1 /*
2 * *****************************************************************************
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 *
6 * Copyright (c) 2018-2021 Gavin D. Howard and contributors.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * * Redistributions of source code must retain the above copyright notice, this
12 * list of conditions and the following disclaimer.
13 *
14 * * Redistributions in binary form must reproduce the above copyright notice,
15 * this list of conditions and the following disclaimer in the documentation
16 * and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 *
30 * *****************************************************************************
31 *
32 * The lexer for dc.
33 *
34 */
35
36 #if DC_ENABLED
37
38 #include <ctype.h>
39
40 #include <dc.h>
41 #include <vm.h>
42
dc_lex_negCommand(BcLex * l)43 bool dc_lex_negCommand(BcLex *l) {
44 char c = l->buf[l->i];
45 return !BC_LEX_NUM_CHAR(c, false, false);
46 }
47
dc_lex_register(BcLex * l)48 static void dc_lex_register(BcLex *l) {
49
50 if (DC_X && isspace(l->buf[l->i - 1])) {
51
52 char c;
53
54 bc_lex_whitespace(l);
55 c = l->buf[l->i];
56
57 if (!isalnum(c) && c != '_')
58 bc_lex_verr(l, BC_ERR_PARSE_CHAR, c);
59
60 l->i += 1;
61 bc_lex_name(l);
62 }
63 else {
64 bc_vec_popAll(&l->str);
65 bc_vec_pushByte(&l->str, (uchar) l->buf[l->i - 1]);
66 bc_vec_pushByte(&l->str, '\0');
67 l->t = BC_LEX_NAME;
68 }
69 }
70
dc_lex_string(BcLex * l)71 static void dc_lex_string(BcLex *l) {
72
73 size_t depth = 1, nls = 0, i = l->i;
74 char c;
75
76 l->t = BC_LEX_STR;
77 bc_vec_popAll(&l->str);
78
79 for (; (c = l->buf[i]) && depth; ++i) {
80
81 if (c == '\\') {
82 c = l->buf[++i];
83 if (!c) break;
84 }
85 else {
86 depth += (c == '[');
87 depth -= (c == ']');
88 }
89
90 nls += (c == '\n');
91
92 if (depth) bc_vec_push(&l->str, &c);
93 }
94
95 if (BC_ERR(c == '\0' && depth)) {
96 l->i = i;
97 bc_lex_err(l, BC_ERR_PARSE_STRING);
98 }
99
100 bc_vec_pushByte(&l->str, '\0');
101
102 l->i = i;
103 l->line += nls;
104 }
105
dc_lex_token(BcLex * l)106 void dc_lex_token(BcLex *l) {
107
108 char c = l->buf[l->i++], c2;
109 size_t i;
110
111 for (i = 0; i < dc_lex_regs_len; ++i) {
112 if (l->last == dc_lex_regs[i]) {
113 dc_lex_register(l);
114 return;
115 }
116 }
117
118 if (c >= '"' && c <= '~' &&
119 (l->t = dc_lex_tokens[(c - '"')]) != BC_LEX_INVALID)
120 {
121 return;
122 }
123
124 // This is the workhorse of the lexer.
125 switch (c) {
126
127 case '\0':
128 case '\n':
129 case '\t':
130 case '\v':
131 case '\f':
132 case '\r':
133 case ' ':
134 {
135 bc_lex_commonTokens(l, c);
136 break;
137 }
138
139 case '!':
140 {
141 c2 = l->buf[l->i];
142
143 if (c2 == '=') l->t = BC_LEX_OP_REL_NE;
144 else if (c2 == '<') l->t = BC_LEX_OP_REL_LE;
145 else if (c2 == '>') l->t = BC_LEX_OP_REL_GE;
146 else bc_lex_invalidChar(l, c);
147
148 l->i += 1;
149 break;
150 }
151
152 case '#':
153 {
154 bc_lex_lineComment(l);
155 break;
156 }
157
158 case '.':
159 {
160 c2 = l->buf[l->i];
161 if (BC_NO_ERR(BC_LEX_NUM_CHAR(c2, true, false)))
162 bc_lex_number(l, c);
163 else bc_lex_invalidChar(l, c);
164 break;
165 }
166
167 case '0':
168 case '1':
169 case '2':
170 case '3':
171 case '4':
172 case '5':
173 case '6':
174 case '7':
175 case '8':
176 case '9':
177 case 'A':
178 case 'B':
179 case 'C':
180 case 'D':
181 case 'E':
182 case 'F':
183 {
184 bc_lex_number(l, c);
185 break;
186 }
187
188 case '[':
189 {
190 dc_lex_string(l);
191 break;
192 }
193
194 default:
195 {
196 bc_lex_invalidChar(l, c);
197 }
198 }
199 }
200 #endif // DC_ENABLED
201