1 /* Hash tables for the CPP library. 2 Copyright (C) 1986-2013 Free Software Foundation, Inc. 3 Written by Per Bothner, 1994. 4 Based on CCCP program by Paul Rubin, June 1986 5 Adapted to ANSI C, Richard Stallman, Jan 1987 6 7 This program is free software; you can redistribute it and/or modify it 8 under the terms of the GNU General Public License as published by the 9 Free Software Foundation; either version 3, or (at your option) any 10 later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. 20 21 In other words, you are welcome to use, share and improve this program. 22 You are forbidden to forbid anyone else to use, share and improve 23 what you give them. Help stamp out software-hoarding! */ 24 25 #include "config.h" 26 #include "system.h" 27 #include "cpplib.h" 28 #include "internal.h" 29 30 static hashnode alloc_node (cpp_hash_table *); 31 32 /* Return an identifier node for hashtable.c. Used by cpplib except 33 when integrated with the C front ends. */ 34 static hashnode 35 alloc_node (cpp_hash_table *table) 36 { 37 cpp_hashnode *node; 38 39 node = XOBNEW (&table->pfile->hash_ob, cpp_hashnode); 40 memset (node, 0, sizeof (cpp_hashnode)); 41 return HT_NODE (node); 42 } 43 44 /* Set up the identifier hash table. Use TABLE if non-null, otherwise 45 create our own. */ 46 void 47 _cpp_init_hashtable (cpp_reader *pfile, cpp_hash_table *table) 48 { 49 struct spec_nodes *s; 50 51 if (table == NULL) 52 { 53 pfile->our_hashtable = 1; 54 table = ht_create (13); /* 8K (=2^13) entries. */ 55 table->alloc_node = alloc_node; 56 57 _obstack_begin (&pfile->hash_ob, 0, 0, 58 (void *(*) (long)) xmalloc, 59 (void (*) (void *)) free); 60 } 61 62 table->pfile = pfile; 63 pfile->hash_table = table; 64 65 /* Now we can initialize things that use the hash table. */ 66 _cpp_init_directives (pfile); 67 _cpp_init_internal_pragmas (pfile); 68 69 s = &pfile->spec_nodes; 70 s->n_defined = cpp_lookup (pfile, DSC("defined")); 71 s->n_true = cpp_lookup (pfile, DSC("true")); 72 s->n_false = cpp_lookup (pfile, DSC("false")); 73 s->n__VA_ARGS__ = cpp_lookup (pfile, DSC("__VA_ARGS__")); 74 s->n__VA_ARGS__->flags |= NODE_DIAGNOSTIC; 75 } 76 77 /* Tear down the identifier hash table. */ 78 void 79 _cpp_destroy_hashtable (cpp_reader *pfile) 80 { 81 if (pfile->our_hashtable) 82 { 83 ht_destroy (pfile->hash_table); 84 obstack_free (&pfile->hash_ob, 0); 85 } 86 } 87 88 /* Returns the hash entry for the STR of length LEN, creating one 89 if necessary. */ 90 cpp_hashnode * 91 cpp_lookup (cpp_reader *pfile, const unsigned char *str, unsigned int len) 92 { 93 /* ht_lookup cannot return NULL. */ 94 return CPP_HASHNODE (ht_lookup (pfile->hash_table, str, len, HT_ALLOC)); 95 } 96 97 /* Determine whether the str STR, of length LEN, is a defined macro. */ 98 int 99 cpp_defined (cpp_reader *pfile, const unsigned char *str, int len) 100 { 101 cpp_hashnode *node; 102 103 node = CPP_HASHNODE (ht_lookup (pfile->hash_table, str, len, HT_NO_INSERT)); 104 105 /* If it's of type NT_MACRO, it cannot be poisoned. */ 106 return node && node->type == NT_MACRO; 107 } 108 109 /* We don't need a proxy since the hash table's identifier comes first 110 in cpp_hashnode. However, in case this is ever changed, we have a 111 static assertion for it. */ 112 extern char proxy_assertion_broken[offsetof (struct cpp_hashnode, ident) == 0 ? 1 : -1]; 113 114 /* For all nodes in the hashtable, callback CB with parameters PFILE, 115 the node, and V. */ 116 void 117 cpp_forall_identifiers (cpp_reader *pfile, cpp_cb cb, void *v) 118 { 119 ht_forall (pfile->hash_table, (ht_cb) cb, v); 120 } 121