1 /* Hash tables for the CPP library. 2 Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1998, 3 1999, 2000, 2001, 2002, 2007, 2009 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 3, 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; see the file COPYING3. If not see 20 <http://www.gnu.org/licenses/>. 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 "internal.h" 30 31 static hashnode alloc_node (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 hashnode 36 alloc_node (hash_table *table) 37 { 38 cpp_hashnode *node; 39 40 node = XOBNEW (&table->pfile->hash_ob, cpp_hashnode); 41 memset (node, 0, sizeof (cpp_hashnode)); 42 return HT_NODE (node); 43 } 44 45 /* Set up the identifier hash table. Use TABLE if non-null, otherwise 46 create our own. */ 47 void 48 _cpp_init_hashtable (cpp_reader *pfile, hash_table *table) 49 { 50 struct spec_nodes *s; 51 52 if (table == NULL) 53 { 54 pfile->our_hashtable = 1; 55 table = ht_create (13); /* 8K (=2^13) entries. */ 56 table->alloc_node = alloc_node; 57 58 _obstack_begin (&pfile->hash_ob, 0, 0, 59 (void *(*) (long)) xmalloc, 60 (void (*) (void *)) free); 61 } 62 63 table->pfile = pfile; 64 pfile->hash_table = table; 65 66 /* Now we can initialize things that use the hash table. */ 67 _cpp_init_directives (pfile); 68 _cpp_init_internal_pragmas (pfile); 69 70 s = &pfile->spec_nodes; 71 s->n_defined = cpp_lookup (pfile, DSC("defined")); 72 s->n_true = cpp_lookup (pfile, DSC("true")); 73 s->n_false = cpp_lookup (pfile, DSC("false")); 74 s->n__VA_ARGS__ = cpp_lookup (pfile, DSC("__VA_ARGS__")); 75 s->n__VA_ARGS__->flags |= NODE_DIAGNOSTIC; 76 } 77 78 /* Tear down the identifier hash table. */ 79 void 80 _cpp_destroy_hashtable (cpp_reader *pfile) 81 { 82 if (pfile->our_hashtable) 83 { 84 ht_destroy (pfile->hash_table); 85 obstack_free (&pfile->hash_ob, 0); 86 } 87 } 88 89 /* Returns the hash entry for the STR of length LEN, creating one 90 if necessary. */ 91 cpp_hashnode * 92 cpp_lookup (cpp_reader *pfile, const unsigned char *str, unsigned int len) 93 { 94 /* ht_lookup cannot return NULL. */ 95 return CPP_HASHNODE (ht_lookup (pfile->hash_table, str, len, HT_ALLOC)); 96 } 97 98 /* Determine whether the str STR, of length LEN, is a defined macro. */ 99 int 100 cpp_defined (cpp_reader *pfile, const unsigned char *str, int len) 101 { 102 cpp_hashnode *node; 103 104 node = CPP_HASHNODE (ht_lookup (pfile->hash_table, str, len, HT_NO_INSERT)); 105 106 /* If it's of type NT_MACRO, it cannot be poisoned. */ 107 return node && node->type == NT_MACRO; 108 } 109 110 /* We don't need a proxy since the hash table's identifier comes first 111 in cpp_hashnode. However, in case this is ever changed, we have a 112 static assertion for it. */ 113 extern char proxy_assertion_broken[offsetof (struct cpp_hashnode, ident) == 0 ? 1 : -1]; 114 115 /* For all nodes in the hashtable, callback CB with parameters PFILE, 116 the node, and V. */ 117 void 118 cpp_forall_identifiers (cpp_reader *pfile, cpp_cb cb, void *v) 119 { 120 ht_forall (pfile->hash_table, (ht_cb) cb, v); 121 } 122