aboutsummaryrefslogtreecommitdiffstats
path: root/amend/symtab.c
blob: 835d2fc4092770f3f5f8ed18388591af5e07456a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stdlib.h>
#include <string.h>
#include "symtab.h"

#define DEFAULT_TABLE_SIZE 16

typedef struct {
    char *symbol;
    const void *cookie;
    unsigned int flags;
} SymbolTableEntry;

struct SymbolTable {
    SymbolTableEntry *table;
    int numEntries;
    int maxSize;
};

SymbolTable *
createSymbolTable()
{
    SymbolTable *tab;

    tab = (SymbolTable *)malloc(sizeof(SymbolTable));
    if (tab != NULL) {
        tab->numEntries = 0;
        tab->maxSize = DEFAULT_TABLE_SIZE;
        tab->table = (SymbolTableEntry *)malloc(
                            tab->maxSize * sizeof(SymbolTableEntry));
        if (tab->table == NULL) {
            free(tab);
            tab = NULL;
        }
    }
    return tab;
}

void
deleteSymbolTable(SymbolTable *tab)
{
    if (tab != NULL) {
        while (tab->numEntries > 0) {
            free(tab->table[--tab->numEntries].symbol);
        }
        free(tab->table);
    }
}

void *
findInSymbolTable(SymbolTable *tab, const char *symbol, unsigned int flags)
{
    int i;

    if (tab == NULL || symbol == NULL) {
        return NULL;
    }

    // TODO: Sort the table and binary search
    for (i = 0; i < tab->numEntries; i++) {
        if (strcmp(tab->table[i].symbol, symbol) == 0 &&
                tab->table[i].flags == flags)
        {
            return (void *)tab->table[i].cookie;
        }
    }

    return NULL;
}

int
addToSymbolTable(SymbolTable *tab, const char *symbol, unsigned int flags,
        const void *cookie)
{
    if (tab == NULL || symbol == NULL || cookie == NULL) {
        return -1;
    }

    /* Make sure that this symbol isn't already in the table.
     */
    if (findInSymbolTable(tab, symbol, flags) != NULL) {
        return -2;
    }

    /* Make sure there's enough space for the new entry.
     */
    if (tab->numEntries == tab->maxSize) {
        SymbolTableEntry *newTable;
        int newSize;

        newSize = tab->numEntries * 2;
        if (newSize < DEFAULT_TABLE_SIZE) {
            newSize = DEFAULT_TABLE_SIZE;
        }
        newTable = (SymbolTableEntry *)realloc(tab->table,
                            newSize * sizeof(SymbolTableEntry));
        if (newTable == NULL) {
            return -1;
        }
        tab->maxSize = newSize;
        tab->table = newTable;
    }

    /* Insert the new entry.
     */
    symbol = strdup(symbol);
    if (symbol == NULL) {
        return -1;
    }
    // TODO: Sort the table
    tab->table[tab->numEntries].symbol = (char *)symbol;
    tab->table[tab->numEntries].cookie = cookie;
    tab->table[tab->numEntries].flags = flags;
    tab->numEntries++;

    return 0;
}