xref: /titanic_41/usr/src/tools/cscope-fast/lookup.c (revision fcf3ce441efd61da9bb2884968af01cb7c1452cc)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*	Copyright (c) 1988 AT&T	*/
23 /*	  All Rights Reserved  	*/
24 
25 
26 /*
27  * Copyright (c) 1999 by Sun Microsystems, Inc.
28  * All rights reserved.
29  */
30 
31 #pragma ident	"%Z%%M%	%I%	%E% SMI"
32 
33 /*
34  *	cscope - interactive C symbol cross-reference
35  *
36  *	keyword look-up routine for the C symbol scanner
37  */
38 
39 #include "global.h"
40 
41 /* keyword text for fast testing of keywords in the scanner */
42 char	externtext[] = "extern";
43 char	typedeftext[] = "typedef";
44 
45 /*
46  * This keyword table is also used for keyword text compression.  Keywords
47  * with an index less than the numeric value of a space are replaced with the
48  * control character corresponding to the index, so they cannot be moved
49  * without changing the database file version and adding compatibility code
50  * for old databases.
51  */
52 struct	keystruct keyword[] = {
53 	{ "#define",	' ',	MISC,	NULL },	/* must be table entry 0 */
54 						/* for old databases */
55 	{ "#include",	' ',	MISC,	NULL },	/* must be table entry 1 */
56 	{ "break",	'\0',	FLOW,	NULL },	/* rarely in cross-reference */
57 	{ "case",	' ',	FLOW,	NULL },
58 	{ "char",	' ',	DECL,	NULL },
59 	{ "continue",	'\0',	FLOW,	NULL },	/* rarely in cross-reference */
60 	{ "default",	'\0',	FLOW,	NULL },	/* rarely in cross-reference */
61 	{ "#define",	' ',	MISC,	NULL },	/* must be table entry 7 */
62 	{ "double",	' ',	DECL,	NULL },
63 	{ "\t",		'\0',	MISC,	NULL },	/* must be table entry 9 */
64 	{ "\n",		'\0',	MISC,	NULL },	/* must be table entry 10 */
65 	{ "else",	' ',	FLOW,	NULL },
66 	{ "enum",	' ',	DECL,	NULL },
67 	{ externtext,	' ',	DECL,	NULL },
68 	{ "float",	' ',	DECL,	NULL },
69 	{ "for",	'(',	FLOW,	NULL },
70 	{ "goto",	' ',	FLOW,	NULL },
71 	{ "if",		'(',	FLOW,	NULL },
72 	{ "int",	' ',	DECL,	NULL },
73 	{ "long",	' ',	DECL,	NULL },
74 	{ "register",	' ',	DECL,	NULL },
75 	{ "return",	'\0',	FLOW,	NULL },
76 	{ "short",	' ',	DECL,	NULL },
77 	{ "sizeof",	'\0',	MISC,	NULL },
78 	{ "static",	' ',	DECL,	NULL },
79 	{ "struct",	' ',	DECL,	NULL },
80 	{ "switch",	'(',	FLOW,	NULL },
81 	{ typedeftext,	' ',	DECL,	NULL },
82 	{ "union",	' ',	DECL,	NULL },
83 	{ "unsigned",	' ',	DECL,	NULL },
84 	{ "void",	' ',	DECL,	NULL },
85 	{ "while",	'(',	FLOW,	NULL },
86 
87 	/* these keywords are not compressed */
88 	{ "auto",	' ',	DECL,	NULL },
89 	{ "do",		' ',	FLOW,	NULL },
90 	{ "fortran",	' ',	DECL,	NULL },
91 	{ "const",	' ',	DECL,	NULL },
92 	{ "signed",	' ',	DECL,	NULL },
93 	{ "volatile",	' ',	DECL,	NULL },
94 };
95 
96 #define	KEYWORDS	(sizeof (keyword) / sizeof (struct keystruct))
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
105 initsymtab(void)
106 {
107 	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 struct keystruct *
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);
133 		}
134 	}
135 	/* this is an identifier */
136 	return (NULL);
137 }
138 
139 /* form hash value for string */
140 
141 int
142 hash(char *s)
143 {
144 	unsigned i;
145 
146 	for (i = 0; *s != '\0'; )
147 		i += *s++;	/* += is faster than <<= for cscope */
148 	return (i);
149 }
150