warnings: introduce -Wprecedence

[bison.git] / src / symtab.c

diff --git a/src/symtab.c b/src/symtab.c
index f4f35290837bd4f16fe02f1c133174503a0c9827..d3ad2fbbdfc4babffcde095f12ba5e78459cc894 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.


@@ -33,6 +33,7 @@
 `-------------------------------------------------------------------*/
 
 static symbol **symbols_sorted = NULL;
 `-------------------------------------------------------------------*/
 
 static symbol **symbols_sorted = NULL;

+static symbol **semantic_types_sorted = NULL;

 
 /*------------------------.
 | Distinguished symbols.  |
 
 /*------------------------.
 | Distinguished symbols.  |


@@ -45,14 +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 symgraph **prec_nodes;

 
 

-static code_props default_tagged_destructor = CODE_PROPS_NONE_INIT;
-static code_props default_tagless_destructor = CODE_PROPS_NONE_INIT;
-static code_props default_tagged_printer = CODE_PROPS_NONE_INIT;
-static code_props default_tagless_printer = CODE_PROPS_NONE_INIT;
+/*-----------------------------------.
+| Store which associativity is used. |
+`-----------------------------------*/
+
+bool *used_assoc = NULL;

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


@@ -62,21 +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, '-'))

-    yacc_at (loc, _("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;

-  code_props_none_init (&res->destructor);
-  code_props_none_init (&res->printer);
+  {
+    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;


@@ -88,25 +94,43 @@ symbol_new (uniqstr tag, location loc)
   res->status = undeclared;
 
   if (nsyms == SYMBOL_NUMBER_MAXIMUM)
   res->status = undeclared;
 
   if (nsyms == SYMBOL_NUMBER_MAXIMUM)

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

   nsyms++;
   return res;
 }
 
   nsyms++;
   return res;
 }
 

+char const *
+code_props_type_string (code_props_type kind)
+{
+  switch (kind)
+    {
+    case destructor:
+      return "%destructor";
+    case printer:
+      return "%printer";
+    }
+  assert (0);
+}
+

 /*----------------------------------------.
 | Create a new semantic type, named TAG.  |
 `----------------------------------------*/
 
 static semantic_type *
 /*----------------------------------------.
 | Create a new semantic type, named TAG.  |
 `----------------------------------------*/
 
 static semantic_type *

-semantic_type_new (uniqstr tag)
+semantic_type_new (uniqstr tag, const location *loc)

 {
   semantic_type *res = xmalloc (sizeof *res);
 
   uniqstr_assert (tag);
   res->tag = tag;
 {
   semantic_type *res = xmalloc (sizeof *res);
 
   uniqstr_assert (tag);
   res->tag = tag;

-  code_props_none_init (&res->destructor);
-  code_props_none_init (&res->printer);
+  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;
 }


@@ -120,12 +144,12 @@ semantic_type_new (uniqstr tag)
   if (s->Attr)                                          \
     fprintf (f, " %s { %s }", #Attr, s->Attr)
 
   if (s->Attr)                                          \
     fprintf (f, " %s { %s }", #Attr, s->Attr)
 

-#define SYMBOL_CODE_PRINT(Attr)                         \
-  if (s->Attr.code)                                     \
-    fprintf (f, " %s { %s }", #Attr, s->Attr.code)
+#define SYMBOL_CODE_PRINT(Attr)                                         \
+  if (s->props[Attr].code)                                              \
+    fprintf (f, " %s { %s }", #Attr, s->props[Attr].code)

 
 void
 
 void

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

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


@@ -185,16 +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, _("%s redeclaration for %s"), what, s->tag);
-  complain_at (first, _("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, _("%s redeclaration for <%s>"), what, s->tag);
-  complain_at (first, _("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"));

 }
 
 
 }
 
 


@@ -217,115 +249,66 @@ symbol_type_set (symbol *sym, uniqstr type_name, location loc)
     }
 }
 
     }
 }
 

-/*-----------------------------------------.
-| Set the DESTRUCTOR associated with SYM.  |
-`-----------------------------------------*/
+/*--------------------------------------------------------.
+| Set the DESTRUCTOR or PRINTER associated with the SYM.  |
+`--------------------------------------------------------*/

 
 void
 
 void

-symbol_destructor_set (symbol *sym, code_props const *destructor)
+symbol_code_props_set (symbol *sym, code_props_type kind,
+                       code_props const *code)

 {
 {

-  if (sym->destructor.code)
-    symbol_redeclaration (sym, "%destructor", sym->destructor.location,
-                          destructor->location);
-  sym->destructor = *destructor;
+  if (sym->props[kind].code)
+    symbol_redeclaration (sym, code_props_type_string (kind),
+                          sym->props[kind].location,
+                          code->location);
+  sym->props[kind] = *code;

 }
 
 }
 

-/*------------------------------------------.
-| Set the DESTRUCTOR associated with TYPE.  |
-`------------------------------------------*/
+/*-----------------------------------------------------.
+| Set the DESTRUCTOR or PRINTER associated with TYPE.  |
+`-----------------------------------------------------*/

 
 void
 
 void

-semantic_type_destructor_set (semantic_type *type,
-                              code_props const *destructor)
+semantic_type_code_props_set (semantic_type *type,
+                              code_props_type kind,
+                              code_props const *code)

 {
 {

-  if (type->destructor.code)
-    semantic_type_redeclaration (type, "%destructor",
-                                 type->destructor.location,
-                                 destructor->location);
-  type->destructor = *destructor;
+  if (type->props[kind].code)
+    semantic_type_redeclaration (type, code_props_type_string (kind),
+                                 type->props[kind].location,
+                                 code->location);
+  type->props[kind] = *code;

 }
 
 }
 

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

 
 

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

 {
 {

-  /* Per-symbol %destructor.  */
-  if (sym->destructor.code)
-    return &sym->destructor;
+  /* Per-symbol code props.  */
+  if (sym->props[kind].code)
+    return &sym->props[kind];

 
 

-  /* Per-type %destructor.  */
+  /* Per-type code props.  */

   if (sym->type_name)
     {
   if (sym->type_name)
     {

-      code_props const *destructor =
-        &semantic_type_get (sym->type_name)->destructor;
-      if (destructor->code)
-        return destructor;
+      code_props *code =
+        &semantic_type_get (sym->type_name, NULL)->props[kind];
+      if (code->code)
+        return code;

     }
 
     }
 

-  /* Apply default %destructor's only to user-defined symbols.  */
-  if (sym->tag[0] == '$' || sym == errtoken)
-    return &code_props_none;
-
-  if (sym->type_name)
-    return &default_tagged_destructor;
-  return &default_tagless_destructor;
-}
-
-/*--------------------------------------.
-| Set the PRINTER associated with SYM.  |
-`--------------------------------------*/
-
-void
-symbol_printer_set (symbol *sym, code_props const *printer)
-{
-  if (sym->printer.code)
-    symbol_redeclaration (sym, "%printer",
-                          sym->printer.location, printer->location);
-  sym->printer = *printer;
-}
-
-/*---------------------------------------.
-| Set the PRINTER associated with TYPE.  |
-`---------------------------------------*/
-
-void
-semantic_type_printer_set (semantic_type *type, code_props const *printer)
-{
-  if (type->printer.code)
-    semantic_type_redeclaration (type, "%printer",
-                                 type->printer.location, printer->location);
-  type->printer = *printer;
-}
-
-/*------------------------------------.
-| Get the computed %printer for SYM.  |
-`------------------------------------*/
-
-code_props const *
-symbol_printer_get (symbol const *sym)
-{
-  /* Per-symbol %printer.  */
-  if (sym->printer.code)
-    return &sym->printer;
-
-  /* Per-type %printer.  */
-  if (sym->type_name)
+  /* Apply default code props's only to user-defined symbols.  */
+  if (sym->tag[0] != '$' && sym != errtoken)

     {
     {

-      code_props const *printer = &semantic_type_get (sym->type_name)->printer;
-      if (printer->code)
-        return printer;
+      code_props *code =
+        &semantic_type_get (sym->type_name ? "*" : "", NULL)->props[kind];
+      if (code->code)
+        return code;

     }
     }

-
-  /* Apply the default %printer only to user-defined symbols.  */
-  if (sym->tag[0] == '$' || sym == errtoken)
-    return &code_props_none;
-
-  if (sym->type_name)
-    return &default_tagged_printer;
-  return &default_tagless_printer;
+  return &code_props_none;

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


@@ -361,8 +344,8 @@ 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, _("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;
     }
 


@@ -376,7 +359,7 @@ 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)

-        warn_at (loc, _("symbol %s redeclared"), sym->tag);
+        complain (&loc, Wother, _("symbol %s redeclared"), sym->tag);

       sym->status = declared;
     }
 }
       sym->status = declared;
     }
 }


@@ -397,7 +380,8 @@ 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, _("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? */


@@ -423,30 +407,55 @@ symbol_check_defined (symbol *sym)
 {
   if (sym->class == unknown_sym)
     {
 {
   if (sym->class == unknown_sym)
     {

-      switch (sym->status)
-        {
-        case used:
-          warn_at (sym->location,
-                   _("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,
-                       _("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++;
     }
 

+  {
+    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. */
+  if (sym->type_name)
+    {
+      semantic_type *sem_type = semantic_type_get (sym->type_name, NULL);
+      if (sem_type)
+        sem_type->status = declared;
+    }
+
+  return true;
+}
+
+static inline bool
+semantic_type_check_defined (semantic_type *sem_type)
+{
+  /* <*> and <> do not have to be "declared".  */
+  if (sem_type->status == declared
+      || !*sem_type->tag
+      || STREQ(sem_type->tag, "*"))
+    {
+      int i;
+      for (i = 0; i < 2; ++i)
+        if (sem_type->props[i].kind != CODE_PROPS_NONE
+            && ! sem_type->props[i].is_used)
+          complain (&sem_type->location, Wother,
+                    _("useless %s for type <%s>"),
+                    code_props_type_string (i), sem_type->tag);
+    }
+  else
+    complain (&sem_type->location, Wother,
+              _("type <%s> is used, but is not associated to any symbol"),
+              sem_type->tag);
+

   return true;
 }
 
   return true;
 }
 


@@ -456,16 +465,23 @@ symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
   return symbol_check_defined (sym);
 }
 
   return symbol_check_defined (sym);
 }
 

+static bool
+semantic_type_check_defined_processor (void *sem_type,
+                                       void *null ATTRIBUTE_UNUSED)
+{
+  return semantic_type_check_defined (sem_type);
+}
+

 
 void
 symbol_make_alias (symbol *sym, symbol *str, location loc)
 {
   if (str->alias)
 
 void
 symbol_make_alias (symbol *sym, symbol *str, location loc)
 {
   if (str->alias)

-    warn_at (loc, _("symbol %s used more than once as a literal string"),
-             str->tag);
+    complain (&loc, Wother,
+              _("symbol %s used more than once as a literal string"), str->tag);

   else if (sym->alias)
   else if (sym->alias)

-    warn_at (loc, _("symbol %s given more than one literal string"),
-             sym->tag);
+    complain (&loc, Wother,
+              _("symbol %s given more than one literal string"), sym->tag);

   else
     {
       str->class = token_sym;
   else
     {
       str->class = token_sym;


@@ -504,21 +520,14 @@ symbol_check_alias_consistency (symbol *this)
     }
 
 
     }
 
 

-  if (str->destructor.code || sym->destructor.code)
-    {
-      if (str->destructor.code)
-        symbol_destructor_set (sym, &str->destructor);
-      else
-        symbol_destructor_set (str, &sym->destructor);
-    }
-
-  if (str->printer.code || sym->printer.code)
-    {
-      if (str->printer.code)
-        symbol_printer_set (sym, &str->printer);
-      else
-        symbol_printer_set (str, &sym->printer);
-    }
+  {
+    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)
     {


@@ -568,6 +577,7 @@ 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.
 


@@ -579,11 +589,13 @@ user_token_number_redeclaration (int num, symbol *first, symbol *second)
       first = second;
       second = tmp;
     }
       first = second;
       second = tmp;
     }

-  complain_at (second->location,
-               _("user token number %d redeclaration for %s"),
-               num, second->tag);
-  complain_at (first->location, _("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);

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


@@ -731,7 +743,7 @@ symbol_from_uniqstr (const uniqstr key, location loc)
 `-----------------------------------------------------------------------*/
 
 semantic_type *
 `-----------------------------------------------------------------------*/
 
 semantic_type *

-semantic_type_from_uniqstr (const uniqstr key)
+semantic_type_from_uniqstr (const uniqstr key, const location *loc)

 {
   semantic_type probe;
   semantic_type *entry;
 {
   semantic_type probe;
   semantic_type *entry;


@@ -742,7 +754,7 @@ semantic_type_from_uniqstr (const uniqstr key)
   if (!entry)
     {
       /* First insertion in the hash. */
   if (!entry)
     {
       /* First insertion in the hash. */

-      entry = semantic_type_new (key);
+      entry = semantic_type_new (key, loc);

       if (!hash_insert (semantic_type_table, entry))
         xalloc_die ();
     }
       if (!hash_insert (semantic_type_table, entry))
         xalloc_die ();
     }


@@ -768,9 +780,9 @@ symbol_get (const char *key, location loc)
 `-----------------------------------------------------------------------*/
 
 semantic_type *
 `-----------------------------------------------------------------------*/
 
 semantic_type *

-semantic_type_get (const char *key)
+semantic_type_get (const char *key, const location *loc)

 {
 {

-  return semantic_type_from_uniqstr (uniqstr_new (key));
+  return semantic_type_from_uniqstr (uniqstr_new (key), loc);

 }
 
 
 }
 
 


@@ -812,6 +824,7 @@ 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);

 }
 
 
 }
 
 


@@ -834,19 +847,19 @@ 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);

   }
 }
 
   }
 }
 


@@ -859,7 +872,9 @@ 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,
+              semantic_type_table, &semantic_types_sorted);

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


@@ -914,7 +929,7 @@ 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);

 }
 
 
 }
 
 


@@ -927,10 +942,10 @@ 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.  */
   {


@@ -959,68 +974,157 @@ symbols_pack (void)
   symbols_token_translations_init ();
 
   if (startsymbol->class == unknown_sym)
   symbols_token_translations_init ();
 
   if (startsymbol->class == unknown_sym)

-    fatal_at (startsymbol_location,
+    complain (&startsymbol_location, fatal,

               _("the start symbol %s is undefined"),
               startsymbol->tag);
   else if (startsymbol->class == token_sym)
               _("the start symbol %s is undefined"),
               startsymbol->tag);
   else if (startsymbol->class == token_sym)

-    fatal_at (startsymbol_location,
+    complain (&startsymbol_location, fatal,

               _("the start symbol %s is a token"),
               startsymbol->tag);
 }
 
               _("the start symbol %s is a token"),
               startsymbol->tag);
 }
 

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

 
 

-/*--------------------------------------------------.
-| Set default tagged/tagless %destructor/%printer.  |
-`--------------------------------------------------*/
-
-void
-default_tagged_destructor_set (code_props const *destructor)
+static void
+init_prec_nodes (void)

 {
 {

-  if (default_tagged_destructor.code)
+  int i;
+  prec_nodes = xcalloc (nsyms, sizeof *prec_nodes);
+  for (i = 0; i < nsyms; ++i)

     {
     {

-      complain_at (destructor->location,
-                   _("redeclaration for default tagged %%destructor"));
-      complain_at (default_tagged_destructor.location,
-                   _("previous declaration"));
+      prec_nodes[i] = xmalloc (sizeof *prec_nodes[i]);
+      symgraph *s = prec_nodes[i];
+      s->id = i;
+      s->succ = 0;
+      s->pred = 0;

     }
     }

-  default_tagged_destructor = *destructor;

 }
 
 }
 

-void
-default_tagless_destructor_set (code_props const *destructor)
+/*----------------.
+| Create a link.  |
+`----------------*/
+
+static symgraphlink *
+symgraphlink_new (graphid id, symgraphlink *next)

 {
 {

-  if (default_tagless_destructor.code)
+  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

     {
     {

-      complain_at (destructor->location,
-                   _("redeclaration for default tagless %%destructor"));
-      complain_at (default_tagless_destructor.location,
-                   _("previous declaration"));
+      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);

     }
     }

-  default_tagless_destructor = *destructor;
+  return true;
+}
+
+/*------------------------------------------------------------------.
+| Register a new relation between symbols as used. The first symbol |
+| has a greater precedence than the second one.                     |
+`------------------------------------------------------------------*/
+
+void
+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);
+}
+
+
+/*---------------------------------------.
+| 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
 void

-default_tagged_printer_set (code_props const *printer)
+register_assoc (graphid i, graphid j)

 {
 {

-  if (default_tagged_printer.code)
-    {
-      complain_at (printer->location,
-                   _("redeclaration for default tagged %%printer"));
-      complain_at (default_tagged_printer.location,
-                   _("previous declaration"));
-    }
-  default_tagged_printer = *printer;
+  if (!used_assoc)
+    init_assoc ();
+  used_assoc[i] = true;
+  used_assoc[j] = true;

 }
 
 }
 

+/*--------------------------------------------------.
+| Print a warning for unused precedence relations.  |
+`--------------------------------------------------*/
+

 void
 void

-default_tagless_printer_set (code_props const *printer)
+print_precedence_warnings (void)

 {
 {

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

     {
     {

-      complain_at (printer->location,
-                   _("redeclaration for default tagless %%printer"));
-      complain_at (default_tagless_printer.location,
-                   _("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->location, Wprecedence,
+                      _("useless precedence and associativity for %s"), s->tag);
+          else if (s->assoc == precedence_assoc)
+            complain (&s->location, Wprecedence,
+                      _("useless precedence for %s"), s->tag);
+        }
+      else if (is_assoc_useless (s))
+        complain (&s->location, Wprecedence,
+                  _("useless associativity for %s, use %%precedence"), s->tag);

     }
     }

-  default_tagless_printer = *printer;

 }
 }