Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 115 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/generic/wordsize-32/getdents.c b/REORG.TODO/sysdeps/unix/sysv/linux/generic/wordsize-32/getdents.c
new file mode 100644
index 0000000000..9f1c991694
--- /dev/null
+++ b/REORG.TODO/sysdeps/unix/sysv/linux/generic/wordsize-32/getdents.c
@@ -0,0 +1,115 @@
+/* Copyright (C) 1993-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Simplified from sysdeps/unix/sysv/linux/getdents.c.
+
+   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 <alloca.h>
+#include <assert.h>
+#include <errno.h>
+#include <dirent.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/param.h>
+#include <sys/types.h>
+
+#include <sysdep.h>
+#include <sys/syscall.h>
+
+/* Pack the dirent64 struct down into 32-bit offset/inode fields, and
+   ensure that no overflow occurs.  */
+ssize_t
+__getdents (int fd, char *buf, size_t nbytes)
+{
+  union
+  {
+    struct dirent64 k;  /* Kernel structure.  */
+    struct dirent u;
+    char b[1];
+  } *kbuf = (void *) buf, *outp, *inp;
+  size_t kbytes = nbytes;
+  off64_t last_offset = -1;
+  ssize_t retval;
+
+  const size_t size_diff = (offsetof (struct dirent64, d_name)
+                            - offsetof (struct dirent, d_name));
+  if (nbytes <= sizeof (struct dirent))
+    {
+      kbytes = nbytes + offsetof (struct dirent64, d_name)
+        - offsetof (struct dirent, d_name);
+      kbuf = __alloca(kbytes);
+    }
+
+  retval = INLINE_SYSCALL (getdents64, 3, fd, kbuf, kbytes);
+  if (retval == -1)
+    return -1;
+
+  /* These two pointers might alias the same memory buffer.
+     Standard C requires that we always use the same type for them,
+     so we must use the union type.  */
+  inp = kbuf;
+  outp = (void *) buf;
+
+  while (&inp->b < &kbuf->b + retval)
+    {
+      const size_t alignment = __alignof__ (struct dirent);
+      /* Since inp->k.d_reclen is already aligned for the kernel
+         structure this may compute a value that is bigger
+         than necessary.  */
+      size_t old_reclen = inp->k.d_reclen;
+      size_t new_reclen = ((old_reclen - size_diff + alignment - 1)
+                           & ~(alignment - 1));
+
+      /* Copy the data out of the old structure into temporary space.
+         Then copy the name, which may overlap if BUF == KBUF.  */
+      const uint64_t d_ino = inp->k.d_ino;
+      const int64_t d_off = inp->k.d_off;
+      const uint8_t d_type = inp->k.d_type;
+
+      memmove (outp->u.d_name, inp->k.d_name,
+               old_reclen - offsetof (struct dirent64, d_name));
+
+      /* Now we have copied the data from INP and access only OUTP.  */
+
+      outp->u.d_ino = d_ino;
+      outp->u.d_off = d_off;
+      if ((sizeof (outp->u.d_ino) != sizeof (inp->k.d_ino)
+           && outp->u.d_ino != d_ino)
+          || (sizeof (outp->u.d_off) != sizeof (inp->k.d_off)
+              && outp->u.d_off != d_off))
+        {
+          /* Overflow.  If there was at least one entry before this one,
+             return them without error, otherwise signal overflow.  */
+          if (last_offset != -1)
+            {
+              __lseek64 (fd, last_offset, SEEK_SET);
+              return outp->b - buf;
+            }
+          __set_errno (EOVERFLOW);
+          return -1;
+        }
+
+      last_offset = d_off;
+      outp->u.d_reclen = new_reclen;
+      outp->u.d_type = d_type;
+
+      inp = (void *) inp + old_reclen;
+      outp = (void *) outp + new_reclen;
+    }
+
+  return outp->b - buf;
+}