+++ /dev/null
-/*
- * filter-visitor-generate-bytecode.c
- *
- * LTTng filter bytecode generation
- *
- * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License, version 2.1 only,
- * as published by the Free Software Foundation.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this library; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include "align.h"
-#include "filter-bytecode.h"
-#include "filter-ir.h"
-#include "filter-ast.h"
-
-#ifndef max_t
-#define max_t(type, a, b) ((type) ((a) > (b) ? (a) : (b)))
-#endif
-
-//#define INIT_ALLOC_SIZE PAGE_SIZE
-#define INIT_ALLOC_SIZE 4
-
-static
-int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
- struct ir_op *node);
-
-static
-int bytecode_init(struct lttng_filter_bytecode_alloc **fb)
-{
- *fb = calloc(sizeof(struct lttng_filter_bytecode_alloc) + INIT_ALLOC_SIZE, 1);
- if (!*fb) {
- return -ENOMEM;
- } else {
- (*fb)->alloc_len = INIT_ALLOC_SIZE;
- return 0;
- }
-}
-
-static
-int32_t bytecode_reserve(struct lttng_filter_bytecode_alloc **fb, uint32_t align, uint32_t len)
-{
- int32_t ret;
- uint32_t padding = offset_align((*fb)->b.len, align);
-
- if ((*fb)->b.len + padding + len > (*fb)->alloc_len) {
- uint32_t new_len =
- max_t(uint32_t, (*fb)->b.len + padding + len,
- (*fb)->alloc_len << 1);
- uint32_t old_len = (*fb)->alloc_len;
-
- if (new_len > 0xFFFF)
- return -EINVAL;
- *fb = realloc(*fb, sizeof(struct lttng_filter_bytecode_alloc) + new_len);
- if (!*fb)
- return -ENOMEM;
- memset(&(*fb)->b.data[old_len], 0, new_len - old_len);
- (*fb)->alloc_len = new_len;
- }
- (*fb)->b.len += padding;
- ret = (*fb)->b.len;
- (*fb)->b.len += len;
- return ret;
-}
-
-static
-int bytecode_push(struct lttng_filter_bytecode_alloc **fb, const void *data,
- uint32_t align, uint32_t len)
-{
- int32_t offset;
-
- offset = bytecode_reserve(fb, align, len);
- if (offset < 0)
- return offset;
- memcpy(&(*fb)->b.data[offset], data, len);
- return 0;
-}
-
-static
-int bytecode_push_logical(struct lttng_filter_bytecode_alloc **fb,
- struct logical_op *data,
- uint32_t align, uint32_t len,
- uint16_t *skip_offset)
-{
- int32_t offset;
-
- offset = bytecode_reserve(fb, align, len);
- if (offset < 0)
- return offset;
- memcpy(&(*fb)->b.data[offset], data, len);
- *skip_offset =
- (void *) &((struct logical_op *) &(*fb)->b.data[offset])->skip_offset
- - (void *) &(*fb)->b.data[0];
- return 0;
-}
-
-static
-int bytecode_patch(struct lttng_filter_bytecode_alloc **fb,
- const void *data,
- uint16_t offset,
- uint32_t len)
-{
- if (offset >= (*fb)->b.len) {
- return -EINVAL;
- }
- memcpy(&(*fb)->b.data[offset], data, len);
- return 0;
-}
-
-static
-int visit_node_root(struct filter_parser_ctx *ctx, struct ir_op *node)
-{
- int ret;
- struct return_op insn;
-
- /* Visit child */
- ret = recursive_visit_gen_bytecode(ctx, node->u.root.child);
- if (ret)
- return ret;
-
- /* Generate end of bytecode instruction */
- insn.op = FILTER_OP_RETURN;
- return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
-}
-
-static
-int visit_node_load(struct filter_parser_ctx *ctx, struct ir_op *node)
-{
- int ret;
-
- switch (node->data_type) {
- case IR_DATA_UNKNOWN:
- default:
- fprintf(stderr, "[error] Unknown data type in %s\n",
- __func__);
- return -EINVAL;
-
- case IR_DATA_STRING:
- {
- struct load_op *insn;
- uint32_t insn_len = sizeof(struct load_op)
- + strlen(node->u.load.u.string) + 1;
-
- insn = calloc(insn_len, 1);
- if (!insn)
- return -ENOMEM;
- insn->op = FILTER_OP_LOAD_STRING;
- strcpy(insn->data, node->u.load.u.string);
- ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
- free(insn);
- return ret;
- }
- case IR_DATA_NUMERIC:
- {
- struct load_op *insn;
- uint32_t insn_len = sizeof(struct load_op)
- + sizeof(struct literal_numeric);
-
- insn = calloc(insn_len, 1);
- if (!insn)
- return -ENOMEM;
- insn->op = FILTER_OP_LOAD_S64;
- *(int64_t *) insn->data = node->u.load.u.num;
- ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
- free(insn);
- return ret;
- }
- case IR_DATA_FLOAT:
- {
- struct load_op *insn;
- uint32_t insn_len = sizeof(struct load_op)
- + sizeof(struct literal_double);
-
- insn = calloc(insn_len, 1);
- if (!insn)
- return -ENOMEM;
- insn->op = FILTER_OP_LOAD_DOUBLE;
- *(double *) insn->data = node->u.load.u.flt;
- ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
- free(insn);
- return ret;
- }
- case IR_DATA_FIELD_REF:
- {
- struct load_op *insn;
- uint32_t insn_len = sizeof(struct load_op)
- + sizeof(struct field_ref);
- struct field_ref ref_offset;
- uint16_t reloc_offset;
-
- insn = calloc(insn_len, 1);
- if (!insn)
- return -ENOMEM;
- insn->op = FILTER_OP_LOAD_FIELD_REF;
- ref_offset.offset = (uint16_t) -1U;
- memcpy(insn->data, &ref_offset, sizeof(ref_offset));
- /* reloc_offset points to struct load_op */
- reloc_offset = bytecode_get_len(&ctx->bytecode->b);
- ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
- if (ret) {
- free(insn);
- return ret;
- }
- /* append reloc */
- ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset,
- 1, sizeof(reloc_offset));
- if (ret) {
- free(insn);
- return ret;
- }
- ret = bytecode_push(&ctx->bytecode_reloc, node->u.load.u.ref,
- 1, strlen(node->u.load.u.ref) + 1);
- free(insn);
- return ret;
- }
- }
-}
-
-static
-int visit_node_unary(struct filter_parser_ctx *ctx, struct ir_op *node)
-{
- int ret;
- struct unary_op insn;
-
- /* Visit child */
- ret = recursive_visit_gen_bytecode(ctx, node->u.unary.child);
- if (ret)
- return ret;
-
- /* Generate end of bytecode instruction */
- switch (node->u.unary.type) {
- case AST_UNARY_UNKNOWN:
- default:
- fprintf(stderr, "[error] Unknown unary node type in %s\n",
- __func__);
- return -EINVAL;
- case AST_UNARY_PLUS:
- /* Nothing to do. */
- return 0;
- case AST_UNARY_MINUS:
- insn.op = FILTER_OP_UNARY_MINUS;
- return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
- case AST_UNARY_NOT:
- insn.op = FILTER_OP_UNARY_NOT;
- return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
- }
-}
-
-/*
- * Binary comparator nesting is disallowed. This allows fitting into
- * only 2 registers.
- */
-static
-int visit_node_binary(struct filter_parser_ctx *ctx, struct ir_op *node)
-{
- int ret;
- struct binary_op insn;
-
- /* Visit child */
- ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left);
- if (ret)
- return ret;
- ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
- if (ret)
- return ret;
-
- switch (node->u.binary.type) {
- case AST_OP_UNKNOWN:
- default:
- fprintf(stderr, "[error] Unknown unary node type in %s\n",
- __func__);
- return -EINVAL;
-
- case AST_OP_AND:
- case AST_OP_OR:
- fprintf(stderr, "[error] Unexpected logical node type in %s\n",
- __func__);
- return -EINVAL;
-
- case AST_OP_MUL:
- insn.op = FILTER_OP_MUL;
- break;
- case AST_OP_DIV:
- insn.op = FILTER_OP_DIV;
- break;
- case AST_OP_MOD:
- insn.op = FILTER_OP_MOD;
- break;
- case AST_OP_PLUS:
- insn.op = FILTER_OP_PLUS;
- break;
- case AST_OP_MINUS:
- insn.op = FILTER_OP_MINUS;
- break;
- case AST_OP_RSHIFT:
- insn.op = FILTER_OP_RSHIFT;
- break;
- case AST_OP_LSHIFT:
- insn.op = FILTER_OP_LSHIFT;
- break;
- case AST_OP_BIN_AND:
- insn.op = FILTER_OP_BIN_AND;
- break;
- case AST_OP_BIN_OR:
- insn.op = FILTER_OP_BIN_OR;
- break;
- case AST_OP_BIN_XOR:
- insn.op = FILTER_OP_BIN_XOR;
- break;
-
- case AST_OP_EQ:
- insn.op = FILTER_OP_EQ;
- break;
- case AST_OP_NE:
- insn.op = FILTER_OP_NE;
- break;
- case AST_OP_GT:
- insn.op = FILTER_OP_GT;
- break;
- case AST_OP_LT:
- insn.op = FILTER_OP_LT;
- break;
- case AST_OP_GE:
- insn.op = FILTER_OP_GE;
- break;
- case AST_OP_LE:
- insn.op = FILTER_OP_LE;
- break;
- }
- return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
-}
-
-/*
- * A logical op always return a s64 (1 or 0).
- */
-static
-int visit_node_logical(struct filter_parser_ctx *ctx, struct ir_op *node)
-{
- int ret;
- struct logical_op insn;
- uint16_t skip_offset_loc;
- uint16_t target_loc;
-
- /* Visit left child */
- ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left);
- if (ret)
- return ret;
- /* Cast to s64 if float or field ref */
- if (node->u.binary.left->data_type == IR_DATA_FIELD_REF
- || node->u.binary.left->data_type == IR_DATA_FLOAT) {
- struct cast_op cast_insn;
-
- if (node->u.binary.left->data_type == IR_DATA_FIELD_REF) {
- cast_insn.op = FILTER_OP_CAST_TO_S64;
- } else {
- cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
- }
- ret = bytecode_push(&ctx->bytecode, &cast_insn,
- 1, sizeof(cast_insn));
- if (ret)
- return ret;
- }
- switch (node->u.logical.type) {
- default:
- fprintf(stderr, "[error] Unknown node type in %s\n",
- __func__);
- return -EINVAL;
-
- case AST_OP_AND:
- insn.op = FILTER_OP_AND;
- break;
- case AST_OP_OR:
- insn.op = FILTER_OP_OR;
- break;
- }
- insn.skip_offset = (uint16_t) -1UL; /* Temporary */
- ret = bytecode_push_logical(&ctx->bytecode, &insn, 1, sizeof(insn),
- &skip_offset_loc);
- if (ret)
- return ret;
- /* Visit right child */
- ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
- if (ret)
- return ret;
- /* Cast to s64 if float or field ref */
- if (node->u.binary.right->data_type == IR_DATA_FIELD_REF
- || node->u.binary.right->data_type == IR_DATA_FLOAT) {
- struct cast_op cast_insn;
-
- if (node->u.binary.right->data_type == IR_DATA_FIELD_REF) {
- cast_insn.op = FILTER_OP_CAST_TO_S64;
- } else {
- cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
- }
- ret = bytecode_push(&ctx->bytecode, &cast_insn,
- 1, sizeof(cast_insn));
- if (ret)
- return ret;
- }
- /* We now know where the logical op can skip. */
- target_loc = (uint16_t) bytecode_get_len(&ctx->bytecode->b);
- ret = bytecode_patch(&ctx->bytecode,
- &target_loc, /* Offset to jump to */
- skip_offset_loc, /* Where to patch */
- sizeof(uint16_t));
- return ret;
-}
-
-/*
- * Postorder traversal of the tree. We need the children result before
- * we can evaluate the parent.
- */
-static
-int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
- struct ir_op *node)
-{
- switch (node->op) {
- case IR_OP_UNKNOWN:
- default:
- fprintf(stderr, "[error] Unknown node type in %s\n",
- __func__);
- return -EINVAL;
-
- case IR_OP_ROOT:
- return visit_node_root(ctx, node);
- case IR_OP_LOAD:
- return visit_node_load(ctx, node);
- case IR_OP_UNARY:
- return visit_node_unary(ctx, node);
- case IR_OP_BINARY:
- return visit_node_binary(ctx, node);
- case IR_OP_LOGICAL:
- return visit_node_logical(ctx, node);
- }
-}
-
-void filter_bytecode_free(struct filter_parser_ctx *ctx)
-{
- free(ctx->bytecode);
- ctx->bytecode = NULL;
- free(ctx->bytecode_reloc);
- ctx->bytecode_reloc = NULL;
-}
-
-int filter_visitor_bytecode_generate(struct filter_parser_ctx *ctx)
-{
- int ret;
-
- ret = bytecode_init(&ctx->bytecode);
- if (ret)
- return ret;
- ret = bytecode_init(&ctx->bytecode_reloc);
- if (ret)
- goto error;
- ret = recursive_visit_gen_bytecode(ctx, ctx->ir_root);
- if (ret)
- goto error;
-
- /* Finally, append symbol table to bytecode */
- ctx->bytecode->b.reloc_table_offset = bytecode_get_len(&ctx->bytecode->b);
- return bytecode_push(&ctx->bytecode, ctx->bytecode_reloc->b.data,
- 1, bytecode_get_len(&ctx->bytecode_reloc->b));
-
-error:
- filter_bytecode_free(ctx);
- return ret;
-}
projects / lttng-tools.git / blobdiff