[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"

#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)
{
	*fb = calloc(sizeof(struct lttng_filter_bytecode_alloc) + INIT_ALLOC_SIZE, 1);
	if (!*fb) {
		return -ENOMEM;
	} else {
		(*fb)->alloc_len = INIT_ALLOC_SIZE;
		return 0;
	}
}

static
int32_t bytecode_reserve(struct lttng_filter_bytecode_alloc **fb, uint32_t align, uint32_t len)
{
	int32_t ret;
	uint32_t padding = offset_align((*fb)->b.len, align);
	uint32_t new_len = (*fb)->b.len + padding + len;
	uint32_t new_alloc_len = sizeof(struct lttng_filter_bytecode) + 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) {
		new_alloc_len =
			max_t(uint32_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1);
		*fb = realloc(*fb, new_alloc_len);
		if (!*fb)
			return -ENOMEM;
		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:
	{
		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;
		insn->op = FILTER_OP_LOAD_FIELD_REF;
		ref_offset.offset = (uint16_t) -1U;
		memcpy(insn->data, &ref_offset, sizeof(ref_offset));
		/* reloc_offset points to struct load_op */
		reloc_offset_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_FLOAT) {
		struct cast_op cast_insn;

		if (node->u.binary.left->data_type == IR_DATA_FIELD_REF) {
			cast_insn.op = FILTER_OP_CAST_TO_S64;
		} else {
			cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
		}
		ret = bytecode_push(&ctx->bytecode, &cast_insn,
					1, sizeof(cast_insn));
		if (ret)
			return ret;
	}
	switch (node->u.logical.type) {
	default:
		fprintf(stderr, "[error] Unknown node type in %s\n",
			__func__);
		return -EINVAL;

	case AST_OP_AND:
		insn.op = FILTER_OP_AND;
		break;
	case AST_OP_OR:
		insn.op = FILTER_OP_OR;
		break;
	}
	insn.skip_offset = (uint16_t) -1UL;	/* Temporary */
	ret = bytecode_push_logical(&ctx->bytecode, &insn, 1, sizeof(insn),
			&skip_offset_loc);
	if (ret)
		return ret;
	/* Visit right child */
	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
	if (ret)
		return ret;
	/* Cast to s64 if float or field ref */
	if (node->u.binary.right->data_type == IR_DATA_FIELD_REF
			|| node->u.binary.right->data_type == IR_DATA_FLOAT) {
		struct cast_op cast_insn;

		if (node->u.binary.right->data_type == IR_DATA_FIELD_REF) {
			cast_insn.op = FILTER_OP_CAST_TO_S64;
		} else {
			cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
		}
		ret = bytecode_push(&ctx->bytecode, &cast_insn,
					1, sizeof(cast_insn));
		if (ret)
			return ret;
	}
	/* We now know where the logical op can skip. */
	target_loc = (uint16_t) bytecode_get_len(&ctx->bytecode->b);
	ret = bytecode_patch(&ctx->bytecode,
			&target_loc,			/* Offset to jump to */
			skip_offset_loc,		/* Where to patch */
			sizeof(uint16_t));
	return ret;
}

/*
 * Postorder traversal of the tree. We need the children result before
 * we can evaluate the parent.
 */
static
int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
		struct ir_op *node)
{
	switch (node->op) {
	case IR_OP_UNKNOWN:
	default:
		fprintf(stderr, "[error] Unknown node type in %s\n",
			__func__);
		return -EINVAL;

	case IR_OP_ROOT:
		return visit_node_root(ctx, node);
	case IR_OP_LOAD:
		return visit_node_load(ctx, node);
	case IR_OP_UNARY:
		return visit_node_unary(ctx, node);
	case IR_OP_BINARY:
		return visit_node_binary(ctx, node);
	case IR_OP_LOGICAL:
		return visit_node_logical(ctx, node);
	}
}

__attribute__((visibility("hidden")))
void filter_bytecode_free(struct filter_parser_ctx *ctx)
{
	free(ctx->bytecode);
	ctx->bytecode = NULL;
	free(ctx->bytecode_reloc);
	ctx->bytecode_reloc = NULL;
}

__attribute__((visibility("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
	30	#ifndef max_t
	31	#define max_t(type, a, b) ((type) ((a) > (b) ? (a) : (b)))
	32	#endif
	33
	34	//#define INIT_ALLOC_SIZE PAGE_SIZE
	35	#define INIT_ALLOC_SIZE 4
	36
	37	static
	38	int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
	39	struct ir_op *node);
	40
01a204f0 CB	41	static inline int fls(unsigned int x)
	42	{
	43	int r = 32;
	44
	45	if (!x)
	46	return 0;
	47	if (!(x & 0xFFFF0000U)) {
	48	x <<= 16;
	49	r -= 16;
	50	}
	51	if (!(x & 0xFF000000U)) {
	52	x <<= 8;
	53	r -= 8;
	54	}
	55	if (!(x & 0xF0000000U)) {
	56	x <<= 4;
	57	r -= 4;
	58	}
	59	if (!(x & 0xC0000000U)) {
	60	x <<= 2;
	61	r -= 2;
	62	}
	63	if (!(x & 0x80000000U)) {
	64	x <<= 1;
	65	r -= 1;
	66	}
	67	return r;
	68	}
	69
	70	static inline int get_count_order(unsigned int count)
	71	{
	72	int order;
	73
	74	order = fls(count) - 1;
	75	if (count & (count - 1))
	76	order++;
	77	return order;
	78	}
	79
953192ba	80	static
53a80697	81	int bytecode_init(struct lttng_filter_bytecode_alloc **fb)
953192ba	82	{
53a80697	83	*fb = calloc(sizeof(struct lttng_filter_bytecode_alloc) + INIT_ALLOC_SIZE, 1);
953192ba MD	84	if (!*fb) {
	85	return -ENOMEM;
	86	} else {
	87	(*fb)->alloc_len = INIT_ALLOC_SIZE;
	88	return 0;
	89	}
	90	}
	91
	92	static
53a80697	93	int32_t bytecode_reserve(struct lttng_filter_bytecode_alloc **fb, uint32_t align, uint32_t len)
953192ba MD	94	{
	95	int32_t ret;
	96	uint32_t padding = offset_align((*fb)->b.len, align);
ec96a8f6 MD	97	uint32_t new_len = (*fb)->b.len + padding + len;
	98	uint32_t new_alloc_len = sizeof(struct lttng_filter_bytecode) + new_len;
	99	uint32_t old_alloc_len = (*fb)->alloc_len;
953192ba	100
ec96a8f6	101	if (new_len > LTTNG_FILTER_MAX_LEN)
5ddb0a08 CB	102	return -EINVAL;
5ddb0a08 CB	103
ec96a8f6 MD	104	if (new_alloc_len > old_alloc_len) {
	105	new_alloc_len =
	106	max_t(uint32_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1);
	107	fb = realloc(fb, new_alloc_len);
953192ba MD	108	if (!*fb)
953192ba MD	109	return -ENOMEM;
ec96a8f6 MD	110	memset(&((char ) fb)[old_alloc_len], 0, new_alloc_len - old_alloc_len);
ec96a8f6 MD	111	(*fb)->alloc_len = new_alloc_len;
953192ba MD	112	}
	113	(*fb)->b.len += padding;
	114	ret = (*fb)->b.len;
	115	(*fb)->b.len += len;
	116	return ret;
	117	}
	118
	119	static
53a80697	120	int bytecode_push(struct lttng_filter_bytecode_alloc *fb, const void data,
953192ba MD	121	uint32_t align, uint32_t len)
	122	{
	123	int32_t offset;
	124
	125	offset = bytecode_reserve(fb, align, len);
	126	if (offset < 0)
	127	return offset;
	128	memcpy(&(*fb)->b.data[offset], data, len);
	129	return 0;
	130	}
	131
	132	static
53a80697	133	int bytecode_push_logical(struct lttng_filter_bytecode_alloc **fb,
953192ba MD	134	struct logical_op *data,
	135	uint32_t align, uint32_t len,
	136	uint16_t *skip_offset)
	137	{
	138	int32_t offset;
	139
	140	offset = bytecode_reserve(fb, align, len);
	141	if (offset < 0)
	142	return offset;
	143	memcpy(&(*fb)->b.data[offset], data, len);
	144	*skip_offset =
	145	(void ) &((struct logical_op ) &(*fb)->b.data[offset])->skip_offset
	146	- (void ) &(fb)->b.data[0];
	147	return 0;
	148	}
	149
	150	static
53a80697	151	int bytecode_patch(struct lttng_filter_bytecode_alloc **fb,
953192ba MD	152	const void *data,
	153	uint16_t offset,
	154	uint32_t len)
	155	{
	156	if (offset >= (*fb)->b.len) {
	157	return -EINVAL;
	158	}
	159	memcpy(&(*fb)->b.data[offset], data, len);
	160	return 0;
	161	}
	162
	163	static
	164	int visit_node_root(struct filter_parser_ctx ctx, struct ir_op node)
	165	{
	166	int ret;
	167	struct return_op insn;
	168
	169	/* Visit child */
	170	ret = recursive_visit_gen_bytecode(ctx, node->u.root.child);
	171	if (ret)
	172	return ret;
	173
	174	/* Generate end of bytecode instruction */
	175	insn.op = FILTER_OP_RETURN;
	176	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	177	}
	178
953192ba MD	179	static
	180	int visit_node_load(struct filter_parser_ctx ctx, struct ir_op node)
	181	{
	182	int ret;
	183
	184	switch (node->data_type) {
	185	case IR_DATA_UNKNOWN:
	186	default:
	187	fprintf(stderr, "[error] Unknown data type in %s\n",
	188	__func__);
	189	return -EINVAL;
	190
	191	case IR_DATA_STRING:
	192	{
	193	struct load_op *insn;
	194	uint32_t insn_len = sizeof(struct load_op)
	195	+ strlen(node->u.load.u.string) + 1;
	196
	197	insn = calloc(insn_len, 1);
	198	if (!insn)
	199	return -ENOMEM;
	200	insn->op = FILTER_OP_LOAD_STRING;
953192ba MD	201	strcpy(insn->data, node->u.load.u.string);
	202	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	203	free(insn);
	204	return ret;
	205	}
	206	case IR_DATA_NUMERIC:
	207	{
	208	struct load_op *insn;
	209	uint32_t insn_len = sizeof(struct load_op)
	210	+ sizeof(struct literal_numeric);
	211
	212	insn = calloc(insn_len, 1);
	213	if (!insn)
	214	return -ENOMEM;
	215	insn->op = FILTER_OP_LOAD_S64;
953192ba MD	216	(int64_t ) insn->data = node->u.load.u.num;
	217	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	218	free(insn);
	219	return ret;
	220	}
e90d8561 MD	221	case IR_DATA_FLOAT:
	222	{
	223	struct load_op *insn;
	224	uint32_t insn_len = sizeof(struct load_op)
	225	+ sizeof(struct literal_double);
	226
	227	insn = calloc(insn_len, 1);
	228	if (!insn)
	229	return -ENOMEM;
	230	insn->op = FILTER_OP_LOAD_DOUBLE;
e90d8561 MD	231	(double ) insn->data = node->u.load.u.flt;
	232	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	233	free(insn);
	234	return ret;
	235	}
953192ba MD	236	case IR_DATA_FIELD_REF:
	237	{
	238	struct load_op *insn;
	239	uint32_t insn_len = sizeof(struct load_op)
	240	+ sizeof(struct field_ref);
	241	struct field_ref ref_offset;
ec96a8f6 MD	242	uint32_t reloc_offset_u32;
ec96a8f6 MD	243	uint16_t reloc_offset;
953192ba MD	244
	245	insn = calloc(insn_len, 1);
	246	if (!insn)
	247	return -ENOMEM;
	248	insn->op = FILTER_OP_LOAD_FIELD_REF;
953192ba MD	249	ref_offset.offset = (uint16_t) -1U;
953192ba MD	250	memcpy(insn->data, &ref_offset, sizeof(ref_offset));
65775683	251	/* reloc_offset points to struct load_op */
ec96a8f6 MD	252	reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b);
	253	if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
	254	free(insn);
	255	return -EINVAL;
	256	}
	257	reloc_offset = (uint16_t) reloc_offset_u32;
953192ba MD	258	ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
	259	if (ret) {
	260	free(insn);
	261	return ret;
	262	}
	263	/* append reloc */
	264	ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset,
	265	1, sizeof(reloc_offset));
	266	if (ret) {
	267	free(insn);
	268	return ret;
	269	}
	270	ret = bytecode_push(&ctx->bytecode_reloc, node->u.load.u.ref,
	271	1, strlen(node->u.load.u.ref) + 1);
	272	free(insn);
	273	return ret;
	274	}
	275	}
	276	}
	277
	278	static
	279	int visit_node_unary(struct filter_parser_ctx ctx, struct ir_op node)
	280	{
	281	int ret;
	282	struct unary_op insn;
	283
	284	/* Visit child */
	285	ret = recursive_visit_gen_bytecode(ctx, node->u.unary.child);
	286	if (ret)
	287	return ret;
	288
	289	/* Generate end of bytecode instruction */
	290	switch (node->u.unary.type) {
	291	case AST_UNARY_UNKNOWN:
	292	default:
	293	fprintf(stderr, "[error] Unknown unary node type in %s\n",
	294	__func__);
	295	return -EINVAL;
	296	case AST_UNARY_PLUS:
	297	/* Nothing to do. */
	298	return 0;
	299	case AST_UNARY_MINUS:
	300	insn.op = FILTER_OP_UNARY_MINUS;
953192ba MD	301	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	302	case AST_UNARY_NOT:
	303	insn.op = FILTER_OP_UNARY_NOT;
953192ba MD	304	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
	305	}
	306	}
	307
	308	/*
	309	* Binary comparator nesting is disallowed. This allows fitting into
	310	* only 2 registers.
	311	*/
	312	static
	313	int visit_node_binary(struct filter_parser_ctx ctx, struct ir_op node)
	314	{
	315	int ret;
	316	struct binary_op insn;
	317
	318	/* Visit child */
	319	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left);
	320	if (ret)
	321	return ret;
	322	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
	323	if (ret)
	324	return ret;
	325
	326	switch (node->u.binary.type) {
	327	case AST_OP_UNKNOWN:
	328	default:
	329	fprintf(stderr, "[error] Unknown unary node type in %s\n",
	330	__func__);
	331	return -EINVAL;
	332
	333	case AST_OP_AND:
	334	case AST_OP_OR:
	335	fprintf(stderr, "[error] Unexpected logical node type in %s\n",
	336	__func__);
	337	return -EINVAL;
	338
	339	case AST_OP_MUL:
	340	insn.op = FILTER_OP_MUL;
	341	break;
	342	case AST_OP_DIV:
	343	insn.op = FILTER_OP_DIV;
	344	break;
	345	case AST_OP_MOD:
	346	insn.op = FILTER_OP_MOD;
	347	break;
	348	case AST_OP_PLUS:
	349	insn.op = FILTER_OP_PLUS;
	350	break;
	351	case AST_OP_MINUS:
	352	insn.op = FILTER_OP_MINUS;
	353	break;
	354	case AST_OP_RSHIFT:
	355	insn.op = FILTER_OP_RSHIFT;
	356	break;
	357	case AST_OP_LSHIFT:
	358	insn.op = FILTER_OP_LSHIFT;
	359	break;
	360	case AST_OP_BIN_AND:
	361	insn.op = FILTER_OP_BIN_AND;
	362	break;
	363	case AST_OP_BIN_OR:
	364	insn.op = FILTER_OP_BIN_OR;
	365	break;
	366	case AST_OP_BIN_XOR:
	367	insn.op = FILTER_OP_BIN_XOR;
368	break;
369
370	case AST_OP_EQ:
371	insn.op = FILTER_OP_EQ;
372	break;
373	case AST_OP_NE:
374	insn.op = FILTER_OP_NE;
375	break;
376	case AST_OP_GT:
377	insn.op = FILTER_OP_GT;
378	break;
379	case AST_OP_LT:
380	insn.op = FILTER_OP_LT;
381	break;
382	case AST_OP_GE:
383	insn.op = FILTER_OP_GE;
384	break;
385	case AST_OP_LE:
386	insn.op = FILTER_OP_LE;
387	break;
388	}
389	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
390	}
391
8cf9540a MD	392	/*
	393	* A logical op always return a s64 (1 or 0).
	394	*/
953192ba MD	395	static
	396	int visit_node_logical(struct filter_parser_ctx ctx, struct ir_op node)
	397	{
	398	int ret;
	399	struct logical_op insn;
	400	uint16_t skip_offset_loc;
	401	uint16_t target_loc;
	402
	403	/* Visit left child */
	404	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left);
	405	if (ret)
	406	return ret;
8cf9540a MD	407	/* Cast to s64 if float or field ref */
	408	if (node->u.binary.left->data_type == IR_DATA_FIELD_REF
	409	\|\| node->u.binary.left->data_type == IR_DATA_FLOAT) {
	410	struct cast_op cast_insn;
	411
29fefef8 MD	412	if (node->u.binary.left->data_type == IR_DATA_FIELD_REF) {
	413	cast_insn.op = FILTER_OP_CAST_TO_S64;
	414	} else {
	415	cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
	416	}
8cf9540a MD	417	ret = bytecode_push(&ctx->bytecode, &cast_insn,
	418	1, sizeof(cast_insn));
	419	if (ret)
	420	return ret;
	421	}
953192ba MD	422	switch (node->u.logical.type) {
	423	default:
	424	fprintf(stderr, "[error] Unknown node type in %s\n",
	425	__func__);
	426	return -EINVAL;
	427
	428	case AST_OP_AND:
	429	insn.op = FILTER_OP_AND;
	430	break;
	431	case AST_OP_OR:
	432	insn.op = FILTER_OP_OR;
	433	break;
	434	}
	435	insn.skip_offset = (uint16_t) -1UL; /* Temporary */
	436	ret = bytecode_push_logical(&ctx->bytecode, &insn, 1, sizeof(insn),
	437	&skip_offset_loc);
	438	if (ret)
	439	return ret;
	440	/* Visit right child */
	441	ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right);
	442	if (ret)
	443	return ret;
8cf9540a MD	444	/* Cast to s64 if float or field ref */
	445	if (node->u.binary.right->data_type == IR_DATA_FIELD_REF
	446	\|\| node->u.binary.right->data_type == IR_DATA_FLOAT) {
	447	struct cast_op cast_insn;
	448
29fefef8 MD	449	if (node->u.binary.right->data_type == IR_DATA_FIELD_REF) {
	450	cast_insn.op = FILTER_OP_CAST_TO_S64;
	451	} else {
	452	cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
	453	}
8cf9540a MD	454	ret = bytecode_push(&ctx->bytecode, &cast_insn,
	455	1, sizeof(cast_insn));
	456	if (ret)
	457	return ret;
	458	}
953192ba MD	459	/* We now know where the logical op can skip. */
	460	target_loc = (uint16_t) bytecode_get_len(&ctx->bytecode->b);
	461	ret = bytecode_patch(&ctx->bytecode,
	462	&target_loc, /* Offset to jump to */
	463	skip_offset_loc, /* Where to patch */
	464	sizeof(uint16_t));
	465	return ret;
	466	}
	467
	468	/*
	469	* Postorder traversal of the tree. We need the children result before
	470	* we can evaluate the parent.
	471	*/
	472	static
	473	int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx,
	474	struct ir_op *node)
	475	{
	476	switch (node->op) {
	477	case IR_OP_UNKNOWN:
	478	default:
	479	fprintf(stderr, "[error] Unknown node type in %s\n",
	480	__func__);
	481	return -EINVAL;
	482
	483	case IR_OP_ROOT:
	484	return visit_node_root(ctx, node);
	485	case IR_OP_LOAD:
	486	return visit_node_load(ctx, node);
	487	case IR_OP_UNARY:
	488	return visit_node_unary(ctx, node);
	489	case IR_OP_BINARY:
	490	return visit_node_binary(ctx, node);
	491	case IR_OP_LOGICAL:
	492	return visit_node_logical(ctx, node);
	493	}
	494	}
	495
d00c599e	496	__attribute__((visibility("hidden")))
953192ba MD	497	void filter_bytecode_free(struct filter_parser_ctx *ctx)
	498	{
	499	free(ctx->bytecode);
	500	ctx->bytecode = NULL;
	501	free(ctx->bytecode_reloc);
	502	ctx->bytecode_reloc = NULL;
	503	}
	504
d00c599e	505	__attribute__((visibility("hidden")))
953192ba MD	506	int filter_visitor_bytecode_generate(struct filter_parser_ctx *ctx)
	507	{
	508	int ret;
	509
	510	ret = bytecode_init(&ctx->bytecode);
	511	if (ret)
	512	return ret;
	513	ret = bytecode_init(&ctx->bytecode_reloc);
	514	if (ret)
	515	goto error;
	516	ret = recursive_visit_gen_bytecode(ctx, ctx->ir_root);
	517	if (ret)
	518	goto error;
	519
	520	/* Finally, append symbol table to bytecode */
	521	ctx->bytecode->b.reloc_table_offset = bytecode_get_len(&ctx->bytecode->b);
	522	return bytecode_push(&ctx->bytecode, ctx->bytecode_reloc->b.data,
	523	1, bytecode_get_len(&ctx->bytecode_reloc->b));
	524
	525	error:
	526	filter_bytecode_free(ctx);
	527	return ret;
	528	}