018-02-16  Hugo Beauzée-Luyssen  
> >>
> >>  * crossconfig.m4: Check for TLS support on mignw
> >>  * configure: regenerate
> >>
> >> Index: libstdc++-v3/crossconfig.m4
> >> ===
> >> --- libstdc++-v3/crossconfig.m4 (revision 257730)
> >> +++ libstdc++-v3/crossconfig.m4 (working copy)
> >> @@ -197,6 +197,7 @@ case "${host}" in
> >>   GLIBCXX_CHECK_LINKER_FEATURES
> >>   GLIBCXX_CHECK_MATH_SUPPORT
> >>   GLIBCXX_CHECK_STDLIB_SUPPORT
> >> +GCC_CHECK_TLS
> >>   ;;
> >> *-netbsd*)
> >>   SECTION_FLAGS='-ffunction-sections -fdata-sections'
>
> According to MSYS2 native from
> https://mirror.msys2.org/mingw/ucrt64/mingw-w64-ucrt-x86_64-gcc-10.3.0-5-any.pkg.tar.zst:
>
> x86_64-w64-mingw32/bits/c++config.h:#define _GLIBCXX_HAVE_TLS 1
>
> So yes.

Thanks! I'll test the patch on a cross-compiler and apply it soon then.

(Thanks also to LH for the answer)

Re: [PATCH] libstdc++-v3: Check for TLS support on mingw

[Jonathan Yong via Gcc-patches]

On 8/31/21 9:02 AM, Jonathan Wakely wrote:

It looks like my questions about this patch never got an answer, and
it never got applied.

Could somebody say whether TLS is enabled for native *-*-mingw*
builds? If it is, then we definitely need to add GCC_CHECK_TLS to the
cross-compiler config too.

For a linux-hosted x86_64-w64-mingw32 cross compiler I see TLS is not enabled:

/* Define to 1 if the target supports thread-local storage. */
/* #undef _GLIBCXX_HAVE_TLS */




On Mon, 19 Feb 2018 at 08:59, Hugo Beauzée-Luyssen  wrote:


libstdc++-v3: Check for TLS support on mingw

2018-02-16  Hugo Beauzée-Luyssen  

 * crossconfig.m4: Check for TLS support on mignw
 * configure: regenerate

Index: libstdc++-v3/crossconfig.m4
===
--- libstdc++-v3/crossconfig.m4 (revision 257730)
+++ libstdc++-v3/crossconfig.m4 (working copy)
@@ -197,6 +197,7 @@ case "${host}" in
  GLIBCXX_CHECK_LINKER_FEATURES
  GLIBCXX_CHECK_MATH_SUPPORT
  GLIBCXX_CHECK_STDLIB_SUPPORT
+GCC_CHECK_TLS
  ;;
*-netbsd*)
  SECTION_FLAGS='-ffunction-sections -fdata-sections'


According to MSYS2 native from 
https://mirror.msys2.org/mingw/ucrt64/mingw-w64-ucrt-x86_64-gcc-10.3.0-5-any.pkg.tar.zst:


x86_64-w64-mingw32/bits/c++config.h:#define _GLIBCXX_HAVE_TLS 1

So yes.


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Re:Re: [PATCH] libstdc++-v3: Check for TLS support on mingw

[lhmouse via Gcc-patches]

在 2021-08-31 17:02, Jonathan Wakely 写道:
> It looks like my questions about this patch never got an answer, and
> it never got applied.
> 
> Could somebody say whether TLS is enabled for native *-*-mingw*
> builds? If it is, then we definitely need to add GCC_CHECK_TLS to the
> cross-compiler config too.
> 
> For a linux-hosted x86_64-w64-mingw32 cross compiler I see TLS is not enabled:
> 
> /* Define to 1 if the target supports thread-local storage. */
> /* #undef _GLIBCXX_HAVE_TLS */
> 

I have been disabling it with `--disable-tls` for years, but... I couldn't 
remember why. Thread-local storage is implemented with emutls, no matter with 
or without this option.

Does 'thread-local storage' mean to access thread-local objects via the FS or 
GS register on x86? If so, then it is definitely not supported yet.


-- 
Best regards,
LIU Hao

Re: [PATCH] libstdc++-v3: Check for TLS support on mingw

[Jonathan Wakely via Gcc-patches]

It looks like my questions about this patch never got an answer, and
it never got applied.

Could somebody say whether TLS is enabled for native *-*-mingw*
builds? If it is, then we definitely need to add GCC_CHECK_TLS to the
cross-compiler config too.

For a linux-hosted x86_64-w64-mingw32 cross compiler I see TLS is not enabled:

/* Define to 1 if the target supports thread-local storage. */
/* #undef _GLIBCXX_HAVE_TLS */




On Mon, 19 Feb 2018 at 08:59, Hugo Beauzée-Luyssen  wrote:
>
> libstdc++-v3: Check for TLS support on mingw
>
> 2018-02-16  Hugo Beauzée-Luyssen  
>
> * crossconfig.m4: Check for TLS support on mignw
> * configure: regenerate
>
> Index: libstdc++-v3/crossconfig.m4
> ===
> --- libstdc++-v3/crossconfig.m4 (revision 257730)
> +++ libstdc++-v3/crossconfig.m4 (working copy)
> @@ -197,6 +197,7 @@ case "${host}" in
>  GLIBCXX_CHECK_LINKER_FEATURES
>  GLIBCXX_CHECK_MATH_SUPPORT
>  GLIBCXX_CHECK_STDLIB_SUPPORT
> +GCC_CHECK_TLS
>  ;;
>*-netbsd*)
>  SECTION_FLAGS='-ffunction-sections -fdata-sections'

Re: [PATCH] libstdc++-v3: Check for TLS support on mingw

[Jonathan Wakely]

Apologies if you get this mail multiple times, I'm having some trouble
sending mail to @gcc.gnu.org lists.



On 19/02/18 09:59 +0100, Hugo Beauzée-Luyssen wrote:
> libstdc++-v3: Check for TLS support on mingw
>
> 2018-02-16  Hugo Beauzée-Luyssen  
>
>* crossconfig.m4: Check for TLS support on mignw

Typo "minwg"

>* configure: regenerate
>
> Index: libstdc++-v3/crossconfig.m4
> ===
> --- libstdc++-v3/crossconfig.m4 (revision 257730)
> +++ libstdc++-v3/crossconfig.m4 (working copy)
> @@ -197,6 +197,7 @@ case "${host}" in
> GLIBCXX_CHECK_LINKER_FEATURES
> GLIBCXX_CHECK_MATH_SUPPORT
> GLIBCXX_CHECK_STDLIB_SUPPORT
> +GCC_CHECK_TLS
> ;;
>   *-netbsd*)
> SECTION_FLAGS='-ffunction-sections -fdata-sections'

Hi, thanks for the patch. I don't think we can apply it now, as the
GCC trunk is only open for regression fixes until GCC 8 is released.

How was this tested? Will it work for all versions of mingw that we
support? Is TLS enabled for native builds? (If so we definitely need
this, because otherwise mingw cross-compilers are not ABI compatibnle
with native ones).

[PATCH] libstdc++-v3: Check for TLS support on mingw

[Hugo Beauzée-Luyssen]

libstdc++-v3: Check for TLS support on mingw

2018-02-16  Hugo Beauzée-Luyssen  

* crossconfig.m4: Check for TLS support on mignw
* configure: regenerate

Index: libstdc++-v3/crossconfig.m4
===
--- libstdc++-v3/crossconfig.m4 (revision 257730)
+++ libstdc++-v3/crossconfig.m4 (working copy)
@@ -197,6 +197,7 @@ case "${host}" in
 GLIBCXX_CHECK_LINKER_FEATURES
 GLIBCXX_CHECK_MATH_SUPPORT
 GLIBCXX_CHECK_STDLIB_SUPPORT
+GCC_CHECK_TLS
 ;;
   *-netbsd*)
 SECTION_FLAGS='-ffunction-sections -fdata-sections'