1 /* 2 * ***************************************************************************** 3 * 4 * SPDX-License-Identifier: BSD-2-Clause 5 * 6 * Copyright (c) 2018-2023 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 48 bc_parse_updateFunc(BcParse* p, size_t fidx) 49 { 50 p->fidx = fidx; 51 p->func = bc_vec_item(&p->prog->fns, fidx); 52 } 53 54 inline void 55 bc_parse_pushName(const BcParse* p, char* name, bool var) 56 { 57 bc_parse_pushIndex(p, bc_program_search(p->prog, name, var)); 58 } 59 60 /** 61 * Updates the function, then pushes the instruction and the index. This is a 62 * convenience function. 63 * @param p The parser. 64 * @param inst The instruction to push. 65 * @param idx The index to push. 66 */ 67 static inline void 68 bc_parse_pushInstIdx(BcParse* p, uchar inst, size_t idx) 69 { 70 bc_parse_push(p, inst); 71 bc_parse_pushIndex(p, idx); 72 } 73 74 void 75 bc_parse_addString(BcParse* p) 76 { 77 size_t idx; 78 79 idx = bc_program_addString(p->prog, p->l.str.v); 80 81 // Push the string info. 82 bc_parse_pushInstIdx(p, BC_INST_STR, idx); 83 } 84 85 static void 86 bc_parse_addNum(BcParse* p, const char* string) 87 { 88 BcProgram* prog = p->prog; 89 size_t idx; 90 91 // XXX: This function has an implicit assumption: that string is a valid C 92 // string with a nul terminator. This is because of the unchecked array 93 // accesses below. I can't check this with an assert() because that could 94 // lead to out-of-bounds access. 95 // 96 // XXX: In fact, just for safety's sake, assume that this function needs a 97 // non-empty string with a nul terminator, just in case bc_parse_zero or 98 // bc_parse_one change in the future, which I doubt. 99 100 BC_SIG_ASSERT_LOCKED; 101 102 // Special case 0. 103 if (bc_parse_zero[0] == string[0] && bc_parse_zero[1] == string[1]) 104 { 105 bc_parse_push(p, BC_INST_ZERO); 106 return; 107 } 108 109 // Special case 1. 110 if (bc_parse_one[0] == string[0] && bc_parse_one[1] == string[1]) 111 { 112 bc_parse_push(p, BC_INST_ONE); 113 return; 114 } 115 116 if (bc_map_insert(&prog->const_map, string, prog->consts.len, &idx)) 117 { 118 BcConst* c; 119 BcId* id = bc_vec_item(&prog->const_map, idx); 120 121 // Get the index. 122 idx = id->idx; 123 124 // Push an empty constant. 125 c = bc_vec_pushEmpty(&prog->consts); 126 127 // Set the fields. We reuse the string in the ID (allocated by 128 // bc_map_insert()), because why not? 129 c->val = id->name; 130 c->base = BC_NUM_BIGDIG_MAX; 131 132 // We need this to be able to tell that the number has not been 133 // allocated. 134 bc_num_clear(&c->num); 135 } 136 else 137 { 138 BcId* id = bc_vec_item(&prog->const_map, idx); 139 idx = id->idx; 140 } 141 142 bc_parse_pushInstIdx(p, BC_INST_NUM, idx); 143 } 144 145 void 146 bc_parse_number(BcParse* p) 147 { 148 #if BC_ENABLE_EXTRA_MATH 149 char* exp = strchr(p->l.str.v, 'e'); 150 size_t idx = SIZE_MAX; 151 152 // Do we have a number in scientific notation? If so, add a nul byte where 153 // the e is. 154 if (exp != NULL) 155 { 156 idx = ((size_t) (exp - p->l.str.v)); 157 *exp = 0; 158 } 159 #endif // BC_ENABLE_EXTRA_MATH 160 161 bc_parse_addNum(p, p->l.str.v); 162 163 #if BC_ENABLE_EXTRA_MATH 164 // If we have a number in scientific notation... 165 if (exp != NULL) 166 { 167 bool neg; 168 169 // Figure out if the exponent is negative. 170 neg = (*((char*) bc_vec_item(&p->l.str, idx + 1)) == BC_LEX_NEG_CHAR); 171 172 // Add the number and instruction. 173 bc_parse_addNum(p, bc_vec_item(&p->l.str, idx + 1 + neg)); 174 bc_parse_push(p, BC_INST_LSHIFT + neg); 175 } 176 #endif // BC_ENABLE_EXTRA_MATH 177 } 178 179 void 180 bc_parse_text(BcParse* p, const char* text, BcMode mode) 181 { 182 BC_SIG_LOCK; 183 184 // Make sure the pointer isn't invalidated. 185 p->func = bc_vec_item(&p->prog->fns, p->fidx); 186 bc_lex_text(&p->l, text, mode); 187 188 BC_SIG_UNLOCK; 189 } 190 191 void 192 bc_parse_reset(BcParse* p) 193 { 194 BC_SIG_ASSERT_LOCKED; 195 196 // Reset the function if it isn't main and switch to main. 197 if (p->fidx != BC_PROG_MAIN) 198 { 199 bc_func_reset(p->func); 200 bc_parse_updateFunc(p, BC_PROG_MAIN); 201 } 202 203 // Reset the lexer. 204 p->l.i = p->l.len; 205 p->l.t = BC_LEX_EOF; 206 207 #if BC_ENABLED 208 if (BC_IS_BC) 209 { 210 // Get rid of the bc parser state. 211 p->auto_part = false; 212 bc_vec_npop(&p->flags, p->flags.len - 1); 213 bc_vec_popAll(&p->exits); 214 bc_vec_popAll(&p->conds); 215 bc_vec_popAll(&p->ops); 216 } 217 #endif // BC_ENABLED 218 219 // Reset the program. This might clear the error. 220 bc_program_reset(p->prog); 221 222 // Jump if there is an error. 223 if (BC_ERR(vm->status)) BC_JMP; 224 } 225 226 #if BC_DEBUG 227 void 228 bc_parse_free(BcParse* p) 229 { 230 BC_SIG_ASSERT_LOCKED; 231 232 assert(p != NULL); 233 234 #if BC_ENABLED 235 if (BC_IS_BC) 236 { 237 bc_vec_free(&p->flags); 238 bc_vec_free(&p->exits); 239 bc_vec_free(&p->conds); 240 bc_vec_free(&p->ops); 241 bc_vec_free(&p->buf); 242 } 243 #endif // BC_ENABLED 244 245 bc_lex_free(&p->l); 246 } 247 #endif // BC_DEBUG 248 249 void 250 bc_parse_init(BcParse* p, BcProgram* prog, size_t func) 251 { 252 #if BC_ENABLED 253 uint16_t flag = 0; 254 #endif // BC_ENABLED 255 256 BC_SIG_ASSERT_LOCKED; 257 258 assert(p != NULL && prog != NULL); 259 260 #if BC_ENABLED 261 if (BC_IS_BC) 262 { 263 // We always want at least one flag set on the flags stack. 264 bc_vec_init(&p->flags, sizeof(uint16_t), BC_DTOR_NONE); 265 bc_vec_push(&p->flags, &flag); 266 267 bc_vec_init(&p->exits, sizeof(BcInstPtr), BC_DTOR_NONE); 268 bc_vec_init(&p->conds, sizeof(size_t), BC_DTOR_NONE); 269 bc_vec_init(&p->ops, sizeof(BcLexType), BC_DTOR_NONE); 270 bc_vec_init(&p->buf, sizeof(char), BC_DTOR_NONE); 271 272 p->auto_part = false; 273 } 274 #endif // BC_ENABLED 275 276 bc_lex_init(&p->l); 277 278 // Set up the function. 279 p->prog = prog; 280 bc_parse_updateFunc(p, func); 281 } 282