+typedef struct symbol symbol;
+
+/* Declaration status of a symbol.
+
+ First, it is "undeclared". Then, if "undeclared" and used in a
+ %printer/%destructor, it is "used". If not "declared" by used in a
+ rule, it is "needed". Finally, if declared (via a rule for
+ nonterminals, or %oken), it is "declared".
+
+ When status are checked at the end, "declared" symbols are fine,
+ "used" symbols trigger warnings, otherwise it's an error.
+*/
+
+typedef enum
+ {
+ /** Used in the input file for an unknown reason (error). */
+ undeclared,
+ /** Used by %destructor/%printer but not defined (warning). */
+ used,
+ /** Used in the gramar (rules) but not defined (error). */
+ needed,
+ /** Defined with %type or %token (good). */
+ declared,
+ } status;
+
+typedef enum code_props_type code_props_type;
+enum code_props_type
+ {
+ destructor = 0,
+ printer = 1,
+ };
+
+enum { CODE_PROPS_SIZE = 2 };
+
+/* When extending this structure, be sure to complete
+ symbol_check_alias_consistency. */
+struct symbol
+{
+ /** The key, name of the symbol. */
+ uniqstr tag;
+ /** The location of its first occurrence. */
+ location location;
+
+ /** Its \c \%type. */
+ uniqstr type_name;
+ /** Its \c \%type's location. */
+ location type_location;
+
+ /** Any \c \%destructor (resp. \%printer) declared specificially for this
+ symbol.
+
+ Access this field only through <tt>symbol</tt>'s interface functions. For
+ Example, if <tt>symbol::destructor = NULL</tt> (resp. <tt>symbol::printer
+ = NULL</tt>), a default \c \%destructor (resp. \%printer) or a per-type
+ \c symbol_destructor_printer_get will compute the corect one. */
+ code_props props[CODE_PROPS_SIZE];
+
+ symbol_number number;
+ location prec_location;
+ int prec;
+ assoc assoc;
+ int user_token_number;
+
+ /* Points to the other in the symbol-string pair for an alias.
+ Special value USER_NUMBER_HAS_STRING_ALIAS in the symbol half of the
+ symbol-string pair for an alias. */
+ symbol *alias;
+ symbol_class class;
+ status status;
+};
+
+/** Undefined user number. */
+#define USER_NUMBER_UNDEFINED -1
+
+/* `symbol->user_token_number == USER_NUMBER_HAS_STRING_ALIAS' means
+ this symbol has a literal string alias. For instance, `%token foo
+ "foo"' has `"foo"' numbered regularly, and `foo' numbered as
+ USER_NUMBER_HAS_STRING_ALIAS. */
+#define USER_NUMBER_HAS_STRING_ALIAS -9991
+
+/* Undefined internal token number. */
+#define NUMBER_UNDEFINED (-1)
+
+/** Fetch (or create) the symbol associated to KEY. */
+symbol *symbol_from_uniqstr (const uniqstr key, location loc);
+
+/** Fetch (or create) the symbol associated to KEY. */
+symbol *symbol_get (const char *key, location loc);
+
+/** Generate a dummy nonterminal.
+
+ Its name cannot conflict with the user's names. */
+symbol *dummy_symbol_get (location loc);
+
+
+/*--------------------.
+| Methods on symbol. |
+`--------------------*/
+
+/** Print a symbol (for debugging). */
+void symbol_print (symbol *s, FILE *f);
+
+/** Is this a dummy nonterminal? */
+bool symbol_is_dummy (const symbol *sym);
+
+/** The name of the code_props type: "\%destructor" or "\%printer". */
+char const *code_props_type_string (code_props_type kind);
+
+/** The name of the symbol that can be used as an identifier.
+ ** Consider the alias if needed.
+ ** Return 0 if there is none (e.g., the symbol is only defined as
+ ** a string). */
+uniqstr symbol_id_get (symbol const *sym);
+
+/**
+ * Make \c str the literal string alias of \c sym. Copy token number,
+ * symbol number, and type from \c sym to \c str.
+ */
+void symbol_make_alias (symbol *sym, symbol *str, location loc);
+
+/** Set the \c type_name associated with \c sym.
+
+ Do nothing if passed 0 as \c type_name. */
+void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
+
+/** Set the \c \%destructor or \c \%printer associated with \c sym. */
+void symbol_code_props_set (symbol *sym, code_props_type kind,
+ code_props const *destructor);
+
+/** Get the computed \c \%destructor or \c %printer for \c sym, which was
+initialized with \c code_props_none_init if there's no \c \%destructor or
+\c %printer. */
+code_props const *symbol_code_props_get (symbol const *sym,
+ code_props_type kind);
+
+/* Set the \c precedence associated with \c sym.
+
+ Ensure that \a symbol is a terminal.
+ Do nothing if invoked with \c undef_assoc as \c assoc. */
+void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
+
+/** Set the \c class associated with \c sym. */
+void symbol_class_set (symbol *sym, symbol_class class, location loc,
+ bool declaring);
+
+/** Set the \c user_token_number associated with \c sym. */
+void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
+
+
+
+/*------------------.
+| Special symbols. |
+`------------------*/
+
+/** The error token. */
+extern symbol *errtoken;
+/** The token for unknown tokens. */
+extern symbol *undeftoken;
+/** The end of input token. */
+extern symbol *endtoken;
+/** The genuine start symbol.
+
+ $accept: start-symbol $end */
+extern symbol *accept;
+
+/** The user start symbol. */
+extern symbol *startsymbol;
+/** The location of the \c \%start declaration. */
+extern location startsymbol_location;
+
+
+/*-----------------.
+| 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 {
+ /** The key, name of the semantic type. */
+ uniqstr tag;
+
+ /** Any \c %destructor and %printer declared for this
+ semantic type. */
+ code_props props[CODE_PROPS_SIZE];
+
+} 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 or \c printer associated with \c type. */
+void semantic_type_code_props_set (semantic_type *type,
+ code_props_type kind,
+ code_props const *code);
+
+/*----------------------------------.
+| Symbol and semantic type tables. |
+`----------------------------------*/
+
+/** Create the symbol and semantic type tables. */
+void symbols_new (void);
+
+/** Free all the memory allocated for symbols and semantic types. */
+void symbols_free (void);
+
+/** Check that all the symbols are defined.
+
+ Report any undefined symbols and consider them nonterminals. */
+void symbols_check_defined (void);
+
+/** Sanity checks and #token_translations construction.
+
+ Perform various sanity checks, assign symbol numbers, and set up
+ #token_translations. */
+void symbols_pack (void);
+
+
+/*---------------------------------------.
+| Default %destructor's and %printer's. |
+`---------------------------------------*/
+
+/** Set the default \c \%destructor or \c \%printer for tagged values. */
+void default_tagged_code_props_set (code_props_type kind,
+ code_props const *code);
+/** Set the default \c \%destructor or \c \%printer for tagless values. */
+void default_tagless_code_props_set (code_props_type kind,
+ code_props const *destructor);
+
+#endif /* !SYMTAB_H_ */