1 /* Hash tables. 2 Copyright (C) 2000, 2001, 2003, 2004, 2007, 2008, 2009, 2010 3 Free Software Foundation, Inc. 4 5 This program is free software; you can redistribute it and/or modify it 6 under the terms of the GNU General Public License as published by the 7 Free Software Foundation; either version 3, or (at your option) any 8 later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program; see the file COPYING3. If not see 17 <http://www.gnu.org/licenses/>. */ 18 19 #ifndef LIBCPP_SYMTAB_H 20 #define LIBCPP_SYMTAB_H 21 22 #include "obstack.h" 23 24 #ifndef GTY 25 #define GTY(x) /* nothing */ 26 #endif 27 28 /* This is what each hash table entry points to. It may be embedded 29 deeply within another object. */ 30 typedef struct ht_identifier ht_identifier; 31 typedef struct ht_identifier *ht_identifier_ptr; 32 struct GTY(()) ht_identifier { 33 const unsigned char *str; 34 unsigned int len; 35 unsigned int hash_value; 36 }; 37 38 #define HT_LEN(NODE) ((NODE)->len) 39 #define HT_STR(NODE) ((NODE)->str) 40 41 typedef struct ht hash_table; 42 typedef struct ht_identifier *hashnode; 43 44 enum ht_lookup_option {HT_NO_INSERT = 0, HT_ALLOC}; 45 46 /* An identifier hash table for cpplib and the front ends. */ 47 struct ht 48 { 49 /* Identifiers are allocated from here. */ 50 struct obstack stack; 51 52 hashnode *entries; 53 /* Call back, allocate a node. */ 54 hashnode (*alloc_node) (hash_table *); 55 /* Call back, allocate something that hangs off a node like a cpp_macro. 56 NULL means use the usual allocator. */ 57 void * (*alloc_subobject) (size_t); 58 59 unsigned int nslots; /* Total slots in the entries array. */ 60 unsigned int nelements; /* Number of live elements. */ 61 62 /* Link to reader, if any. For the benefit of cpplib. */ 63 struct cpp_reader *pfile; 64 65 /* Table usage statistics. */ 66 unsigned int searches; 67 unsigned int collisions; 68 69 /* Should 'entries' be freed when it is no longer needed? */ 70 bool entries_owned; 71 }; 72 73 /* Initialize the hashtable with 2 ^ order entries. */ 74 extern hash_table *ht_create (unsigned int order); 75 76 /* Frees all memory associated with a hash table. */ 77 extern void ht_destroy (hash_table *); 78 79 extern hashnode ht_lookup (hash_table *, const unsigned char *, 80 size_t, enum ht_lookup_option); 81 extern hashnode ht_lookup_with_hash (hash_table *, const unsigned char *, 82 size_t, unsigned int, 83 enum ht_lookup_option); 84 #define HT_HASHSTEP(r, c) ((r) * 67 + ((c) - 113)); 85 #define HT_HASHFINISH(r, len) ((r) + (len)) 86 87 /* For all nodes in TABLE, make a callback. The callback takes 88 TABLE->PFILE, the node, and a PTR, and the callback sequence stops 89 if the callback returns zero. */ 90 typedef int (*ht_cb) (struct cpp_reader *, hashnode, const void *); 91 extern void ht_forall (hash_table *, ht_cb, const void *); 92 93 /* For all nodes in TABLE, call the callback. If the callback returns 94 a nonzero value, the node is removed from the table. */ 95 extern void ht_purge (hash_table *, ht_cb, const void *); 96 97 /* Restore the hash table. */ 98 extern void ht_load (hash_table *ht, hashnode *entries, 99 unsigned int nslots, unsigned int nelements, bool own); 100 101 /* Dump allocation statistics to stderr. */ 102 extern void ht_dump_statistics (hash_table *); 103 104 #endif /* LIBCPP_SYMTAB_H */ 105
