Version 2.0.

[bison.git] / src / symtab.c

diff --git a/src/symtab.c b/src/symtab.c
index 1bc2c3779ca727362f3d63986074b2f5d53c5cad..63f3bf3913c2c597088b247d135419a4cdf5ef27 100644 (file)
--- a/src/symtab.c
+++ b/src/symtab.c
@@ -1,145 +1,628 @@
-/* Symbol table manager for Bison,
-   Copyright (C) 1984, 1989 Free Software Foundation, Inc.
+/* Symbol table manager for Bison.

 
 

-This file is part of Bison, the GNU Compiler Compiler.
+   Copyright (C) 1984, 1989, 2000, 2001, 2002, 2004 Free Software
+   Foundation, Inc.

 
 

-Bison 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.
+   This file is part of Bison, the GNU Compiler Compiler.

 
 

-Bison 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.
+   Bison 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.

 
 

-You should have received a copy of the GNU General Public License
-along with Bison; see the file COPYING.  If not, write to
-the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.  */
+   Bison 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 Bison; see the file COPYING.  If not, write to
+   the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */

 
 
 #include "system.h"
 
 
 #include "system.h"

-#include "xalloc.h"
-#include "symtab.h"
+
+#include <hash.h>
+#include <quotearg.h>
+
+#include "complain.h"

 #include "gram.h"
 #include "gram.h"

+#include "symtab.h"
+
+/*------------------------.
+| Distinguished symbols.  |
+`------------------------*/

 
 

+symbol *errtoken = NULL;
+symbol *undeftoken = NULL;
+symbol *endtoken = NULL;
+symbol *accept = NULL;
+symbol *startsymbol = NULL;
+location startsymbol_location;

 
 

-bucket *firstsymbol;
-static bucket *lastsymbol;
-static bucket **symtab;
+/*---------------------------------.
+| Create a new symbol, named TAG.  |
+`---------------------------------*/

 
 

-static int
-hash (const char *key)
+static symbol *
+symbol_new (uniqstr tag, location loc)

 {
 {

-  register const char *cp;
-  register int k;
+  symbol *res = xmalloc (sizeof *res);
+
+  uniqstr_assert (tag);
+  res->tag = tag;
+  res->location = loc;
+
+  res->type_name = NULL;
+  res->destructor = NULL;
+  res->printer = NULL;
+
+  res->number = NUMBER_UNDEFINED;
+  res->prec = 0;
+  res->assoc = undef_assoc;
+  res->user_token_number = USER_NUMBER_UNDEFINED;
+
+  res->alias = NULL;
+  res->class = unknown_sym;
+
+  if (nsyms == SYMBOL_NUMBER_MAXIMUM)
+    fatal (_("too many symbols in input grammar (limit is %d)"),
+          SYMBOL_NUMBER_MAXIMUM);
+  nsyms++;
+  return res;
+}

 
 

-  cp = key;
-  k = 0;
-  while (*cp)
-    k = ((k << 1) ^ (*cp++)) & 0x3fff;

 
 

-  return k % TABSIZE;
+/*------------------------------------------------------------------.
+| Complain that S's WHAT is redeclared at SECOND, and was first set |
+| at FIRST.                                                         |
+`------------------------------------------------------------------*/
+
+static void
+redeclaration (symbol* s, const char *what, location first, location second)
+{
+  complain_at (second, _("%s redeclaration for %s"), what, s->tag);
+  complain_at (first, _("first declaration"));
+}
+
+
+/*-----------------------------------------------------------------.
+| Set the TYPE_NAME associated with SYM.  Does nothing if passed 0 |
+| as TYPE_NAME.                                                    |
+`-----------------------------------------------------------------*/
+
+void
+symbol_type_set (symbol *sym, uniqstr type_name, location loc)
+{
+  if (type_name)
+    {
+      if (sym->type_name)
+       redeclaration (sym, "%type", sym->type_location, loc);
+      uniqstr_assert (type_name);
+      sym->type_name = type_name;
+      sym->type_location = loc;
+    }
+}
+
+
+/*------------------------------------------------------------------.
+| Set the DESTRUCTOR associated with SYM.  Do nothing if passed 0.  |
+`------------------------------------------------------------------*/
+
+void
+symbol_destructor_set (symbol *sym, char *destructor, location loc)
+{
+  if (destructor)
+    {
+      if (sym->destructor)
+       redeclaration (sym, "%destructor", sym->destructor_location, loc);
+      sym->destructor = destructor;
+      sym->destructor_location = loc;
+    }
+}
+
+
+/*---------------------------------------------------------------.
+| Set the PRINTER associated with SYM.  Do nothing if passed 0.  |
+`---------------------------------------------------------------*/
+
+void
+symbol_printer_set (symbol *sym, char *printer, location loc)
+{
+  if (printer)
+    {
+      if (sym->printer)
+       redeclaration (sym, "%printer", sym->destructor_location, loc);
+      sym->printer = printer;
+      sym->printer_location = loc;
+    }
+}
+
+
+/*-----------------------------------------------------------------.
+| Set the PRECEDENCE associated with SYM.  Does nothing if invoked |
+| with UNDEF_ASSOC as ASSOC.                                       |
+`-----------------------------------------------------------------*/
+
+void
+symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
+{
+  if (a != undef_assoc)
+    {
+      if (sym->prec != 0)
+       redeclaration (sym, assoc_to_string (a), sym->prec_location, loc);
+      sym->prec = prec;
+      sym->assoc = a;
+      sym->prec_location = loc;
+    }
+
+  /* Only terminals have a precedence. */
+  symbol_class_set (sym, token_sym, loc);

 }
 
 
 }
 
 

+/*------------------------------------.
+| Set the CLASS associated with SYM.  |
+`------------------------------------*/

 
 

-static char *
-copys (const char *s)
+void
+symbol_class_set (symbol *sym, symbol_class class, location loc)

 {
 {

-  register int i;
-  register const char *cp;
-  register char *result;
+  if (sym->class != unknown_sym && sym->class != class)
+    complain_at (loc, _("symbol %s redefined"), sym->tag);

 
 

-  i = 1;
-  for (cp = s; *cp; cp++)
-    i++;
+  if (class == nterm_sym && sym->class != nterm_sym)
+    sym->number = nvars++;
+  else if (class == token_sym && sym->number == NUMBER_UNDEFINED)
+    sym->number = ntokens++;

 
 

-  result = XMALLOC(char, i);
-  strcpy(result, s);
-  return result;
+  sym->class = class;

 }
 
 
 }
 
 

+/*------------------------------------------------.
+| Set the USER_TOKEN_NUMBER associated with SYM.  |
+`------------------------------------------------*/
+

 void
 void

-tabinit (void)
+symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)

 {
 {

-/*   register int i; JF unused */
+  if (sym->class != token_sym)
+    abort ();

 
 

-  symtab = XCALLOC (bucket *, TABSIZE);
+  if (sym->user_token_number != USER_NUMBER_UNDEFINED
+      && sym->user_token_number != user_token_number)
+    complain_at (loc, _("redefining user token number of %s"), sym->tag);

 
 

-  firstsymbol = NULL;
-  lastsymbol = NULL;
+  sym->user_token_number = user_token_number;
+  /* User defined $end token? */
+  if (user_token_number == 0)
+    {
+      endtoken = sym;
+      endtoken->number = 0;
+      /* It is always mapped to 0, so it was already counted in
+        NTOKENS.  */
+      --ntokens;
+    }

 }
 
 
 }
 
 

-bucket *
-getsym (const char *key)
+/*----------------------------------------------------------.
+| If SYM is not defined, report an error, and consider it a |
+| nonterminal.                                              |
+`----------------------------------------------------------*/
+
+static inline bool
+symbol_check_defined (symbol *sym)

 {
 {

-  register int hashval;
-  register bucket *bp;
-  register int found;
+  if (sym->class == unknown_sym)
+    {
+      complain_at
+       (sym->location,
+        _("symbol %s is used, but is not defined as a token and has no rules"),
+        sym->tag);
+      sym->class = nterm_sym;
+      sym->number = nvars++;
+    }

 
 

-  hashval = hash(key);
-  bp = symtab[hashval];
+  return true;
+}

 
 

-  found = 0;
-  while (bp != NULL && found == 0)
+static bool
+symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
+{
+  return symbol_check_defined (sym);
+}
+
+
+/*------------------------------------------------------------------.
+| Declare the new symbol SYM.  Make it an alias of SYMVAL, and type |
+| SYMVAL with SYM's type.                                           |
+`------------------------------------------------------------------*/
+
+void
+symbol_make_alias (symbol *sym, symbol *symval, location loc)
+{
+  if (symval->alias)
+    warn_at (loc, _("symbol `%s' used more than once as a literal string"),
+            symval->tag);
+  else if (sym->alias)
+    warn_at (loc, _("symbol `%s' given more than one literal string"),
+            sym->tag);
+  else

     {
     {

-      if (strcmp(key, bp->tag) == 0)
-       found = 1;
+      symval->class = token_sym;
+      symval->user_token_number = sym->user_token_number;
+      sym->user_token_number = USER_NUMBER_ALIAS;
+      symval->alias = sym;
+      sym->alias = symval;
+      /* sym and symval combined are only one symbol.  */
+      nsyms--;
+      ntokens--;
+      if (ntokens != sym->number && ntokens != symval->number)
+       abort ();
+      sym->number = symval->number =
+       (symval->number < sym->number) ? symval->number : sym->number;
+    }
+}
+
+
+/*---------------------------------------------------------.
+| Check that THIS, and its alias, have same precedence and |
+| associativity.                                           |
+`---------------------------------------------------------*/
+
+static inline void
+symbol_check_alias_consistency (symbol *this)
+{
+  symbol *alias = this;
+  symbol *orig  = this->alias;
+
+  /* Check only those that _are_ the aliases.  */
+  if (!(this->alias && this->user_token_number == USER_NUMBER_ALIAS))
+    return;
+
+  if (orig->type_name || alias->type_name)
+    {
+      if (orig->type_name)
+       symbol_type_set (alias, orig->type_name, orig->type_location);

       else
       else

-       bp = bp->link;
+       symbol_type_set (orig, alias->type_name, alias->type_location);

     }
 
     }
 

-  if (found == 0)
+
+  if (orig->destructor || alias->destructor)

     {
     {

-      nsyms++;
+      if (orig->destructor)
+       symbol_destructor_set (alias, orig->destructor,
+                              orig->destructor_location);
+      else
+       symbol_destructor_set (orig, alias->destructor,
+                              alias->destructor_location);
+    }

 
 

-      bp = XCALLOC (bucket, 1);
-      bp->link = symtab[hashval];
-      bp->next = NULL;
-      bp->tag = copys(key);
-      bp->class = unknown_sym;
+  if (orig->printer || alias->printer)
+    {
+      if (orig->printer)
+       symbol_printer_set (alias, orig->printer, orig->printer_location);
+      else
+       symbol_printer_set (orig, alias->printer, alias->printer_location);
+    }

 
 

-      if (firstsymbol == NULL)
-       {
-         firstsymbol = bp;
-         lastsymbol = bp;
-       }
+  if (alias->prec || orig->prec)
+    {
+      if (orig->prec)
+       symbol_precedence_set (alias, orig->prec, orig->assoc,
+                              orig->prec_location);

       else
       else

+       symbol_precedence_set (orig, alias->prec, alias->assoc,
+                              alias->prec_location);
+    }
+}
+
+static bool
+symbol_check_alias_consistency_processor (void *this,
+                                         void *null ATTRIBUTE_UNUSED)
+{
+  symbol_check_alias_consistency (this);
+  return true;
+}
+
+
+/*-------------------------------------------------------------------.
+| Assign a symbol number, and write the definition of the token name |
+| into FDEFINES.  Put in SYMBOLS.                                    |
+`-------------------------------------------------------------------*/
+
+static inline bool
+symbol_pack (symbol *this)
+{
+  if (this->class == nterm_sym)
+    {
+      this->number += ntokens;
+    }
+  else if (this->alias)
+    {
+      /* This symbol and its alias are a single token defn.
+        Allocate a tokno, and assign to both check agreement of
+        prec and assoc fields and make both the same */
+      if (this->number == NUMBER_UNDEFINED)

        {
        {

-         lastsymbol->next = bp;
-         lastsymbol = bp;
+         if (this == endtoken || this->alias == endtoken)
+           this->number = this->alias->number = 0;
+         else
+           {
+             if (this->alias->number == NUMBER_UNDEFINED)
+               abort ();
+             this->number = this->alias->number;
+           }

        }
        }

+      /* Do not do processing below for USER_NUMBER_ALIASes.  */
+      if (this->user_token_number == USER_NUMBER_ALIAS)
+       return true;
+    }
+  else /* this->class == token_sym */
+    {
+      if (this->number == NUMBER_UNDEFINED)
+       abort ();
+    }
+
+  symbols[this->number] = this;
+  return true;
+}
+
+static bool
+symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED)
+{
+  return symbol_pack (this);
+}
+
+

 
 

-      symtab[hashval] = bp;
+
+/*--------------------------------------------------.
+| Put THIS in TOKEN_TRANSLATIONS if it is a token.  |
+`--------------------------------------------------*/
+
+static inline bool
+symbol_translation (symbol *this)
+{
+  /* Non-terminal? */
+  if (this->class == token_sym
+      && this->user_token_number != USER_NUMBER_ALIAS)
+    {
+      /* A token which translation has already been set? */
+      if (token_translations[this->user_token_number] != undeftoken->number)
+       complain_at (this->location,
+                    _("tokens %s and %s both assigned number %d"),
+                    symbols[token_translations[this->user_token_number]]->tag,
+                    this->tag, this->user_token_number);
+
+      token_translations[this->user_token_number] = this->number;

     }
 
     }
 

-  return bp;
+  return true;

 }
 
 }
 

+static bool
+symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
+{
+  return symbol_translation (this);
+}
+
+
+/*----------------------.
+| A symbol hash table.  |
+`----------------------*/
+
+/* Initial capacity of symbols hash table.  */
+#define HT_INITIAL_CAPACITY 257
+
+static struct hash_table *symbol_table = NULL;
+
+static inline bool
+hash_compare_symbol (const symbol *m1, const symbol *m2)
+{
+  /* Since tags are unique, we can compare the pointers themselves.  */
+  return UNIQSTR_EQ (m1->tag, m2->tag);
+}
+
+static bool
+hash_symbol_comparator (void const *m1, void const *m2)
+{
+  return hash_compare_symbol (m1, m2);
+}
+
+static inline size_t
+hash_symbol (const symbol *m, size_t tablesize)
+{
+  /* Since tags are unique, we can hash the pointer itself.  */
+  return ((uintptr_t) m->tag) % tablesize;
+}
+
+static size_t
+hash_symbol_hasher (void const *m, size_t tablesize)
+{
+  return hash_symbol (m, tablesize);
+}
+
+
+/*-------------------------------.
+| Create the symbol hash table.  |
+`-------------------------------*/

 
 void
 
 void

-free_symtab (void)
+symbols_new (void)

 {
 {

-  register int i;
-  register bucket *bp,*bptmp;/* JF don't use ptr after free */
+  symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
+                                 NULL,
+                                 hash_symbol_hasher,
+                                 hash_symbol_comparator,
+                                 free);
+}

 
 

-  for (i = 0; i < TABSIZE; i++)
+
+/*----------------------------------------------------------------.
+| Find the symbol named KEY, and return it.  If it does not exist |
+| yet, create it.                                                 |
+`----------------------------------------------------------------*/
+
+symbol *
+symbol_get (const char *key, location loc)
+{
+  symbol probe;
+  symbol *entry;
+
+  /* Keep the symbol in a printable form.  */
+  key = uniqstr_new (quotearg_style (escape_quoting_style, key));
+  probe.tag = key;
+  entry = hash_lookup (symbol_table, &probe);
+
+  if (!entry)

     {
     {

-      bp = symtab[i];
-      while (bp)
+      /* First insertion in the hash. */
+      entry = symbol_new (key, loc);
+      hash_insert (symbol_table, entry);
+    }
+  return entry;
+}
+
+
+/*------------------------------------------------------------------.
+| Generate a dummy nonterminal, whose name cannot conflict with the |
+| user's names.                                                     |
+`------------------------------------------------------------------*/
+
+symbol *
+dummy_symbol_get (location loc)
+{
+  /* Incremented for each generated symbol.  */
+  static int dummy_count = 0;
+  static char buf[256];
+
+  symbol *sym;
+
+  sprintf (buf, "@%d", ++dummy_count);
+  sym = symbol_get (buf, loc);
+  sym->class = nterm_sym;
+  sym->number = nvars++;
+  return sym;
+}
+
+
+/*-------------------.
+| Free the symbols.  |
+`-------------------*/
+
+void
+symbols_free (void)
+{
+  hash_free (symbol_table);
+  free (symbols);
+}
+
+
+/*---------------------------------------------------------------.
+| Look for undefined symbols, report an error, and consider them |
+| terminals.                                                     |
+`---------------------------------------------------------------*/
+
+static void
+symbols_do (Hash_processor processor, void *processor_data)
+{
+  hash_do_for_each (symbol_table, processor, processor_data);
+}
+
+
+/*--------------------------------------------------------------.
+| Check that all the symbols are defined.  Report any undefined |
+| symbols and consider them nonterminals.                       |
+`--------------------------------------------------------------*/
+
+void
+symbols_check_defined (void)
+{
+  symbols_do (symbol_check_defined_processor, NULL);
+}
+
+/*------------------------------------------------------------------.
+| Set TOKEN_TRANSLATIONS.  Check that no two symbols share the same |
+| number.                                                           |
+`------------------------------------------------------------------*/
+
+static void
+symbols_token_translations_init (void)
+{
+  bool num_256_available_p = true;
+  int i;
+
+  /* Find the highest user token number, and whether 256, the POSIX
+     preferred user token number for the error token, is used.  */
+  max_user_token_number = 0;
+  for (i = 0; i < ntokens; ++i)
+    {
+      symbol *this = symbols[i];
+      if (this->user_token_number != USER_NUMBER_UNDEFINED)

        {
        {

-         bptmp = bp->link;
-#if 0 /* This causes crashes because one string can appear more than once.  */
-         if (bp->type_name)
-           XFREE(bp->type_name);
-#endif
-         XFREE(bp);
-         bp = bptmp;
+         if (this->user_token_number > max_user_token_number)
+           max_user_token_number = this->user_token_number;
+         if (this->user_token_number == 256)
+           num_256_available_p = false;

        }
     }
        }
     }

-  XFREE(symtab);
+
+  /* If 256 is not used, assign it to error, to follow POSIX.  */
+  if (num_256_available_p
+      && errtoken->user_token_number == USER_NUMBER_UNDEFINED)
+    errtoken->user_token_number = 256;
+
+  /* Set the missing user numbers. */
+  if (max_user_token_number < 256)
+    max_user_token_number = 256;
+
+  for (i = 0; i < ntokens; ++i)
+    {
+      symbol *this = symbols[i];
+      if (this->user_token_number == USER_NUMBER_UNDEFINED)
+       this->user_token_number = ++max_user_token_number;
+      if (this->user_token_number > max_user_token_number)
+       max_user_token_number = this->user_token_number;
+    }
+
+  token_translations = xnmalloc (max_user_token_number + 1,
+                                sizeof *token_translations);
+
+  /* Initialize all entries for literal tokens to 2, the internal
+     token number for $undefined, which represents all invalid inputs.
+     */
+  for (i = 0; i < max_user_token_number + 1; i++)
+    token_translations[i] = undeftoken->number;
+  symbols_do (symbol_translation_processor, NULL);
+}
+
+
+/*----------------------------------------------------------------.
+| Assign symbol numbers, and write definition of token names into |
+| FDEFINES.  Set up vectors SYMBOL_TABLE, TAGS of symbols.        |
+`----------------------------------------------------------------*/
+
+void
+symbols_pack (void)
+{
+  symbols = xcalloc (nsyms, sizeof *symbols);
+
+  symbols_do (symbol_check_alias_consistency_processor, NULL);
+  symbols_do (symbol_pack_processor, NULL);
+
+  symbols_token_translations_init ();
+
+  if (startsymbol->class == unknown_sym)
+    fatal_at (startsymbol_location,
+             _("the start symbol %s is undefined"),
+             startsymbol->tag);
+  else if (startsymbol->class == token_sym)
+    fatal_at (startsymbol_location,
+             _("the start symbol %s is a token"),
+             startsymbol->tag);

 }
 }