2010/3/20 Eric Blake <ebl...@redhat.com>:
> Since commit 4e86671a, gethostname failed to compile on mingw.
> Gnulib's sys/socket.h includes winsock2.h, which then includes
> unistd.h prior to declaring gethostname. Therefore, unistd.h
> cannot replace gethostname until winsock2.h is complete, also
> fixing things if a .c includes <unistd.h> (or even <winsock2.h>)
> prior to <sys/socket.h>.
>
> * lib/sys_socket.in.h (includes): Set witness when including
> winsock2.h.
> * lib/unistd.in.h (includes): Likewise, after hoisting <winsock2.h>
> inclusion. Don't replace anything when included by winsock2.h.
> Reported by Matthias Bolte.
>
> Signed-off-by: Eric Blake <ebl...@redhat.com>
> ---
>
> I think this is more robust, but would appreciate another round
> of testing before I push.
>
> ChangeLog | 9 +++++++++
> lib/sys_socket.in.h | 7 ++++++-
> lib/unistd.in.h | 15 +++++++++++++--
> 3 files changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/ChangeLog b/ChangeLog
> index de054fa..2125639 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,12 @@
> +2010-03-19 Eric Blake <ebl...@redhat.com>
> +
> + gethostname: fix build on mingw
> + * lib/sys_socket.in.h (includes): Set witness when including
> + winsock2.h.
> + * lib/unistd.in.h (includes): Don't replace anything when included
> + by winsock2.h.
> + Reported by Matthias Bolte.
> +
> 2010-02-17 Eric Blake <e...@byu.net>
>
> manywarnings: add more warnings
> diff --git a/lib/sys_socket.in.h b/lib/sys_socket.in.h
> index 006a901..b34b506 100644
> --- a/lib/sys_socket.in.h
> +++ b/lib/sys_socket.in.h
> @@ -28,7 +28,10 @@
> - On Cygwin 1.5.x we have a sequence of nested includes
> <sys/socket.h> -> <cygwin/socket.h> -> <asm/socket.h> -> <cygwin/if.h>,
> and the latter includes <sys/socket.h>. In this situation, the functions
> - are not yet declared, therefore we cannot provide the C++ aliases. */
> + are not yet declared, therefore we cannot provide the C++ aliases.
> + - On mingw, <sys/socket.h> -> <winsock2.h> -> <unistd.h>, and the latter
> + includes <winsock2.h>. In this situation, functions like gethostname
> + are not yet declared, therefore we must defer. */
>
> �...@include_next@ @NEXT_SYS_SOCKET_H@
>
> @@ -129,7 +132,9 @@ struct sockaddr_storage
>
>
> # if @HAVE_WINSOCK2_H@
> +# define _GL_INCLUDING_WINSOCK2_H
> # include <winsock2.h>
> +# undef _GL_INCLUDING_WINSOCK2_H
> # endif
> # if @HAVE_WS2TCPIP_H@
> # include <ws2tcpip.h>
> diff --git a/lib/unistd.in.h b/lib/unistd.in.h
> index b74484a..a57ba37 100644
> --- a/lib/unistd.in.h
> +++ b/lib/unistd.in.h
> @@ -26,7 +26,19 @@
> # @INCLUDE_NEXT@ @NEXT_UNISTD_H@
> #endif
>
> -#ifndef _GL_UNISTD_H
> +/* On mingw, <winsock2.h> includes <unistd.h> prior to declaring
> + gethostname, but we want to replace gethostname. We must ensure
> + that <winsock2.h> is completely included first. */
> +#if @GNULIB_GETHOSTNAME@
> +/* Get all possible declarations of gethostname(). */
> +# if @UNISTD_H_HAVE_WINSOCK2_H@
> +# define _GL_INCLUDING_WINSOCK2_H
> +# include <winsock2.h>
> +# undef _GL_INCLUDING_WINSOCK2_H
> +# endif
> +#endif
> +
> +#if !defined _GL_UNISTD_H && !defined _GL_INCLUDING_WINSOCK2_H
> #define _GL_UNISTD_H
>
> /* NetBSD 5.0 mis-defines NULL. Also get size_t. */
> @@ -76,7 +88,6 @@
> #if @GNULIB_GETHOSTNAME@
> /* Get all possible declarations of gethostname(). */
> # if @UNISTD_H_HAVE_WINSOCK2_H@
> -# include <winsock2.h>
> # if !defined _GL_SYS_SOCKET_H
> # undef socket
> # define socket socket_used_without_including_sys_socket_h
> --
> 1.6.6.1
>
If I apply the attached diff on top of this patch the problem is
fixed. It compiles without errors, I can include <unistd.h> before
<sys/socket.h> and I can include <winsock2.h> before <sys/socket.h> as
long as the <winsock2.h> include is wrapped in #define/#undef
_GL_INCLUDING_WINSOCK2_H.
The important part is
-# if @UNISTD_H_HAVE_WINSOCK2_H@
+# if @UNISTD_H_HAVE_WINSOCK2_H@ && !defined _GL_INCLUDING_WINSOCK2_H
This stops the <winsock2.h>-includes-<unistd.h>-case from undefining
_GL_INCLUDING_WINSOCK2_H too early.
Matthias
diff --git a/lib/poll.c b/lib/poll.c
index 90d99d9..024ffa9 100644
--- a/lib/poll.c
+++ b/lib/poll.c
@@ -35,7 +35,9 @@
#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
# define WIN32_NATIVE
-# include <winsock2.h>
+# define _GL_INCLUDING_WINSOCK2_H
+# include <winsock2.h>
+# undef _GL_INCLUDING_WINSOCK2_H
# include <windows.h>
# include <io.h>
# include <stdio.h>
diff --git a/lib/select.c b/lib/select.c
index 3564566..66468bf 100644
--- a/lib/select.c
+++ b/lib/select.c
@@ -31,7 +31,9 @@
#include <errno.h>
#include <limits.h>
-#include <winsock2.h>
+#define _GL_INCLUDING_WINSOCK2_H
+# include <winsock2.h>
+#undef _GL_INCLUDING_WINSOCK2_H
#include <windows.h>
#include <io.h>
#include <stdio.h>
diff --git a/lib/strerror.c b/lib/strerror.c
index b0df778..c13aa1c 100644
--- a/lib/strerror.c
+++ b/lib/strerror.c
@@ -26,7 +26,9 @@
# if GNULIB_defined_ESOCK /* native Windows platforms */
# if HAVE_WINSOCK2_H
-# include <winsock2.h>
+# define _GL_INCLUDING_WINSOCK2_H
+# include <winsock2.h>
+# undef _GL_INCLUDING_WINSOCK2_H
# endif
# endif
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index 7c7ecd8..13bdda5 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -31,7 +31,7 @@
that <winsock2.h> is completely included first. */
#if @GNULIB_GETHOSTNAME@
/* Get all possible declarations of gethostname(). */
-# if @UNISTD_H_HAVE_WINSOCK2_H@
+# if @UNISTD_H_HAVE_WINSOCK2_H@ && !defined _GL_INCLUDING_WINSOCK2_H
# define _GL_INCLUDING_WINSOCK2_H
# include <winsock2.h>
# undef _GL_INCLUDING_WINSOCK2_H
