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 parser for dc.
33 *
34 */
35
36 #if DC_ENABLED
37
38 #include <assert.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <setjmp.h>
42
43 #include <dc.h>
44 #include <program.h>
45 #include <vm.h>
46
dc_parse_register(BcParse * p,bool var)47 static void dc_parse_register(BcParse *p, bool var) {
48
49 bc_lex_next(&p->l);
50 if (p->l.t != BC_LEX_NAME) bc_parse_err(p, BC_ERR_PARSE_TOKEN);
51
52 bc_parse_pushName(p, p->l.str.v, var);
53 }
54
dc_parse_string(BcParse * p)55 static inline void dc_parse_string(BcParse *p) {
56 bc_parse_addString(p);
57 bc_lex_next(&p->l);
58 }
59
dc_parse_mem(BcParse * p,uchar inst,bool name,bool store)60 static void dc_parse_mem(BcParse *p, uchar inst, bool name, bool store) {
61
62 bc_parse_push(p, inst);
63
64 if (name) dc_parse_register(p, inst != BC_INST_ARRAY_ELEM);
65
66 if (store) {
67 bc_parse_push(p, BC_INST_SWAP);
68 bc_parse_push(p, BC_INST_ASSIGN_NO_VAL);
69 }
70
71 bc_lex_next(&p->l);
72 }
73
dc_parse_cond(BcParse * p,uchar inst)74 static void dc_parse_cond(BcParse *p, uchar inst) {
75
76 bc_parse_push(p, inst);
77 bc_parse_push(p, BC_INST_EXEC_COND);
78
79 dc_parse_register(p, true);
80
81 bc_lex_next(&p->l);
82
83 if (p->l.t == BC_LEX_KW_ELSE) {
84 dc_parse_register(p, true);
85 bc_lex_next(&p->l);
86 }
87 else bc_parse_pushIndex(p, SIZE_MAX);
88 }
89
dc_parse_token(BcParse * p,BcLexType t,uint8_t flags)90 static void dc_parse_token(BcParse *p, BcLexType t, uint8_t flags) {
91
92 uchar inst;
93 bool assign, get_token = false;
94
95 switch (t) {
96
97 case BC_LEX_OP_REL_EQ:
98 case BC_LEX_OP_REL_LE:
99 case BC_LEX_OP_REL_GE:
100 case BC_LEX_OP_REL_NE:
101 case BC_LEX_OP_REL_LT:
102 case BC_LEX_OP_REL_GT:
103 {
104 inst = (uchar) (t - BC_LEX_OP_REL_EQ + BC_INST_REL_EQ);
105 dc_parse_cond(p, inst);
106 break;
107 }
108
109 case BC_LEX_SCOLON:
110 case BC_LEX_COLON:
111 {
112 dc_parse_mem(p, BC_INST_ARRAY_ELEM, true, t == BC_LEX_COLON);
113 break;
114 }
115
116 case BC_LEX_STR:
117 {
118 dc_parse_string(p);
119 break;
120 }
121
122 case BC_LEX_NEG:
123 {
124 if (dc_lex_negCommand(&p->l)) {
125 bc_parse_push(p, BC_INST_NEG);
126 get_token = true;
127 break;
128 }
129
130 bc_lex_next(&p->l);
131 }
132 // Fallthrough.
133 BC_FALLTHROUGH
134
135 case BC_LEX_NUMBER:
136 {
137 bc_parse_number(p);
138
139 if (t == BC_LEX_NEG) bc_parse_push(p, BC_INST_NEG);
140 get_token = true;
141
142 break;
143 }
144
145 case BC_LEX_KW_READ:
146 {
147 if (BC_ERR(flags & BC_PARSE_NOREAD))
148 bc_parse_err(p, BC_ERR_EXEC_REC_READ);
149 else bc_parse_push(p, BC_INST_READ);
150 get_token = true;
151 break;
152 }
153
154 case BC_LEX_OP_ASSIGN:
155 case BC_LEX_STORE_PUSH:
156 {
157 assign = t == BC_LEX_OP_ASSIGN;
158 inst = assign ? BC_INST_VAR : BC_INST_PUSH_TO_VAR;
159 dc_parse_mem(p, inst, true, assign);
160 break;
161 }
162
163 case BC_LEX_LOAD:
164 case BC_LEX_LOAD_POP:
165 {
166 inst = t == BC_LEX_LOAD_POP ? BC_INST_PUSH_VAR : BC_INST_LOAD;
167 dc_parse_mem(p, inst, true, false);
168 break;
169 }
170
171 case BC_LEX_STORE_IBASE:
172 case BC_LEX_STORE_OBASE:
173 case BC_LEX_STORE_SCALE:
174 #if BC_ENABLE_EXTRA_MATH
175 case BC_LEX_STORE_SEED:
176 #endif // BC_ENABLE_EXTRA_MATH
177 {
178 inst = (uchar) (t - BC_LEX_STORE_IBASE + BC_INST_IBASE);
179 dc_parse_mem(p, inst, false, true);
180 break;
181 }
182
183 default:
184 {
185 bc_parse_err(p, BC_ERR_PARSE_TOKEN);
186 }
187 }
188
189 if (get_token) bc_lex_next(&p->l);
190 }
191
dc_parse_expr(BcParse * p,uint8_t flags)192 void dc_parse_expr(BcParse *p, uint8_t flags) {
193
194 BcInst inst;
195 BcLexType t;
196 bool have_expr = false, need_expr = (flags & BC_PARSE_NOREAD) != 0;
197
198 while ((t = p->l.t) != BC_LEX_EOF) {
199
200 if (t == BC_LEX_NLINE) {
201 bc_lex_next(&p->l);
202 continue;
203 }
204
205 inst = dc_parse_insts[t];
206
207 if (inst != BC_INST_INVALID) {
208 bc_parse_push(p, inst);
209 bc_lex_next(&p->l);
210 }
211 else dc_parse_token(p, t, flags);
212
213 have_expr = true;
214 }
215
216 if (BC_ERR(need_expr && !have_expr))
217 bc_vm_err(BC_ERR_EXEC_READ_EXPR);
218 else if (p->l.t == BC_LEX_EOF && (flags & BC_PARSE_NOCALL))
219 bc_parse_push(p, BC_INST_POP_EXEC);
220 }
221
dc_parse_parse(BcParse * p)222 void dc_parse_parse(BcParse *p) {
223
224 assert(p != NULL);
225
226 BC_SETJMP(exit);
227
228 if (BC_ERR(p->l.t == BC_LEX_EOF)) bc_parse_err(p, BC_ERR_PARSE_EOF);
229 else dc_parse_expr(p, 0);
230
231 exit:
232 BC_SIG_MAYLOCK;
233 if (BC_ERR(vm.status || vm.sig)) bc_parse_reset(p);
234 BC_LONGJMP_CONT;
235 }
236 #endif // DC_ENABLED
237