xref: /freebsd/contrib/bc/src/parse.c (revision 5bb3134a8c21cb87b30e135ef168483f0333dabb)
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  * Code common to the parsers.
33  *
34  */
35 
36 #include <assert.h>
37 #include <stddef.h>
38 #include <stdlib.h>
39 #include <string.h>
40 
41 #include <limits.h>
42 
43 #include <parse.h>
44 #include <program.h>
45 #include <vm.h>
46 
47 void bc_parse_updateFunc(BcParse *p, size_t fidx) {
48 	p->fidx = fidx;
49 	p->func = bc_vec_item(&p->prog->fns, fidx);
50 }
51 
52 inline void bc_parse_pushName(const BcParse *p, char *name, bool var) {
53 	bc_parse_pushIndex(p, bc_program_search(p->prog, name, var));
54 }
55 
56 /**
57  * Updates the function, then pushes the instruction and the index. This is a
58  * convenience function.
59  * @param p     The parser.
60  * @param inst  The instruction to push.
61  * @param idx   The index to push.
62  */
63 static void bc_parse_update(BcParse *p, uchar inst, size_t idx) {
64 	bc_parse_updateFunc(p, p->fidx);
65 	bc_parse_push(p, inst);
66 	bc_parse_pushIndex(p, idx);
67 }
68 
69 void bc_parse_addString(BcParse *p) {
70 
71 	size_t idx;
72 
73 	BC_SIG_LOCK;
74 
75 	idx = bc_program_addString(p->prog, p->l.str.v, p->fidx);
76 
77 	// Push the string info.
78 	bc_parse_update(p, BC_INST_STR, p->fidx);
79 	bc_parse_pushIndex(p, idx);
80 
81 	BC_SIG_UNLOCK;
82 }
83 
84 static void bc_parse_addNum(BcParse *p, const char *string) {
85 
86 	BcVec *consts = &p->func->consts;
87 	size_t idx;
88 	BcConst *c;
89 	BcVec *slabs;
90 
91 	// Special case 0.
92 	if (bc_parse_zero[0] == string[0] && bc_parse_zero[1] == string[1]) {
93 		bc_parse_push(p, BC_INST_ZERO);
94 		return;
95 	}
96 
97 	// Special case 1.
98 	if (bc_parse_one[0] == string[0] && bc_parse_one[1] == string[1]) {
99 		bc_parse_push(p, BC_INST_ONE);
100 		return;
101 	}
102 
103 	// Get the index.
104 	idx = consts->len;
105 
106 	BC_SIG_LOCK;
107 
108 	// Get the right slab.
109 	slabs = p->fidx == BC_PROG_MAIN || p->fidx == BC_PROG_READ ?
110 	        &vm.main_const_slab : &vm.other_slabs;
111 
112 	// Push an empty constant.
113 	c = bc_vec_pushEmpty(consts);
114 
115 	// Set the fields.
116 	c->val = bc_slabvec_strdup(slabs, string);
117 	c->base = BC_NUM_BIGDIG_MAX;
118 
119 	// We need this to be able to tell that the number has not been allocated.
120 	bc_num_clear(&c->num);
121 
122 	bc_parse_update(p, BC_INST_NUM, idx);
123 
124 	BC_SIG_UNLOCK;
125 }
126 
127 void bc_parse_number(BcParse *p) {
128 
129 #if BC_ENABLE_EXTRA_MATH
130 	char *exp = strchr(p->l.str.v, 'e');
131 	size_t idx = SIZE_MAX;
132 
133 	// Do we have a number in scientific notation? If so, add a nul byte where
134 	// the e is.
135 	if (exp != NULL) {
136 		idx = ((size_t) (exp - p->l.str.v));
137 		*exp = 0;
138 	}
139 #endif // BC_ENABLE_EXTRA_MATH
140 
141 	bc_parse_addNum(p, p->l.str.v);
142 
143 #if BC_ENABLE_EXTRA_MATH
144 	// If we have a number in scientific notation...
145 	if (exp != NULL) {
146 
147 		bool neg;
148 
149 		// Figure out if the exponent is negative.
150 		neg = (*((char*) bc_vec_item(&p->l.str, idx + 1)) == BC_LEX_NEG_CHAR);
151 
152 		// Add the number and instruction.
153 		bc_parse_addNum(p, bc_vec_item(&p->l.str, idx + 1 + neg));
154 		bc_parse_push(p, BC_INST_LSHIFT + neg);
155 	}
156 #endif // BC_ENABLE_EXTRA_MATH
157 }
158 
159 void bc_parse_text(BcParse *p, const char *text, bool is_stdin) {
160 
161 	// Make sure the pointer isn't invalidated.
162 	p->func = bc_vec_item(&p->prog->fns, p->fidx);
163 	bc_lex_text(&p->l, text, is_stdin);
164 }
165 
166 void bc_parse_reset(BcParse *p) {
167 
168 	BC_SIG_ASSERT_LOCKED;
169 
170 	// Reset the function if it isn't main and switch to main.
171 	if (p->fidx != BC_PROG_MAIN) {
172 		bc_func_reset(p->func);
173 		bc_parse_updateFunc(p, BC_PROG_MAIN);
174 	}
175 
176 	// Reset the lexer.
177 	p->l.i = p->l.len;
178 	p->l.t = BC_LEX_EOF;
179 
180 #if BC_ENABLED
181 	if (BC_IS_BC) {
182 
183 		// Get rid of the bc parser state.
184 		p->auto_part = false;
185 		bc_vec_npop(&p->flags, p->flags.len - 1);
186 		bc_vec_popAll(&p->exits);
187 		bc_vec_popAll(&p->conds);
188 		bc_vec_popAll(&p->ops);
189 	}
190 #endif // BC_ENABLED
191 
192 	// Reset the program. This might clear the error.
193 	bc_program_reset(p->prog);
194 
195 	// Jump if there is an error.
196 	if (BC_ERR(vm.status)) BC_JMP;
197 }
198 
199 #ifndef NDEBUG
200 void bc_parse_free(BcParse *p) {
201 
202 	BC_SIG_ASSERT_LOCKED;
203 
204 	assert(p != NULL);
205 
206 #if BC_ENABLED
207 	if (BC_IS_BC) {
208 		bc_vec_free(&p->flags);
209 		bc_vec_free(&p->exits);
210 		bc_vec_free(&p->conds);
211 		bc_vec_free(&p->ops);
212 		bc_vec_free(&p->buf);
213 	}
214 #endif // BC_ENABLED
215 
216 	bc_lex_free(&p->l);
217 }
218 #endif // NDEBUG
219 
220 void bc_parse_init(BcParse *p, BcProgram *prog, size_t func) {
221 
222 #if BC_ENABLED
223 	uint16_t flag = 0;
224 #endif // BC_ENABLED
225 
226 	BC_SIG_ASSERT_LOCKED;
227 
228 	assert(p != NULL && prog != NULL);
229 
230 #if BC_ENABLED
231 	if (BC_IS_BC) {
232 
233 		// We always want at least one flag set on the flags stack.
234 		bc_vec_init(&p->flags, sizeof(uint16_t), BC_DTOR_NONE);
235 		bc_vec_push(&p->flags, &flag);
236 
237 		bc_vec_init(&p->exits, sizeof(BcInstPtr), BC_DTOR_NONE);
238 		bc_vec_init(&p->conds, sizeof(size_t), BC_DTOR_NONE);
239 		bc_vec_init(&p->ops, sizeof(BcLexType), BC_DTOR_NONE);
240 		bc_vec_init(&p->buf, sizeof(char), BC_DTOR_NONE);
241 
242 		p->auto_part = false;
243 	}
244 #endif // BC_ENABLED
245 
246 	bc_lex_init(&p->l);
247 
248 	// Set up the function.
249 	p->prog = prog;
250 	bc_parse_updateFunc(p, func);
251 }
252