glr: allow spaces between "%?" and "{" in predicates

[bison.git] / src / symtab.c

diff --git a/src/symtab.c b/src/symtab.c
index 1d0ed91f4bbbbfc9323c9f3e3c134cc2ab04e3a1..1c2372c12f05e7c75f7d79ea1daba4bb8e5766e1 100644 (file)
--- a/src/symtab.c
+++ b/src/symtab.c
@@ -1,6 +1,6 @@
 /* Symbol table manager for Bison.
 
 /* Symbol table manager for Bison.
 

-   Copyright (C) 1984, 1989, 2000-2002, 2004-2012 Free Software
+   Copyright (C) 1984, 1989, 2000-2002, 2004-2013 Free Software

    Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
    Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.


@@ -46,20 +46,17 @@ symbol *accept = NULL;
 symbol *startsymbol = NULL;
 location startsymbol_location;
 
 symbol *startsymbol = NULL;
 location startsymbol_location;
 

-/*---------------------------------------.
-| Default %destructor's and %printer's.  |
-`---------------------------------------*/
+/*---------------------------.
+| Precedence relation graph. |
+`---------------------------*/

 
 

-static code_props default_tagged_code_props[CODE_PROPS_SIZE] =
-  {
-    CODE_PROPS_NONE_INIT,
-    CODE_PROPS_NONE_INIT,
-  };
-static code_props default_tagless_code_props[CODE_PROPS_SIZE] =
-  {
-    CODE_PROPS_NONE_INIT,
-    CODE_PROPS_NONE_INIT,
-  };
+static symgraph **prec_nodes;
+
+/*-----------------------------------.
+| Store which associativity is used. |
+`-----------------------------------*/
+
+bool *used_assoc = NULL;

 
 /*---------------------------------.
 | Create a new symbol, named TAG.  |
 
 /*---------------------------------.
 | Create a new symbol, named TAG.  |


@@ -69,21 +66,23 @@ static symbol *
 symbol_new (uniqstr tag, location loc)
 {
   symbol *res = xmalloc (sizeof *res);
 symbol_new (uniqstr tag, location loc)
 {
   symbol *res = xmalloc (sizeof *res);

-

   uniqstr_assert (tag);
 
   /* If the tag is not a string (starts with a double quote), check
      that it is valid for Yacc. */
   if (tag[0] != '\"' && tag[0] != '\'' && strchr (tag, '-'))
   uniqstr_assert (tag);
 
   /* If the tag is not a string (starts with a double quote), check
      that it is valid for Yacc. */
   if (tag[0] != '\"' && tag[0] != '\'' && strchr (tag, '-'))

-    complain_at (loc, Wyacc,
-                 _("POSIX Yacc forbids dashes in symbol names: %s"), tag);
+    complain (&loc, Wyacc,
+              _("POSIX Yacc forbids dashes in symbol names: %s"), tag);

 
   res->tag = tag;
   res->location = loc;
 
   res->type_name = NULL;
 
   res->tag = tag;
   res->location = loc;
 
   res->type_name = NULL;

-  for (int i = 0; i < CODE_PROPS_SIZE; ++i)
-    code_props_none_init (&res->props[i]);
+  {
+    int i;
+    for (i = 0; i < CODE_PROPS_SIZE; ++i)
+      code_props_none_init (&res->props[i]);
+  }

 
   res->number = NUMBER_UNDEFINED;
   res->prec = 0;
 
   res->number = NUMBER_UNDEFINED;
   res->prec = 0;


@@ -95,7 +94,7 @@ symbol_new (uniqstr tag, location loc)
   res->status = undeclared;
 
   if (nsyms == SYMBOL_NUMBER_MAXIMUM)
   res->status = undeclared;
 
   if (nsyms == SYMBOL_NUMBER_MAXIMUM)

-    complain (fatal, _("too many symbols in input grammar (limit is %d)"),
+    complain (NULL, fatal, _("too many symbols in input grammar (limit is %d)"),

               SYMBOL_NUMBER_MAXIMUM);
   nsyms++;
   return res;
               SYMBOL_NUMBER_MAXIMUM);
   nsyms++;
   return res;


@@ -125,10 +124,13 @@ semantic_type_new (uniqstr tag, const location *loc)
 
   uniqstr_assert (tag);
   res->tag = tag;
 
   uniqstr_assert (tag);
   res->tag = tag;

-  if (loc)
-    res->location = *loc;
-  for (int i = 0; i < CODE_PROPS_SIZE; ++i)
-    code_props_none_init (&res->props[i]);
+  res->location = loc ? *loc : empty_location;
+  res->status = undeclared;
+  {
+    int i;
+    for (i = 0; i < CODE_PROPS_SIZE; ++i)
+      code_props_none_init (&res->props[i]);
+  }

 
   return res;
 }
 
   return res;
 }


@@ -147,17 +149,17 @@ semantic_type_new (uniqstr tag, const location *loc)
     fprintf (f, " %s { %s }", #Attr, s->props[Attr].code)
 
 void
     fprintf (f, " %s { %s }", #Attr, s->props[Attr].code)
 
 void

-symbol_print (symbol *s, FILE *f)
+symbol_print (symbol const *s, FILE *f)

 {
   if (s)
     {
 {
   if (s)
     {

-      fprintf (f, "\"%s\"", s->tag);
+      fputs (s->tag, f);

       SYMBOL_ATTR_PRINT (type_name);
       SYMBOL_CODE_PRINT (destructor);
       SYMBOL_CODE_PRINT (printer);
     }
   else
       SYMBOL_ATTR_PRINT (type_name);
       SYMBOL_CODE_PRINT (destructor);
       SYMBOL_CODE_PRINT (printer);
     }
   else

-    fprintf (f, "<NULL>");
+    fputs ("<NULL>", f);

 }
 
 #undef SYMBOL_ATTR_PRINT
 }
 
 #undef SYMBOL_ATTR_PRINT


@@ -207,16 +209,24 @@ static void
 symbol_redeclaration (symbol *s, const char *what, location first,
                       location second)
 {
 symbol_redeclaration (symbol *s, const char *what, location first,
                       location second)
 {

-  complain_at (second, complaint, _("%s redeclaration for %s"), what, s->tag);
-  complain_at (first, complaint, _("previous declaration"));
+  unsigned i = 0;
+  complain_indent (&second, complaint, &i,
+                   _("%s redeclaration for %s"), what, s->tag);
+  i += SUB_INDENT;
+  complain_indent (&first, complaint, &i,
+                   _("previous declaration"));

 }
 
 static void
 semantic_type_redeclaration (semantic_type *s, const char *what, location first,
                              location second)
 {
 }
 
 static void
 semantic_type_redeclaration (semantic_type *s, const char *what, location first,
                              location second)
 {

-  complain_at (second, complaint, _("%s redeclaration for <%s>"), what, s->tag);
-  complain_at (first, complaint, _("previous declaration"));
+  unsigned i = 0;
+  complain_indent (&second, complaint, &i,
+                   _("%s redeclaration for <%s>"), what, s->tag);
+  i += SUB_INDENT;
+  complain_indent (&first, complaint, &i,
+                   _("previous declaration"));

 }
 
 
 }
 
 


@@ -233,9 +243,12 @@ symbol_type_set (symbol *sym, uniqstr type_name, location loc)
     {
       if (sym->type_name)
         symbol_redeclaration (sym, "%type", sym->type_location, loc);
     {
       if (sym->type_name)
         symbol_redeclaration (sym, "%type", sym->type_location, loc);

-      uniqstr_assert (type_name);
-      sym->type_name = type_name;
-      sym->type_location = loc;
+      else
+        {
+          uniqstr_assert (type_name);
+          sym->type_name = type_name;
+          sym->type_location = loc;
+        }

     }
 }
 
     }
 }
 


@@ -251,7 +264,8 @@ symbol_code_props_set (symbol *sym, code_props_type kind,
     symbol_redeclaration (sym, code_props_type_string (kind),
                           sym->props[kind].location,
                           code->location);
     symbol_redeclaration (sym, code_props_type_string (kind),
                           sym->props[kind].location,
                           code->location);

-  sym->props[kind] = *code;
+  else
+    sym->props[kind] = *code;

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


@@ -267,16 +281,16 @@ semantic_type_code_props_set (semantic_type *type,
     semantic_type_redeclaration (type, code_props_type_string (kind),
                                  type->props[kind].location,
                                  code->location);
     semantic_type_redeclaration (type, code_props_type_string (kind),
                                  type->props[kind].location,
                                  code->location);

-  type->props[kind] = *code;
+  else
+    type->props[kind] = *code;

 }
 
 /*---------------------------------------------------.
 | Get the computed %destructor or %printer for SYM.  |
 `---------------------------------------------------*/
 
 }
 
 /*---------------------------------------------------.
 | Get the computed %destructor or %printer for SYM.  |
 `---------------------------------------------------*/
 

-code_props const *
-symbol_code_props_get (symbol const *sym,
-                       code_props_type kind)
+code_props *
+symbol_code_props_get (symbol *sym, code_props_type kind)

 {
   /* Per-symbol code props.  */
   if (sym->props[kind].code)
 {
   /* Per-symbol code props.  */
   if (sym->props[kind].code)


@@ -285,19 +299,21 @@ symbol_code_props_get (symbol const *sym,
   /* Per-type code props.  */
   if (sym->type_name)
     {
   /* Per-type code props.  */
   if (sym->type_name)
     {

-      code_props const *code =
+      code_props *code =

         &semantic_type_get (sym->type_name, NULL)->props[kind];
       if (code->code)
         return code;
     }
 
   /* Apply default code props's only to user-defined symbols.  */
         &semantic_type_get (sym->type_name, NULL)->props[kind];
       if (code->code)
         return code;
     }
 
   /* Apply default code props's only to user-defined symbols.  */

-  if (sym->tag[0] == '$' || sym == errtoken)
-    return &code_props_none;
-
-  if (sym->type_name)
-    return &default_tagged_code_props[kind];
-  return &default_tagless_code_props[kind];
+  if (sym->tag[0] != '$' && sym != errtoken)
+    {
+      code_props *code =
+        &semantic_type_get (sym->type_name ? "*" : "", NULL)->props[kind];
+      if (code->code)
+        return code;
+    }
+  return &code_props_none;

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


@@ -310,12 +326,15 @@ symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
 {
   if (a != undef_assoc)
     {
 {
   if (a != undef_assoc)
     {

-      if (sym->prec != 0)
+      if (sym->prec)

         symbol_redeclaration (sym, assoc_to_string (a), sym->prec_location,
                               loc);
         symbol_redeclaration (sym, assoc_to_string (a), sym->prec_location,
                               loc);

-      sym->prec = prec;
-      sym->assoc = a;
-      sym->prec_location = loc;
+      else
+        {
+          sym->prec = prec;
+          sym->assoc = a;
+          sym->prec_location = loc;
+        }

     }
 
   /* Only terminals have a precedence. */
     }
 
   /* Only terminals have a precedence. */


@@ -333,8 +352,8 @@ symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
   bool warned = false;
   if (sym->class != unknown_sym && sym->class != class)
     {
   bool warned = false;
   if (sym->class != unknown_sym && sym->class != class)
     {

-      complain_at (loc, complaint, _("symbol %s redefined"), sym->tag);
-      // Don't report both "redefined" and "redeclared".
+      complain (&loc, complaint, _("symbol %s redefined"), sym->tag);
+      /* Don't report both "redefined" and "redeclared".  */

       warned = true;
     }
 
       warned = true;
     }
 


@@ -348,8 +367,9 @@ symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
   if (declaring)
     {
       if (sym->status == declared && !warned)
   if (declaring)
     {
       if (sym->status == declared && !warned)

-        complain_at (loc, Wother, _("symbol %s redeclared"), sym->tag);
-      sym->status = declared;
+        complain (&loc, Wother, _("symbol %s redeclared"), sym->tag);
+      else
+        sym->status = declared;

     }
 }
 
     }
 }
 


@@ -369,8 +389,8 @@ symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
     user_token_numberp = &sym->alias->user_token_number;
   if (*user_token_numberp != USER_NUMBER_UNDEFINED
       && *user_token_numberp != user_token_number)
     user_token_numberp = &sym->alias->user_token_number;
   if (*user_token_numberp != USER_NUMBER_UNDEFINED
       && *user_token_numberp != user_token_number)

-    complain_at (loc, complaint, _("redefining user token number of %s"),
-                 sym->tag);
+    complain (&loc, complaint, _("redefining user token number of %s"),
+              sym->tag);

 
   *user_token_numberp = user_token_number;
   /* User defined $end token? */
 
   *user_token_numberp = user_token_number;
   /* User defined $end token? */


@@ -396,38 +416,21 @@ symbol_check_defined (symbol *sym)
 {
   if (sym->class == unknown_sym)
     {
 {
   if (sym->class == unknown_sym)
     {

-      switch (sym->status)
-        {
-        case used:
-          complain_at (sym->location, Wother,
-                   _("symbol %s is used, but is not defined as a token"
-                     " and has no rules"),
-                   sym->tag);
-          break;
-        case undeclared:
-        case needed:
-          complain_at (sym->location, complaint,
-                    _("symbol %s is used, but is not defined as a token"
-                      " and has no rules"),
-                    sym->tag);
-          break;
-        case declared:
-          /* If declared, then sym->class != unknown_sym. */
-          assert (0);
-        }
-
+      assert (sym->status != declared);
+      complain (&sym->location,
+                sym->status == needed ? complaint : Wother,
+                _("symbol %s is used, but is not defined as a token"
+                  " and has no rules"),
+                  sym->tag);

       sym->class = nterm_sym;
       sym->number = nvars++;
     }
 
       sym->class = nterm_sym;
       sym->number = nvars++;
     }
 

-  for (int i = 0; i < 2; ++i)
-    if (sym->props[i].kind == CODE_PROPS_NONE && sym->type_name)
-      {
-        semantic_type *sem_type = semantic_type_get (sym->type_name, NULL);
-        if (sem_type
-            && sem_type->props[i].kind != CODE_PROPS_NONE)
-          sem_type->props[i].is_used = true;
-      }
+  {
+    int i;
+    for (i = 0; i < 2; ++i)
+      symbol_code_props_get (sym, i)->is_used = true;
+  }

 
   /* Set the semantic type status associated to the current symbol to
      'declared' so that we could check semantic types unnecessary uses. */
 
   /* Set the semantic type status associated to the current symbol to
      'declared' so that we could check semantic types unnecessary uses. */


@@ -444,19 +447,23 @@ symbol_check_defined (symbol *sym)
 static inline bool
 semantic_type_check_defined (semantic_type *sem_type)
 {
 static inline bool
 semantic_type_check_defined (semantic_type *sem_type)
 {

-  if (sem_type->status == declared)
+  /* <*> and <> do not have to be "declared".  */
+  if (sem_type->status == declared
+      || !*sem_type->tag
+      || STREQ (sem_type->tag, "*"))

     {
     {

-      for (int i = 0; i < 2; ++i)
+      int i;
+      for (i = 0; i < 2; ++i)

         if (sem_type->props[i].kind != CODE_PROPS_NONE
             && ! sem_type->props[i].is_used)
         if (sem_type->props[i].kind != CODE_PROPS_NONE
             && ! sem_type->props[i].is_used)

-          complain_at (sem_type->location, Wother,
-                   _("useless %s for type <%s>"),
-                   code_props_type_string (i), sem_type->tag);
+          complain (&sem_type->location, Wother,
+                    _("useless %s for type <%s>"),
+                    code_props_type_string (i), sem_type->tag);

     }
   else
     }
   else

-    complain_at (sem_type->location, Wother,
-                 _("type <%s> is used, but is not associated to any symbol"),
-                 sem_type->tag);
+    complain (&sem_type->location, Wother,
+              _("type <%s> is used, but is not associated to any symbol"),
+              sem_type->tag);

 
   return true;
 }
 
   return true;
 }


@@ -479,10 +486,10 @@ void
 symbol_make_alias (symbol *sym, symbol *str, location loc)
 {
   if (str->alias)
 symbol_make_alias (symbol *sym, symbol *str, location loc)
 {
   if (str->alias)

-    complain_at (loc, Wother,
+    complain (&loc, Wother,

               _("symbol %s used more than once as a literal string"), str->tag);
   else if (sym->alias)
               _("symbol %s used more than once as a literal string"), str->tag);
   else if (sym->alias)

-    complain_at (loc, Wother,
+    complain (&loc, Wother,

               _("symbol %s given more than one literal string"), sym->tag);
   else
     {
               _("symbol %s given more than one literal string"), sym->tag);
   else
     {


@@ -522,11 +529,14 @@ symbol_check_alias_consistency (symbol *this)
     }
 
 
     }
 
 

-  for (int i = 0; i < CODE_PROPS_SIZE; ++i)
-    if (str->props[i].code)
-      symbol_code_props_set (sym, i, &str->props[i]);
-    else if (sym->props[i].code)
-      symbol_code_props_set (str, i, &sym->props[i]);
+  {
+    int i;
+    for (i = 0; i < CODE_PROPS_SIZE; ++i)
+      if (str->props[i].code)
+        symbol_code_props_set (sym, i, &str->props[i]);
+      else if (sym->props[i].code)
+        symbol_code_props_set (str, i, &sym->props[i]);
+  }

 
   if (sym->prec || str->prec)
     {
 
   if (sym->prec || str->prec)
     {


@@ -576,6 +586,7 @@ symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED)
 static void
 user_token_number_redeclaration (int num, symbol *first, symbol *second)
 {
 static void
 user_token_number_redeclaration (int num, symbol *first, symbol *second)
 {

+  unsigned i = 0;

   /* User token numbers are not assigned during the parsing, but in a
      second step, via a traversal of the symbol table sorted on tag.
 
   /* User token numbers are not assigned during the parsing, but in a
      second step, via a traversal of the symbol table sorted on tag.
 


@@ -587,11 +598,13 @@ user_token_number_redeclaration (int num, symbol *first, symbol *second)
       first = second;
       second = tmp;
     }
       first = second;
       second = tmp;
     }

-  complain_at (second->location, complaint,
-               _("user token number %d redeclaration for %s"),
-               num, second->tag);
-  complain_at (first->location, complaint, _("previous declaration for %s"),
-               first->tag);
+  complain_indent (&second->location, complaint, &i,
+                   _("user token number %d redeclaration for %s"),
+                   num, second->tag);
+  i += SUB_INDENT;
+  complain_indent (&first->location, complaint, &i,
+                   _("previous declaration for %s"),
+                   first->tag);

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


@@ -611,10 +624,10 @@ symbol_translation (symbol *this)
           (this->user_token_number,
            symbols[token_translations[this->user_token_number]],
            this);
           (this->user_token_number,
            symbols[token_translations[this->user_token_number]],
            this);

-      
-      token_translations[this->user_token_number] = this->number;
+      else
+        token_translations[this->user_token_number] = this->number;

     }
     }

-  
+

   return true;
 }
 
   return true;
 }
 


@@ -820,6 +833,7 @@ symbols_free (void)
   hash_free (semantic_type_table);
   free (symbols);
   free (symbols_sorted);
   hash_free (semantic_type_table);
   free (symbols);
   free (symbols_sorted);

+  free (semantic_types_sorted);

 }
 
 
 }
 
 


@@ -842,19 +856,19 @@ symbols_cmp_qsort (void const *a, void const *b)
 
 static void
 symbols_do (Hash_processor processor, void *processor_data,
 
 static void
 symbols_do (Hash_processor processor, void *processor_data,

-            struct hash_table *table, symbol **sorted)
+            struct hash_table *table, symbol ***sorted)

 {
   size_t count = hash_get_n_entries (table);
 {
   size_t count = hash_get_n_entries (table);

-  if (!sorted)
+  if (!*sorted)

     {
     {

-      sorted = xnmalloc (count, sizeof *sorted);
-      hash_get_entries (table, (void**)sorted, count);
-      qsort (sorted, count, sizeof *sorted, symbols_cmp_qsort);
+      *sorted = xnmalloc (count, sizeof **sorted);
+      hash_get_entries (table, (void**)*sorted, count);
+      qsort (*sorted, count, sizeof **sorted, symbols_cmp_qsort);

     }
   {
     size_t i;
     for (i = 0; i < count; ++i)
     }
   {
     size_t i;
     for (i = 0; i < count; ++i)

-      processor (sorted[i], processor_data);
+      processor ((*sorted)[i], processor_data);

   }
 }
 
   }
 }
 


@@ -867,9 +881,9 @@ void
 symbols_check_defined (void)
 {
   symbols_do (symbol_check_defined_processor, NULL,
 symbols_check_defined (void)
 {
   symbols_do (symbol_check_defined_processor, NULL,

-              symbol_table, symbols_sorted);
+              symbol_table, &symbols_sorted);

   symbols_do (semantic_type_check_defined_processor, NULL,
   symbols_do (semantic_type_check_defined_processor, NULL,

-              semantic_type_table, semantic_types_sorted);
+              semantic_type_table, &semantic_types_sorted);

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


@@ -924,7 +938,7 @@ symbols_token_translations_init (void)
   for (i = 0; i < max_user_token_number + 1; i++)
     token_translations[i] = undeftoken->number;
   symbols_do (symbol_translation_processor, NULL,
   for (i = 0; i < max_user_token_number + 1; i++)
     token_translations[i] = undeftoken->number;
   symbols_do (symbol_translation_processor, NULL,

-              symbol_table, symbols_sorted);
+              symbol_table, &symbols_sorted);

 }
 
 
 }
 
 


@@ -937,10 +951,10 @@ void
 symbols_pack (void)
 {
   symbols_do (symbol_check_alias_consistency_processor, NULL,
 symbols_pack (void)
 {
   symbols_do (symbol_check_alias_consistency_processor, NULL,

-              symbol_table, symbols_sorted);
+              symbol_table, &symbols_sorted);

 
   symbols = xcalloc (nsyms, sizeof *symbols);
 
   symbols = xcalloc (nsyms, sizeof *symbols);

-  symbols_do (symbol_pack_processor, NULL, symbol_table, symbols_sorted);
+  symbols_do (symbol_pack_processor, NULL, symbol_table, &symbols_sorted);

 
   /* Aliases leave empty slots in symbols, so remove them.  */
   {
 
   /* Aliases leave empty slots in symbols, so remove them.  */
   {


@@ -969,44 +983,195 @@ symbols_pack (void)
   symbols_token_translations_init ();
 
   if (startsymbol->class == unknown_sym)
   symbols_token_translations_init ();
 
   if (startsymbol->class == unknown_sym)

-    complain_at (startsymbol_location, fatal,
-                 _("the start symbol %s is undefined"),
-                 startsymbol->tag);
+    complain (&startsymbol_location, fatal,
+              _("the start symbol %s is undefined"),
+              startsymbol->tag);

   else if (startsymbol->class == token_sym)
   else if (startsymbol->class == token_sym)

-    complain_at (startsymbol_location, fatal,
-                 _("the start symbol %s is a token"),
-                 startsymbol->tag);
+    complain (&startsymbol_location, fatal,
+              _("the start symbol %s is a token"),
+              startsymbol->tag);

 }
 
 }
 

+/*---------------------------------.
+| Initialize relation graph nodes. |
+`---------------------------------*/

 
 

-/*--------------------------------------------------.
-| Set default tagged/tagless %destructor/%printer.  |
-`--------------------------------------------------*/
+static void
+init_prec_nodes (void)
+{
+  int i;
+  prec_nodes = xcalloc (nsyms, sizeof *prec_nodes);
+  for (i = 0; i < nsyms; ++i)
+    {
+      prec_nodes[i] = xmalloc (sizeof *prec_nodes[i]);
+      symgraph *s = prec_nodes[i];
+      s->id = i;
+      s->succ = 0;
+      s->pred = 0;
+    }
+}
+
+/*----------------.
+| Create a link.  |
+`----------------*/
+
+static symgraphlink *
+symgraphlink_new (graphid id, symgraphlink *next)
+{
+  symgraphlink *l = xmalloc (sizeof *l);
+  l->id = id;
+  l->next = next;
+  return l;
+}
+
+
+/*------------------------------------------------------------------.
+| Register the second symbol of the precedence relation, and return |
+| whether this relation is new.  Use only in register_precedence.   |
+`------------------------------------------------------------------*/
+
+static bool
+register_precedence_second_symbol (symgraphlink **first, graphid sym)
+{
+  if (!*first || sym < (*first)->id)
+    *first = symgraphlink_new (sym, *first);
+  else
+    {
+      symgraphlink *slist = *first;
+
+      while (slist->next && slist->next->id <= sym)
+        slist = slist->next;
+
+      if (slist->id == sym)
+        /* Relation already present. */
+        return false;
+
+      slist->next = symgraphlink_new (sym, slist->next);
+    }
+  return true;
+}
+
+/*------------------------------------------------------------------.
+| Register a new relation between symbols as used. The first symbol |
+| has a greater precedence than the second one.                     |
+`------------------------------------------------------------------*/

 
 void
 
 void

-default_tagged_code_props_set (code_props_type kind, code_props const *code)
+register_precedence (graphid first, graphid snd)
+{
+  if (!prec_nodes)
+    init_prec_nodes ();
+  register_precedence_second_symbol (&(prec_nodes[first]->succ), snd);
+  register_precedence_second_symbol (&(prec_nodes[snd]->pred), first);
+}
+
+
+/*---------------------------------------.
+| Deep clear a linked / adjacency list). |
+`---------------------------------------*/
+
+static void
+linkedlist_free (symgraphlink *node)

 {
 {

-  if (default_tagged_code_props[kind].code)
+  if (node)

     {
     {

-      complain_at (code->location, complaint,
-                   _("redeclaration for default tagged %s"),
-                   code_props_type_string (kind));
-      complain_at (default_tagged_code_props[kind].location, complaint,
-                   _("previous declaration"));
+      while (node->next)
+        {
+          symgraphlink *tmp = node->next;
+          free (node);
+          node = tmp;
+        }
+      free (node);

     }
     }

-  default_tagged_code_props[kind] = *code;

 }
 
 }
 

+/*----------------------------------------------.
+| Clear and destroy association tracking table. |
+`----------------------------------------------*/
+
+static void
+assoc_free (void)
+{
+  int i;
+  for (i = 0; i < nsyms; ++i)
+    {
+      linkedlist_free (prec_nodes[i]->pred);
+      linkedlist_free (prec_nodes[i]->succ);
+      free (prec_nodes[i]);
+    }
+  free (prec_nodes);
+}
+
+/*---------------------------------------.
+| Initialize association tracking table. |
+`---------------------------------------*/
+
+static void
+init_assoc (void)
+{
+  graphid i;
+  used_assoc = xcalloc (nsyms, sizeof *used_assoc);
+  for (i = 0; i < nsyms; ++i)
+    used_assoc[i] = false;
+}
+
+/*------------------------------------------------------------------.
+| Test if the associativity for the symbols is defined and useless. |
+`------------------------------------------------------------------*/
+
+static inline bool
+is_assoc_useless (symbol *s)
+{
+  return s
+      && s->assoc != undef_assoc
+      && s->assoc != precedence_assoc
+      && !used_assoc[s->number];
+}
+
+/*-------------------------------.
+| Register a used associativity. |
+`-------------------------------*/
+
+void
+register_assoc (graphid i, graphid j)
+{
+  if (!used_assoc)
+    init_assoc ();
+  used_assoc[i] = true;
+  used_assoc[j] = true;
+}
+
+/*--------------------------------------------------.
+| Print a warning for unused precedence relations.  |
+`--------------------------------------------------*/
+

 void
 void

-default_tagless_code_props_set (code_props_type kind, code_props const *code)
+print_precedence_warnings (void)

 {
 {

-  if (default_tagless_code_props[kind].code)
+  int i;
+  if (!prec_nodes)
+    init_prec_nodes ();
+  if (!used_assoc)
+    init_assoc ();
+  for (i = 0; i < nsyms; ++i)

     {
     {

-      complain_at (code->location, complaint,
-                   _("redeclaration for default tagless %s"),
-                   code_props_type_string (kind));
-      complain_at (default_tagless_code_props[kind].location, complaint,
-                   _("previous declaration"));
+      symbol *s = symbols[i];
+      if (s
+          && s->prec != 0
+          && !prec_nodes[i]->pred
+          && !prec_nodes[i]->succ)
+        {
+          if (is_assoc_useless (s))
+            complain (&s->prec_location, Wprecedence,
+                      _("useless precedence and associativity for %s"), s->tag);
+          else if (s->assoc == precedence_assoc)
+            complain (&s->prec_location, Wprecedence,
+                      _("useless precedence for %s"), s->tag);
+        }
+      else if (is_assoc_useless (s))
+        complain (&s->prec_location, Wprecedence,
+                  _("useless associativity for %s, use %%precedence"), s->tag);

     }
     }

-  default_tagless_code_props[kind] = *code;
+  free (used_assoc);
+  assoc_free ();

 }
 }