/*

 * This file is part of ltrace.

 * Copyright (C) 2011, 2012 Petr Machata, Red Hat Inc.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation; either version 2 of the

 * License, or (at your option) any later version.

 *

 * 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

 * General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA

 * 02110-1301 USA

 */

#include <stdlib.h>

#include <assert.h>

#include <string.h>

#include "lens_enum.h"

#include "lens_default.h"

#include "value.h"

#include "sysdep.h"

#include "type.h"

struct enum_entry {

	char *key;

	int own_key;

	struct value *value;

	int own_value;

};

static void

enum_entry_dtor(struct enum_entry *entry, void *data)

{

	if (entry->own_key)

		free(entry->key);

	if (entry->own_value) {

		value_destroy(entry->value);

		free(entry->value);

	}

}

static void

enum_lens_destroy_cb(struct lens *lens)

{

	struct enum_lens *self = (void *)lens;

	VECT_DESTROY(&self->entries, struct enum_entry,

		     enum_entry_dtor, NULL);

}

enum {

#ifdef ARCH_ENDIAN_BIG

	big_endian = 1,

#elif defined (ARCH_ENDIAN_LITTLE)

	big_endian = 0,

#else

# error Undefined endianness.

#endif

};

/* Returns 0 if they are not equal, >0 if they are, and <0 if there

 * was an error.  */

static int

enum_values_equal(struct value *inf_value, struct value *enum_value,

		  struct value_dict *arguments)

{

	/* Width may not match between what's defined in config file

	 * and what arrives from the back end.  Typically, if there is

	 * a mismatch, the config file size will be larger, as we are

	 * in a situation where 64-bit tracer traces 32-bit process.

	 * But opposite situation can occur e.g. on PPC, where it's

	 * apparently possible for 32-bit tracer to trace 64-bit

	 * inferior, or hypothetically in a x32/x86_64 situation.  */

	unsigned char *inf_data = value_get_data(inf_value, arguments);

	size_t inf_sz = value_size(inf_value, arguments);

	if (inf_data == NULL || inf_sz == (size_t)-1)

		return -1;

	assert(inf_value->type->type == enum_value->type->type);

	unsigned char *enum_data = value_get_data(enum_value, arguments);

	size_t enum_sz = value_size(enum_value, arguments);

	if (enum_data == NULL || enum_sz == (size_t)-1)

		return -1;

	size_t sz = enum_sz > inf_sz ? inf_sz : enum_sz;

	if (big_endian)

		return memcmp(enum_data + enum_sz - sz,

			      inf_data + inf_sz - sz, sz) == 0;

	else

		return memcmp(enum_data, inf_data, sz) == 0;

}

static const char *

enum_get(struct enum_lens *lens, struct value *value,

	 struct value_dict *arguments)

{

	size_t i;

	for (i = 0; i < vect_size(&lens->entries); ++i) {

		struct enum_entry *entry = VECT_ELEMENT(&lens->entries,

							struct enum_entry, i);

		int st = enum_values_equal(value, entry->value, arguments);

		if (st < 0)

			return NULL;

		else if (st != 0)

			return entry->key;

	}

	return NULL;

}

static int

enum_lens_format_cb(struct lens *lens, FILE *stream,

		    struct value *value, struct value_dict *arguments)

{

	struct enum_lens *self = (void *)lens;

	const char *name = enum_get(self, value, arguments);

	if (name != NULL)

		return fprintf(stream, "%s", name);

	return lens_format(&default_lens, stream, value, arguments);

}

void

lens_init_enum(struct enum_lens *lens)

{

	*lens = (struct enum_lens){

		{

			.format_cb = enum_lens_format_cb,

			.destroy_cb = enum_lens_destroy_cb,

		},

	};

	VECT_INIT(&lens->entries, struct enum_entry);

}

int

lens_enum_add(struct enum_lens *lens,

	      const char *key, int own_key,

	      struct value *value, int own_value)

{

	struct enum_entry entry = { (char *)key, own_key, value, own_value };

	return VECT_PUSHBACK(&lens->entries, &entry);

}

size_t

lens_enum_size(struct enum_lens *lens)

{

	return vect_size(&lens->entries);

}