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Diffstat (limited to 'src/lookup.c')
| -rw-r--r-- | src/lookup.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/src/lookup.c b/src/lookup.c new file mode 100644 index 0000000..809dff9 --- /dev/null +++ b/src/lookup.c @@ -0,0 +1,151 @@ +/*=========================================================================== + Copyright (c) 1998-2000, The Santa Cruz Operation + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + *Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + + *Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + + *Neither name of The Santa Cruz Operation nor the names of its contributors + may be used to endorse or promote products derived from this software + without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS + IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) + HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH + DAMAGE. + =========================================================================*/ + +/* cscope - interactive C symbol cross-reference + * + * keyword look-up routine for the C symbol scanner + */ + +#include "global.h" +#include "lookup.h" + +static char const rcsid[] = "$Id: lookup.c,v 1.4 2006/04/21 10:45:48 broeker Exp $"; + +/* keyword text for fast testing of keywords in the scanner */ +char enumtext[] = "enum"; +char externtext[] = "extern"; +char structtext[] = "struct"; +char typedeftext[] = "typedef"; +char uniontext[] = "union"; + +/* This keyword table is also used for keyword text compression. Keywords + * with an index less than the numeric value of a space are replaced with the + * control character corresponding to the index, so they cannot be moved + * without changing the database file version and adding compatibility code + * for old databases. + */ +struct keystruct keyword[] = { + {"", '\0', NULL}, /* dummy entry */ + {"#define", ' ', NULL}, /* must be table entry 1 */ + {"#include", ' ', NULL}, /* must be table entry 2 */ + {"break", '\0', NULL}, /* rarely in cross-reference */ + {"case", ' ', NULL}, + {"char", ' ', NULL}, + {"continue", '\0', NULL}, /* rarely in cross-reference */ + {"default", '\0', NULL}, /* rarely in cross-reference */ + {"double", ' ', NULL}, + {"\t", '\0', NULL}, /* must be the table entry 9 */ + {"\n", '\0', NULL}, /* must be the table entry 10 */ + {"else", ' ', NULL}, + {enumtext, ' ', NULL}, + {externtext, ' ', NULL}, + {"float", ' ', NULL}, + {"for", '(', NULL}, + {"goto", ' ', NULL}, + {"if", '(', NULL}, + {"int", ' ', NULL}, + {"long", ' ', NULL}, + {"register", ' ', NULL}, + {"return", '\0', NULL}, + {"short", ' ', NULL}, + {"sizeof", '\0', NULL}, + {"static", ' ', NULL}, + {structtext, ' ', NULL}, + {"switch", '(', NULL}, + {typedeftext, ' ', NULL}, + {uniontext, ' ', NULL}, + {"unsigned", ' ', NULL}, + {"void", ' ', NULL}, + {"while", '(', NULL}, + + /* these keywords are not compressed */ + {"do", '\0', NULL}, + {"auto", ' ', NULL}, + {"fortran", ' ', NULL}, + {"const", ' ', NULL}, + {"signed", ' ', NULL}, + {"volatile", ' ', NULL}, +}; +#define KEYWORDS (sizeof(keyword) / sizeof(struct keystruct)) + +#define HASHMOD (KEYWORDS * 2 + 1) + +static struct keystruct *hashtab[HASHMOD]; /* pointer table */ + +/* put the keywords into the symbol table */ + +void +initsymtab(void) +{ + unsigned int i, j; + struct keystruct *p; + + for (i = 1; i < KEYWORDS; ++i) { + p = keyword + i; + j = hash(p->text) % HASHMOD; + p->next = hashtab[j]; + hashtab[j] = p; + } +} + +/* see if this identifier is a keyword */ + +char * +lookup(char *ident) +{ + struct keystruct *p; + int c; + + /* look up the identifier in the keyword table */ + for (p = hashtab[hash(ident) % HASHMOD]; p != NULL; p = p->next) { + if (strequal(ident, p->text)) { + if (compress == YES && (c = p - keyword) < ' ') { + ident[0] = c; /* compress the keyword */ + } + return(p->text); + } + } + /* this is an identifier */ + return(NULL); +} + +/* form hash value for string */ +int +hash(char *ss) +{ + int i; + unsigned char *s = (unsigned char *)ss; + + for (i = 0; *s != '\0'; ) + i += *s++; /* += is faster than <<= for cscope */ + return(i); +} |