Re: environ: fix link error on 64-bit Cygwin
On 2/26/2018 4:28 PM, Ken Brown wrote: > On 1/31/2018 9:40 AM, Corinna Vinschen wrote: >> On Jan 31 07:52, Eric Blake wrote: >>> Forwarding from the gnulib list; is this something we should fix in >>> cygwin proper? >> >> Why does anybody remove the -Wl,--disable-auto-import flag? What for? >> The idea was to never use this flag on Cygwin and to get rid of the >> dllimport/dllexport nonsense... >> >>> On 01/31/2018 04:42 AM, Bruno Haible wrote: On 64-bit Cygwin, a libunistring build fails like this: [...] libtool: link: x86_64-pc-cygwin-gcc -g -O2 -Wl,--disable-auto-import -o .libs/test-environ.exe test-environ.o -L/usr/local/cygwin64/lib libtests.a ../lib/.libs/libunistring.dll.a -liconv libtests.a -L/usr/local/cygwin64/lib test-environ.o:test-environ.c:(.rdata$.refptr.environ[.refptr.environ]+0x0): undefined reference to `environ' collect2: error: ld returned 1 exit status This fixes it. [...] +_GL_EXTERN_C __declspec(dllimport) char **environ; >> >> But, other than that, an equivalent newlib patch would be ok. > > Before patching newlib, please note that Bruno's patch doesn't work on > 32-bit Cygwin. Projects (like emacs and clisp) that use gnulib's unistd > module with that patch will get link errors like this: > > undefined reference to `_imp__environ' > > I have no idea why this error occurs only on 32-bit. > > I've made Bruno aware of the problem, and I'm waiting to see what he > comes up with. > _imp__environ? Shouldn't that be _imp_environ for Cygwin? _imp__environ to me indicates the VC version of char **_environ instead. Is the correct header being used? -- cyg Simple -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: environ: fix link error on 64-bit Cygwin
On Feb 26 16:28, Ken Brown wrote: > On 1/31/2018 9:40 AM, Corinna Vinschen wrote: > > On Jan 31 07:52, Eric Blake wrote: > > > Forwarding from the gnulib list; is this something we should fix in > > > cygwin proper? > > > > Why does anybody remove the -Wl,--disable-auto-import flag? What for? > > The idea was to never use this flag on Cygwin and to get rid of the > > dllimport/dllexport nonsense... > > > > > On 01/31/2018 04:42 AM, Bruno Haible wrote: > > > > On 64-bit Cygwin, a libunistring build fails like this: > > > > [...] > > > > libtool: link: x86_64-pc-cygwin-gcc -g -O2 -Wl,--disable-auto-import -o > > > > .libs/test-environ.exe test-environ.o -L/usr/local/cygwin64/lib > > > > libtests.a ../lib/.libs/libunistring.dll.a -liconv libtests.a > > > > -L/usr/local/cygwin64/lib > > > > test-environ.o:test-environ.c:(.rdata$.refptr.environ[.refptr.environ]+0x0): > > > > undefined reference to `environ' > > > > collect2: error: ld returned 1 exit status > > > > > > > > This fixes it. > > > > [...] > > > > +_GL_EXTERN_C __declspec(dllimport) char **environ; > > > > But, other than that, an equivalent newlib patch would be ok. > > Before patching newlib, please note that Bruno's patch doesn't work on > 32-bit Cygwin. Projects (like emacs and clisp) that use gnulib's unistd > module with that patch will get link errors like this: > > undefined reference to `_imp__environ' > > I have no idea why this error occurs only on 32-bit. > > I've made Bruno aware of the problem, and I'm waiting to see what he comes > up with. No worries. I'll wait patiently for a newlib patch. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat signature.asc Description: PGP signature
Re: environ: fix link error on 64-bit Cygwin
On 1/31/2018 9:40 AM, Corinna Vinschen wrote: On Jan 31 07:52, Eric Blake wrote: Forwarding from the gnulib list; is this something we should fix in cygwin proper? Why does anybody remove the -Wl,--disable-auto-import flag? What for? The idea was to never use this flag on Cygwin and to get rid of the dllimport/dllexport nonsense... On 01/31/2018 04:42 AM, Bruno Haible wrote: On 64-bit Cygwin, a libunistring build fails like this: [...] libtool: link: x86_64-pc-cygwin-gcc -g -O2 -Wl,--disable-auto-import -o .libs/test-environ.exe test-environ.o -L/usr/local/cygwin64/lib libtests.a ../lib/.libs/libunistring.dll.a -liconv libtests.a -L/usr/local/cygwin64/lib test-environ.o:test-environ.c:(.rdata$.refptr.environ[.refptr.environ]+0x0): undefined reference to `environ' collect2: error: ld returned 1 exit status This fixes it. [...] +_GL_EXTERN_C __declspec(dllimport) char **environ; But, other than that, an equivalent newlib patch would be ok. Before patching newlib, please note that Bruno's patch doesn't work on 32-bit Cygwin. Projects (like emacs and clisp) that use gnulib's unistd module with that patch will get link errors like this: undefined reference to `_imp__environ' I have no idea why this error occurs only on 32-bit. I've made Bruno aware of the problem, and I'm waiting to see what he comes up with. Ken -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: environ: fix link error on 64-bit Cygwin
On Jan 31 07:52, Eric Blake wrote: > Forwarding from the gnulib list; is this something we should fix in > cygwin proper? Why does anybody remove the -Wl,--disable-auto-import flag? What for? The idea was to never use this flag on Cygwin and to get rid of the dllimport/dllexport nonsense... > On 01/31/2018 04:42 AM, Bruno Haible wrote: > > On 64-bit Cygwin, a libunistring build fails like this: > > [...] > > libtool: link: x86_64-pc-cygwin-gcc -g -O2 -Wl,--disable-auto-import -o > > .libs/test-environ.exe test-environ.o -L/usr/local/cygwin64/lib libtests.a > > ../lib/.libs/libunistring.dll.a -liconv libtests.a -L/usr/local/cygwin64/lib > > test-environ.o:test-environ.c:(.rdata$.refptr.environ[.refptr.environ]+0x0): > > undefined reference to `environ' > > collect2: error: ld returned 1 exit status > > > > This fixes it. > > [...] > > +_GL_EXTERN_C __declspec(dllimport) char **environ; But, other than that, an equivalent newlib patch would be ok. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat signature.asc Description: PGP signature
Re: environ: fix link error on 64-bit Cygwin
Forwarding from the gnulib list; is this something we should fix in
cygwin proper?
On 01/31/2018 04:42 AM, Bruno Haible wrote:
> On 64-bit Cygwin, a libunistring build fails like this:
>
> $ /bin/sh ../libtool --tag=CC --preserve-dup-deps --mode=link
> x86_64-pc-cygwin-gcc -g -O2 -L/usr/local/cygwin64/lib
> -Wl,--disable-auto-import -o test-environ.exe test-environ.o libtests.a
> ../lib/libunistring.la libtests.a
> libtool: link: x86_64-pc-cygwin-gcc -g -O2 -Wl,--disable-auto-import -o
> .libs/test-environ.exe test-environ.o -L/usr/local/cygwin64/lib libtests.a
> ../lib/.libs/libunistring.dll.a -liconv libtests.a -L/usr/local/cygwin64/lib
> test-environ.o:test-environ.c:(.rdata$.refptr.environ[.refptr.environ]+0x0):
> undefined reference to `environ'
> collect2: error: ld returned 1 exit status
>
> This fixes it.
>
>
> 2018-01-31 Bruno Haible <br...@clisp.org>
>
> environ: Fix link error on 64-bit Cygwin.
> * lib/unistd.in.h (environ): On Cygwin, redeclare with the
> __declspec(dllimport) attribute.
> * doc/posix-functions/environ.texi: Mention the Cygwin problem.
>
> diff --git a/doc/posix-functions/environ.texi
> b/doc/posix-functions/environ.texi
> index 34ac25a..a6c0095 100644
> --- a/doc/posix-functions/environ.texi
> +++ b/doc/posix-functions/environ.texi
> @@ -24,6 +24,9 @@ shared libraries on Mac OS X 10.5. Here is a workaround:
> Instead, one can use
> #define environ (*_NSGetEnviron())
> @end smallexample
> This works at all versions of Mac OS X.
> +@item
> +On Cygwin in 64-bit mode, references to this variable cause a link error when
> +the option @code{-Wl,--disable-auto-import} is in use.
> @end itemize
>
> Portability problems not fixed by Gnulib:
> diff --git a/lib/unistd.in.h b/lib/unistd.in.h
> index 6802e3b..4ef0ffa 100644
> --- a/lib/unistd.in.h
> +++ b/lib/unistd.in.h
> @@ -400,6 +400,13 @@ _GL_WARN_ON_USE (dup3, "dup3 is unportable - "
>
>
> #if @GNULIB_ENVIRON@
> +# if defined __CYGWIN__
> +/* The 'environ' variable is defined in a DLL. Therefore its declaration
> needs
> + the '__declspec(dllimport)' attribute, but the system's lacks
> it.
> + This leads to a link error on 64-bit Cygwin when the option
> + -Wl,--disable-auto-import is in use. */
> +_GL_EXTERN_C __declspec(dllimport) char **environ;
> +# endif
> # if !@HAVE_DECL_ENVIRON@
> /* Set of environment variables and values. An array of strings of the form
> "VARIABLE=VALUE", terminated with a NULL. */
>
>
>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
signature.asc
Description: OpenPGP digital signature
