Implement a way to opt out from MSVC support.

This is useful for Emacs.

* modules/msvc-nothrow (configure.ac): Invoke gl_MODULE_INDICATOR.
* lib/accept4.c: Include <io.h> as an alternative to msvc-nothrow.h.
* lib/error.c: Likewise.
* lib/fcntl.c: Likewise.
* lib/flock.c: Likewise.
* lib/fstat.c: Likewise.
* lib/fsync.c: Likewise.
* lib/ioctl.c: Likewise.
* lib/isapipe.c: Likewise.
* lib/lseek.c: Likewise.
* lib/nonblocking.c: Likewise.
* lib/poll.c: Likewise.
* lib/select.c: Likewise.
* lib/sockets.h: Likewise.
* lib/sockets.c: Likewise.
* lib/stdio-read.c: Likewise.
* lib/stdio-write.c: Likewise.
* lib/utimens.c: Likewise.
* lib/w32sock.h: Likewise.
* lib/w32spawn.h: Likewise.
* tests/test-cloexec.c: Likewise.
* tests/test-dup-safer.c: Likewise.
* tests/test-dup2.c: Likewise.
* tests/test-dup3.c: Likewise.
* tests/test-fcntl.c: Likewise.
* tests/test-pipe.c: Likewise.
* tests/test-pipe2.c: Likewise.
* lib/ftruncate.c: Likewise.
(chsize_nothrow): Renamed from chsize.
* lib/msvc-nothrow.c: Don't include msvc-inval.h if
HAVE_MSVC_INVALID_PARAMETER_HANDLER is not defined.
* lib/close.c: Likewise.
* lib/dup.c: Likewise.
* lib/fclose.c: Likewise.
* lib/raise.c: Likewise.
* tests/test-fgetc.c: Likewise.
* tests/test-fputc.c: Likewise.
* tests/test-fread.c: Likewise.
* tests/test-fwrite.c: Likewise.
* lib/getdtablesize.c: Likewise.
(_setmaxstdio_nothrow): Renamed from _setmaxstdio.
* lib/isatty.c: Don't include msvc-inval.h if
HAVE_MSVC_INVALID_PARAMETER_HANDLER is not defined.
Include <io.h> as an alternative to msvc-nothrow.h.
* lib/read.c: Likewise.
* lib/write.c: Likewise.
* lib/dup2.c: Likewise.
(dup2_nothrow): New function.
(ms_windows_dup2): Use it.
* m4/close.m4 (gl_FUNC_CLOSE): Invoke gl_MSVC_INVAL and test
HAVE_MSVC_INVALID_PARAMETER_HANDLER only if gl_MSVC_INVAL is defined.
* m4/dup.m4 (gl_FUNC_DUP): Likewise.
* m4/fdopen.m4 (gl_FUNC_FDOPEN): Likewise.
* m4/raise.m4 (gl_FUNC_RAISE): Likewise.
* m4/read.m4 (gl_FUNC_READ): Likewise.
* m4/write.m4 (gl_FUNC_WRITE): Likewise.
* doc/windows-without-msvc.texi: New file.
* doc/gnulib.texi (Native Windows Support without MSVC Support): New
section.

30 files changed, 184 insertions, 52 deletions

diff --git a/lib/accept4.c b/lib/accept4.c
index 040fb9ff6a..997f75ad8b 100644
--- a/lib/accept4.c
+++ b/lib/accept4.c
@@ -22,7 +22,11 @@
 #include <errno.h>
 #include <fcntl.h>
 #include "binary-io.h"
-#include "msvc-nothrow.h"
+#if GNULIB_MSVC_NOTHROW
+# include "msvc-nothrow.h"
+#else
+# include <io.h>
+#endif
 
 #ifndef SOCK_CLOEXEC
 # define SOCK_CLOEXEC 0
diff --git a/lib/close.c b/lib/close.c
index 3e451871f5..6a72c32299 100644
--- a/lib/close.c
+++ b/lib/close.c
@@ -22,7 +22,9 @@
 #include <errno.h>
 
 #include "fd-hook.h"
-#include "msvc-inval.h"
+#if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+# include "msvc-inval.h"
+#endif
 
 #undef close
 
diff --git a/lib/dup.c b/lib/dup.c
index 819e9e3780..69887b0c35 100644
--- a/lib/dup.c
+++ b/lib/dup.c
@@ -22,7 +22,9 @@
 
 #include <errno.h>
 
-#include "msvc-inval.h"
+#if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+# include "msvc-inval.h"
+#endif
 
 #undef dup
 
diff --git a/lib/dup2.c b/lib/dup2.c
index c0c7cadf4a..002dc8c76c 100644
--- a/lib/dup2.c
+++ b/lib/dup2.c
@@ -35,10 +35,39 @@
 #  define WIN32_LEAN_AND_MEAN
 #  include <windows.h>
 
-#  include "msvc-inval.h"
+#  if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+#   include "msvc-inval.h"
+#  endif
 
 /* Get _get_osfhandle.  */
-#  include "msvc-nothrow.h"
+#  if GNULIB_MSVC_NOTHROW
+#   include "msvc-nothrow.h"
+#  else
+#   include <io.h>
+#  endif
+
+#  if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+static int
+dup2_nothrow (int fd, int desired_fd)
+{
+  int result;
+
+  TRY_MSVC_INVAL
+    {
+      result = dup2 (fd, desired_fd);
+    }
+  CATCH_MSVC_INVAL
+    {
+      errno = EBADF;
+      result = -1;
+    }
+  DONE_MSVC_INVAL;
+
+  return result;
+}
+#  else
+#   define dup2_nothrow dup2
+#  endif
 
 static int
 ms_windows_dup2 (int fd, int desired_fd)
@@ -66,16 +95,7 @@ ms_windows_dup2 (int fd, int desired_fd)
       return -1;
     }
 
-  TRY_MSVC_INVAL
-    {
-      result = dup2 (fd, desired_fd);
-    }
-  CATCH_MSVC_INVAL
-    {
-      errno = EBADF;
-      result = -1;
-    }
-  DONE_MSVC_INVAL;
+  result = dup2_nothrow (fd, desired_fd);
 
   if (result == 0)
     result = desired_fd;
diff --git a/lib/error.c b/lib/error.c
index ed9b37a955..418d1ab8de 100644
--- a/lib/error.c
+++ b/lib/error.c
@@ -98,7 +98,11 @@ extern void __error_at_line (int status, int errnum, const char *file_name,
 #  define WIN32_LEAN_AND_MEAN
 #  include <windows.h>
 /* Get _get_osfhandle.  */
-#  include "msvc-nothrow.h"
+#  if GNULIB_MSVC_NOTHROW
+#   include "msvc-nothrow.h"
+#  else
+#   include <io.h>
+#  endif
 # endif
 
 /* The gnulib override of fcntl is not needed in this file.  */
diff --git a/lib/fclose.c b/lib/fclose.c
index facff2bd85..fc6f6087b3 100644
--- a/lib/fclose.c
+++ b/lib/fclose.c
@@ -23,7 +23,9 @@
 #include <unistd.h>
 
 #include "freading.h"
-#include "msvc-inval.h"
+#if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+# include "msvc-inval.h"
+#endif
 
 #undef fclose
 
diff --git a/lib/fcntl.c b/lib/fcntl.c
index afe15468ff..d4dd144e05 100644
--- a/lib/fcntl.c
+++ b/lib/fcntl.c
@@ -38,7 +38,11 @@
 # include <windows.h>
 
 /* Get _get_osfhandle.  */
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 /* Upper bound on getdtablesize().  See lib/getdtablesize.c.  */
 # define OPEN_MAX_MAX 0x10000
diff --git a/lib/flock.c b/lib/flock.c
index 7698e43ffc..0c55d521cf 100644
--- a/lib/flock.c
+++ b/lib/flock.c
@@ -33,7 +33,11 @@
 # include <errno.h>
 
 /* _get_osfhandle */
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 /* Determine the current size of a file.  Because the other braindead
  * APIs we'll call need lower/upper 32 bit pairs, keep the file size
diff --git a/lib/fstat.c b/lib/fstat.c
index a4896e3a77..605ac7d85e 100644
--- a/lib/fstat.c
+++ b/lib/fstat.c
@@ -56,7 +56,11 @@ orig_fstat (int fd, struct stat *buf)
 #ifdef WINDOWS_NATIVE
 # define WIN32_LEAN_AND_MEAN
 # include <windows.h>
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 # include "stat-w32.h"
 #endif
 
diff --git a/lib/fsync.c b/lib/fsync.c
index d7de6d8b19..846f308720 100644
--- a/lib/fsync.c
+++ b/lib/fsync.c
@@ -34,7 +34,11 @@
 # include <errno.h>
 
 /* Get _get_osfhandle.  */
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 int
 fsync (int fd)
diff --git a/lib/ftruncate.c b/lib/ftruncate.c
index 913df19cbc..f0ecae27b4 100644
--- a/lib/ftruncate.c
+++ b/lib/ftruncate.c
@@ -38,7 +38,11 @@
 #  include <windows.h>
 
 /* Get _get_osfhandle.  */
-#  include "msvc-nothrow.h"
+#  if GNULIB_MSVC_NOTHROW
+#   include "msvc-nothrow.h"
+#  else
+#   include <io.h>
+#  endif
 
 static BOOL
 SetFileSize (HANDLE h, LONGLONG size)
@@ -175,13 +179,14 @@ chsize_nothrow (int fd, long length)
 
   return result;
 }
-#   define chsize chsize_nothrow
+#  else
+#   define chsize_nothrow chsize
 #  endif
 
 int
 ftruncate (int fd, off_t length)
 {
-  return chsize (fd, length);
+  return chsize_nothrow (fd, length);
 }
 
 # endif
diff --git a/lib/getdtablesize.c b/lib/getdtablesize.c
index 7fabb51e2c..c356cf4aa9 100644
--- a/lib/getdtablesize.c
+++ b/lib/getdtablesize.c
@@ -24,7 +24,9 @@
 
 # include <stdio.h>
 
-# include "msvc-inval.h"
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+#  include "msvc-inval.h"
+# endif
 
 # if HAVE_MSVC_INVALID_PARAMETER_HANDLER
 static int
@@ -44,7 +46,8 @@ _setmaxstdio_nothrow (int newmax)
 
   return result;
 }
-#  define _setmaxstdio _setmaxstdio_nothrow
+# else
+#  define _setmaxstdio_nothrow _setmaxstdio
 # endif
 
 /* Cache for the previous getdtablesize () result.  Safe to cache because
@@ -76,9 +79,9 @@ getdtablesize (void)
          freed when we call _setmaxstdio with the original value.  */
       int orig_max_stdio = _getmaxstdio ();
       unsigned int bound;
-      for (bound = 0x10000; _setmaxstdio (bound) < 0; bound = bound / 2)
+      for (bound = 0x10000; _setmaxstdio_nothrow (bound) < 0; bound = bound / 2)
         ;
-      _setmaxstdio (orig_max_stdio);
+      _setmaxstdio_nothrow (orig_max_stdio);
       dtablesize = bound;
     }
   return dtablesize;
diff --git a/lib/ioctl.c b/lib/ioctl.c
index a28a3ae437..f1425589cf 100644
--- a/lib/ioctl.c
+++ b/lib/ioctl.c
@@ -52,7 +52,11 @@ rpl_ioctl (int fd, int request, ... /* {void *,char *} arg */)
 
 # include "fd-hook.h"
 /* Get _get_osfhandle.  */
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 static int
 primary_ioctl (int fd, int request, void *arg)
diff --git a/lib/isapipe.c b/lib/isapipe.c
index dbc63b5f49..535ece933b 100644
--- a/lib/isapipe.c
+++ b/lib/isapipe.c
@@ -30,7 +30,11 @@
 # include <windows.h>
 
 /* Get _get_osfhandle.  */
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 int
 isapipe (int fd)
diff --git a/lib/isatty.c b/lib/isatty.c
index f050426c5f..dba4380561 100644
--- a/lib/isatty.c
+++ b/lib/isatty.c
@@ -27,10 +27,16 @@
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 
-#include "msvc-inval.h"
+#if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+# include "msvc-inval.h"
+#endif
 
 /* Get _get_osfhandle().  */
-#include "msvc-nothrow.h"
+#if GNULIB_MSVC_NOTHROW
+# include "msvc-nothrow.h"
+#else
+# include <io.h>
+#endif
 
 static BOOL IsConsoleHandle (HANDLE h)
 {
diff --git a/lib/lseek.c b/lib/lseek.c
index e603539b36..9c991a3d30 100644
--- a/lib/lseek.c
+++ b/lib/lseek.c
@@ -24,7 +24,11 @@
 /* Get GetFileType.  */
 # include <windows.h>
 /* Get _get_osfhandle.  */
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 #else
 # include <sys/stat.h>
 #endif
diff --git a/lib/msvc-nothrow.c b/lib/msvc-nothrow.c
index 300ed41aaf..86a88082ff 100644
--- a/lib/msvc-nothrow.c
+++ b/lib/msvc-nothrow.c
@@ -24,7 +24,9 @@
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 
-#include "msvc-inval.h"
+#if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+# include "msvc-inval.h"
+#endif
 
 #undef _get_osfhandle
 
diff --git a/lib/nonblocking.c b/lib/nonblocking.c
index 3d031aa834..b9ed86a8ba 100644
--- a/lib/nonblocking.c
+++ b/lib/nonblocking.c
@@ -32,7 +32,11 @@
 # define WIN32_LEAN_AND_MEAN
 # include <windows.h>
 
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 int
 get_nonblocking_flag (int desc)
diff --git a/lib/poll.c b/lib/poll.c
index 078b1bab41..9115bcd4a9 100644
--- a/lib/poll.c
+++ b/lib/poll.c
@@ -41,7 +41,11 @@
 # include <io.h>
 # include <stdio.h>
 # include <conio.h>
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 #else
 # include <sys/time.h>
 # include <unistd.h>
diff --git a/lib/raise.c b/lib/raise.c
index d3325a630e..0a6d8ca9d8 100644
--- a/lib/raise.c
+++ b/lib/raise.c
@@ -27,7 +27,9 @@
 
 # include <errno.h>
 
-# include "msvc-inval.h"
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+#  include "msvc-inval.h"
+# endif
 
 # undef raise
 
diff --git a/lib/read.c b/lib/read.c
index 08108f7f7b..a9b943ff90 100644
--- a/lib/read.c
+++ b/lib/read.c
@@ -28,8 +28,14 @@
 # define WIN32_LEAN_AND_MEAN  /* avoid including junk */
 # include <windows.h>
 
-# include "msvc-inval.h"
-# include "msvc-nothrow.h"
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+#  include "msvc-inval.h"
+# endif
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 # undef read
 
diff --git a/lib/select.c b/lib/select.c
index ac86c499d4..01b19823fb 100644
--- a/lib/select.c
+++ b/lib/select.c
@@ -39,7 +39,11 @@
 /* Get the overridden 'struct timeval'.  */
 #include <sys/time.h>
 
-#include "msvc-nothrow.h"
+#if GNULIB_MSVC_NOTHROW
+# include "msvc-nothrow.h"
+#else
+# include <io.h>
+#endif
 
 #undef select
 
diff --git a/lib/sockets.c b/lib/sockets.c
index 9333ee4dd8..028e20ec0e 100644
--- a/lib/sockets.c
+++ b/lib/sockets.c
@@ -28,7 +28,11 @@
 # include <sys/socket.h>
 
 # include "fd-hook.h"
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 /* Get set_winsock_errno, FD_TO_SOCKET etc. */
 # include "w32sock.h"
diff --git a/lib/sockets.h b/lib/sockets.h
index 8392e57566..23ad74d2fa 100644
--- a/lib/sockets.h
+++ b/lib/sockets.h
@@ -18,7 +18,7 @@
 /* Written by Simon Josefsson */
 
 #ifndef SOCKETS_H
-# define SOCKETS_H 1
+#define SOCKETS_H 1
 
 #define SOCKETS_1_0 0x0001
 #define SOCKETS_1_1 0x0101
@@ -43,9 +43,13 @@ int gl_sockets_cleanup (void)
    other library that only accepts sockets. */
 #ifdef WINDOWS_SOCKETS
 
-#include <sys/socket.h>
+# include <sys/socket.h>
 
-#include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 static inline SOCKET
 gl_fd_to_handle (int fd)
@@ -55,7 +59,7 @@ gl_fd_to_handle (int fd)
 
 #else
 
-#define gl_fd_to_handle(x) (x)
+# define gl_fd_to_handle(x) (x)
 
 #endif /* WINDOWS_SOCKETS */
 
diff --git a/lib/stdio-read.c b/lib/stdio-read.c
index 8caf2f003c..98db74966e 100644
--- a/lib/stdio-read.c
+++ b/lib/stdio-read.c
@@ -37,7 +37,11 @@
 #  define WIN32_LEAN_AND_MEAN  /* avoid including junk */
 #  include <windows.h>
 
-#  include "msvc-nothrow.h"
+#  if GNULIB_MSVC_NOTHROW
+#   include "msvc-nothrow.h"
+#  else
+#   include <io.h>
+#  endif
 
 #  define CALL_WITH_ERRNO_FIX(RETTYPE, EXPRESSION, FAILED) \
   if (ferror (stream))                                                        \
diff --git a/lib/stdio-write.c b/lib/stdio-write.c
index 8ad693bc62..34b22f50ac 100644
--- a/lib/stdio-write.c
+++ b/lib/stdio-write.c
@@ -39,7 +39,11 @@
 #  define WIN32_LEAN_AND_MEAN  /* avoid including junk */
 #  include <windows.h>
 
-#  include "msvc-nothrow.h"
+#  if GNULIB_MSVC_NOTHROW
+#   include "msvc-nothrow.h"
+#  else
+#   include <io.h>
+#  endif
 
 #  if GNULIB_NONBLOCKING
 #   define CLEAR_ERRNO \
diff --git a/lib/utimens.c b/lib/utimens.c
index b4bfa8e322..ff4eab073c 100644
--- a/lib/utimens.c
+++ b/lib/utimens.c
@@ -44,7 +44,11 @@
 # define USE_SETFILETIME
 # define WIN32_LEAN_AND_MEAN
 # include <windows.h>
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 #endif
 
 /* Avoid recursion with rpl_futimens or rpl_utimensat.  */
diff --git a/lib/w32sock.h b/lib/w32sock.h
index 8ac8ab7751..2f753fb4c9 100644
--- a/lib/w32sock.h
+++ b/lib/w32sock.h
@@ -26,7 +26,11 @@
 #include <io.h>
 
 /* Get _get_osfhandle().  */
-#include "msvc-nothrow.h"
+#if GNULIB_MSVC_NOTHROW
+# include "msvc-nothrow.h"
+#else
+# include <io.h>
+#endif
 
 #define FD_TO_SOCKET(fd)   ((SOCKET) _get_osfhandle ((fd)))
 #define SOCKET_TO_FD(fh)   (_open_osfhandle ((intptr_t) (fh), O_RDWR | O_BINARY))
diff --git a/lib/w32spawn.h b/lib/w32spawn.h
index 7932662700..26ff658aa2 100644
--- a/lib/w32spawn.h
+++ b/lib/w32spawn.h
@@ -30,7 +30,11 @@
 #include <errno.h>
 
 /* Get _get_osfhandle().  */
-#include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 #include "cloexec.h"
 #include "xalloc.h"
diff --git a/lib/write.c b/lib/write.c
index 6a3b623e68..b81db62081 100644
--- a/lib/write.c
+++ b/lib/write.c
@@ -34,8 +34,14 @@
 # define WIN32_LEAN_AND_MEAN  /* avoid including junk */
 # include <windows.h>
 
-# include "msvc-inval.h"
-# include "msvc-nothrow.h"
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+#  include "msvc-inval.h"
+# endif
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 # undef write