[Bug c/99913] New: GCC11 fails to build for MinGW-w64 for Windows 32-bit

[Bug c/99913] New: GCC11 fails to build for MinGW-w64 for Windows 32-bit

[brechtsanders at users dot sourceforge.net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99913

            Bug ID: 99913
           Summary: GCC11 fails to build for MinGW-w64 for Windows 32-bit
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: brechtsanders at users dot sourceforge.net
  Target Milestone: ---

Created attachment 50509
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50509&action=edit
i686-w64-mingw32/libgomp/config.log

When building GCC 11 (including latest snapshot 20210404) against MinGW-w64 for
Windows 32-bit using an existing MinGW-w64 Windows 32-bit gcc configure stops
with the following error:

configure: error: unsupported system, cannot find sizeof (omp_lock_t)

This error is logged to file i686-w64-mingw32/libgomp/config.log which I have
attached.

At first glance it seems like it's not finding symbols that require
-lwinpthread

Note that there are no issues building GCC 11 against MinGW-w64 for Windows
64-bit.

[Bug target/99913] GCC11 fails to build for MinGW-w64 for Windows 32-bit

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99913

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I Noticed:
--enable-threads=posix 
and the error message is:

D:\prog\winlibs32_stage\mingw32\i686-w64-mingw32\bin\ld.exe:
R:/winlibs32_stage/gcc-11-20210404/build_mingw/gcc/libgcc_eh.a(unwind-dw2.o):
in function `_gthread_once':
R:\winlibs32_stage\gcc-11-20210404\build_mingw\i686-w64-mingw32\libgcc/./gthr-default.h:700:
undefined reference to `pthread_once'
....
More undefined references to pthread_*

Either pthreads-win32 is not installed correctly or is not being linked
correctly here.

[Bug target/99913] GCC11 fails to build for MinGW-w64 for Windows 32-bit

[brechtsanders at users dot sourceforge.net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99913

--- Comment #2 from Brecht Sanders <brechtsanders at users dot sourceforge.net> ---
By the time I get to that error the build process already generated these
files:
- mingw-w64/mingw/lib/libwinpthread.a
- mingw-w64/mingw/lib/libwinpthread.dll.a
- mingw-w64/mingw/lib/libwinpthread.la
However I couldn't find a matching DLL, which I assume should be here:
- mingw-w64/mingw/bin/libwinpthread-1.dll

[Bug target/99913] GCC11 fails to build for MinGW-w64 for Windows 32-bit

[brechtsanders at users dot sourceforge.net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99913

--- Comment #3 from Brecht Sanders <brechtsanders at users dot sourceforge.net> ---
Just to clarify: libwinpthread is built as part of the GCC build against
MinGW-w64.
MinGW-w64 also already has a libwinpthread (including libwinpthread-1.dll which
can be found in the PATH).

[Bug target/99913] GCC11 fails to build for MinGW-w64 for Windows 32-bit

[lh_mouse at 126 dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99913

LIU Hao <lh_mouse at 126 dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |lh_mouse at 126 dot com

--- Comment #4 from LIU Hao <lh_mouse at 126 dot com> ---
Is there still such an error for you?

It looks to me that this linker command line did not contain `-pthread` unlike
the ones above. Maybe the configure script is worth looking at.

```
configure:16911: /R/winlibs32_stage/gcc-11-20210404/build_mingw/./gcc/xgcc
-B/R/winlibs32_stage/gcc-11-20210404/build_mingw/./gcc/
-L/R/winlibs32_stage/inst_gcc-11-20210404/share/gcc/i686-w64-mingw32/lib
-L/R/winlibs32_stage/inst_gcc-11-20210404/share/gcc/mingw/lib -isystem
/R/winlibs32_stage/inst_gcc-11-20210404/share/gcc/i686-w64-mingw32/include
-isystem /R/winlibs32_stage/inst_gcc-11-20210404/share/gcc/mingw/include
-B/R/winlibs32_stage/inst_gcc-11-20210404/share/gcc/i686-w64-mingw32/bin/
-B/R/winlibs32_stage/inst_gcc-11-20210404/share/gcc/i686-w64-mingw32/lib/
-isystem
/R/winlibs32_stage/inst_gcc-11-20210404/share/gcc/i686-w64-mingw32/include
-isystem
/R/winlibs32_stage/inst_gcc-11-20210404/share/gcc/i686-w64-mingw32/sys-include
--sysroot=/R/winlibs32_stage/gcc-11-20210404/build_mingw/mingw-w64   -o
conftest.exe -O0 -include confdefs.h -include
../../../libgomp/config/posix/omp-lock.h  -s conftest.c -ldl  >&5
D:\prog\winlibs32_stage\mingw32\i686-w64-mingw32\bin\ld.exe:
R:/winlibs32_stage/gcc-11-20210404/build_mingw/gcc/libgcc_eh.a(unwind-dw2.o):
in function `_gthread_once':
R:\winlibs32_stage\gcc-11-20210404\build_mingw\i686-w64-mingw32\libgcc/./gthr-default.h:700:
undefined reference to `pthread_once'
```

[Bug target/99913] GCC11 fails to build for MinGW-w64 for Windows 32-bit

[brechtsanders at users dot sourceforge.net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99913

Brecht Sanders <brechtsanders at users dot sourceforge.net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #5 from Brecht Sanders <brechtsanders at users dot sourceforge.net> ---
I can confirm GCC 13.2.0 builds with MinGW-w64 11.0.1 without explicitly
configuring with LDFLAGS="-pthread"