1 /*===========================================================================
2 Copyright (c) 1998-2000, The Santa Cruz Operation
3 All rights reserved.
4
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions are met:
7
8 *Redistributions of source code must retain the above copyright notice,
9 this list of conditions and the following disclaimer.
10
11 *Redistributions in binary form must reproduce the above copyright notice,
12 this list of conditions and the following disclaimer in the documentation
13 and/or other materials provided with the distribution.
14
15 *Neither name of The Santa Cruz Operation nor the names of its contributors
16 may be used to endorse or promote products derived from this software
17 without specific prior written permission.
18
19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
20 IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
23 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 INTERRUPTION)
27 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
30 DAMAGE.
31 =========================================================================*/
32
33 /* cscope - interactive C symbol cross-reference
34 *
35 * keyword look-up routine for the C symbol scanner
36 */
37
38 #include "global.h"
39 #include "lookup.h"
40
41 /* keyword text for fast testing of keywords in the scanner */
42 char enumtext[] = "enum";
43 char externtext[] = "extern";
44 char structtext[] = "struct";
45 char typedeftext[] = "typedef";
46 char uniontext[] = "union";
47
48 /* This keyword table is also used for keyword text compression. Keywords
49 * with an index less than the numeric value of a space are replaced with the
50 * control character corresponding to the index, so they cannot be moved
51 * without changing the database file version and adding compatibility code
52 * for old databases.
53 */
54 struct keystruct keyword[] = {
55 {"", '\0', NULL}, /* dummy entry */
56 {"#define", ' ', NULL}, /* must be table entry 1 */
57 {"#include", ' ', NULL}, /* must be table entry 2 */
58 {"break", '\0', NULL}, /* rarely in cross-reference */
59 {"case", ' ', NULL},
60 {"char", ' ', NULL},
61 {"continue", '\0', NULL}, /* rarely in cross-reference */
62 {"default", '\0', NULL}, /* rarely in cross-reference */
63 {"double", ' ', NULL},
64 {"\t", '\0', NULL}, /* must be the table entry 9 */
65 {"\n", '\0', NULL}, /* must be the table entry 10 */
66 {"else", ' ', NULL},
67 {enumtext, ' ', NULL},
68 {externtext, ' ', NULL},
69 {"float", ' ', NULL},
70 {"for", '(', NULL},
71 {"goto", ' ', NULL},
72 {"if", '(', NULL},
73 {"int", ' ', NULL},
74 {"long", ' ', NULL},
75 {"register", ' ', NULL},
76 {"return", '\0', NULL},
77 {"short", ' ', NULL},
78 {"sizeof", '\0', NULL},
79 {"static", ' ', NULL},
80 {structtext, ' ', NULL},
81 {"switch", '(', NULL},
82 {typedeftext, ' ', NULL},
83 {uniontext, ' ', NULL},
84 {"unsigned", ' ', NULL},
85 {"void", ' ', NULL},
86 {"while", '(', NULL},
87
88 /* these keywords are not compressed */
89 {"do", '\0', NULL},
90 {"auto", ' ', NULL},
91 {"fortran", ' ', NULL},
92 {"const", ' ', NULL},
93 {"signed", ' ', NULL},
94 {"volatile", ' ', NULL},
95 };
96 #define KEYWORDS (sizeof(keyword) / sizeof(keyword[0]))
97
98 #define HASHMOD (KEYWORDS * 2 + 1)
99
100 static struct keystruct *hashtab[HASHMOD]; /* pointer table */
101
102 /* put the keywords into the symbol table */
103
104 void
initsymtab(void)105 initsymtab(void)
106 {
107 unsigned int i, j;
108 struct keystruct *p;
109
110 for (i = 1; i < KEYWORDS; ++i) {
111 p = keyword + i;
112 j = hash(p->text) % HASHMOD;
113 p->next = hashtab[j];
114 hashtab[j] = p;
115 }
116 }
117
118 /* see if this identifier is a keyword */
119
120 char *
lookup(char * ident)121 lookup(char *ident)
122 {
123 struct keystruct *p;
124 int c;
125
126 /* look up the identifier in the keyword table */
127 for (p = hashtab[hash(ident) % HASHMOD]; p != NULL; p = p->next) {
128 if (strequal(ident, p->text)) {
129 if (compress == YES && (c = p - keyword) < ' ') {
130 ident[0] = c; /* compress the keyword */
131 }
132 return(p->text);
133 }
134 }
135 /* this is an identifier */
136 return(NULL);
137 }
138
139 /* form hash value for string */
140 int
hash(char * ss)141 hash(char *ss)
142 {
143 int i;
144 unsigned char *s = (unsigned char *)ss;
145
146 for (i = 0; *s != '\0'; )
147 i += *s++; /* += is faster than <<= for cscope */
148 return(i);
149 }
150