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1 Commits (14254995889a199e4d72fa85e256ad2536580432)

Author	SHA1	Message	Date
Alessio Giacobbe	20f0b5a284	fix(codegen): evaluate compound ??= RHS only when the target is not set (#47) ... * fix(codegen): evaluate compound ??= RHS only when the target is not set PHP evaluates the right-hand side of ??= lazily: `$a = 1; $a ??= sideEffect() + 1;` never calls sideEffect(). When the RHS was a compound expression the compiler materialized its lowered statements (the call result temporary) into the enclosing statement context, so the generated C++ executed the side-effecting call unconditionally before the isset check. Generalize the conditional-lambda lowering that already protected native-object targets: whenever the RHS captured before/after statements, emit an immediately-invoked lambda whose not-set branch contains those statements, the assignment and the cleanup. The simple inline form (`$b ??= f()`) keeps its existing conditional-expression codegen unchanged. * fix(codegen): stabilize ??= targets and finish the RHS before assigning Zend evaluates a coalesce-assignment target's receiver and array keys exactly once, before the isset check and regardless of its outcome; the string-based lowering mentioned the target on every use (isset, read, write, returned value), so a side-effecting receiver ran twice when the target was set and three times when it was not. Side-effecting target subexpressions are now materialized into temporaries in source order (array containers keep their original variable — writing through a copied temporary would write to the copy — while object receivers are handles) and the rewritten target reuses them everywhere. The captured branch also assigned the target before running the RHS's deferred write-backs, so a postfix increment on the RHS finished after the outer assignment — observable by a set hook on the target. The RHS now completes into a temporary (write-backs included) before the target is written, and the assignment expression itself is returned so the target is not read again afterwards. * fix(codegen): stabilize every ??= target subexpression, bound temporary lifetimes Three target-stabilization gaps in the coalesce-assignment lowering: - A value-producing array container (makeArray()[keyName()] ??= 42) was left unstabilized: the dimension was materialized first, reversing PHP's container-then-key source order, and the container ran once for the isset check and again for the write. Non-variable containers are now materialized in source order; plain-variable containers keep write-through semantics, and a value-producing container is itself the temporary PHP writes into. - Dynamic property names were re-evaluated on every mention: $box->{propertyName()} ran the name expression twice per branch, and StaticPropertyFetch was not handled at all. Dynamic instance names, static class expressions and static property names are now materialized once, in PHP evaluation order (receiver, name, then dimension), recursively through chained targets. - The materialized temporaries were function-scoped, deferring the receiver's destructor to function exit where PHP destroys it at the end of the statement. Temporaries now follow the established lifetime idiom (stabilizeAssignOpPropertyReceiver): zval-owning Variants are .unset() at statement end and Native pointer temporaries reset to nullptr.	1 month ago