X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/2073e1b6023bef516150070c8fd8239a1d8f873e..b2a0b7ca70f9490693d517d10c9c4a64c9fc1af0:/src/symtab.h

diff --git a/src/symtab.h b/src/symtab.h
index 00770a6e..243d3d0c 100644
--- a/src/symtab.h
+++ b/src/symtab.h
@@ -61,16 +61,35 @@ struct symbol
   /** The location of its first occurrence.  */
   location location;
 
-  /** Its %type and associated printer and destructor.  */
+  /** Its \c \%type.  */
   uniqstr type_name;
+  /** Its \c \%type's location.  */
   location type_location;
 
-  /** Does not own the memory. */
+  /** Any \c \%destructor declared specifically for this symbol.
+
+     Access this field only through <tt>symbol</tt>'s interface functions.  For
+     example, if <tt>symbol::destructor = NULL</tt>, the default
+     \c \%destructor or a per-type \c \%destructor might be appropriate, and
+     \c symbol_destructor_get will compute the correct one.  */
   const char *destructor;
+
+  /** The location of \c symbol::destructor.
+
+     Access this field only through <tt>symbol</tt>'s interface functions.
+     \sa symbol::destructor  */
   location destructor_location;
 
-  /** Printer. */
+  /** Any \c \%printer declared specifically for this symbol.
+
+     Access this field only through <tt>symbol</tt>'s interface functions.
+     \sa symbol::destructor  */
   const char *printer;
+
+  /** The location of \c symbol::printer.
+
+     Access this field only through <tt>symbol</tt>'s interface functions.
+     \sa symbol::destructor  */
   location printer_location;
 
   symbol_number number;
@@ -87,7 +106,6 @@ struct symbol
   bool declared;
 };
 
-
 /** Undefined user number.  */
 #define USER_NUMBER_UNDEFINED -1
 
@@ -114,6 +132,9 @@ symbol *symbol_get (const char *key, location loc);
    Its name cannot conflict with the user's names.  */
 symbol *dummy_symbol_get (location loc);
 
+/** Is this a dummy nonterminal?  */
+bool symbol_is_dummy (const symbol *sym);
+
 /** Declare the new symbol \c sym.  Make it an alias of \c symval.  */
 void symbol_make_alias (symbol *sym, symbol *symval, location loc);
 
@@ -125,9 +146,25 @@ void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
 /** Set the \c destructor associated with \c sym.  */
 void symbol_destructor_set (symbol *sym, const char *destructor, location loc);
 
+/** Get the computed \c \%destructor for \c sym, or \c NULL if none.   */
+const char *symbol_destructor_get (symbol *sym);
+
+/** Get the grammar location of the computed \c \%destructor for \c sym.
+ 
+  \pre <tt>symbol_destructor_get (sym) != NULL</tt> */
+location symbol_destructor_location_get (symbol *sym);
+
 /** Set the \c printer associated with \c sym.  */
 void symbol_printer_set (symbol *sym, const char *printer, location loc);
 
+/** Get the computed \c \%printer for \c sym, or \c NULL if none.  */
+const char *symbol_printer_get (symbol *sym);
+
+/** Get the grammar location of the computed \c \%printer for \c sym.
+
+  \pre <tt>symbol_printer_get (sym) != NULL</tt> */
+location symbol_printer_location_get (symbol *sym);
+
 /* Set the \c precedence associated with \c sym.
 
    Ensure that \a symbol is a terminal.
@@ -155,19 +192,55 @@ extern symbol *accept;
 
 /** The user start symbol. */
 extern symbol *startsymbol;
-/** The location of the \c %start declaration.  */
+/** The location of the \c \%start declaration.  */
 extern location startsymbol_location;
 
 
-/*---------------.
-| Symbol table.  |
-`---------------*/
+/*-----------------.
+| Semantic types.  |
+`-----------------*/
 
+/** A semantic type and its associated \c \%destructor and \c \%printer.
+   
+   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;
 
-/** Create the symbol table.  */
+  /** 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.
@@ -181,4 +254,15 @@ void symbols_check_defined (void);
    #token_translations.  */
 void symbols_pack (void);
 
+
+/*-----------------------------------.
+| Default %destructor and %printer.  |
+`-----------------------------------*/
+
+/** Set the default \c \%destructor.  */
+void default_destructor_set (const char *destructor, location loc);
+
+/** Set the default \c \%printer.  */
+void default_printer_set (const char *printer, location loc);
+
 #endif /* !SYMTAB_H_ */