[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 "align.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		PAGE_SIZE
#define INIT_ALLOC_SIZE		4

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

static inline int fls(unsigned int x)
{
	int r = 32;

	if (!x)
		return 0;
	if (!(x & 0xFFFF0000U)) {
		x <<= 16;
		r -= 16;
	}
	if (!(x & 0xFF000000U)) {
		x <<= 8;
		r -= 8;
	}
	if (!(x & 0xF0000000U)) {
		x <<= 4;
		r -= 4;
	}
	if (!(x & 0xC0000000U)) {
		x <<= 2;
		r -= 2;
	}
	if (!(x & 0x80000000U)) {
		x <<= 1;
		r -= 1;
	}
	return r;
}

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

	order = 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) + 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:	/* 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:
			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)
{
	free(ctx->bytecode);
	ctx->bytecode = NULL;
	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>
	25	#include "align.h"
	26	#include "filter-bytecode.h"
	27	#include "filter-ir.h"
	28	#include "filter-ast.h"
	29
a187da1a DG	30	#include <common/macros.h>
a187da1a DG	31
953192ba MD	32	#ifndef max_t
	33	#define max_t(type, a, b) ((type) ((a) > (b) ? (a) : (b)))
	34	#endif
	35
	36	//#define INIT_ALLOC_SIZE PAGE_SIZE
	37	#define INIT_ALLOC_SIZE 4
	38
	39	static
	40	int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
	41	struct ir_op *node);
	42
01a204f0 CB	43	static inline int fls(unsigned int x)
	44	{
	45	int r = 32;
	46
	47	if (!x)
	48	return 0;
	49	if (!(x & 0xFFFF0000U)) {
	50	x <<= 16;
	51	r -= 16;
	52	}
	53	if (!(x & 0xFF000000U)) {
	54	x <<= 8;
	55	r -= 8;
	56	}
	57	if (!(x & 0xF0000000U)) {
	58	x <<= 4;
	59	r -= 4;
	60	}
	61	if (!(x & 0xC0000000U)) {
	62	x <<= 2;
	63	r -= 2;
	64	}
	65	if (!(x & 0x80000000U)) {
	66	x <<= 1;
	67	r -= 1;
	68	}
	69	return r;
	70	}
	71
	72	static inline int get_count_order(unsigned int count)
	73	{
	74	int order;
	75
	76	order = fls(count) - 1;
	77	if (count & (count - 1))
	78	order++;
	79	return order;
	80	}
	81
953192ba	82	static
53a80697	83	int bytecode_init(struct lttng_filter_bytecode_alloc **fb)
953192ba	84	{
1029587a MD	85	uint32_t alloc_len;
	86
	87	alloc_len = sizeof(struct lttng_filter_bytecode_alloc) + INIT_ALLOC_SIZE;
	88	*fb = calloc(alloc_len, 1);
953192ba MD	89	if (!*fb) {
	90	return -ENOMEM;
	91	} else {
1029587a	92	(*fb)->alloc_len = alloc_len;
953192ba MD	93	return 0;
	94	}
	95	}
	96
	97	static
53a80697	98	int32_t bytecode_reserve(struct lttng_filter_bytecode_alloc **fb, uint32_t align, uint32_t len)
953192ba MD	99	{
	100	int32_t ret;
	101	uint32_t padding = offset_align((*fb)->b.len, align);
ec96a8f6	102	uint32_t new_len = (*fb)->b.len + padding + len;
1029587a	103	uint32_t new_alloc_len = sizeof(struct lttng_filter_bytecode_alloc) + new_len;
ec96a8f6	104	uint32_t old_alloc_len = (*fb)->alloc_len;
953192ba	105
ec96a8f6	106	if (new_len > LTTNG_FILTER_MAX_LEN)
5ddb0a08 CB	107	return -EINVAL;
5ddb0a08 CB	108
ec96a8f6	109	if (new_alloc_len > old_alloc_len) {
d0b96690 DG	110	struct lttng_filter_bytecode_alloc *newptr;
d0b96690 DG	111
ec96a8f6 MD	112	new_alloc_len =
ec96a8f6 MD	113	max_t(uint32_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1);
d0b96690 DG	114	newptr = realloc(*fb, new_alloc_len);
d0b96690 DG	115	if (!newptr)
953192ba	116	return -ENOMEM;
d0b96690	117	*fb = newptr;
1029587a	118	/* We zero directly the memory from start of allocation. */
ec96a8f6 MD	119	memset(&((char ) fb)[old_alloc_len], 0, new_alloc_len - old_alloc_len);
ec96a8f6 MD	120	(*fb)->alloc_len = new_alloc_len;
953192ba MD	121	}
	122	(*fb)->b.len += padding;
	123	ret = (*fb)->b.len;
	124	(*fb)->b.len += len;
	125	return ret;
	126	}
	127
	128	static
53a80697	129	int bytecode_push(struct lttng_filter_bytecode_alloc *fb, const void data,
953192ba MD	130	uint32_t align, uint32_t len)
	131	{
	132	int32_t offset;
	133
	134	offset = bytecode_reserve(fb, align, len);
	135	if (offset < 0)
	136	return offset;
	137	memcpy(&(*fb)->b.data[offset], data, len);
	138	return 0;
	139	}
	140
	141	static
53a80697	142	int bytecode_push_logical(struct lttng_filter_bytecode_alloc **fb,
953192ba MD	143	struct logical_op *data,
	144	uint32_t align, uint32_t len,
	145	uint16_t *skip_offset)
	146	{
	147	int32_t offset;
	148
	149	offset = bytecode_reserve(fb, align, len);
	150	if (offset < 0)
	151	return offset;
	152	memcpy(&(*fb)->b.data[offset], data, len);
	153	*skip_offset =
	154	(void ) &((struct logical_op ) &(*fb)->b.data[offset])->skip_offset
	155	- (void ) &(fb)->b.data[0];
	156	return 0;
	157	}
	158
	159	static
53a80697	160	int bytecode_patch(struct lttng_filter_bytecode_alloc **fb,
953192ba MD	161	const void *data,
	162	uint16_t offset,
	163	uint32_t len)
	164	{
	165	if (offset >= (*fb)->b.len) {
	166	return -EINVAL;
	167	}
	168	memcpy(&(*fb)->b.data[offset], data, len);
	169	return 0;
	170	}
	171
	172	static
	173	int visit_node_root(struct filter_parser_ctx ctx, struct ir_op node)
	174	{
	175	int ret;
	176	struct return_op insn;
	177
	178	/* Visit child */
	179	ret = recursive_visit_gen_bytecode(ctx, node->u.root.child);
	180	if (ret)
	181	return ret;
	182
	183	/* Generate end of bytecode instruction */
	184	insn.op = FILTER_OP_RETURN;
	185	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	186	}
	187
953192ba MD	188	static
	189	int visit_node_load(struct filter_parser_ctx ctx, struct ir_op node)
	190	{
	191	int ret;
	192
	193	switch (node->data_type) {
	194	case IR_DATA_UNKNOWN:
	195	default:
	196	fprintf(stderr, "[error] Unknown data type in %s\n",
	197	__func__);
	198	return -EINVAL;
	199
	200	case IR_DATA_STRING:
	201	{
	202	struct load_op *insn;
	203	uint32_t insn_len = sizeof(struct load_op)
	204	+ strlen(node->u.load.u.string) + 1;
	205
	206	insn = calloc(insn_len, 1);
	207	if (!insn)
	208	return -ENOMEM;
	209	insn->op = FILTER_OP_LOAD_STRING;
953192ba MD	210	strcpy(insn->data, node->u.load.u.string);
	211	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	212	free(insn);
	213	return ret;
	214	}
	215	case IR_DATA_NUMERIC:
	216	{
	217	struct load_op *insn;
	218	uint32_t insn_len = sizeof(struct load_op)
	219	+ sizeof(struct literal_numeric);
	220
	221	insn = calloc(insn_len, 1);
	222	if (!insn)
	223	return -ENOMEM;
	224	insn->op = FILTER_OP_LOAD_S64;
953192ba MD	225	(int64_t ) insn->data = node->u.load.u.num;
	226	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	227	free(insn);
	228	return ret;
	229	}
e90d8561 MD	230	case IR_DATA_FLOAT:
	231	{
	232	struct load_op *insn;
	233	uint32_t insn_len = sizeof(struct load_op)
	234	+ sizeof(struct literal_double);
	235
	236	insn = calloc(insn_len, 1);
	237	if (!insn)
	238	return -ENOMEM;
	239	insn->op = FILTER_OP_LOAD_DOUBLE;
e90d8561 MD	240	(double ) insn->data = node->u.load.u.flt;
	241	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	242	free(insn);
	243	return ret;
	244	}
586dc72f MD	245	case IR_DATA_FIELD_REF: /* fall-through */
586dc72f MD	246	case IR_DATA_GET_CONTEXT_REF:
953192ba MD	247	{
	248	struct load_op *insn;
	249	uint32_t insn_len = sizeof(struct load_op)
	250	+ sizeof(struct field_ref);
	251	struct field_ref ref_offset;
ec96a8f6 MD	252	uint32_t reloc_offset_u32;
ec96a8f6 MD	253	uint16_t reloc_offset;
953192ba MD	254
	255	insn = calloc(insn_len, 1);
	256	if (!insn)
	257	return -ENOMEM;
586dc72f MD	258	switch(node->data_type) {
	259	case IR_DATA_FIELD_REF:
	260	insn->op = FILTER_OP_LOAD_FIELD_REF;
	261	break;
	262	case IR_DATA_GET_CONTEXT_REF:
	263	insn->op = FILTER_OP_GET_CONTEXT_REF;
	264	break;
	265	default:
	266	return -EINVAL;
	267	}
953192ba MD	268	ref_offset.offset = (uint16_t) -1U;
953192ba MD	269	memcpy(insn->data, &ref_offset, sizeof(ref_offset));
65775683	270	/* reloc_offset points to struct load_op */
ec96a8f6 MD	271	reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b);
	272	if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
	273	free(insn);
	274	return -EINVAL;
	275	}
	276	reloc_offset = (uint16_t) reloc_offset_u32;
953192ba MD	277	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	278	if (ret) {
	279	free(insn);
	280	return ret;
	281	}
	282	/* append reloc */
	283	ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset,
	284	1, sizeof(reloc_offset));
	285	if (ret) {
	286	free(insn);
	287	return ret;
	288	}
	289	ret = bytecode_push(&ctx->bytecode_reloc, node->u.load.u.ref,
	290	1, strlen(node->u.load.u.ref) + 1);
	291	free(insn);
	292	return ret;
	293	}
	294	}
	295	}
	296
	297	static
	298	int visit_node_unary(struct filter_parser_ctx ctx, struct ir_op node)
	299	{
	300	int ret;
	301	struct unary_op insn;
	302
	303	/* Visit child */
	304	ret = recursive_visit_gen_bytecode(ctx, node->u.unary.child);
	305	if (ret)
	306	return ret;
	307
	308	/* Generate end of bytecode instruction */
	309	switch (node->u.unary.type) {
	310	case AST_UNARY_UNKNOWN:
	311	default:
	312	fprintf(stderr, "[error] Unknown unary node type in %s\n",
	313	__func__);
	314	return -EINVAL;
	315	case AST_UNARY_PLUS:
	316	/* Nothing to do. */
	317	return 0;
	318	case AST_UNARY_MINUS:
	319	insn.op = FILTER_OP_UNARY_MINUS;
953192ba MD	320	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	321	case AST_UNARY_NOT:
	322	insn.op = FILTER_OP_UNARY_NOT;
953192ba MD	323	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	324	}
	325	}
	326
	327	/*
	328	* Binary comparator nesting is disallowed. This allows fitting into
	329	* only 2 registers.
	330	*/
	331	static
	332	int visit_node_binary(struct filter_parser_ctx ctx, struct ir_op node)
	333	{
	334	int ret;
	335	struct binary_op insn;
	336
	337	/* Visit child */
	338	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left);
	339	if (ret)
	340	return ret;
	341	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
	342	if (ret)
	343	return ret;
	344
	345	switch (node->u.binary.type) {
	346	case AST_OP_UNKNOWN:
	347	default:
	348	fprintf(stderr, "[error] Unknown unary node type in %s\n",
	349	__func__);
	350	return -EINVAL;
	351
	352	case AST_OP_AND:
	353	case AST_OP_OR:
	354	fprintf(stderr, "[error] Unexpected logical node type in %s\n",
	355	__func__);
	356	return -EINVAL;
	357
	358	case AST_OP_MUL:
	359	insn.op = FILTER_OP_MUL;
	360	break;
	361	case AST_OP_DIV:
	362	insn.op = FILTER_OP_DIV;
	363	break;
	364	case AST_OP_MOD:
	365	insn.op = FILTER_OP_MOD;
	366	break;
	367	case AST_OP_PLUS:
	368	insn.op = FILTER_OP_PLUS;
	369	break;
	370	case AST_OP_MINUS:
	371	insn.op = FILTER_OP_MINUS;
	372	break;
	373	case AST_OP_RSHIFT:
	374	insn.op = FILTER_OP_RSHIFT;
	375	break;
	376	case AST_OP_LSHIFT:
	377	insn.op = FILTER_OP_LSHIFT;
	378	break;
	379	case AST_OP_BIN_AND:
	380	insn.op = FILTER_OP_BIN_AND;
	381	break;
	382	case AST_OP_BIN_OR:
	383	insn.op = FILTER_OP_BIN_OR;
	384	break;
	385	case AST_OP_BIN_XOR:
	386	insn.op = FILTER_OP_BIN_XOR;
387	break;
388
389	case AST_OP_EQ:
390	insn.op = FILTER_OP_EQ;
391	break;
392	case AST_OP_NE:
393	insn.op = FILTER_OP_NE;
394	break;
395	case AST_OP_GT:
396	insn.op = FILTER_OP_GT;
397	break;
398	case AST_OP_LT:
399	insn.op = FILTER_OP_LT;
400	break;
401	case AST_OP_GE:
402	insn.op = FILTER_OP_GE;
403	break;
404	case AST_OP_LE:
405	insn.op = FILTER_OP_LE;
406	break;
407	}
408	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
409	}
410
8cf9540a MD	411	/*
	412	* A logical op always return a s64 (1 or 0).
	413	*/
953192ba MD	414	static
	415	int visit_node_logical(struct filter_parser_ctx ctx, struct ir_op node)
	416	{
	417	int ret;
	418	struct logical_op insn;
	419	uint16_t skip_offset_loc;
	420	uint16_t target_loc;
	421
	422	/* Visit left child */
	423	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left);
	424	if (ret)
	425	return ret;
8cf9540a	426	/* Cast to s64 if float or field ref */
586dc72f MD	427	if ((node->u.binary.left->data_type == IR_DATA_FIELD_REF
586dc72f MD	428	\|\| node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF)
8cf9540a MD	429	\|\| node->u.binary.left->data_type == IR_DATA_FLOAT) {
	430	struct cast_op cast_insn;
	431
586dc72f MD	432	if (node->u.binary.left->data_type == IR_DATA_FIELD_REF
586dc72f MD	433	\|\| node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF) {
29fefef8 MD	434	cast_insn.op = FILTER_OP_CAST_TO_S64;
	435	} else {
	436	cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
	437	}
8cf9540a MD	438	ret = bytecode_push(&ctx->bytecode, &cast_insn,
	439	1, sizeof(cast_insn));
	440	if (ret)
	441	return ret;
	442	}
953192ba MD	443	switch (node->u.logical.type) {
	444	default:
	445	fprintf(stderr, "[error] Unknown node type in %s\n",
	446	__func__);
	447	return -EINVAL;
	448
	449	case AST_OP_AND:
	450	insn.op = FILTER_OP_AND;
	451	break;
	452	case AST_OP_OR:
	453	insn.op = FILTER_OP_OR;
	454	break;
	455	}
	456	insn.skip_offset = (uint16_t) -1UL; /* Temporary */
	457	ret = bytecode_push_logical(&ctx->bytecode, &insn, 1, sizeof(insn),
	458	&skip_offset_loc);
	459	if (ret)
	460	return ret;
	461	/* Visit right child */
	462	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
	463	if (ret)
	464	return ret;
8cf9540a	465	/* Cast to s64 if float or field ref */
586dc72f MD	466	if ((node->u.binary.right->data_type == IR_DATA_FIELD_REF
586dc72f MD	467	\|\| node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF)
8cf9540a MD	468	\|\| node->u.binary.right->data_type == IR_DATA_FLOAT) {
	469	struct cast_op cast_insn;
	470
586dc72f MD	471	if (node->u.binary.right->data_type == IR_DATA_FIELD_REF
586dc72f MD	472	\|\| node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF) {
29fefef8 MD	473	cast_insn.op = FILTER_OP_CAST_TO_S64;
	474	} else {
	475	cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
	476	}
8cf9540a MD	477	ret = bytecode_push(&ctx->bytecode, &cast_insn,
	478	1, sizeof(cast_insn));
	479	if (ret)
	480	return ret;
	481	}
953192ba MD	482	/* We now know where the logical op can skip. */
	483	target_loc = (uint16_t) bytecode_get_len(&ctx->bytecode->b);
	484	ret = bytecode_patch(&ctx->bytecode,
	485	&target_loc, /* Offset to jump to */
	486	skip_offset_loc, /* Where to patch */
	487	sizeof(uint16_t));
	488	return ret;
	489	}
	490
	491	/*
	492	* Postorder traversal of the tree. We need the children result before
	493	* we can evaluate the parent.
	494	*/
	495	static
	496	int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
	497	struct ir_op *node)
	498	{
	499	switch (node->op) {
	500	case IR_OP_UNKNOWN:
	501	default:
	502	fprintf(stderr, "[error] Unknown node type in %s\n",
	503	__func__);
	504	return -EINVAL;
	505
	506	case IR_OP_ROOT:
	507	return visit_node_root(ctx, node);
	508	case IR_OP_LOAD:
	509	return visit_node_load(ctx, node);
	510	case IR_OP_UNARY:
	511	return visit_node_unary(ctx, node);
	512	case IR_OP_BINARY:
	513	return visit_node_binary(ctx, node);
	514	case IR_OP_LOGICAL:
	515	return visit_node_logical(ctx, node);
	516	}
	517	}
	518
a187da1a	519	LTTNG_HIDDEN
953192ba MD	520	void filter_bytecode_free(struct filter_parser_ctx *ctx)
	521	{
	522	free(ctx->bytecode);
	523	ctx->bytecode = NULL;
	524	free(ctx->bytecode_reloc);
	525	ctx->bytecode_reloc = NULL;
	526	}
	527
a187da1a	528	LTTNG_HIDDEN
953192ba MD	529	int filter_visitor_bytecode_generate(struct filter_parser_ctx *ctx)
	530	{
	531	int ret;
	532
	533	ret = bytecode_init(&ctx->bytecode);
	534	if (ret)
	535	return ret;
	536	ret = bytecode_init(&ctx->bytecode_reloc);
	537	if (ret)
	538	goto error;
	539	ret = recursive_visit_gen_bytecode(ctx, ctx->ir_root);
	540	if (ret)
	541	goto error;
	542
	543	/* Finally, append symbol table to bytecode */
	544	ctx->bytecode->b.reloc_table_offset = bytecode_get_len(&ctx->bytecode->b);
	545	return bytecode_push(&ctx->bytecode, ctx->bytecode_reloc->b.data,
	546	1, bytecode_get_len(&ctx->bytecode_reloc->b));
	547
	548	error:
	549	filter_bytecode_free(ctx);
	550	return ret;
	551	}