Re: 7.1 extension writing, output parameter remains unchanged

Hi

Hi Jan 2017-07-19 12:17 GMT+02:00 Jan Vávra <vavra@602.cz>:

Hello, I'm porting our extension from php5.6 to php7.1 x64 Windows, Visual Studio 2015. I'd like to write an extension function that has one input / output parameter type of long. But the parameter value changed in extension is not changed in php. What I'm doing wrong? The php code is: $a = 3; $r = hello_square($a); var_export($a); echo "\n"; //value of $a still remains 3, should be 9. The c code is: PHP_FUNCTION(hello_square) { long a = 0; zval *b; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z", &b) == FAILURE) {

     return;

} a = Z_LVAL_P(b); ZVAL_LONG(b, a*a); RETURN_BOOL(1); } ---- I also implemented hello_square this way PHP_FUNCTION(hello_square) { zend_long b; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "l", &b) == FAILURE) {

     return;

} b = b * b; RETURN_BOOL(1); } And the value of $a remains unchanged.

What you should do is to make the parameter sent to hello_square() a reference, this is done by the following (keep in mind this uses the new and fast parameter parsing API, but it is still do-able with the old zend_parse_parameters()): https://gist.github.com/KalleZ/69f9ca1895bcac945e110b7777104203 Take a look at the README.PARAMETER_PARSING_API in the root of php-src, this includes all possible values that zend_parse_parameters() can accept I've fixed line 10 from your sample to

ZVAL_LONG(b, Z_LVAL_P(b) * Z_LVAL_P(b)); or put a constant ZVAL_LONG(b, 20); But in php $a variable remains unchanged. Full c source is: PHP_FUNCTION(hello_square) { zval *b; ZEND_PARSE_PARAMETERS_START(1, 1) Z_PARAM_ZVAL_DEREF(b) ZEND_PARSE_PARAMETERS_END(); zval_dtor(b); ZVAL_LONG(b, Z_LVAL_P(b) * Z_LVAL_P(b)); RETURN_TRUE; } Jan.