The aim of this PR is twofold:
- Reduce the number of highly similar TMP|VAR handlers
- Avoid ZVAL_DEREF in most of these cases
This is achieved by guaranteeing that all zend_compile_expr() calls, as well as
all other compile calls with BP_VAR_{R,IS}, will result in a TMP variable. This
implies that the result will not contain an IS_INDIRECT or IS_REFERENCE value,
which was mostly already the case, with two exceptions:
- Calls to return-by-reference functions. Because return-by-reference functions
are quite rare, this is solved by delegating the DEREF to the RETURN_BY_REF
handler, which will examine the stack to check whether the caller expects a
VAR or TMP to understand whether the DEREF is needed. Internal functions will
also need to adjust by calling the zend_return_unwrap_ref() function.
- By-reference assignments, including both $a = &$b, as well as $a = [&$b]. When
the result of these expressions is used in a BP_VAR_R context, the reference
is unwrapped via a ZEND_QM_ASSIGN opcode beforehand. This is exceptionally
rare.
Closes GH-20628
* zend_compile: Fix handling of PFA syntax in array_map() optimization
PFA is not implemented and the syntax is rejected at compile-time, thus it was
assumed the assertion would be unreachable. However the check for PFA syntax
happens after compiling special functions, making it reachable. Fix this by
gracefully returning FAILURE which will then correctly emit the error during
the compilation of the normal call.
Fixesphp/php-src#20991.
* zend_compile: Fix array_map() optimization for dynamic function names
Fixesphp/php-src#20990.
* zend_compile: Adjust array_map() optimization after review feedback
