* Re: environ: fix link error on 64-bit Cygwin [not found] <36131639.liFsmjX0ip@omega> @ 2018-01-31 13:53 ` Eric Blake 2018-01-31 14:40 ` Corinna Vinschen 0 siblings, 1 reply; 5+ messages in thread From: Eric Blake @ 2018-01-31 13:53 UTC (permalink / raw) To: The Cygwin Mailing List [-- Attachment #1.1: Type: text/plain, Size: 2659 bytes --] 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 <bruno@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 <unistd.h> 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 [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 619 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: environ: fix link error on 64-bit Cygwin 2018-01-31 13:53 ` environ: fix link error on 64-bit Cygwin Eric Blake @ 2018-01-31 14:40 ` Corinna Vinschen 2018-02-26 21:28 ` Ken Brown 0 siblings, 1 reply; 5+ messages in thread From: Corinna Vinschen @ 2018-01-31 14:40 UTC (permalink / raw) To: cygwin [-- Attachment #1: Type: text/plain, Size: 1137 bytes --] 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 [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 833 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: environ: fix link error on 64-bit Cygwin 2018-01-31 14:40 ` Corinna Vinschen @ 2018-02-26 21:28 ` Ken Brown 2018-02-27 10:38 ` Corinna Vinschen 2018-02-27 14:10 ` cyg Simple 0 siblings, 2 replies; 5+ messages in thread From: Ken Brown @ 2018-02-26 21:28 UTC (permalink / raw) To: 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 ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: environ: fix link error on 64-bit Cygwin 2018-02-26 21:28 ` Ken Brown @ 2018-02-27 10:38 ` Corinna Vinschen 2018-02-27 14:10 ` cyg Simple 1 sibling, 0 replies; 5+ messages in thread From: Corinna Vinschen @ 2018-02-27 10:38 UTC (permalink / raw) To: cygwin [-- Attachment #1: Type: text/plain, Size: 1771 bytes --] 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 [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 833 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: environ: fix link error on 64-bit Cygwin 2018-02-26 21:28 ` Ken Brown 2018-02-27 10:38 ` Corinna Vinschen @ 2018-02-27 14:10 ` cyg Simple 1 sibling, 0 replies; 5+ messages in thread From: cyg Simple @ 2018-02-27 14:10 UTC (permalink / raw) To: 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 ^ permalink raw reply [flat|nested] 5+ messages in thread
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2018-01-31 13:53 ` environ: fix link error on 64-bit Cygwin Eric Blake
2018-01-31 14:40 ` Corinna Vinschen
2018-02-26 21:28 ` Ken Brown
2018-02-27 10:38 ` Corinna Vinschen
2018-02-27 14:10 ` cyg Simple
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