[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(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;
	}
	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;
	}
	}
}

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_GET_CONTEXT_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
				|| node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_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_GET_CONTEXT_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
				|| node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_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);
	}
}

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
953192ba MD	160	static
	161	int visit_node_load(struct filter_parser_ctx ctx, struct ir_op node)
	162	{
	163	int ret;
	164
	165	switch (node->data_type) {
	166	case IR_DATA_UNKNOWN:
	167	default:
	168	fprintf(stderr, "[error] Unknown data type in %s\n",
	169	__func__);
	170	return -EINVAL;
	171
	172	case IR_DATA_STRING:
	173	{
	174	struct load_op *insn;
	175	uint32_t insn_len = sizeof(struct load_op)
9f449915	176	+ strlen(node->u.load.u.string.value) + 1;
953192ba MD	177
	178	insn = calloc(insn_len, 1);
	179	if (!insn)
	180	return -ENOMEM;
9f449915 PP	181
	182	switch (node->u.load.u.string.type) {
	183	case IR_LOAD_STRING_TYPE_GLOB_STAR:
	184	/*
	185	* We explicitly tell the interpreter here that
	186	* this load is a full star globbing pattern so
	187	* that the appropriate matching function can be
	188	* called. Also, see comment below.
	189	*/
	190	insn->op = FILTER_OP_LOAD_STAR_GLOB_STRING;
	191	break;
	192	default:
	193	/*
	194	* This is the "legacy" string, which includes
	195	* star globbing patterns with a star only at
	196	* the end. Both "plain" and "star at the end"
	197	* literal strings are handled at the same place
	198	* by the tracer's filter bytecode interpreter,
	199	* whereas full star globbing patterns (stars
	200	* can be anywhere in the string) is a special
	201	* case.
	202	*/
	203	insn->op = FILTER_OP_LOAD_STRING;
	204	break;
	205	}
	206
	207	strcpy(insn->data, node->u.load.u.string.value);
953192ba MD	208	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	209	free(insn);
	210	return ret;
	211	}
	212	case IR_DATA_NUMERIC:
	213	{
	214	struct load_op *insn;
	215	uint32_t insn_len = sizeof(struct load_op)
	216	+ sizeof(struct literal_numeric);
	217
	218	insn = calloc(insn_len, 1);
	219	if (!insn)
	220	return -ENOMEM;
	221	insn->op = FILTER_OP_LOAD_S64;
58d494e4	222	memcpy(insn->data, &node->u.load.u.num, sizeof(int64_t));
953192ba MD	223	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	224	free(insn);
	225	return ret;
	226	}
e90d8561 MD	227	case IR_DATA_FLOAT:
	228	{
	229	struct load_op *insn;
	230	uint32_t insn_len = sizeof(struct load_op)
	231	+ sizeof(struct literal_double);
	232
	233	insn = calloc(insn_len, 1);
	234	if (!insn)
	235	return -ENOMEM;
	236	insn->op = FILTER_OP_LOAD_DOUBLE;
58d494e4	237	memcpy(insn->data, &node->u.load.u.flt, sizeof(double));
e90d8561 MD	238	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	239	free(insn);
	240	return ret;
	241	}
586dc72f MD	242	case IR_DATA_FIELD_REF: /* fall-through */
586dc72f MD	243	case IR_DATA_GET_CONTEXT_REF:
953192ba MD	244	{
	245	struct load_op *insn;
	246	uint32_t insn_len = sizeof(struct load_op)
	247	+ sizeof(struct field_ref);
	248	struct field_ref ref_offset;
ec96a8f6 MD	249	uint32_t reloc_offset_u32;
ec96a8f6 MD	250	uint16_t reloc_offset;
953192ba MD	251
	252	insn = calloc(insn_len, 1);
	253	if (!insn)
	254	return -ENOMEM;
586dc72f MD	255	switch(node->data_type) {
	256	case IR_DATA_FIELD_REF:
	257	insn->op = FILTER_OP_LOAD_FIELD_REF;
	258	break;
	259	case IR_DATA_GET_CONTEXT_REF:
	260	insn->op = FILTER_OP_GET_CONTEXT_REF;
	261	break;
	262	default:
3a68137c	263	free(insn);
586dc72f MD	264	return -EINVAL;
586dc72f MD	265	}
953192ba MD	266	ref_offset.offset = (uint16_t) -1U;
953192ba MD	267	memcpy(insn->data, &ref_offset, sizeof(ref_offset));
65775683	268	/* reloc_offset points to struct load_op */
ec96a8f6 MD	269	reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b);
	270	if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
	271	free(insn);
	272	return -EINVAL;
	273	}
	274	reloc_offset = (uint16_t) reloc_offset_u32;
953192ba MD	275	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	276	if (ret) {
	277	free(insn);
	278	return ret;
	279	}
	280	/* append reloc */
	281	ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset,
	282	1, sizeof(reloc_offset));
	283	if (ret) {
	284	free(insn);
	285	return ret;
	286	}
	287	ret = bytecode_push(&ctx->bytecode_reloc, node->u.load.u.ref,
	288	1, strlen(node->u.load.u.ref) + 1);
	289	free(insn);
	290	return ret;
	291	}
	292	}
	293	}
	294
	295	static
	296	int visit_node_unary(struct filter_parser_ctx ctx, struct ir_op node)
	297	{
	298	int ret;
	299	struct unary_op insn;
	300
	301	/* Visit child */
	302	ret = recursive_visit_gen_bytecode(ctx, node->u.unary.child);
	303	if (ret)
	304	return ret;
	305
	306	/* Generate end of bytecode instruction */
	307	switch (node->u.unary.type) {
	308	case AST_UNARY_UNKNOWN:
	309	default:
	310	fprintf(stderr, "[error] Unknown unary node type in %s\n",
	311	__func__);
	312	return -EINVAL;
	313	case AST_UNARY_PLUS:
	314	/* Nothing to do. */
	315	return 0;
	316	case AST_UNARY_MINUS:
	317	insn.op = FILTER_OP_UNARY_MINUS;
953192ba MD	318	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	319	case AST_UNARY_NOT:
	320	insn.op = FILTER_OP_UNARY_NOT;
953192ba MD	321	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	322	}
	323	}
	324
	325	/*
	326	* Binary comparator nesting is disallowed. This allows fitting into
	327	* only 2 registers.
	328	*/
	329	static
	330	int visit_node_binary(struct filter_parser_ctx ctx, struct ir_op node)
	331	{
	332	int ret;
	333	struct binary_op insn;
	334
	335	/* Visit child */
	336	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left);
	337	if (ret)
	338	return ret;
	339	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
	340	if (ret)
	341	return ret;
	342
	343	switch (node->u.binary.type) {
	344	case AST_OP_UNKNOWN:
	345	default:
	346	fprintf(stderr, "[error] Unknown unary node type in %s\n",
	347	__func__);
	348	return -EINVAL;
	349
	350	case AST_OP_AND:
	351	case AST_OP_OR:
	352	fprintf(stderr, "[error] Unexpected logical node type in %s\n",
	353	__func__);
	354	return -EINVAL;
	355
	356	case AST_OP_MUL:
	357	insn.op = FILTER_OP_MUL;
	358	break;
	359	case AST_OP_DIV:
	360	insn.op = FILTER_OP_DIV;
	361	break;
	362	case AST_OP_MOD:
	363	insn.op = FILTER_OP_MOD;
	364	break;
	365	case AST_OP_PLUS:
	366	insn.op = FILTER_OP_PLUS;
	367	break;
	368	case AST_OP_MINUS:
	369	insn.op = FILTER_OP_MINUS;
	370	break;
	371	case AST_OP_RSHIFT:
	372	insn.op = FILTER_OP_RSHIFT;
	373	break;
	374	case AST_OP_LSHIFT:
	375	insn.op = FILTER_OP_LSHIFT;
	376	break;
	377	case AST_OP_BIN_AND:
	378	insn.op = FILTER_OP_BIN_AND;
	379	break;
	380	case AST_OP_BIN_OR:
	381	insn.op = FILTER_OP_BIN_OR;
	382	break;
	383	case AST_OP_BIN_XOR:
	384	insn.op = FILTER_OP_BIN_XOR;
385	break;
386
387	case AST_OP_EQ:
388	insn.op = FILTER_OP_EQ;
389	break;
390	case AST_OP_NE:
391	insn.op = FILTER_OP_NE;
392	break;
393	case AST_OP_GT:
394	insn.op = FILTER_OP_GT;
395	break;
396	case AST_OP_LT:
397	insn.op = FILTER_OP_LT;
398	break;
399	case AST_OP_GE:
400	insn.op = FILTER_OP_GE;
401	break;
402	case AST_OP_LE:
403	insn.op = FILTER_OP_LE;
404	break;
405	}
406	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
407	}
408
8cf9540a MD	409	/*
	410	* A logical op always return a s64 (1 or 0).
	411	*/
953192ba MD	412	static
	413	int visit_node_logical(struct filter_parser_ctx ctx, struct ir_op node)
	414	{
	415	int ret;
	416	struct logical_op insn;
	417	uint16_t skip_offset_loc;
	418	uint16_t target_loc;
	419
	420	/* Visit left child */
	421	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left);
	422	if (ret)
	423	return ret;
8cf9540a	424	/* Cast to s64 if float or field ref */
586dc72f MD	425	if ((node->u.binary.left->data_type == IR_DATA_FIELD_REF
586dc72f MD	426	\|\| node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF)
8cf9540a MD	427	\|\| node->u.binary.left->data_type == IR_DATA_FLOAT) {
	428	struct cast_op cast_insn;
	429
586dc72f MD	430	if (node->u.binary.left->data_type == IR_DATA_FIELD_REF
586dc72f MD	431	\|\| node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF) {
29fefef8 MD	432	cast_insn.op = FILTER_OP_CAST_TO_S64;
	433	} else {
	434	cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
	435	}
8cf9540a MD	436	ret = bytecode_push(&ctx->bytecode, &cast_insn,
	437	1, sizeof(cast_insn));
	438	if (ret)
	439	return ret;
	440	}
953192ba MD	441	switch (node->u.logical.type) {
	442	default:
	443	fprintf(stderr, "[error] Unknown node type in %s\n",
	444	__func__);
	445	return -EINVAL;
	446
	447	case AST_OP_AND:
	448	insn.op = FILTER_OP_AND;
	449	break;
	450	case AST_OP_OR:
	451	insn.op = FILTER_OP_OR;
	452	break;
	453	}
	454	insn.skip_offset = (uint16_t) -1UL; /* Temporary */
	455	ret = bytecode_push_logical(&ctx->bytecode, &insn, 1, sizeof(insn),
	456	&skip_offset_loc);
	457	if (ret)
	458	return ret;
	459	/* Visit right child */
	460	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
	461	if (ret)
	462	return ret;
8cf9540a	463	/* Cast to s64 if float or field ref */
586dc72f MD	464	if ((node->u.binary.right->data_type == IR_DATA_FIELD_REF
586dc72f MD	465	\|\| node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF)
8cf9540a MD	466	\|\| node->u.binary.right->data_type == IR_DATA_FLOAT) {
	467	struct cast_op cast_insn;
	468
586dc72f MD	469	if (node->u.binary.right->data_type == IR_DATA_FIELD_REF
586dc72f MD	470	\|\| node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF) {
29fefef8 MD	471	cast_insn.op = FILTER_OP_CAST_TO_S64;
	472	} else {
	473	cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
	474	}
8cf9540a MD	475	ret = bytecode_push(&ctx->bytecode, &cast_insn,
	476	1, sizeof(cast_insn));
	477	if (ret)
	478	return ret;
	479	}
953192ba MD	480	/* We now know where the logical op can skip. */
	481	target_loc = (uint16_t) bytecode_get_len(&ctx->bytecode->b);
	482	ret = bytecode_patch(&ctx->bytecode,
	483	&target_loc, /* Offset to jump to */
	484	skip_offset_loc, /* Where to patch */
	485	sizeof(uint16_t));
	486	return ret;
	487	}
	488
	489	/*
	490	* Postorder traversal of the tree. We need the children result before
	491	* we can evaluate the parent.
	492	*/
	493	static
	494	int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
	495	struct ir_op *node)
	496	{
	497	switch (node->op) {
	498	case IR_OP_UNKNOWN:
	499	default:
	500	fprintf(stderr, "[error] Unknown node type in %s\n",
	501	__func__);
	502	return -EINVAL;
	503
	504	case IR_OP_ROOT:
	505	return visit_node_root(ctx, node);
	506	case IR_OP_LOAD:
	507	return visit_node_load(ctx, node);
	508	case IR_OP_UNARY:
	509	return visit_node_unary(ctx, node);
	510	case IR_OP_BINARY:
	511	return visit_node_binary(ctx, node);
	512	case IR_OP_LOGICAL:
	513	return visit_node_logical(ctx, node);
	514	}
	515	}
	516
a187da1a	517	LTTNG_HIDDEN
953192ba MD	518	void filter_bytecode_free(struct filter_parser_ctx *ctx)
953192ba MD	519	{
7ca1dc6f DG	520	if (!ctx) {
	521	return;
	522	}
	523
3f0c8837 DG	524	if (ctx->bytecode) {
	525	free(ctx->bytecode);
	526	ctx->bytecode = NULL;
	527	}
	528
	529	if (ctx->bytecode_reloc) {
	530	free(ctx->bytecode_reloc);
	531	ctx->bytecode_reloc = NULL;
	532	}
953192ba MD	533	}
953192ba MD	534
a187da1a	535	LTTNG_HIDDEN
953192ba MD	536	int filter_visitor_bytecode_generate(struct filter_parser_ctx *ctx)
	537	{
	538	int ret;
	539
	540	ret = bytecode_init(&ctx->bytecode);
	541	if (ret)
	542	return ret;
	543	ret = bytecode_init(&ctx->bytecode_reloc);
	544	if (ret)
	545	goto error;
	546	ret = recursive_visit_gen_bytecode(ctx, ctx->ir_root);
	547	if (ret)
	548	goto error;
	549
	550	/* Finally, append symbol table to bytecode */
	551	ctx->bytecode->b.reloc_table_offset = bytecode_get_len(&ctx->bytecode->b);
	552	return bytecode_push(&ctx->bytecode, ctx->bytecode_reloc->b.data,
	553	1, bytecode_get_len(&ctx->bytecode_reloc->b));
	554
	555	error:
	556	filter_bytecode_free(ctx);
	557	return ret;
	558	}