| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id$ |
| 4 | * |
| 5 | * Symbol table management |
| 6 | * |
| 7 | * (c) 1998 Straylight |
| 8 | * (c) 2000 Mark Wooding |
| 9 | */ |
| 10 | |
| 11 | /*----- Licensing notice --------------------------------------------------* |
| 12 | * |
| 13 | * Copyright (c) 2000 Mark Wooding |
| 14 | * All rights reserved. |
| 15 | * |
| 16 | * Redistribution and use in source and binary forms, with or without |
| 17 | * modification, are permitted provided that the following conditions are |
| 18 | * met: |
| 19 | * |
| 20 | * 1. Redistributions of source code must retain the above copyright |
| 21 | * notice, this list of conditions and the following disclaimer. |
| 22 | * |
| 23 | * 2, Redistributions in binary form must reproduce the above copyright |
| 24 | * notice, this list of conditions and the following disclaimer in the |
| 25 | * documentation and/or other materials provided with the distribution. |
| 26 | * |
| 27 | * 3. The name of the authors may not be used to endorse or promote |
| 28 | * products derived from this software without specific prior written |
| 29 | * permission. |
| 30 | * |
| 31 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| 32 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 33 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN |
| 34 | * NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, |
| 35 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 36 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| 37 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 38 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 39 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
| 40 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 41 | * POSSIBILITY OF SUCH DAMAGE. |
| 42 | * |
| 43 | * Instead of accepting the above terms, you may redistribute and/or modify |
| 44 | * this software under the terms of either the GNU General Public License, |
| 45 | * or the GNU Library General Public License, published by the Free |
| 46 | * Software Foundation; either version 2 of the License, or (at your |
| 47 | * option) any later version. |
| 48 | */ |
| 49 | |
| 50 | /*----- Revision history --------------------------------------------------* |
| 51 | * |
| 52 | * $Log: sym.h,v $ |
| 53 | * Revision 1.2 2000/07/02 15:21:20 mdw |
| 54 | * Fix licence text. |
| 55 | * |
| 56 | * Revision 1.1 2000/05/21 11:28:30 mdw |
| 57 | * Initial check-in. |
| 58 | * |
| 59 | * --- Past lives (Become) --- * |
| 60 | * |
| 61 | * Revision 1.3 1998/01/12 16:46:30 mdw |
| 62 | * Fix copyright date. |
| 63 | * |
| 64 | * Revision 1.2 1997/08/04 10:24:25 mdw |
| 65 | * Sources placed under CVS control. |
| 66 | * |
| 67 | * Revision 1.1 1997/07/21 13:47:43 mdw |
| 68 | * Initial revision |
| 69 | * |
| 70 | */ |
| 71 | |
| 72 | #ifndef SYM_H |
| 73 | #define SYM_H |
| 74 | |
| 75 | #ifdef __cplusplus |
| 76 | extern "C" { |
| 77 | #endif |
| 78 | |
| 79 | /*----- Required headers --------------------------------------------------*/ |
| 80 | |
| 81 | #include <stddef.h> |
| 82 | |
| 83 | #ifndef BITS_H |
| 84 | # include "bits.h" |
| 85 | #endif |
| 86 | |
| 87 | /*----- Type definitions --------------------------------------------------*/ |
| 88 | |
| 89 | /* --- Symbol table --- * |
| 90 | * |
| 91 | * A @sym_table@ contains the information needed to manage a symbol table. |
| 92 | * Users shouldn't fiddle with this information directly, but it needs to be |
| 93 | * here so that objects of the correct type can be created. |
| 94 | */ |
| 95 | |
| 96 | typedef struct sym_table { |
| 97 | uint32 mask; /* Bit mask for hashing purposes */ |
| 98 | size_t c; /* Down counter for growing table */ |
| 99 | struct sym_base **a; /* Array of hash bins */ |
| 100 | } sym_table; |
| 101 | |
| 102 | /* --- A symbol table entry --- * |
| 103 | * |
| 104 | * I don't care what actually gets stored in symbol entries because I don't |
| 105 | * create them: that's the responsibility of my client. All I care about |
| 106 | * here is that whatever gets passed to me is a structure whose first member |
| 107 | * is a @sym_base@. The ANSI guarantees about structure layout are |
| 108 | * sufficient to allow me to manipulate such objects. |
| 109 | */ |
| 110 | |
| 111 | typedef struct sym_base { |
| 112 | struct sym_base *next; /* Next symbol in hash bin */ |
| 113 | uint32 hash; /* Hash value for symbol's name */ |
| 114 | char *name; /* Name of this symbol */ |
| 115 | size_t len; /* Length of the symbol's name */ |
| 116 | } sym_base; |
| 117 | |
| 118 | /* --- An iterator block --- */ |
| 119 | |
| 120 | typedef struct sym_iter { |
| 121 | sym_table *t; /* Symbol table being iterated */ |
| 122 | sym_base *n; /* Address of next item to return */ |
| 123 | size_t i; /* Index of next hash bin to use */ |
| 124 | } sym_iter; |
| 125 | |
| 126 | /*----- External functions ------------------------------------------------*/ |
| 127 | |
| 128 | /* --- @sym_create@ --- * |
| 129 | * |
| 130 | * Arguments: @sym_table *t@ = symbol table to initialize |
| 131 | * |
| 132 | * Returns: --- |
| 133 | * |
| 134 | * Use: Initialises the given symbol table. |
| 135 | */ |
| 136 | |
| 137 | extern void sym_create(sym_table */*t*/); |
| 138 | |
| 139 | /* --- @sym_destroy@ --- * |
| 140 | * |
| 141 | * Arguments: @sym_table *t@ = pointer to symbol table in question |
| 142 | * |
| 143 | * Returns: --- |
| 144 | * |
| 145 | * Use: Destroys a symbol table, freeing all the memory it used to |
| 146 | * occupy. |
| 147 | */ |
| 148 | |
| 149 | extern void sym_destroy(sym_table */*t*/); |
| 150 | |
| 151 | /* --- @sym_find@ --- * |
| 152 | * |
| 153 | * Arguments: @sym_table *t@ = pointer to symbol table in question |
| 154 | * @const char *n@ = pointer to symbol table to look up |
| 155 | * @long l@ = length of the name string or negative to measure |
| 156 | * @size_t sz@ = size of desired symbol object, or zero |
| 157 | * @unsigned *f@ = pointer to a flag, or null. |
| 158 | * |
| 159 | * Returns: The address of a @sym_base@ structure, or null if not found |
| 160 | * and @sz@ is zero. |
| 161 | * |
| 162 | * Use: Looks up a symbol in a given symbol table. The name is |
| 163 | * passed by the address of its first character. The length |
| 164 | * may be given, in which case the name may contain arbitrary |
| 165 | * binary data, or it may be given as a negative number, in |
| 166 | * which case the length of the name is calculated as |
| 167 | * @strlen(n)@. |
| 168 | * |
| 169 | * The return value is the address of a pointer to a @sym_base@ |
| 170 | * block (which may have other things on the end, as above). If |
| 171 | * the symbol could be found, the return value points to the |
| 172 | * symbol block. If the symbol wasn't there, then if @sz@ is |
| 173 | * nonzero, a new symbol is created and its address is returned; |
| 174 | * otherwise a null pointer is returned. |
| 175 | * |
| 176 | * The value of @*f@ indicates whether a new symbol entry was |
| 177 | * created: a nonzero value indicates that an old value was |
| 178 | * found. |
| 179 | */ |
| 180 | |
| 181 | extern void *sym_find(sym_table */*t*/, const char */*n*/, long /*l*/, |
| 182 | size_t /*sz*/, unsigned */*f*/); |
| 183 | |
| 184 | /* --- @sym_remove@ --- * |
| 185 | * |
| 186 | * Arguments: @sym_table *i@ = pointer to a symbol table object |
| 187 | * @void *b@ = pointer to symbol table entry |
| 188 | * |
| 189 | * Returns: --- |
| 190 | * |
| 191 | * Use: Removes the object from the symbol table. The space occupied |
| 192 | * by the object and its name is freed; anything else attached |
| 193 | * to the entry should already be gone by this point. |
| 194 | */ |
| 195 | |
| 196 | extern void sym_remove(sym_table */*t*/, void */*b*/); |
| 197 | |
| 198 | /* --- @sym_mkiter@ --- * |
| 199 | * |
| 200 | * Arguments: @sym_iter *i@ = pointer to an iterator object |
| 201 | * @sym_table *t@ = pointer to a symbol table object |
| 202 | * |
| 203 | * Returns: --- |
| 204 | * |
| 205 | * Use: Creates a new symbol table iterator which may be used to |
| 206 | * iterate through a symbol table. |
| 207 | */ |
| 208 | |
| 209 | extern void sym_mkiter(sym_iter */*i*/, sym_table */*t*/); |
| 210 | |
| 211 | /* --- @sym_next@ --- * |
| 212 | * |
| 213 | * Arguments: @sym_iter *i@ = pointer to iterator object |
| 214 | * |
| 215 | * Returns: Pointer to the next symbol found, or null when finished. |
| 216 | * |
| 217 | * Use: Returns the next symbol from the table. Symbols are not |
| 218 | * returned in any particular order. |
| 219 | */ |
| 220 | |
| 221 | extern void *sym_next(sym_iter */*i*/); |
| 222 | |
| 223 | /*----- That's all, folks -------------------------------------------------*/ |
| 224 | |
| 225 | #ifdef __cplusplus |
| 226 | } |
| 227 | #endif |
| 228 | |
| 229 | #endif |