X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/3067fbef531832df1e43bbd28787655808361eed..e9f87b5b7df2e328d2e4196d276c0d96594c906b:/src/reader.c

diff --git a/src/reader.c b/src/reader.c
index 6bfc7d73..cf3e18f3 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -21,7 +21,6 @@
 
 
 #include "system.h"
-#include "obstack.h"
 #include "quotearg.h"
 #include "quote.h"
 #include "getargs.h"
@@ -41,13 +40,18 @@ typedef struct symbol_list
   struct symbol_list *next;
   bucket *sym;
   int line;
+
+  /* The action is attached to the LHS of a rule. */
+  const char *action;
+  int action_line;
+
+  /* The guard is attached to the LHS of a rule. */
+  const char *guard;
+  int guard_line;
   bucket *ruleprec;
-}
-symbol_list;
+} symbol_list;
 
 int lineno;
-char **tags;
-short *user_toknums;
 static symbol_list *grammar;
 static int start_flag;
 static bucket *startval;
@@ -62,9 +66,10 @@ static int typed;
 /* Incremented for each %left, %right or %nonassoc seen */
 static int lastprec;
 
-static bucket *errtoken;
-static bucket *undeftoken;
-
+static bucket *errtoken = NULL;
+static bucket *undeftoken = NULL;
+static bucket *eoftoken = NULL;
+static bucket *axiom = NULL;
 
 static symbol_list *
 symbol_list_new (bucket *sym)
@@ -73,6 +78,10 @@ symbol_list_new (bucket *sym)
   res->next = NULL;
   res->sym = sym;
   res->line = lineno;
+  res->action = NULL;
+  res->action_line = 0;
+  res->guard = NULL;
+  res->guard_line = 0;
   res->ruleprec = NULL;
   return res;
 }
@@ -230,25 +239,22 @@ copy_identifier (FILE *fin, struct obstack *oout)
   ungetc (c, fin);
 }
 
-/*-----------------------------------------------------------------.
-| Dump the wannabee comment from IN to OUT1 and OUT2 (which can be |
-| NULL).  In fact we just saw a `/', which might or might not be a |
-| comment.  In any case, copy what we saw.                         |
-|                                                                  |
-| OUT2 might be NULL.                                              |
-`-----------------------------------------------------------------*/
+
+/*------------------------------------------------------------------.
+| Dump the wannabee comment from IN to OOUT.  In fact we just saw a |
+| `/', which might or might not be a comment.  In any case, copy    |
+| what we saw.                                                      |
+`------------------------------------------------------------------*/
 
 static inline void
-copy_comment2 (FILE *fin, struct obstack *oout1, struct obstack *oout2)
+copy_comment (FILE *fin, struct obstack *oout)
 {
   int cplus_comment;
   int ended;
   int c;
 
   /* We read a `/', output it. */
-  obstack_1grow (oout1, '/');
-  if (oout2)
-    obstack_1grow (oout2, '/');
+  obstack_1grow (oout, '/');
 
   switch ((c = getc (fin)))
     {
@@ -263,9 +269,7 @@ copy_comment2 (FILE *fin, struct obstack *oout1, struct obstack *oout2)
       return;
     }
 
-  obstack_1grow (oout1, c);
-  if (oout2)
-    obstack_1grow (oout2, c);
+  obstack_1grow (oout, c);
   c = getc (fin);
 
   ended = 0;
@@ -275,26 +279,20 @@ copy_comment2 (FILE *fin, struct obstack *oout1, struct obstack *oout2)
 	{
 	  while (c == '*')
 	    {
-	      obstack_1grow (oout1, c);
-	      if (oout2)
-		obstack_1grow (oout2, c);
+	      obstack_1grow (oout, c);
 	      c = getc (fin);
 	    }
 
 	  if (c == '/')
 	    {
-	      obstack_1grow (oout1, c);
-	      if (oout2)
-		obstack_1grow (oout2, c);
+	      obstack_1grow (oout, c);
 	      ended = 1;
 	    }
 	}
       else if (c == '\n')
 	{
 	  lineno++;
-	  obstack_1grow (oout1, c);
-	  if (oout2)
-	    obstack_1grow (oout2, c);
+	  obstack_1grow (oout, c);
 	  if (cplus_comment)
 	    ended = 1;
 	  else
@@ -304,27 +302,13 @@ copy_comment2 (FILE *fin, struct obstack *oout1, struct obstack *oout2)
 	fatal (_("unterminated comment"));
       else
 	{
-	  obstack_1grow (oout1, c);
-	  if (oout2)
-	    obstack_1grow (oout2, c);
+	  obstack_1grow (oout, c);
 	  c = getc (fin);
 	}
     }
 }
 
 
-/*-------------------------------------------------------------------.
-| Dump the comment (actually the current string starting with a `/') |
-| from FIN to OOUT.                                                  |
-`-------------------------------------------------------------------*/
-
-static inline void
-copy_comment (FILE *fin, struct obstack *oout)
-{
-  copy_comment2 (fin, oout, NULL);
-}
-
-
 /*-----------------------------------------------------------------.
 | FIN is pointing to a location (i.e., a `@').  Output to OOUT a   |
 | reference to this location. STACK_OFFSET is the number of values |
@@ -349,9 +333,16 @@ copy_at (FILE *fin, struct obstack *oout, int stack_offset)
 
       ungetc (c, fin);
       n = read_signed_integer (fin);
-
-      obstack_fgrow1 (oout, "yylsp[%d]", n - stack_offset);
-      locations_flag = 1;
+      if (n > stack_offset)
+	complain (_("invalid value: %s%d"), "@", n);
+      else
+	{
+	  /* Offset is always 0 if parser has already popped the stack
+	     pointer.  */
+	  obstack_fgrow1 (oout, "yylsp[%d]",
+			  n - (semantic_parser ? 0 : stack_offset));
+	  locations_flag = 1;
+	}
     }
   else
     {
@@ -406,16 +397,24 @@ copy_dollar (FILE *fin, struct obstack *oout,
       ungetc (c, fin);
       n = read_signed_integer (fin);
 
-      if (!type_name && n > 0)
-	type_name = get_type_name (n, rule);
-
-      obstack_fgrow1 (oout, "yyvsp[%d]", n - stack_offset);
-
-      if (type_name)
-	obstack_fgrow1 (oout, ".%s", type_name);
-      if (!type_name && typed)
-	complain (_("$%d of `%s' has no declared type"),
-		  n, rule->sym->tag);
+      if (n > stack_offset)
+	complain (_("invalid value: %s%d"), "$", n);
+      else
+	{
+	  if (!type_name && n > 0)
+	    type_name = get_type_name (n, rule);
+
+	  /* Offset is always 0 if parser has already popped the stack
+	     pointer.  */
+	  obstack_fgrow1 (oout, "yyvsp[%d]",
+			  n - (semantic_parser ? 0 : stack_offset));
+
+	  if (type_name)
+	    obstack_fgrow1 (oout, ".%s", type_name);
+	  if (!type_name && typed)
+	    complain (_("$%d of `%s' has no declared type"),
+		      n, rule->sym->tag);
+	}
     }
   else
     {
@@ -437,14 +436,12 @@ copy_definition (void)
   /* -1 while reading a character if prev char was %. */
   int after_percent;
 
-#if 0
   if (!no_lines_flag)
     {
       obstack_fgrow2 (&attrs_obstack, muscle_find ("linef"),
 		      lineno, quotearg_style (c_quoting_style,
-					      muscle_find("filename")));
+					      muscle_find ("filename")));
     }
-#endif
 
   after_percent = 0;
 
@@ -575,6 +572,9 @@ parse_token_decl (symbol_class what_is, symbol_class what_is_not)
       else if (symbol && token == tok_number)
 	{
 	  symbol->user_token_number = numval;
+	  /* User defined EOF token? */
+	  if (numval == 0)
+	    eoftoken = symbol;
 	}
       else
 	{
@@ -752,43 +752,23 @@ parse_union_decl (void)
 {
   int c;
   int count = 0;
+  bool done = FALSE;
   struct obstack union_obstack;
-  const char *prologue = "\
-#ifndef YYSTYPE\n\
-typedef union";
-  const char *epilogue = "\
- yystype;\n\
-# define YYSTYPE yystype\n\
-#endif\n";
-
   if (typed)
     complain (_("multiple %s declarations"), "%union");
 
   typed = 1;
 
-  /* FIXME: I'm worried: are you sure attrs_obstack is properly
-     filled?  */
-  /* I don't see any reasons to keep this line, because we should
-     create a special skeleton for this option.  */
-  if (no_lines_flag)
-    obstack_1grow (&attrs_obstack, '\n');
-
   obstack_init (&union_obstack);
   obstack_sgrow (&union_obstack, "union");
-  if (defines_flag)
-    obstack_sgrow (&defines_obstack, prologue);
-
-  c = getc (finput);
 
-  while (c != EOF)
+  while (!done)
     {
+      c = xgetc (finput);
+
       /* If C contains '/', it is output by copy_comment ().  */
       if (c != '/')
-	{
-	  obstack_1grow (&union_obstack, c);
-	  if (defines_flag)
-	    obstack_1grow (&defines_obstack, c);
-	}
+	obstack_1grow (&union_obstack, c);
 
       switch (c)
 	{
@@ -797,7 +777,7 @@ typedef union";
 	  break;
 
 	case '/':
-	  copy_comment2 (finput, &defines_obstack, &union_obstack);
+	  copy_comment (finput, &union_obstack);
 	  break;
 
 	case '{':
@@ -805,26 +785,22 @@ typedef union";
 	  break;
 
 	case '}':
+	  /* FIXME: Errr.  How could this happen???. --akim */
 	  if (count == 0)
 	    complain (_("unmatched %s"), "`}'");
 	  count--;
-	  if (count <= 0)
-	    {
-	      if (defines_flag)
-		obstack_sgrow (&defines_obstack, epilogue);
-	      /* JF don't choke on trailing semi */
-	      c = skip_white_space ();
-	      if (c != ';')
-		ungetc (c, finput);
-	      obstack_1grow (&union_obstack, 0);
-	      muscle_insert ("stype", obstack_finish (&union_obstack));
-	      return;
-	    }
+	  if (!count)
+	    done = TRUE;
+	  break;
 	}
-
-      c = getc (finput);
     }
 
+  /* JF don't choke on trailing semi */
+  c = skip_white_space ();
+  if (c != ';')
+    ungetc (c, finput);
+  obstack_1grow (&union_obstack, 0);
+  muscle_insert ("stype", obstack_finish (&union_obstack));
 }
 
 
@@ -923,12 +899,13 @@ parse_thong_decl (void)
   nsyms--;
 }
 
+
 static void
 parse_muscle_decl (void)
 {
   int ch = ungetc (skip_white_space (), finput);
-  char* muscle_key;
-  char* muscle_value;
+  char *muscle_key;
+  char *muscle_value;
 
   /* Read key. */
   if (!isalpha (ch) && ch != '_')
@@ -966,7 +943,7 @@ parse_muscle_decl (void)
 
 
 /*---------------------------------.
-| Parse a double quoted parameter. |       
+| Parse a double quoted parameter. |
 `---------------------------------*/
 
 static const char *
@@ -987,14 +964,9 @@ parse_dquoted_param (const char *from)
       return NULL;
     }
 
-  for (;;)
-    {
-      if (literalchar (NULL, &c, '\"'))
-	obstack_1grow (&param_obstack, c);
-      else
-	break;
-    }
-  
+  while ((c = literalchar ()) != '"')
+    obstack_1grow (&param_obstack, c);
+
   obstack_1grow (&param_obstack, '\0');
   param = obstack_finish (&param_obstack);
 
@@ -1014,7 +986,7 @@ parse_dquoted_param (const char *from)
 | Parse what comes after %skeleton. |
 `----------------------------------*/
 
-void
+static void
 parse_skel_decl (void)
 {
   skeleton = parse_dquoted_param ("%skeleton");
@@ -1126,187 +1098,89 @@ read_declarations (void)
 | matching `}' into the actions file.  STACK_OFFSET is the number of |
 | values in the current rule so far, which says where to find `$0'   |
 | with respect to the top of the stack.                              |
+|                                                                    |
+| This routine is used both for actions and guards.  Only            |
+| ACTION_OBSTACK is used, but this is fine, since we use only        |
+| pointers to relevant portions inside this obstack.                 |
 `-------------------------------------------------------------------*/
 
 static void
-copy_action (symbol_list *rule, int stack_offset)
+parse_braces (symbol_list *rule, int stack_offset)
 {
   int c;
   int count;
-  char buf[4096];
-
-  /* offset is always 0 if parser has already popped the stack pointer */
-  if (semantic_parser)
-    stack_offset = 0;
-
-  obstack_fgrow1 (&action_obstack, "\ncase %d:\n", nrules);
-
-  if (!no_lines_flag)
-    {
-      obstack_fgrow2 (&action_obstack, muscle_find ("linef"),
-		      lineno, quotearg_style (c_quoting_style,
-					      muscle_find ("filename")));
-    }
-  obstack_1grow (&action_obstack, '{');
 
   count = 1;
-  c = getc (finput);
-
   while (count > 0)
     {
-      while (c != '}')
-	{
-	  switch (c)
-	    {
-	    case '\n':
-	      obstack_1grow (&action_obstack, c);
-	      lineno++;
-	      break;
-
-	    case '{':
-	      obstack_1grow (&action_obstack, c);
-	      count++;
-	      break;
-
-	    case '\'':
-	    case '"':
-	      copy_string (finput, &action_obstack, c);
-	      break;
+      while ((c = getc (finput)) != '}')
+	switch (c)
+	  {
+	  case '\n':
+	    obstack_1grow (&action_obstack, c);
+	    lineno++;
+	    break;
 
-	    case '/':
-	      copy_comment (finput, &action_obstack);
-	      break;
+	  case '{':
+	    obstack_1grow (&action_obstack, c);
+	    count++;
+	    break;
 
-	    case '$':
-	      copy_dollar (finput, &action_obstack,
-			   rule, stack_offset);
-	      break;
+	  case '\'':
+	  case '"':
+	    copy_string (finput, &action_obstack, c);
+	    break;
 
-	    case '@':
-	      copy_at (finput, &action_obstack,
-		       stack_offset);
-	      break;
+	  case '/':
+	    copy_comment (finput, &action_obstack);
+	    break;
 
-	    case EOF:
-	      fatal (_("unmatched %s"), "`{'");
+	  case '$':
+	    copy_dollar (finput, &action_obstack,
+			 rule, stack_offset);
+	    break;
 
-	    default:
-	      obstack_1grow (&action_obstack, c);
-	    }
+	  case '@':
+	    copy_at (finput, &action_obstack,
+		     stack_offset);
+	    break;
 
-	  c = getc (finput);
-	}
+	  case EOF:
+	    fatal (_("unmatched %s"), "`{'");
 
-      /* above loop exits when c is '}' */
+	  default:
+	    obstack_1grow (&action_obstack, c);
+	  }
 
+      /* Above loop exits when C is '}'.  */
       if (--count)
-	{
-	  obstack_1grow (&action_obstack, c);
-	  c = getc (finput);
-	}
+	obstack_1grow (&action_obstack, c);
     }
 
-  obstack_sgrow (&action_obstack, ";\n    break;}");
+  obstack_1grow (&action_obstack, '\0');
 }
-
-/*-------------------------------------------------------------------.
-| After `%guard' is seen in the input file, copy the actual guard    |
-| into the guards file.  If the guard is followed by an action, copy |
-| that into the actions file.  STACK_OFFSET is the number of values  |
-| in the current rule so far, which says where to find `$0' with     |
-| respect to the top of the stack, for the simple parser in which    |
-| the stack is not popped until after the guard is run.              |
-`-------------------------------------------------------------------*/
+
 
 static void
-copy_guard (symbol_list *rule, int stack_offset)
+parse_action (symbol_list *rule, int stack_offset)
 {
-  int c;
-  int count;
-  int brace_flag = 0;
-
-  /* offset is always 0 if parser has already popped the stack pointer */
-  if (semantic_parser)
-    stack_offset = 0;
-
-  obstack_fgrow1 (&guard_obstack, "\ncase %d:\n", nrules);
-  if (!no_lines_flag)
-    obstack_fgrow2 (&guard_obstack, muscle_find ("linef"),
-		    lineno, quotearg_style (c_quoting_style,
-					    muscle_find ("filename")));
-  obstack_1grow (&guard_obstack, '{');
-
-  count = 0;
-  c = getc (finput);
-
-  while (brace_flag ? (count > 0) : (c != ';'))
-    {
-      switch (c)
-	{
-	case '\n':
-	  obstack_1grow (&guard_obstack, c);
-	  lineno++;
-	  break;
-
-	case '{':
-	  obstack_1grow (&guard_obstack, c);
-	  brace_flag = 1;
-	  count++;
-	  break;
-
-	case '}':
-	  obstack_1grow (&guard_obstack, c);
-	  if (count > 0)
-	    count--;
-	  else
-	    {
-	      complain (_("unmatched %s"), "`}'");
-	      c = getc (finput);	/* skip it */
-	    }
-	  break;
-
-	case '\'':
-	case '"':
-	  copy_string (finput, &guard_obstack, c);
-	  break;
-
-	case '/':
-	  copy_comment (finput, &guard_obstack);
-	  break;
-
-	case '$':
-	  copy_dollar (finput, &guard_obstack, rule, stack_offset);
-	  break;
-
-	case '@':
-	  copy_at (finput, &guard_obstack, stack_offset);
-	  break;
-
-	case EOF:
-	  fatal ("%s", _("unterminated %guard clause"));
-
-	default:
-	  obstack_1grow (&guard_obstack, c);
-	}
-
-      if (c != '}' || count != 0)
-	c = getc (finput);
-    }
+  rule->action_line = lineno;
+  parse_braces (rule, stack_offset);
+  rule->action = obstack_finish (&action_obstack);
+}
 
-  c = skip_white_space ();
 
-  obstack_sgrow (&guard_obstack, ";\n    break;}");
-  if (c == '{')
-    copy_action (rule, stack_offset);
-  else if (c == '=')
-    {
-      c = getc (finput);	/* why not skip_white_space -wjh */
-      if (c == '{')
-	copy_action (rule, stack_offset);
-    }
-  else
-    ungetc (c, finput);
+static void
+parse_guard (symbol_list *rule, int stack_offset)
+{
+  token_t t = lex ();
+  if (t != tok_left_curly)
+    complain (_("invalid %s declaration"), "%guard");
+  rule->guard_line = lineno;
+  parse_braces (rule, stack_offset);
+  rule->guard = obstack_finish (&action_obstack);
 }
+
 
 
 /*-------------------------------------------------------------------.
@@ -1330,338 +1204,255 @@ gensym (void)
   sym->value = nvars++;
   return sym;
 }
-
-#if 0
-/*------------------------------------------------------------------.
-| read in a %type declaration and record its information for        |
-| get_type_name to access.  This is unused.  It is only called from |
-| the #if 0 part of readgram                                        |
-`------------------------------------------------------------------*/
-
-static int
-get_type (void)
-{
-  int k;
-  token_t token;
-  char *name;
-
-  token = lex ();
-
-  if (token != tok_typename)
-    {
-      complain (_("invalid %s declaration"), "%type");
-      return t;
-    }
-
-  name = xstrdup (token_buffer);
-
-  for (;;)
-    {
-      token = lex ();
-
-      switch (token)
-	{
-	case tok_semicolon:
-	  return lex ();
-
-	case tok_comma:
-	  break;
-
-	case tok_identifier:
-	  if (symval->type_name == NULL)
-	    symval->type_name = name;
-	  else if (strcmp (name, symval->type_name) != 0)
-	    complain (_("type redeclaration for %s"), symval->tag);
-
-	  break;
-
-	default:
-	  return token;
-	}
-    }
-}
-
-#endif
 
-/*------------------------------------------------------------------.
-| Parse the input grammar into a one symbol_list structure.  Each   |
-| rule is represented by a sequence of symbols: the left hand side  |
-| followed by the contents of the right hand side, followed by a    |
-| null pointer instead of a symbol to terminate the rule.  The next |
-| symbol is the lhs of the following rule.                          |
-|                                                                   |
-| All guards and actions are copied out to the appropriate files,   |
-| labelled by the rule number they apply to.                        |
-`------------------------------------------------------------------*/
+/*-------------------------------------------------------------------.
+| Parse the input grammar into a one symbol_list structure.  Each    |
+| rule is represented by a sequence of symbols: the left hand side   |
+| followed by the contents of the right hand side, followed by a     |
+| null pointer instead of a symbol to terminate the rule.  The next  |
+| symbol is the lhs of the following rule.                           |
+|                                                                    |
+| All guards and actions are copied out to the appropriate files,    |
+| labelled by the rule number they apply to.                         |
+|                                                                    |
+| Bison used to allow some %directives in the rules sections, but    |
+| this is no longer consider appropriate: (i) the documented grammar |
+| doesn't claim it, (ii), it would promote bad style, (iii), error   |
+| recovery for %directives consists in skipping the junk until a `%' |
+| is seen and helrp synchronizing.  This scheme is definitely wrong  |
+| in the rules section.                                              |
+`-------------------------------------------------------------------*/
 
 static void
 readgram (void)
 {
   token_t t;
   bucket *lhs = NULL;
-  symbol_list *p;
-  symbol_list *p1;
+  symbol_list *p = NULL;
+  symbol_list *p1 = NULL;
   bucket *bp;
 
   /* Points to first symbol_list of current rule. its symbol is the
      lhs of the rule.  */
-  symbol_list *crule;
+  symbol_list *crule = NULL;
   /* Points to the symbol_list preceding crule.  */
-  symbol_list *crule1;
-
-  p1 = NULL;
+  symbol_list *crule1 = NULL;
 
   t = lex ();
 
   while (t != tok_two_percents && t != tok_eof)
-    {
-      if (t == tok_identifier || t == tok_bar)
-	{
-	  int action_flag = 0;
-	  /* Number of symbols in rhs of this rule so far */
-	  int rulelength = 0;
-	  int xactions = 0;	/* JF for error checking */
-	  bucket *first_rhs = 0;
-
-	  if (t == tok_identifier)
-	    {
-	      lhs = symval;
-
-	      if (!start_flag)
-		{
-		  startval = lhs;
-		  start_flag = 1;
-		}
-
-	      t = lex ();
-	      if (t != tok_colon)
-		{
-		  complain (_("ill-formed rule: initial symbol not followed by colon"));
-		  unlex (t);
-		}
-	    }
-
-	  if (nrules == 0 && t == tok_bar)
-	    {
-	      complain (_("grammar starts with vertical bar"));
-	      lhs = symval;	/* BOGUS: use a random symval */
-	    }
-	  /* start a new rule and record its lhs.  */
-
-	  nrules++;
-	  nitems++;
-
-	  p = symbol_list_new (lhs);
-
-	  crule1 = p1;
-	  if (p1)
-	    p1->next = p;
-	  else
-	    grammar = p;
-
-	  p1 = p;
-	  crule = p;
-
-	  /* mark the rule's lhs as a nonterminal if not already so.  */
-
-	  if (lhs->class == unknown_sym)
-	    {
-	      lhs->class = nterm_sym;
-	      lhs->value = nvars;
-	      nvars++;
-	    }
-	  else if (lhs->class == token_sym)
-	    complain (_("rule given for %s, which is a token"), lhs->tag);
+    if (t == tok_identifier || t == tok_bar)
+      {
+	int action_flag = 0;
+	/* Number of symbols in rhs of this rule so far */
+	int rulelength = 0;
+	int xactions = 0;	/* JF for error checking */
+	bucket *first_rhs = 0;
+
+	if (t == tok_identifier)
+	  {
+	    lhs = symval;
+
+	    if (!start_flag)
+	      {
+		startval = lhs;
+		start_flag = 1;
+	      }
 
-	  /* read the rhs of the rule.  */
+	    t = lex ();
+	    if (t != tok_colon)
+	      {
+		complain (_("ill-formed rule: initial symbol not followed by colon"));
+		unlex (t);
+	      }
+	  }
+
+	if (nrules == 0 && t == tok_bar)
+	  {
+	    complain (_("grammar starts with vertical bar"));
+	    lhs = symval;	/* BOGUS: use a random symval */
+	  }
+	/* start a new rule and record its lhs.  */
+
+	nrules++;
+	nitems++;
+
+	p = symbol_list_new (lhs);
+
+	crule1 = p1;
+	if (p1)
+	  p1->next = p;
+	else
+	  grammar = p;
 
-	  for (;;)
-	    {
-	      t = lex ();
-	      if (t == tok_prec)
-		{
-		  t = lex ();
-		  crule->ruleprec = symval;
-		  t = lex ();
-		}
+	p1 = p;
+	crule = p;
 
-	      if (!(t == tok_identifier || t == tok_left_curly))
-		break;
+	/* mark the rule's lhs as a nonterminal if not already so.  */
 
-	      /* If next token is an identifier, see if a colon follows it.
-	         If one does, exit this rule now.  */
-	      if (t == tok_identifier)
-		{
-		  bucket *ssave;
-		  token_t t1;
-
-		  ssave = symval;
-		  t1 = lex ();
-		  unlex (t1);
-		  symval = ssave;
-		  if (t1 == tok_colon)
-		    break;
-
-		  if (!first_rhs)	/* JF */
-		    first_rhs = symval;
-		  /* Not followed by colon =>
-		     process as part of this rule's rhs.  */
-		}
+	if (lhs->class == unknown_sym)
+	  {
+	    lhs->class = nterm_sym;
+	    lhs->value = nvars;
+	    nvars++;
+	  }
+	else if (lhs->class == token_sym)
+	  complain (_("rule given for %s, which is a token"), lhs->tag);
 
-	      /* If we just passed an action, that action was in the middle
-	         of a rule, so make a dummy rule to reduce it to a
-	         non-terminal.  */
-	      if (action_flag)
-		{
-		  /* Since the action was written out with this rule's
-		     number, we must give the new rule this number by
-		     inserting the new rule before it.  */
-
-		  /* Make a dummy nonterminal, a gensym.  */
-		  bucket *sdummy = gensym ();
-
-		  /* Make a new rule, whose body is empty, before the
-		     current one, so that the action just read can
-		     belong to it.  */
-		  nrules++;
-		  nitems++;
-		  p = symbol_list_new (sdummy);
-		  /* Attach its lineno to that of the host rule. */
-		  p->line = crule->line;
-		  if (crule1)
-		    crule1->next = p;
-		  else
-		    grammar = p;
-		  /* End of the rule. */
-		  crule1 = symbol_list_new (NULL);
-		  crule1->next = crule;
-
-		  p->next = crule1;
-
-		  /* Insert the dummy generated by that rule into this
-		     rule.  */
-		  nitems++;
-		  p = symbol_list_new (sdummy);
-		  p1->next = p;
-		  p1 = p;
-
-		  action_flag = 0;
-		}
+	/* read the rhs of the rule.  */
 
-	      if (t == tok_identifier)
-		{
-		  nitems++;
-		  p = symbol_list_new (symval);
-		  p1->next = p;
-		  p1 = p;
-		}
-	      else		/* handle an action.  */
-		{
-		  copy_action (crule, rulelength);
-		  action_flag = 1;
-		  xactions++;	/* JF */
-		}
-	      rulelength++;
-	    }			/* end of  read rhs of rule */
+	for (;;)
+	  {
+	    t = lex ();
+	    if (t == tok_prec)
+	      {
+		t = lex ();
+		crule->ruleprec = symval;
+		t = lex ();
+	      }
+
+	    if (!(t == tok_identifier || t == tok_left_curly))
+	      break;
 
-	  /* Put an empty link in the list to mark the end of this rule  */
-	  p = symbol_list_new (NULL);
-	  p1->next = p;
-	  p1 = p;
+	    /* If next token is an identifier, see if a colon follows it.
+	       If one does, exit this rule now.  */
+	    if (t == tok_identifier)
+	      {
+		bucket *ssave;
+		token_t t1;
+
+		ssave = symval;
+		t1 = lex ();
+		unlex (t1);
+		symval = ssave;
+		if (t1 == tok_colon)
+		  break;
+
+		if (!first_rhs)	/* JF */
+		  first_rhs = symval;
+		/* Not followed by colon =>
+		   process as part of this rule's rhs.  */
+	      }
+
+	    /* If we just passed an action, that action was in the middle
+	       of a rule, so make a dummy rule to reduce it to a
+	       non-terminal.  */
+	    if (action_flag)
+	      {
+		/* Since the action was written out with this rule's
+		   number, we must give the new rule this number by
+		   inserting the new rule before it.  */
+
+		/* Make a dummy nonterminal, a gensym.  */
+		bucket *sdummy = gensym ();
+
+		/* Make a new rule, whose body is empty, before the
+		   current one, so that the action just read can
+		   belong to it.  */
+		nrules++;
+		nitems++;
+		p = symbol_list_new (sdummy);
+		/* Attach its lineno to that of the host rule. */
+		p->line = crule->line;
+		/* Move the action from the host rule to this one. */
+		p->action = crule->action;
+		p->action_line = crule->action_line;
+		crule->action = NULL;
+
+		if (crule1)
+		  crule1->next = p;
+		else
+		  grammar = p;
+		/* End of the rule. */
+		crule1 = symbol_list_new (NULL);
+		crule1->next = crule;
+
+		p->next = crule1;
+
+		/* Insert the dummy generated by that rule into this
+		   rule.  */
+		nitems++;
+		p = symbol_list_new (sdummy);
+		p1->next = p;
+		p1 = p;
+
+		action_flag = 0;
+	      }
+
+	    if (t == tok_identifier)
+	      {
+		nitems++;
+		p = symbol_list_new (symval);
+		p1->next = p;
+		p1 = p;
+	      }
+	    else		/* handle an action.  */
+	      {
+		parse_action (crule, rulelength);
+		action_flag = 1;
+		xactions++;	/* JF */
+	      }
+	    rulelength++;
+	  }			/* end of  read rhs of rule */
+
+	/* Put an empty link in the list to mark the end of this rule  */
+	p = symbol_list_new (NULL);
+	p1->next = p;
+	p1 = p;
+
+	if (t == tok_prec)
+	  {
+	    complain (_("two @prec's in a row"));
+	    t = lex ();
+	    crule->ruleprec = symval;
+	    t = lex ();
+	  }
 
-	  if (t == tok_prec)
-	    {
-	      complain (_("two @prec's in a row"));
-	      t = lex ();
-	      crule->ruleprec = symval;
-	      t = lex ();
-	    }
-	  if (t == tok_guard)
-	    {
-	      if (!semantic_parser)
-		complain (_("%%guard present but %%semantic_parser not specified"));
+	if (t == tok_guard)
+	  {
+	    if (!semantic_parser)
+	      complain (_("%%guard present but %%semantic_parser not specified"));
 
-	      copy_guard (crule, rulelength);
-	      t = lex ();
-	    }
-	  else if (t == tok_left_curly)
-	    {
-	      /* This case never occurs -wjh */
-	      if (action_flag)
-		complain (_("two actions at end of one rule"));
-	      copy_action (crule, rulelength);
-	      action_flag = 1;
-	      xactions++;	/* -wjh */
-	      t = lex ();
-	    }
-	  /* If $$ is being set in default way, report if any type
-	     mismatch.  */
-	  else if (!xactions
-		   && first_rhs && lhs->type_name != first_rhs->type_name)
-	    {
-	      if (lhs->type_name == 0
-		  || first_rhs->type_name == 0
-		  || strcmp (lhs->type_name, first_rhs->type_name))
-		complain (_("type clash (`%s' `%s') on default action"),
-			  lhs->type_name ? lhs->type_name : "",
-			  first_rhs->type_name ? first_rhs->type_name : "");
-	    }
-	  /* Warn if there is no default for $$ but we need one.  */
-	  else if (!xactions && !first_rhs && lhs->type_name != 0)
-	    complain (_("empty rule for typed nonterminal, and no action"));
-	  if (t == tok_semicolon)
+	    parse_guard (crule, rulelength);
 	    t = lex ();
-	}
-#if 0
-      /* these things can appear as alternatives to rules.  */
-/* NO, they cannot.
-	a) none of the documentation allows them
-	b) most of them scan forward until finding a next %
-		thus they may swallow lots of intervening rules
-*/
-      else if (t == tok_token)
-	{
-	  parse_token_decl (token_sym, nterm_sym);
-	  t = lex ();
-	}
-      else if (t == tok_nterm)
-	{
-	  parse_token_decl (nterm_sym, token_sym);
-	  t = lex ();
-	}
-      else if (t == tok_type)
-	{
-	  t = get_type ();
-	}
-      else if (t == tok_union)
-	{
-	  parse_union_decl ();
-	  t = lex ();
-	}
-      else if (t == tok_expect)
-	{
-	  parse_expect_decl ();
-	  t = lex ();
-	}
-      else if (t == tok_start)
-	{
-	  parse_start_decl ();
-	  t = lex ();
-	}
-#endif
-
-      else
-	{
-	  complain (_("invalid input: %s"), quote (token_buffer));
+	  }
+
+	if (t == tok_left_curly)
+	  {
+	    /* This case never occurs -wjh */
+	    if (action_flag)
+	      complain (_("two actions at end of one rule"));
+	    parse_action (crule, rulelength);
+	    action_flag = 1;
+	    xactions++;	/* -wjh */
+	    t = lex ();
+	  }
+	/* If $$ is being set in default way, report if any type
+	   mismatch.  */
+	else if (!xactions
+		 && first_rhs && lhs->type_name != first_rhs->type_name)
+	  {
+	    if (lhs->type_name == 0
+		|| first_rhs->type_name == 0
+		|| strcmp (lhs->type_name, first_rhs->type_name))
+	      complain (_("type clash (`%s' `%s') on default action"),
+			lhs->type_name ? lhs->type_name : "",
+			first_rhs->type_name ? first_rhs->type_name : "");
+	  }
+	/* Warn if there is no default for $$ but we need one.  */
+	else if (!xactions && !first_rhs && lhs->type_name != 0)
+	  complain (_("empty rule for typed nonterminal, and no action"));
+	if (t == tok_semicolon)
 	  t = lex ();
-	}
-    }
+      }
+    else
+      {
+	complain (_("invalid input: %s"), quote (token_buffer));
+	t = lex ();
+      }
 
   /* grammar has been read.  Do some checking */
 
-  if (nsyms > MAXSHORT)
-    fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
-	   MAXSHORT);
   if (nrules == 0)
     fatal (_("no rules in the input grammar"));
 
@@ -1677,6 +1468,25 @@ readgram (void)
 	bp->value = nvars++;
       }
 
+  /* Insert the initial rule, which line is that of the first rule
+     (not that of the start symbol):
+
+     axiom: %start EOF.  */
+  p = symbol_list_new (axiom);
+  p->line = grammar->line;
+  p->next = symbol_list_new (startval);
+  p->next->next = symbol_list_new (eoftoken);
+  p->next->next->next = symbol_list_new (NULL);
+  p->next->next->next->next = grammar;
+  nrules += 1;
+  nitems += 3;
+  grammar = p;
+  startval = axiom;
+
+  if (nsyms > MAXSHORT)
+    fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
+	   MAXSHORT);
+
   ntokens = nsyms - nvars;
 }
 
@@ -1691,6 +1501,13 @@ read_additionnal_code (void)
 
   obstack_init (&el_obstack);
 
+  if (!no_lines_flag)
+    {
+      obstack_fgrow2 (&el_obstack, muscle_find ("linef"),
+		      lineno, quotearg_style (c_quoting_style,
+					      muscle_find ("filename")));
+    }
+
   while ((c = getc (finput)) != EOF)
     obstack_1grow (&el_obstack, c);
 
@@ -1699,55 +1516,6 @@ read_additionnal_code (void)
 }
 
 
-/*--------------------------------------------------------------.
-| For named tokens, but not literal ones, define the name.  The |
-| value is the user token number.                               |
-`--------------------------------------------------------------*/
-
-static void
-output_token_defines (struct obstack *oout)
-{
-  bucket *bp;
-  char *cp, *symbol;
-  char c;
-
-  for (bp = firstsymbol; bp; bp = bp->next)
-    {
-      symbol = bp->tag;		/* get symbol */
-
-      if (bp->value >= ntokens)
-	continue;
-      if (bp->user_token_number == SALIAS)
-	continue;
-      if ('\'' == *symbol)
-	continue;		/* skip literal character */
-      if (bp == errtoken)
-	continue;		/* skip error token */
-      if ('\"' == *symbol)
-	{
-	  /* use literal string only if given a symbol with an alias */
-	  if (bp->alias)
-	    symbol = bp->alias->tag;
-	  else
-	    continue;
-	}
-
-      /* Don't #define nonliteral tokens whose names contain periods.  */
-      cp = symbol;
-      while ((c = *cp++) && c != '.');
-      if (c != '\0')
-	continue;
-
-      obstack_fgrow2 (oout, "# define\t%s\t%d\n",
-		      symbol, bp->user_token_number);
-      if (semantic_parser)
-	/* FIXME: This is certainly dead wrong, and should be just as
-	   above. --akim.  */
-	obstack_fgrow2 (oout, "# define\tT%s\t%d\n", symbol, bp->value);
-    }
-}
-
-
 /*------------------------------------------------------------------.
 | Set TOKEN_TRANSLATIONS.  Check that no two symbols share the same |
 | number.                                                           |
@@ -1781,18 +1549,17 @@ token_translations_init (void)
       /* A token which translation has already been set? */
       if (token_translations[bp->user_token_number] != 2)
 	complain (_("tokens %s and %s both assigned number %d"),
-		  tags[token_translations[bp->user_token_number]],
+		  symbols[token_translations[bp->user_token_number]]->tag,
 		  bp->tag, bp->user_token_number);
       token_translations[bp->user_token_number] = bp->value;
     }
 }
 
 
-/*------------------------------------------------------------------.
-| Assign symbol numbers, and write definition of token names into   |
-| FDEFINES.  Set up vectors TAGS and SPREC of names and precedences |
-| of symbols.                                                       |
-`------------------------------------------------------------------*/
+/*----------------------------------------------------------------.
+| Assign symbol numbers, and write definition of token names into |
+| FDEFINES.  Set up vectors SYMBOL_TABLE, TAGS of symbols.        |
+`----------------------------------------------------------------*/
 
 static void
 packsymbols (void)
@@ -1800,17 +1567,8 @@ packsymbols (void)
   bucket *bp = NULL;
   int tokno = 1;
   int last_user_token_number;
-  static char DOLLAR[] = "$";
-
-  tags = XCALLOC (char *, nsyms + 1);
-  user_toknums = XCALLOC (short, nsyms + 1);
 
-  sprec = XCALLOC (short, nsyms);
-  sassoc = XCALLOC (short, nsyms);
-
-  /* The EOF token. */
-  tags[0] = DOLLAR;
-  user_toknums[0] = 0;
+  symbols = XCALLOC (bucket *, nsyms);
 
   max_user_token_number = 256;
   last_user_token_number = 256;
@@ -1823,11 +1581,18 @@ packsymbols (void)
 	}
       else if (bp->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 (bp->value == 0)
-	    bp->value = bp->alias->value = tokno++;
+	  /* 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 (bp->value == -1)
+	    {
+	      if (bp == eoftoken || bp->alias == eoftoken)
+		bp->value = bp->alias->value = 0;
+	      else
+		{
+		  bp->value = bp->alias->value = tokno++;
+		}
+	    }
 
 	  if (bp->prec != bp->alias->prec)
 	    {
@@ -1853,13 +1618,17 @@ packsymbols (void)
 		bp->assoc = bp->alias->assoc;
 	    }
 
+	  /* Do not do processing below for SALIASs.  */
 	  if (bp->user_token_number == SALIAS)
-	    continue;		/* do not do processing below for SALIASs */
+	    continue;
 
 	}
-      else			/* bp->class == token_sym */
+      else /* bp->class == token_sym */
 	{
-	  bp->value = tokno++;
+	  if (bp == eoftoken)
+	    bp->value = 0;
+	  else
+	    bp->value = tokno++;
 	}
 
       if (bp->class == token_sym)
@@ -1870,10 +1639,7 @@ packsymbols (void)
 	    max_user_token_number = bp->user_token_number;
 	}
 
-      tags[bp->value] = bp->tag;
-      user_toknums[bp->value] = bp->user_token_number;
-      sprec[bp->value] = bp->prec;
-      sassoc[bp->value] = bp->assoc;
+      symbols[bp->value] = bp;
     }
 
   token_translations_init ();
@@ -1889,63 +1655,6 @@ packsymbols (void)
 }
 
 
-/*-----------------------------------.
-| Output definition of token names.  |
-`-----------------------------------*/
-
-static void
-symbols_output (void)
-{
-  {
-    struct obstack tokendefs;
-    obstack_init (&tokendefs);
-    output_token_defines (&tokendefs);
-    obstack_1grow (&tokendefs, 0);
-    muscle_insert ("tokendef", xstrdup (obstack_finish (&tokendefs)));
-    obstack_free (&tokendefs, NULL);
-  }
-
-#if 0
-  if (!no_parser_flag)
-    output_token_defines (&table_obstack);
-#endif
-
-  if (defines_flag)
-    {
-      output_token_defines (&defines_obstack);
-
-      if (!pure_parser)
-	{
-	  if (spec_name_prefix)
-	    obstack_fgrow1 (&defines_obstack, "\nextern YYSTYPE %slval;\n",
-			    spec_name_prefix);
-	  else
-	    obstack_sgrow (&defines_obstack,
-				 "\nextern YYSTYPE yylval;\n");
-	}
-
-      if (semantic_parser)
-	{
-	  int i;
-
-	  for (i = ntokens; i < nsyms; i++)
-	    {
-	      /* don't make these for dummy nonterminals made by gensym.  */
-	      if (*tags[i] != '@')
-		obstack_fgrow2 (&defines_obstack,
-				"# define\tNT%s\t%d\n", tags[i], i);
-	    }
-#if 0
-	  /* `fdefines' is now a temporary file, so we need to copy its
-	     contents in `done', so we can't close it here.  */
-	  fclose (fdefines);
-	  fdefines = NULL;
-#endif
-	}
-    }
-}
-
-
 /*---------------------------------------------------------------.
 | Convert the rules into the representation using RRHS, RLHS and |
 | RITEMS.                                                        |
@@ -1958,8 +1667,12 @@ packgram (void)
   int ruleno;
   symbol_list *p;
 
+  /* We use short to index items.  */
+  if (nitems >= MAXSHORT)
+    fatal (_("too many items (max %d)"), MAXSHORT);
+
   ritem = XCALLOC (short, nitems + 1);
-  rule_table = XCALLOC (rule_t, nrules) - 1;
+  rules = XCALLOC (rule_t, nrules) - 1;
 
   itemno = 0;
   ruleno = 1;
@@ -1968,10 +1681,14 @@ packgram (void)
   while (p)
     {
       bucket *ruleprec = p->ruleprec;
-      rule_table[ruleno].lhs = p->sym->value;
-      rule_table[ruleno].rhs = itemno;
-      rule_table[ruleno].line = p->line;
-      rule_table[ruleno].useful = TRUE;
+      rules[ruleno].lhs = p->sym->value;
+      rules[ruleno].rhs = itemno;
+      rules[ruleno].line = p->line;
+      rules[ruleno].useful = TRUE;
+      rules[ruleno].action = p->action;
+      rules[ruleno].action_line = p->action_line;
+      rules[ruleno].guard = p->guard;
+      rules[ruleno].guard_line = p->guard_line;
 
       p = p->next;
       while (p && p->sym)
@@ -1981,8 +1698,8 @@ packgram (void)
 	     of the last token in it.  */
 	  if (p->sym->class == token_sym)
 	    {
-	      rule_table[ruleno].prec = p->sym->prec;
-	      rule_table[ruleno].assoc = p->sym->assoc;
+	      rules[ruleno].prec = p->sym->prec;
+	      rules[ruleno].assoc = p->sym->assoc;
 	    }
 	  if (p)
 	    p = p->next;
@@ -1992,9 +1709,9 @@ packgram (void)
          the specified symbol's precedence replaces the default.  */
       if (ruleprec)
 	{
-	  rule_table[ruleno].prec = ruleprec->prec;
-	  rule_table[ruleno].assoc = ruleprec->assoc;
-	  rule_table[ruleno].precsym = ruleprec->value;
+	  rules[ruleno].prec = ruleprec->prec;
+	  rules[ruleno].assoc = ruleprec->assoc;
+	  rules[ruleno].precsym = ruleprec->value;
 	}
 
       ritem[itemno++] = -ruleno;
@@ -2005,6 +1722,8 @@ packgram (void)
     }
 
   ritem[itemno] = 0;
+  nritems = itemno;
+  assert (nritems == nitems);
 
   if (trace_flag)
     ritem_print (stderr);
@@ -2024,7 +1743,7 @@ reader (void)
   start_flag = 0;
   startval = NULL;		/* start symbol not specified yet. */
 
-  nsyms = 1;
+  nsyms = 0;
   nvars = 0;
   nrules = 0;
   nitems = 0;
@@ -2046,6 +1765,11 @@ reader (void)
   /* Initialize the symbol table.  */
   tabinit ();
 
+  /* Construct the axiom symbol. */
+  axiom = getsym ("$axiom");
+  axiom->class = nterm_sym;
+  axiom->value = nvars++;
+
   /* Construct the error token */
   errtoken = getsym ("error");
   errtoken->class = token_sym;
@@ -2057,26 +1781,43 @@ reader (void)
   undeftoken->class = token_sym;
   undeftoken->user_token_number = 2;
 
+  /* Initialize the obstacks. */
+  obstack_init (&action_obstack);
+  obstack_init (&attrs_obstack);
+  obstack_init (&output_obstack);
+
+  finput = xfopen (infile, "r");
+
   /* Read the declaration section.  Copy %{ ... %} groups to
      TABLE_OBSTACK and FDEFINES file.  Also notice any %token, %left,
      etc. found there.  */
   read_declarations ();
+
+  /* If the user did not define her EOFTOKEN, do it now. */
+  if (!eoftoken)
+    {
+      eoftoken = getsym ("$");
+      eoftoken->class = token_sym;
+      /* Value specified by POSIX.  */
+      eoftoken->user_token_number = 0;
+    }
+
   /* Read in the grammar, build grammar in list form.  Write out
      guards and actions.  */
   readgram ();
   /* Some C code is given at the end of the grammar file. */
   read_additionnal_code ();
 
-  /* Now we know whether we need the line-number stack.  If we do,
-     write its type into the .tab.h file.
-     This is no longer need with header skeleton.  */
+  lex_free ();
+  xfclose (finput);
 
   /* Assign the symbols their symbol numbers.  Write #defines for the
      token symbols into FDEFINES if requested.  */
   packsymbols ();
-  symbols_output ();
+
   /* Convert the grammar into the format described in gram.h.  */
   packgram ();
-  /* Output the headers. */
-  symbols_output ();
+
+  /* The grammar as a symbol_list is no longer needed. */
+  LIST_FREE (symbol_list, grammar);
 }