1 files changed, 91 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/posix/writev.c b/REORG.TODO/sysdeps/posix/writev.c
new file mode 100644
index 0000000000..7ce1deb80f
--- /dev/null
+++ b/REORG.TODO/sysdeps/posix/writev.c
@@ -0,0 +1,91 @@
+/* Copyright (C) 1991-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <sys/param.h>
+#include <sys/uio.h>
+#include <errno.h>
+
+
+static void
+ifree (char **ptrp)
+{
+  free (*ptrp);
+}
+
+
+/* Write data pointed by the buffers described by VECTOR, which
+   is a vector of COUNT 'struct iovec's, to file descriptor FD.
+   The data is written in the order specified.
+   Operates just like 'write' (see <unistd.h>) except that the data
+   are taken from VECTOR instead of a contiguous buffer.  */
+ssize_t
+__writev (int fd, const struct iovec *vector, int count)
+{
+  /* Find the total number of bytes to be written.  */
+  size_t bytes = 0;
+  for (int i = 0; i < count; ++i)
+    {
+      /* Check for ssize_t overflow.  */
+      if (SSIZE_MAX - bytes < vector[i].iov_len)
+	{
+	  __set_errno (EINVAL);
+	  return -1;
+	}
+      bytes += vector[i].iov_len;
+    }
+
+  /* Allocate a temporary buffer to hold the data.  We should normally
+     use alloca since it's faster and does not require synchronization
+     with other threads.  But we cannot if the amount of memory
+     required is too large.  */
+  char *buffer;
+  char *malloced_buffer __attribute__ ((__cleanup__ (ifree))) = NULL;
+  if (__libc_use_alloca (bytes))
+    buffer = (char *) __alloca (bytes);
+  else
+    {
+      malloced_buffer = buffer = (char *) malloc (bytes);
+      if (buffer == NULL)
+	/* XXX I don't know whether it is acceptable to try writing
+	   the data in chunks.  Probably not so we just fail here.  */
+	return -1;
+    }
+
+  /* Copy the data into BUFFER.  */
+  size_t to_copy = bytes;
+  char *bp = buffer;
+  for (int i = 0; i < count; ++i)
+    {
+      size_t copy = MIN (vector[i].iov_len, to_copy);
+
+      bp = __mempcpy ((void *) bp, (void *) vector[i].iov_base, copy);
+
+      to_copy -= copy;
+      if (to_copy == 0)
+	break;
+    }
+
+  ssize_t bytes_written = __write (fd, buffer, bytes);
+
+  return bytes_written;
+}
+weak_alias (__writev, writev)