Finish implementation of per-type %destructor/%printer. Discussed

starting at
<http://lists.gnu.org/archive/html/bison-patches/2006-02/msg00064.html>
and
<http://lists.gnu.org/archive/html/bison-patches/2006-06/msg00091.html>.
* NEWS (2.3+): Add a description of this feature to the default
%destructor/%printer description.
* doc/bison.texinfo (Freeing Discarded Symbols): Likewise.
* src/symlist.c (symbol_list_destructor_set, symbol_list_printer_set):
Invoke semantic_type_destructor_set or semantic_type_printer_set when a
list node contains a semantic type.
* src/symtab.c, src/symtab.h: Extend with a table that associates
semantic types with their %destructor's and %printer's.
(semantic_type_from_uniqstr, semantic_type_get,
semantic_type_destructor_set, semantic_type_printer_set): New functions
composing the public interface of that table.
(symbol_destructor_get, symbol_destructor_location_get,
symbol_printer_get, symbol_printer_location_get):  If there's no
per-symbol %destructor/%printer, look up the per-type before trying
the default.
* tests/actions.at (Per-type %printer and %destructor): New test case.
* tests/input.at (Default %printer and %destructor redeclared):
Extend to check that multiple occurrences of %symbol-default in a
single %destructor/%printer declaration is an error.
(Per-type %printer and %destructor redeclared, Unused values with
per-type %destructor): New test cases.

ChangeLog

@@ -1,3 +1,32 @@
+2006-09-04  Joel E. Denny  <jdenny@ces.clemson.edu>
+
+	Finish implementation of per-type %destructor/%printer.  Discussed
+	starting at
+	<http://lists.gnu.org/archive/html/bison-patches/2006-02/msg00064.html>
+	and
+	<http://lists.gnu.org/archive/html/bison-patches/2006-06/msg00091.html>.
+	* NEWS (2.3+): Add a description of this feature to the default
+	%destructor/%printer description.
+	* doc/bison.texinfo (Freeing Discarded Symbols): Likewise.
+	* src/symlist.c (symbol_list_destructor_set, symbol_list_printer_set):
+	Invoke semantic_type_destructor_set or semantic_type_printer_set when a
+	list node contains a semantic type.
+	* src/symtab.c, src/symtab.h: Extend with a table that associates
+	semantic types with their %destructor's and %printer's.
+	(semantic_type_from_uniqstr, semantic_type_get,
+	semantic_type_destructor_set, semantic_type_printer_set): New functions
+	composing the public interface of that table.
+	(symbol_destructor_get, symbol_destructor_location_get,
+	symbol_printer_get, symbol_printer_location_get):  If there's no
+	per-symbol %destructor/%printer, look up the per-type before trying
+	the default.
+	* tests/actions.at (Per-type %printer and %destructor): New test case.
+	* tests/input.at (Default %printer and %destructor redeclared):
+	Extend to check that multiple occurrences of %symbol-default in a
+	single %destructor/%printer declaration is an error.
+	(Per-type %printer and %destructor redeclared, Unused values with
+	per-type %destructor): New test cases.
+
 2006-09-04  Joel E. Denny  <jdenny@ces.clemson.edu>
 
 	Require default %destructor/%printer to be declared using

NEWS

@@ -12,22 +12,27 @@ Changes in version 2.3+:
 * Locations columns and lines start at 1.
   In accordance with the GNU Coding Standards and Emacs.
 
-* You may now declare a default %destructor and %printer:
+* You may now declare per-type and default %destructor's and %printer's:
 
   For example:
 
-     %union { char *string; }
+    %union { char *string; }
-     %token <string> STRING1
+    %token <string> STRING1
-     %token <string> STRING2
+    %token <string> STRING2
-     %type  <string> string1
+    %type  <string> string1
-     %type  <string> string2
+    %type  <string> string2
-     %destructor { free ($$); } %symbol-default
+    %union { char character; }
-     %destructor { free ($$); printf ("%d", @$.first_line); } STRING1 string1
+    %token <character> CHR
+    %type  <character> chr
+    %destructor { free ($$); } %symbol-default
+    %destructor { free ($$); printf ("%d", @$.first_line); } STRING1 string1
+    %destructor { } <character>
 
-  guarantees that, when the parser discards any user-defined symbol, it passes
+  guarantees that, when the parser discards any user-defined symbol that has a
-  its semantic value to `free'.  However, when the parser discards a `STRING1'
+  semantic type tag other than `<character>', it passes its semantic value to
-  or a `string1', it also prints its line number to `stdout'.  It performs only
+  `free'.  However, when the parser discards a `STRING1' or a `string1', it
-  the second `%destructor' in this case, so it invokes `free' only once.
+  also prints its line number to `stdout'.  It performs only the second
+  `%destructor' in this case, so it invokes `free' only once.
 
 * Except for LALR(1) parsers in C with POSIX Yacc emulation enabled (with `-y',
   `--yacc', or `%yacc'), Bison no longer generates #define statements for

doc/bison.texinfo

@@ -4011,19 +4011,24 @@ Within @var{code}, @code{$$} designates the semantic value associated
 with the discarded symbol, and @code{@@$} designates its location.
 The additional parser parameters are also available (@pxref{Parser Function, ,
 The Parser Function @code{yyparse}}).
+
+When a symbol is listed among @var{symbols}, its @code{%destructor} is called a
+per-symbol @code{%destructor}.
+You may also define a per-type @code{%destructor} by listing a semantic type
+among @var{symbols}.
+In that case, the parser will invoke this @var{code} whenever it discards any
+grammar symbol that has that semantic type unless that symbol has its own
+per-symbol @code{%destructor}.
+
+Finally, you may define a default @code{%destructor} by placing
+@code{%symbol-default} in the @var{symbols} list of exactly one
+@code{%destructor} declaration in your grammar file.
+In that case, the parser will invoke the associated @var{code} whenever it
+discards any user-defined grammar symbol for which there is no per-type or
+per-symbol @code{%destructor}.
 @end deffn
 
-@deffn {Directive} %destructor @{ @var{code} @} %symbol-default
+@noindent
-@cindex default %destructor
-@findex %symbol-default
-Invoke the braced @var{code} whenever the parser discards any user-defined
-grammar symbol for which the user has not specifically declared any
-@code{%destructor}.
-This is known as the default @code{%destructor}.
-As in the previous form, @code{$$}, @code{@@$}, and the additional parser
-parameters are available.
-@end deffn
-
 For instance:
 
 @smallexample
@@ -4032,13 +4037,18 @@ For instance:
 %token <string> STRING2
 %type  <string> string1
 %type  <string> string2
+%union @{ char character; @}
+%token <character> CHR
+%type  <character> chr
 %destructor @{ free ($$); @} %symbol-default
 %destructor @{ free ($$); printf ("%d", @@$.first_line); @} STRING1 string1
+%destructor @{ @} <character>
 @end smallexample
 
 @noindent
-guarantees that, when the parser discards any user-defined symbol, it passes
+guarantees that, when the parser discards any user-defined symbol that has a
-its semantic value to @code{free}.
+semantic type tag other than @code{<character>}, it passes its semantic value
+to @code{free}.
 However, when the parser discards a @code{STRING1} or a @code{string1}, it also
 prints its line number to @code{stdout}.
 It performs only the second @code{%destructor} in this case, so it invokes

src/symlist.c

@@ -212,7 +212,8 @@ symbol_list_destructor_set (symbol_list *node, const char *destructor,
         symbol_destructor_set (node->content.sym, destructor, loc);
         break;
       case SYMLIST_TYPE:
-        /* FIXME: */
+        semantic_type_destructor_set (
+          semantic_type_get (node->content.type_name), destructor, loc);
         break;
       case SYMLIST_DEFAULT:
         default_destructor_set (destructor, loc);
@@ -229,7 +230,8 @@ symbol_list_printer_set (symbol_list *node, const char *printer, location loc)
         symbol_printer_set (node->content.sym, printer, loc);
         break;
       case SYMLIST_TYPE:
-        /* FIXME: */
+        semantic_type_printer_set (
+          semantic_type_get (node->content.type_name), printer, loc);
         break;
       case SYMLIST_DEFAULT:
         default_printer_set (printer, loc);

src/symtab.c

@@ -83,6 +83,23 @@ symbol_new (uniqstr tag, location loc)
   return res;
 }
 
+/*----------------------------------------.
+| Create a new semantic type, named TAG.  |
+`----------------------------------------*/
+
+static semantic_type *
+semantic_type_new (uniqstr tag)
+{
+  semantic_type *res = xmalloc (sizeof *res);
+
+  uniqstr_assert (tag);
+  res->tag = tag;
+  res->destructor = NULL;
+  res->printer = NULL;
+
+  return res;
+}
+
 
 /*-----------------.
 | Print a symbol.  |
@@ -114,12 +131,21 @@ symbol_print (symbol *s, FILE *f)
 `------------------------------------------------------------------*/
 
 static void
-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"));
 }
 
+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"));
+}
+
 
 /*-----------------------------------------------------------------.
 | Set the TYPE_NAME associated with SYM.  Does nothing if passed 0 |
@@ -132,7 +158,7 @@ symbol_type_set (symbol *sym, uniqstr type_name, location loc)
   if (type_name)
     {
       if (sym->type_name)
-	redeclaration (sym, "%type", sym->type_location, loc);
+	symbol_redeclaration (sym, "%type", sym->type_location, loc);
       uniqstr_assert (type_name);
       sym->type_name = type_name;
       sym->type_location = loc;
@@ -150,12 +176,31 @@ symbol_destructor_set (symbol *sym, const char *destructor, location loc)
   if (destructor)
     {
       if (sym->destructor)
-	redeclaration (sym, "%destructor", sym->destructor_location, loc);
+	symbol_redeclaration (sym, "%destructor", sym->destructor_location,
+                              loc);
       sym->destructor = destructor;
       sym->destructor_location = loc;
     }
 }
 
+/*-------------------------------------------------------------------.
+| Set the DESTRUCTOR associated with TYPE.  Do nothing if passed 0.  |
+`-------------------------------------------------------------------*/
+
+void
+semantic_type_destructor_set (semantic_type *type, const char *destructor,
+                              location loc)
+{
+  if (destructor)
+    {
+      if (type->destructor)
+	semantic_type_redeclaration (type, "%destructor",
+                                     type->destructor_location, loc);
+      type->destructor = destructor;
+      type->destructor_location = loc;
+    }
+}
+
 /*---------------------------------------.
 | Get the computed %destructor for SYM.  |
 `---------------------------------------*/
@@ -167,6 +212,14 @@ symbol_destructor_get (symbol *sym)
   if (sym->destructor != NULL)
     return sym->destructor;
 
+  /* Per-type %destructor.  */
+  if (sym->type_name)
+    {
+      semantic_type *type = semantic_type_get (sym->type_name);
+      if (type->destructor)
+        return type->destructor;
+    }
+
   /* Apply the default %destructor only to user-defined symbols.  */
   if (sym->tag[0] == '$' || sym == errtoken)
     return NULL;
@@ -182,6 +235,12 @@ symbol_destructor_location_get (symbol *sym)
 {
   if (sym->destructor != NULL)
     return sym->destructor_location;
+  if (sym->type_name)
+    {
+      semantic_type *type = semantic_type_get (sym->type_name);
+      if (type->destructor)
+        return type->destructor_location;
+    }
   return default_destructor_location;
 }
 
@@ -195,12 +254,30 @@ symbol_printer_set (symbol *sym, const char *printer, location loc)
   if (printer)
     {
       if (sym->printer)
-	redeclaration (sym, "%printer", sym->printer_location, loc);
+	symbol_redeclaration (sym, "%printer", sym->printer_location, loc);
       sym->printer = printer;
       sym->printer_location = loc;
     }
 }
 
+/*----------------------------------------------------------------.
+| Set the PRINTER associated with TYPE.  Do nothing if passed 0.  |
+`----------------------------------------------------------------*/
+
+void
+semantic_type_printer_set (semantic_type *type, const char *printer,
+                           location loc)
+{
+  if (printer)
+    {
+      if (type->printer)
+	semantic_type_redeclaration (type, "%printer", type->printer_location,
+                                     loc);
+      type->printer = printer;
+      type->printer_location = loc;
+    }
+}
+
 /*------------------------------------.
 | Get the computed %printer for SYM.  |
 `------------------------------------*/
@@ -212,6 +289,14 @@ symbol_printer_get (symbol *sym)
   if (sym->printer != NULL)
     return sym->printer;
 
+  /* Per-type %printer.  */
+  if (sym->type_name)
+    {
+      semantic_type *type = semantic_type_get (sym->type_name);
+      if (type->printer)
+        return type->printer;
+    }
+
   /* Apply the default %printer only to user-defined symbols.  */
   if (sym->tag[0] == '$' || sym == errtoken)
     return NULL;
@@ -227,6 +312,12 @@ symbol_printer_location_get (symbol *sym)
 {
   if (sym->printer != NULL)
     return sym->printer_location;
+  if (sym->type_name)
+    {
+      semantic_type *type = semantic_type_get (sym->type_name);
+      if (type->printer)
+        return type->printer_location;
+    }
   return default_printer_location;
 }
 
@@ -242,7 +333,8 @@ symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
   if (a != undef_assoc)
     {
       if (sym->prec != 0)
-	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;
@@ -509,14 +601,15 @@ symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
 }
 
 
-/*----------------------.
+/*---------------------------------------.
-| A symbol hash table.  |
+| Symbol and semantic type hash tables.  |
-`----------------------*/
+`---------------------------------------*/
 
-/* Initial capacity of symbols hash table.  */
+/* Initial capacity of symbol and semantic type hash table.  */
 #define HT_INITIAL_CAPACITY 257
 
 static struct hash_table *symbol_table = NULL;
+static struct hash_table *semantic_type_table = NULL;
 
 static inline bool
 hash_compare_symbol (const symbol *m1, const symbol *m2)
@@ -525,12 +618,25 @@ hash_compare_symbol (const symbol *m1, const symbol *m2)
   return UNIQSTR_EQ (m1->tag, m2->tag);
 }
 
+static inline bool
+hash_compare_semantic_type (const semantic_type *m1, const semantic_type *m2)
+{
+  /* Since names are unique, we can compare the pointers themselves.  */
+  return UNIQSTR_EQ (m1->tag, m2->tag);
+}
+
 static bool
 hash_symbol_comparator (void const *m1, void const *m2)
 {
   return hash_compare_symbol (m1, m2);
 }
 
+static bool
+hash_semantic_type_comparator (void const *m1, void const *m2)
+{
+  return hash_compare_semantic_type (m1, m2);
+}
+
 static inline size_t
 hash_symbol (const symbol *m, size_t tablesize)
 {
@@ -538,12 +644,24 @@ hash_symbol (const symbol *m, size_t tablesize)
   return ((uintptr_t) m->tag) % tablesize;
 }
 
+static inline size_t
+hash_semantic_type (const semantic_type *m, size_t tablesize)
+{
+  /* Since names are unique, we can hash the pointer itself.  */
+  return ((uintptr_t) m->tag) % tablesize;
+}
+
 static size_t
 hash_symbol_hasher (void const *m, size_t tablesize)
 {
   return hash_symbol (m, tablesize);
 }
 
+static size_t
+hash_semantic_type_hasher (void const *m, size_t tablesize)
+{
+  return hash_semantic_type (m, tablesize);
+}
 
 /*-------------------------------.
 | Create the symbol hash table.  |
@@ -557,6 +675,11 @@ symbols_new (void)
 				  hash_symbol_hasher,
 				  hash_symbol_comparator,
 				  free);
+  semantic_type_table = hash_initialize (HT_INITIAL_CAPACITY,
+				         NULL,
+				         hash_semantic_type_hasher,
+				         hash_semantic_type_comparator,
+				         free);
 }
 
 
@@ -584,6 +707,30 @@ symbol_from_uniqstr (const uniqstr key, location loc)
 }
 
 
+/*-----------------------------------------------------------------------.
+| Find the semantic type named KEY, and return it.  If it does not exist |
+| yet, create it.                                                        |
+`-----------------------------------------------------------------------*/
+
+semantic_type *
+semantic_type_from_uniqstr (const uniqstr key)
+{
+  semantic_type probe;
+  semantic_type *entry;
+
+  probe.tag = key;
+  entry = hash_lookup (semantic_type_table, &probe);
+
+  if (!entry)
+    {
+      /* First insertion in the hash. */
+      entry = semantic_type_new (key);
+      hash_insert (semantic_type_table, entry);
+    }
+  return entry;
+}
+
+
 /*----------------------------------------------------------------.
 | Find the symbol named KEY, and return it.  If it does not exist |
 | yet, create it.                                                 |
@@ -596,6 +743,18 @@ symbol_get (const char *key, location loc)
 }
 
 
+/*-----------------------------------------------------------------------.
+| Find the semantic type named KEY, and return it.  If it does not exist |
+| yet, create it.                                                        |
+`-----------------------------------------------------------------------*/
+
+semantic_type *
+semantic_type_get (const char *key)
+{
+  return semantic_type_from_uniqstr (uniqstr_new (key));
+}
+
+
 /*------------------------------------------------------------------.
 | Generate a dummy nonterminal, whose name cannot conflict with the |
 | user's names.                                                     |
@@ -631,6 +790,7 @@ void
 symbols_free (void)
 {
   hash_free (symbol_table);
+  hash_free (semantic_type_table);
   free (symbols);
 }
 

src/symtab.h

@@ -106,7 +106,6 @@ struct symbol
   bool declared;
 };
 
-
 /** Undefined user number.  */
 #define USER_NUMBER_UNDEFINED -1
 
@@ -197,15 +196,51 @@ extern symbol *startsymbol;
 extern location startsymbol_location;
 
 
-/*---------------.
+/*-----------------.
-| Symbol table.  |
+| Semantic types.  |
-`---------------*/
+`-----------------*/
 
+/** A semantic type and its associated \c \%destructor and \c \%printer.
    
-/** Create the symbol table.  */
+   Access the fields of this struct only through the interface functions in
+   this file.  \sa symbol::destructor  */
+typedef struct semantic_type {
+  /** The key, name of the semantic type.  */
+  uniqstr tag;
+
+  /** Any \c %destructor declared for this semantic type.  */
+  const char *destructor;
+  /** The location of \c semantic_type::destructor.  */
+  location destructor_location;
+
+  /** Any \c %printer declared for this semantic type.  */
+  const char *printer;
+  /** The location of \c semantic_type::printer.  */
+  location printer_location;
+} semantic_type;
+
+/** Fetch (or create) the semantic type associated to KEY.  */
+semantic_type *semantic_type_from_uniqstr (const uniqstr key);
+
+/** Fetch (or create) the semantic type associated to KEY.  */
+semantic_type *semantic_type_get (const char *key);
+
+/** Set the \c destructor associated with \c type.  */
+void semantic_type_destructor_set (semantic_type *type, const char *destructor,
+                                   location loc);
+
+/** Set the \c printer associated with \c type.  */
+void semantic_type_printer_set (semantic_type *type, const char *printer,
+                                location loc);
+
+/*----------------------------------.
+| Symbol and semantic type tables.  |
+`----------------------------------*/
+
+/** Create the symbol and semantic type tables.  */
 void symbols_new (void);
 
-/** Free all the memory allocated for symbols.  */
+/** Free all the memory allocated for symbols and semantic types.  */
 void symbols_free (void);
 
 /** Check that all the symbols are defined.

tests/actions.at

@@ -689,6 +689,132 @@ AT_CLEANUP
 
 
 
+## ----------------------------------- ##
+## Per-type %printer and %destructor.  ##
+## ----------------------------------- ##
+
+AT_SETUP([Per-type %printer and %destructor])
+
+AT_DATA_GRAMMAR([[input.y]],
+[[%error-verbose
+%debug
+
+%{
+# include <stdio.h>
+# include <stdlib.h>
+  static void yyerror (const char *msg);
+  static int yylex (void);
+# define USE(SYM)
+%}
+
+%union { int field0; int field1; int field2; }
+%type <field0> start 'a' 'g'
+%type <field1> 'e'
+%type <field2> 'f'
+%printer {
+  fprintf (yyoutput, "%%symbol-default/<field2>/e printer");
+} %symbol-default 'e' <field2>
+%destructor {
+  fprintf (stdout, "%%symbol-default/<field2>/e destructor.\n");
+} %symbol-default 'e' <field2>
+
+%type <field1> 'b'
+%printer { fprintf (yyoutput, "<field1> printer"); } <field1>
+%destructor { fprintf (stdout, "<field1> destructor.\n"); } <field1>
+
+%type <field0> 'c'
+%printer { fprintf (yyoutput, "'c' printer"); } 'c'
+%destructor { fprintf (stdout, "'c' destructor.\n"); } 'c'
+
+%type <field1> 'd'
+%printer { fprintf (yyoutput, "'d' printer"); } 'd'
+%destructor { fprintf (stdout, "'d' destructor.\n"); } 'd'
+
+%%
+
+start:
+  'a' 'b' 'c' 'd' 'e' 'f' 'g'
+    {
+      USE(($1, $2, $3, $4, $5, $6, $7));
+      $$ = 'S';
+    }
+  ;
+
+%%
+
+static int
+yylex (void)
+{
+  static const char *input = "abcdef";
+  return *input++;
+}
+
+static void
+yyerror (const char *msg)
+{
+  fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+  yydebug = 1;
+  return yyparse ();
+}
+]])
+
+AT_CHECK([bison -o input.c input.y])
+AT_COMPILE([input])
+AT_PARSER_CHECK([./input], 1,
+[[%symbol-default/<field2>/e destructor.
+%symbol-default/<field2>/e destructor.
+'d' destructor.
+'c' destructor.
+<field1> destructor.
+%symbol-default/<field2>/e destructor.
+]],
+[[Starting parse
+Entering state 0
+Reading a token: Next token is token 'a' (%symbol-default/<field2>/e printer)
+Shifting token 'a' (%symbol-default/<field2>/e printer)
+Entering state 1
+Reading a token: Next token is token 'b' (<field1> printer)
+Shifting token 'b' (<field1> printer)
+Entering state 3
+Reading a token: Next token is token 'c' ('c' printer)
+Shifting token 'c' ('c' printer)
+Entering state 5
+Reading a token: Next token is token 'd' ('d' printer)
+Shifting token 'd' ('d' printer)
+Entering state 6
+Reading a token: Next token is token 'e' (%symbol-default/<field2>/e printer)
+Shifting token 'e' (%symbol-default/<field2>/e printer)
+Entering state 7
+Reading a token: Next token is token 'f' (%symbol-default/<field2>/e printer)
+Shifting token 'f' (%symbol-default/<field2>/e printer)
+Entering state 8
+Reading a token: Now at end of input.
+syntax error, unexpected $end, expecting 'g'
+Error: popping token 'f' (%symbol-default/<field2>/e printer)
+Stack now 0 1 3 5 6 7
+Error: popping token 'e' (%symbol-default/<field2>/e printer)
+Stack now 0 1 3 5 6
+Error: popping token 'd' ('d' printer)
+Stack now 0 1 3 5
+Error: popping token 'c' ('c' printer)
+Stack now 0 1 3
+Error: popping token 'b' (<field1> printer)
+Stack now 0 1
+Error: popping token 'a' (%symbol-default/<field2>/e printer)
+Stack now 0
+Cleanup: discarding lookahead token $end ()
+Stack now 0
+]])
+
+AT_CLEANUP
+
+
+
 ## ------------------------------------------------------------- ##
 ## Default %printer and %destructor for user-defined end token. ##
 ## ------------------------------------------------------------- ##

tests/input.at

@@ -175,8 +175,8 @@ AT_CLEANUP
 AT_SETUP([Default %printer and %destructor redeclared])
 
 AT_DATA([[input.y]],
-[[%destructor { destroy ($$); } %symbol-default
+[[%destructor { destroy ($$); } %symbol-default %symbol-default
-%printer { destroy ($$); } %symbol-default
+%printer { destroy ($$); } %symbol-default %symbol-default
 
 %destructor { destroy ($$); } %symbol-default
 %printer { destroy ($$); } %symbol-default
@@ -190,7 +190,11 @@ start: ;
 ]])
 
 AT_CHECK([bison input.y], [1], [],
-[[input.y:4.13-29: redeclaration for default %destructor
+[[input.y:1.13-29: redeclaration for default %destructor
+input.y:1.13-29: previous declaration
+input.y:2.10-26: redeclaration for default %printer
+input.y:2.10-26: previous declaration
+input.y:4.13-29: redeclaration for default %destructor
 input.y:1.13-29: previous declaration
 input.y:5.10-26: redeclaration for default %printer
 input.y:2.10-26: previous declaration
@@ -203,6 +207,49 @@ input.y:5.10-26: previous declaration
 AT_CLEANUP
 
 
+## ---------------------------------------------- ##
+## Per-type %printer and %destructor redeclared.  ##
+## ---------------------------------------------- ##
+
+AT_SETUP([Per-type %printer and %destructor redeclared])
+
+AT_DATA([[input.y]],
+[[%destructor { destroy ($$); } <field1> <field2>
+%printer { destroy ($$); } <field1> <field2>
+
+%destructor { destroy ($$); } <field1> <field1>
+%printer { destroy ($$); } <field2> <field2>
+
+%%
+
+start: ;
+
+%destructor { destroy ($$); } <field2> <field1>;
+%printer { destroy ($$); } <field2> <field1>;
+]])
+
+AT_CHECK([bison input.y], [1], [],
+[[input.y:4.13-29: %destructor redeclaration for <field1>
+input.y:1.13-29: previous declaration
+input.y:4.13-29: %destructor redeclaration for <field1>
+input.y:4.13-29: previous declaration
+input.y:5.10-26: %printer redeclaration for <field2>
+input.y:2.10-26: previous declaration
+input.y:5.10-26: %printer redeclaration for <field2>
+input.y:5.10-26: previous declaration
+input.y:11.13-29: %destructor redeclaration for <field1>
+input.y:4.13-29: previous declaration
+input.y:11.13-29: %destructor redeclaration for <field2>
+input.y:1.13-29: previous declaration
+input.y:12.10-26: %printer redeclaration for <field1>
+input.y:2.10-26: previous declaration
+input.y:12.10-26: %printer redeclaration for <field2>
+input.y:5.10-26: previous declaration
+]])
+
+AT_CLEANUP
+
+
 ## ---------------------------------------- ##
 ## Unused values with default %destructor.  ##
 ## ---------------------------------------- ##
@@ -227,6 +274,31 @@ input.y:6.6-8: warning: unset value: $$
 AT_CLEANUP
 
 
+## ----------------------------------------- ##
+## Unused values with per-type %destructor.  ##
+## ----------------------------------------- ##
+
+AT_SETUP([Unused values with per-type %destructor])
+
+AT_DATA([[input.y]],
+[[%destructor { destroy ($$); } <field1>
+%type <field1> start end
+
+%%
+
+start: end end { $1; } ;
+end: { }  ;
+]])
+
+AT_CHECK([bison input.y], [0], [],
+[[input.y:6.8-22: warning: unset value: $$
+input.y:6.8-22: warning: unused value: $2
+input.y:7.6-8: warning: unset value: $$
+]])
+
+AT_CLEANUP
+
+
 ## ---------------------- ##
 ## Incompatible Aliases.  ##
 ## ---------------------- ##