xref: /illumos-gate/usr/src/tools/cscope-fast/lookup.c (revision 8aafd47d0dbabbca4365c9565fbe0e051e7346dd)
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 /*
32  *	cscope - interactive C symbol cross-reference
33  *
34  *	keyword look-up routine for the C symbol scanner
35  */
36 
37 #include "global.h"
38 
39 /* keyword text for fast testing of keywords in the scanner */
40 char	externtext[] = "extern";
41 char	typedeftext[] = "typedef";
42 
43 /*
44  * This keyword table is also used for keyword text compression.  Keywords
45  * with an index less than the numeric value of a space are replaced with the
46  * control character corresponding to the index, so they cannot be moved
47  * without changing the database file version and adding compatibility code
48  * for old databases.
49  */
50 struct	keystruct keyword[] = {
51 	{ "#define",	' ',	MISC,	NULL },	/* must be table entry 0 */
52 						/* for old databases */
53 	{ "#include",	' ',	MISC,	NULL },	/* must be table entry 1 */
54 	{ "break",	'\0',	FLOW,	NULL },	/* rarely in cross-reference */
55 	{ "case",	' ',	FLOW,	NULL },
56 	{ "char",	' ',	DECL,	NULL },
57 	{ "continue",	'\0',	FLOW,	NULL },	/* rarely in cross-reference */
58 	{ "default",	'\0',	FLOW,	NULL },	/* rarely in cross-reference */
59 	{ "#define",	' ',	MISC,	NULL },	/* must be table entry 7 */
60 	{ "double",	' ',	DECL,	NULL },
61 	{ "\t",		'\0',	MISC,	NULL },	/* must be table entry 9 */
62 	{ "\n",		'\0',	MISC,	NULL },	/* must be table entry 10 */
63 	{ "else",	' ',	FLOW,	NULL },
64 	{ "enum",	' ',	DECL,	NULL },
65 	{ externtext,	' ',	DECL,	NULL },
66 	{ "float",	' ',	DECL,	NULL },
67 	{ "for",	'(',	FLOW,	NULL },
68 	{ "goto",	' ',	FLOW,	NULL },
69 	{ "if",		'(',	FLOW,	NULL },
70 	{ "int",	' ',	DECL,	NULL },
71 	{ "long",	' ',	DECL,	NULL },
72 	{ "register",	' ',	DECL,	NULL },
73 	{ "return",	'\0',	FLOW,	NULL },
74 	{ "short",	' ',	DECL,	NULL },
75 	{ "sizeof",	'\0',	MISC,	NULL },
76 	{ "static",	' ',	DECL,	NULL },
77 	{ "struct",	' ',	DECL,	NULL },
78 	{ "switch",	'(',	FLOW,	NULL },
79 	{ typedeftext,	' ',	DECL,	NULL },
80 	{ "union",	' ',	DECL,	NULL },
81 	{ "unsigned",	' ',	DECL,	NULL },
82 	{ "void",	' ',	DECL,	NULL },
83 	{ "while",	'(',	FLOW,	NULL },
84 
85 	/* these keywords are not compressed */
86 	{ "auto",	' ',	DECL,	NULL },
87 	{ "do",		' ',	FLOW,	NULL },
88 	{ "fortran",	' ',	DECL,	NULL },
89 	{ "const",	' ',	DECL,	NULL },
90 	{ "signed",	' ',	DECL,	NULL },
91 	{ "volatile",	' ',	DECL,	NULL },
92 };
93 
94 #define	KEYWORDS	(sizeof (keyword) / sizeof (struct keystruct))
95 
96 #define	HASHMOD	(KEYWORDS * 2 + 1)
97 
98 static	struct	keystruct *hashtab[HASHMOD]; /* pointer table */
99 
100 /* put the keywords into the symbol table */
101 
102 void
103 initsymtab(void)
104 {
105 	int	i, j;
106 	struct	keystruct *p;
107 
108 	for (i = 1; i < KEYWORDS; ++i) {
109 		p = &keyword[i];
110 		j = hash(p->text) % HASHMOD;
111 		p->next = hashtab[j];
112 		hashtab[j] = p;
113 	}
114 }
115 
116 /* see if this identifier is a keyword */
117 
118 struct keystruct *
119 lookup(char *ident)
120 {
121 	struct	keystruct *p;
122 	int	c;
123 
124 	/* look up the identifier in the keyword table */
125 	for (p = hashtab[hash(ident) % HASHMOD]; p != NULL; p = p->next) {
126 		if (strequal(ident, p->text)) {
127 			if (compress == YES && (c = p - keyword) < ' ') {
128 				ident[0] = c;	/* compress the keyword */
129 			}
130 			return (p);
131 		}
132 	}
133 	/* this is an identifier */
134 	return (NULL);
135 }
136 
137 /* form hash value for string */
138 
139 int
140 hash(char *s)
141 {
142 	unsigned i;
143 
144 	for (i = 0; *s != '\0'; )
145 		i += *s++;	/* += is faster than <<= for cscope */
146 	return (i);
147 }
148