New compilation errors building Cygwin DLL

New compilation errors building Cygwin DLL

[Mark Geisert]

I'm getting the following two errors building after a recent 'git pull'...

/oss/src/winsup/cygwin/fhandler_socket_unix.cc: In member function 
'virtual int fhandler_socket_unix::ioctl(unsigned int, void*)':
/oss/src/winsup/cygwin/fhandler_socket_unix.cc:589:10: error: 'ret' may be 
used uninitialized in this function [-Werror=maybe-uninitialized]
    return ret;
           ^~~
/oss/src/winsup/cygwin/fhandler_socket_unix.cc: In member function 
'virtual int fhandler_socket_unix::fcntl(int, intptr_t)':
/oss/src/winsup/cygwin/fhandler_socket_unix.cc:607:10: error: 'ret' may be 
used uninitialized in this function [-Werror=maybe-uninitialized]
    return ret;
           ^~~

I'd submit a patch but I'm unsure whether ret needs initialization to 0 or 
to -1 (with appropriate set_errno(EBLAH)).

Thanks,

..mark

Re: New compilation errors building Cygwin DLL

[Corinna Vinschen]

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On Feb 24 16:28, Mark Geisert wrote:
> I'm getting the following two errors building after a recent 'git pull'...
> 
> /oss/src/winsup/cygwin/fhandler_socket_unix.cc: In member function 'virtual
> int fhandler_socket_unix::ioctl(unsigned int, void*)':
> /oss/src/winsup/cygwin/fhandler_socket_unix.cc:589:10: error: 'ret' may be
> used uninitialized in this function [-Werror=maybe-uninitialized]
>    return ret;
>           ^~~
> /oss/src/winsup/cygwin/fhandler_socket_unix.cc: In member function 'virtual
> int fhandler_socket_unix::fcntl(int, intptr_t)':
> /oss/src/winsup/cygwin/fhandler_socket_unix.cc:607:10: error: 'ret' may be
> used uninitialized in this function [-Werror=maybe-uninitialized]
>    return ret;
>           ^~~
> 
> I'd submit a patch but I'm unsure whether ret needs initialization to 0 or
> to -1 (with appropriate set_errno(EBLAH)).

This is nothing to worry about.  It's WIP and the functions have just
been copied from fhandler_socket_local to fhandler_socket_unix and then
stripped down to just keep the stuff required to keep in mind for the
new implemantation.  Just ignore any errors from fhandler_socket_unix
for the time being.


Corinna

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

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Re: New compilation errors building Cygwin DLL

[Mark A. Engel]

Hi, I have been trying to build the cross unix/linux compiler and using 
the following document;
    http://preshing.com/20141119/how-to-build-a-gcc-cross-compiler/
and all is good until I get to step 6 (of the document and I get this 
error.  I'm not sure where I need to go to fix this error.  I have put in

#ifndef RTLD_PRIVATE_ERRNO
#define RTLD_PRIVATE_ERRNO 1
#endif

in the sysdep.h and dl-sysdep.h header files which cleared some of the 
undefined rtld_errno but not all.  Please help and steer me in the right 
direction.

    make[2]: Entering directory '/home/MarkEngel/downloads/glibc-2.26/elf'
    make -f /home/MarkEngel/downloads/build-glibc/elf/librtld.mk -f
    rtld-Rules
    make[3]: Entering directory '/home/MarkEngel/downloads/glibc-2.26/elf'
    make subdir=dirent -C ../dirent ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-closedir.os
    rtld-readdir.os rtld-rewinddir.os rtld-getdents64.os rtld-fdopendir.os'
    make subdir=elf -C ../elf ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-dl-addr-obj.os'
    make subdir=gmon -C ../gmon ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-profil.os
    rtld-prof-freq.os'
    make subdir=io -C ../io ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-xstat.os
    rtld-fxstat.os rtld-lxstat.os rtld-open64.os rtld-read.os
    rtld-write.os rtld-lseek64.os rtld-access.os rtld-fcntl.os
    rtld-close.os'
    make[4]: Entering directory '/home/MarkEngel/downloads/glibc-2.26/elf'
    make subdir=misc -C ../misc ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-mmap64.os
    rtld-munmap.os rtld-mprotect.os'
    make subdir=nptl -C ../nptl ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-libc-lowlevellock.os
    rtld-libc-cancellation.os rtld-libc_multiple_threads.os rtld-forward.os'
    make subdir=posix -C ../posix ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-uname.os rtld-_exit.os
    rtld-getpid.os rtld-environ.os'
    make[4]: Leaving directory '/home/MarkEngel/downloads/glibc-2.26/elf'
    make subdir=setjmp -C ../setjmp ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-setjmp.os
    rtld-__longjmp.os'
    make subdir=signal -C ../signal ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-sigaction.os'
    make subdir=stdlib -C ../stdlib ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-exit.os
    rtld-cxa_atexit.os rtld-cxa_thread_atexit_impl.os'
    make subdir=string -C ../string ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-strchr.os
    rtld-strcmp.os rtld-strcspn.os rtld-strdup.os rtld-strlen.os
    rtld-strnlen.os rtld-memchr.os rtld-memcmp.os rtld-memmove.os
    rtld-memset.os rtld-mempcpy.os rtld-stpcpy.os rtld-memcpy.os
    rtld-rawmemchr.os rtld-strchrnul.os rtld-memcpy_generic.os
    rtld-memcpy_thunderx.os'
    make subdir=time -C ../time ..=../
    objdir=/home/MarkEngel/downloads/build-glibc -f Makefile -f
    ../elf/rtld-Rules rtld-all rtld-modules='rtld-setitimer.os'
    make[4]: Entering directory '/home/MarkEngel/downloads/glibc-2.26/nptl'
    make[4]: Leaving directory '/home/MarkEngel/downloads/glibc-2.26/nptl'
    make[3]: Leaving directory '/home/MarkEngel/downloads/glibc-2.26/elf'
    aarch64-linux-gcc   -nostdlib -nostartfiles -shared -o
    /home/MarkEngel/downloads/build-glibc/elf/ld.so.new \
               -Wl,-z,combreloc -Wl,-z,relro -Wl,--hash-style=both
    -Wl,-z,defs       \
               /home/MarkEngel/downloads/build-glibc/elf/librtld.os
    -Wl,--version-script=/home/MarkEngel/downloads/build-glibc/ld.map \
    -Wl,-soname=ld-linux-aarch64.so.1                     \
               -Wl,-defsym=_begin=0
    /home/MarkEngel/downloads/build-glibc/elf/librtld.os: In function
    `_dl_map_object_from_fd':
    /home/MarkEngel/downloads/glibc-2.26/elf/dl-load.c:890: undefined
    reference to `rtld_errno'
    /home/MarkEngel/downloads/glibc-2.26/elf/dl-load.c:890: undefined
    reference to `rtld_errno'
    /home/MarkEngel/downloads/glibc-2.26/elf/dl-load.c:890: undefined
    reference to `rtld_errno'
    /home/MarkEngel/downloads/glibc-2.26/elf/dl-load.c:890: undefined
    reference to `rtld_errno'
    /home/MarkEngel/downloads/glibc-2.26/elf/dl-load.c:890: undefined
    reference to `rtld_errno'
    /home/MarkEngel/downloads/build-glibc/elf/librtld.os:/home/MarkEngel/downloads/glibc-2.26/elf/dl-load.c:890:
    more undefined references to `rtld_errno' follow
    /home/MarkEngel/downloads/build-glibc/elf/librtld.os: In function
    `_dl_sysdep_start':
    /home/MarkEngel/downloads/glibc-2.26/elf/../elf/dl-sysdep.c:251:
    undefined reference to `__libc_check_standard_fds'
    /home/MarkEngel/downloads/build-glibc/elf/librtld.os: In function
    `__brk':
    /home/MarkEngel/downloads/glibc-2.26/elf/../sysdeps/unix/sysv/linux/generic/brk.c:39:
    undefined reference to `rtld_errno'
    /home/MarkEngel/downloads/glibc-2.26/elf/../sysdeps/unix/sysv/linux/generic/brk.c:39:
    undefined reference to `rtld_errno'
    /home/MarkEngel/downloads/build-glibc/elf/librtld.os: In function
    `__sbrk':
    /home/MarkEngel/downloads/glibc-2.26/elf/../misc/sbrk.c:54:
    undefined reference to `rtld_errno'
    /home/MarkEngel/downloads/glibc-2.26/elf/../misc/sbrk.c:54:
    undefined reference to `rtld_errno'
    /home/MarkEngel/downloads/build-glibc/elf/librtld.os: In function
    `__getcwd':
    /home/MarkEngel/downloads/glibc-2.26/elf/../sysdeps/unix/sysv/linux/getcwd.c:129:
    undefined reference to `rtld_errno'
    /home/MarkEngel/downloads/build-glibc/elf/librtld.os:/home/MarkEngel/downloads/glibc-2.26/elf/../sysdeps/unix/sysv/linux/getcwd.c:129:
    more undefined references to `rtld_errno' follow
    /opt/cross/lib/gcc/aarch64-linux/7.2.0/../../../../aarch64-linux/bin/ld:
    /home/MarkEngel/downloads/build-glibc/elf/ld.so.new: hidden symbol
    `__libc_check_standard_fds' isn't defined
    /opt/cross/lib/gcc/aarch64-linux/7.2.0/../../../../aarch64-linux/bin/ld:
    final link failed: Bad value
    collect2: error: ld returned 1 exit status
    make[2]: *** [Makefile:464:
    /home/MarkEngel/downloads/build-glibc/elf/ld.so] Error 1
    make[2]: Leaving directory '/home/MarkEngel/downloads/glibc-2.26/elf'
    make[1]: *** [Makefile:215: elf/subdir_lib] Error 2
    make[1]: Leaving directory '/home/MarkEngel/downloads/glibc-2.26'
    make: *** [Makefile:9: all] Error 2

    Mark Engel@Mark-Development ~/downloads/build-glibc



-- 
Mark Engel
Software Engineer
630 960-5300
mark.engel@comcast.net

Re: New compilation errors building Cygwin DLL

[Mark Geisert]

Hi Mark,

On Sun, 25 Feb 2018, Mark A. Engel wrote:
> Hi, I have been trying to build the cross unix/linux compiler and using the 
> following document;
>   http://preshing.com/20141119/how-to-build-a-gcc-cross-compiler/
> and all is good until I get to step 6 (of the document and I get this error. 
> I'm not sure where I need to go to fix this error.  I have put in
>
> #ifndef RTLD_PRIVATE_ERRNO
> #define RTLD_PRIVATE_ERRNO 1
> #endif
>
> in the sysdep.h and dl-sysdep.h header files which cleared some of the 
> undefined rtld_errno but not all.  Please help and steer me in the right 
> direction.
>
>   make[2]: Entering directory '/home/MarkEngel/downloads/glibc-2.26/elf'
>   make -f /home/MarkEngel/downloads/build-glibc/elf/librtld.mk -f
>   rtld-Rules
[...]

What you're doing doesn't seem to have anything to do with building the 
Cygwin DLL itself, so this is the wrong mailing list.  The web page you 
indicated has a comment form at its end.  You might use that to reach the 
page's author or perhaps one of the responders already quoted who has used 
Cygwin to build the cross-compiler.
Good luck,

..mark