linux-vybrid_public/tools/perf/util/annotate.c

/*
 * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
 *
 * Parts came from builtin-annotate.c, see those files for further
 * copyright notes.
 *
 * Released under the GPL v2. (and only v2, not any later version)
 */

#include "util.h"
#include "build-id.h"
#include "color.h"
#include "cache.h"
#include "symbol.h"
#include "debug.h"
#include "annotate.h"
#include <pthread.h>

const char 	*disassembler_style;

static int ins__raw_scnprintf(struct ins *ins, char *bf, size_t size,
			      struct ins_operands *ops)
{
	return scnprintf(bf, size, "%-6.6s %s", ins->name, ops->raw);
}

int ins__scnprintf(struct ins *ins, char *bf, size_t size,
		  struct ins_operands *ops)
{
	if (ins->ops->scnprintf)
		return ins->ops->scnprintf(ins, bf, size, ops);

	return ins__raw_scnprintf(ins, bf, size, ops);
}

static int call__parse(struct ins_operands *ops)
{
	char *endptr, *tok, *name;

	ops->target.addr = strtoull(ops->raw, &endptr, 16);

	name = strchr(endptr, '<');
	if (name == NULL)
		goto indirect_call;

	name++;

	tok = strchr(name, '>');
	if (tok == NULL)
		return -1;

	*tok = '\0';
	ops->target.name = strdup(name);
	*tok = '>';

	return ops->target.name == NULL ? -1 : 0;

indirect_call:
	tok = strchr(endptr, '*');
	if (tok == NULL)
		return -1;

	ops->target.addr = strtoull(tok + 1, NULL, 16);
	return 0;
}

static int call__scnprintf(struct ins *ins, char *bf, size_t size,
			   struct ins_operands *ops)
{
	if (ops->target.name)
		return scnprintf(bf, size, "%-6.6s %s", ins->name, ops->target.name);

	return scnprintf(bf, size, "%-6.6s *%" PRIx64, ins->name, ops->target.addr);
}

static struct ins_ops call_ops = {
	.parse	   = call__parse,
	.scnprintf = call__scnprintf,
};

bool ins__is_call(const struct ins *ins)
{
	return ins->ops == &call_ops;
}

static int jump__parse(struct ins_operands *ops)
{
	const char *s = strchr(ops->raw, '+');

	ops->target.addr = strtoll(ops->raw, NULL, 16);

	if (s++ != NULL)
		ops->target.offset = strtoll(s, NULL, 16);
	else
		ops->target.offset = UINT64_MAX;

	return 0;
}

static int jump__scnprintf(struct ins *ins, char *bf, size_t size,
			   struct ins_operands *ops)
{
	return scnprintf(bf, size, "%-6.6s %" PRIx64, ins->name, ops->target.offset);
}

static struct ins_ops jump_ops = {
	.parse	   = jump__parse,
	.scnprintf = jump__scnprintf,
};

bool ins__is_jump(const struct ins *ins)
{
	return ins->ops == &jump_ops;
}

/*
 * Must be sorted by name!
 */
static struct ins instructions[] = {
	{ .name = "call",  .ops  = &call_ops, },
	{ .name = "callq", .ops  = &call_ops, },
	{ .name = "ja",	   .ops  = &jump_ops, },
	{ .name = "jae",   .ops  = &jump_ops, },
	{ .name = "jb",	   .ops  = &jump_ops, },
	{ .name = "jbe",   .ops  = &jump_ops, },
	{ .name = "jc",	   .ops  = &jump_ops, },
	{ .name = "jcxz",  .ops  = &jump_ops, },
	{ .name = "je",	   .ops  = &jump_ops, },
	{ .name = "jecxz", .ops  = &jump_ops, },
	{ .name = "jg",	   .ops  = &jump_ops, },
	{ .name = "jge",   .ops  = &jump_ops, },
	{ .name = "jl",    .ops  = &jump_ops, },
	{ .name = "jle",   .ops  = &jump_ops, },
	{ .name = "jmp",   .ops  = &jump_ops, },
	{ .name = "jmpq",  .ops  = &jump_ops, },
	{ .name = "jna",   .ops  = &jump_ops, },
	{ .name = "jnae",  .ops  = &jump_ops, },
	{ .name = "jnb",   .ops  = &jump_ops, },
	{ .name = "jnbe",  .ops  = &jump_ops, },
	{ .name = "jnc",   .ops  = &jump_ops, },
	{ .name = "jne",   .ops  = &jump_ops, },
	{ .name = "jng",   .ops  = &jump_ops, },
	{ .name = "jnge",  .ops  = &jump_ops, },
	{ .name = "jnl",   .ops  = &jump_ops, },
	{ .name = "jnle",  .ops  = &jump_ops, },
	{ .name = "jno",   .ops  = &jump_ops, },
	{ .name = "jnp",   .ops  = &jump_ops, },
	{ .name = "jns",   .ops  = &jump_ops, },
	{ .name = "jnz",   .ops  = &jump_ops, },
	{ .name = "jo",	   .ops  = &jump_ops, },
	{ .name = "jp",	   .ops  = &jump_ops, },
	{ .name = "jpe",   .ops  = &jump_ops, },
	{ .name = "jpo",   .ops  = &jump_ops, },
	{ .name = "jrcxz", .ops  = &jump_ops, },
	{ .name = "js",	   .ops  = &jump_ops, },
	{ .name = "jz",	   .ops  = &jump_ops, },
};

static int ins__cmp(const void *name, const void *insp)
{
	const struct ins *ins = insp;

	return strcmp(name, ins->name);
}

static struct ins *ins__find(const char *name)
{
	const int nmemb = ARRAY_SIZE(instructions);

	return bsearch(name, instructions, nmemb, sizeof(struct ins), ins__cmp);
}

int symbol__annotate_init(struct map *map __used, struct symbol *sym)
{
	struct annotation *notes = symbol__annotation(sym);
	pthread_mutex_init(&notes->lock, NULL);
	return 0;
}

int symbol__alloc_hist(struct symbol *sym)
{
	struct annotation *notes = symbol__annotation(sym);
	const size_t size = symbol__size(sym);
	size_t sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(u64));

	notes->src = zalloc(sizeof(*notes->src) + symbol_conf.nr_events * sizeof_sym_hist);
	if (notes->src == NULL)
		return -1;
	notes->src->sizeof_sym_hist = sizeof_sym_hist;
	notes->src->nr_histograms   = symbol_conf.nr_events;
	INIT_LIST_HEAD(&notes->src->source);
	return 0;
}

void symbol__annotate_zero_histograms(struct symbol *sym)
{
	struct annotation *notes = symbol__annotation(sym);

	pthread_mutex_lock(&notes->lock);
	if (notes->src != NULL)
		memset(notes->src->histograms, 0,
		       notes->src->nr_histograms * notes->src->sizeof_sym_hist);
	pthread_mutex_unlock(&notes->lock);
}

int symbol__inc_addr_samples(struct symbol *sym, struct map *map,
			     int evidx, u64 addr)
{
	unsigned offset;
	struct annotation *notes;
	struct sym_hist *h;

	notes = symbol__annotation(sym);
	if (notes->src == NULL)
		return -ENOMEM;

	pr_debug3("%s: addr=%#" PRIx64 "\n", __func__, map->unmap_ip(map, addr));

	if (addr < sym->start || addr > sym->end)
		return -ERANGE;

	offset = addr - sym->start;
	h = annotation__histogram(notes, evidx);
	h->sum++;
	h->addr[offset]++;

	pr_debug3("%#" PRIx64 " %s: period++ [addr: %#" PRIx64 ", %#" PRIx64
		  ", evidx=%d] => %" PRIu64 "\n", sym->start, sym->name,
		  addr, addr - sym->start, evidx, h->addr[offset]);
	return 0;
}

static void disasm_line__init_ins(struct disasm_line *dl)
{
	dl->ins = ins__find(dl->name);

	if (dl->ins == NULL)
		return;

	if (!dl->ins->ops)
		return;

	if (dl->ins->ops->parse)
		dl->ins->ops->parse(&dl->ops);
}

static struct disasm_line *disasm_line__new(s64 offset, char *line, size_t privsize)
{
	struct disasm_line *dl = zalloc(sizeof(*dl) + privsize);

	if (dl != NULL) {
		dl->offset = offset;
		dl->line = strdup(line);
		if (dl->line == NULL)
			goto out_delete;

		if (offset != -1) {
			char *name = dl->line, tmp;

			while (isspace(name[0]))
				++name;

			if (name[0] == '\0')
				goto out_delete;

			dl->ops.raw = name + 1;

			while (dl->ops.raw[0] != '\0' &&
			       !isspace(dl->ops.raw[0]))
				++dl->ops.raw;

			tmp = dl->ops.raw[0];
			dl->ops.raw[0] = '\0';
			dl->name = strdup(name);

			if (dl->name == NULL)
				goto out_free_line;

			dl->ops.raw[0] = tmp;

			if (dl->ops.raw[0] != '\0') {
				dl->ops.raw++;
				while (isspace(dl->ops.raw[0]))
					++dl->ops.raw;
			}

			disasm_line__init_ins(dl);
		}
	}

	return dl;

out_free_line:
	free(dl->line);
out_delete:
	free(dl);
	return NULL;
}

void disasm_line__free(struct disasm_line *dl)
{
	free(dl->line);
	free(dl->name);
	free(dl->ops.target.name);
	free(dl);
}

int disasm_line__scnprintf(struct disasm_line *dl, char *bf, size_t size, bool raw)
{
	if (raw || !dl->ins)
		return scnprintf(bf, size, "%-6.6s %s", dl->name, dl->ops.raw);

	return ins__scnprintf(dl->ins, bf, size, &dl->ops);
}

static void disasm__add(struct list_head *head, struct disasm_line *line)
{
	list_add_tail(&line->node, head);
}

struct disasm_line *disasm__get_next_ip_line(struct list_head *head, struct disasm_line *pos)
{
	list_for_each_entry_continue(pos, head, node)
		if (pos->offset >= 0)
			return pos;

	return NULL;
}

static int disasm_line__print(struct disasm_line *dl, struct symbol *sym, u64 start,
		      int evidx, u64 len, int min_pcnt, int printed,
		      int max_lines, struct disasm_line *queue)
{
	static const char *prev_line;
	static const char *prev_color;

	if (dl->offset != -1) {
		const char *path = NULL;
		unsigned int hits = 0;
		double percent = 0.0;
		const char *color;
		struct annotation *notes = symbol__annotation(sym);
		struct source_line *src_line = notes->src->lines;
		struct sym_hist *h = annotation__histogram(notes, evidx);
		s64 offset = dl->offset;
		const u64 addr = start + offset;
		struct disasm_line *next;

		next = disasm__get_next_ip_line(&notes->src->source, dl);

		while (offset < (s64)len &&
		       (next == NULL || offset < next->offset)) {
			if (src_line) {
				if (path == NULL)
					path = src_line[offset].path;
				percent += src_line[offset].percent;
			} else
				hits += h->addr[offset];

			++offset;
		}

		if (src_line == NULL && h->sum)
			percent = 100.0 * hits / h->sum;

		if (percent < min_pcnt)
			return -1;

		if (max_lines && printed >= max_lines)
			return 1;

		if (queue != NULL) {
			list_for_each_entry_from(queue, &notes->src->source, node) {
				if (queue == dl)
					break;
				disasm_line__print(queue, sym, start, evidx, len,
						    0, 0, 1, NULL);
			}
		}

		color = get_percent_color(percent);

		/*
		 * Also color the filename and line if needed, with
		 * the same color than the percentage. Don't print it
		 * twice for close colored addr with the same filename:line
		 */
		if (path) {
			if (!prev_line || strcmp(prev_line, path)
				       || color != prev_color) {
				color_fprintf(stdout, color, " %s", path);
				prev_line = path;
				prev_color = color;
			}
		}

		color_fprintf(stdout, color, " %7.2f", percent);
		printf(" :	");
		color_fprintf(stdout, PERF_COLOR_MAGENTA, "  %" PRIx64 ":", addr);
		color_fprintf(stdout, PERF_COLOR_BLUE, "%s\n", dl->line);
	} else if (max_lines && printed >= max_lines)
		return 1;
	else {
		if (queue)
			return -1;

		if (!*dl->line)
			printf("         :\n");
		else
			printf("         :	%s\n", dl->line);
	}

	return 0;
}

static int symbol__parse_objdump_line(struct symbol *sym, struct map *map,
				      FILE *file, size_t privsize)
{
	struct annotation *notes = symbol__annotation(sym);
	struct disasm_line *dl;
	char *line = NULL, *parsed_line, *tmp, *tmp2, *c;
	size_t line_len;
	s64 line_ip, offset = -1;

	if (getline(&line, &line_len, file) < 0)
		return -1;

	if (!line)
		return -1;

	while (line_len != 0 && isspace(line[line_len - 1]))
		line[--line_len] = '\0';

	c = strchr(line, '\n');
	if (c)
		*c = 0;

	line_ip = -1;
	parsed_line = line;

	/*
	 * Strip leading spaces:
	 */
	tmp = line;
	while (*tmp) {
		if (*tmp != ' ')
			break;
		tmp++;
	}

	if (*tmp) {
		/*
		 * Parse hexa addresses followed by ':'
		 */
		line_ip = strtoull(tmp, &tmp2, 16);
		if (*tmp2 != ':' || tmp == tmp2 || tmp2[1] == '\0')
			line_ip = -1;
	}

	if (line_ip != -1) {
		u64 start = map__rip_2objdump(map, sym->start),
		    end = map__rip_2objdump(map, sym->end);

		offset = line_ip - start;
		if (offset < 0 || (u64)line_ip > end)
			offset = -1;
		else
			parsed_line = tmp2 + 1;
	}

	dl = disasm_line__new(offset, parsed_line, privsize);
	free(line);

	if (dl == NULL)
		return -1;

	disasm__add(&notes->src->source, dl);

	return 0;
}

int symbol__annotate(struct symbol *sym, struct map *map, size_t privsize)
{
	struct dso *dso = map->dso;
	char *filename = dso__build_id_filename(dso, NULL, 0);
	bool free_filename = true;
	char command[PATH_MAX * 2];
	FILE *file;
	int err = 0;
	char symfs_filename[PATH_MAX];

	if (filename) {
		snprintf(symfs_filename, sizeof(symfs_filename), "%s%s",
			 symbol_conf.symfs, filename);
	}

	if (filename == NULL) {
		if (dso->has_build_id) {
			pr_err("Can't annotate %s: not enough memory\n",
			       sym->name);
			return -ENOMEM;
		}
		goto fallback;
	} else if (readlink(symfs_filename, command, sizeof(command)) < 0 ||
		   strstr(command, "[kernel.kallsyms]") ||
		   access(symfs_filename, R_OK)) {
		free(filename);
fallback:
		/*
		 * If we don't have build-ids or the build-id file isn't in the
		 * cache, or is just a kallsyms file, well, lets hope that this
		 * DSO is the same as when 'perf record' ran.
		 */
		filename = dso->long_name;
		snprintf(symfs_filename, sizeof(symfs_filename), "%s%s",
			 symbol_conf.symfs, filename);
		free_filename = false;
	}

	if (dso->symtab_type == SYMTAB__KALLSYMS) {
		char bf[BUILD_ID_SIZE * 2 + 16] = " with build id ";
		char *build_id_msg = NULL;

		if (dso->annotate_warned)
			goto out_free_filename;

		if (dso->has_build_id) {
			build_id__sprintf(dso->build_id,
					  sizeof(dso->build_id), bf + 15);
			build_id_msg = bf;
		}
		err = -ENOENT;
		dso->annotate_warned = 1;
		pr_err("Can't annotate %s:\n\n"
		       "No vmlinux file%s\nwas found in the path.\n\n"
		       "Please use:\n\n"
		       "  perf buildid-cache -av vmlinux\n\n"
		       "or:\n\n"
		       "  --vmlinux vmlinux\n",
		       sym->name, build_id_msg ?: "");
		goto out_free_filename;
	}

	pr_debug("%s: filename=%s, sym=%s, start=%#" PRIx64 ", end=%#" PRIx64 "\n", __func__,
		 filename, sym->name, map->unmap_ip(map, sym->start),
		 map->unmap_ip(map, sym->end));

	pr_debug("annotating [%p] %30s : [%p] %30s\n",
		 dso, dso->long_name, sym, sym->name);

	snprintf(command, sizeof(command),
		 "objdump %s%s --start-address=0x%016" PRIx64
		 " --stop-address=0x%016" PRIx64
		 " -d %s %s -C %s|grep -v %s|expand",
		 disassembler_style ? "-M " : "",
		 disassembler_style ? disassembler_style : "",
		 map__rip_2objdump(map, sym->start),
		 map__rip_2objdump(map, sym->end+1),
		 symbol_conf.annotate_asm_raw ? "" : "--no-show-raw",
		 symbol_conf.annotate_src ? "-S" : "",
		 symfs_filename, filename);

	pr_debug("Executing: %s\n", command);

	file = popen(command, "r");
	if (!file)
		goto out_free_filename;

	while (!feof(file))
		if (symbol__parse_objdump_line(sym, map, file, privsize) < 0)
			break;

	pclose(file);
out_free_filename:
	if (free_filename)
		free(filename);
	return err;
}

static void insert_source_line(struct rb_root *root, struct source_line *src_line)
{
	struct source_line *iter;
	struct rb_node **p = &root->rb_node;
	struct rb_node *parent = NULL;

	while (*p != NULL) {
		parent = *p;
		iter = rb_entry(parent, struct source_line, node);

		if (src_line->percent > iter->percent)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}

	rb_link_node(&src_line->node, parent, p);
	rb_insert_color(&src_line->node, root);
}

static void symbol__free_source_line(struct symbol *sym, int len)
{
	struct annotation *notes = symbol__annotation(sym);
	struct source_line *src_line = notes->src->lines;
	int i;

	for (i = 0; i < len; i++)
		free(src_line[i].path);

	free(src_line);
	notes->src->lines = NULL;
}

/* Get the filename:line for the colored entries */
static int symbol__get_source_line(struct symbol *sym, struct map *map,
				   int evidx, struct rb_root *root, int len,
				   const char *filename)
{
	u64 start;
	int i;
	char cmd[PATH_MAX * 2];
	struct source_line *src_line;
	struct annotation *notes = symbol__annotation(sym);
	struct sym_hist *h = annotation__histogram(notes, evidx);

	if (!h->sum)
		return 0;

	src_line = notes->src->lines = calloc(len, sizeof(struct source_line));
	if (!notes->src->lines)
		return -1;

	start = map__rip_2objdump(map, sym->start);

	for (i = 0; i < len; i++) {
		char *path = NULL;
		size_t line_len;
		u64 offset;
		FILE *fp;

		src_line[i].percent = 100.0 * h->addr[i] / h->sum;
		if (src_line[i].percent <= 0.5)
			continue;

		offset = start + i;
		sprintf(cmd, "addr2line -e %s %016" PRIx64, filename, offset);
		fp = popen(cmd, "r");
		if (!fp)
			continue;

		if (getline(&path, &line_len, fp) < 0 || !line_len)
			goto next;

		src_line[i].path = malloc(sizeof(char) * line_len + 1);
		if (!src_line[i].path)
			goto next;

		strcpy(src_line[i].path, path);
		insert_source_line(root, &src_line[i]);

	next:
		pclose(fp);
	}

	return 0;
}

static void print_summary(struct rb_root *root, const char *filename)
{
	struct source_line *src_line;
	struct rb_node *node;

	printf("\nSorted summary for file %s\n", filename);
	printf("----------------------------------------------\n\n");

	if (RB_EMPTY_ROOT(root)) {
		printf(" Nothing higher than %1.1f%%\n", MIN_GREEN);
		return;
	}

	node = rb_first(root);
	while (node) {
		double percent;
		const char *color;
		char *path;

		src_line = rb_entry(node, struct source_line, node);
		percent = src_line->percent;
		color = get_percent_color(percent);
		path = src_line->path;

		color_fprintf(stdout, color, " %7.2f %s", percent, path);
		node = rb_next(node);
	}
}

static void symbol__annotate_hits(struct symbol *sym, int evidx)
{
	struct annotation *notes = symbol__annotation(sym);
	struct sym_hist *h = annotation__histogram(notes, evidx);
	u64 len = symbol__size(sym), offset;

	for (offset = 0; offset < len; ++offset)
		if (h->addr[offset] != 0)
			printf("%*" PRIx64 ": %" PRIu64 "\n", BITS_PER_LONG / 2,
			       sym->start + offset, h->addr[offset]);
	printf("%*s: %" PRIu64 "\n", BITS_PER_LONG / 2, "h->sum", h->sum);
}

int symbol__annotate_printf(struct symbol *sym, struct map *map, int evidx,
			    bool full_paths, int min_pcnt, int max_lines,
			    int context)
{
	struct dso *dso = map->dso;
	const char *filename = dso->long_name, *d_filename;
	struct annotation *notes = symbol__annotation(sym);
	struct disasm_line *pos, *queue = NULL;
	u64 start = map__rip_2objdump(map, sym->start);
	int printed = 2, queue_len = 0;
	int more = 0;
	u64 len;

	if (full_paths)
		d_filename = filename;
	else
		d_filename = basename(filename);

	len = symbol__size(sym);

	printf(" Percent |	Source code & Disassembly of %s\n", d_filename);
	printf("------------------------------------------------\n");

	if (verbose)
		symbol__annotate_hits(sym, evidx);

	list_for_each_entry(pos, &notes->src->source, node) {
		if (context && queue == NULL) {
			queue = pos;
			queue_len = 0;
		}

		switch (disasm_line__print(pos, sym, start, evidx, len,
					    min_pcnt, printed, max_lines,
					    queue)) {
		case 0:
			++printed;
			if (context) {
				printed += queue_len;
				queue = NULL;
				queue_len = 0;
			}
			break;
		case 1:
			/* filtered by max_lines */
			++more;
			break;
		case -1:
		default:
			/*
			 * Filtered by min_pcnt or non IP lines when
			 * context != 0
			 */
			if (!context)
				break;
			if (queue_len == context)
				queue = list_entry(queue->node.next, typeof(*queue), node);
			else
				++queue_len;
			break;
		}
	}

	return more;
}

void symbol__annotate_zero_histogram(struct symbol *sym, int evidx)
{
	struct annotation *notes = symbol__annotation(sym);
	struct sym_hist *h = annotation__histogram(notes, evidx);

	memset(h, 0, notes->src->sizeof_sym_hist);
}

void symbol__annotate_decay_histogram(struct symbol *sym, int evidx)
{
	struct annotation *notes = symbol__annotation(sym);
	struct sym_hist *h = annotation__histogram(notes, evidx);
	int len = symbol__size(sym), offset;

	h->sum = 0;
	for (offset = 0; offset < len; ++offset) {
		h->addr[offset] = h->addr[offset] * 7 / 8;
		h->sum += h->addr[offset];
	}
}

void disasm__purge(struct list_head *head)
{
	struct disasm_line *pos, *n;

	list_for_each_entry_safe(pos, n, head, node) {
		list_del(&pos->node);
		disasm_line__free(pos);
	}
}

static size_t disasm_line__fprintf(struct disasm_line *dl, FILE *fp)
{
	size_t printed;

	if (dl->offset == -1)
		return fprintf(fp, "%s\n", dl->line);

	printed = fprintf(fp, "%#" PRIx64 " %s", dl->offset, dl->name);

	if (dl->ops.raw[0] != '\0') {
		printed += fprintf(fp, "%.*s %s\n", 6 - (int)printed, " ",
				   dl->ops.raw);
	}

	return printed + fprintf(fp, "\n");
}

size_t disasm__fprintf(struct list_head *head, FILE *fp)
{
	struct disasm_line *pos;
	size_t printed = 0;

	list_for_each_entry(pos, head, node)
		printed += disasm_line__fprintf(pos, fp);

	return printed;
}

int symbol__tty_annotate(struct symbol *sym, struct map *map, int evidx,
			 bool print_lines, bool full_paths, int min_pcnt,
			 int max_lines)
{
	struct dso *dso = map->dso;
	const char *filename = dso->long_name;
	struct rb_root source_line = RB_ROOT;
	u64 len;

	if (symbol__annotate(sym, map, 0) < 0)
		return -1;

	len = symbol__size(sym);

	if (print_lines) {
		symbol__get_source_line(sym, map, evidx, &source_line,
					len, filename);
		print_summary(&source_line, filename);
	}

	symbol__annotate_printf(sym, map, evidx, full_paths,
				min_pcnt, max_lines, 0);
	if (print_lines)
		symbol__free_source_line(sym, len);

	disasm__purge(&symbol__annotation(sym)->src->source);

	return 0;
}