| 1 | /* |
| 2 | * filter-visitor-generate-bytecode.c |
| 3 | * |
| 4 | * LTTng filter bytecode generation |
| 5 | * |
| 6 | * Copyright 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 7 | * |
| 8 | * SPDX-License-Identifier: LGPL-2.1-only |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | #include <stdlib.h> |
| 13 | #include <string.h> |
| 14 | #include <common/align.hpp> |
| 15 | #include <common/compat/errno.hpp> |
| 16 | #include <common/compat/string.hpp> |
| 17 | |
| 18 | #include "common/align.hpp" |
| 19 | #include "common/bytecode/bytecode.hpp" |
| 20 | #include "common/compat/string.hpp" |
| 21 | #include "common/macros.hpp" |
| 22 | #include "common/string-utils/string-utils.hpp" |
| 23 | #include "filter-ast.hpp" |
| 24 | #include "filter-ir.hpp" |
| 25 | |
| 26 | static |
| 27 | int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx, |
| 28 | struct ir_op *node); |
| 29 | |
| 30 | static |
| 31 | int bytecode_patch(struct lttng_bytecode_alloc **fb, |
| 32 | const void *data, |
| 33 | uint16_t offset, |
| 34 | uint32_t len) |
| 35 | { |
| 36 | if (offset >= (*fb)->b.len) { |
| 37 | return -EINVAL; |
| 38 | } |
| 39 | memcpy(&(*fb)->b.data[offset], data, len); |
| 40 | return 0; |
| 41 | } |
| 42 | |
| 43 | static |
| 44 | int visit_node_root(struct filter_parser_ctx *ctx, struct ir_op *node) |
| 45 | { |
| 46 | int ret; |
| 47 | struct return_op insn; |
| 48 | |
| 49 | /* Visit child */ |
| 50 | ret = recursive_visit_gen_bytecode(ctx, node->u.root.child); |
| 51 | if (ret) |
| 52 | return ret; |
| 53 | |
| 54 | /* Generate end of bytecode instruction */ |
| 55 | insn.op = BYTECODE_OP_RETURN; |
| 56 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); |
| 57 | } |
| 58 | |
| 59 | /* |
| 60 | * 1: match |
| 61 | * 0: no match |
| 62 | * < 0: error |
| 63 | */ |
| 64 | static |
| 65 | int load_expression_legacy_match(const struct ir_load_expression *exp, |
| 66 | enum bytecode_op *op_type, |
| 67 | char **symbol) |
| 68 | { |
| 69 | const struct ir_load_expression_op *op; |
| 70 | bool need_dot = false; |
| 71 | |
| 72 | op = exp->child; |
| 73 | switch (op->type) { |
| 74 | case IR_LOAD_EXPRESSION_GET_CONTEXT_ROOT: |
| 75 | *op_type = BYTECODE_OP_GET_CONTEXT_REF; |
| 76 | if (strutils_append_str(symbol, "$ctx.")) { |
| 77 | return -ENOMEM; |
| 78 | } |
| 79 | need_dot = false; |
| 80 | break; |
| 81 | case IR_LOAD_EXPRESSION_GET_APP_CONTEXT_ROOT: |
| 82 | *op_type = BYTECODE_OP_GET_CONTEXT_REF; |
| 83 | if (strutils_append_str(symbol, "$app.")) { |
| 84 | return -ENOMEM; |
| 85 | } |
| 86 | need_dot = false; |
| 87 | break; |
| 88 | case IR_LOAD_EXPRESSION_GET_PAYLOAD_ROOT: |
| 89 | *op_type = BYTECODE_OP_LOAD_FIELD_REF; |
| 90 | need_dot = false; |
| 91 | break; |
| 92 | |
| 93 | case IR_LOAD_EXPRESSION_GET_SYMBOL: |
| 94 | case IR_LOAD_EXPRESSION_GET_INDEX: |
| 95 | case IR_LOAD_EXPRESSION_LOAD_FIELD: |
| 96 | default: |
| 97 | return 0; /* no match */ |
| 98 | } |
| 99 | |
| 100 | for (;;) { |
| 101 | op = op->next; |
| 102 | if (!op) { |
| 103 | return 0; /* no match */ |
| 104 | } |
| 105 | switch (op->type) { |
| 106 | case IR_LOAD_EXPRESSION_LOAD_FIELD: |
| 107 | goto end; |
| 108 | case IR_LOAD_EXPRESSION_GET_SYMBOL: |
| 109 | if (need_dot && strutils_append_str(symbol, ".")) { |
| 110 | return -ENOMEM; |
| 111 | } |
| 112 | if (strutils_append_str(symbol, op->u.symbol)) { |
| 113 | return -ENOMEM; |
| 114 | } |
| 115 | break; |
| 116 | default: |
| 117 | return 0; /* no match */ |
| 118 | } |
| 119 | need_dot = true; |
| 120 | } |
| 121 | end: |
| 122 | return 1; /* Legacy match */ |
| 123 | } |
| 124 | |
| 125 | /* |
| 126 | * 1: legacy match |
| 127 | * 0: no legacy match |
| 128 | * < 0: error |
| 129 | */ |
| 130 | static |
| 131 | int visit_node_load_expression_legacy(struct filter_parser_ctx *ctx, |
| 132 | const struct ir_load_expression *exp, |
| 133 | const struct ir_load_expression_op *op) |
| 134 | { |
| 135 | struct load_op *insn = NULL; |
| 136 | uint32_t insn_len = sizeof(struct load_op) |
| 137 | + sizeof(struct field_ref); |
| 138 | struct field_ref ref_offset; |
| 139 | uint32_t reloc_offset_u32; |
| 140 | uint16_t reloc_offset; |
| 141 | enum bytecode_op op_type; |
| 142 | char *symbol = NULL; |
| 143 | int ret; |
| 144 | |
| 145 | ret = load_expression_legacy_match(exp, &op_type, &symbol); |
| 146 | if (ret <= 0) { |
| 147 | goto end; |
| 148 | } |
| 149 | insn = (load_op *) calloc(insn_len, 1); |
| 150 | if (!insn) { |
| 151 | ret = -ENOMEM; |
| 152 | goto end; |
| 153 | } |
| 154 | insn->op = op_type; |
| 155 | ref_offset.offset = (uint16_t) -1U; |
| 156 | memcpy(insn->data, &ref_offset, sizeof(ref_offset)); |
| 157 | /* reloc_offset points to struct load_op */ |
| 158 | reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b); |
| 159 | if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) { |
| 160 | ret = -EINVAL; |
| 161 | goto end; |
| 162 | } |
| 163 | reloc_offset = (uint16_t) reloc_offset_u32; |
| 164 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
| 165 | if (ret) { |
| 166 | goto end; |
| 167 | } |
| 168 | /* append reloc */ |
| 169 | ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset, |
| 170 | 1, sizeof(reloc_offset)); |
| 171 | if (ret) { |
| 172 | goto end; |
| 173 | } |
| 174 | ret = bytecode_push(&ctx->bytecode_reloc, symbol, |
| 175 | 1, strlen(symbol) + 1); |
| 176 | if (ret) { |
| 177 | goto end; |
| 178 | } |
| 179 | ret = 1; /* legacy */ |
| 180 | end: |
| 181 | free(insn); |
| 182 | free(symbol); |
| 183 | return ret; |
| 184 | } |
| 185 | |
| 186 | static |
| 187 | int visit_node_load_expression(struct filter_parser_ctx *ctx, |
| 188 | const struct ir_op *node) |
| 189 | { |
| 190 | struct ir_load_expression *exp; |
| 191 | struct ir_load_expression_op *op; |
| 192 | int ret; |
| 193 | |
| 194 | exp = node->u.load.u.expression; |
| 195 | if (!exp) { |
| 196 | return -EINVAL; |
| 197 | } |
| 198 | op = exp->child; |
| 199 | if (!op) { |
| 200 | return -EINVAL; |
| 201 | } |
| 202 | |
| 203 | /* |
| 204 | * TODO: if we remove legacy load for application contexts, we |
| 205 | * need to update session bytecode parser as well. |
| 206 | */ |
| 207 | ret = visit_node_load_expression_legacy(ctx, exp, op); |
| 208 | if (ret < 0) { |
| 209 | return ret; |
| 210 | } |
| 211 | if (ret > 0) { |
| 212 | return 0; /* legacy */ |
| 213 | } |
| 214 | |
| 215 | for (; op != NULL; op = op->next) { |
| 216 | switch (op->type) { |
| 217 | case IR_LOAD_EXPRESSION_GET_CONTEXT_ROOT: |
| 218 | { |
| 219 | ret = bytecode_push_get_context_root(&ctx->bytecode); |
| 220 | |
| 221 | if (ret) { |
| 222 | return ret; |
| 223 | } |
| 224 | |
| 225 | break; |
| 226 | } |
| 227 | case IR_LOAD_EXPRESSION_GET_APP_CONTEXT_ROOT: |
| 228 | { |
| 229 | ret = bytecode_push_get_app_context_root( |
| 230 | &ctx->bytecode); |
| 231 | |
| 232 | if (ret) { |
| 233 | return ret; |
| 234 | } |
| 235 | |
| 236 | break; |
| 237 | } |
| 238 | case IR_LOAD_EXPRESSION_GET_PAYLOAD_ROOT: |
| 239 | { |
| 240 | ret = bytecode_push_get_payload_root(&ctx->bytecode); |
| 241 | |
| 242 | if (ret) { |
| 243 | return ret; |
| 244 | } |
| 245 | |
| 246 | break; |
| 247 | } |
| 248 | case IR_LOAD_EXPRESSION_GET_SYMBOL: |
| 249 | { |
| 250 | ret = bytecode_push_get_symbol(&ctx->bytecode, |
| 251 | &ctx->bytecode_reloc, op->u.symbol); |
| 252 | |
| 253 | if (ret) { |
| 254 | return ret; |
| 255 | } |
| 256 | |
| 257 | break; |
| 258 | } |
| 259 | case IR_LOAD_EXPRESSION_GET_INDEX: |
| 260 | { |
| 261 | ret = bytecode_push_get_index_u64( |
| 262 | &ctx->bytecode, op->u.index); |
| 263 | |
| 264 | if (ret) { |
| 265 | return ret; |
| 266 | } |
| 267 | |
| 268 | break; |
| 269 | } |
| 270 | case IR_LOAD_EXPRESSION_LOAD_FIELD: |
| 271 | { |
| 272 | struct load_op *insn; |
| 273 | uint32_t insn_len = sizeof(struct load_op); |
| 274 | |
| 275 | insn = (load_op *) calloc(insn_len, 1); |
| 276 | if (!insn) |
| 277 | return -ENOMEM; |
| 278 | insn->op = BYTECODE_OP_LOAD_FIELD; |
| 279 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
| 280 | free(insn); |
| 281 | if (ret) { |
| 282 | return ret; |
| 283 | } |
| 284 | break; |
| 285 | } |
| 286 | } |
| 287 | } |
| 288 | return 0; |
| 289 | } |
| 290 | |
| 291 | static |
| 292 | int visit_node_load(struct filter_parser_ctx *ctx, struct ir_op *node) |
| 293 | { |
| 294 | int ret; |
| 295 | |
| 296 | switch (node->data_type) { |
| 297 | case IR_DATA_UNKNOWN: |
| 298 | default: |
| 299 | fprintf(stderr, "[error] Unknown data type in %s\n", |
| 300 | __func__); |
| 301 | return -EINVAL; |
| 302 | |
| 303 | case IR_DATA_STRING: |
| 304 | { |
| 305 | struct load_op *insn; |
| 306 | uint32_t insn_len = sizeof(struct load_op) |
| 307 | + strlen(node->u.load.u.string.value) + 1; |
| 308 | |
| 309 | insn = (load_op *) calloc(insn_len, 1); |
| 310 | if (!insn) |
| 311 | return -ENOMEM; |
| 312 | |
| 313 | switch (node->u.load.u.string.type) { |
| 314 | case IR_LOAD_STRING_TYPE_GLOB_STAR: |
| 315 | /* |
| 316 | * We explicitly tell the interpreter here that |
| 317 | * this load is a full star globbing pattern so |
| 318 | * that the appropriate matching function can be |
| 319 | * called. Also, see comment below. |
| 320 | */ |
| 321 | insn->op = BYTECODE_OP_LOAD_STAR_GLOB_STRING; |
| 322 | break; |
| 323 | default: |
| 324 | /* |
| 325 | * This is the "legacy" string, which includes |
| 326 | * star globbing patterns with a star only at |
| 327 | * the end. Both "plain" and "star at the end" |
| 328 | * literal strings are handled at the same place |
| 329 | * by the tracer's filter bytecode interpreter, |
| 330 | * whereas full star globbing patterns (stars |
| 331 | * can be anywhere in the string) is a special |
| 332 | * case. |
| 333 | */ |
| 334 | insn->op = BYTECODE_OP_LOAD_STRING; |
| 335 | break; |
| 336 | } |
| 337 | |
| 338 | strcpy(insn->data, node->u.load.u.string.value); |
| 339 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
| 340 | free(insn); |
| 341 | return ret; |
| 342 | } |
| 343 | case IR_DATA_NUMERIC: |
| 344 | { |
| 345 | struct load_op *insn; |
| 346 | uint32_t insn_len = sizeof(struct load_op) |
| 347 | + sizeof(struct literal_numeric); |
| 348 | |
| 349 | insn = (load_op *) calloc(insn_len, 1); |
| 350 | if (!insn) |
| 351 | return -ENOMEM; |
| 352 | insn->op = BYTECODE_OP_LOAD_S64; |
| 353 | memcpy(insn->data, &node->u.load.u.num, sizeof(int64_t)); |
| 354 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
| 355 | free(insn); |
| 356 | return ret; |
| 357 | } |
| 358 | case IR_DATA_FLOAT: |
| 359 | { |
| 360 | struct load_op *insn; |
| 361 | uint32_t insn_len = sizeof(struct load_op) |
| 362 | + sizeof(struct literal_double); |
| 363 | |
| 364 | insn = (load_op *) calloc(insn_len, 1); |
| 365 | if (!insn) |
| 366 | return -ENOMEM; |
| 367 | insn->op = BYTECODE_OP_LOAD_DOUBLE; |
| 368 | memcpy(insn->data, &node->u.load.u.flt, sizeof(double)); |
| 369 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
| 370 | free(insn); |
| 371 | return ret; |
| 372 | } |
| 373 | case IR_DATA_EXPRESSION: |
| 374 | return visit_node_load_expression(ctx, node); |
| 375 | } |
| 376 | } |
| 377 | |
| 378 | static |
| 379 | int visit_node_unary(struct filter_parser_ctx *ctx, struct ir_op *node) |
| 380 | { |
| 381 | int ret; |
| 382 | struct unary_op insn; |
| 383 | |
| 384 | /* Visit child */ |
| 385 | ret = recursive_visit_gen_bytecode(ctx, node->u.unary.child); |
| 386 | if (ret) |
| 387 | return ret; |
| 388 | |
| 389 | /* Generate end of bytecode instruction */ |
| 390 | switch (node->u.unary.type) { |
| 391 | case AST_UNARY_UNKNOWN: |
| 392 | default: |
| 393 | fprintf(stderr, "[error] Unknown unary node type in %s\n", |
| 394 | __func__); |
| 395 | return -EINVAL; |
| 396 | case AST_UNARY_PLUS: |
| 397 | /* Nothing to do. */ |
| 398 | return 0; |
| 399 | case AST_UNARY_MINUS: |
| 400 | insn.op = BYTECODE_OP_UNARY_MINUS; |
| 401 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); |
| 402 | case AST_UNARY_NOT: |
| 403 | insn.op = BYTECODE_OP_UNARY_NOT; |
| 404 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); |
| 405 | case AST_UNARY_BIT_NOT: |
| 406 | insn.op = BYTECODE_OP_UNARY_BIT_NOT; |
| 407 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); |
| 408 | } |
| 409 | } |
| 410 | |
| 411 | /* |
| 412 | * Binary comparator nesting is disallowed. This allows fitting into |
| 413 | * only 2 registers. |
| 414 | */ |
| 415 | static |
| 416 | int visit_node_binary(struct filter_parser_ctx *ctx, struct ir_op *node) |
| 417 | { |
| 418 | int ret; |
| 419 | struct binary_op insn; |
| 420 | |
| 421 | /* Visit child */ |
| 422 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left); |
| 423 | if (ret) |
| 424 | return ret; |
| 425 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right); |
| 426 | if (ret) |
| 427 | return ret; |
| 428 | |
| 429 | switch (node->u.binary.type) { |
| 430 | case AST_OP_UNKNOWN: |
| 431 | default: |
| 432 | fprintf(stderr, "[error] Unknown unary node type in %s\n", |
| 433 | __func__); |
| 434 | return -EINVAL; |
| 435 | |
| 436 | case AST_OP_AND: |
| 437 | case AST_OP_OR: |
| 438 | fprintf(stderr, "[error] Unexpected logical node type in %s\n", |
| 439 | __func__); |
| 440 | return -EINVAL; |
| 441 | |
| 442 | case AST_OP_MUL: |
| 443 | insn.op = BYTECODE_OP_MUL; |
| 444 | break; |
| 445 | case AST_OP_DIV: |
| 446 | insn.op = BYTECODE_OP_DIV; |
| 447 | break; |
| 448 | case AST_OP_MOD: |
| 449 | insn.op = BYTECODE_OP_MOD; |
| 450 | break; |
| 451 | case AST_OP_PLUS: |
| 452 | insn.op = BYTECODE_OP_PLUS; |
| 453 | break; |
| 454 | case AST_OP_MINUS: |
| 455 | insn.op = BYTECODE_OP_MINUS; |
| 456 | break; |
| 457 | case AST_OP_BIT_RSHIFT: |
| 458 | insn.op = BYTECODE_OP_BIT_RSHIFT; |
| 459 | break; |
| 460 | case AST_OP_BIT_LSHIFT: |
| 461 | insn.op = BYTECODE_OP_BIT_LSHIFT; |
| 462 | break; |
| 463 | case AST_OP_BIT_AND: |
| 464 | insn.op = BYTECODE_OP_BIT_AND; |
| 465 | break; |
| 466 | case AST_OP_BIT_OR: |
| 467 | insn.op = BYTECODE_OP_BIT_OR; |
| 468 | break; |
| 469 | case AST_OP_BIT_XOR: |
| 470 | insn.op = BYTECODE_OP_BIT_XOR; |
| 471 | break; |
| 472 | |
| 473 | case AST_OP_EQ: |
| 474 | insn.op = BYTECODE_OP_EQ; |
| 475 | break; |
| 476 | case AST_OP_NE: |
| 477 | insn.op = BYTECODE_OP_NE; |
| 478 | break; |
| 479 | case AST_OP_GT: |
| 480 | insn.op = BYTECODE_OP_GT; |
| 481 | break; |
| 482 | case AST_OP_LT: |
| 483 | insn.op = BYTECODE_OP_LT; |
| 484 | break; |
| 485 | case AST_OP_GE: |
| 486 | insn.op = BYTECODE_OP_GE; |
| 487 | break; |
| 488 | case AST_OP_LE: |
| 489 | insn.op = BYTECODE_OP_LE; |
| 490 | break; |
| 491 | } |
| 492 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); |
| 493 | } |
| 494 | |
| 495 | /* |
| 496 | * A logical op always return a s64 (1 or 0). |
| 497 | */ |
| 498 | static |
| 499 | int visit_node_logical(struct filter_parser_ctx *ctx, struct ir_op *node) |
| 500 | { |
| 501 | int ret; |
| 502 | struct logical_op insn; |
| 503 | uint16_t skip_offset_loc; |
| 504 | uint16_t target_loc; |
| 505 | |
| 506 | /* Visit left child */ |
| 507 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left); |
| 508 | if (ret) |
| 509 | return ret; |
| 510 | /* Cast to s64 if float or field ref */ |
| 511 | if ((node->u.binary.left->data_type == IR_DATA_FIELD_REF |
| 512 | || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF |
| 513 | || node->u.binary.left->data_type == IR_DATA_EXPRESSION) |
| 514 | || node->u.binary.left->data_type == IR_DATA_FLOAT) { |
| 515 | struct cast_op cast_insn; |
| 516 | |
| 517 | if (node->u.binary.left->data_type == IR_DATA_FIELD_REF |
| 518 | || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF |
| 519 | || node->u.binary.left->data_type == IR_DATA_EXPRESSION) { |
| 520 | cast_insn.op = BYTECODE_OP_CAST_TO_S64; |
| 521 | } else { |
| 522 | cast_insn.op = BYTECODE_OP_CAST_DOUBLE_TO_S64; |
| 523 | } |
| 524 | ret = bytecode_push(&ctx->bytecode, &cast_insn, |
| 525 | 1, sizeof(cast_insn)); |
| 526 | if (ret) |
| 527 | return ret; |
| 528 | } |
| 529 | switch (node->u.logical.type) { |
| 530 | default: |
| 531 | fprintf(stderr, "[error] Unknown node type in %s\n", |
| 532 | __func__); |
| 533 | return -EINVAL; |
| 534 | |
| 535 | case AST_OP_AND: |
| 536 | insn.op = BYTECODE_OP_AND; |
| 537 | break; |
| 538 | case AST_OP_OR: |
| 539 | insn.op = BYTECODE_OP_OR; |
| 540 | break; |
| 541 | } |
| 542 | insn.skip_offset = (uint16_t) -1UL; /* Temporary */ |
| 543 | ret = bytecode_push_logical(&ctx->bytecode, &insn, 1, sizeof(insn), |
| 544 | &skip_offset_loc); |
| 545 | if (ret) |
| 546 | return ret; |
| 547 | /* Visit right child */ |
| 548 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right); |
| 549 | if (ret) |
| 550 | return ret; |
| 551 | /* Cast to s64 if float or field ref */ |
| 552 | if ((node->u.binary.right->data_type == IR_DATA_FIELD_REF |
| 553 | || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF |
| 554 | || node->u.binary.right->data_type == IR_DATA_EXPRESSION) |
| 555 | || node->u.binary.right->data_type == IR_DATA_FLOAT) { |
| 556 | struct cast_op cast_insn; |
| 557 | |
| 558 | if (node->u.binary.right->data_type == IR_DATA_FIELD_REF |
| 559 | || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF |
| 560 | || node->u.binary.right->data_type == IR_DATA_EXPRESSION) { |
| 561 | cast_insn.op = BYTECODE_OP_CAST_TO_S64; |
| 562 | } else { |
| 563 | cast_insn.op = BYTECODE_OP_CAST_DOUBLE_TO_S64; |
| 564 | } |
| 565 | ret = bytecode_push(&ctx->bytecode, &cast_insn, |
| 566 | 1, sizeof(cast_insn)); |
| 567 | if (ret) |
| 568 | return ret; |
| 569 | } |
| 570 | /* We now know where the logical op can skip. */ |
| 571 | target_loc = (uint16_t) bytecode_get_len(&ctx->bytecode->b); |
| 572 | ret = bytecode_patch(&ctx->bytecode, |
| 573 | &target_loc, /* Offset to jump to */ |
| 574 | skip_offset_loc, /* Where to patch */ |
| 575 | sizeof(uint16_t)); |
| 576 | return ret; |
| 577 | } |
| 578 | |
| 579 | /* |
| 580 | * Postorder traversal of the tree. We need the children result before |
| 581 | * we can evaluate the parent. |
| 582 | */ |
| 583 | static |
| 584 | int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx, |
| 585 | struct ir_op *node) |
| 586 | { |
| 587 | switch (node->op) { |
| 588 | case IR_OP_UNKNOWN: |
| 589 | default: |
| 590 | fprintf(stderr, "[error] Unknown node type in %s\n", |
| 591 | __func__); |
| 592 | return -EINVAL; |
| 593 | |
| 594 | case IR_OP_ROOT: |
| 595 | return visit_node_root(ctx, node); |
| 596 | case IR_OP_LOAD: |
| 597 | return visit_node_load(ctx, node); |
| 598 | case IR_OP_UNARY: |
| 599 | return visit_node_unary(ctx, node); |
| 600 | case IR_OP_BINARY: |
| 601 | return visit_node_binary(ctx, node); |
| 602 | case IR_OP_LOGICAL: |
| 603 | return visit_node_logical(ctx, node); |
| 604 | } |
| 605 | } |
| 606 | |
| 607 | void filter_bytecode_free(struct filter_parser_ctx *ctx) |
| 608 | { |
| 609 | if (!ctx) { |
| 610 | return; |
| 611 | } |
| 612 | |
| 613 | if (ctx->bytecode) { |
| 614 | free(ctx->bytecode); |
| 615 | ctx->bytecode = NULL; |
| 616 | } |
| 617 | |
| 618 | if (ctx->bytecode_reloc) { |
| 619 | free(ctx->bytecode_reloc); |
| 620 | ctx->bytecode_reloc = NULL; |
| 621 | } |
| 622 | } |
| 623 | |
| 624 | int filter_visitor_bytecode_generate(struct filter_parser_ctx *ctx) |
| 625 | { |
| 626 | int ret; |
| 627 | |
| 628 | ret = bytecode_init(&ctx->bytecode); |
| 629 | if (ret) |
| 630 | return ret; |
| 631 | ret = bytecode_init(&ctx->bytecode_reloc); |
| 632 | if (ret) |
| 633 | goto error; |
| 634 | ret = recursive_visit_gen_bytecode(ctx, ctx->ir_root); |
| 635 | if (ret) |
| 636 | goto error; |
| 637 | |
| 638 | /* Finally, append symbol table to bytecode */ |
| 639 | ctx->bytecode->b.reloc_table_offset = bytecode_get_len(&ctx->bytecode->b); |
| 640 | return bytecode_push(&ctx->bytecode, ctx->bytecode_reloc->b.data, |
| 641 | 1, bytecode_get_len(&ctx->bytecode_reloc->b)); |
| 642 | |
| 643 | error: |
| 644 | filter_bytecode_free(ctx); |
| 645 | return ret; |
| 646 | } |