[lttng-tools.git] / src / lib / lttng-ctl / filter / filter-visitor-generate-bytecode.c

/*
 * 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 <common/align.h>
#include <common/compat/string.h>

#include "filter-bytecode.h"
#include "filter-ir.h"
#include "filter-ast.h"

#include <common/macros.h>

#ifndef max_t
#define max_t(type, a, b)	((type) ((a) > (b) ? (a) : (b)))
#endif

#define INIT_ALLOC_SIZE		4

static
int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
		struct ir_op *node);

static inline int get_count_order(unsigned int count)
{
	int order;

	order = lttng_fls(count) - 1;
	if (count & (count - 1))
		order++;
	return order;
}

static
int bytecode_init(struct lttng_filter_bytecode_alloc **fb)
{
	uint32_t alloc_len;

	alloc_len = sizeof(struct lttng_filter_bytecode_alloc) + INIT_ALLOC_SIZE;
	*fb = calloc(alloc_len, 1);
	if (!*fb) {
		return -ENOMEM;
	} else {
		(*fb)->alloc_len = alloc_len;
		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);
	uint32_t new_len = (*fb)->b.len + padding + len;
	uint32_t new_alloc_len = sizeof(struct lttng_filter_bytecode_alloc) + new_len;
	uint32_t old_alloc_len = (*fb)->alloc_len;

	if (new_len > LTTNG_FILTER_MAX_LEN)
		return -EINVAL;

	if (new_alloc_len > old_alloc_len) {
		struct lttng_filter_bytecode_alloc *newptr;

		new_alloc_len =
			max_t(uint32_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1);
		newptr = realloc(*fb, new_alloc_len);
		if (!newptr)
			return -ENOMEM;
		*fb = newptr;
		/* We zero directly the memory from start of allocation. */
		memset(&((char *) *fb)[old_alloc_len], 0, new_alloc_len - old_alloc_len);
		(*fb)->alloc_len = new_alloc_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_expression(struct filter_parser_ctx *ctx,
		struct ir_op *node)
{
	struct ir_load_expression *exp;
	struct ir_load_expression_op *op;

	exp = node->u.load.u.expression;
	if (!exp) {
		return -EINVAL;
	}
	op = exp->child;
	if (!op) {
		return -EINVAL;
	}
	for (; op != NULL; op = op->next) {
		switch (op->type) {
		case IR_LOAD_EXPRESSION_GET_CONTEXT_ROOT:
		{
			struct load_op *insn;
			uint32_t insn_len = sizeof(struct load_op);
			int ret;

			insn = calloc(insn_len, 1);
			if (!insn)
				return -ENOMEM;
			insn->op = FILTER_OP_GET_CONTEXT_ROOT;
			ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
			free(insn);
			if (ret) {
				return ret;
			}
			break;
		}
		case IR_LOAD_EXPRESSION_GET_APP_CONTEXT_ROOT:
		{
			struct load_op *insn;
			uint32_t insn_len = sizeof(struct load_op);
			int ret;

			insn = calloc(insn_len, 1);
			if (!insn)
				return -ENOMEM;
			insn->op = FILTER_OP_GET_APP_CONTEXT_ROOT;
			ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
			free(insn);
			if (ret) {
				return ret;
			}
			break;
		}
		case IR_LOAD_EXPRESSION_GET_PAYLOAD_ROOT:
		{
			struct load_op *insn;
			uint32_t insn_len = sizeof(struct load_op);
			int ret;

			insn = calloc(insn_len, 1);
			if (!insn)
				return -ENOMEM;
			insn->op = FILTER_OP_GET_PAYLOAD_ROOT;
			ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
			free(insn);
			if (ret) {
				return ret;
			}
			break;
		}
		case IR_LOAD_EXPRESSION_GET_SYMBOL:
		{
			struct load_op *insn;
			uint32_t insn_len = sizeof(struct load_op)
				+ sizeof(struct get_symbol);
			struct get_symbol symbol_offset;
			uint32_t reloc_offset_u32;
			uint16_t reloc_offset;
			uint32_t bytecode_reloc_offset_u32;
			int ret;

			insn = calloc(insn_len, 1);
			if (!insn)
				return -ENOMEM;
			insn->op = FILTER_OP_GET_SYMBOL;
			bytecode_reloc_offset_u32 =
				bytecode_get_len(&ctx->bytecode_reloc->b)
					+ sizeof(reloc_offset);
			symbol_offset.offset =
				(uint16_t) bytecode_reloc_offset_u32;
			memcpy(insn->data, &symbol_offset,
					sizeof(symbol_offset));
			/* reloc_offset points to struct load_op */
			reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b);
			if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
				free(insn);
				return -EINVAL;
			}
			reloc_offset = (uint16_t) reloc_offset_u32;
			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,
					op->u.symbol,
					1, strlen(op->u.symbol) + 1);
			free(insn);
			if (ret) {
				return ret;
			}
			break;
		}
		case IR_LOAD_EXPRESSION_GET_INDEX:
		{
			struct load_op *insn;
			uint32_t insn_len = sizeof(struct load_op)
				+ sizeof(struct get_index_u64);
			struct get_index_u64 index;
			int ret;

			insn = calloc(insn_len, 1);
			if (!insn)
				return -ENOMEM;
			insn->op = FILTER_OP_GET_INDEX_U64;
			index.index = op->u.index;
			memcpy(insn->data, &index, sizeof(index));
			ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
			free(insn);
			if (ret) {
				return ret;
			}
			break;
		}
		case IR_LOAD_EXPRESSION_LOAD_FIELD:
		{
			struct load_op *insn;
			uint32_t insn_len = sizeof(struct load_op);
			int ret;

			insn = calloc(insn_len, 1);
			if (!insn)
				return -ENOMEM;
			insn->op = FILTER_OP_LOAD_FIELD;
			ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
			free(insn);
			if (ret) {
				return ret;
			}
			break;
		}
		}
	}
	return 0;
}

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.value) + 1;

		insn = calloc(insn_len, 1);
		if (!insn)
			return -ENOMEM;

		switch (node->u.load.u.string.type) {
		case IR_LOAD_STRING_TYPE_GLOB_STAR:
			/*
			 * We explicitly tell the interpreter here that
			 * this load is a full star globbing pattern so
			 * that the appropriate matching function can be
			 * called. Also, see comment below.
			 */
			insn->op = FILTER_OP_LOAD_STAR_GLOB_STRING;
			break;
		default:
			/*
			 * This is the "legacy" string, which includes
			 * star globbing patterns with a star only at
			 * the end. Both "plain" and "star at the end"
			 * literal strings are handled at the same place
			 * by the tracer's filter bytecode interpreter,
			 * whereas full star globbing patterns (stars
			 * can be anywhere in the string) is a special
			 * case.
			 */
			insn->op = FILTER_OP_LOAD_STRING;
			break;
		}

		strcpy(insn->data, node->u.load.u.string.value);
		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;
		memcpy(insn->data, &node->u.load.u.num, sizeof(int64_t));
		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;
		memcpy(insn->data, &node->u.load.u.flt, sizeof(double));
		ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
		free(insn);
		return ret;
	}
#if 0
	case IR_DATA_FIELD_REF:	/* fall-through */
	case IR_DATA_GET_CONTEXT_REF:
	{
		struct load_op *insn;
		uint32_t insn_len = sizeof(struct load_op)
			+ sizeof(struct field_ref);
		struct field_ref ref_offset;
		uint32_t reloc_offset_u32;
		uint16_t reloc_offset;

		insn = calloc(insn_len, 1);
		if (!insn)
			return -ENOMEM;
		switch (node->data_type) {
		case IR_DATA_FIELD_REF:
			insn->op = FILTER_OP_LOAD_FIELD_REF;
			break;
		case IR_DATA_GET_CONTEXT_REF:
			insn->op = FILTER_OP_GET_CONTEXT_REF;
			break;
		default:
			free(insn);
			return -EINVAL;
		}
		ref_offset.offset = (uint16_t) -1U;
		memcpy(insn->data, &ref_offset, sizeof(ref_offset));
		/* reloc_offset points to struct load_op */
		reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b);
		if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
			free(insn);
			return -EINVAL;
		}
		reloc_offset = (uint16_t) reloc_offset_u32;
		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;
	}
#endif
	case IR_DATA_EXPRESSION:
		return visit_node_load_expression(ctx, node);
	}
}

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_BIT_AND:
		insn.op = FILTER_OP_BIT_AND;
		break;
	case AST_OP_BIT_OR:
		insn.op = FILTER_OP_BIT_OR;
		break;
	case AST_OP_BIT_XOR:
		insn.op = FILTER_OP_BIT_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_GET_CONTEXT_REF
				|| node->u.binary.left->data_type == IR_DATA_EXPRESSION)
			|| 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
				|| node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF
				|| node->u.binary.left->data_type == IR_DATA_EXPRESSION) {
			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_GET_CONTEXT_REF
				|| node->u.binary.right->data_type == IR_DATA_EXPRESSION)
			|| 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
				|| node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF
				|| node->u.binary.right->data_type == IR_DATA_EXPRESSION) {
			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);
	}
}

LTTNG_HIDDEN
void filter_bytecode_free(struct filter_parser_ctx *ctx)
{
	if (!ctx) {
		return;
	}

	if (ctx->bytecode) {
		free(ctx->bytecode);
		ctx->bytecode = NULL;
	}

	if (ctx->bytecode_reloc) {
		free(ctx->bytecode_reloc);
		ctx->bytecode_reloc = NULL;
	}
}

LTTNG_HIDDEN
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;
}
Commit	Line	Data
953192ba MD	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	* This library is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU Lesser General Public License, version 2.1 only,
	10	* as published by the Free Software Foundation.
	11	*
	12	* This library is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* Lesser General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU Lesser General Public License
	18	* along with this library; if not, write to the Free Software Foundation,
	19	* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	20	*/
	21
	22	#include <stdlib.h>
	23	#include <string.h>
	24	#include <errno.h>
46820c8b	25	#include <common/align.h>
afc5df03	26	#include <common/compat/string.h>
46820c8b	27
953192ba MD	28	#include "filter-bytecode.h"
	29	#include "filter-ir.h"
	30	#include "filter-ast.h"
	31
a187da1a DG	32	#include <common/macros.h>
a187da1a DG	33
953192ba MD	34	#ifndef max_t
	35	#define max_t(type, a, b) ((type) ((a) > (b) ? (a) : (b)))
	36	#endif
	37
953192ba MD	38	#define INIT_ALLOC_SIZE 4
	39
	40	static
	41	int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
	42	struct ir_op *node);
	43
01a204f0 CB	44	static inline int get_count_order(unsigned int count)
	45	{
	46	int order;
	47
afc5df03	48	order = lttng_fls(count) - 1;
01a204f0 CB	49	if (count & (count - 1))
	50	order++;
	51	return order;
	52	}
	53
953192ba	54	static
53a80697	55	int bytecode_init(struct lttng_filter_bytecode_alloc **fb)
953192ba	56	{
1029587a MD	57	uint32_t alloc_len;
	58
	59	alloc_len = sizeof(struct lttng_filter_bytecode_alloc) + INIT_ALLOC_SIZE;
	60	*fb = calloc(alloc_len, 1);
953192ba MD	61	if (!*fb) {
	62	return -ENOMEM;
	63	} else {
1029587a	64	(*fb)->alloc_len = alloc_len;
953192ba MD	65	return 0;
	66	}
	67	}
	68
	69	static
53a80697	70	int32_t bytecode_reserve(struct lttng_filter_bytecode_alloc **fb, uint32_t align, uint32_t len)
953192ba MD	71	{
	72	int32_t ret;
	73	uint32_t padding = offset_align((*fb)->b.len, align);
ec96a8f6	74	uint32_t new_len = (*fb)->b.len + padding + len;
1029587a	75	uint32_t new_alloc_len = sizeof(struct lttng_filter_bytecode_alloc) + new_len;
ec96a8f6	76	uint32_t old_alloc_len = (*fb)->alloc_len;
953192ba	77
ec96a8f6	78	if (new_len > LTTNG_FILTER_MAX_LEN)
5ddb0a08 CB	79	return -EINVAL;
5ddb0a08 CB	80
ec96a8f6	81	if (new_alloc_len > old_alloc_len) {
d0b96690 DG	82	struct lttng_filter_bytecode_alloc *newptr;
d0b96690 DG	83
ec96a8f6 MD	84	new_alloc_len =
ec96a8f6 MD	85	max_t(uint32_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1);
d0b96690 DG	86	newptr = realloc(*fb, new_alloc_len);
d0b96690 DG	87	if (!newptr)
953192ba	88	return -ENOMEM;
d0b96690	89	*fb = newptr;
1029587a	90	/* We zero directly the memory from start of allocation. */
ec96a8f6 MD	91	memset(&((char ) fb)[old_alloc_len], 0, new_alloc_len - old_alloc_len);
ec96a8f6 MD	92	(*fb)->alloc_len = new_alloc_len;
953192ba MD	93	}
	94	(*fb)->b.len += padding;
	95	ret = (*fb)->b.len;
	96	(*fb)->b.len += len;
	97	return ret;
	98	}
	99
	100	static
53a80697	101	int bytecode_push(struct lttng_filter_bytecode_alloc *fb, const void data,
953192ba MD	102	uint32_t align, uint32_t len)
	103	{
	104	int32_t offset;
	105
	106	offset = bytecode_reserve(fb, align, len);
	107	if (offset < 0)
	108	return offset;
	109	memcpy(&(*fb)->b.data[offset], data, len);
	110	return 0;
	111	}
	112
	113	static
53a80697	114	int bytecode_push_logical(struct lttng_filter_bytecode_alloc **fb,
953192ba MD	115	struct logical_op *data,
	116	uint32_t align, uint32_t len,
	117	uint16_t *skip_offset)
	118	{
	119	int32_t offset;
	120
	121	offset = bytecode_reserve(fb, align, len);
	122	if (offset < 0)
	123	return offset;
	124	memcpy(&(*fb)->b.data[offset], data, len);
	125	*skip_offset =
	126	(void ) &((struct logical_op ) &(*fb)->b.data[offset])->skip_offset
	127	- (void ) &(fb)->b.data[0];
	128	return 0;
	129	}
	130
	131	static
53a80697	132	int bytecode_patch(struct lttng_filter_bytecode_alloc **fb,
953192ba MD	133	const void *data,
	134	uint16_t offset,
	135	uint32_t len)
	136	{
	137	if (offset >= (*fb)->b.len) {
	138	return -EINVAL;
	139	}
	140	memcpy(&(*fb)->b.data[offset], data, len);
	141	return 0;
	142	}
	143
	144	static
	145	int visit_node_root(struct filter_parser_ctx ctx, struct ir_op node)
	146	{
	147	int ret;
	148	struct return_op insn;
	149
	150	/* Visit child */
	151	ret = recursive_visit_gen_bytecode(ctx, node->u.root.child);
	152	if (ret)
	153	return ret;
	154
	155	/* Generate end of bytecode instruction */
	156	insn.op = FILTER_OP_RETURN;
	157	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	158	}
	159
87942d06 MD	160	static
	161	int visit_node_load_expression(struct filter_parser_ctx *ctx,
	162	struct ir_op *node)
	163	{
	164	struct ir_load_expression *exp;
	165	struct ir_load_expression_op *op;
	166
	167	exp = node->u.load.u.expression;
	168	if (!exp) {
	169	return -EINVAL;
	170	}
	171	op = exp->child;
	172	if (!op) {
	173	return -EINVAL;
	174	}
	175	for (; op != NULL; op = op->next) {
	176	switch (op->type) {
	177	case IR_LOAD_EXPRESSION_GET_CONTEXT_ROOT:
	178	{
	179	struct load_op *insn;
	180	uint32_t insn_len = sizeof(struct load_op);
	181	int ret;
	182
	183	insn = calloc(insn_len, 1);
	184	if (!insn)
	185	return -ENOMEM;
	186	insn->op = FILTER_OP_GET_CONTEXT_ROOT;
	187	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	188	free(insn);
	189	if (ret) {
	190	return ret;
	191	}
	192	break;
	193	}
	194	case IR_LOAD_EXPRESSION_GET_APP_CONTEXT_ROOT:
	195	{
	196	struct load_op *insn;
	197	uint32_t insn_len = sizeof(struct load_op);
	198	int ret;
	199
	200	insn = calloc(insn_len, 1);
	201	if (!insn)
	202	return -ENOMEM;
	203	insn->op = FILTER_OP_GET_APP_CONTEXT_ROOT;
	204	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	205	free(insn);
	206	if (ret) {
	207	return ret;
	208	}
	209	break;
	210	}
	211	case IR_LOAD_EXPRESSION_GET_PAYLOAD_ROOT:
	212	{
	213	struct load_op *insn;
	214	uint32_t insn_len = sizeof(struct load_op);
	215	int ret;
	216
	217	insn = calloc(insn_len, 1);
	218	if (!insn)
	219	return -ENOMEM;
	220	insn->op = FILTER_OP_GET_PAYLOAD_ROOT;
	221	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	222	free(insn);
	223	if (ret) {
224	return ret;
225	}
226	break;
227	}
228	case IR_LOAD_EXPRESSION_GET_SYMBOL:
229	{
230	struct load_op *insn;
231	uint32_t insn_len = sizeof(struct load_op)
232	+ sizeof(struct get_symbol);
233	struct get_symbol symbol_offset;
234	uint32_t reloc_offset_u32;
235	uint16_t reloc_offset;
236	uint32_t bytecode_reloc_offset_u32;
237	int ret;
238
239	insn = calloc(insn_len, 1);
240	if (!insn)
241	return -ENOMEM;
242	insn->op = FILTER_OP_GET_SYMBOL;
243	bytecode_reloc_offset_u32 =
244	bytecode_get_len(&ctx->bytecode_reloc->b)
245	+ sizeof(reloc_offset);
246	symbol_offset.offset =
247	(uint16_t) bytecode_reloc_offset_u32;
248	memcpy(insn->data, &symbol_offset,
249	sizeof(symbol_offset));
250	/* reloc_offset points to struct load_op */
251	reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b);
252	if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
253	free(insn);
254	return -EINVAL;
255	}
256	reloc_offset = (uint16_t) reloc_offset_u32;
257	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
258	if (ret) {
259	free(insn);
260	return ret;
261	}
262	/* append reloc */
263	ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset,
264	1, sizeof(reloc_offset));
265	if (ret) {
266	free(insn);
267	return ret;
268	}
269	ret = bytecode_push(&ctx->bytecode_reloc,
270	op->u.symbol,
271	1, strlen(op->u.symbol) + 1);
272	free(insn);
273	if (ret) {
274	return ret;
275	}
276	break;
277	}
278	case IR_LOAD_EXPRESSION_GET_INDEX:
279	{
280	struct load_op *insn;
281	uint32_t insn_len = sizeof(struct load_op)
282	+ sizeof(struct get_index_u64);
283	struct get_index_u64 index;
284	int ret;
285
286	insn = calloc(insn_len, 1);
287	if (!insn)
288	return -ENOMEM;
289	insn->op = FILTER_OP_GET_INDEX_U64;
290	index.index = op->u.index;
291	memcpy(insn->data, &index, sizeof(index));
292	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
293	free(insn);
294	if (ret) {
295	return ret;
296	}
297	break;
298	}
299	case IR_LOAD_EXPRESSION_LOAD_FIELD:
300	{
301	struct load_op *insn;
302	uint32_t insn_len = sizeof(struct load_op);
303	int ret;
304
305	insn = calloc(insn_len, 1);
306	if (!insn)
307	return -ENOMEM;
308	insn->op = FILTER_OP_LOAD_FIELD;
309	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
310	free(insn);
311	if (ret) {
312	return ret;
313	}
314	break;
315	}
316	}
317	}
318	return 0;
319	}
320
953192ba MD	321	static
	322	int visit_node_load(struct filter_parser_ctx ctx, struct ir_op node)
	323	{
	324	int ret;
	325
	326	switch (node->data_type) {
	327	case IR_DATA_UNKNOWN:
	328	default:
	329	fprintf(stderr, "[error] Unknown data type in %s\n",
	330	__func__);
	331	return -EINVAL;
	332
	333	case IR_DATA_STRING:
	334	{
	335	struct load_op *insn;
	336	uint32_t insn_len = sizeof(struct load_op)
9f449915	337	+ strlen(node->u.load.u.string.value) + 1;
953192ba MD	338
	339	insn = calloc(insn_len, 1);
	340	if (!insn)
	341	return -ENOMEM;
9f449915 PP	342
	343	switch (node->u.load.u.string.type) {
	344	case IR_LOAD_STRING_TYPE_GLOB_STAR:
	345	/*
	346	* We explicitly tell the interpreter here that
	347	* this load is a full star globbing pattern so
	348	* that the appropriate matching function can be
	349	* called. Also, see comment below.
	350	*/
	351	insn->op = FILTER_OP_LOAD_STAR_GLOB_STRING;
	352	break;
	353	default:
	354	/*
	355	* This is the "legacy" string, which includes
	356	* star globbing patterns with a star only at
	357	* the end. Both "plain" and "star at the end"
	358	* literal strings are handled at the same place
	359	* by the tracer's filter bytecode interpreter,
	360	* whereas full star globbing patterns (stars
	361	* can be anywhere in the string) is a special
	362	* case.
	363	*/
	364	insn->op = FILTER_OP_LOAD_STRING;
	365	break;
	366	}
	367
	368	strcpy(insn->data, node->u.load.u.string.value);
953192ba MD	369	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	370	free(insn);
	371	return ret;
	372	}
	373	case IR_DATA_NUMERIC:
	374	{
	375	struct load_op *insn;
	376	uint32_t insn_len = sizeof(struct load_op)
	377	+ sizeof(struct literal_numeric);
	378
	379	insn = calloc(insn_len, 1);
	380	if (!insn)
	381	return -ENOMEM;
	382	insn->op = FILTER_OP_LOAD_S64;
58d494e4	383	memcpy(insn->data, &node->u.load.u.num, sizeof(int64_t));
953192ba MD	384	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	385	free(insn);
	386	return ret;
	387	}
e90d8561 MD	388	case IR_DATA_FLOAT:
	389	{
	390	struct load_op *insn;
	391	uint32_t insn_len = sizeof(struct load_op)
	392	+ sizeof(struct literal_double);
	393
	394	insn = calloc(insn_len, 1);
	395	if (!insn)
	396	return -ENOMEM;
	397	insn->op = FILTER_OP_LOAD_DOUBLE;
58d494e4	398	memcpy(insn->data, &node->u.load.u.flt, sizeof(double));
e90d8561 MD	399	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	400	free(insn);
	401	return ret;
	402	}
87942d06	403	#if 0
586dc72f MD	404	case IR_DATA_FIELD_REF: /* fall-through */
586dc72f MD	405	case IR_DATA_GET_CONTEXT_REF:
953192ba MD	406	{
	407	struct load_op *insn;
	408	uint32_t insn_len = sizeof(struct load_op)
	409	+ sizeof(struct field_ref);
	410	struct field_ref ref_offset;
ec96a8f6 MD	411	uint32_t reloc_offset_u32;
ec96a8f6 MD	412	uint16_t reloc_offset;
953192ba MD	413
	414	insn = calloc(insn_len, 1);
	415	if (!insn)
	416	return -ENOMEM;
5590fc2c	417	switch (node->data_type) {
586dc72f MD	418	case IR_DATA_FIELD_REF:
	419	insn->op = FILTER_OP_LOAD_FIELD_REF;
	420	break;
	421	case IR_DATA_GET_CONTEXT_REF:
	422	insn->op = FILTER_OP_GET_CONTEXT_REF;
	423	break;
	424	default:
3a68137c	425	free(insn);
586dc72f MD	426	return -EINVAL;
586dc72f MD	427	}
953192ba MD	428	ref_offset.offset = (uint16_t) -1U;
953192ba MD	429	memcpy(insn->data, &ref_offset, sizeof(ref_offset));
65775683	430	/* reloc_offset points to struct load_op */
ec96a8f6 MD	431	reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b);
	432	if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
	433	free(insn);
	434	return -EINVAL;
	435	}
	436	reloc_offset = (uint16_t) reloc_offset_u32;
953192ba MD	437	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	438	if (ret) {
	439	free(insn);
	440	return ret;
	441	}
	442	/* append reloc */
	443	ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset,
	444	1, sizeof(reloc_offset));
	445	if (ret) {
	446	free(insn);
	447	return ret;
	448	}
	449	ret = bytecode_push(&ctx->bytecode_reloc, node->u.load.u.ref,
	450	1, strlen(node->u.load.u.ref) + 1);
	451	free(insn);
	452	return ret;
	453	}
87942d06 MD	454	#endif
	455	case IR_DATA_EXPRESSION:
	456	return visit_node_load_expression(ctx, node);
953192ba MD	457	}
	458	}
	459
	460	static
	461	int visit_node_unary(struct filter_parser_ctx ctx, struct ir_op node)
	462	{
	463	int ret;
	464	struct unary_op insn;
	465
	466	/* Visit child */
	467	ret = recursive_visit_gen_bytecode(ctx, node->u.unary.child);
	468	if (ret)
	469	return ret;
	470
	471	/* Generate end of bytecode instruction */
	472	switch (node->u.unary.type) {
	473	case AST_UNARY_UNKNOWN:
	474	default:
	475	fprintf(stderr, "[error] Unknown unary node type in %s\n",
	476	__func__);
	477	return -EINVAL;
	478	case AST_UNARY_PLUS:
	479	/* Nothing to do. */
	480	return 0;
	481	case AST_UNARY_MINUS:
	482	insn.op = FILTER_OP_UNARY_MINUS;
953192ba MD	483	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	484	case AST_UNARY_NOT:
	485	insn.op = FILTER_OP_UNARY_NOT;
953192ba MD	486	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	487	}
	488	}
	489
	490	/*
	491	* Binary comparator nesting is disallowed. This allows fitting into
	492	* only 2 registers.
	493	*/
	494	static
	495	int visit_node_binary(struct filter_parser_ctx ctx, struct ir_op node)
	496	{
	497	int ret;
	498	struct binary_op insn;
	499
	500	/* Visit child */
	501	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left);
	502	if (ret)
	503	return ret;
	504	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
	505	if (ret)
	506	return ret;
	507
	508	switch (node->u.binary.type) {
	509	case AST_OP_UNKNOWN:
	510	default:
	511	fprintf(stderr, "[error] Unknown unary node type in %s\n",
	512	__func__);
	513	return -EINVAL;
	514
	515	case AST_OP_AND:
	516	case AST_OP_OR:
	517	fprintf(stderr, "[error] Unexpected logical node type in %s\n",
	518	__func__);
	519	return -EINVAL;
	520
	521	case AST_OP_MUL:
	522	insn.op = FILTER_OP_MUL;
	523	break;
	524	case AST_OP_DIV:
	525	insn.op = FILTER_OP_DIV;
	526	break;
	527	case AST_OP_MOD:
	528	insn.op = FILTER_OP_MOD;
	529	break;
	530	case AST_OP_PLUS:
	531	insn.op = FILTER_OP_PLUS;
	532	break;
	533	case AST_OP_MINUS:
	534	insn.op = FILTER_OP_MINUS;
	535	break;
	536	case AST_OP_RSHIFT:
	537	insn.op = FILTER_OP_RSHIFT;
	538	break;
	539	case AST_OP_LSHIFT:
	540	insn.op = FILTER_OP_LSHIFT;
	541	break;
87942d06 MD	542	case AST_OP_BIT_AND:
87942d06 MD	543	insn.op = FILTER_OP_BIT_AND;
953192ba	544	break;
87942d06 MD	545	case AST_OP_BIT_OR:
87942d06 MD	546	insn.op = FILTER_OP_BIT_OR;
953192ba	547	break;
87942d06 MD	548	case AST_OP_BIT_XOR:
87942d06 MD	549	insn.op = FILTER_OP_BIT_XOR;
953192ba MD	550	break;
	551
	552	case AST_OP_EQ:
	553	insn.op = FILTER_OP_EQ;
	554	break;
	555	case AST_OP_NE:
	556	insn.op = FILTER_OP_NE;
	557	break;
	558	case AST_OP_GT:
	559	insn.op = FILTER_OP_GT;
	560	break;
	561	case AST_OP_LT:
	562	insn.op = FILTER_OP_LT;
	563	break;
	564	case AST_OP_GE:
	565	insn.op = FILTER_OP_GE;
	566	break;
	567	case AST_OP_LE:
	568	insn.op = FILTER_OP_LE;
	569	break;
	570	}
	571	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	572	}
	573
8cf9540a MD	574	/*
	575	* A logical op always return a s64 (1 or 0).
	576	*/
953192ba MD	577	static
	578	int visit_node_logical(struct filter_parser_ctx ctx, struct ir_op node)
	579	{
	580	int ret;
	581	struct logical_op insn;
	582	uint16_t skip_offset_loc;
	583	uint16_t target_loc;
	584
	585	/* Visit left child */
	586	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left);
	587	if (ret)
	588	return ret;
8cf9540a	589	/* Cast to s64 if float or field ref */
586dc72f	590	if ((node->u.binary.left->data_type == IR_DATA_FIELD_REF
5590fc2c	591	\|\| node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF
87942d06	592	\|\| node->u.binary.left->data_type == IR_DATA_EXPRESSION)
8cf9540a MD	593	\|\| node->u.binary.left->data_type == IR_DATA_FLOAT) {
	594	struct cast_op cast_insn;
	595
586dc72f	596	if (node->u.binary.left->data_type == IR_DATA_FIELD_REF
5590fc2c	597	\|\| node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF
87942d06	598	\|\| node->u.binary.left->data_type == IR_DATA_EXPRESSION) {
29fefef8 MD	599	cast_insn.op = FILTER_OP_CAST_TO_S64;
	600	} else {
	601	cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
	602	}
8cf9540a MD	603	ret = bytecode_push(&ctx->bytecode, &cast_insn,
	604	1, sizeof(cast_insn));
	605	if (ret)
	606	return ret;
	607	}
953192ba MD	608	switch (node->u.logical.type) {
	609	default:
	610	fprintf(stderr, "[error] Unknown node type in %s\n",
	611	__func__);
	612	return -EINVAL;
	613
	614	case AST_OP_AND:
	615	insn.op = FILTER_OP_AND;
	616	break;
	617	case AST_OP_OR:
	618	insn.op = FILTER_OP_OR;
	619	break;
	620	}
	621	insn.skip_offset = (uint16_t) -1UL; /* Temporary */
	622	ret = bytecode_push_logical(&ctx->bytecode, &insn, 1, sizeof(insn),
	623	&skip_offset_loc);
	624	if (ret)
	625	return ret;
	626	/* Visit right child */
	627	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
	628	if (ret)
	629	return ret;
8cf9540a	630	/* Cast to s64 if float or field ref */
586dc72f	631	if ((node->u.binary.right->data_type == IR_DATA_FIELD_REF
5590fc2c	632	\|\| node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF
87942d06	633	\|\| node->u.binary.right->data_type == IR_DATA_EXPRESSION)
8cf9540a MD	634	\|\| node->u.binary.right->data_type == IR_DATA_FLOAT) {
	635	struct cast_op cast_insn;
	636
586dc72f	637	if (node->u.binary.right->data_type == IR_DATA_FIELD_REF
5590fc2c	638	\|\| node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF
87942d06	639	\|\| node->u.binary.right->data_type == IR_DATA_EXPRESSION) {
29fefef8 MD	640	cast_insn.op = FILTER_OP_CAST_TO_S64;
	641	} else {
	642	cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
	643	}
8cf9540a MD	644	ret = bytecode_push(&ctx->bytecode, &cast_insn,
	645	1, sizeof(cast_insn));
	646	if (ret)
	647	return ret;
	648	}
953192ba MD	649	/* We now know where the logical op can skip. */
	650	target_loc = (uint16_t) bytecode_get_len(&ctx->bytecode->b);
	651	ret = bytecode_patch(&ctx->bytecode,
	652	&target_loc, /* Offset to jump to */
	653	skip_offset_loc, /* Where to patch */
	654	sizeof(uint16_t));
	655	return ret;
	656	}
	657
	658	/*
	659	* Postorder traversal of the tree. We need the children result before
	660	* we can evaluate the parent.
	661	*/
	662	static
	663	int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
	664	struct ir_op *node)
	665	{
	666	switch (node->op) {
	667	case IR_OP_UNKNOWN:
	668	default:
	669	fprintf(stderr, "[error] Unknown node type in %s\n",
	670	__func__);
	671	return -EINVAL;
	672
	673	case IR_OP_ROOT:
	674	return visit_node_root(ctx, node);
	675	case IR_OP_LOAD:
	676	return visit_node_load(ctx, node);
	677	case IR_OP_UNARY:
	678	return visit_node_unary(ctx, node);
	679	case IR_OP_BINARY:
	680	return visit_node_binary(ctx, node);
	681	case IR_OP_LOGICAL:
	682	return visit_node_logical(ctx, node);
	683	}
	684	}
	685
a187da1a	686	LTTNG_HIDDEN
953192ba MD	687	void filter_bytecode_free(struct filter_parser_ctx *ctx)
953192ba MD	688	{
7ca1dc6f DG	689	if (!ctx) {
	690	return;
	691	}
	692
3f0c8837 DG	693	if (ctx->bytecode) {
	694	free(ctx->bytecode);
	695	ctx->bytecode = NULL;
	696	}
	697
	698	if (ctx->bytecode_reloc) {
	699	free(ctx->bytecode_reloc);
	700	ctx->bytecode_reloc = NULL;
	701	}
953192ba MD	702	}
953192ba MD	703
a187da1a	704	LTTNG_HIDDEN
953192ba MD	705	int filter_visitor_bytecode_generate(struct filter_parser_ctx *ctx)
	706	{
	707	int ret;
	708
	709	ret = bytecode_init(&ctx->bytecode);
	710	if (ret)
	711	return ret;
	712	ret = bytecode_init(&ctx->bytecode_reloc);
	713	if (ret)
	714	goto error;
	715	ret = recursive_visit_gen_bytecode(ctx, ctx->ir_root);
	716	if (ret)
	717	goto error;
	718
	719	/* Finally, append symbol table to bytecode */
	720	ctx->bytecode->b.reloc_table_offset = bytecode_get_len(&ctx->bytecode->b);
	721	return bytecode_push(&ctx->bytecode, ctx->bytecode_reloc->b.data,
	722	1, bytecode_get_len(&ctx->bytecode_reloc->b));
	723
	724	error:
	725	filter_bytecode_free(ctx);
	726	return ret;
	727	}