X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/4a120d45e6a181ced2f24f2f6d23e2faa9fbd778..d1a1114f7f257f89887ea5825ba0d896dfaa747b:/src/symtab.c

diff --git a/src/symtab.c b/src/symtab.c
index 55beb391..7b313120 100644
--- a/src/symtab.c
+++ b/src/symtab.c
@@ -1,150 +1,574 @@
 /* Symbol table manager for Bison,
-   Copyright (C) 1984, 1989 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
 
-This file is part of Bison, the GNU Compiler Compiler.
+   This file is part of Bison, the GNU Compiler Compiler.
 
-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.
+   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.
 
-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 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.  */
+   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 <stdio.h>
 #include "system.h"
-#include "alloc.h"
+#include "quotearg.h"
+#include "hash.h"
+#include "complain.h"
 #include "symtab.h"
 #include "gram.h"
 
+/*------------------------.
+| Distinguished symbols.  |
+`------------------------*/
 
-bucket *firstsymbol;
-static bucket *lastsymbol;
-static bucket **symtab;
+symbol_t *errtoken = NULL;
+symbol_t *undeftoken = NULL;
+symbol_t *endtoken = NULL;
+symbol_t *accept = NULL;
+symbol_t *startsymbol = NULL;
+location_t startsymbol_location;
 
-extern void tabinit PARAMS((void));
-extern void free_symtab PARAMS((void));
+/*---------------------------------.
+| Create a new symbol, named TAG.  |
+`---------------------------------*/
 
+static symbol_t *
+symbol_new (const char *tag, location_t location)
+{
+  symbol_t *res = XMALLOC (symbol_t, 1);
+
+  res->tag = xstrdup (tag);
+  res->location = location;
+
+  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;
+
+  nsyms++;
+  return res;
+}
+
+
+/*------------------------------------------------------------------.
+| Set the TYPE_NAME associated to SYMBOL.  Does nothing if passed 0 |
+| as TYPE_NAME.                                                     |
+`------------------------------------------------------------------*/
+
+void
+symbol_type_set (symbol_t *symbol, char *type_name, location_t location)
+{
+  if (type_name)
+    {
+      if (symbol->type_name)
+	complain_at (location,
+		     _("type redeclaration for %s"), symbol->tag);
+      symbol->type_name = type_name;
+    }
+}
+
+
+/*-------------------------------------------------------------------.
+| Set the DESTRUCTOR associated to SYMBOL.  Do nothing if passed 0.  |
+`-------------------------------------------------------------------*/
+
+void
+symbol_destructor_set (symbol_t *symbol, char *destructor, location_t location)
+{
+  if (destructor)
+    {
+      if (symbol->destructor)
+	complain_at (location,
+		     _("%s redeclaration for %s"),
+		     "%destructor", symbol->tag);
+      symbol->destructor = destructor;
+      symbol->destructor_location = location;
+    }
+}
 
-static int
-hash (const char *key)
+
+/*----------------------------------------------------------------.
+| Set the PRITNER associated to SYMBOL.  Do nothing if passed 0.  |
+`----------------------------------------------------------------*/
+
+void
+symbol_printer_set (symbol_t *symbol, char *printer, location_t location)
 {
-  register const char *cp;
-  register int k;
+  if (printer)
+    {
+      if (symbol->printer)
+	complain_at (location,
+		     _("%s redeclaration for %s"),
+		     "%printer", symbol->tag);
+      symbol->printer = printer;
+      symbol->printer_location = location;
+    }
+}
+
 
-  cp = key;
-  k = 0;
-  while (*cp)
-    k = ((k << 1) ^ (*cp++)) & 0x3fff;
+/*------------------------------------------------------------------.
+| Set the PRECEDENCE associated to SYMBOL.  Does nothing if invoked |
+| with UNDEF_ASSOC as ASSOC.                                        |
+`------------------------------------------------------------------*/
 
-  return k % TABSIZE;
+void
+symbol_precedence_set (symbol_t *symbol,
+		       int prec, assoc_t assoc, location_t location)
+{
+  if (assoc != undef_assoc)
+    {
+      if (symbol->prec != 0)
+	complain_at (location,
+		     _("redefining precedence of %s"),
+		     symbol->tag);
+      symbol->prec = prec;
+      symbol->assoc = assoc;
+    }
+
+  /* Only terminals have a precedence. */
+  symbol_class_set (symbol, token_sym, location);
 }
 
 
+/*-------------------------------------.
+| Set the CLASS associated to SYMBOL.  |
+`-------------------------------------*/
 
-static char *
-copys (const char *s)
+void
+symbol_class_set (symbol_t *symbol, symbol_class class, location_t location)
 {
-  register int i;
-  register const char *cp;
-  register char *result;
+  if (symbol->class != unknown_sym && symbol->class != class)
+    complain_at (location, _("symbol %s redefined"), symbol->tag);
 
-  i = 1;
-  for (cp = s; *cp; cp++)
-    i++;
+  if (class == nterm_sym && symbol->class != nterm_sym)
+    symbol->number = nvars++;
+  else if (class == token_sym && symbol->number == NUMBER_UNDEFINED)
+    symbol->number = ntokens++;
 
-  result = xmalloc((unsigned int)i);
-  strcpy(result, s);
-  return result;
+  symbol->class = class;
 }
 
 
+/*-------------------------------------------------.
+| Set the USER_TOKEN_NUMBER associated to SYMBOL.  |
+`-------------------------------------------------*/
+
 void
-tabinit (void)
+symbol_user_token_number_set (symbol_t *symbol,
+			      int user_token_number, location_t location)
 {
-/*   register int i; JF unused */
+  assert (symbol->class == token_sym);
 
-  symtab = NEW2(TABSIZE, bucket *);
+  if (symbol->user_token_number != USER_NUMBER_UNDEFINED
+      && symbol->user_token_number != user_token_number)
+    complain_at (location, _("redefining user token number of %s"),
+		 symbol->tag);
 
-  firstsymbol = NULL;
-  lastsymbol = NULL;
+  symbol->user_token_number = user_token_number;
+  /* User defined $end token? */
+  if (user_token_number == 0)
+    {
+      endtoken = symbol;
+      endtoken->number = 0;
+      /* It is always mapped to 0, so it was already counted in
+	 NTOKENS.  */
+      --ntokens;
+    }
 }
 
 
-bucket *
-getsym (const char *key)
+/*------------.
+| Free THIS.  |
+`------------*/
+
+static void
+symbol_free (symbol_t *this)
 {
-  register int hashval;
-  register bucket *bp;
-  register int found;
+#if 0
+  /* This causes crashes because one string can appear more
+     than once.  */
+  XFREE (this->type_name);
+#endif
+  XFREE (this->tag);
+  XFREE (this);
+}
+
 
-  hashval = hash(key);
-  bp = symtab[hashval];
+/*-----------------------------------------------------------.
+| If THIS is not defined, report an error, and consider it a |
+| nonterminal.                                               |
+`-----------------------------------------------------------*/
 
-  found = 0;
-  while (bp != NULL && found == 0)
+static bool
+symbol_check_defined (symbol_t *this)
+{
+  if (this->class == unknown_sym)
     {
-      if (strcmp(key, bp->tag) == 0)
-	found = 1;
-      else
-	bp = bp->link;
+      complain_at
+	(this->location,
+	 _("symbol %s is used, but is not defined as a token and has no rules"),
+	 this->tag);
+      this->class = nterm_sym;
+      this->number = nvars++;
     }
 
-  if (found == 0)
+  return TRUE;
+}
+
+
+/*-------------------------------------------------------------------.
+| Declare the new SYMBOL.  Make it an alias of SYMVAL, and type them |
+| with TYPENAME.                                                     |
+`-------------------------------------------------------------------*/
+
+void
+symbol_make_alias (symbol_t *symbol, symbol_t *symval, location_t loc)
+{
+  if (symval->alias)
+    warn_at (loc, _("symbol `%s' used more than once as a literal string"),
+	  symval->tag);
+  else if (symbol->alias)
+    warn_at (loc, _("symbol `%s' given more than one literal string"),
+	  symbol->tag);
+  else
     {
-      nsyms++;
+      symval->class = token_sym;
+      symval->user_token_number = symbol->user_token_number;
+      symbol->user_token_number = USER_NUMBER_ALIAS;
+      symval->alias = symbol;
+      symbol->alias = symval;
+      /* symbol and symval combined are only one symbol */
+      nsyms--;
+      ntokens--;
+      assert (ntokens == symbol->number || ntokens == symval->number);
+      symbol->number = symval->number =
+	(symval->number < symbol->number) ? symval->number : symbol->number;
+    }
+}
+
+
+/*---------------------------------------------------------.
+| Check that THIS, and its alias, have same precedence and |
+| associativity.                                           |
+`---------------------------------------------------------*/
 
-      bp = NEW(bucket);
-      bp->link = symtab[hashval];
-      bp->next = NULL;
-      bp->tag = copys(key);
-      bp->class = SUNKNOWN;
+static bool
+symbol_check_alias_consistence (symbol_t *this)
+{
+  /* Check only those who _are_ the aliases. */
+  if (this->alias && this->user_token_number == USER_NUMBER_ALIAS)
+    {
+      if (this->prec != this->alias->prec)
+	{
+	  if (this->prec != 0 && this->alias->prec != 0)
+	    complain_at (this->alias->location,
+			 _("conflicting precedences for %s and %s"),
+			 this->tag, this->alias->tag);
+	  if (this->prec != 0)
+	    this->alias->prec = this->prec;
+	  else
+	    this->prec = this->alias->prec;
+	}
 
-      if (firstsymbol == NULL)
+      if (this->assoc != this->alias->assoc)
 	{
-	  firstsymbol = bp;
-	  lastsymbol = bp;
+	  if (this->assoc != undef_assoc && this->alias->assoc != undef_assoc)
+	    complain_at (this->alias->location,
+			 _("conflicting associativities for %s (%s) and %s (%s)"),
+			 this->tag, assoc_to_string (this->assoc),
+			 this->alias->tag, assoc_to_string (this->alias->assoc));
+	  if (this->assoc != undef_assoc)
+	    this->alias->assoc = this->assoc;
+	  else
+	    this->assoc = this->alias->assoc;
 	}
-      else
+    }
+  return TRUE;
+}
+
+
+/*-------------------------------------------------------------------.
+| Assign a symbol number, and write the definition of the token name |
+| into FDEFINES.  Put in SYMBOLS.                                    |
+`-------------------------------------------------------------------*/
+
+static bool
+symbol_pack (symbol_t *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
+	    {
+	      assert (this->alias->number != NUMBER_UNDEFINED);
+	      this->number = this->alias->number;
+	    }
 	}
+      /* Do not do processing below for USER_NUMBER_ALIASs.  */
+      if (this->user_token_number == USER_NUMBER_ALIAS)
+	return TRUE;
+    }
+  else /* this->class == token_sym */
+    {
+      assert (this->number != NUMBER_UNDEFINED);
+    }
+
+  symbols[this->number] = this;
+  return TRUE;
+}
 
-      symtab[hashval] = bp;
+
+
+
+/*--------------------------------------------------.
+| Put THIS in TOKEN_TRANSLATIONS if it is a token.  |
+`--------------------------------------------------*/
+
+static bool
+symbol_translation (symbol_t *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 TRUE;
+}
+
+
+/*----------------------.
+| A symbol hash table.  |
+`----------------------*/
+
+/* Initial capacity of symbols hash table.  */
+#define HT_INITIAL_CAPACITY 257
+
+static struct hash_table *symbol_table = NULL;
+
+static bool
+hash_compare_symbol_t (const symbol_t *m1, const symbol_t *m2)
+{
+  return strcmp (m1->tag, m2->tag) ? FALSE : TRUE;
+}
+
+static unsigned int
+hash_symbol_t (const symbol_t *m, unsigned int tablesize)
+{
+  return hash_string (m->tag, tablesize);
+}
+
+
+/*-------------------------------.
+| Create the symbol hash table.  |
+`-------------------------------*/
+
+void
+symbols_new (void)
+{
+  symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
+				  NULL,
+				  (Hash_hasher) hash_symbol_t,
+				  (Hash_comparator) hash_compare_symbol_t,
+				  (Hash_data_freer) symbol_free);
+}
+
+
+/*----------------------------------------------------------------.
+| Find the symbol named KEY, and return it.  If it does not exist |
+| yet, create it.                                                 |
+`----------------------------------------------------------------*/
+
+symbol_t *
+symbol_get (const char *key, location_t location)
+{
+  symbol_t probe;
+  symbol_t *entry;
+
+  /* Keep the symbol in a printable form.  */
+  key = quotearg_style (escape_quoting_style, key);
+  *(char const **) &probe.tag = key;
+  entry = hash_lookup (symbol_table, &probe);
+
+  if (!entry)
+    {
+      /* First insertion in the hash. */
+      entry = symbol_new (key, location);
+      hash_insert (symbol_table, entry);
     }
+  return entry;
+}
+
+
+/*------------------------------------------------------------------.
+| Generate a dummy nonterminal, whose name cannot conflict with the |
+| user's names.                                                     |
+`------------------------------------------------------------------*/
+
+symbol_t *
+dummy_symbol_get (location_t location)
+{
+  /* Incremented for each generated symbol.  */
+  static int dummy_count = 0;
+  static char buf[256];
+
+  symbol_t *sym;
+
+  sprintf (buf, "@%d", ++dummy_count);
+  sym = symbol_get (buf, location);
+  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.                                                     |
+`---------------------------------------------------------------*/
 
-  return bp;
+void
+symbols_do (symbol_processor processor, void *processor_data)
+{
+  hash_do_for_each (symbol_table,
+		    (Hash_processor) processor,
+		    processor_data);
 }
 
 
+/*--------------------------------------------------------------.
+| Check that all the symbols are defined.  Report any undefined |
+| symbols and consider them nonterminals.                       |
+`--------------------------------------------------------------*/
+
 void
-free_symtab (void)
+symbols_check_defined (void)
+{
+  symbols_do (symbol_check_defined, NULL);
+}
+
+/*------------------------------------------------------------------.
+| Set TOKEN_TRANSLATIONS.  Check that no two symbols share the same |
+| number.                                                           |
+`------------------------------------------------------------------*/
+
+static void
+symbols_token_translations_init (void)
 {
-  register int i;
-  register bucket *bp,*bptmp;/* JF don't use ptr after free */
+  int num_256_available_p = TRUE;
+  int i;
 
-  for (i = 0; i < TABSIZE; 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)
     {
-      bp = symtab[i];
-      while (bp)
+      symbol_t *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)
-	    FREE(bp->type_name);
-#endif
-	  FREE(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;
 	}
     }
-  FREE(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_t *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 = XCALLOC (symbol_number_t, max_user_token_number + 1);
+
+  /* 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, 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 (symbol_t *, nsyms);
+
+  symbols_do (symbol_check_alias_consistence, NULL);
+  symbols_do (symbol_pack, 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);
 }