gcc/cpphash.c

   1 /* Hash tables for the CPP library.
   2    Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1998,
   3    1999, 2000, 2001, 2002 Free Software Foundation, Inc.
   4    Written by Per Bothner, 1994.
   5    Based on CCCP program by Paul Rubin, June 1986
   6    Adapted to ANSI C, Richard Stallman, Jan 1987
   7
   8 This program is free software; you can redistribute it and/or modify it
   9 under the terms of the GNU General Public License as published by the
  10 Free Software Foundation; either version 2, or (at your option) any
  11 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, write to the Free Software
  20 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21
  22  In other words, you are welcome to use, share and improve this program.
  23  You are forbidden to forbid anyone else to use, share and improve
  24  what you give them.   Help stamp out software-hoarding!  */
  25
  26 #include "config.h"
  27 #include "system.h"
  28 #include "cpplib.h"
  29 #include "cpphash.h"
  30
  31 static cpp_hashnode *alloc_node PARAMS ((hash_table *));
  32
  33 /* Return an identifier node for hashtable.c.  Used by cpplib except
  34    when integrated with the C front ends.  */
  35 static cpp_hashnode *
  36 alloc_node (table)
  37      hash_table *table;
  38 {
  39   cpp_hashnode *node;
  40
  41   node = (cpp_hashnode *) obstack_alloc (&table->pfile->hash_ob,
  42                                          sizeof (cpp_hashnode));
  43   memset ((PTR) node, 0, sizeof (cpp_hashnode));
  44   return node;
  45 }
  46
  47 /* Set up the identifier hash table.  Use TABLE if non-null, otherwise
  48    create our own.  */
  49 void
  50 _cpp_init_hashtable (pfile, table)
  51      cpp_reader *pfile;
  52      hash_table *table;
  53 {
  54   struct spec_nodes *s;
  55
  56   if (table == NULL)
  57     {
  58       pfile->our_hashtable = 1;
  59       table = ht_create (13);   /* 8K (=2^13) entries.  */
  60       table->alloc_node = (hashnode (*) PARAMS ((hash_table *))) alloc_node;
  61       gcc_obstack_init (&pfile->hash_ob);
  62     }
  63
  64   table->pfile = pfile;
  65   pfile->hash_table = table;
  66
  67   /* Now we can initialize things that use the hash table.  */
  68   _cpp_init_directives (pfile);
  69   _cpp_init_internal_pragmas (pfile);
  70
  71   s = &pfile->spec_nodes;
  72   s->n_defined          = cpp_lookup (pfile, DSC("defined"));
  73   s->n_true             = cpp_lookup (pfile, DSC("true"));
  74   s->n_false            = cpp_lookup (pfile, DSC("false"));
  75   s->n__STRICT_ANSI__   = cpp_lookup (pfile, DSC("__STRICT_ANSI__"));
  76   s->n__VA_ARGS__       = cpp_lookup (pfile, DSC("__VA_ARGS__"));
  77   s->n__VA_ARGS__->flags |= NODE_DIAGNOSTIC;
  78 }
  79
  80 /* Tear down the identifier hash table.  */
  81 void
  82 _cpp_destroy_hashtable (pfile)
  83      cpp_reader *pfile;
  84 {
  85   if (pfile->our_hashtable)
  86     {
  87       ht_destroy (pfile->hash_table);
  88       obstack_free (&pfile->hash_ob, 0);
  89     }
  90 }
  91
  92 /* Returns the hash entry for the STR of length LEN, creating one
  93    if necessary.  */
  94 cpp_hashnode *
  95 cpp_lookup (pfile, str, len)
  96      cpp_reader *pfile;
  97      const unsigned char *str;
  98      unsigned int len;
  99 {
 100   /* ht_lookup cannot return NULL.  */
 101   return CPP_HASHNODE (ht_lookup (pfile->hash_table, str, len, HT_ALLOC));
 102 }
 103
 104 /* Determine whether the str STR, of length LEN, is a defined macro.  */
 105 int
 106 cpp_defined (pfile, str, len)
 107      cpp_reader *pfile;
 108      const unsigned char *str;
 109      int len;
 110 {
 111   cpp_hashnode *node;
 112
 113   node = CPP_HASHNODE (ht_lookup (pfile->hash_table, str, len, HT_NO_INSERT));
 114
 115   /* If it's of type NT_MACRO, it cannot be poisoned.  */
 116   return node && node->type == NT_MACRO;
 117 }
 118
 119 /* For all nodes in the hashtable, callback CB with parameters PFILE,
 120    the node, and V.  */
 121 void
 122 cpp_forall_identifiers (pfile, cb, v)
 123      cpp_reader *pfile;
 124      cpp_cb cb;
 125      PTR v;
 126 {
 127   /* We don't need a proxy since the hash table's identifier comes
 128      first in cpp_hashnode.  */
 129   ht_forall (pfile->hash_table, (ht_cb) cb, v);
 130 }