FreeBSD/Linux Kernel Cross Reference
sys/boot/ficl/prefix.c
1 /*******************************************************************
2 ** p r e f i x . c
3 ** Forth Inspired Command Language
4 ** Parser extensions for Ficl
5 ** Authors: Larry Hastings & John Sadler (john_sadler@alum.mit.edu)
6 ** Created: April 2001
7 ** $Id: prefix.c,v 1.6 2001/12/05 07:21:34 jsadler Exp $
8 *******************************************************************/
9 /*
10 ** Copyright (c) 1997-2001 John Sadler (john_sadler@alum.mit.edu)
11 ** All rights reserved.
12 **
13 ** Get the latest Ficl release at http://ficl.sourceforge.net
14 **
15 ** I am interested in hearing from anyone who uses ficl. If you have
16 ** a problem, a success story, a defect, an enhancement request, or
17 ** if you would like to contribute to the ficl release, please
18 ** contact me by email at the address above.
19 **
20 ** L I C E N S E and D I S C L A I M E R
21 **
22 ** Redistribution and use in source and binary forms, with or without
23 ** modification, are permitted provided that the following conditions
24 ** are met:
25 ** 1. Redistributions of source code must retain the above copyright
26 ** notice, this list of conditions and the following disclaimer.
27 ** 2. Redistributions in binary form must reproduce the above copyright
28 ** notice, this list of conditions and the following disclaimer in the
29 ** documentation and/or other materials provided with the distribution.
30 **
31 ** THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
32 ** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33 ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34 ** ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
35 ** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 ** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 ** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 ** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39 ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40 ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41 ** SUCH DAMAGE.
42 */
43
44 /* $FreeBSD: src/sys/boot/ficl/prefix.c,v 1.3 2002/08/31 01:04:53 scottl Exp $ */
45
46 #include <string.h>
47 #include <ctype.h>
48 #include "ficl.h"
49 #include "math64.h"
50
51 /*
52 ** (jws) revisions:
53 ** A prefix is a word in a dedicated wordlist (name stored in list_name below)
54 ** that is searched in a special way by the prefix parse step. When a prefix
55 ** matches the beginning of an incoming token, push the non-prefix part of the
56 ** token back onto the input stream and execute the prefix code.
57 **
58 ** The parse step is called ficlParsePrefix.
59 ** Storing prefix entries in the dictionary greatly simplifies
60 ** the process of matching and dispatching prefixes, avoids the
61 ** need to clean up a dynamically allocated prefix list when the system
62 ** goes away, but still allows prefixes to be allocated at runtime.
63 */
64
65 static char list_name[] = "<prefixes>";
66
67 /**************************************************************************
68 f i c l P a r s e P r e f i x
69 ** This is the parse step for prefixes - it checks an incoming word
70 ** to see if it starts with a prefix, and if so runs the corrseponding
71 ** code against the remainder of the word and returns true.
72 **************************************************************************/
73 int ficlParsePrefix(FICL_VM *pVM, STRINGINFO si)
74 {
75 int i;
76 FICL_HASH *pHash;
77 FICL_WORD *pFW = ficlLookup(pVM->pSys, list_name);
78
79 /*
80 ** Make sure we found the prefix dictionary - otherwise silently fail
81 ** If forth-wordlist is not in the search order, we won't find the prefixes.
82 */
83 if (!pFW)
84 return FICL_FALSE;
85
86 pHash = (FICL_HASH *)(pFW->param[0].p);
87 /*
88 ** Walk the list looking for a match with the beginning of the incoming token
89 */
90 for (i = 0; i < (int)pHash->size; i++)
91 {
92 pFW = pHash->table[i];
93 while (pFW != NULL)
94 {
95 int n;
96 n = pFW->nName;
97 /*
98 ** If we find a match, adjust the TIB to give back the non-prefix characters
99 ** and execute the prefix word.
100 */
101 if (!strincmp(SI_PTR(si), pFW->name, (FICL_UNS)n))
102 {
103 /* (sadler) fixed off-by-one error when the token has no trailing space in the TIB */
104 vmSetTibIndex(pVM, si.cp + n - pVM->tib.cp );
105 vmExecute(pVM, pFW);
106
107 return (int)FICL_TRUE;
108 }
109 pFW = pFW->link;
110 }
111 }
112
113 return FICL_FALSE;
114 }
115
116
117 static void tempBase(FICL_VM *pVM, int base)
118 {
119 int oldbase = pVM->base;
120 STRINGINFO si = vmGetWord0(pVM);
121
122 pVM->base = base;
123 if (!ficlParseNumber(pVM, si))
124 {
125 int i = SI_COUNT(si);
126 vmThrowErr(pVM, "%.*s not recognized", i, SI_PTR(si));
127 }
128
129 pVM->base = oldbase;
130 return;
131 }
132
133 static void fTempBase(FICL_VM *pVM)
134 {
135 int base = stackPopINT(pVM->pStack);
136 tempBase(pVM, base);
137 return;
138 }
139
140 static void prefixHex(FICL_VM *pVM)
141 {
142 tempBase(pVM, 16);
143 }
144
145 static void prefixTen(FICL_VM *pVM)
146 {
147 tempBase(pVM, 10);
148 }
149
150
151 /**************************************************************************
152 f i c l C o m p i l e P r e f i x
153 ** Build prefix support into the dictionary and the parser
154 ** Note: since prefixes always execute, they are effectively IMMEDIATE.
155 ** If they need to generate code in compile state you must add
156 ** this code explicitly.
157 **************************************************************************/
158 void ficlCompilePrefix(FICL_SYSTEM *pSys)
159 {
160 FICL_DICT *dp = pSys->dp;
161 FICL_HASH *pHash;
162 FICL_HASH *pPrevCompile = dp->pCompile;
163 #if (FICL_EXTENDED_PREFIX)
164 FICL_WORD *pFW;
165 #endif
166
167 /*
168 ** Create a named wordlist for prefixes to reside in...
169 ** Since we're doing a special kind of search, make it
170 ** a single bucket hashtable - hashing does not help here.
171 */
172 pHash = dictCreateWordlist(dp, 1);
173 pHash->name = list_name;
174 dictAppendWord(dp, list_name, constantParen, FW_DEFAULT);
175 dictAppendCell(dp, LVALUEtoCELL(pHash));
176
177 /*
178 ** Put __tempbase in the forth-wordlist
179 */
180 dictAppendWord(dp, "__tempbase", fTempBase, FW_DEFAULT);
181
182 /*
183 ** Temporarily make the prefix list the compile wordlist so that
184 ** we can create some precompiled prefixes.
185 */
186 dp->pCompile = pHash;
187 dictAppendWord(dp, "0x", prefixHex, FW_DEFAULT);
188 dictAppendWord(dp, "0d", prefixTen, FW_DEFAULT);
189 #if (FICL_EXTENDED_PREFIX)
190 pFW = ficlLookup(pSys, "\\");
191 if (pFW)
192 {
193 dictAppendWord(dp, "//", pFW->code, FW_DEFAULT);
194 }
195 #endif
196 dp->pCompile = pPrevCompile;
197
198 return;
199 }
200 Cache object: 5c8cd378dc238658c8a5ea823aac98cc
|