build: include <config.h> from lib/yyerror.c

[bison.git] / src / reader.c

diff --git a/src/reader.c b/src/reader.c
index 6dd53f07233c1c3c038b411415cfe5ee41625438..942e8cfc5d2c63c7e423902d72d50af2deb61e37 100644 (file)
--- a/src/reader.c
+++ b/src/reader.c
@@ -1,1408 +1,489 @@
-/* Input parser for bison
-   Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002
-   Free Software Foundation, Inc.
+/* Input parser for Bison
+
+   Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000-2003, 2005-2007,
+   2009-2012 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
+   This program is free software: you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by
    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.
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.

 
 

-   Bison is distributed in the hope that it will be useful,
+   This program 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
    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.  */
-
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 
 

+#include <config.h>

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

-#include "quotearg.h"
-#include "quote.h"
-#include "getargs.h"
+
+#include <quote.h>
+#include <quotearg.h>
+
+#include "complain.h"
+#include "conflicts.h"

 #include "files.h"
 #include "files.h"

-#include "symtab.h"
-#include "options.h"
-#include "lex.h"
+#include "getargs.h"

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

-#include "complain.h"
-#include "output.h"
+#include "muscle-tab.h"

 #include "reader.h"
 #include "reader.h"

-#include "conflicts.h"
-#include "muscle_tab.h"
-
-typedef struct symbol_list
-{
-  struct symbol_list *next;
-  symbol_t *sym;
-  int line;
-
-  /* The action is attached to the LHS of a rule. */
-  const char *action;
-  int action_line;
+#include "symlist.h"
+#include "symtab.h"
+#include "scan-gram.h"
+#include "scan-code.h"

 
 

-  symbol_t *ruleprec;
-} symbol_list;
+static void prepare_percent_define_front_end_variables (void);
+static void check_and_convert_grammar (void);

 
 

-int lineno;

 static symbol_list *grammar = NULL;
 static symbol_list *grammar = NULL;

-static int start_flag = 0;
+static bool start_flag = false;
+merger_list *merge_functions;

 
 

-/* Nonzero if %union has been seen.  */
-static int typed = 0;
+/* Was %union seen?  */
+bool union_seen = false;

 
 

-/* Incremented for each %left, %right or %nonassoc seen */
-static int lastprec = 0;
+/* Was a tag seen?  */
+bool tag_seen = false;

 
 

-static symbol_list *
-symbol_list_new (symbol_t *sym)
-{
-  symbol_list *res = XMALLOC (symbol_list, 1);
-  res->next = NULL;
-  res->sym = sym;
-  res->line = lineno;
-  res->action = NULL;
-  res->action_line = 0;
-  res->ruleprec = NULL;
-  return res;
-}
-
-/*===================\
-| Low level lexing.  |
-\===================*/
+/* Should rules have a default precedence?  */
+bool default_prec = true;
+\f
+/*-----------------------.
+| Set the start symbol.  |
+`-----------------------*/

 
 

-static void
-skip_to_char (int target)
+void
+grammar_start_symbol_set (symbol *sym, location loc)

 {
 {

-  int c;
-  if (target == '\n')
-    complain (_("   Skipping to next \\n"));
+  if (start_flag)
+    complain_at (loc, _("multiple %s declarations"), "%start");

   else
   else

-    complain (_("   Skipping to next %c"), target);
-
-  do
-    c = skip_white_space ();
-  while (c != target && c != EOF);
-  if (c != EOF)
-    ungetc (c, finput);
-}
-
-
-/*---------------------------------------------------------.
-| Read a signed integer from STREAM and return its value.  |
-`---------------------------------------------------------*/
-
-static inline int
-read_signed_integer (FILE *stream)
-{
-  int c = getc (stream);
-  int sign = 1;
-  int n = 0;
-
-  if (c == '-')

     {
     {

-      c = getc (stream);
-      sign = -1;
+      start_flag = true;
+      startsymbol = sym;
+      startsymbol_location = loc;

     }
     }

-
-  while (isdigit (c))
-    {
-      n = 10 * n + (c - '0');
-      c = getc (stream);
-    }
-
-  ungetc (c, stream);
-
-  return sign * n;

 }
 }

-\f
-/*--------------------------------------------------------------.
-| Get the data type (alternative in the union) of the value for |
-| symbol N in rule RULE.                                        |
-`--------------------------------------------------------------*/
-
-static char *
-get_type_name (int n, symbol_list *rule)
-{
-  int i;
-  symbol_list *rp;
-
-  if (n < 0)
-    {
-      complain (_("invalid $ value"));
-      return NULL;
-    }
-
-  rp = rule;
-  i = 0;

 
 

-  while (i < n)
-    {
-      rp = rp->next;
-      if (rp == NULL || rp->sym == NULL)
-       {
-         complain (_("invalid $ value"));
-         return NULL;
-       }
-      ++i;
-    }
-
-  return rp->sym->type_name;
-}

 \f
 \f

-/*------------------------------------------------------------------.
-| Copy the character C to OOUT, and insert quadigraphs when needed. |
-`------------------------------------------------------------------*/

 
 

-static inline void
-copy_character (struct obstack *oout, int c)
-{
-  switch (c)
-    {
-    case '[':
-      obstack_sgrow (oout, "@<:@");
-      break;
+/*------------------------------------------------------------------------.
+| Return the merger index for a merging function named NAME.  Records the |
+| function, if new, in MERGER_LIST.                                       |
+`------------------------------------------------------------------------*/

 
 

-    case ']':
-      obstack_sgrow (oout, "@:>@");
-      break;
-
-    default:
-      obstack_1grow (oout, c);
-    }
-}
-
-/*------------------------------------------------------------.
-| Dump the string from FIN to OOUT if non null.  MATCH is the |
-| delimiter of the string (either ' or ").                    |
-`------------------------------------------------------------*/
-
-static inline void
-copy_string2 (FILE *fin, struct obstack *oout, int match, int store)
+static int
+get_merge_function (uniqstr name)

 {
 {

-  int c;
-
-  if (store)
-    obstack_1grow (oout, match);
+  merger_list *syms;
+  merger_list head;
+  int n;

 
 

-  c = getc (fin);
+  if (! glr_parser)
+    return 0;

 
 

-  while (c != match)
+  head.next = merge_functions;
+  for (syms = &head, n = 1; syms->next; syms = syms->next, n += 1)
+    if (UNIQSTR_EQ (name, syms->next->name))
+      break;
+  if (syms->next == NULL)

     {
     {

-      if (c == EOF)
-       fatal (_("unterminated string at end of file"));
-      if (c == '\n')
-       {
-         complain (_("unterminated string"));
-         ungetc (c, fin);
-         c = match;            /* invent terminator */
-         continue;
-       }
-
-      copy_character (oout, c);
-
-      if (c == '\\')
-       {
-         c = getc (fin);
-         if (c == EOF)
-           fatal (_("unterminated string at end of file"));
-         copy_character (oout, c);
-
-         if (c == '\n')
-           ++lineno;
-       }
-
-      c = getc (fin);
+      syms->next = xmalloc (sizeof syms->next[0]);
+      syms->next->name = uniqstr_new (name);
+      /* After all symbol type declarations have been parsed, packgram invokes
+        record_merge_function_type to set the type.  */
+      syms->next->type = NULL;
+      syms->next->next = NULL;
+      merge_functions = head.next;

     }
     }

-
-  if (store)
-    obstack_1grow (oout, c);
+  return n;

 }
 
 }
 

-/* FIXME. */
+/*-------------------------------------------------------------------------.
+| For the existing merging function with index MERGER, record the result   |
+| type as TYPE as required by the lhs of the rule whose %merge declaration |
+| is at DECLARATION_LOC.                                                   |
+`-------------------------------------------------------------------------*/

 
 

-static inline void
-copy_string (FILE *fin, struct obstack *oout, int match)
-{
-  copy_string2 (fin, oout, match, 1);
-}
-
-/* FIXME. */
-
-static inline void
-copy_identifier (FILE *fin, struct obstack *oout)
-{
-  int c;
-
-  while (isalnum (c = getc (fin)) || c == '_')
-    obstack_1grow (oout, c);
-
-  ungetc (c, fin);
-}
-
-
-/*------------------------------------------------------------------.
-| 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_comment (FILE *fin, struct obstack *oout)
+static void
+record_merge_function_type (int merger, uniqstr type, location declaration_loc)

 {
 {

-  int cplus_comment;
-  int ended;
-  int c;
+  int merger_find;
+  merger_list *merge_function;

 
 

-  /* We read a `/', output it. */
-  obstack_1grow (oout, '/');
-
-  switch ((c = getc (fin)))
-    {
-    case '/':
-      cplus_comment = 1;
-      break;
-    case '*':
-      cplus_comment = 0;
-      break;
-    default:
-      ungetc (c, fin);
-      return;
-    }
+  if (merger <= 0)
+    return;

 
 

-  obstack_1grow (oout, c);
-  c = getc (fin);
+  if (type == NULL)
+    type = uniqstr_new ("");

 
 

-  ended = 0;
-  while (!ended)
+  merger_find = 1;
+  for (merge_function = merge_functions;
+       merge_function != NULL && merger_find != merger;
+       merge_function = merge_function->next)
+    merger_find += 1;
+  aver (merge_function != NULL && merger_find == merger);
+  if (merge_function->type != NULL && !UNIQSTR_EQ (merge_function->type, type))

     {
     {

-      if (!cplus_comment && c == '*')
-       {
-         while (c == '*')
-           {
-             obstack_1grow (oout, c);
-             c = getc (fin);
-           }
-
-         if (c == '/')
-           {
-             obstack_1grow (oout, c);
-             ended = 1;
-           }
-       }
-      else if (c == '\n')
-       {
-         ++lineno;
-         obstack_1grow (oout, c);
-         if (cplus_comment)
-           ended = 1;
-         else
-           c = getc (fin);
-       }
-      else if (c == EOF)
-       fatal (_("unterminated comment"));
-      else
-       {
-         copy_character (oout, c);
-         c = getc (fin);
-       }
+      complain_at (declaration_loc,
+                  _("result type clash on merge function `%s': <%s> != <%s>"),
+                  merge_function->name, type, merge_function->type);
+      complain_at (merge_function->type_declaration_location,
+                  _("previous declaration"));

     }
     }

+  merge_function->type = uniqstr_new (type);
+  merge_function->type_declaration_location = declaration_loc;

 }
 
 }
 

+/*--------------------------------------.
+| Free all merge-function definitions. |
+`--------------------------------------*/

 
 

-/*-------------------------------------------------------------------.
-| FIN is pointing to a location (i.e., a `@').  Output to OOUT a     |
-| reference to this location. RULE_LENGTH 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.                                   |
-`-------------------------------------------------------------------*/
-
-static inline void
-copy_at (FILE *fin, struct obstack *oout, int rule_length)
+void
+free_merger_functions (void)

 {
 {

-  int c = getc (fin);
-  locations_flag = 1;
-
-  if (c == '$')
+  merger_list *L0 = merge_functions;
+  while (L0)

     {
     {

-      obstack_sgrow (oout, "]b4_lhs_location[");
-    }
-  else if (isdigit (c) || c == '-')
-    {
-      int n;
-
-      ungetc (c, fin);
-      n = read_signed_integer (fin);
-      if (n > rule_length)
-       complain (_("invalid value: %s%d"), "@", n);
-      else
-       obstack_fgrow2 (oout, "]b4_rhs_location([%d], [%d])[",
-                       rule_length, n);
-    }
-  else
-    {
-      char buf[] = "@c";
-      buf[1] = c;
-      complain (_("%s is invalid"), quote (buf));
+      merger_list *L1 = L0->next;
+      free (L0);
+      L0 = L1;

     }
 }
 
     }
 }
 

-
-/*------------------------------------------------------------------.
-| FIN is pointing to a wannabee semantic value (i.e., a `$').       |
-|                                                                   |
-| Possible inputs: $[<TYPENAME>]($|integer)                         |
-|                                                                   |
-| Output to OOUT a reference to this semantic value. RULE_LENGTH is |
-| the number of values in the current rule so far, which says where |
-| to find `$0' with respect to the top of the stack.                |
-`------------------------------------------------------------------*/
-
-static inline void
-copy_dollar (FILE *fin, struct obstack *oout,
-            symbol_list *rule, int rule_length)
-{
-  int c = getc (fin);
-  const char *type_name = NULL;
-
-  /* Get the type name if explicit. */
-  if (c == '<')
-    {
-      read_type_name (fin);
-      type_name = token_buffer;
-      c = getc (fin);
-    }
-
-  if (c == '$')
-    {
-      if (!type_name)
-       type_name = get_type_name (0, rule);
-      if (!type_name && typed)
-       complain (_("$$ of `%s' has no declared type"),
-                 rule->sym->tag);
-      if (!type_name)
-       type_name = "";
-      obstack_fgrow1 (oout,
-                     "]b4_lhs_value([%s])[", type_name);
-    }
-  else if (isdigit (c) || c == '-')
-    {
-      int n;
-      ungetc (c, fin);
-      n = read_signed_integer (fin);
-
-      if (n > rule_length)
-       complain (_("invalid value: %s%d"), "$", n);
-      else
-       {
-         if (!type_name && n > 0)
-           type_name = get_type_name (n, rule);
-         if (!type_name && typed)
-           complain (_("$%d of `%s' has no declared type"),
-                     n, rule->sym->tag);
-         if (!type_name)
-           type_name = "";
-         obstack_fgrow3 (oout, "]b4_rhs_value([%d], [%d], [%s])[",
-                         rule_length, n, type_name);
-       }
-    }
-  else
-    {
-      char buf[] = "$c";
-      buf[1] = c;
-      complain (_("%s is invalid"), quote (buf));
-    }
-}

 \f
 /*-------------------------------------------------------------------.
 \f
 /*-------------------------------------------------------------------.

-| Copy the contents of a `%{ ... %}' into the definitions file.  The |
-| `%{' has already been read.  Return after reading the `%}'.        |
+| 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 actions are copied out, labelled by the rule number they apply |
+| to.                                                                |

 `-------------------------------------------------------------------*/
 
 `-------------------------------------------------------------------*/
 

-static void
-copy_definition (struct obstack *oout)
-{
-  int c;
-  /* -1 while reading a character if prev char was %. */
-  int after_percent;
-
-  if (!no_lines_flag)
-    {
-      obstack_fgrow2 (oout, muscle_find ("linef"),
-                     lineno, quotearg_style (c_quoting_style,
-                                             muscle_find ("filename")));
-    }
-
-  after_percent = 0;
-
-  c = getc (finput);
-
-  for (;;)
-    {
-      switch (c)
-       {
-       case '\n':
-         obstack_1grow (oout, c);
-         ++lineno;
-         break;
-
-       case '%':
-         after_percent = -1;
-         break;
-
-       case '\'':
-       case '"':
-         copy_string (finput, oout, c);
-         break;
-
-       case '/':
-         copy_comment (finput, oout);
-         break;
-
-       case EOF:
-         fatal ("%s", _("unterminated `%{' definition"));
-
-       default:
-         copy_character (oout, c);
-       }
-
-      c = getc (finput);
-
-      if (after_percent)
-       {
-         if (c == '}')
-           return;
-         obstack_1grow (oout, '%');
-       }
-      after_percent = 0;
-    }
-}
-
-
-/*------------------------------------------.
-| Parse what comes after %token or %nterm.  |
-`------------------------------------------*/
+/* The (currently) last symbol of GRAMMAR. */
+static symbol_list *grammar_end = NULL;

 
 

-static void
-parse_token_decl (symbol_class class)
+/* Append SYM to the grammar.  */
+static symbol_list *
+grammar_symbol_append (symbol *sym, location loc)

 {
 {

-  token_t token = tok_undef;
-  char *typename = NULL;
-
-  /* The symbol being defined.  */
-  symbol_t *symbol = NULL;
+  symbol_list *p = symbol_list_sym_new (sym, loc);

 
 

-  /* After `%token' and `%nterm', any number of symbols maybe be
-     defined.  */
-  for (;;)
-    {
-      int tmp_char = ungetc (skip_white_space (), finput);
-
-      /* `%' (for instance from `%token', or from `%%' etc.) is the
-        only valid means to end this declaration.  */
-      if (tmp_char == '%')
-       return;
-      if (tmp_char == EOF)
-       fatal (_("Premature EOF after %s"), token_buffer);
-
-      token = lex ();
-      switch (token)
-       {
-       case tok_comma:
-         symbol = NULL;
-         break;
-
-       case tok_typename:
-         typename = xstrdup (token_buffer);
-         symbol = NULL;
-         break;
-
-       case tok_identifier:
-         if (*symval->tag == '\"' && symbol)
-           {
-             symbol_make_alias (symbol, symval, typename);
-             symbol = NULL;
-           }
-         else
-           {
-             symbol = symval;
-             symbol_class_set (symbol, class);
-             if (typename)
-               symbol_type_set (symbol, typename);
-           }
-         break;
-
-       case tok_number:
-         symbol_user_token_number_set (symbol, numval);
-         break;
-
-       default:
-         complain (_("`%s' is invalid in %s"),
-                   token_buffer,
-                   (class == token_sym) ? "%token" : "%nterm");
-         skip_to_char ('%');
-       }
-    }
-
-}
-
-
-/*------------------------------.
-| Parse what comes after %start |
-`------------------------------*/
-
-static void
-parse_start_decl (void)
-{
-  if (start_flag)
-    complain (_("multiple %s declarations"), "%start");
-  if (lex () != tok_identifier)
-    complain (_("invalid %s declaration"), "%start");
+  if (grammar_end)
+    grammar_end->next = p;

   else
   else

-    {
-      start_flag = 1;
-      startsymbol = symval;
-    }
-}
-
-/*-----------------------------------------------------------.
-| read in a %type declaration and record its information for |
-| get_type_name to access                                    |
-`-----------------------------------------------------------*/
-
-static void
-parse_type_decl (void)
-{
-  char *name;
-
-  if (lex () != tok_typename)
-    {
-      complain ("%s", _("%type declaration has no <typename>"));
-      skip_to_char ('%');
-      return;
-    }
-
-  name = xstrdup (token_buffer);
-
-  for (;;)
-    {
-      token_t t;
-      int tmp_char = ungetc (skip_white_space (), finput);
+    grammar = p;

 
 

-      if (tmp_char == '%')
-       return;
-      if (tmp_char == EOF)
-       fatal (_("Premature EOF after %s"), token_buffer);
+  grammar_end = p;

 
 

-      t = lex ();
+  /* A null SYM stands for an end of rule; it is not an actual
+     part of it.  */
+  if (sym)
+    ++nritems;

 
 

-      switch (t)
-       {
-       case tok_comma:
-       case tok_semicolon:
-         break;
-
-       case tok_identifier:
-         symbol_type_set (symval, name);
-         break;
-
-       default:
-         complain (_("invalid %%type declaration due to item: %s"),
-                   token_buffer);
-         skip_to_char ('%');
-       }
-    }
+  return p;

 }
 
 }
 

-
-
-/*----------------------------------------------------------------.
-| Read in a %left, %right or %nonassoc declaration and record its |
-| information.                                                    |
-`----------------------------------------------------------------*/
-

 static void
 static void

-parse_assoc_decl (associativity assoc)
+assign_named_ref (symbol_list *p, named_ref *name)

 {
 {

-  char *name = NULL;
-  int prev = 0;
-
-  /* Assign a new precedence level, never 0.  */
-  ++lastprec;
+  symbol *sym = p->content.sym;

 
 

-  for (;;)
+  if (name->id == sym->tag)

     {
     {

-      token_t t;
-      int tmp_char = ungetc (skip_white_space (), finput);
-
-      if (tmp_char == '%')
-       return;
-      if (tmp_char == EOF)
-       fatal (_("Premature EOF after %s"), token_buffer);
-
-      t = lex ();
-
-      switch (t)
-       {
-       case tok_typename:
-         name = xstrdup (token_buffer);
-         break;
-
-       case tok_comma:
-         break;
-
-       case tok_identifier:
-         symbol_class_set (symval, token_sym);
-         symbol_precedence_set (symval, lastprec, assoc);
-         if (name)
-           symbol_type_set (symval, name);
-         break;
-
-       case tok_number:
-         if (prev == tok_identifier)
-           {
-             symbol_user_token_number_set (symval, numval);
-           }
-         else
-           {
-             complain
-               (_("invalid text (%s) - number should be after identifier"),
-                token_buffer);
-             skip_to_char ('%');
-           }
-         break;
-
-       case tok_semicolon:
-         return;
-
-       default:
-         complain (_("unexpected item: %s"), token_buffer);
-         skip_to_char ('%');
-       }
-
-      prev = t;
+      warn_at (name->loc,
+              _("duplicated symbol name for %s ignored"),
+              quote (sym->tag));
+      named_ref_free (name);

     }
     }

+  else
+    p->named_ref = name;

 }
 
 
 }
 
 

-
-/*--------------------------------------------------------------.
-| Copy the union declaration into the stype muscle             |
-| (and fdefines),  where it is made into the definition of     |
-| YYSTYPE, the type of elements of the parser value stack.     |
-`--------------------------------------------------------------*/
-
-static void
-parse_union_decl (void)
-{
-  int c;
-  int count = 0;
-  bool done = FALSE;
-  struct obstack union_obstack;
-  if (typed)
-    complain (_("multiple %s declarations"), "%union");
-
-  typed = 1;
-
-  MUSCLE_INSERT_INT ("stype_line", lineno);
-  obstack_init (&union_obstack);
-  obstack_sgrow (&union_obstack, "union");
-
-  while (!done)
-    {
-      c = xgetc (finput);
-
-      /* If C contains '/', it is output by copy_comment ().  */
-      if (c != '/')
-       obstack_1grow (&union_obstack, c);
-
-      switch (c)
-       {
-       case '\n':
-         ++lineno;
-         break;
-
-       case '/':
-         copy_comment (finput, &union_obstack);
-         break;
-
-       case '{':
-         ++count;
-         break;
-
-       case '}':
-         /* FIXME: Errr.  How could this happen???. --akim */
-         if (count == 0)
-           complain (_("unmatched %s"), "`}'");
-         count--;
-         if (!count)
-           done = TRUE;
-         break;
-       }
-    }
-
-  /* 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));
-}
+/* The rule currently being defined, and the previous rule.
+   CURRENT_RULE points to the first LHS of the current rule, while
+   PREVIOUS_RULE_END points to the *end* of the previous rule (NULL).  */
+static symbol_list *current_rule = NULL;
+static symbol_list *previous_rule_end = NULL;

 
 
 
 

-/*-------------------------------------------------------.
-| Parse the declaration %expect N which says to expect N |
-| shift-reduce conflicts.                                |
-`-------------------------------------------------------*/
+/*----------------------------------------------.
+| Create a new rule for LHS in to the GRAMMAR.  |
+`----------------------------------------------*/

 
 

-static void
-parse_expect_decl (void)
+void
+grammar_current_rule_begin (symbol *lhs, location loc,
+                           named_ref *lhs_name)

 {
 {

-  int c = skip_white_space ();
-  ungetc (c, finput);
-
-  if (!isdigit (c))
-    complain (_("argument of %%expect is not an integer"));
-  else
-    expected_conflicts = read_signed_integer (finput);
-}
+  symbol_list* p;

 
 

+  /* Start a new rule and record its lhs.  */
+  ++nrules;
+  previous_rule_end = grammar_end;

 
 

-static void
-parse_muscle_decl (void)
-{
-  int ch = ungetc (skip_white_space (), finput);
-  char *muscle_key;
-  char *muscle_value;
+  p = grammar_symbol_append (lhs, loc);
+  if (lhs_name)
+    assign_named_ref (p, named_ref_copy (lhs_name));

 
 

-  /* Read key. */
-  if (!isalpha (ch) && ch != '_')
-    {
-      complain (_("invalid %s declaration"), "%define");
-      skip_to_char ('%');
-      return;
-    }
-  copy_identifier (finput, &muscle_obstack);
-  obstack_1grow (&muscle_obstack, 0);
-  muscle_key = obstack_finish (&muscle_obstack);
+  current_rule = grammar_end;

 
 

-  /* Read value. */
-  ch = skip_white_space ();
-  if (ch != '"')
+  /* Mark the rule's lhs as a nonterminal if not already so.  */
+  if (lhs->class == unknown_sym)

     {
     {

-      ungetc (ch, finput);
-      if (ch != EOF)
-       {
-         complain (_("invalid %s declaration"), "%define");
-         skip_to_char ('%');
-         return;
-       }
-      else
-       fatal (_("Premature EOF after %s"), "\"");
+      lhs->class = nterm_sym;
+      lhs->number = nvars;
+      ++nvars;

     }
     }

-  copy_string2 (finput, &muscle_obstack, '"', 0);
-  obstack_1grow (&muscle_obstack, 0);
-  muscle_value = obstack_finish (&muscle_obstack);
-
-  /* Store the (key, value) pair in the environment. */
-  muscle_insert (muscle_key, muscle_value);
+  else if (lhs->class == token_sym)
+    complain_at (loc, _("rule given for %s, which is a token"), lhs->tag);

 }
 
 
 }
 
 

+/*----------------------------------------------------------------------.
+| A symbol should be used if either:                                    |
+|   1. It has a destructor.                                             |
+|   2. The symbol is a mid-rule symbol (i.e., the generated LHS         |
+|      replacing a mid-rule action) that was assigned to or used, as in |
+|      "exp: { $$ = 1; } { $$ = $1; }".                                 |
+`----------------------------------------------------------------------*/

 
 

-/*---------------------------------.
-| Parse a double quoted parameter. |
-`---------------------------------*/
-
-static const char *
-parse_dquoted_param (const char *from)
+static bool
+symbol_should_be_used (symbol_list const *s, bool *midrule_warning)

 {
 {

-  struct obstack param_obstack;
-  const char *param = NULL;
-  int c;
-
-  obstack_init (&param_obstack);
-  c = skip_white_space ();
-
-  if (c != '"')
-    {
-      complain (_("invalid %s declaration"), from);
-      ungetc (c, finput);
-      skip_to_char ('%');
-      return NULL;
-    }
-
-  while ((c = literalchar ()) != '"')
-    obstack_1grow (&param_obstack, c);
-
-  obstack_1grow (&param_obstack, '\0');
-  param = obstack_finish (&param_obstack);
-
-  if (c != '"' || strlen (param) == 0)
+  if (symbol_destructor_get (s->content.sym)->code)
+    return true;
+  if ((s->midrule && s->midrule->action_props.is_value_used)
+      || (s->midrule_parent_rule
+          && symbol_list_n_get (s->midrule_parent_rule,
+                                s->midrule_parent_rhs_index)
+               ->action_props.is_value_used))

     {
     {

-      complain (_("invalid %s declaration"), from);
-      if (c != '"')
-       ungetc (c, finput);
-      skip_to_char ('%');
-      return NULL;
+      *midrule_warning = true;
+      return true;

     }
     }

-
-  return param;
-}
-
-/*----------------------------------.
-| Parse what comes after %skeleton. |
-`----------------------------------*/
-
-static void
-parse_skel_decl (void)
-{
-  skeleton = parse_dquoted_param ("%skeleton");
+  return false;

 }
 
 /*----------------------------------------------------------------.
 }
 
 /*----------------------------------------------------------------.

-| Read from finput until `%%' is seen.  Discard the `%%'.  Handle |
-| any `%' declarations, and copy the contents of any `%{ ... %}'  |
-| groups to PRE_PROLOGUE_OBSTACK or POST_PROLOGUE_OBSTACK.        |
+| Check that the rule R is properly defined.  For instance, there |
+| should be no type clash on the default action.                  |

 `----------------------------------------------------------------*/
 
 static void
 `----------------------------------------------------------------*/
 
 static void

-read_declarations (void)
+grammar_rule_check (const symbol_list *r)

 {
 {

-  for (;;)
-    {
-      int c = skip_white_space ();
+  /* Type check.
+
+     If there is an action, then there is nothing we can do: the user
+     is allowed to shoot herself in the foot.

 
 

-      if (c == '%')
+     Don't worry about the default action if $$ is untyped, since $$'s
+     value can't be used.  */
+  if (!r->action_props.code && r->content.sym->type_name)
+    {
+      symbol *first_rhs = r->next->content.sym;
+      /* If $$ is being set in default way, report if any type mismatch.  */
+      if (first_rhs)

        {
        {

-         token_t tok = parse_percent_token ();
-
-         switch (tok)
-           {
-           case tok_two_percents:
-             return;
-
-           case tok_percent_left_curly:
-              if (!typed)
-               copy_definition (&pre_prologue_obstack);
-             else
-               copy_definition (&post_prologue_obstack);
-             break;
-
-           case tok_token:
-             parse_token_decl (token_sym);
-             break;
-
-           case tok_nterm:
-             parse_token_decl (nterm_sym);
-             break;
-
-           case tok_type:
-             parse_type_decl ();
-             break;
-
-           case tok_start:
-             parse_start_decl ();
-             break;
-
-           case tok_union:
-             parse_union_decl ();
-             break;
-
-           case tok_expect:
-             parse_expect_decl ();
-             break;
-
-           case tok_left:
-             parse_assoc_decl (left_assoc);
-             break;
-
-           case tok_right:
-             parse_assoc_decl (right_assoc);
-             break;
-
-           case tok_nonassoc:
-             parse_assoc_decl (non_assoc);
-             break;
-
-           case tok_define:
-             parse_muscle_decl ();
-             break;
-
-           case tok_skel:
-             parse_skel_decl ();
-             break;
-
-           case tok_noop:
-             break;
-
-           case tok_stropt:
-           case tok_intopt:
-           case tok_obsolete:
-             assert (0);
-             break;
-
-           case tok_illegal:
-           default:
-             complain (_("unrecognized: %s"), token_buffer);
-             skip_to_char ('%');
-           }
+         char const *lhs_type = r->content.sym->type_name;
+         const char *rhs_type =
+           first_rhs->type_name ? first_rhs->type_name : "";
+         if (!UNIQSTR_EQ (lhs_type, rhs_type))
+           warn_at (r->location,
+                    _("type clash on default action: <%s> != <%s>"),
+                    lhs_type, rhs_type);

        }
        }

-      else if (c == EOF)
-       fatal (_("no input grammar"));
+      /* Warn if there is no default for $$ but we need one.  */

       else
       else

-       {
-         char buf[] = "c";
-         buf[0] = c;
-         complain (_("unknown character: %s"), quote (buf));
-         skip_to_char ('%');
-       }
+       warn_at (r->location,
+                _("empty rule for typed nonterminal, and no action"));

     }
     }

-}
-\f
-/*------------------------------------------------------------------.
-| Assuming that a `{' has just been seen, copy everything up to the |
-| matching `}' into ACTION_OBSTACK, and return a pointer to this    |
-| action.                                                           |
-`------------------------------------------------------------------*/

 
 

-static char *
-parse_action (symbol_list *rule)
-{
-  int count = 1;
-
-  /* RULE_LENGTH is the number of values in the current rule so far,
-     which says where to find `$0' with respect to the top of the
-     stack.  It is not the same as the rule->length in the case of mid
-     rule actions.  */
-  int rule_length = 0;
-  symbol_list *rhs;
-  for (rhs = rule->next; rhs; rhs = rhs->next)
-    ++rule_length;
-
-  while (count > 0)
-    {
-      int c;
-      while ((c = getc (finput)) != '}')
-       switch (c)
-         {
-         case '\n':
-           copy_character (&action_obstack, c);
-           ++lineno;
-           break;
-
-         case '{':
-           copy_character (&action_obstack, c);
-           ++count;
-           break;
-
-         case '\'':
-         case '"':
-           copy_string (finput, &action_obstack, c);
-           break;
-
-         case '/':
-           copy_comment (finput, &action_obstack);
-           break;
-
-         case '$':
-           copy_dollar (finput, &action_obstack, rule, rule_length);
-           break;
-
-         case '@':
-           copy_at (finput, &action_obstack, rule_length);
-           break;
-
-         case EOF:
-           fatal (_("unmatched %s"), "`{'");
-
-         default:
-           copy_character (&action_obstack, c);
-         }
-
-      /* Above loop exits when C is '}'.  */
-      if (--count)
-       copy_character (&action_obstack, c);
-    }
+  /* Check that symbol values that should be used are in fact used.  */
+  {
+    symbol_list const *l = r;
+    int n = 0;
+    for (; l && l->content.sym; l = l->next, ++n)
+      {
+        bool midrule_warning = false;
+        if (!l->action_props.is_value_used
+            && symbol_should_be_used (l, &midrule_warning)
+            /* The default action, $$ = $1, `uses' both.  */
+            && (r->action_props.code || (n != 0 && n != 1)))
+          {
+            void (*warn_at_ptr)(location, char const*, ...) =
+              midrule_warning ? midrule_value_at : warn_at;
+            if (n)
+              warn_at_ptr (r->location, _("unused value: $%d"), n);
+            else
+              warn_at_ptr (r->location, _("unset value: $$"));
+          }
+      }
+  }

 
 

-  obstack_1grow (&action_obstack, '\0');
-  return obstack_finish (&action_obstack);
+  /* See comments in grammar_current_rule_prec_set for how POSIX
+     mandates this complaint.  It's only for identifiers, so skip
+     it for char literals and strings, which are always tokens.  */
+  if (r->ruleprec
+      && r->ruleprec->tag[0] != '\'' && r->ruleprec->tag[0] != '"'
+      && !r->ruleprec->declared && !r->ruleprec->prec)
+    warn_at (r->location, _("token for %%prec is not defined: %s"),
+             r->ruleprec->tag);

 }
 
 }
 

-\f

 
 

-/*-------------------------------------------------------------------.
-| Generate a dummy symbol, a nonterminal, whose name cannot conflict |
-| with the user's names.                                             |
-`-------------------------------------------------------------------*/
+/*-------------------------------------.
+| End the currently being grown rule.  |
+`-------------------------------------*/

 
 

-static symbol_t *
-gensym (void)
+void
+grammar_current_rule_end (location loc)

 {
 {

-  /* Incremented for each generated symbol */
-  static int gensym_count = 0;
-  static char buf[256];
-
-  symbol_t *sym;
-
-  sprintf (buf, "@%d", ++gensym_count);
-  token_buffer = buf;
-  sym = getsym (token_buffer);
-  sym->class = nterm_sym;
-  sym->number = nvars++;
-  return sym;
+  /* Put an empty link in the list to mark the end of this rule  */
+  grammar_symbol_append (NULL, grammar_end->location);
+  current_rule->location = loc;

 }
 }

-\f
-/*-------------------------------------------------------------------.
-| 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 actions are copied out, 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.                                              |
-`-------------------------------------------------------------------*/
-
-/* The (currently) last symbol of GRAMMAR. */
-symbol_list *grammar_end = NULL;
-
-/* Append S to the GRAMMAR. */
-static void
-grammar_symbol_append (symbol_t *s)
-{
-  symbol_list *p = symbol_list_new (s);
-
-  if (grammar_end)
-    grammar_end->next = p;
-  else
-    grammar = p;

 
 

-  grammar_end = p;
-}
-
-/* The rule currently being defined, and the previous rule.  Point to
-   the first symbol of each list: their lhs.  */
-symbol_list *current_rule = NULL;
-symbol_list *previous_rule = NULL;
-
-
-/* Create a new rule for LHS in to the GRAMMAR. */
-
-static void
-grammar_rule_begin (symbol_t *lhs)
-{
-  if (!start_flag)
-    {
-      startsymbol = lhs;
-      start_flag = 1;
-    }
-
-  /* Start a new rule and record its lhs.  */
-  ++nrules;
-  ++nritems;
-
-  previous_rule = grammar_end;
-  grammar_symbol_append (lhs);
-  current_rule = grammar_end;
-
-  /* Mark the rule's lhs as a nonterminal if not already so.  */
-
-  if (lhs->class == unknown_sym)
-    {
-      lhs->class = nterm_sym;
-      lhs->number = nvars;
-      ++nvars;
-    }
-  else if (lhs->class == token_sym)
-    complain (_("rule given for %s, which is a token"), lhs->tag);
-}

 
 

-/* The previous action turns out the be a mid-rule action.  Attach it
-   to the current rule, i.e., create a dummy symbol, attach it this
-   mid-rule action, and append this dummy nonterminal to the current
-   rule.  */
+/*-------------------------------------------------------------------.
+| The previous action turns out the be a mid-rule action.  Attach it |
+| to the current rule, i.e., create a dummy symbol, attach it this   |
+| mid-rule action, and append this dummy nonterminal to the current  |
+| rule.                                                              |
+`-------------------------------------------------------------------*/

 
 

-static void
+void

 grammar_midrule_action (void)
 {
   /* 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.  */
 
 grammar_midrule_action (void)
 {
   /* 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.  */
-  symbol_t *sdummy = gensym ();
-  symbol_list *midrule_action = symbol_list_new (sdummy);
+  /* Make a DUMMY nonterminal, whose location is that of the midrule
+     action.  Create the MIDRULE.  */
+  location dummy_location = current_rule->action_props.location;
+  symbol *dummy = dummy_symbol_get (dummy_location);
+  symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location);
+
+  /* Remember named_ref of previous action. */
+  named_ref *action_name = current_rule->action_props.named_ref;

 
   /* Make a new rule, whose body is empty, before the current one, so
      that the action just read can belong to it.  */
   ++nrules;
   ++nritems;
 
   /* Make a new rule, whose body is empty, before the current one, so
      that the action just read can belong to it.  */
   ++nrules;
   ++nritems;

-  /* Attach its lineno to that of the host rule.  */
-  midrule_action->line = current_rule->line;
-  /* Move the action from the host rule to this one.  */
-  midrule_action->action = current_rule->action;
-  midrule_action->action_line = current_rule->action_line;
-  current_rule->action = NULL;
-
-  if (previous_rule)
-    previous_rule->next = midrule_action;
+  /* Attach its location and actions to that of the DUMMY.  */
+  midrule->location = dummy_location;
+  code_props_rule_action_init (&midrule->action_props,
+                               current_rule->action_props.code,
+                               current_rule->action_props.location,
+                               midrule, 0);
+  code_props_none_init (&current_rule->action_props);
+
+  if (previous_rule_end)
+    previous_rule_end->next = midrule;

   else
   else

-    grammar = midrule_action;
+    grammar = midrule;

 
 

-  /* End of the rule. */
-  previous_rule = symbol_list_new (NULL);
-  previous_rule->next = current_rule;
+  /* End the dummy's rule.  */
+  midrule->next = symbol_list_sym_new (NULL, dummy_location);
+  midrule->next->next = current_rule;

 
 

-  midrule_action->next = previous_rule;
+  previous_rule_end = midrule->next;

 
 

-  /* Insert the dummy generated by that rule into this rule.  */
-  ++nritems;
-  grammar_symbol_append (sdummy);
+  /* Insert the dummy nonterminal replacing the midrule action into
+     the current rule.  Bind it to its dedicated rule.  */
+  grammar_current_rule_symbol_append (dummy, dummy_location,
+                                      action_name);
+  grammar_end->midrule = midrule;
+  midrule->midrule_parent_rule = current_rule;
+  midrule->midrule_parent_rhs_index = symbol_list_length (current_rule->next);

 }
 
 /* Set the precedence symbol of the current rule to PRECSYM. */
 
 }
 
 /* Set the precedence symbol of the current rule to PRECSYM. */
 

-static void
-grammar_current_rule_prec_set (symbol_t *precsym)
-{
+void
+grammar_current_rule_prec_set (symbol *precsym, location loc)
+{
+  /* POSIX says that any identifier is a nonterminal if it does not
+     appear on the LHS of a grammar rule and is not defined by %token
+     or by one of the directives that assigns precedence to a token.  We
+     ignore this here because the only kind of identifier that POSIX
+     allows to follow a %prec is a token and because assuming it's a
+     token now can produce more logical error messages.  Nevertheless,
+     grammar_rule_check does obey what we believe is the real intent of
+     POSIX here: that an error be reported for any identifier that
+     appears after %prec but that is not defined separately as a
+     token.  */
+  symbol_class_set (precsym, token_sym, loc, false);

   if (current_rule->ruleprec)
   if (current_rule->ruleprec)

-    complain (_("two @prec's in a row"));
+    complain_at (loc, _("only one %s allowed per rule"), "%prec");

   current_rule->ruleprec = precsym;
 }
 
   current_rule->ruleprec = precsym;
 }
 

-/* Check that the last rule (CURRENT_RULE) is properly defined.  For
-   instance, there should be no type clash on the default action.  */
+/* Attach dynamic precedence DPREC to the current rule. */

 
 

-static void
-grammar_current_rule_check (void)
+void
+grammar_current_rule_dprec_set (int dprec, location loc)

 {
 {

-  symbol_t *lhs = current_rule->sym;
-  symbol_t *first_rhs = current_rule->next->sym;
-
-  /* If there is an action, then there is nothing we can do: the user
-     is allowed to shoot in her foot.  */
-  if (current_rule->action)
-    return;
-
-  /* If $$ is being set in default way, report if any type mismatch.
-     */
-  if (first_rhs)
-    {
-      const char *lhs_type = lhs->type_name       ? lhs->type_name       : "";
-      const char *rhs_type = first_rhs->type_name ? first_rhs->type_name : "";
-      if (strcmp (lhs_type, rhs_type))
-       complain (_("type clash (`%s' `%s') on default action"),
-                 lhs_type, rhs_type);
-    }
-  /* Warn if there is no default for $$ but we need one.  */
-  else
-    {
-      if (lhs->type_name)
-       complain (_("empty rule for typed nonterminal, and no action"));
-    }
+  if (! glr_parser)
+    warn_at (loc, _("%s affects only GLR parsers"), "%dprec");
+  if (dprec <= 0)
+    complain_at (loc, _("%s must be followed by positive number"), "%dprec");
+  else if (current_rule->dprec != 0)
+    complain_at (loc, _("only one %s allowed per rule"), "%dprec");
+  current_rule->dprec = dprec;

 }
 
 }
 

+/* Attach a merge function NAME with argument type TYPE to current
+   rule. */

 
 

-/* Attach a SYMBOL to the current rule.  If needed, move the previous
-   action as a mid-rule action.  */
-
-static void
-grammar_current_rule_symbol_append (symbol_t *symbol)
+void
+grammar_current_rule_merge_set (uniqstr name, location loc)

 {
 {

-  if (current_rule->action)
-    grammar_midrule_action ();
-  ++nritems;
-  grammar_symbol_append (symbol);
+  if (! glr_parser)
+    warn_at (loc, _("%s affects only GLR parsers"), "%merge");
+  if (current_rule->merger != 0)
+    complain_at (loc, _("only one %s allowed per rule"), "%merge");
+  current_rule->merger = get_merge_function (name);
+  current_rule->merger_declaration_location = loc;

 }
 
 }
 

-
-/* Attach an ACTION to the current rule.  If needed, move the previous
+/* Attach SYM to the current rule.  If needed, move the previous

    action as a mid-rule action.  */
 
    action as a mid-rule action.  */
 

-static void
-grammar_current_rule_action_append (char *action, int action_line)
+void
+grammar_current_rule_symbol_append (symbol *sym, location loc,
+                                   named_ref *name)

 {
 {

-  if (current_rule->action)
+  symbol_list *p;
+  if (current_rule->action_props.code)

     grammar_midrule_action ();
     grammar_midrule_action ();

-  current_rule->action = action;
-  current_rule->action_line = action_line;
+  p = grammar_symbol_append (sym, loc);
+  if (name)
+    assign_named_ref(p, name);

 }
 
 }
 

+/* Attach an ACTION to the current rule.  */

 
 

-
-static void
-readgram (void)
-{
-  token_t t;
-  symbol_t *lhs = NULL;
-
-  t = lex ();
-
-  while (t != tok_two_percents && t != tok_eof)
-    if (t == tok_identifier || t == tok_bar)
-      {
-       if (t == tok_identifier)
-         {
-           lhs = symval;
-
-           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 */
-         }
-
-       grammar_rule_begin (lhs);
-       /* read the rhs of the rule.  */
-
-       for (;;)
-         {
-           t = lex ();
-           if (t == tok_prec)
-             {
-               t = lex ();
-               grammar_current_rule_prec_set (symval);
-               t = lex ();
-             }
-
-           if (!(t == tok_identifier || t == tok_left_curly))
-             break;
-
-           /* If next token is an identifier, see if a colon follows it.
-              If one does, exit this rule now.  */
-           if (t == tok_identifier)
-             {
-               symbol_t *ssave;
-               token_t t1;
-
-               ssave = symval;
-               t1 = lex ();
-               unlex (t1);
-               symval = ssave;
-               if (t1 == tok_colon)
-                 {
-                   warn (_("previous rule lacks an ending `;'"));
-                   break;
-                 }
-               /* Not followed by colon => process as part of this
-                  rule's rhs.  */
-             }
-
-           if (t == tok_identifier)
-             {
-               grammar_current_rule_symbol_append (symval);
-             }
-           else                /* handle an action.  */
-             {
-               int action_line = lineno;
-               char *action = parse_action (current_rule);
-               grammar_current_rule_action_append (action, action_line);
-             }
-         }                     /* end of  read rhs of rule */
-
-       /* Put an empty link in the list to mark the end of this rule  */
-       grammar_symbol_append (NULL);
-
-       if (t == tok_prec)
-         {
-           t = lex ();
-           grammar_current_rule_prec_set (symval);
-           t = lex ();
-         }
-
-       if (t == tok_left_curly)
-         {
-           int action_line = lineno;
-           char *action = parse_action (current_rule);
-           grammar_current_rule_action_append (action, action_line);
-           t = lex ();
-         }
-
-       grammar_current_rule_check ();
-
-       if (t == tok_two_percents || t == tok_eof)
-         warn (_("previous rule lacks an ending `;'"));
-       if (t == tok_semicolon)
-         t = lex ();
-      }
-    else
-      {
-       complain (_("invalid input: %s"), quote (token_buffer));
-       t = lex ();
-      }
-
-  /* grammar has been read.  Do some checking */
-
-  if (nrules == 0)
-    fatal (_("no rules in the input grammar"));
-
-  /* Report any undefined symbols and consider them nonterminals.  */
-  symbols_check_defined ();
-
-  /* Insert the initial rule, which line is that of the first rule
-     (not that of the start symbol):
-
-     axiom: %start EOF.  */
-  {
-    symbol_list *p = symbol_list_new (axiom);
-    p->line = grammar->line;
-    p->next = symbol_list_new (startsymbol);
-    p->next->next = symbol_list_new (eoftoken);
-    p->next->next->next = symbol_list_new (NULL);
-    p->next->next->next->next = grammar;
-    nrules += 1;
-    nritems += 3;
-    grammar = p;
-  }
-
-  if (nsyms > SHRT_MAX)
-    fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
-          SHRT_MAX);
-
-  assert (nsyms == ntokens + nvars);
-}
-
-/* At the end of the grammar file, some C source code must
-   be stored. It is going to be associated to the epilogue
-   directive.  */
-static void
-read_additionnal_code (void)
+void
+grammar_current_rule_action_append (const char *action, location loc,
+                                   named_ref *name)

 {
 {

-  int c;
-  struct obstack el_obstack;
-
-  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)
-    copy_character (&el_obstack, c);
-
-  obstack_1grow (&el_obstack, 0);
-  muscle_insert ("epilogue", obstack_finish (&el_obstack));
+  if (current_rule->action_props.code)
+    grammar_midrule_action ();
+  /* After all symbol declarations have been parsed, packgram invokes
+     code_props_translate_code.  */
+  code_props_rule_action_init (&current_rule->action_props, action, loc,
+                               current_rule, name);

 }
 
 \f
 }
 
 \f


@@ -1414,41 +495,69 @@ read_additionnal_code (void)
 static void
 packgram (void)
 {
 static void
 packgram (void)
 {

-  unsigned int itemno;
-  int ruleno;
-  symbol_list *p;
+  unsigned int itemno = 0;
+  rule_number ruleno = 0;
+  symbol_list *p = grammar;

 
 

-  ritem = XCALLOC (item_number_t, nritems);
-  rules = XCALLOC (rule_t, nrules) - 1;
+  ritem = xnmalloc (nritems + 1, sizeof *ritem);

 
 

-  itemno = 0;
-  ruleno = 1;
+  /* This sentinel is used by build_relations in gram.c.  */
+  *ritem++ = 0;
+
+  rules = xnmalloc (nrules, sizeof *rules);

 
 

-  p = grammar;

   while (p)
     {
   while (p)
     {

-      symbol_t *ruleprec = p->ruleprec;
+      int rule_length = 0;
+      symbol *ruleprec = p->ruleprec;
+      record_merge_function_type (p->merger, p->content.sym->type_name,
+                                 p->merger_declaration_location);

       rules[ruleno].user_number = ruleno;
       rules[ruleno].number = ruleno;
       rules[ruleno].user_number = ruleno;
       rules[ruleno].number = ruleno;

-      rules[ruleno].lhs = p->sym;
+      rules[ruleno].lhs = p->content.sym;

       rules[ruleno].rhs = ritem + itemno;
       rules[ruleno].rhs = ritem + itemno;

-      rules[ruleno].line = p->line;
-      rules[ruleno].useful = TRUE;
-      rules[ruleno].action = p->action;
-      rules[ruleno].action_line = p->action_line;
-
-      p = p->next;
-      while (p && p->sym)
+      rules[ruleno].prec = NULL;
+      rules[ruleno].dprec = p->dprec;
+      rules[ruleno].merger = p->merger;
+      rules[ruleno].precsym = NULL;
+      rules[ruleno].location = p->location;
+      rules[ruleno].useful = true;
+      rules[ruleno].action = p->action_props.code;
+      rules[ruleno].action_location = p->action_props.location;
+
+      /* If the midrule's $$ is set or its $n is used, remove the `$' from the
+        symbol name so that it's a user-defined symbol so that the default
+        %destructor and %printer apply.  */
+      if (p->midrule_parent_rule
+          && (p->action_props.is_value_used
+             || symbol_list_n_get (p->midrule_parent_rule,
+                                   p->midrule_parent_rhs_index)
+                   ->action_props.is_value_used))
+       p->content.sym->tag += 1;
+
+      /* Don't check the generated rule 0.  It has no action, so some rhs
+        symbols may appear unused, but the parsing algorithm ensures that
+        %destructor's are invoked appropriately.  */
+      if (p != grammar)
+       grammar_rule_check (p);
+
+      for (p = p->next; p && p->content.sym; p = p->next)

        {
        {

-         /* item_number_t = symbol_number_t.
+         ++rule_length;
+
+         /* Don't allow rule_length == INT_MAX, since that might
+            cause confusion with strtol if INT_MAX == LONG_MAX.  */
+         if (rule_length == INT_MAX)
+             fatal_at (rules[ruleno].location, _("rule is too long"));
+
+         /* item_number = symbol_number.

             But the former needs to contain more: negative rule numbers. */
             But the former needs to contain more: negative rule numbers. */

-         ritem[itemno++] = symbol_number_as_item_number (p->sym->number);
+         ritem[itemno++] =
+            symbol_number_as_item_number (p->content.sym->number);

          /* A rule gets by default the precedence and associativity
          /* A rule gets by default the precedence and associativity

-            of the last token in it.  */
-         if (p->sym->class == token_sym)
-           rules[ruleno].prec = p->sym;
-         if (p)
-           p = p->next;
+            of its last token.  */
+         if (p->content.sym->class == token_sym && default_prec)
+           rules[ruleno].prec = p->content.sym;

        }
 
       /* If this rule has a %prec,
        }
 
       /* If this rule has a %prec,


@@ -1458,16 +567,19 @@ packgram (void)
          rules[ruleno].precsym = ruleprec;
          rules[ruleno].prec = ruleprec;
        }
          rules[ruleno].precsym = ruleprec;
          rules[ruleno].prec = ruleprec;
        }

-      ritem[itemno++] = -ruleno;
+      /* An item ends by the rule number (negated).  */
+      ritem[itemno++] = rule_number_as_item_number (ruleno);
+      aver (itemno < ITEM_NUMBER_MAX);

       ++ruleno;
       ++ruleno;

+      aver (ruleno < RULE_NUMBER_MAX);

 
       if (p)
        p = p->next;
     }
 
 
       if (p)
        p = p->next;
     }
 

-  assert (itemno == nritems);
+  aver (itemno == nritems);

 
 

-  if (trace_flag)
+  if (trace_flag & trace_sets)

     ritem_print (stderr);
 }
 \f
     ritem_print (stderr);
 }
 \f


@@ -1481,70 +593,154 @@ packgram (void)
 void
 reader (void)
 {
 void
 reader (void)
 {

-  lex_init ();
-  lineno = 1;
-
-  /* Initialize the muscle obstack.  */
-  obstack_init (&muscle_obstack);
-

   /* Initialize the symbol table.  */
   symbols_new ();
 
   /* Initialize the symbol table.  */
   symbols_new ();
 

-  /* Construct the axiom symbol. */
-  axiom = getsym ("$axiom");
-  axiom->class = nterm_sym;
-  axiom->number = nvars++;
+  /* Construct the accept symbol. */
+  accept = symbol_get ("$accept", empty_location);
+  accept->class = nterm_sym;
+  accept->number = nvars++;

 
   /* Construct the error token */
 
   /* Construct the error token */

-  errtoken = getsym ("error");
+  errtoken = symbol_get ("error", empty_location);

   errtoken->class = token_sym;
   errtoken->number = ntokens++;
 
   /* Construct a token that represents all undefined literal tokens.
      It is always token number 2.  */
   errtoken->class = token_sym;
   errtoken->number = ntokens++;
 
   /* Construct a token that represents all undefined literal tokens.
      It is always token number 2.  */

-  undeftoken = getsym ("$undefined.");
+  undeftoken = symbol_get ("$undefined", empty_location);

   undeftoken->class = token_sym;
   undeftoken->number = ntokens++;
 
   undeftoken->class = token_sym;
   undeftoken->number = ntokens++;
 

-  /* Initialize the obstacks. */
-  obstack_init (&action_obstack);
-  obstack_init (&output_obstack);
-  obstack_init (&pre_prologue_obstack);
-  obstack_init (&post_prologue_obstack);
+  gram_in = xfopen (grammar_file, "r");
+
+  gram__flex_debug = trace_flag & trace_scan;
+  gram_debug = trace_flag & trace_parse;
+  gram_scanner_initialize ();
+  gram_parse ();
+  prepare_percent_define_front_end_variables ();

 
 

-  finput = xfopen (infile, "r");
+  if (! complaint_issued)
+    check_and_convert_grammar ();

 
 

-  /* Read the declaration section.  Copy %{ ... %} groups to
-     TABLE_OBSTACK and FDEFINES file.  Also notice any %token, %left,
-     etc. found there.  */
-  read_declarations ();
+  xfclose (gram_in);
+}
+
+static void
+prepare_percent_define_front_end_variables (void)
+{
+  /* Set %define front-end variable defaults.  */
+  muscle_percent_define_default ("lr.keep-unreachable-states", "false");
+  {
+    char *lr_type;
+    /* IELR would be a better default, but LALR is historically the
+       default.  */
+    muscle_percent_define_default ("lr.type", "lalr");
+    lr_type = muscle_percent_define_get ("lr.type");
+    if (0 != strcmp (lr_type, "canonical-lr"))
+      muscle_percent_define_default ("lr.default-reductions", "most");
+    else
+      muscle_percent_define_default ("lr.default-reductions", "accepting");
+    free (lr_type);
+  }

 
 

-  /* If the user did not define her EOFTOKEN, do it now. */
-  if (!eoftoken)
+  /* Check %define front-end variables.  */
+  {
+    static char const * const values[] = {
+      "lr.type", "lalr", "ielr", "canonical-lr", NULL,
+      "lr.default-reductions", "most", "consistent", "accepting", NULL,
+      NULL
+    };
+    muscle_percent_define_check_values (values);
+  }
+}
+
+
+/*-------------------------------------------------------------.
+| Check the grammar that has just been read, and convert it to |
+| internal form.                                              |
+`-------------------------------------------------------------*/
+
+static void
+check_and_convert_grammar (void)
+{
+  /* Grammar has been read.  Do some checking.  */
+  if (nrules == 0)
+    fatal (_("no rules in the input grammar"));
+
+  /* If the user did not define her ENDTOKEN, do it now. */
+  if (!endtoken)

     {
     {

-      eoftoken = getsym ("$");
-      eoftoken->class = token_sym;
-      eoftoken->number = 0;
+      endtoken = symbol_get ("$end", empty_location);
+      endtoken->class = token_sym;
+      endtoken->number = 0;

       /* Value specified by POSIX.  */
       /* Value specified by POSIX.  */

-      eoftoken->user_token_number = 0;
+      endtoken->user_token_number = 0;

     }
 
     }
 

-  /* Read in the grammar, build grammar in list form.  Write out
-     actions.  */
-  readgram ();
-  /* Some C code is given at the end of the grammar file. */
-  read_additionnal_code ();
+  /* Report any undefined symbols and consider them nonterminals.  */
+  symbols_check_defined ();

 
 

-  lex_free ();
-  xfclose (finput);
+  /* Find the start symbol if no %start.  */
+  if (!start_flag)
+    {
+      symbol_list *node;
+      for (node = grammar;
+           node != NULL && symbol_is_dummy (node->content.sym);
+           node = node->next)
+        {
+          for (node = node->next;
+               node != NULL && node->content.sym != NULL;
+               node = node->next)
+            ;
+        }
+      aver (node != NULL);
+      grammar_start_symbol_set (node->content.sym,
+                                node->content.sym->location);
+    }
+
+  /* Insert the initial rule, whose line is that of the first rule
+     (not that of the start symbol):
+
+     accept: %start EOF.  */
+  {
+    symbol_list *p = symbol_list_sym_new (accept, empty_location);
+    p->location = grammar->location;
+    p->next = symbol_list_sym_new (startsymbol, empty_location);
+    p->next->next = symbol_list_sym_new (endtoken, empty_location);
+    p->next->next->next = symbol_list_sym_new (NULL, empty_location);
+    p->next->next->next->next = grammar;
+    nrules += 1;
+    nritems += 3;
+    grammar = p;
+  }
+
+  aver (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars);

 
   /* Assign the symbols their symbol numbers.  Write #defines for the
      token symbols into FDEFINES if requested.  */
   symbols_pack ();
 
 
   /* Assign the symbols their symbol numbers.  Write #defines for the
      token symbols into FDEFINES if requested.  */
   symbols_pack ();
 

+  /* Scan rule actions after invoking symbol_check_alias_consistency (in
+     symbols_pack above) so that token types are set correctly before the rule
+     action type checking.
+
+     Before invoking grammar_rule_check (in packgram below) on any rule, make
+     sure all actions have already been scanned in order to set `used' flags.
+     Otherwise, checking that a midrule's $$ should be set will not always work
+     properly because the check must forward-reference the midrule's parent
+     rule.  For the same reason, all the `used' flags must be set before
+     checking whether to remove `$' from any midrule symbol name (also in
+     packgram).  */
+  {
+    symbol_list *sym;
+    for (sym = grammar; sym; sym = sym->next)
+      code_props_translate_code (&sym->action_props);
+  }
+

   /* Convert the grammar into the format described in gram.h.  */
   packgram ();
 
   /* The grammar as a symbol_list is no longer needed. */
   /* Convert the grammar into the format described in gram.h.  */
   packgram ();
 
   /* The grammar as a symbol_list is no longer needed. */

-  LIST_FREE (symbol_list, grammar);
+  symbol_list_free (grammar);

 }
 }