Initial revision

1 files changed, 1028 insertions, 0 deletions

diff --git a/gas/hash.c b/gas/hash.c
new file mode 100644
index 0000000000..dccd660754
--- /dev/null
+++ b/gas/hash.c
@@ -0,0 +1,1028 @@
+/* hash.c - hash table lookup strings -
+   Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 96, 1998
+   Free Software Foundation, Inc.
+
+   This file is part of GAS, the GNU Assembler.
+
+   GAS is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   GAS 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GAS; see the file COPYING.  If not, write to
+   the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/*
+ * BUGS, GRIPES, APOLOGIA etc.
+ *
+ * A typical user doesn't need ALL this: I intend to make a library out
+ * of it one day - Dean Elsner.
+ * Also, I want to change the definition of a symbol to (address,length)
+ * so I can put arbitrary binary in the names stored. [see hsh.c for that]
+ *
+ * This slime is common coupled inside the module. Com-coupling (and other
+ * vandalism) was done to speed running time. The interfaces at the
+ * module's edges are adequately clean.
+ *
+ * There is no way to (a) run a test script through this heap and (b)
+ * compare results with previous scripts, to see if we have broken any
+ * code. Use GNU (f)utilities to do this. A few commands assist test.
+ * The testing is awkward: it tries to be both batch & interactive.
+ * For now, interactive rules!
+ */
+
+/*
+ *  The idea is to implement a symbol table. A test jig is here.
+ *  Symbols are arbitrary strings; they can't contain '\0'.
+ *	[See hsh.c for a more general symbol flavour.]
+ *  Each symbol is associated with a char*, which can point to anything
+ *  you want, allowing an arbitrary property list for each symbol.
+ *
+ *  The basic operations are:
+ *
+ *    new                     creates symbol table, returns handle
+ *    find (symbol)           returns char*
+ *    insert (symbol,char*)   error if symbol already in table
+ *    delete (symbol)         returns char* if symbol was in table
+ *    apply                   so you can delete all symbols before die()
+ *    die                     destroy symbol table (free up memory)
+ *
+ *  Supplementary functions include:
+ *
+ *    say                     how big? what % full?
+ *    replace (symbol,newval) report previous value
+ *    jam (symbol,value)      assert symbol:=value
+ *
+ *  You, the caller, have control over errors: this just reports them.
+ *
+ *  This package requires malloc(), free().
+ *  Malloc(size) returns NULL or address of char[size].
+ *  Free(address) frees same.
+ */
+
+/*
+ *  The code and its structures are re-enterent.
+ *
+ *  Before you do anything else, you must call hash_new() which will
+ *  return the address of a hash-table-control-block.  You then use
+ *  this address as a handle of the symbol table by passing it to all
+ *  the other hash_...() functions.  The only approved way to recover
+ *  the memory used by the symbol table is to call hash_die() with the
+ *  handle of the symbol table.
+ *
+ *  Before you call hash_die() you normally delete anything pointed to
+ *  by individual symbols. After hash_die() you can't use that symbol
+ *  table again.
+ *
+ *  The char* you associate with a symbol may not be NULL (0) because
+ *  NULL is returned whenever a symbol is not in the table. Any other
+ *  value is OK, except DELETED, #defined below.
+ *
+ *  When you supply a symbol string for insertion, YOU MUST PRESERVE THE
+ *  STRING until that symbol is deleted from the table. The reason is that
+ *  only the address you supply, NOT the symbol string itself, is stored
+ *  in the symbol table.
+ *
+ *  You may delete and add symbols arbitrarily.
+ *  Any or all symbols may have the same 'value' (char *). In fact, these
+ *  routines don't do anything with your symbol values.
+ *
+ *  You have no right to know where the symbol:char* mapping is stored,
+ *  because it moves around in memory; also because we may change how it
+ *  works and we don't want to break your code do we? However the handle
+ *  (address of struct hash_control) is never changed in
+ *  the life of the symbol table.
+ *
+ *  What you CAN find out about a symbol table is:
+ *    how many slots are in the hash table?
+ *    how many slots are filled with symbols?
+ *    (total hashes,collisions) for (reads,writes) (*)
+ *  All of the above values vary in time.
+ *  (*) some of these numbers will not be meaningful if we change the
+ *  internals. */
+
+/*
+ *  I N T E R N A L
+ *
+ *  Hash table is an array of hash_entries; each entry is a pointer to a
+ *  a string and a user-supplied value 1 char* wide.
+ *
+ *  The array always has 2 ** n elements, n>0, n integer.
+ *  There is also a 'wall' entry after the array, which is always empty
+ *  and acts as a sentinel to stop running off the end of the array.
+ *  When the array gets too full, we create a new array twice as large
+ *  and re-hash the symbols into the new array, then forget the old array.
+ *  (Of course, we copy the values into the new array before we junk the
+ *  old array!)
+ *
+ */
+
+#include <stdio.h>
+
+#ifndef FALSE
+#define FALSE	(0)
+#define TRUE	(!FALSE)
+#endif /* no FALSE yet */
+
+#include <ctype.h>
+#define min(a, b)	((a) < (b) ? (a) : (b))
+
+#include "as.h"
+
+#define error	as_fatal
+
+static char _deleted_[1];
+#define DELETED     ((PTR)_deleted_)	/* guarenteed unique address */
+#define START_POWER    (10)	/* power of two: size of new hash table */
+
+/* TRUE if a symbol is in entry @ ptr.  */
+#define islive(ptr) (ptr->hash_string && ptr->hash_string!=DELETED)
+
+enum stat_enum {
+  /* Number of slots in hash table.  The wall does not count here.
+     We expect this is always a power of 2.  */
+  STAT_SIZE = 0,
+  /* Number of hash_ask calls.  */
+  STAT_ACCESS,
+  STAT_ACCESS_w,
+  /* Number of collisions (total).  This may exceed STAT_ACCESS if we
+     have lots of collisions/access.  */
+  STAT_COLLIDE,
+  STAT_COLLIDE_w,
+  /* Slots used right now.  */
+  STAT_USED,
+  /* How many string compares?  */
+  STAT_STRCMP,
+  STAT_STRCMP_w,
+  /* Size of statistics block... this must be last.  */
+  STATLENGTH
+};
+#define STAT__READ     (0)	/* reading */
+#define STAT__WRITE    (1)	/* writing */
+
+/* When we grow a hash table, by what power of two do we increase it?  */
+#define GROW_FACTOR 1
+/* When should we grow it?  */
+#define FULL_VALUE(N)	((N) / 2)
+
+/* #define SUSPECT to do runtime checks */
+/* #define TEST to be a test jig for hash...() */
+
+#ifdef TEST
+/* TEST: use smaller hash table */
+#undef  START_POWER
+#define START_POWER (3)
+#undef  START_SIZE
+#define START_SIZE  (8)
+#undef  START_FULL
+#define START_FULL  (4)
+#endif
+
+struct hash_entry
+{
+  const char *hash_string;	/* points to where the symbol string is */
+  /* NULL means slot is not used */
+  /* DELETED means slot was deleted */
+  PTR hash_value;		/* user's datum, associated with symbol */
+  unsigned long h;
+};
+
+struct hash_control {
+  struct hash_entry *hash_where;/* address of hash table */
+  int hash_sizelog;		/* Log of ( hash_mask + 1 ) */
+  int hash_mask;		/* masks a hash into index into table */
+  int hash_full;		/* when hash_stat[STAT_USED] exceeds this, */
+  /* grow table */
+  struct hash_entry *hash_wall;	/* point just after last (usable) entry */
+  /* here we have some statistics */
+  int hash_stat[STATLENGTH];	/* lies & statistics */
+};
+
+/*------------------ plan ---------------------------------- i = internal
+
+  struct hash_control * c;
+  struct hash_entry   * e;                                                    i
+  int                   b[z];     buffer for statistics
+  z         size of b
+  char                * s;        symbol string (address) [ key ]
+  char                * v;        value string (address)  [datum]
+  boolean               f;        TRUE if we found s in hash table            i
+  char                * t;        error string; 0 means OK
+  int                   a;        access type [0...n)                         i
+
+  c=hash_new       ()             create new hash_control
+
+  hash_die         (c)            destroy hash_control (and hash table)
+  table should be empty.
+  doesn't check if table is empty.
+  c has no meaning after this.
+
+  hash_say         (c,b,z)        report statistics of hash_control.
+  also report number of available statistics.
+
+  v=hash_delete    (c,s)          delete symbol, return old value if any.
+  ask()                       NULL means no old value.
+  f
+
+  v=hash_replace   (c,s,v)        replace old value of s with v.
+  ask()                       NULL means no old value: no table change.
+  f
+
+  t=hash_insert    (c,s,v)        insert (s,v) in c.
+  ask()                       return error string.
+  f                           it is an error to insert if s is already
+  in table.
+  if any error, c is unchanged.
+
+  t=hash_jam       (c,s,v)        assert that new value of s will be v.       i
+  ask()                       it may decide to GROW the table.            i
+  f                                                                       i
+  grow()                                                                  i
+  t=hash_grow      (c)            grow the hash table.                        i
+  jam()                       will invoke JAM.                            i
+
+  ?=hash_apply     (c,y)          apply y() to every symbol in c.
+  y                           evtries visited in 'unspecified' order.
+
+  v=hash_find      (c,s)          return value of s, or NULL if s not in c.
+  ask()
+  f
+
+  f,e=hash_ask()   (c,s,a)        return slot where s SHOULD live.            i
+  code()                      maintain collision stats in c.              i
+
+  .=hash_code      (c,s)          compute hash-code for s,                    i
+  from parameters of c.                       i
+
+  */
+
+/* Returned by hash_ask() to stop extra testing. hash_ask() wants to
+   return both a slot and a status. This is the status.  TRUE: found
+   symbol FALSE: absent: empty or deleted slot Also returned by
+   hash_jam().  TRUE: we replaced a value FALSE: we inserted a value.  */
+static char hash_found;
+
+static struct hash_entry *hash_ask PARAMS ((struct hash_control *,
+					    const char *, int));
+static int hash_code PARAMS ((struct hash_control *, const char *));
+static const char *hash_grow PARAMS ((struct hash_control *));
+
+/* Create a new hash table.  Return NULL if failed; otherwise return handle
+   (address of struct hash).  */
+struct hash_control *
+hash_new ()
+{
+  struct hash_control *retval;
+  struct hash_entry *room;	/* points to hash table */
+  struct hash_entry *wall;
+  struct hash_entry *entry;
+  int *ip;		/* scan stats block of struct hash_control */
+  int *nd;		/* limit of stats block */
+
+  room = (struct hash_entry *) xmalloc (sizeof (struct hash_entry)
+					/* +1 for the wall entry */
+					* ((1 << START_POWER) + 1));
+  retval = (struct hash_control *) xmalloc (sizeof (struct hash_control));
+
+  nd = retval->hash_stat + STATLENGTH;
+  for (ip = retval->hash_stat; ip < nd; ip++)
+    *ip = 0;
+
+  retval->hash_stat[STAT_SIZE] = 1 << START_POWER;
+  retval->hash_mask = (1 << START_POWER) - 1;
+  retval->hash_sizelog = START_POWER;
+  /* works for 1's compl ok */
+  retval->hash_where = room;
+  retval->hash_wall =
+    wall = room + (1 << START_POWER);
+  retval->hash_full = FULL_VALUE (1 << START_POWER);
+  for (entry = room; entry <= wall; entry++)
+    entry->hash_string = NULL;
+  return retval;
+}
+
+/*
+ *           h a s h _ d i e ( )
+ *
+ * Table should be empty, but this is not checked.
+ * To empty the table, try hash_apply()ing a symbol deleter.
+ * Return to free memory both the hash table and it's control
+ * block.
+ * 'handle' has no meaning after this function.
+ * No errors are recoverable.
+ */
+void
+hash_die (handle)
+     struct hash_control *handle;
+{
+  free ((char *) handle->hash_where);
+  free ((char *) handle);
+}
+
+#ifdef TEST
+/*
+ *           h a s h _ s a y ( )
+ *
+ * Return the size of the statistics table, and as many statistics as
+ * we can until either (a) we have run out of statistics or (b) caller
+ * has run out of buffer.
+ * NOTE: hash_say treats all statistics alike.
+ * These numbers may change with time, due to insertions, deletions
+ * and expansions of the table.
+ * The first "statistic" returned is the length of hash_stat[].
+ * Then contents of hash_stat[] are read out (in ascending order)
+ * until your buffer or hash_stat[] is exausted.
+ */
+static void
+hash_say (handle, buffer, bufsiz)
+     struct hash_control *handle;
+     int buffer[ /*bufsiz*/ ];
+     int bufsiz;
+{
+  int *nd;		/* limit of statistics block */
+  int *ip;		/* scan statistics */
+
+  ip = handle->hash_stat;
+  nd = ip + min (bufsiz - 1, STATLENGTH);
+  if (bufsiz > 0)		/* trust nothing! bufsiz<=0 is dangerous */
+    {
+      *buffer++ = STATLENGTH;
+      for (; ip < nd; ip++, buffer++)
+	{
+	  *buffer = *ip;
+	}
+    }
+}
+#endif
+
+/*
+ *           h a s h _ d e l e t e ( )
+ *
+ * Try to delete a symbol from the table.
+ * If it was there, return its value (and adjust STAT_USED).
+ * Otherwise, return NULL.
+ * Anyway, the symbol is not present after this function.
+ *
+ */
+PTR				/* NULL if string not in table, else */
+/* returns value of deleted symbol */
+hash_delete (handle, string)
+     struct hash_control *handle;
+     const char *string;
+{
+  PTR retval;
+  struct hash_entry *entry;
+
+  entry = hash_ask (handle, string, STAT__WRITE);
+  if (hash_found)
+    {
+      retval = entry->hash_value;
+      entry->hash_string = DELETED;
+      handle->hash_stat[STAT_USED] -= 1;
+#ifdef SUSPECT
+      if (handle->hash_stat[STAT_USED] < 0)
+	{
+	  error ("hash_delete");
+	}
+#endif /* def SUSPECT */
+    }
+  else
+    {
+      retval = NULL;
+    }
+  return (retval);
+}
+
+/*
+ *                   h a s h _ r e p l a c e ( )
+ *
+ * Try to replace the old value of a symbol with a new value.
+ * Normally return the old value.
+ * Return NULL and don't change the table if the symbol is not already
+ * in the table.
+ */
+PTR
+hash_replace (handle, string, value)
+     struct hash_control *handle;
+     const char *string;
+     PTR value;
+{
+  struct hash_entry *entry;
+  char *retval;
+
+  entry = hash_ask (handle, string, STAT__WRITE);
+  if (hash_found)
+    {
+      retval = entry->hash_value;
+      entry->hash_value = value;
+    }
+  else
+    {
+      retval = NULL;
+    }
+  ;
+  return retval;
+}
+
+/*
+ *                   h a s h _ i n s e r t ( )
+ *
+ * Insert a (symbol-string, value) into the hash table.
+ * Return an error string, 0 means OK.
+ * It is an 'error' to insert an existing symbol.
+ */
+
+const char *			/* return error string */
+hash_insert (handle, string, value)
+     struct hash_control *handle;
+     const char *string;
+     PTR value;
+{
+  struct hash_entry *entry;
+  const char *retval;
+
+  retval = 0;
+  if (handle->hash_stat[STAT_USED] > handle->hash_full)
+    {
+      retval = hash_grow (handle);
+    }
+  if (!retval)
+    {
+      entry = hash_ask (handle, string, STAT__WRITE);
+      if (hash_found)
+	{
+	  retval = "exists";
+	}
+      else
+	{
+	  entry->hash_value = value;
+	  entry->hash_string = string;
+	  handle->hash_stat[STAT_USED] += 1;
+	}
+    }
+  return retval;
+}
+
+/*
+ *               h a s h _ j a m ( )
+ *
+ * Regardless of what was in the symbol table before, after hash_jam()
+ * the named symbol has the given value. The symbol is either inserted or
+ * (its value is) replaced.
+ * An error message string is returned, 0 means OK.
+ *
+ * WARNING: this may decide to grow the hashed symbol table.
+ * To do this, we call hash_grow(), WHICH WILL recursively CALL US.
+ *
+ * We report status internally: hash_found is TRUE if we replaced, but
+ * false if we inserted.
+ */
+const char *
+hash_jam (handle, string, value)
+     struct hash_control *handle;
+     const char *string;
+     PTR value;
+{
+  const char *retval;
+  struct hash_entry *entry;
+
+  retval = 0;
+  if (handle->hash_stat[STAT_USED] > handle->hash_full)
+    {
+      retval = hash_grow (handle);
+    }
+  if (!retval)
+    {
+      entry = hash_ask (handle, string, STAT__WRITE);
+      if (!hash_found)
+	{
+	  entry->hash_string = string;
+	  handle->hash_stat[STAT_USED] += 1;
+	}
+      entry->hash_value = value;
+    }
+  return retval;
+}
+
+/*
+ *               h a s h _ g r o w ( )
+ *
+ * Grow a new (bigger) hash table from the old one.
+ * We choose to double the hash table's size.
+ * Return a human-scrutible error string: 0 if OK.
+ * Warning! This uses hash_jam(), which had better not recurse
+ * back here! Hash_jam() conditionally calls us, but we ALWAYS
+ * call hash_jam()!
+ * Internal.
+ */
+static const char *
+hash_grow (handle)		/* make a hash table grow */
+     struct hash_control *handle;
+{
+  struct hash_entry *newwall;
+  struct hash_entry *newwhere;
+  struct hash_entry *newtrack;
+  struct hash_entry *oldtrack;
+  struct hash_entry *oldwhere;
+  struct hash_entry *oldwall;
+  int temp;
+  int newsize;
+  const char *string;
+  const char *retval;
+#ifdef SUSPECT
+  int oldused;
+#endif
+
+  /*
+   * capture info about old hash table
+   */
+  oldwhere = handle->hash_where;
+  oldwall = handle->hash_wall;
+#ifdef SUSPECT
+  oldused = handle->hash_stat[STAT_USED];
+#endif
+  /*
+   * attempt to get enough room for a hash table twice as big
+   */
+  temp = handle->hash_stat[STAT_SIZE];
+  newwhere = ((struct hash_entry *)
+	      xmalloc ((unsigned long) ((temp << (GROW_FACTOR + 1))
+					/* +1 for wall slot */
+					* sizeof (struct hash_entry))));
+  if (newwhere == NULL)
+    return "no_room";
+
+  /*
+   * have enough room: now we do all the work.
+   * double the size of everything in handle.
+   */
+  handle->hash_mask = ((handle->hash_mask + 1) << GROW_FACTOR) - 1;
+  handle->hash_stat[STAT_SIZE] <<= GROW_FACTOR;
+  newsize = handle->hash_stat[STAT_SIZE];
+  handle->hash_where = newwhere;
+  handle->hash_full <<= GROW_FACTOR;
+  handle->hash_sizelog += GROW_FACTOR;
+  handle->hash_wall = newwall = newwhere + newsize;
+  /* Set all those pesky new slots to vacant.  */
+  for (newtrack = newwhere; newtrack <= newwall; newtrack++)
+    newtrack->hash_string = NULL;
+  /* We will do a scan of the old table, the hard way, using the
+   * new control block to re-insert the data into new hash table.  */
+  handle->hash_stat[STAT_USED] = 0;
+  for (oldtrack = oldwhere; oldtrack < oldwall; oldtrack++)
+    if (((string = oldtrack->hash_string) != NULL) && string != DELETED)
+      if ((retval = hash_jam (handle, string, oldtrack->hash_value)))
+	return retval;
+
+#ifdef SUSPECT
+  if (handle->hash_stat[STAT_USED] != oldused)
+    return "hash_used";
+#endif
+
+  /* We have a completely faked up control block.
+     Return the old hash table.  */
+  free ((char *) oldwhere);
+
+  return 0;
+}
+
+#ifdef TEST
+/*
+ *          h a s h _ a p p l y ( )
+ *
+ * Use this to scan each entry in symbol table.
+ * For each symbol, this calls (applys) a nominated function supplying the
+ * symbol's value (and the symbol's name).
+ * The idea is you use this to destroy whatever is associted with
+ * any values in the table BEFORE you destroy the table with hash_die.
+ * Of course, you can use it for other jobs; whenever you need to
+ * visit all extant symbols in the table.
+ *
+ * We choose to have a call-you-back idea for two reasons:
+ *  asthetic: it is a neater idea to use apply than an explicit loop
+ *  sensible: if we ever had to grow the symbol table (due to insertions)
+ *            then we would lose our place in the table when we re-hashed
+ *            symbols into the new table in a different order.
+ *
+ * The order symbols are visited depends entirely on the hashing function.
+ * Whenever you insert a (symbol, value) you risk expanding the table. If
+ * you do expand the table, then the hashing function WILL change, so you
+ * MIGHT get a different order of symbols visited. In other words, if you
+ * want the same order of visiting symbols as the last time you used
+ * hash_apply() then you better not have done any hash_insert()s or
+ * hash_jam()s since the last time you used hash_apply().
+ *
+ * In future we may use the value returned by your nominated function.
+ * One idea is to abort the scan if, after applying the function to a
+ * certain node, the function returns a certain code.
+ *
+ * The function you supply should be of the form:
+ *      void myfunct(string,value)
+ *              char * string;        |* the symbol's name *|
+ *              char * value;         |* the symbol's value *|
+ *      {
+ *        |* ... *|
+ *      }
+ *
+ */
+void
+hash_apply (handle, function)
+     struct hash_control *handle;
+     void (*function) ();
+{
+  struct hash_entry *entry;
+  struct hash_entry *wall;
+
+  wall = handle->hash_wall;
+  for (entry = handle->hash_where; entry < wall; entry++)
+    {
+      if (islive (entry))	/* silly code: tests entry->string twice! */
+	{
+	  (*function) (entry->hash_string, entry->hash_value);
+	}
+    }
+}
+#endif
+
+/*
+ *          h a s h _ f i n d ( )
+ *
+ * Given symbol string, find value (if any).
+ * Return found value or NULL.
+ */
+PTR
+hash_find (handle, string)
+     struct hash_control *handle;
+     const char *string;
+{
+  struct hash_entry *entry;
+
+  entry = hash_ask (handle, string, STAT__READ);
+  if (hash_found)
+    return entry->hash_value;
+  else
+    return NULL;
+}
+
+/*
+ *          h a s h _ a s k ( )
+ *
+ * Searches for given symbol string.
+ * Return the slot where it OUGHT to live. It may be there.
+ * Return hash_found: TRUE only if symbol is in that slot.
+ * Access argument is to help keep statistics in control block.
+ * Internal.
+ */
+static struct hash_entry *	/* string slot, may be empty or deleted */
+hash_ask (handle, string, access_type)
+     struct hash_control *handle;
+     const char *string;
+     int access_type;
+{
+  const char *s;
+  struct hash_entry *slot;
+  int collision;	/* count collisions */
+  int strcmps;
+  int hcode;
+
+  /* start looking here */
+  hcode = hash_code (handle, string);
+  slot = handle->hash_where + (hcode & handle->hash_mask);
+
+  handle->hash_stat[STAT_ACCESS + access_type] += 1;
+  collision = strcmps = 0;
+  hash_found = FALSE;
+  while (((s = slot->hash_string) != NULL) && s != DELETED)
+    {
+      if (string == s)
+	{
+	  hash_found = TRUE;
+	  break;
+	}
+      if (slot->h == (unsigned long) hcode)
+	{
+	  if (!strcmp (string, s))
+	    {
+	      hash_found = TRUE;
+	      break;
+	    }
+	  strcmps++;
+	}
+      collision++;
+      slot++;
+    }
+  /*
+   * slot:                                                      return:
+   *       in use:     we found string                           slot
+   *       at empty:
+   *                   at wall:        we fell off: wrap round   ????
+   *                   in table:       dig here                  slot
+   *       at DELETED: dig here                                  slot
+   */
+  if (slot == handle->hash_wall)
+    {
+      slot = handle->hash_where;/* now look again */
+      while (((s = slot->hash_string) != NULL) && s != DELETED)
+	{
+	  if (string == s)
+	    {
+	      hash_found = TRUE;
+	      break;
+	    }
+	  if (slot->h == (unsigned long) hcode)
+	    {
+	      if (!strcmp (string, s))
+		{
+		  hash_found = TRUE;
+		  break;
+		}
+	      strcmps++;
+	    }
+	  collision++;
+	  slot++;
+	}
+      /*
+       * slot:                                                   return:
+       *       in use: we found it                                slot
+       *       empty:  wall:         ERROR IMPOSSIBLE             !!!!
+       *               in table:     dig here                     slot
+       *       DELETED:dig here                                   slot
+       */
+    }
+  handle->hash_stat[STAT_COLLIDE + access_type] += collision;
+  handle->hash_stat[STAT_STRCMP + access_type] += strcmps;
+  if (!hash_found)
+    slot->h = hcode;
+  return slot;			/* also return hash_found */
+}
+
+/*
+ *           h a s h _ c o d e
+ *
+ * Does hashing of symbol string to hash number.
+ * Internal.
+ */
+static int
+hash_code (handle, string)
+     struct hash_control *handle;
+     const char *string;
+{
+#if 1 /* There seems to be some interesting property of this function
+	 that prevents the bfd version below from being an adequate
+	 substitute.  @@ Figure out what this property is!  */
+  long h;		/* hash code built here */
+  long c;		/* each character lands here */
+  int n;		/* Amount to shift h by */
+
+  n = (handle->hash_sizelog - 3);
+  h = 0;
+  while ((c = *string++) != 0)
+    {
+      h += c;
+      h = (h << 3) + (h >> n) + c;
+    }
+  return h;
+#else
+  /* from bfd */
+  unsigned long h = 0;
+  unsigned int len = 0;
+  unsigned int c;
+
+  while ((c = *string++) != 0)
+    {
+      h += c + (c << 17);
+      h ^= h >> 2;
+      ++len;
+    }
+  h += len + (len << 17);
+  h ^= h >> 2;
+  return h;
+#endif
+}
+
+void
+hash_print_statistics (file, name, h)
+     FILE *file;
+     const char *name;
+     struct hash_control *h;
+{
+  unsigned long sz, used, pct;
+
+  if (h == 0)
+    return;
+
+  sz = h->hash_stat[STAT_SIZE];
+  used = h->hash_stat[STAT_USED];
+  pct = (used * 100 + sz / 2) / sz;
+
+  fprintf (file, "%s hash statistics:\n\t%lu/%lu slots used (%lu%%)\n",
+	   name, used, sz, pct);
+
+#define P(name, off)							\
+  fprintf (file, "\t%-16s %6dr + %6dw = %7d\n", name,			\
+	   h->hash_stat[off+STAT__READ],				\
+	   h->hash_stat[off+STAT__WRITE],				\
+	   h->hash_stat[off+STAT__READ] + h->hash_stat[off+STAT__WRITE])
+
+  P ("accesses:", STAT_ACCESS);
+  P ("collisions:", STAT_COLLIDE);
+  P ("string compares:", STAT_STRCMP);
+
+#undef P
+}
+
+/*
+ * Here is a test program to exercise above.
+ */
+#ifdef TEST
+
+#define TABLES (6)		/* number of hash tables to maintain */
+/* (at once) in any testing */
+#define STATBUFSIZE (12)	/* we can have 12 statistics */
+
+int statbuf[STATBUFSIZE];	/* display statistics here */
+char answer[100];		/* human farts here */
+char *hashtable[TABLES];	/* we test many hash tables at once */
+char *h;			/* points to curent hash_control */
+char **pp;
+char *p;
+char *name;
+char *value;
+int size;
+int used;
+char command;
+int number;			/* number 0:TABLES-1 of current hashed */
+/* symbol table */
+
+main ()
+{
+  void applicatee ();
+  void destroy ();
+  char *what ();
+  int *ip;
+
+  number = 0;
+  h = 0;
+  printf ("type h <RETURN> for help\n");
+  for (;;)
+    {
+      printf ("hash_test command: ");
+      gets (answer);
+      command = answer[0];
+      if (isupper (command))
+	command = tolower (command);	/* ecch! */
+      switch (command)
+	{
+	case '#':
+	  printf ("old hash table #=%d.\n", number);
+	  whattable ();
+	  break;
+	case '?':
+	  for (pp = hashtable; pp < hashtable + TABLES; pp++)
+	    {
+	      printf ("address of hash table #%d control block is %xx\n"
+		      ,pp - hashtable, *pp);
+	    }
+	  break;
+	case 'a':
+	  hash_apply (h, applicatee);
+	  break;
+	case 'd':
+	  hash_apply (h, destroy);
+	  hash_die (h);
+	  break;
+	case 'f':
+	  p = hash_find (h, name = what ("symbol"));
+	  printf ("value of \"%s\" is \"%s\"\n", name, p ? p : "NOT-PRESENT");
+	  break;
+	case 'h':
+	  printf ("# show old, select new default hash table number\n");
+	  printf ("? display all hashtable control block addresses\n");
+	  printf ("a apply a simple display-er to each symbol in table\n");
+	  printf ("d die: destroy hashtable\n");
+	  printf ("f find value of nominated symbol\n");
+	  printf ("h this help\n");
+	  printf ("i insert value into symbol\n");
+	  printf ("j jam value into symbol\n");
+	  printf ("n new hashtable\n");
+	  printf ("r replace a value with another\n");
+	  printf ("s say what %% of table is used\n");
+	  printf ("q exit this program\n");
+	  printf ("x delete a symbol from table, report its value\n");
+	  break;
+	case 'i':
+	  p = hash_insert (h, name = what ("symbol"), value = what ("value"));
+	  if (p)
+	    {
+	      printf ("symbol=\"%s\"  value=\"%s\"  error=%s\n", name, value,
+		      p);
+	    }
+	  break;
+	case 'j':
+	  p = hash_jam (h, name = what ("symbol"), value = what ("value"));
+	  if (p)
+	    {
+	      printf ("symbol=\"%s\"  value=\"%s\"  error=%s\n", name, value, p);
+	    }
+	  break;
+	case 'n':
+	  h = hashtable[number] = (char *) hash_new ();
+	  break;
+	case 'q':
+	  exit (EXIT_SUCCESS);
+	case 'r':
+	  p = hash_replace (h, name = what ("symbol"), value = what ("value"));
+	  printf ("old value was \"%s\"\n", p ? p : "{}");
+	  break;
+	case 's':
+	  hash_say (h, statbuf, STATBUFSIZE);
+	  for (ip = statbuf; ip < statbuf + STATBUFSIZE; ip++)
+	    {
+	      printf ("%d ", *ip);
+	    }
+	  printf ("\n");
+	  break;
+	case 'x':
+	  p = hash_delete (h, name = what ("symbol"));
+	  printf ("old value was \"%s\"\n", p ? p : "{}");
+	  break;
+	default:
+	  printf ("I can't understand command \"%c\"\n", command);
+	  break;
+	}
+    }
+}
+
+char *
+what (description)
+     char *description;
+{
+  char *retval;
+  char *malloc ();
+
+  printf ("   %s : ", description);
+  gets (answer);
+  /* will one day clean up answer here */
+  retval = malloc (strlen (answer) + 1);
+  if (!retval)
+    {
+      error ("room");
+    }
+  (void) strcpy (retval, answer);
+  return (retval);
+}
+
+void
+destroy (string, value)
+     char *string;
+     char *value;
+{
+  free (string);
+  free (value);
+}
+
+
+void
+applicatee (string, value)
+     char *string;
+     char *value;
+{
+  printf ("%.20s-%.20s\n", string, value);
+}
+
+whattable ()			/* determine number: what hash table to use */
+     /* also determine h: points to hash_control */
+{
+
+  for (;;)
+    {
+      printf ("   what hash table (%d:%d) ?  ", 0, TABLES - 1);
+      gets (answer);
+      sscanf (answer, "%d", &number);
+      if (number >= 0 && number < TABLES)
+	{
+	  h = hashtable[number];
+	  if (!h)
+	    {
+	      printf ("warning: current hash-table-#%d. has no hash-control\n", number);
+	    }
+	  return;
+	}
+      else
+	{
+	  printf ("invalid hash table number: %d\n", number);
+	}
+    }
+}
+
+
+
+#endif /* #ifdef TEST */
+
+/* end of hash.c */