X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/22dda0f00476e140b490979a3894d75ebc45b0cb..16832bf546d0d846081ef193e56931b1ebe7e4ab:/src/symtab.h

diff --git a/src/symtab.h b/src/symtab.h
index 61caa539..f92407f8 100644
--- a/src/symtab.h
+++ b/src/symtab.h
@@ -1,70 +1,115 @@
 /* Definitions for symtab.c and callers, part of Bison.
 
-   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2004, 2005
-   Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989, 1992, 2000-2002, 2004-2015 Free Software
+   Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
-   Bison is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
 
-   Bison is distributed in the hope that it will be useful,
+   This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with Bison; see the file COPYING.  If not, write to
-   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-   Boston, MA 02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/**
+ * \file symtab.h
+ * \brief Manipulating ::symbol.
+ */
 
 #ifndef SYMTAB_H_
 # define SYMTAB_H_
 
 # include "assoc.h"
 # include "location.h"
+# include "scan-code.h"
 # include "uniqstr.h"
 
 /*----------.
 | Symbols.  |
 `----------*/
 
-/* Symbol classes.  */
+/** Symbol classes.  */
 typedef enum
 {
-  unknown_sym,
-  token_sym,		/* terminal symbol */
-  nterm_sym		/* non-terminal */
+  unknown_sym,          /**< Undefined.  */
+  token_sym,            /**< Terminal. */
+  nterm_sym             /**< Non-terminal. */
 } symbol_class;
 
 
-/* Internal token numbers. */
+/** Internal token numbers. */
 typedef int symbol_number;
-#define SYMBOL_NUMBER_MAXIMUM INT_MAX
+# define SYMBOL_NUMBER_MAXIMUM INT_MAX
 
 
 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" but used in
+   a rule, it is "needed".  Finally, if declared (via a rule for
+   nonterminals, or %token), 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;
+
+enum code_props_type
+  {
+    destructor = 0,
+    printer = 1,
+  };
+typedef enum code_props_type code_props_type;
+
+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.  */
+  /** The key, name of the symbol.  */
   uniqstr tag;
-  /* The location of its first occurrence.  */
+  /** The location of its first occurrence.  */
   location location;
 
-  /* Its %type and associated printer and destructor.  */
+  /** Its \c \%type.
+
+      Beware that this is the type_name as was entered by the user,
+      including silly things such as "]" if she entered "%token <]> t".
+      Therefore, when outputting type_name to M4, be sure to escape it
+      into "@}".  See quoted_output for instance.  */
   uniqstr type_name;
+
+  /** Its \c \%type's location.  */
   location type_location;
 
-  char *destructor;
-  location destructor_location;
+  /** Any \c \%destructor (resp. \%printer) declared specificially for this
+      symbol.
 
-  char *printer;
-  location printer_location;
+      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 correct one. */
+  code_props props[CODE_PROPS_SIZE];
 
   symbol_number number;
   location prec_location;
@@ -72,87 +117,222 @@ struct symbol
   assoc assoc;
   int user_token_number;
 
-  /* Points to the other in the identifier-symbol pair for an alias.
-     Special value USER_NUMBER_ALIAS in the identifier half of the
-     identifier-symbol pair for an alias.  */
+  /* 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
+/** Undefined user number.  */
+# define USER_NUMBER_UNDEFINED -1
 
-/* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
-   *has* (not is) a string literal alias.  For instance, `%token foo
-   "foo"' has `"foo"' numbered regularly, and `foo' numbered as
-   USER_NUMBER_ALIAS.  */
-#define USER_NUMBER_ALIAS -9991
+/* '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)
+# define NUMBER_UNDEFINED (-1)
 
-/* Print a symbol (for debugging). */
-void symbol_print (symbol *s, FILE *f);
+/** 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.  */
+/** Fetch (or create) the symbol associated to KEY.  */
 symbol *symbol_get (const char *key, location loc);
 
-/* Generate a dummy nonterminal, whose name cannot conflict with the
-   user's names.  */
+/** Generate a dummy nonterminal.
+
+   Its name cannot conflict with the user's names.  */
 symbol *dummy_symbol_get (location loc);
 
-/* Declare the new symbol SYM.  Make it an alias of SYMVAL.  */
-void symbol_make_alias (symbol *sym, symbol *symval, location loc);
 
-/* Set the TYPE_NAME associated with SYM.  Do nothing if passed 0 as
-   TYPE_NAME.  */
+/*--------------------.
+| Methods on symbol.  |
+`--------------------*/
+
+/** Print a symbol (for debugging). */
+void symbol_print (symbol const *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 DESTRUCTOR associated with SYM.  */
-void symbol_destructor_set (symbol *sym, char *destructor, 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);
 
-/* Set the PRINTER associated with SYM.  */
-void symbol_printer_set (symbol *sym, char *printer, location loc);
+/** 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 *symbol_code_props_get (symbol *sym, code_props_type kind);
 
-/* Set the PRECEDENCE associated with SYM.  Ensure that SYMBOL is a
-   terminal.  Do nothing if invoked with UNDEF_ASSOC as ASSOC.  */
+/** 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 CLASS associated with SYM.  */
-void symbol_class_set (symbol *sym, symbol_class class, 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 USER_TOKEN_NUMBER associated with SYM.  */
+/** Set the \c user_token_number associated with \c sym.  */
 void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
 
 
-/* Distinguished symbols.  AXIOM is the real start symbol, that used
-   by the automaton.  STARTSYMBOL is the one specified by the user.
-   */
+
+/*------------------.
+| 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;
 
 
-/*---------------.
-| Symbol table.  |
-`---------------*/
 
+/*-------------------.
+| Symbol Relations.  |
+`-------------------*/
+
+/* The symbol relations are represented by a directed graph. */
+
+/* The id of a node */
+typedef int graphid;
+
+typedef struct symgraphlink symgraphlink;
+
+struct symgraphlink
+{
+  /** The second \c symbol or group of a precedence relation.
+   * See \c symgraph. */
+  graphid id;
+
+  symgraphlink *next;
+};
+
+/* Symbol precedence graph, to store the used precedence relations between
+ * symbols. */
+
+typedef struct symgraph symgraph;
+
+struct symgraph
+{
+  /** Identifier for the node: equal to the number of the symbol. */
+  graphid id;
+
+  /** The list of related symbols that have a smaller precedence. */
+  symgraphlink *succ;
+
+  /** The list of related symbols that have a greater precedence. */
+  symgraphlink *pred;
+};
+
+/** Register a new precedence relation as used. */
+
+void register_precedence (graphid first, graphid snd);
+
+/** Print a warning for each symbol whose precedence and/or associativity
+ * is useless. */
+
+void print_precedence_warnings (void);
+
+/*----------------------.
+| Symbol associativity  |
+`----------------------*/
+
+void register_assoc (graphid i, graphid j);
+
+/*-----------------.
+| Semantic types.  |
+`-----------------*/
 
-/* Create the symbol table.  */
+/** 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;
+
+  /** The location of its first occurence.  */
+  location location;
+
+  /** Its status : "undeclared", "used" or "declared".
+      It cannot be "needed".  */
+  status status;
+
+  /** 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,
+                                           const location *loc);
+
+/** Fetch (or create) the semantic type associated to KEY.  */
+semantic_type *semantic_type_get (const char *key, const location *loc);
+
+/** 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.  */
+/** 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.  */
+/** Check that all the symbols are defined.
+
+    Report any undefined symbols and consider them nonterminals.  */
 void symbols_check_defined (void);
 
-/* Perform various sanity checks, assign symbol numbers, and set up
-   TOKEN_TRANSLATIONS.  */
+/** Sanity checks and #token_translations construction.
+
+   Perform various sanity checks, assign symbol numbers, and set up
+   #token_translations.  */
 void symbols_pack (void);
 
 #endif /* !SYMTAB_H_ */