src/symlist.h

   1 /* Lists of symbols for Bison
   2
   3    Copyright (C) 2002, 2005-2007, 2009-2015, 2018-2021 Free Software
   4    Foundation, Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    This program is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  20
  21 #ifndef SYMLIST_H_
  22 # define SYMLIST_H_
  23
  24 # include "location.h"
  25 # include "scan-code.h"
  26 # include "symtab.h"
  27 # include "named-ref.h"
  28
  29 /* A list of symbols, used during the parsing for many different
  30    purposes: rules, symbol declarations or properties (such as
  31    %destructor, etc.)...  */
  32 typedef struct symbol_list
  33 {
  34   /**
  35    * Whether this node contains a symbol, a semantic type, a \c <*>, or a
  36    * \c <>.
  37    */
  38   enum {
  39     SYMLIST_SYMBOL,
  40     SYMLIST_TYPE
  41   } content_type;
  42   union {
  43     /**
  44      * The symbol or \c NULL iff
  45      * <tt>symbol_list::content_type = SYMLIST_SYMBOL</tt>.
  46      */
  47     symbol *sym;
  48     /**
  49      * The semantic type iff <tt>symbol_list::content_type = SYMLIST_TYPE</tt>.
  50      */
  51     semantic_type *sem_type;
  52   } content;
  53
  54   /* Named reference. */
  55   named_ref *named_ref;
  56
  57   /* Proper location of the symbol, not all the rule */
  58   location sym_loc;
  59
  60   /* If this symbol is the generated lhs for a midrule but this is the rule in
  61      whose rhs it appears, MIDRULE = a pointer to that midrule.  */
  62   struct symbol_list *midrule;
  63
  64   /* If this symbol is the generated lhs for a midrule and this is that
  65      midrule, MIDRULE_PARENT_RULE = a pointer to the rule in whose rhs it
  66      appears, and MIDRULE_PARENT_RHS_INDEX = its rhs index (1-origin) in the
  67      parent rule.  */
  68   struct symbol_list *midrule_parent_rule;
  69   int midrule_parent_rhs_index;
  70
  71   /*--------------------------------------------------------------.
  72   | Used for rules only (attached to the "LHS", one per rule even |
  73   | when several RHSs are bound to a single lhs via "|").         |
  74   `--------------------------------------------------------------*/
  75
  76   /* Location of the RHS. */
  77   location rhs_loc;
  78
  79   /* Precedence/associativity.  */
  80   symbol *ruleprec;
  81
  82   /* The action is attached to the LHS of a rule, but action properties for
  83    * each RHS are also stored here.  */
  84   code_props action_props;
  85
  86   /* The location of the first %empty for this rule, or \a
  87      empty_loc.  */
  88   location percent_empty_loc;
  89
  90   int dprec;
  91   location dprec_loc;
  92   int merger;
  93   location merger_declaration_loc;
  94
  95   /* Counts of the number of expected conflicts for this rule, or -1 if none
  96      given. */
  97   int expected_sr_conflicts;
  98   int expected_rr_conflicts;
  99
 100   /* The list.  */
 101   struct symbol_list *next;
 102 } symbol_list;
 103
 104
 105 /** Create a list containing \c sym at \c loc.  */
 106 symbol_list *symbol_list_sym_new (symbol *sym, location loc);
 107
 108 /** Create a list containing \c type_name at \c loc.  */
 109 symbol_list *symbol_list_type_new (uniqstr type_name, location loc);
 110
 111 /** Assign the type \c type_name to all the members of \c syms.
 112  ** \returns \c syms */
 113 symbol_list *symbol_list_type_set (symbol_list *syms, uniqstr type_name);
 114
 115 /** Print this list.
 116
 117   \pre For every node \c n in the list, <tt>n->content_type =
 118   SYMLIST_SYMBOL</tt>.  */
 119 void symbol_list_syms_print (const symbol_list *l, FILE *f);
 120
 121 /** Prepend \c node to \c list.  */
 122 symbol_list *symbol_list_prepend (symbol_list *list, symbol_list *node);
 123
 124 /** Append \c node to \c list.  */
 125 symbol_list *symbol_list_append (symbol_list *list, symbol_list *node);
 126
 127 /** Free \c list, but not the items it contains.  */
 128 void symbol_list_free (symbol_list *list);
 129
 130 /** Return the length of \c l. */
 131 int symbol_list_length (symbol_list const *l);
 132
 133 /** Get item \c n in symbol list \c l.
 134  ** \pre  0 <= n
 135  ** \post res != NULL
 136  **/
 137 symbol_list *symbol_list_n_get (symbol_list *l, int n);
 138
 139 /* Get the data type (alternative in the union) of the value for
 140    symbol N in rule RULE.  */
 141 uniqstr symbol_list_n_type_name_get (symbol_list *l, int n);
 142
 143 /* Check whether the node is a border element of a rule. */
 144 bool symbol_list_null (symbol_list *node);
 145
 146 /** Set the \c \%destructor or \c \%printer for \c node as \c cprops.  */
 147 void symbol_list_code_props_set (symbol_list *node, code_props_type kind,
 148                                  code_props const *cprops);
 149
 150 #endif /* !SYMLIST_H_ */