tools/lib/traceevent/event-parse.c

/*
 * Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License (not later!)
 *
 * This program 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 program; if not,  see <http://www.gnu.org/licenses>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  The parts for function graph printing was taken and modified from the
 *  Linux Kernel that were written by
 *    - Copyright (C) 2009  Frederic Weisbecker,
 *  Frederic Weisbecker gave his permission to relicense the code to
 *  the Lesser General Public License.
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <ctype.h>
#include <errno.h>
#include <stdint.h>
#include <limits.h>

#include "event-parse.h"
#include "event-utils.h"

static const char *input_buf;
static unsigned long long input_buf_ptr;
static unsigned long long input_buf_siz;

static int is_flag_field;
static int is_symbolic_field;

static int show_warning = 1;

#define do_warning(fmt, ...)				\
	do {						\
		if (show_warning)			\
			warning(fmt, ##__VA_ARGS__);	\
	} while (0)

static void init_input_buf(const char *buf, unsigned long long size)
{
	input_buf = buf;
	input_buf_siz = size;
	input_buf_ptr = 0;
}

const char *pevent_get_input_buf(void)
{
	return input_buf;
}

unsigned long long pevent_get_input_buf_ptr(void)
{
	return input_buf_ptr;
}

struct event_handler {
	struct event_handler		*next;
	int				id;
	const char			*sys_name;
	const char			*event_name;
	pevent_event_handler_func	func;
	void				*context;
};

struct pevent_func_params {
	struct pevent_func_params	*next;
	enum pevent_func_arg_type	type;
};

struct pevent_function_handler {
	struct pevent_function_handler	*next;
	enum pevent_func_arg_type	ret_type;
	char				*name;
	pevent_func_handler		func;
	struct pevent_func_params	*params;
	int				nr_args;
};

static unsigned long long
process_defined_func(struct trace_seq *s, void *data, int size,
		     struct event_format *event, struct print_arg *arg);

static void free_func_handle(struct pevent_function_handler *func);

/**
 * pevent_buffer_init - init buffer for parsing
 * @buf: buffer to parse
 * @size: the size of the buffer
 *
 * For use with pevent_read_token(), this initializes the internal
 * buffer that pevent_read_token() will parse.
 */
void pevent_buffer_init(const char *buf, unsigned long long size)
{
	init_input_buf(buf, size);
}

void breakpoint(void)
{
	static int x;
	x++;
}

struct print_arg *alloc_arg(void)
{
	return calloc(1, sizeof(struct print_arg));
}

struct cmdline {
	char *comm;
	int pid;
};

static int cmdline_cmp(const void *a, const void *b)
{
	const struct cmdline *ca = a;
	const struct cmdline *cb = b;

	if (ca->pid < cb->pid)
		return -1;
	if (ca->pid > cb->pid)
		return 1;

	return 0;
}

struct cmdline_list {
	struct cmdline_list	*next;
	char			*comm;
	int			pid;
};

static int cmdline_init(struct pevent *pevent)
{
	struct cmdline_list *cmdlist = pevent->cmdlist;
	struct cmdline_list *item;
	struct cmdline *cmdlines;
	int i;

	cmdlines = malloc(sizeof(*cmdlines) * pevent->cmdline_count);
	if (!cmdlines)
		return -1;

	i = 0;
	while (cmdlist) {
		cmdlines[i].pid = cmdlist->pid;
		cmdlines[i].comm = cmdlist->comm;
		i++;
		item = cmdlist;
		cmdlist = cmdlist->next;
		free(item);
	}

	qsort(cmdlines, pevent->cmdline_count, sizeof(*cmdlines), cmdline_cmp);

	pevent->cmdlines = cmdlines;
	pevent->cmdlist = NULL;

	return 0;
}

static const char *find_cmdline(struct pevent *pevent, int pid)
{
	const struct cmdline *comm;
	struct cmdline key;

	if (!pid)
		return "<idle>";

	if (!pevent->cmdlines && cmdline_init(pevent))
		return "<not enough memory for cmdlines!>";

	key.pid = pid;

	comm = bsearch(&key, pevent->cmdlines, pevent->cmdline_count,
		       sizeof(*pevent->cmdlines), cmdline_cmp);

	if (comm)
		return comm->comm;
	return "<...>";
}

/**
 * pevent_pid_is_registered - return if a pid has a cmdline registered
 * @pevent: handle for the pevent
 * @pid: The pid to check if it has a cmdline registered with.
 *
 * Returns 1 if the pid has a cmdline mapped to it
 * 0 otherwise.
 */
int pevent_pid_is_registered(struct pevent *pevent, int pid)
{
	const struct cmdline *comm;
	struct cmdline key;

	if (!pid)
		return 1;

	if (!pevent->cmdlines && cmdline_init(pevent))
		return 0;

	key.pid = pid;

	comm = bsearch(&key, pevent->cmdlines, pevent->cmdline_count,
		       sizeof(*pevent->cmdlines), cmdline_cmp);

	if (comm)
		return 1;
	return 0;
}

/*
 * If the command lines have been converted to an array, then
 * we must add this pid. This is much slower than when cmdlines
 * are added before the array is initialized.
 */
static int add_new_comm(struct pevent *pevent, const char *comm, int pid)
{
	struct cmdline *cmdlines = pevent->cmdlines;
	const struct cmdline *cmdline;
	struct cmdline key;

	if (!pid)
		return 0;

	/* avoid duplicates */
	key.pid = pid;

	cmdline = bsearch(&key, pevent->cmdlines, pevent->cmdline_count,
		       sizeof(*pevent->cmdlines), cmdline_cmp);
	if (cmdline) {
		errno = EEXIST;
		return -1;
	}

	cmdlines = realloc(cmdlines, sizeof(*cmdlines) * (pevent->cmdline_count + 1));
	if (!cmdlines) {
		errno = ENOMEM;
		return -1;
	}

	cmdlines[pevent->cmdline_count].comm = strdup(comm);
	if (!cmdlines[pevent->cmdline_count].comm) {
		free(cmdlines);
		errno = ENOMEM;
		return -1;
	}

	cmdlines[pevent->cmdline_count].pid = pid;
		
	if (cmdlines[pevent->cmdline_count].comm)
		pevent->cmdline_count++;

	qsort(cmdlines, pevent->cmdline_count, sizeof(*cmdlines), cmdline_cmp);
	pevent->cmdlines = cmdlines;

	return 0;
}

/**
 * pevent_register_comm - register a pid / comm mapping
 * @pevent: handle for the pevent
 * @comm: the command line to register
 * @pid: the pid to map the command line to
 *
 * This adds a mapping to search for command line names with
 * a given pid. The comm is duplicated.
 */
int pevent_register_comm(struct pevent *pevent, const char *comm, int pid)
{
	struct cmdline_list *item;

	if (pevent->cmdlines)
		return add_new_comm(pevent, comm, pid);

	item = malloc(sizeof(*item));
	if (!item)
		return -1;

	item->comm = strdup(comm);
	if (!item->comm) {
		free(item);
		return -1;
	}
	item->pid = pid;
	item->next = pevent->cmdlist;

	pevent->cmdlist = item;
	pevent->cmdline_count++;

	return 0;
}

struct func_map {
	unsigned long long		addr;
	char				*func;
	char				*mod;
};

struct func_list {
	struct func_list	*next;
	unsigned long long	addr;
	char			*func;
	char			*mod;
};

static int func_cmp(const void *a, const void *b)
{
	const struct func_map *fa = a;
	const struct func_map *fb = b;

	if (fa->addr < fb->addr)
		return -1;
	if (fa->addr > fb->addr)
		return 1;

	return 0;
}

/*
 * We are searching for a record in between, not an exact
 * match.
 */
static int func_bcmp(const void *a, const void *b)
{
	const struct func_map *fa = a;
	const struct func_map *fb = b;

	if ((fa->addr == fb->addr) ||

	    (fa->addr > fb->addr &&
	     fa->addr < (fb+1)->addr))
		return 0;

	if (fa->addr < fb->addr)
		return -1;

	return 1;
}

static int func_map_init(struct pevent *pevent)
{
	struct func_list *funclist;
	struct func_list *item;
	struct func_map *func_map;
	int i;

	func_map = malloc(sizeof(*func_map) * (pevent->func_count + 1));
	if (!func_map)
		return -1;

	funclist = pevent->funclist;

	i = 0;
	while (funclist) {
		func_map[i].func = funclist->func;
		func_map[i].addr = funclist->addr;
		func_map[i].mod = funclist->mod;
		i++;
		item = funclist;
		funclist = funclist->next;
		free(item);
	}

	qsort(func_map, pevent->func_count, sizeof(*func_map), func_cmp);

	/*
	 * Add a special record at the end.
	 */
	func_map[pevent->func_count].func = NULL;
	func_map[pevent->func_count].addr = 0;
	func_map[pevent->func_count].mod = NULL;

	pevent->func_map = func_map;
	pevent->funclist = NULL;

	return 0;
}

static struct func_map *
find_func(struct pevent *pevent, unsigned long long addr)
{
	struct func_map *func;
	struct func_map key;

	if (!pevent->func_map)
		func_map_init(pevent);

	key.addr = addr;

	func = bsearch(&key, pevent->func_map, pevent->func_count,
		       sizeof(*pevent->func_map), func_bcmp);

	return func;
}

/**
 * pevent_find_function - find a function by a given address
 * @pevent: handle for the pevent
 * @addr: the address to find the function with
 *
 * Returns a pointer to the function stored that has the given
 * address. Note, the address does not have to be exact, it
 * will select the function that would contain the address.
 */
const char *pevent_find_function(struct pevent *pevent, unsigned long long addr)
{
	struct func_map *map;

	map = find_func(pevent, addr);
	if (!map)
		return NULL;

	return map->func;
}

/**
 * pevent_find_function_address - find a function address by a given address
 * @pevent: handle for the pevent
 * @addr: the address to find the function with
 *
 * Returns the address the function starts at. This can be used in
 * conjunction with pevent_find_function to print both the function
 * name and the function offset.
 */
unsigned long long
pevent_find_function_address(struct pevent *pevent, unsigned long long addr)
{
	struct func_map *map;

	map = find_func(pevent, addr);
	if (!map)
		return 0;

	return map->addr;
}

/**
 * pevent_register_function - register a function with a given address
 * @pevent: handle for the pevent
 * @function: the function name to register
 * @addr: the address the function starts at
 * @mod: the kernel module the function may be in (NULL for none)
 *
 * This registers a function name with an address and module.
 * The @func passed in is duplicated.
 */
int pevent_register_function(struct pevent *pevent, char *func,
			     unsigned long long addr, char *mod)
{
	struct func_list *item = malloc(sizeof(*item));

	if (!item)
		return -1;

	item->next = pevent->funclist;
	item->func = strdup(func);
	if (!item->func)
		goto out_free;

	if (mod) {
		item->mod = strdup(mod);
		if (!item->mod)
			goto out_free_func;
	} else
		item->mod = NULL;
	item->addr = addr;

	pevent->funclist = item;
	pevent->func_count++;

	return 0;

out_free_func:
	free(item->func);
	item->func = NULL;
out_free:
	free(item);
	errno = ENOMEM;
	return -1;
}

/**
 * pevent_print_funcs - print out the stored functions
 * @pevent: handle for the pevent
 *
 * This prints out the stored functions.
 */
void pevent_print_funcs(struct pevent *pevent)
{
	int i;

	if (!pevent->func_map)
		func_map_init(pevent);

	for (i = 0; i < (int)pevent->func_count; i++) {
		printf("%016llx %s",
		       pevent->func_map[i].addr,
		       pevent->func_map[i].func);
		if (pevent->func_map[i].mod)
			printf(" [%s]\n", pevent->func_map[i].mod);
		else
			printf("\n");
	}
}

struct printk_map {
	unsigned long long		addr;
	char				*printk;
};

struct printk_list {
	struct printk_list	*next;
	unsigned long long	addr;
	char			*printk;
};

static int printk_cmp(const void *a, const void *b)
{
	const struct printk_map *pa = a;
	const struct printk_map *pb = b;

	if (pa->addr < pb->addr)
		return -1;
	if (pa->addr > pb->addr)
		return 1;

	return 0;
}

static int printk_map_init(struct pevent *pevent)
{
	struct printk_list *printklist;
	struct printk_list *item;
	struct printk_map *printk_map;
	int i;

	printk_map = malloc(sizeof(*printk_map) * (pevent->printk_count + 1));
	if (!printk_map)
		return -1;

	printklist = pevent->printklist;

	i = 0;
	while (printklist) {
		printk_map[i].printk = printklist->printk;
		printk_map[i].addr = printklist->addr;
		i++;
		item = printklist;
		printklist = printklist->next;
		free(item);
	}

	qsort(printk_map, pevent->printk_count, sizeof(*printk_map), printk_cmp);

	pevent->printk_map = printk_map;
	pevent->printklist = NULL;

	return 0;
}

static struct printk_map *
find_printk(struct pevent *pevent, unsigned long long addr)
{
	struct printk_map *printk;
	struct printk_map key;

	if (!pevent->printk_map && printk_map_init(pevent))
		return NULL;

	key.addr = addr;

	printk = bsearch(&key, pevent->printk_map, pevent->printk_count,
			 sizeof(*pevent->printk_map), printk_cmp);

	return printk;
}

/**
 * pevent_register_print_string - register a string by its address
 * @pevent: handle for the pevent
 * @fmt: the string format to register
 * @addr: the address the string was located at
 *
 * This registers a string by the address it was stored in the kernel.
 * The @fmt passed in is duplicated.
 */
int pevent_register_print_string(struct pevent *pevent, char *fmt,
				 unsigned long long addr)
{
	struct printk_list *item = malloc(sizeof(*item));

	if (!item)
		return -1;

	item->next = pevent->printklist;
	item->addr = addr;

	item->printk = strdup(fmt);
	if (!item->printk)
		goto out_free;

	pevent->printklist = item;
	pevent->printk_count++;

	return 0;

out_free:
	free(item);
	errno = ENOMEM;
	return -1;
}

/**
 * pevent_print_printk - print out the stored strings
 * @pevent: handle for the pevent
 *
 * This prints the string formats that were stored.
 */
void pevent_print_printk(struct pevent *pevent)
{
	int i;

	if (!pevent->printk_map)
		printk_map_init(pevent);

	for (i = 0; i < (int)pevent->printk_count; i++) {
		printf("%016llx %s\n",
		       pevent->printk_map[i].addr,
		       pevent->printk_map[i].printk);
	}
}

static struct event_format *alloc_event(void)
{
	return calloc(1, sizeof(struct event_format));
}

static int add_event(struct pevent *pevent, struct event_format *event)
{
	int i;
	struct event_format **events = realloc(pevent->events, sizeof(event) *
					       (pevent->nr_events + 1));
	if (!events)
		return -1;

	pevent->events = events;

	for (i = 0; i < pevent->nr_events; i++) {
		if (pevent->events[i]->id > event->id)
			break;
	}
	if (i < pevent->nr_events)
		memmove(&pevent->events[i + 1],
			&pevent->events[i],
			sizeof(event) * (pevent->nr_events - i));

	pevent->events[i] = event;
	pevent->nr_events++;

	event->pevent = pevent;

	return 0;
}

static int event_item_type(enum event_type type)
{
	switch (type) {
	case EVENT_ITEM ... EVENT_SQUOTE:
		return 1;
	case EVENT_ERROR ... EVENT_DELIM:
	default:
		return 0;
	}
}

static void free_flag_sym(struct print_flag_sym *fsym)
{
	struct print_flag_sym *next;

	while (fsym) {
		next = fsym->next;
		free(fsym->value);
		free(fsym->str);
		free(fsym);
		fsym = next;
	}
}

static void free_arg(struct print_arg *arg)
{
	struct print_arg *farg;

	if (!arg)
		return;

	switch (arg->type) {
	case PRINT_ATOM:
		free(arg->atom.atom);
		break;
	case PRINT_FIELD:
		free(arg->field.name);
		break;
	case PRINT_FLAGS:
		free_arg(arg->flags.field);
		free(arg->flags.delim);
		free_flag_sym(arg->flags.flags);
		break;
	case PRINT_SYMBOL:
		free_arg(arg->symbol.field);
		free_flag_sym(arg->symbol.symbols);
		break;
	case PRINT_HEX:
		free_arg(arg->hex.field);
		free_arg(arg->hex.size);
		break;
	case PRINT_TYPE:
		free(arg->typecast.type);
		free_arg(arg->typecast.item);
		break;
	case PRINT_STRING:
	case PRINT_BSTRING:
		free(arg->string.string);
		break;
	case PRINT_DYNAMIC_ARRAY:
		free(arg->dynarray.index);
		break;
	case PRINT_OP:
		free(arg->op.op);
		free_arg(arg->op.left);
		free_arg(arg->op.right);
		break;
	case PRINT_FUNC:
		while (arg->func.args) {
			farg = arg->func.args;
			arg->func.args = farg->next;
			free_arg(farg);
		}
		break;

	case PRINT_NULL:
	default:
		break;
	}

	free(arg);
}

static enum event_type get_type(int ch)
{
	if (ch == '\n')
		return EVENT_NEWLINE;
	if (isspace(ch))
		return EVENT_SPACE;
	if (isalnum(ch) || ch == '_')
		return EVENT_ITEM;
	if (ch == '\'')
		return EVENT_SQUOTE;
	if (ch == '"')
		return EVENT_DQUOTE;
	if (!isprint(ch))
		return EVENT_NONE;
	if (ch == '(' || ch == ')' || ch == ',')
		return EVENT_DELIM;

	return EVENT_OP;
}

static int __read_char(void)
{
	if (input_buf_ptr >= input_buf_siz)
		return -1;

	return input_buf[input_buf_ptr++];
}

static int __peek_char(void)
{
	if (input_buf_ptr >= input_buf_siz)
		return -1;

	return input_buf[input_buf_ptr];
}

/**
 * pevent_peek_char - peek at the next character that will be read
 *
 * Returns the next character read, or -1 if end of buffer.
 */
int pevent_peek_char(void)
{
	return __peek_char();
}

static int extend_token(char **tok, char *buf, int size)
{
	char *newtok = realloc(*tok, size);

	if (!newtok) {
		free(*tok);
		*tok = NULL;
		return -1;
	}

	if (!*tok)
		strcpy(newtok, buf);
	else
		strcat(newtok, buf);
	*tok = newtok;

	return 0;
}

static enum event_type force_token(const char *str, char **tok);

static enum event_type __read_token(char **tok)
{
	char buf[BUFSIZ];
	int ch, last_ch, quote_ch, next_ch;
	int i = 0;
	int tok_size = 0;
	enum event_type type;

	*tok = NULL;


	ch = __read_char();
	if (ch < 0)
		return EVENT_NONE;

	type = get_type(ch);
	if (type == EVENT_NONE)
		return type;

	buf[i++] = ch;

	switch (type) {
	case EVENT_NEWLINE:
	case EVENT_DELIM:
		if (asprintf(tok, "%c", ch) < 0)
			return EVENT_ERROR;

		return type;

	case EVENT_OP:
		switch (ch) {
		case '-':
			next_ch = __peek_char();
			if (next_ch == '>') {
				buf[i++] = __read_char();
				break;
			}
			/* fall through */
		case '+':
		case '|':
		case '&':
		case '>':
		case '<':
			last_ch = ch;
			ch = __peek_char();
			if (ch != last_ch)
				goto test_equal;
			buf[i++] = __read_char();
			switch (last_ch) {
			case '>':
			case '<':
				goto test_equal;
			default:
				break;
			}
			break;
		case '!':
		case '=':
			goto test_equal;
		default: /* what should we do instead? */
			break;
		}
		buf[i] = 0;
		*tok = strdup(buf);
		return type;

 test_equal:
		ch = __peek_char();
		if (ch == '=')
			buf[i++] = __read_char();
		goto out;

	case EVENT_DQUOTE:
	case EVENT_SQUOTE:
		/* don't keep quotes */
		i--;
		quote_ch = ch;
		last_ch = 0;
 concat:
		do {
			if (i == (BUFSIZ - 1)) {
				buf[i] = 0;
				tok_size += BUFSIZ;

				if (extend_token(tok, buf, tok_size) < 0)
					return EVENT_NONE;
				i = 0;
			}
			last_ch = ch;
			ch = __read_char();
			buf[i++] = ch;
			/* the '\' '\' will cancel itself */
			if (ch == '\\' && last_ch == '\\')
				last_ch = 0;
		} while (ch != quote_ch || last_ch == '\\');
		/* remove the last quote */
		i--;

		/*
		 * For strings (double quotes) check the next token.
		 * If it is another string, concatinate the two.
		 */
		if (type == EVENT_DQUOTE) {
			unsigned long long save_input_buf_ptr = input_buf_ptr;

			do {
				ch = __read_char();
			} while (isspace(ch));
			if (ch == '"')
				goto concat;
			input_buf_ptr = save_input_buf_ptr;
		}

		goto out;

	case EVENT_ERROR ... EVENT_SPACE:
	case EVENT_ITEM:
	default:
		break;
	}

	while (get_type(__peek_char()) == type) {
		if (i == (BUFSIZ - 1)) {
			buf[i] = 0;
			tok_size += BUFSIZ;

			if (extend_token(tok, buf, tok_size) < 0)
				return EVENT_NONE;
			i = 0;
		}
		ch = __read_char();
		buf[i++] = ch;
	}

 out:
	buf[i] = 0;
	if (extend_token(tok, buf, tok_size + i + 1) < 0)
		return EVENT_NONE;

	if (type == EVENT_ITEM) {
		/*
		 * Older versions of the kernel has a bug that
		 * creates invalid symbols and will break the mac80211
		 * parsing. This is a work around to that bug.
		 *
		 * See Linux kernel commit:
		 *  811cb50baf63461ce0bdb234927046131fc7fa8b
		 */
		if (strcmp(*tok, "LOCAL_PR_FMT") == 0) {
			free(*tok);
			*tok = NULL;
			return force_token("\"\%s\" ", tok);
		} else if (strcmp(*tok, "STA_PR_FMT") == 0) {
			free(*tok);
			*tok = NULL;
			return force_token("\" sta:%pM\" ", tok);
		} else if (strcmp(*tok, "VIF_PR_FMT") == 0) {
			free(*tok);
			*tok = NULL;
			return force_token("\" vif:%p(%d)\" ", tok);
		}
	}

	return type;
}

static enum event_type force_token(const char *str, char **tok)
{
	const char *save_input_buf;
	unsigned long long save_input_buf_ptr;
	unsigned long long save_input_buf_siz;
	enum event_type type;
	
	/* save off the current input pointers */
	save_input_buf = input_buf;
	save_input_buf_ptr = input_buf_ptr;
	save_input_buf_siz = input_buf_siz;

	init_input_buf(str, strlen(str));

	type = __read_token(tok);

	/* reset back to original token */
	input_buf = save_input_buf;
	input_buf_ptr = save_input_buf_ptr;
	input_buf_siz = save_input_buf_siz;

	return type;
}

static void free_token(char *tok)
{
	if (tok)
		free(tok);
}

static enum event_type read_token(char **tok)
{
	enum event_type type;

	for (;;) {
		type = __read_token(tok);
		if (type != EVENT_SPACE)
			return type;

		free_token(*tok);
	}

	/* not reached */
	*tok = NULL;
	return EVENT_NONE;
}

/**
 * pevent_read_token - access to utilites to use the pevent parser
 * @tok: The token to return
 *
 * This will parse tokens from the string given by
 * pevent_init_data().
 *
 * Returns the token type.
 */
enum event_type pevent_read_token(char **tok)
{
	return read_token(tok);
}

/**
 * pevent_free_token - free a token returned by pevent_read_token
 * @token: the token to free
 */
void pevent_free_token(char *token)
{
	free_token(token);
}

/* no newline */
static enum event_type read_token_item(char **tok)
{
	enum event_type type;

	for (;;) {
		type = __read_token(tok);
		if (type != EVENT_SPACE && type != EVENT_NEWLINE)
			return type;
		free_token(*tok);
		*tok = NULL;
	}

	/* not reached */
	*tok = NULL;
	return EVENT_NONE;
}

static int test_type(enum event_type type, enum event_type expect)
{
	if (type != expect) {
		do_warning("Error: expected type %d but read %d",
		    expect, type);
		return -1;
	}
	return 0;
}

static int test_type_token(enum event_type type, const char *token,
		    enum event_type expect, const char *expect_tok)
{
	if (type != expect) {
		do_warning("Error: expected type %d but read %d",
		    expect, type);
		return -1;
	}

	if (strcmp(token, expect_tok) != 0) {
		do_warning("Error: expected '%s' but read '%s'",
		    expect_tok, token);
		return -1;
	}
	return 0;
}

static int __read_expect_type(enum event_type expect, char **tok, int newline_ok)
{
	enum event_type type;

	if (newline_ok)
		type = read_token(tok);
	else
		type = read_token_item(tok);
	return test_type(type, expect);
}

static int read_expect_type(enum event_type expect, char **tok)
{
	return __read_expect_type(expect, tok, 1);
}

static int __read_expected(enum event_type expect, const char *str,
			   int newline_ok)
{
	enum event_type type;
	char *token;
	int ret;

	if (newline_ok)
		type = read_token(&token);
	else
		type = read_token_item(&token);

	ret = test_type_token(type, token, expect, str);

	free_token(token);

	return ret;
}

static int read_expected(enum event_type expect, const char *str)
{
	return __read_expected(expect, str, 1);
}

static int read_expected_item(enum event_type expect, const char *str)
{
	return __read_expected(expect, str, 0);
}

static char *event_read_name(void)
{
	char *token;

	if (read_expected(EVENT_ITEM, "name") < 0)
		return NULL;

	if (read_expected(EVENT_OP, ":") < 0)
		return NULL;

	if (read_expect_type(EVENT_ITEM, &token) < 0)
		goto fail;

	return token;

 fail:
	free_token(token);
	return NULL;
}

static int event_read_id(void)
{
	char *token;
	int id;

	if (read_expected_item(EVENT_ITEM, "ID") < 0)
		return -1;

	if (read_expected(EVENT_OP, ":") < 0)
		return -1;

	if (read_expect_type(EVENT_ITEM, &token) < 0)
		goto fail;

	id = strtoul(token, NULL, 0);
	free_token(token);
	return id;

 fail:
	free_token(token);
	return -1;
}

static int field_is_string(struct format_field *field)
{
	if ((field->flags & FIELD_IS_ARRAY) &&
	    (strstr(field->type, "char") || strstr(field->type, "u8") ||
	     strstr(field->type, "s8")))
		return 1;

	return 0;
}

static int field_is_dynamic(struct format_field *field)
{
	if (strncmp(field->type, "__data_loc", 10) == 0)
		return 1;

	return 0;
}

static int field_is_long(struct format_field *field)
{
	/* includes long long */
	if (strstr(field->type, "long"))
		return 1;

	return 0;
}

static unsigned int type_size(const char *name)
{
	/* This covers all FIELD_IS_STRING types. */
	static struct {
		const char *type;
		unsigned int size;
	} table[] = {
		{ "u8",   1 },
		{ "u16",  2 },
		{ "u32",  4 },
		{ "u64",  8 },
		{ "s8",   1 },
		{ "s16",  2 },
		{ "s32",  4 },
		{ "s64",  8 },
		{ "char", 1 },
		{ },
	};
	int i;

	for (i = 0; table[i].type; i++) {
		if (!strcmp(table[i].type, name))
			return table[i].size;
	}

	return 0;
}

static int event_read_fields(struct event_format *event, struct format_field **fields)
{
	struct format_field *field = NULL;
	enum event_type type;
	char *token;
	char *last_token;
	int count = 0;

	do {
		unsigned int size_dynamic = 0;

		type = read_token(&token);
		if (type == EVENT_NEWLINE) {
			free_token(token);
			return count;
		}

		count++;

		if (test_type_token(type, token, EVENT_ITEM, "field"))
			goto fail;
		free_token(token);

		type = read_token(&token);
		/*
		 * The ftrace fields may still use the "special" name.
		 * Just ignore it.
		 */
		if (event->flags & EVENT_FL_ISFTRACE &&
		    type == EVENT_ITEM && strcmp(token, "special") == 0) {
			free_token(token);
			type = read_token(&token);
		}

		if (test_type_token(type, token, EVENT_OP, ":") < 0)
			goto fail;

		free_token(token);
		if (read_expect_type(EVENT_ITEM, &token) < 0)
			goto fail;

		last_token = token;

		field = calloc(1, sizeof(*field));
		if (!field)
			goto fail;

		field->event = event;

		/* read the rest of the type */
		for (;;) {
			type = read_token(&token);
			if (type == EVENT_ITEM ||
			    (type == EVENT_OP && strcmp(token, "*") == 0) ||
			    /*
			     * Some of the ftrace fields are broken and have
			     * an illegal "." in them.
			     */
			    (event->flags & EVENT_FL_ISFTRACE &&
			     type == EVENT_OP && strcmp(token, ".") == 0)) {

				if (strcmp(token, "*") == 0)
					field->flags |= FIELD_IS_POINTER;

				if (field->type) {
					char *new_type;
					new_type = realloc(field->type,
							   strlen(field->type) +
							   strlen(last_token) + 2);
					if (!new_type) {
						free(last_token);
						goto fail;
					}
					field->type = new_type;
					strcat(field->type, " ");
					strcat(field->type, last_token);
					free(last_token);
				} else
					field->type = last_token;
				last_token = token;
				continue;
			}

			break;
		}

		if (!field->type) {
			do_warning("%s: no type found", __func__);
			goto fail;
		}
		field->name = last_token;

		if (test_type(type, EVENT_OP))
			goto fail;

		if (strcmp(token, "[") == 0) {
			enum event_type last_type = type;
			char *brackets = token;
			char *new_brackets;
			int len;

			field->flags |= FIELD_IS_ARRAY;

			type = read_token(&token);

			if (type == EVENT_ITEM)
				field->arraylen = strtoul(token, NULL, 0);
			else
				field->arraylen = 0;

		        while (strcmp(token, "]") != 0) {
				if (last_type == EVENT_ITEM &&
				    type == EVENT_ITEM)
					len = 2;
				else
					len = 1;
				last_type = type;

				new_brackets = realloc(brackets,
						       strlen(brackets) +
						       strlen(token) + len);
				if (!new_brackets) {
					free(brackets);
					goto fail;
				}
				brackets = new_brackets;
				if (len == 2)
					strcat(brackets, " ");
				strcat(brackets, token);
				/* We only care about the last token */
				field->arraylen = strtoul(token, NULL, 0);
				free_token(token);
				type = read_token(&token);
				if (type == EVENT_NONE) {
					do_warning("failed to find token");
					goto fail;
				}
			}

			free_token(token);

			new_brackets = realloc(brackets, strlen(brackets) + 2);
			if (!new_brackets) {
				free(brackets);
				goto fail;
			}
			brackets = new_brackets;
			strcat(brackets, "]");

			/* add brackets to type */

			type = read_token(&token);
			/*
			 * If the next token is not an OP, then it is of
			 * the format: type [] item;
			 */
			if (type == EVENT_ITEM) {
				char *new_type;
				new_type = realloc(field->type,
						   strlen(field->type) +
						   strlen(field->name) +
						   strlen(brackets) + 2);
				if (!new_type) {
					free(brackets);
					goto fail;
				}
				field->type = new_type;
				strcat(field->type, " ");
				strcat(field->type, field->name);
				size_dynamic = type_size(field->name);
				free_token(field->name);
				strcat(field->type, brackets);
				field->name = token;
				type = read_token(&token);
			} else {
				char *new_type;
				new_type = realloc(field->type,
						   strlen(field->type) +
						   strlen(brackets) + 1);
				if (!new_type) {
					free(brackets);
					goto fail;
				}
				field->type = new_type;
				strcat(field->type, brackets);
			}
			free(brackets);
		}

		if (field_is_string(field))
			field->flags |= FIELD_IS_STRING;
		if (field_is_dynamic(field))
			field->flags |= FIELD_IS_DYNAMIC;
		if (field_is_long(field))
			field->flags |= FIELD_IS_LONG;

		if (test_type_token(type, token,  EVENT_OP, ";"))
			goto fail;
		free_token(token);

		if (read_expected(EVENT_ITEM, "offset") < 0)
			goto fail_expect;

		if (read_expected(EVENT_OP, ":") < 0)
			goto fail_expect;

		if (read_expect_type(EVENT_ITEM, &token))
			goto fail;
		field->offset = strtoul(token, NULL, 0);
		free_token(token);

		if (read_expected(EVENT_OP, ";") < 0)
			goto fail_expect;

		if (read_expected(EVENT_ITEM, "size") < 0)
			goto fail_expect;

		if (read_expected(EVENT_OP, ":") < 0)
			goto fail_expect;

		if (read_expect_type(EVENT_ITEM, &token))
			goto fail;
		field->size = strtoul(token, NULL, 0);
		free_token(token);

		if (read_expected(EVENT_OP, ";") < 0)
			goto fail_expect;

		type = read_token(&token);
		if (type != EVENT_NEWLINE) {
			/* newer versions of the kernel have a "signed" type */
			if (test_type_token(type, token, EVENT_ITEM, "signed"))
				goto fail;

			free_token(token);

			if (read_expected(EVENT_OP, ":") < 0)
				goto fail_expect;

			if (read_expect_type(EVENT_ITEM, &token))
				goto fail;

			if (strtoul(token, NULL, 0))
				field->flags |= FIELD_IS_SIGNED;

			free_token(token);
			if (read_expected(EVENT_OP, ";") < 0)
				goto fail_expect;

			if (read_expect_type(EVENT_NEWLINE, &token))
				goto fail;
		}

		free_token(token);

		if (field->flags & FIELD_IS_ARRAY) {
			if (field->arraylen)
				field->elementsize = field->size / field->arraylen;
			else if (field->flags & FIELD_IS_DYNAMIC)
				field->elementsize = size_dynamic;
			else if (field->flags & FIELD_IS_STRING)
				field->elementsize = 1;
			else if (field->flags & FIELD_IS_LONG)
				field->elementsize = event->pevent ?
						     event->pevent->long_size :
						     sizeof(long);
		} else
			field->elementsize = field->size;

		*fields = field;
		fields = &field->next;

	} while (1);

	return 0;

fail:
	free_token(token);
fail_expect:
	if (field) {
		free(field->type);
		free(field->name);
		free(field);
	}
	return -1;
}

static int event_read_format(struct event_format *event)
{
	char *token;
	int ret;

	if (read_expected_item(EVENT_ITEM, "format") < 0)
		return -1;

	if (read_expected(EVENT_OP, ":") < 0)
		return -1;

	if (read_expect_type(EVENT_NEWLINE, &token))
		goto fail;
	free_token(token);

	ret = event_read_fields(event, &event->format.common_fields);
	if (ret < 0)
		return ret;
	event->format.nr_common = ret;

	ret = event_read_fields(event, &event->format.fields);
	if (ret < 0)
		return ret;
	event->format.nr_fields = ret;

	return 0;

 fail:
	free_token(token);
	return -1;
}

static enum event_type
process_arg_token(struct event_format *event, struct print_arg *arg,
		  char **tok, enum event_type type);

static enum event_type
process_arg(struct event_format *event, struct print_arg *arg, char **tok)
{
	enum event_type type;
	char *token;

	type = read_token(&token);
	*tok = token;

	return process_arg_token(event, arg, tok, type);
}

static enum event_type
process_op(struct event_format *event, struct print_arg *arg, char **tok);

static enum event_type
process_cond(struct event_format *event, struct print_arg *top, char **tok)
{
	struct print_arg *arg, *left, *right;
	enum event_type type;
	char *token = NULL;

	arg = alloc_arg();
	left = alloc_arg();
	right = alloc_arg();

	if (!arg || !left || !right) {
		do_warning("%s: not enough memory!", __func__);
		/* arg will be freed at out_free */
		free_arg(left);
		free_arg(right);
		goto out_free;
	}

	arg->type = PRINT_OP;
	arg->op.left = left;
	arg->op.right = right;

	*tok = NULL;
	type = process_arg(event, left, &token);

 again:
	/* Handle other operations in the arguments */
	if (type == EVENT_OP && strcmp(token, ":") != 0) {
		type = process_op(event, left, &token);
		goto again;
	}

	if (test_type_token(type, token, EVENT_OP, ":"))
		goto out_free;

	arg->op.op = token;

	type = process_arg(event, right, &token);

	top->op.right = arg;

	*tok = token;
	return type;

out_free:
	/* Top may point to itself */
	top->op.right = NULL;
	free_token(token);
	free_arg(arg);
	return EVENT_ERROR;
}

static enum event_type
process_array(struct event_format *event, struct print_arg *top, char **tok)
{
	struct print_arg *arg;
	enum event_type type;
	char *token = NULL;

	arg = alloc_arg();
	if (!arg) {
		do_warning("%s: not enough memory!", __func__);
		/* '*tok' is set to top->op.op.  No need to free. */
		*tok = NULL;
		return EVENT_ERROR;
	}

	*tok = NULL;
	type = process_arg(event, arg, &token);
	if (test_type_token(type, token, EVENT_OP, "]"))
		goto out_free;

	top->op.right = arg;

	free_token(token);
	type = read_token_item(&token);
	*tok = token;

	return type;

out_free:
	free_token(token);
	free_arg(arg);
	return EVENT_ERROR;
}

static int get_op_prio(char *op)
{
	if (!op[1]) {
		switch (op[0]) {
		case '~':
		case '!':
			return 4;
		case '*':
		case '/':
		case '%':
			return 6;
		case '+':
		case '-':
			return 7;
			/* '>>' and '<<' are 8 */
		case '<':
		case '>':
			return 9;
			/* '==' and '!=' are 10 */
		case '&':
			return 11;
		case '^':
			return 12;
		case '|':
			return 13;
		case '?':
			return 16;
		default:
			do_warning("unknown op '%c'", op[0]);
			return -1;
		}
	} else {
		if (strcmp(op, "++") == 0 ||
		    strcmp(op, "--") == 0) {
			return 3;
		} else if (strcmp(op, ">>") == 0 ||
			   strcmp(op, "<<") == 0) {
			return 8;
		} else if (strcmp(op, ">=") == 0 ||
			   strcmp(op, "<=") == 0) {
			return 9;
		} else if (strcmp(op, "==") == 0 ||
			   strcmp(op, "!=") == 0) {
			return 10;
		} else if (strcmp(op, "&&") == 0) {
			return 14;
		} else if (strcmp(op, "||") == 0) {
			return 15;
		} else {
			do_warning("unknown op '%s'", op);
			return -1;
		}
	}
}

static int set_op_prio(struct print_arg *arg)
{

	/* single ops are the greatest */
	if (!arg->op.left || arg->op.left->type == PRINT_NULL)
		arg->op.prio = 0;
	else
		arg->op.prio = get_op_prio(arg->op.op);

	return arg->op.prio;
}

/* Note, *tok does not get freed, but will most likely be saved */
static enum event_type
process_op(struct event_format *event, struct print_arg *arg, char **tok)
{
	struct print_arg *left, *right = NULL;
	enum event_type type;
	char *token;

	/* the op is passed in via tok */
	token = *tok;

	if (arg->type == PRINT_OP && !arg->op.left) {
		/* handle single op */
		if (token[1]) {
			do_warning("bad op token %s", token);
			goto out_free;
		}
		switch (token[0]) {
		case '~':
		case '!':
		case '+':
		case '-':
			break;
		default:
			do_warning("bad op token %s", token);
			goto out_free;

		}

		/* make an empty left */
		left = alloc_arg();
		if (!left)
			goto out_warn_free;

		left->type = PRINT_NULL;
		arg->op.left = left;

		right = alloc_arg();
		if (!right)
			goto out_warn_free;

		arg->op.right = right;

		/* do not free the token, it belongs to an op */
		*tok = NULL;
		type = process_arg(event, right, tok);

	} else if (strcmp(token, "?") == 0) {

		left = alloc_arg();
		if (!left)
			goto out_warn_free;

		/* copy the top arg to the left */
		*left = *arg;

		arg->type = PRINT_OP;
		arg->op.op = token;
		arg->op.left = left;
		arg->op.prio = 0;

		/* it will set arg->op.right */
		type = process_cond(event, arg, tok);

	} else if (strcmp(token, ">>") == 0 ||
		   strcmp(token, "<<") == 0 ||
		   strcmp(token, "&") == 0 ||
		   strcmp(token, "|") == 0 ||
		   strcmp(token, "&&") == 0 ||
		   strcmp(token, "||") == 0 ||
		   strcmp(token, "-") == 0 ||
		   strcmp(token, "+") == 0 ||
		   strcmp(token, "*") == 0 ||
		   strcmp(token, "^") == 0 ||
		   strcmp(token, "/") == 0 ||
		   strcmp(token, "<") == 0 ||
		   strcmp(token, ">") == 0 ||
		   strcmp(token, "<=") == 0 ||
		   strcmp(token, ">=") == 0 ||
		   strcmp(token, "==") == 0 ||
		   strcmp(token, "!=") == 0) {

		left = alloc_arg();
		if (!left)
			goto out_warn_free;

		/* copy the top arg to the left */
		*left = *arg;

		arg->type = PRINT_OP;
		arg->op.op = token;
		arg->op.left = left;
		arg->op.right = NULL;

		if (set_op_prio(arg) == -1) {
			event->flags |= EVENT_FL_FAILED;
			/* arg->op.op (= token) will be freed at out_free */
			arg->op.op = NULL;
			goto out_free;
		}

		type = read_token_item(&token);
		*tok = token;

		/* could just be a type pointer */
		if ((strcmp(arg->op.op, "*") == 0) &&
		    type == EVENT_DELIM && (strcmp(token, ")") == 0)) {
			char *new_atom;

			if (left->type != PRINT_ATOM) {
				do_warning("bad pointer type");
				goto out_free;
			}
			new_atom = realloc(left->atom.atom,
					    strlen(left->atom.atom) + 3);
			if (!new_atom)
				goto out_warn_free;

			left->atom.atom = new_atom;
			strcat(left->atom.atom, " *");
			free(arg->op.op);
			*arg = *left;
			free(left);

			return type;
		}

		right = alloc_arg();
		if (!right)
			goto out_warn_free;

		type = process_arg_token(event, right, tok, type);
		arg->op.right = right;

	} else if (strcmp(token, "[") == 0) {

		left = alloc_arg();
		if (!left)
			goto out_warn_free;

		*left = *arg;

		arg->type = PRINT_OP;
		arg->op.op = token;
		arg->op.left = left;

		arg->op.prio = 0;

		/* it will set arg->op.right */
		type = process_array(event, arg, tok);

	} else {
		do_warning("unknown op '%s'", token);
		event->flags |= EVENT_FL_FAILED;
		/* the arg is now the left side */
		goto out_free;
	}

	if (type == EVENT_OP && strcmp(*tok, ":") != 0) {
		int prio;

		/* higher prios need to be closer to the root */
		prio = get_op_prio(*tok);

		if (prio > arg->op.prio)
			return process_op(event, arg, tok);

		return process_op(event, right, tok);
	}

	return type;

out_warn_free:
	do_warning("%s: not enough memory!", __func__);
out_free:
	free_token(token);
	*tok = NULL;
	return EVENT_ERROR;
}

static enum event_type
process_entry(struct event_format *event __maybe_unused, struct print_arg *arg,
	      char **tok)
{
	enum event_type type;
	char *field;
	char *token;

	if (read_expected(EVENT_OP, "->") < 0)
		goto out_err;

	if (read_expect_type(EVENT_ITEM, &token) < 0)
		goto out_free;
	field = token;

	arg->type = PRINT_FIELD;
	arg->field.name = field;

	if (is_flag_field) {
		arg->field.field = pevent_find_any_field(event, arg->field.name);
		arg->field.field->flags |= FIELD_IS_FLAG;
		is_flag_field = 0;
	} else if (is_symbolic_field) {
		arg->field.field = pevent_find_any_field(event, arg->field.name);
		arg->field.field->flags |= FIELD_IS_SYMBOLIC;
		is_symbolic_field = 0;
	}

	type = read_token(&token);
	*tok = token;

	return type;

 out_free:
	free_token(token);
 out_err:
	*tok = NULL;
	return EVENT_ERROR;
}

static char *arg_eval (struct print_arg *arg);

static unsigned long long
eval_type_str(unsigned long long val, const char *type, int pointer)
{
	int sign = 0;
	char *ref;
	int len;

	len = strlen(type);

	if (pointer) {

		if (type[len-1] != '*') {
			do_warning("pointer expected with non pointer type");
			return val;
		}

		ref = malloc(len);
		if (!ref) {
			do_warning("%s: not enough memory!", __func__);
			return val;
		}
		memcpy(ref, type, len);

		/* chop off the " *" */
		ref[len - 2] = 0;

		val = eval_type_str(val, ref, 0);
		free(ref);
		return val;
	}

	/* check if this is a pointer */
	if (type[len - 1] == '*')
		return val;

	/* Try to figure out the arg size*/
	if (strncmp(type, "struct", 6) == 0)
		/* all bets off */
		return val;

	if (strcmp(type, "u8") == 0)
		return val & 0xff;

	if (strcmp(type, "u16") == 0)
		return val & 0xffff;

	if (strcmp(type, "u32") == 0)
		return val & 0xffffffff;

	if (strcmp(type, "u64") == 0 ||
	    strcmp(type, "s64"))
		return val;

	if (strcmp(type, "s8") == 0)
		return (unsigned long long)(char)val & 0xff;

	if (strcmp(type, "s16") == 0)
		return (unsigned long long)(short)val & 0xffff;

	if (strcmp(type, "s32") == 0)
		return (unsigned long long)(int)val & 0xffffffff;

	if (strncmp(type, "unsigned ", 9) == 0) {
		sign = 0;
		type += 9;
	}

	if (strcmp(type, "char") == 0) {
		if (sign)
			return (unsigned long long)(char)val & 0xff;
		else
			return val & 0xff;
	}

	if (strcmp(type, "short") == 0) {
		if (sign)
			return (unsigned long long)(short)val & 0xffff;
		else
			return val & 0xffff;
	}

	if (strcmp(type, "int") == 0) {
		if (sign)
			return (unsigned long long)(int)val & 0xffffffff;
		else
			return val & 0xffffffff;
	}

	return val;
}

/*
 * Try to figure out the type.
 */
static unsigned long long
eval_type(unsigned long long val, struct print_arg *arg, int pointer)
{
	if (arg->type != PRINT_TYPE) {
		do_warning("expected type argument");
		return 0;
	}

	return eval_type_str(val, arg->typecast.type, pointer);
}

static int arg_num_eval(struct print_arg *arg, long long *val)
{
	long long left, right;
	int ret = 1;

	switch (arg->type) {
	case PRINT_ATOM:
		*val = strtoll(arg->atom.atom, NULL, 0);
		break;
	case PRINT_TYPE:
		ret = arg_num_eval(arg->typecast.item, val);
		if (!ret)
			break;
		*val = eval_type(*val, arg, 0);
		break;
	case PRINT_OP:
		switch (arg->op.op[0]) {
		case '|':
			ret = arg_num_eval(arg->op.left, &left);
			if (!ret)
				break;
			ret = arg_num_eval(arg->op.right, &right);
			if (!ret)
				break;
			if (arg->op.op[1])
				*val = left || right;
			else
				*val = left | right;
			break;
		case '&':
			ret = arg_num_eval(arg->op.left, &left);
			if (!ret)
				break;
			ret = arg_num_eval(arg->op.right, &right);
			if (!ret)
				break;
			if (arg->op.op[1])
				*val = left && right;
			else
				*val = left & right;
			break;
		case '<':
			ret = arg_num_eval(arg->op.left, &left);
			if (!ret)
				break;
			ret = arg_num_eval(arg->op.right, &right);
			if (!ret)
				break;
			switch (arg->op.op[1]) {
			case 0:
				*val = left < right;
				break;
			case '<':
				*val = left << right;
				break;
			case '=':
				*val = left <= right;
				break;
			default:
				do_warning("unknown op '%s'", arg->op.op);
				ret = 0;
			}
			break;
		case '>':
			ret = arg_num_eval(arg->op.left, &left);
			if (!ret)
				break;
			ret = arg_num_eval(arg->op.right, &right);
			if (!ret)
				break;
			switch (arg->op.op[1]) {
			case 0:
				*val = left > right;
				break;
			case '>':
				*val = left >> right;
				break;
			case '=':
				*val = left >= right;
				break;
			default:
				do_warning("unknown op '%s'", arg->op.op);
				ret = 0;
			}
			break;
		case '=':
			ret = arg_num_eval(arg->op.left, &left);
			if (!ret)
				break;
			ret = arg_num_eval(arg->op.right, &right);
			if (!ret)
				break;

			if (arg->op.op[1] != '=') {
				do_warning("unknown op '%s'", arg->op.op);
				ret = 0;
			} else
				*val = left == right;
			break;
		case '!':
			ret = arg_num_eval(arg->op.left, &left);
			if (!ret)
				break;
			ret = arg_num_eval(arg->op.right, &right);
			if (!ret)
				break;

			switch (arg->op.op[1]) {
			case '=':
				*val = left != right;
				break;
			default:
				do_warning("unknown op '%s'", arg->op.op);
				ret = 0;
			}
			break;
		case '-':
			/* check for negative */
			if (arg->op.left->type == PRINT_NULL)
				left = 0;
			else
				ret = arg_num_eval(arg->op.left, &left);
			if (!ret)
				break;
			ret = arg_num_eval(arg->op.right, &right);
			if (!ret)
				break;
			*val = left - right;
			break;
		case '+':
			if (arg->op.left->type == PRINT_NULL)
				left = 0;
			else
				ret = arg_num_eval(arg->op.left, &left);
			if (!ret)
				break;
			ret = arg_num_eval(arg->op.right, &right);
			if (!ret)
				break;
			*val = left + right;
			break;
		default:
			do_warning("unknown op '%s'", arg->op.op);
			ret = 0;
		}
		break;

	case PRINT_NULL:
	case PRINT_FIELD ... PRINT_SYMBOL:
	case PRINT_STRING:
	case PRINT_BSTRING:
	default:
		do_warning("invalid eval type %d", arg->type);
		ret = 0;

	}
	return ret;
}

static char *arg_eval (struct print_arg *arg)
{
	long long val;
	static char buf[20];

	switch (arg->type) {
	case PRINT_ATOM:
		return arg->atom.atom;
	case PRINT_TYPE:
		return arg_eval(arg->typecast.item);
	case PRINT_OP:
		if (!arg_num_eval(arg, &val))
			break;
		sprintf(buf, "%lld", val);
		return buf;

	case PRINT_NULL:
	case PRINT_FIELD ... PRINT_SYMBOL:
	case PRINT_STRING:
	case PRINT_BSTRING:
	default:
		do_warning("invalid eval type %d", arg->type);
		break;
	}

	return NULL;
}

static enum event_type
process_fields(struct event_format *event, struct print_flag_sym **list, char **tok)
{
	enum event_type type;
	struct print_arg *arg = NULL;
	struct print_flag_sym *field;
	char *token = *tok;
	char *value;

	do {
		free_token(token);
		type = read_token_item(&token);
		if (test_type_token(type, token, EVENT_OP, "{"))
			break;

		arg = alloc_arg();
		if (!arg)
			goto out_free;

		free_token(token);
		type = process_arg(event, arg, &token);

		if (type == EVENT_OP)
			type = process_op(event, arg, &token);

		if (type == EVENT_ERROR)
			goto out_free;

		if (test_type_token(type, token, EVENT_DELIM, ","))
			goto out_free;

		field = calloc(1, sizeof(*field));
		if (!field)
			goto out_free;

		value = arg_eval(arg);
		if (value == NULL)
			goto out_free_field;
		field->value = strdup(value);
		if (field->value == NULL)
			goto out_free_field;

		free_arg(arg);
		arg = alloc_arg();
		if (!arg)
			goto out_free;

		free_token(token);
		type = process_arg(event, arg, &token);
		if (test_type_token(type, token, EVENT_OP, "}"))
			goto out_free_field;

		value = arg_eval(arg);
		if (value == NULL)
			goto out_free_field;
		field->str = strdup(value);
		if (field->str == NULL)
			goto out_free_field;
		free_arg(arg);
		arg = NULL;

		*list = field;
		list = &field->next;

		free_token(token);
		type = read_token_item(&token);
	} while (type == EVENT_DELIM && strcmp(token, ",") == 0);

	*tok = token;
	return type;

out_free_field:
	free_flag_sym(field);
out_free:
	free_arg(arg);
	free_token(token);
	*tok = NULL;

	return EVENT_ERROR;
}

static enum event_type
process_flags(struct event_format *event, struct print_arg *arg, char **tok)
{
	struct print_arg *field;
	enum event_type type;
	char *token;

	memset(arg, 0, sizeof(*arg));
	arg->type = PRINT_FLAGS;

	field = alloc_arg();
	if (!field) {
		do_warning("%s: not enough memory!", __func__);
		goto out_free;
	}

	type = process_arg(event, field, &token);

	/* Handle operations in the first argument */
	while (type == EVENT_OP)
		type = process_op(event, field, &token);

	if (test_type_token(type, token, EVENT_DELIM, ","))
		goto out_free_field;
	free_token(token);

	arg->flags.field = field;

	type = read_token_item(&token);
	if (event_item_type(type)) {
		arg->flags.delim = token;
		type = read_token_item(&token);
	}

	if (test_type_token(type, token, EVENT_DELIM, ","))
		goto out_free;

	type = process_fields(event, &arg->flags.flags, &token);
	if (test_type_token(type, token, EVENT_DELIM, ")"))
		goto out_free;

	free_token(token);
	type = read_token_item(tok);
	return type;

out_free_field:
	free_arg(field);
out_free:
	free_token(token);
	*tok = NULL;
	return EVENT_ERROR;
}

static enum event_type
process_symbols(struct event_format *event, struct print_arg *arg, char **tok)
{
	struct print_arg *field;
	enum event_type type;
	char *token;

	memset(arg, 0, sizeof(*arg));
	arg->type = PRINT_SYMBOL;

	field = alloc_arg();
	if (!field) {
		do_warning("%s: not enough memory!", __func__);
		goto out_free;
	}

	type = process_arg(event, field, &token);
	if (test_type_token(type, token, EVENT_DELIM, ","))
		goto out_free_field;

	arg->symbol.field = field;

	type = process_fields(event, &arg->symbol.symbols, &token);
	if (test_type_token(type, token, EVENT_DELIM, ")"))
		goto out_free;

	free_token(token);
	type = read_token_item(tok);
	return type;

out_free_field:
	free_arg(field);
out_free:
	free_token(token);
	*tok = NULL;
	return EVENT_ERROR;
}

static enum event_type
process_hex(struct event_format *event, struct print_arg *arg, char **tok)
{
	struct print_arg *field;
	enum event_type type;
	char *token;

	memset(arg, 0, sizeof(*arg));
	arg->type = PRINT_HEX;

	field = alloc_arg();
	if (!field) {
		do_warning("%s: not enough memory!", __func__);
		goto out_free;
	}

	type = process_arg(event, field, &token);

	if (test_type_token(type, token, EVENT_DELIM, ","))
		goto out_free;

	arg->hex.field = field;

	free_token(token);

	field = alloc_arg();
	if (!field) {
		do_warning("%s: not enough memory!", __func__);
		*tok = NULL;
		return EVENT_ERROR;
	}

	type = process_arg(event, field, &token);

	if (test_type_token(type, token, EVENT_DELIM, ")"))
		goto out_free;

	arg->hex.size = field;

	free_token(token);
	type = read_token_item(tok);
	return type;

 out_free:
	free_arg(field);
	free_token(token);
	*tok = NULL;
	return EVENT_ERROR;
}

static enum event_type
process_dynamic_array(struct event_format *event, struct print_arg *arg, char **tok)
{
	struct format_field *field;
	enum event_type type;
	char *token;

	memset(arg, 0, sizeof(*arg));
	arg->type = PRINT_DYNAMIC_ARRAY;

	/*
	 * The item within the parenthesis is another field that holds
	 * the index into where the array starts.
	 */
	type = read_token(&token);
	*tok = token;
	if (type != EVENT_ITEM)
		goto out_free;

	/* Find the field */

	field = pevent_find_field(event, token);
	if (!field)
		goto out_free;

	arg->dynarray.field = field;
	arg->dynarray.index = 0;

	if (read_expected(EVENT_DELIM, ")") < 0)
		goto out_free;

	free_token(token);
	type = read_token_item(&token);
	*tok = token;
	if (type != EVENT_OP || strcmp(token, "[") != 0)
		return type;

	free_token(token);
	arg = alloc_arg();
	if (!arg) {
		do_warning("%s: not enough memory!", __func__);
		*tok = NULL;
		return EVENT_ERROR;
	}

	type = process_arg(event, arg, &token);
	if (type == EVENT_ERROR)
		goto out_free_arg;

	if (!test_type_token(type, token, EVENT_OP, "]"))
		goto out_free_arg;

	free_token(token);
	type = read_token_item(tok);
	return type;

 out_free_arg:
	free_arg(arg);
 out_free:
	free_token(token);
	*tok = NULL;
	return EVENT_ERROR;
}

static enum event_type
process_paren(struct event_format *event, struct print_arg *arg, char **tok)
{
	struct print_arg *item_arg;
	enum event_type type;
	char *token;

	type = process_arg(event, arg, &token);

	if (type == EVENT_ERROR)
		goto out_free;

	if (type == EVENT_OP)
		type = process_op(event, arg, &token);

	if (type == EVENT_ERROR)
		goto out_free;

	if (test_type_token(type, token, EVENT_DELIM, ")"))
		goto out_free;

	free_token(token);
	type = read_token_item(&token);

	/*
	 * If the next token is an item or another open paren, then
	 * this was a typecast.
	 */
	if (event_item_type(type) ||
	    (type == EVENT_DELIM && strcmp(token, "(") == 0)) {

		/* make this a typecast and contine */

		/* prevous must be an atom */
		if (arg->type != PRINT_ATOM) {
			do_warning("previous needed to be PRINT_ATOM");
			goto out_free;
		}

		item_arg = alloc_arg();
		if (!item_arg) {
			do_warning("%s: not enough memory!", __func__);
			goto out_free;
		}

		arg->type = PRINT_TYPE;
		arg->typecast.type = arg->atom.atom;
		arg->typecast.item = item_arg;
		type = process_arg_token(event, item_arg, &token, type);

	}

	*tok = token;
	return type;

 out_free:
	free_token(token);
	*tok = NULL;
	return EVENT_ERROR;
}


static enum event_type
process_str(struct event_format *event __maybe_unused, struct print_arg *arg,
	    char **tok)
{
	enum event_type type;
	char *token;

	if (read_expect_type(EVENT_ITEM, &token) < 0)
		goto out_free;

	arg->type = PRINT_STRING;
	arg->string.string = token;
	arg->string.offset = -1;

	if (read_expected(EVENT_DELIM, ")") < 0)
		goto out_err;

	type = read_token(&token);
	*tok = token;

	return type;

 out_free:
	free_token(token);
 out_err:
	*tok = NULL;
	return EVENT_ERROR;
}

static struct pevent_function_handler *
find_func_handler(struct pevent *pevent, char *func_name)
{
	struct pevent_function_handler *func;

	if (!pevent)
		return NULL;

	for (func = pevent->func_handlers; func; func = func->next) {
		if (strcmp(func->name, func_name) == 0)
			break;
	}

	return func;
}

static void remove_func_handler(struct pevent *pevent, char *func_name)
{
	struct pevent_function_handler *func;
	struct pevent_function_handler **next;

	next = &pevent->func_handlers;
	while ((func = *next)) {
		if (strcmp(func->name, func_name) == 0) {
			*next = func->next;
			free_func_handle(func);
			break;
		}
		next = &func->next;
	}
}

static enum event_type
process_func_handler(struct event_format *event, struct pevent_function_handler *func,
		     struct print_arg *arg, char **tok)
{
	struct print_arg **next_arg;
	struct print_arg *farg;
	enum event_type type;
	char *token;
	const char *test;
	int i;

	arg->type = PRINT_FUNC;
	arg->func.func = func;

	*tok = NULL;

	next_arg = &(arg->func.args);
	for (i = 0; i < func->nr_args; i++) {
		farg = alloc_arg();
		if (!farg) {
			do_warning("%s: not enough memory!", __func__);
			return EVENT_ERROR;
		}

		type = process_arg(event, farg, &token);
		if (i < (func->nr_args - 1))
			test = ",";
		else
			test = ")";

		if (test_type_token(type, token, EVENT_DELIM, test)) {
			free_arg(farg);
			free_token(token);
			return EVENT_ERROR;
		}

		*next_arg = farg;
		next_arg = &(farg->next);
		free_token(token);
	}

	type = read_token(&token);
	*tok = token;

	return type;
}

static enum event_type
process_function(struct event_format *event, struct print_arg *arg,
		 char *token, char **tok)
{
	struct pevent_function_handler *func;

	if (strcmp(token, "__print_flags") == 0) {
		free_token(token);
		is_flag_field = 1;
		return process_flags(event, arg, tok);
	}
	if (strcmp(token, "__print_symbolic") == 0) {
		free_token(token);
		is_symbolic_field = 1;
		return process_symbols(event, arg, tok);
	}
	if (strcmp(token, "__print_hex") == 0) {
		free_token(token);
		return process_hex(event, arg, tok);
	}
	if (strcmp(token, "__get_str") == 0) {
		free_token(token);
		return process_str(event, arg, tok);
	}
	if (strcmp(token, "__get_dynamic_array") == 0) {
		free_token(token);
		return process_dynamic_array(event, arg, tok);
	}

	func = find_func_handler(event->pevent, token);
	if (func) {
		free_token(token);
		return process_func_handler(event, func, arg, tok);
	}

	do_warning("function %s not defined", token);
	free_token(token);
	return EVENT_ERROR;
}

static enum event_type
process_arg_token(struct event_format *event, struct print_arg *arg,
		  char **tok, enum event_type type)
{
	char *token;
	char *atom;

	token = *tok;

	switch (type) {
	case EVENT_ITEM:
		if (strcmp(token, "REC") == 0) {
			free_token(token);
			type = process_entry(event, arg, &token);
			break;
		}
		atom = token;
		/* test the next token */
		type = read_token_item(&token);

		/*
		 * If the next token is a parenthesis, then this
		 * is a function.
		 */
		if (type == EVENT_DELIM && strcmp(token, "(") == 0) {
			free_token(token);
			token = NULL;
			/* this will free atom. */
			type = process_function(event, arg, atom, &token);
			break;
		}
		/* atoms can be more than one token long */
		while (type == EVENT_ITEM) {
			char *new_atom;
			new_atom = realloc(atom,
					   strlen(atom) + strlen(token) + 2);
			if (!new_atom) {
				free(atom);
				*tok = NULL;
				free_token(token);
				return EVENT_ERROR;
			}
			atom = new_atom;
			strcat(atom, " ");
			strcat(atom, token);
			free_token(token);
			type = read_token_item(&token);
		}

		arg->type = PRINT_ATOM;
		arg->atom.atom = atom;
		break;

	case EVENT_DQUOTE:
	case EVENT_SQUOTE:
		arg->type = PRINT_ATOM;
		arg->atom.atom = token;
		type = read_token_item(&token);
		break;
	case EVENT_DELIM:
		if (strcmp(token, "(") == 0) {
			free_token(token);
			type = process_paren(event, arg, &token);
			break;
		}
	case EVENT_OP:
		/* handle single ops */
		arg->type = PRINT_OP;
		arg->op.op = token;
		arg->op.left = NULL;
		type = process_op(event, arg, &token);

		/* On error, the op is freed */
		if (type == EVENT_ERROR)
			arg->op.op = NULL;

		/* return error type if errored */
		break;

	case EVENT_ERROR ... EVENT_NEWLINE:
	default:
		do_warning("unexpected type %d", type);
		return EVENT_ERROR;
	}
	*tok = token;

	return type;
}

static int event_read_print_args(struct event_format *event, struct print_arg **list)
{
	enum event_type type = EVENT_ERROR;
	struct print_arg *arg;
	char *token;
	int args = 0;

	do {
		if (type == EVENT_NEWLINE) {
			type = read_token_item(&token);
			continue;
		}

		arg = alloc_arg();
		if (!arg) {
			do_warning("%s: not enough memory!", __func__);
			return -1;
		}

		type = process_arg(event, arg, &token);

		if (type == EVENT_ERROR) {
			free_token(token);
			free_arg(arg);
			return -1;
		}

		*list = arg;
		args++;

		if (type == EVENT_OP) {
			type = process_op(event, arg, &token);
			free_token(token);
			if (type == EVENT_ERROR) {
				*list = NULL;
				free_arg(arg);
				return -1;
			}
			list = &arg->next;
			continue;
		}

		if (type == EVENT_DELIM && strcmp(token, ",") == 0) {
			free_token(token);
			*list = arg;
			list = &arg->next;
			continue;
		}
		break;
	} while (type != EVENT_NONE);

	if (type != EVENT_NONE && type != EVENT_ERROR)
		free_token(token);

	return args;
}

static int event_read_print(struct event_format *event)
{
	enum event_type type;
	char *token;
	int ret;

	if (read_expected_item(EVENT_ITEM, "print") < 0)
		return -1;

	if (read_expected(EVENT_ITEM, "fmt") < 0)
		return -1;

	if (read_expected(EVENT_OP, ":") < 0)
		return -1;

	if (read_expect_type(EVENT_DQUOTE, &token) < 0)
		goto fail;

 concat:
	event->print_fmt.format = token;
	event->print_fmt.args = NULL;

	/* ok to have no arg */
	type = read_token_item(&token);

	if (type == EVENT_NONE)
		return 0;

	/* Handle concatenation of print lines */
	if (type == EVENT_DQUOTE) {
		char *cat;

		if (asprintf(&cat, "%s%s", event->print_fmt.format, token) < 0)
			goto fail;
		free_token(token);
		free_token(event->print_fmt.format);
		event->print_fmt.format = NULL;
		token = cat;
		goto concat;
	}
			     
	if (test_type_token(type, token, EVENT_DELIM, ","))
		goto fail;

	free_token(token);

	ret = event_read_print_args(event, &event->print_fmt.args);
	if (ret < 0)
		return -1;

	return ret;

 fail:
	free_token(token);
	return -1;
}

/**
 * pevent_find_common_field - return a common field by event
 * @event: handle for the event
 * @name: the name of the common field to return
 *
 * Returns a common field from the event by the given @name.
 * This only searchs the common fields and not all field.
 */
struct format_field *
pevent_find_common_field(struct event_format *event, const char *name)
{
	struct format_field *format;

	for (format = event->format.common_fields;
	     format; format = format->next) {
		if (strcmp(format->name, name) == 0)
			break;
	}

	return format;
}

/**
 * pevent_find_field - find a non-common field
 * @event: handle for the event
 * @name: the name of the non-common field
 *
 * Returns a non-common field by the given @name.
 * This does not search common fields.
 */
struct format_field *
pevent_find_field(struct event_format *event, const char *name)
{
	struct format_field *format;

	for (format = event->format.fields;
	     format; format = format->next) {
		if (strcmp(format->name, name) == 0)
			break;
	}

	return format;
}

/**
 * pevent_find_any_field - find any field by name
 * @event: handle for the event
 * @name: the name of the field
 *
 * Returns a field by the given @name.
 * This searchs the common field names first, then
 * the non-common ones if a common one was not found.
 */
struct format_field *
pevent_find_any_field(struct event_format *event, const char *name)
{
	struct format_field *format;

	format = pevent_find_common_field(event, name);
	if (format)
		return format;
	return pevent_find_field(event, name);
}

/**
 * pevent_read_number - read a number from data
 * @pevent: handle for the pevent
 * @ptr: the raw data
 * @size: the size of the data that holds the number
 *
 * Returns the number (converted to host) from the
 * raw data.
 */
unsigned long long pevent_read_number(struct pevent *pevent,
				      const void *ptr, int size)
{
	switch (size) {
	case 1:
		return *(unsigned char *)ptr;
	case 2:
		return data2host2(pevent, ptr);
	case 4:
		return data2host4(pevent, ptr);
	case 8:
		return data2host8(pevent, ptr);
	default:
		/* BUG! */
		return 0;
	}
}

/**
 * pevent_read_number_field - read a number from data
 * @field: a handle to the field
 * @data: the raw data to read
 * @value: the value to place the number in
 *
 * Reads raw data according to a field offset and size,
 * and translates it into @value.
 *
 * Returns 0 on success, -1 otherwise.
 */
int pevent_read_number_field(struct format_field *field, const void *data,
			     unsigned long long *value)
{
	if (!field)
		return -1;
	switch (field->size) {
	case 1:
	case 2:
	case 4:
	case 8:
		*value = pevent_read_number(field->event->pevent,
					    data + field->offset, field->size);
		return 0;
	default:
		return -1;
	}
}

static int get_common_info(struct pevent *pevent,
			   const char *type, int *offset, int *size)
{
	struct event_format *event;
	struct format_field *field;

	/*
	 * All events should have the same common elements.
	 * Pick any event to find where the type is;
	 */
	if (!pevent->events) {
		do_warning("no event_list!");
		return -1;
	}

	event = pevent->events[0];
	field = pevent_find_common_field(event, type);
	if (!field)
		return -1;

	*offset = field->offset;
	*size = field->size;

	return 0;
}

static int __parse_common(struct pevent *pevent, void *data,
			  int *size, int *offset, const char *name)
{
	int ret;

	if (!*size) {
		ret = get_common_info(pevent, name, offset, size);
		if (ret < 0)
			return ret;
	}
	return pevent_read_number(pevent, data + *offset, *size);
}

static int trace_parse_common_type(struct pevent *pevent, void *data)
{
	return __parse_common(pevent, data,
			      &pevent->type_size, &pevent->type_offset,
			      "common_type");
}