/*
   +----------------------------------------------------------------------+
   | Zend OPcache                                                         |
   +----------------------------------------------------------------------+
   | Copyright (c) 1998-2013 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Andi Gutmans <andi@zend.com>                                |
   |          Zeev Suraski <zeev@zend.com>                                |
   |          Stanislav Malyshev <stas@zend.com>                          |
   |          Dmitry Stogov <dmitry@zend.com>                             |
   +----------------------------------------------------------------------+
*/

#include "Optimizer/zend_optimizer.h"
#include "Optimizer/zend_optimizer_internal.h"
#include "zend_API.h"
#include "zend_constants.h"
#include "zend_execute.h"
#include "zend_vm.h"

#define OPTIMIZATION_LEVEL \
	ZCG(accel_directives).optimization_level

static void zend_optimizer_zval_dtor_wrapper(zval *zvalue)
{
	zval_dtor(zvalue);
}

static void zend_optimizer_collect_constant(HashTable **constants, zval *name, zval* value)
{
	zval val;

	if (!*constants) {
		*constants = emalloc(sizeof(HashTable));
		zend_hash_init(*constants, 16, NULL, (void (*)(void *))zend_optimizer_zval_dtor_wrapper, 0);
	}
	val = *value;
	zval_copy_ctor(&val);
	zend_hash_add(*constants, Z_STRVAL_P(name), Z_STRLEN_P(name)+1, (void**)&val, sizeof(zval), NULL);
}

static int zend_optimizer_get_collected_constant(HashTable *constants, zval *name, zval* value)
{
	zval *val;

	if (zend_hash_find(constants, Z_STRVAL_P(name), Z_STRLEN_P(name)+1, (void**)&val) == SUCCESS) {
		*value = *val;
		zval_copy_ctor(value);
		return 1;
	}
	return 0;
}

#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
int zend_optimizer_add_literal(zend_op_array *op_array, const zval *zv TSRMLS_DC)
{
	int i = op_array->last_literal;
	op_array->last_literal++;
	op_array->literals = (zend_literal*)erealloc(op_array->literals, op_array->last_literal * sizeof(zend_literal));
	op_array->literals[i].constant = *zv;
	op_array->literals[i].hash_value = 0;
	op_array->literals[i].cache_slot = -1;
	Z_SET_REFCOUNT(op_array->literals[i].constant, 2);
	Z_SET_ISREF(op_array->literals[i].constant);
	return i;
}

# define LITERAL_LONG(op, val) do { \
		zval _c; \
		ZVAL_LONG(&_c, val); \
		op.constant = zend_optimizer_add_literal(op_array, &_c TSRMLS_CC); \
	} while (0)

# define LITERAL_BOOL(op, val) do { \
		zval _c; \
		ZVAL_BOOL(&_c, val); \
		op.constant = zend_optimizer_add_literal(op_array, &_c TSRMLS_CC); \
	} while (0)

# define literal_dtor(zv) do { \
		zval_dtor(zv); \
		Z_TYPE_P(zv) = IS_NULL; \
	} while (0)

#define COPY_NODE(target, src) do { \
		target ## _type = src ## _type; \
		target = src; \
	} while (0)

#else

# define LITERAL_LONG(op, val) ZVAL_LONG(&op.u.constant, val)

# define LITERAL_BOOL(op, val) ZVAL_BOOL(&op.u.constant, val)

# define literal_dtor(zv) zval_dtor(zv)

#define COPY_NODE(target, src) do { \
		target = src; \
	} while (0)

#endif

#include "Optimizer/nop_removal.c"
#include "Optimizer/block_pass.c"
#include "Optimizer/optimize_temp_vars_5.c"
#include "Optimizer/compact_literals.c"
#include "Optimizer/optimize_func_calls.c"

static void zend_optimize(zend_op_array           *op_array,
                          zend_persistent_script  *script,
                          HashTable              **constants TSRMLS_DC)
{
	if (op_array->type == ZEND_EVAL_CODE ||
	    (op_array->fn_flags & ZEND_ACC_INTERACTIVE)) {
		return;
	}

	/* pass 1
	 * - substitute persistent constants (true, false, null, etc)
	 * - perform compile-time evaluation of constant binary and unary operations
	 * - optimize series of ADD_STRING and/or ADD_CHAR
	 * - convert CAST(IS_BOOL,x) into BOOL(x)
	 */
#include "Optimizer/pass1_5.c"

	/* pass 2:
	 * - convert non-numeric constants to numeric constants in numeric operators
	 * - optimize constant conditional JMPs
	 * - optimize static BRKs and CONTs
	 */
#include "Optimizer/pass2.c"

	/* pass 3:
	 * - optimize $i = $i+expr to $i+=expr
	 * - optimize series of JMPs
	 * - change $i++ to ++$i where possible
	 */
#include "Optimizer/pass3.c"

#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
	/* pass 4:
	 * - INIT_FCALL_BY_NAME -> DO_FCALL
	 */
	if (ZEND_OPTIMIZER_PASS_4 & OPTIMIZATION_LEVEL) {
		optimize_func_calls(op_array, script TSRMLS_CC);
	}
#endif

	/* pass 5:
	 * - CFG optimization
	 */
#include "Optimizer/pass5.c"

	/* pass 9:
	 * - Optimize temp variables usage
	 */
#include "Optimizer/pass9.c"

	/* pass 10:
	 * - remove NOPs
	 */
#include "Optimizer/pass10.c"

#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
	/* pass 11:
	 * - Compact literals table 
	 */
	if (ZEND_OPTIMIZER_PASS_11 & OPTIMIZATION_LEVEL) {
		optimizer_compact_literals(op_array TSRMLS_CC);
	}
#endif
}

static void zend_accel_optimize(zend_op_array           *op_array,
                                zend_persistent_script  *script,
                                HashTable              **constants TSRMLS_DC)
{
	zend_op *opline, *end;

	/* Revert pass_two() */
	opline = op_array->opcodes;
	end = opline + op_array->last;
	while (opline < end) {
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
		if (opline->op1_type == IS_CONST) {
			opline->op1.constant = opline->op1.literal - op_array->literals;
		}
		if (opline->op2_type == IS_CONST) {
			opline->op2.constant = opline->op2.literal - op_array->literals;
		}
#endif
		switch (opline->opcode) {
			case ZEND_JMP:
#if ZEND_EXTENSION_API_NO > PHP_5_2_X_API_NO
			case ZEND_GOTO:
#endif
#if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
			case ZEND_FAST_CALL:
#endif
				ZEND_OP1(opline).opline_num = ZEND_OP1(opline).jmp_addr - op_array->opcodes;
				break;
			case ZEND_JMPZ:
			case ZEND_JMPNZ:
			case ZEND_JMPZ_EX:
			case ZEND_JMPNZ_EX:
#if ZEND_EXTENSION_API_NO > PHP_5_2_X_API_NO
			case ZEND_JMP_SET:
#endif
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
			case ZEND_JMP_SET_VAR:
#endif
				ZEND_OP2(opline).opline_num = ZEND_OP2(opline).jmp_addr - op_array->opcodes;
				break;
		}
		opline++;
	}

	/* Do actual optimizations */
	zend_optimize(op_array, script, constants TSRMLS_CC);	
	
	/* Redo pass_two() */
	opline = op_array->opcodes;
	end = opline + op_array->last;
	while (opline < end) {
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
		if (opline->op1_type == IS_CONST) {
			opline->op1.zv = &op_array->literals[opline->op1.constant].constant;
		}
		if (opline->op2_type == IS_CONST) {
			opline->op2.zv = &op_array->literals[opline->op2.constant].constant;
		}
#endif
		switch (opline->opcode) {
			case ZEND_JMP:
#if ZEND_EXTENSION_API_NO > PHP_5_2_X_API_NO
			case ZEND_GOTO:
#endif
#if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
			case ZEND_FAST_CALL:
#endif
				ZEND_OP1(opline).jmp_addr = &op_array->opcodes[ZEND_OP1(opline).opline_num];
				break;
			case ZEND_JMPZ:
			case ZEND_JMPNZ:
			case ZEND_JMPZ_EX:
			case ZEND_JMPNZ_EX:
#if ZEND_EXTENSION_API_NO > PHP_5_2_X_API_NO
			case ZEND_JMP_SET:
#endif
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
			case ZEND_JMP_SET_VAR:
#endif
				ZEND_OP2(opline).jmp_addr = &op_array->opcodes[ZEND_OP2(opline).opline_num];
				break;
		}
		ZEND_VM_SET_OPCODE_HANDLER(opline);
		opline++;
	}
}

int zend_accel_script_optimize(zend_persistent_script *script TSRMLS_DC)
{
	Bucket *p, *q;
	HashTable *constants = NULL;

	zend_accel_optimize(&script->main_op_array, script, &constants TSRMLS_CC);

	p = script->function_table.pListHead;
	while (p) {
		zend_op_array *op_array = (zend_op_array*)p->pData;
		zend_accel_optimize(op_array, script, &constants TSRMLS_CC);
		p = p->pListNext;
	}

	p = script->class_table.pListHead;
	while (p) {
		zend_class_entry *ce = (zend_class_entry*)p->pDataPtr;
		q = ce->function_table.pListHead;
		while (q) {
			zend_op_array *op_array = (zend_op_array*)q->pData;
			if (op_array->scope == ce) {
				zend_accel_optimize(op_array, script, &constants TSRMLS_CC);
			} else if (op_array->type == ZEND_USER_FUNCTION) {
				zend_op_array *orig_op_array;
				if (zend_hash_find(&op_array->scope->function_table, q->arKey, q->nKeyLength, (void**)&orig_op_array) == SUCCESS) {
					HashTable *ht = op_array->static_variables;
					*op_array = *orig_op_array;
					op_array->static_variables = ht;
				}
			}
			q = q->pListNext;
		}
		p = p->pListNext;
	}

	if (constants) {
		zend_hash_destroy(constants);
		efree(constants);
	}

	return 1;
}