1 /* Hash tables. 2 Copyright (C) 2000-2021 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 3, 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; see the file COPYING3. If not see 16 <http://www.gnu.org/licenses/>. */ 17 18 #ifndef LIBCPP_SYMTAB_H 19 #define LIBCPP_SYMTAB_H 20 21 #include "obstack.h" 22 23 #ifndef GTY 24 #define GTY(x) /* nothing */ 25 #endif 26 27 /* This is what each hash table entry points to. It may be embedded 28 deeply within another object. */ 29 typedef struct ht_identifier ht_identifier; 30 typedef struct ht_identifier *ht_identifier_ptr; 31 struct GTY(()) ht_identifier { 32 const unsigned char *str; 33 unsigned int len; 34 unsigned int hash_value; 35 }; 36 37 #define HT_LEN(NODE) ((NODE)->len) 38 #define HT_STR(NODE) ((NODE)->str) 39 40 typedef struct ht cpp_hash_table; 41 typedef struct ht_identifier *hashnode; 42 43 enum ht_lookup_option {HT_NO_INSERT = 0, HT_ALLOC}; 44 45 /* An identifier hash table for cpplib and the front ends. */ 46 struct ht 47 { 48 /* Identifiers are allocated from here. */ 49 struct obstack stack; 50 51 hashnode *entries; 52 /* Call back, allocate a node. */ 53 hashnode (*alloc_node) (cpp_hash_table *); 54 /* Call back, allocate something that hangs off a node like a cpp_macro. 55 NULL means use the usual allocator. */ 56 void * (*alloc_subobject) (size_t); 57 58 unsigned int nslots; /* Total slots in the entries array. */ 59 unsigned int nelements; /* Number of live elements. */ 60 61 /* Link to reader, if any. For the benefit of cpplib. */ 62 struct cpp_reader *pfile; 63 64 /* Table usage statistics. */ 65 unsigned int searches; 66 unsigned int collisions; 67 68 /* Should 'entries' be freed when it is no longer needed? */ 69 bool entries_owned; 70 }; 71 72 /* Initialize the hashtable with 2 ^ order entries. */ 73 extern cpp_hash_table *ht_create (unsigned int order); 74 75 /* Frees all memory associated with a hash table. */ 76 extern void ht_destroy (cpp_hash_table *); 77 78 extern hashnode ht_lookup (cpp_hash_table *, const unsigned char *, 79 size_t, enum ht_lookup_option); 80 extern hashnode ht_lookup_with_hash (cpp_hash_table *, const unsigned char *, 81 size_t, unsigned int, 82 enum ht_lookup_option); 83 #define HT_HASHSTEP(r, c) ((r) * 67 + ((c) - 113)); 84 #define HT_HASHFINISH(r, len) ((r) + (len)) 85 86 /* For all nodes in TABLE, make a callback. The callback takes 87 TABLE->PFILE, the node, and a PTR, and the callback sequence stops 88 if the callback returns zero. */ 89 typedef int (*ht_cb) (struct cpp_reader *, hashnode, const void *); 90 extern void ht_forall (cpp_hash_table *, ht_cb, const void *); 91 92 /* For all nodes in TABLE, call the callback. If the callback returns 93 a nonzero value, the node is removed from the table. */ 94 extern void ht_purge (cpp_hash_table *, ht_cb, const void *); 95 96 /* Restore the hash table. */ 97 extern void ht_load (cpp_hash_table *ht, hashnode *entries, 98 unsigned int nslots, unsigned int nelements, bool own); 99 100 /* Dump allocation statistics to stderr. */ 101 extern void ht_dump_statistics (cpp_hash_table *); 102 103 #endif /* LIBCPP_SYMTAB_H */ 104