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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: sym.h,v 1.9 1999/08/02 16:53:48 mdw Exp $ |
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4 | * |
5 | * Symbol table management |
6 | * |
7 | * (c) 1998 Straylight/Edgeware |
8 | */ |
9 | |
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10 | /*----- Licensing notice --------------------------------------------------* |
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11 | * |
12 | * This file is part of the mLib utilities library. |
13 | * |
14 | * mLib is free software; you can redistribute it and/or modify |
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15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
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19 | * mLib is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
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25 | * License along with mLib; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
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28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: sym.h,v $ |
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33 | * Revision 1.9 1999/08/02 16:53:48 mdw |
34 | * Improve type safety for sym_iter objects. |
35 | * |
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36 | * Revision 1.8 1999/08/02 14:45:48 mdw |
37 | * Break low-level hashtable code out from sym. |
38 | * |
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39 | * Revision 1.7 1999/06/01 09:49:33 mdw |
40 | * Allow things to be looked up by just their caller-supplied hashes. This |
41 | * actually needs to be thought through better. |
42 | * |
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43 | * Revision 1.6 1999/05/26 21:08:31 mdw |
44 | * Rename symbols in line with newer conventions. |
45 | * |
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46 | * Revision 1.5 1999/05/13 22:48:37 mdw |
47 | * Change `-ise' to `-ize' throughout. |
48 | * |
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49 | * Revision 1.4 1999/05/06 19:51:35 mdw |
50 | * Reformatted the LGPL notice a little bit. |
51 | * |
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52 | * Revision 1.3 1999/05/05 18:50:31 mdw |
53 | * Change licensing conditions to LGPL. |
54 | * |
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55 | * Revision 1.2 1998/11/26 19:27:34 mdw |
56 | * Move SYM_NAME into the header file. Fix bugs. |
57 | * |
58 | * Revision 1.1.1.1 1998/06/17 23:44:42 mdw |
59 | * Initial version of mLib |
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60 | * |
61 | */ |
62 | |
63 | #ifndef SYM_H |
64 | #define SYM_H |
65 | |
66 | #ifdef __cplusplus |
67 | extern "C" { |
68 | #endif |
69 | |
70 | /*----- Required headers --------------------------------------------------*/ |
71 | |
72 | #include <stddef.h> |
73 | |
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74 | #ifndef BITS_H |
75 | # include "bits.h" |
76 | #endif |
77 | |
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78 | #ifndef HASH_H |
79 | # include "hash.h" |
80 | #endif |
81 | |
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82 | /*----- Type definitions --------------------------------------------------*/ |
83 | |
84 | /* --- Symbol table --- * |
85 | * |
86 | * A @sym_table@ contains the information needed to manage a symbol table. |
87 | * Users shouldn't fiddle with this information directly, but it needs to be |
88 | * here so that objects of the correct type can be created. |
89 | */ |
90 | |
91 | typedef struct sym_table { |
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92 | hash_table t; |
93 | size_t load; |
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94 | } sym_table; |
95 | |
96 | /* --- A symbol table entry --- * |
97 | * |
98 | * I don't care what actually gets stored in symbol entries because I don't |
99 | * create them: that's the responsibility of my client. All I care about |
100 | * here is that whatever gets passed to me is a structure whose first member |
101 | * is a @sym_base@. The ANSI guarantees about structure layout are |
102 | * sufficient to allow me to manipulate such objects. |
103 | */ |
104 | |
105 | #define SYM_BUFSZ 16 /* Size of local string buffer */ |
106 | |
107 | typedef struct sym_base { |
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108 | hash_base b; |
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109 | union { |
110 | char *p; /* Pointer to name string */ |
111 | char b[SYM_BUFSZ]; /* Buffer containing a short name */ |
112 | } name; /* Name of this symbol */ |
113 | size_t len; /* Length of the symbol's name */ |
114 | } sym_base; |
115 | |
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116 | /* --- A macro to pick a symbol's name out from the mess --- */ |
117 | |
118 | #define SYM_NAME(sy) \ |
119 | (((sym_base *)(sy))->len > SYM_BUFSZ ? \ |
120 | ((sym_base *)(sy))->name.p : \ |
121 | ((sym_base *)(sy))->name.b) |
122 | |
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123 | /* --- An iterator block --- */ |
124 | |
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125 | typedef struct { hash_iter i; } sym_iter; |
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126 | |
127 | /*----- External functions ------------------------------------------------*/ |
128 | |
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129 | /* --- @sym_create@ --- * |
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130 | * |
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131 | * Arguments: @sym_table *t@ = symbol table to initialize |
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132 | * |
133 | * Returns: --- |
134 | * |
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135 | * Use: Initializes the given symbol table. Raises @EXC_NOMEM@ if |
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136 | * there isn't enough memory. |
137 | */ |
138 | |
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139 | extern void sym_create(sym_table */*t*/); |
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140 | |
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141 | /* --- @sym_destroy@ --- * |
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142 | * |
143 | * Arguments: @sym_table *t@ = pointer to symbol table in question |
144 | * |
145 | * Returns: --- |
146 | * |
147 | * Use: Destroys a symbol table, freeing all the memory it used to |
148 | * occupy. |
149 | */ |
150 | |
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151 | extern void sym_destroy(sym_table */*t*/); |
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152 | |
153 | /* --- @sym_find@ --- * |
154 | * |
155 | * Arguments: @sym_table *t@ = pointer to symbol table in question |
156 | * @const char *n@ = pointer to symbol table to look up |
157 | * @long l@ = length of the name string or negative to measure |
158 | * @size_t sz@ = size of desired symbol object, or zero |
159 | * @unsigned *f@ = pointer to a flag, or null. |
160 | * |
161 | * Returns: The address of a @sym_base@ structure, or null if not found |
162 | * and @sz@ is zero. |
163 | * |
164 | * Use: Looks up a symbol in a given symbol table. The name is |
165 | * passed by the address of its first character. The length |
166 | * may be given, in which case the name may contain arbitrary |
167 | * binary data, or it may be given as a negative number, in |
168 | * which case the length of the name is calculated as |
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169 | * @strlen(n) + 1@. |
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170 | * |
171 | * The return value is the address of a pointer to a @sym_base@ |
172 | * block (which may have other things on the end, as above). If |
173 | * the symbol could be found, the return value points to the |
174 | * symbol block. If the symbol wasn't there, then if @sz@ is |
175 | * nonzero, a new symbol is created and its address is returned; |
176 | * otherwise a null pointer is returned. The exception |
177 | * @EXC_NOMEM@ is raised if the block can't be allocated. |
178 | * |
179 | * The value of @*f@ indicates whether a new symbol entry was |
180 | * created: a nonzero value indicates that an old value was |
181 | * found. |
182 | */ |
183 | |
184 | extern void *sym_find(sym_table */*t*/, const char */*n*/, long /*l*/, |
185 | size_t /*sz*/, unsigned */*f*/); |
186 | |
187 | /* --- @sym_remove@ --- * |
188 | * |
189 | * Arguments: @sym_table *i@ = pointer to a symbol table object |
190 | * @void *b@ = pointer to symbol table entry |
191 | * |
192 | * Returns: --- |
193 | * |
194 | * Use: Removes the object from the symbol table. The space occupied |
195 | * by the object and its name is freed; anything else attached |
196 | * to the entry should already be gone by this point. |
197 | */ |
198 | |
199 | extern void sym_remove(sym_table */*t*/, void */*b*/); |
200 | |
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201 | /* --- @sym_mkiter@ --- * |
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202 | * |
203 | * Arguments: @sym_iter *i@ = pointer to an iterator object |
204 | * @sym_table *t@ = pointer to a symbol table object |
205 | * |
206 | * Returns: --- |
207 | * |
208 | * Use: Creates a new symbol table iterator which may be used to |
209 | * iterate through a symbol table. |
210 | */ |
211 | |
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212 | #define SYM_MKITER(i_, t_) HASH_MKITER(&(i_)->i, &(t_)->t) |
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213 | |
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214 | extern void sym_mkiter(sym_iter */*i*/, sym_table */*t*/); |
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215 | |
216 | /* --- @sym_next@ --- * |
217 | * |
218 | * Arguments: @sym_iter *i@ = pointer to iterator object |
219 | * |
220 | * Returns: Pointer to the next symbol found, or null when finished. |
221 | * |
222 | * Use: Returns the next symbol from the table. Symbols are not |
223 | * returned in any particular order. |
224 | */ |
225 | |
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226 | #define SYM_NEXT(i_, p) do { \ |
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227 | hash_base *_q; \ |
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228 | HASH_NEXT(&(i_)->i, _q); \ |
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229 | (p) = (void *)_q; \ |
230 | } while (0) |
231 | |
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232 | extern void *sym_next(sym_iter */*i*/); |
233 | |
234 | /*----- That's all, folks -------------------------------------------------*/ |
235 | |
236 | #ifdef __cplusplus |
237 | } |
238 | #endif |
239 | |
240 | #endif |