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.

6 files changed, 43 insertions, 30 deletions

diff --git a/m4/close.m4 b/m4/close.m4
index 005a43ae1e..ed357ab924 100644
--- a/m4/close.m4
+++ b/m4/close.m4
@@ -1,4 +1,4 @@
-# close.m4 serial 8
+# close.m4 serial 9
 dnl Copyright (C) 2008-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,10 +7,12 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_CLOSE],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
-  AC_REQUIRE([gl_MSVC_INVAL])
-  if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
-    REPLACE_CLOSE=1
-  fi
+  m4_ifdef([gl_MSVC_INVAL], [
+    AC_REQUIRE([gl_MSVC_INVAL])
+    if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
+      REPLACE_CLOSE=1
+    fi
+  ])
   m4_ifdef([gl_PREREQ_SYS_H_WINSOCK2], [
     gl_PREREQ_SYS_H_WINSOCK2
     if test $UNISTD_H_HAVE_WINSOCK2_H = 1; then
diff --git a/m4/dup.m4 b/m4/dup.m4
index 74fa9bd3dc..75307cbb89 100644
--- a/m4/dup.m4
+++ b/m4/dup.m4
@@ -1,4 +1,4 @@
-# dup.m4 serial 4
+# dup.m4 serial 5
 dnl Copyright (C) 2011-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,10 +7,12 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_DUP],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
-  AC_REQUIRE([gl_MSVC_INVAL])
-  if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
-    REPLACE_DUP=1
-  fi
+  m4_ifdef([gl_MSVC_INVAL], [
+    AC_REQUIRE([gl_MSVC_INVAL])
+    if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
+      REPLACE_DUP=1
+    fi
+  ])
   dnl Replace dup() for supporting the gnulib-defined fchdir() function,
   dnl to keep fchdir's bookkeeping up-to-date.
   m4_ifdef([gl_FUNC_FCHDIR], [
diff --git a/m4/fdopen.m4 b/m4/fdopen.m4
index 8e8619cc8d..42f928efd0 100644
--- a/m4/fdopen.m4
+++ b/m4/fdopen.m4
@@ -1,4 +1,4 @@
-# fdopen.m4 serial 3
+# fdopen.m4 serial 4
 dnl Copyright (C) 2011-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,10 +8,13 @@ AC_DEFUN([gl_FUNC_FDOPEN],
 [
   AC_REQUIRE([gl_STDIO_H_DEFAULTS])
   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
-  AC_REQUIRE([gl_MSVC_INVAL])
-  if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
-    REPLACE_FDOPEN=1
-  else
+  m4_ifdef([gl_MSVC_INVAL], [
+    AC_REQUIRE([gl_MSVC_INVAL])
+    if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
+      REPLACE_FDOPEN=1
+    fi
+  ])
+  if test $REPLACE_FDOPEN = 0; then
     dnl Test whether fdopen() sets errno when it fails due to a bad fd argument.
     AC_CACHE_CHECK([whether fdopen sets errno], [gl_cv_func_fdopen_works],
       [
diff --git a/m4/raise.m4 b/m4/raise.m4
index 28c2e0b5ce..fe6e06858e 100644
--- a/m4/raise.m4
+++ b/m4/raise.m4
@@ -1,4 +1,4 @@
-# raise.m4 serial 3
+# raise.m4 serial 4
 dnl Copyright (C) 2011-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,14 +8,16 @@ AC_DEFUN([gl_FUNC_RAISE],
 [
   AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
   AC_REQUIRE([AC_CANONICAL_HOST])
-  AC_REQUIRE([gl_MSVC_INVAL])
   AC_CHECK_FUNCS([raise])
   if test $ac_cv_func_raise = no; then
     HAVE_RAISE=0
   else
-    if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
-      REPLACE_RAISE=1
-    fi
+    m4_ifdef([gl_MSVC_INVAL], [
+      AC_REQUIRE([gl_MSVC_INVAL])
+      if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
+        REPLACE_RAISE=1
+      fi
+    ])
     m4_ifdef([gl_SIGNALBLOCKING], [
       gl_SIGNALBLOCKING
       if test $HAVE_POSIX_SIGNALBLOCKING = 0; then
diff --git a/m4/read.m4 b/m4/read.m4
index 36249abdcd..24668028ea 100644
--- a/m4/read.m4
+++ b/m4/read.m4
@@ -1,4 +1,4 @@
-# read.m4 serial 4
+# read.m4 serial 5
 dnl Copyright (C) 2011-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,10 +7,12 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_READ],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
-  AC_REQUIRE([gl_MSVC_INVAL])
-  if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
-    REPLACE_READ=1
-  fi
+  m4_ifdef([gl_MSVC_INVAL], [
+    AC_REQUIRE([gl_MSVC_INVAL])
+    if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
+      REPLACE_READ=1
+    fi
+  ])
   dnl This ifdef is just an optimization, to avoid performing a configure
   dnl check whose result is not used. It does not make the test of
   dnl GNULIB_UNISTD_H_NONBLOCKING or GNULIB_NONBLOCKING redundant.
diff --git a/m4/write.m4 b/m4/write.m4
index fd46acc1b0..2f4a23538e 100644
--- a/m4/write.m4
+++ b/m4/write.m4
@@ -1,4 +1,4 @@
-# write.m4 serial 5
+# write.m4 serial 6
 dnl Copyright (C) 2008-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,10 +7,12 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_WRITE],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
-  AC_REQUIRE([gl_MSVC_INVAL])
-  if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
-    REPLACE_WRITE=1
-  fi
+  m4_ifdef([gl_MSVC_INVAL], [
+    AC_REQUIRE([gl_MSVC_INVAL])
+    if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
+      REPLACE_WRITE=1
+    fi
+  ])
   dnl This ifdef is just an optimization, to avoid performing a configure
   dnl check whose result is not used. It does not make the test of
   dnl GNULIB_UNISTD_H_SIGPIPE or GNULIB_SIGPIPE redundant.