gcc/cpphash.h

   1 /* Part of CPP library.  (Macro hash table support.)
   2    Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
   3
   4 This program is free software; you can redistribute it and/or modify it
   5 under the terms of the GNU General Public License as published by the
   6 Free Software Foundation; either version 2, or (at your option) any
   7 later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* different kinds of things that can appear in the value field
  19    of a hash node. */
  20 union hashval
  21 {
  22   const char *cpval;            /* some predefined macros */
  23   DEFINITION *defn;             /* #define */
  24   struct hashnode *aschain;     /* #assert */
  25 };
  26
  27 struct hashnode {
  28   struct hashnode *next;        /* double links for easy deletion */
  29   struct hashnode *prev;
  30   struct hashnode **bucket_hdr; /* also, a back pointer to this node's hash
  31                                    chain is kept, in case the node is the head
  32                                    of the chain and gets deleted. */
  33   enum node_type type;          /* type of special token */
  34   int length;                   /* length of token, for quick comparison */
  35   U_CHAR *name;                 /* the actual name */
  36   union hashval value;          /* pointer to expansion, or whatever */
  37 };
  38
  39 typedef struct hashnode HASHNODE;
  40
  41 /* Some definitions for the hash table.  The hash function MUST be
  42    computed as shown in hashf () below.  That is because the rescan
  43    loop computes the hash value `on the fly' for most tokens,
  44    in order to avoid the overhead of a lot of procedure calls to
  45    the hashf () function.  Hashf () only exists for the sake of
  46    politeness, for use when speed isn't so important. */
  47
  48 #define HASHSTEP(old, c) ((old << 2) + c)
  49 #define MAKE_POS(v) (v & 0x7fffffff) /* make number positive */
  50
  51 extern HASHNODE *cpp_install      PARAMS ((cpp_reader *, const U_CHAR *, int,
  52                                            enum node_type, const char *, int));
  53 extern int hashf                  PARAMS ((const U_CHAR *, int, int));
  54 extern void delete_macro          PARAMS ((HASHNODE *));
  55
  56 extern MACRODEF create_definition PARAMS ((U_CHAR *, U_CHAR *,
  57                                            cpp_reader *, int));
  58 extern int compare_defs           PARAMS ((cpp_reader *, DEFINITION *,
  59                                            DEFINITION *));
  60 extern void macroexpand           PARAMS ((cpp_reader *, HASHNODE *));
  61 extern void dump_definition       PARAMS ((cpp_reader *, MACRODEF));