intval (int)的区别

intval定义

PHP_FUNCTION(intval)
{
	zval **num;
	long arg_base;
	int base;

	switch (ZEND_NUM_ARGS()) {
		case 1:
			if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "Z", &num) == FAILURE) {
				return;
			}
			base = 10;
			break;

		case 2:
			if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "Zl", &num, &arg_base) == FAILURE) {
				return;
			}
			base = arg_base;
			break;

		default:
			WRONG_PARAM_COUNT;
	}

	RETVAL_ZVAL(*num, 1, 0);
	convert_to_long_base(return_value, base); //最终调用了此函数
}



ZEND_API void convert_to_long_base(zval *op, int base) /* {{{ */
{
	long tmp;

	switch (Z_TYPE_P(op)) {
		case IS_NULL:
			Z_LVAL_P(op) = 0;
			break;
		case IS_RESOURCE: {
				TSRMLS_FETCH();

				zend_list_delete(Z_LVAL_P(op));
			}
			/* break missing intentionally */
		case IS_BOOL:
		case IS_LONG:
			break;
		case IS_DOUBLE:
			Z_LVAL_P(op) = zend_dval_to_lval(Z_DVAL_P(op));
			break;
		case IS_STRING:
			{
				char *strval = Z_STRVAL_P(op);

				Z_LVAL_P(op) = strtol(strval, NULL, base);
				STR_FREE(strval);
			}
			break;
		case IS_ARRAY:
			tmp = (zend_hash_num_elements(Z_ARRVAL_P(op))?1:0);
			zval_dtor(op);
			Z_LVAL_P(op) = tmp;
			break;
		case IS_OBJECT:
			{
				int retval = 1;
				TSRMLS_FETCH();

				convert_object_to_type(op, IS_LONG, convert_to_long);

				if (Z_TYPE_P(op) == IS_LONG) {
					return;
				}
				zend_error(E_NOTICE, "Object of class %s could not be converted to int", Z_OBJCE_P(op)->name);

				zval_dtor(op);
				ZVAL_LONG(op, retval);
				return;
			}
		default:
			zend_error(E_WARNING, "Cannot convert to ordinal value");
			zval_dtor(op);
			Z_LVAL_P(op) = 0;
			break;
	}

	Z_TYPE_P(op) = IS_LONG;
}

int 定义

1.词法分析
<ST_IN_SCRIPTING>"("{TABS_AND_SPACES}("int"|"integer"){TABS_AND_SPACES}")" {
	return T_INT_CAST;
}


2.词法分析
%token T_INT_CAST    "(int) (T_INT_CAST)"

expr_without_variable:
		T_LIST '(' { zend_do_list_init(TSRMLS_C); } assignment_list ')' '=' expr { zend_do_list_end(&$$, &$7 TSRMLS_CC); }
	|	variable '=' expr		{ zend_check_writable_variable(&$1); zend_do_assign(&$$, &$1, &$3 TSRMLS_CC); }
	|	variable '=' '&' variable { zend_check_writable_variable(&$1); zend_do_end_variable_parse(&$4, BP_VAR_W, 1 TSRMLS_CC); zend_do_end_variable_parse(&$1, BP_VAR_W, 0 TSRMLS_CC); zend_do_assign_ref(&$$, &$1, &$4 TSRMLS_CC); }
	|	variable '=' '&' T_NEW class_name_reference { zend_error(E_DEPRECATED, "Assigning the return value of new by reference is deprecated");  zend_check_writable_variable(&$1); zend_do_extended_fcall_begin(TSRMLS_C); zend_do_begin_new_object(&$4, &$5 TSRMLS_CC); } ctor_arguments { zend_do_end_new_object(&$3, &$4, &$7 TSRMLS_CC); zend_do_extended_fcall_end(TSRMLS_C); zend_do_end_variable_parse(&$1, BP_VAR_W, 0 TSRMLS_CC); $3.EA = ZEND_PARSED_NEW; zend_do_assign_ref(&$$, &$1, &$3 TSRMLS_CC); }
	|	T_CLONE expr { zend_do_clone(&$$, &$2 TSRMLS_CC); }
	|	variable T_PLUS_EQUAL expr 	{ zend_check_writable_variable(&$1); 
	|	expr '|' expr	{ zend_do_binary_op(ZEND_BW_OR, &$$, &$1, &$3 TSRMLS_CC); }
	|	expr '&' expr	{ zend_do_binary_op(ZEND_BW_AND, &$$, &$1, &$3 TSRMLS_CC); }
	|	expr '^' expr	{ zend_do_binary_op(ZEND_BW_XOR, &$$, &$1, &$3 TSRMLS_CC); }
	|	expr '.' expr 	{ zend_do_binary_op(ZEND_CONCAT, &$$, &$1, &$3 TSRMLS_CC); }
	|	expr '+' expr 	{ zend_do_binary_op(ZEND_ADD, &$$, &$1, &$3 TSRMLS_CC); }
	|	expr '-' expr 	{ zend_do_binary_op(ZEND_SUB, &$$, &$1, &$3 TSRMLS_CC); }
	|	expr '*' expr	{ zend_do_binary_op(ZEND_MUL, &$$, &$1, &$3 TSRMLS_CC); }
	|	expr '/' expr	{ zend_do_binary_op(ZEND_DIV, &$$, &$1, &$3 TSRMLS_CC); }
 
	|	'+' expr %prec T_INC { ZVAL_LONG(&$1.u.constant, 0); if ($2.op_type == IS_CONST) { add_function(&$2.u.constant, &$1.u.constant, &$2.u.constant TSRMLS_CC); $$ = $2; } else { $1.op_type = IS_CONST; INIT_PZVAL(&$1.u.constant); zend_do_binary_op(ZEND_ADD, &$$, &$1, &$2 TSRMLS_CC); } }
	|	'-' expr %prec T_INC { ZVAL_LONG(&$1.u.constant, 0); if ($2.op_type == IS_CONST) { sub_function(&$2.u.constant, &$1.u.constant, &$2.u.constant TSRMLS_CC); $$ = $2; } else { $1.op_type = IS_CONST; INIT_PZVAL(&$1.u.constant); zend_do_binary_op(ZEND_SUB, &$$, &$1, &$2 TSRMLS_CC); } }
	|	'!' expr { zend_do_unary_op(ZEND_BOOL_NOT, &$$, &$2 TSRMLS_CC); }

	|	expr '?' { zend_do_begin_qm_op(&$1, &$2 TSRMLS_CC); }
		expr ':' { zend_do_qm_true(&$4, &$2, &$5 TSRMLS_CC); }
		expr	 { zend_do_qm_false(&$$, &$7, &$2, &$5 TSRMLS_CC); }
	|	expr '?' ':' { zend_do_jmp_set(&$1, &$2, &$3 TSRMLS_CC); }
		expr     { zend_do_jmp_set_else(&$$, &$5, &$2, &$3 TSRMLS_CC); }
	|	internal_functions_in_yacc { $$ = $1; }
	
	
	
	//(int)$a 的语法分析 ,调用了 zend_do_cast 
	|	T_INT_CAST expr 	{ zend_do_cast(&$$, &$2, IS_LONG TSRMLS_CC); }
	
	
	
	
	|	T_DOUBLE_CAST expr 	{ zend_do_cast(&$$, &$2, IS_DOUBLE TSRMLS_CC); }
	|	T_STRING_CAST expr	{ zend_do_cast(&$$, &$2, IS_STRING TSRMLS_CC); }
	|	T_ARRAY_CAST expr 	{ zend_do_cast(&$$, &$2, IS_ARRAY TSRMLS_CC); }
	|	T_OBJECT_CAST expr 	{ zend_do_cast(&$$, &$2, IS_OBJECT TSRMLS_CC); }
	|	T_BOOL_CAST expr	{ zend_do_cast(&$$, &$2, IS_BOOL TSRMLS_CC); }
	|	T_UNSET_CAST expr	{ zend_do_cast(&$$, &$2, IS_NULL TSRMLS_CC); }
	|	T_EXIT exit_expr	{ zend_do_exit(&$$, &$2 TSRMLS_CC); }
|	T_OBJECT_CAST expr 	{ zend_do_cast(&$$, &$2, IS_OBJECT TSRMLS_CC); }



3.设置opcode
void zend_do_cast(znode *result, const znode *expr, int type TSRMLS_DC) /* {{{ */
{
	zend_op *opline = get_next_op(CG(active_op_array) TSRMLS_CC);

	opline->opcode = ZEND_CAST;
	opline->result_type = IS_TMP_VAR;
	opline->result.var = get_temporary_variable(CG(active_op_array));
	SET_NODE(opline->op1, expr);
	SET_UNUSED(opline->op2);
	opline->extended_value = type;
	GET_NODE(result, opline->result);
}

4. ZEND_CAST  opcode 映射函数

static int ZEND_FASTCALL  ZEND_CAST_SPEC_CV_HANDLER(ZEND_OPCODE_HANDLER_ARGS)
{
	USE_OPLINE

	zval *expr;
	zval *result = &EX_T(opline->result.var).tmp_var;

	SAVE_OPLINE();
	expr = _get_zval_ptr_cv_BP_VAR_R(execute_data, opline->op1.var TSRMLS_CC);

	if (opline->extended_value != IS_STRING) {
		ZVAL_COPY_VALUE(result, expr);
		if (!0) {
			zendi_zval_copy_ctor(*result);
		}
	}
	switch (opline->extended_value) {
		case IS_NULL:
			convert_to_null(result);
			break;
		case IS_BOOL:
			convert_to_boolean(result);
			break;
		case IS_LONG:
			convert_to_long(result);  //调用了此函数
			break;
		case IS_DOUBLE:
			convert_to_double(result);
			break;
		case IS_STRING: {
			zval var_copy;
			int use_copy;

			zend_make_printable_zval(expr, &var_copy, &use_copy);
			if (use_copy) {
				ZVAL_COPY_VALUE(result, &var_copy);
				if (0) {

				}
			} else {
				ZVAL_COPY_VALUE(result, expr);
				if (!0) {
					zendi_zval_copy_ctor(*result);
				}
			}
			break;
		}
		case IS_ARRAY:
			convert_to_array(result);
			break;
		case IS_OBJECT:
			convert_to_object(result);
			break;
	}

	CHECK_EXCEPTION();
	ZEND_VM_NEXT_OPCODE();
}

5.
ZEND_API void convert_to_long(zval *op) /* {{{ */
{
	if (Z_TYPE_P(op) != IS_LONG) {
		convert_to_long_base(op, 10);  //发现最后也调用了convert_to_long_base
	}
}

由此可见他们最终调用的是同一函数。区别是(int)$a 是php内置操作符，预先内置了，而intval是个扩展函数，后面才加载进去的。