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, 234 insertions, 0 deletions

diff --git a/REORG.TODO/include/inline-hashtab.h b/REORG.TODO/include/inline-hashtab.h
new file mode 100644
index 0000000000..b0f5982a44
--- /dev/null
+++ b/REORG.TODO/include/inline-hashtab.h
@@ -0,0 +1,234 @@
+/* Fully-inline hash table, used mainly for managing TLS descriptors.
+   Copyright (C) 1999-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Alexandre Oliva  <aoliva@redhat.com>
+
+   This file is derived from a 2003's version of libiberty's
+   hashtab.c, contributed by Vladimir Makarov (vmakarov@cygnus.com),
+   but with most adaptation points and support for deleting elements
+   removed.
+
+   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/>.  */
+
+#ifndef INLINE_HASHTAB_H
+# define INLINE_HASHTAB_H 1
+
+extern void weak_function free (void *ptr);
+
+struct hashtab
+{
+  /* Table itself.  */
+  void **entries;
+
+  /* Current size (in entries) of the hash table */
+  size_t size;
+
+  /* Current number of elements.  */
+  size_t n_elements;
+
+  /* Free function for the entries array.  This may vary depending on
+     how early the array was allocated.  If it is NULL, then the array
+     can't be freed.  */
+  void (*free) (void *ptr);
+};
+
+inline static struct hashtab *
+htab_create (void)
+{
+  struct hashtab *ht = malloc (sizeof (struct hashtab));
+
+  if (! ht)
+    return NULL;
+  ht->size = 3;
+  ht->entries = malloc (sizeof (void *) * ht->size);
+  ht->free = free;
+  if (! ht->entries)
+    {
+      if (ht->free)
+	ht->free (ht);
+      return NULL;
+    }
+
+  ht->n_elements = 0;
+
+  memset (ht->entries, 0, sizeof (void *) * ht->size);
+
+  return ht;
+}
+
+/* This is only called from _dl_unmap, so it's safe to call
+   free().  */
+inline static void
+htab_delete (struct hashtab *htab)
+{
+  int i;
+
+  for (i = htab->size - 1; i >= 0; i--)
+    free (htab->entries[i]);
+
+  if (htab->free)
+    htab->free (htab->entries);
+  free (htab);
+}
+
+/* Similar to htab_find_slot, but without several unwanted side effects:
+    - Does not call htab->eq_f when it finds an existing entry.
+    - Does not change the count of elements/searches/collisions in the
+      hash table.
+   This function also assumes there are no deleted entries in the table.
+   HASH is the hash value for the element to be inserted.  */
+
+inline static void **
+find_empty_slot_for_expand (struct hashtab *htab, int hash)
+{
+  size_t size = htab->size;
+  unsigned int index = hash % size;
+  void **slot = htab->entries + index;
+  int hash2;
+
+  if (! *slot)
+    return slot;
+
+  hash2 = 1 + hash % (size - 2);
+  for (;;)
+    {
+      index += hash2;
+      if (index >= size)
+	index -= size;
+
+      slot = htab->entries + index;
+      if (! *slot)
+	return slot;
+    }
+}
+
+/* The following function changes size of memory allocated for the
+   entries and repeatedly inserts the table elements.  The occupancy
+   of the table after the call will be about 50%.  Naturally the hash
+   table must already exist.  Remember also that the place of the
+   table entries is changed.  If memory allocation failures are allowed,
+   this function will return zero, indicating that the table could not be
+   expanded.  If all goes well, it will return a non-zero value.  */
+
+inline static int
+htab_expand (struct hashtab *htab, int (*hash_fn) (void *))
+{
+  void **oentries;
+  void **olimit;
+  void **p;
+  void **nentries;
+  size_t nsize;
+
+  oentries = htab->entries;
+  olimit = oentries + htab->size;
+
+  /* Resize only when table after removal of unused elements is either
+     too full or too empty.  */
+  if (htab->n_elements * 2 > htab->size)
+    nsize = _dl_higher_prime_number (htab->n_elements * 2);
+  else
+    nsize = htab->size;
+
+  nentries = calloc (sizeof (void *), nsize);
+  if (nentries == NULL)
+    return 0;
+  htab->entries = nentries;
+  htab->size = nsize;
+
+  p = oentries;
+  do
+    {
+      if (*p)
+	*find_empty_slot_for_expand (htab, hash_fn (*p))
+	  = *p;
+
+      p++;
+    }
+  while (p < olimit);
+
+  /* Without recording the free corresponding to the malloc used to
+     allocate the table, we couldn't tell whether this was allocated
+     by the malloc() built into ld.so or the one in the main
+     executable or libc.  Calling free() for something that was
+     allocated by the early malloc(), rather than the final run-time
+     malloc() could do Very Bad Things (TM).  We will waste memory
+     allocated early as long as there's no corresponding free(), but
+     this isn't so much memory as to be significant.  */
+
+  if (htab->free)
+    htab->free (oentries);
+
+  /* Use the free() corresponding to the malloc() above to free this
+     up.  */
+  htab->free = free;
+
+  return 1;
+}
+
+/* This function searches for a hash table slot containing an entry
+   equal to the given element.  To delete an entry, call this with
+   INSERT = 0, then call htab_clear_slot on the slot returned (possibly
+   after doing some checks).  To insert an entry, call this with
+   INSERT = 1, then write the value you want into the returned slot.
+   When inserting an entry, NULL may be returned if memory allocation
+   fails.  */
+
+inline static void **
+htab_find_slot (struct hashtab *htab, void *ptr, int insert,
+		int (*hash_fn)(void *), int (*eq_fn)(void *, void *))
+{
+  unsigned int index;
+  int hash, hash2;
+  size_t size;
+  void **entry;
+
+  if (htab->size * 3 <= htab->n_elements * 4
+      && htab_expand (htab, hash_fn) == 0)
+    return NULL;
+
+  hash = hash_fn (ptr);
+
+  size = htab->size;
+  index = hash % size;
+
+  entry = &htab->entries[index];
+  if (!*entry)
+    goto empty_entry;
+  else if (eq_fn (*entry, ptr))
+    return entry;
+
+  hash2 = 1 + hash % (size - 2);
+  for (;;)
+    {
+      index += hash2;
+      if (index >= size)
+	index -= size;
+
+      entry = &htab->entries[index];
+      if (!*entry)
+	goto empty_entry;
+      else if (eq_fn (*entry, ptr))
+	return entry;
+    }
+
+ empty_entry:
+  if (!insert)
+    return NULL;
+
+  htab->n_elements++;
+  return entry;
+}
+
+#endif /* INLINE_HASHTAB_H */