198445 2019-05-31 17:34:58 -0700 [WHLSL] Variant + placement new => have a bad time 2019-07-16 14:00:39 -0700 1 1 1 Unclassified WebKit WebGPU WebKit Nightly Build Unspecified Unspecified RESOLVED DUPLICATE 199726 P2 Normal --- 199726 1 saam saam fpizlo jonlee justin_fan mmaxfield rmorisset oldest_to_newest 1540910 0 saam 2019-05-31 17:34:58 -0700 Think about for loop, it has Variant<VariableDeclarationsStatement, Expression> However, we have passes that replace VariableDeclarationsStatement with Statement. So that breaks the type safety of ForLoop. It seems like the only sensible thing is either forbid replacing certain AST nodes, or only use the more general Expression/Statement. 1551941 1 rmorisset 2019-07-10 18:50:45 -0700 Actually there is another option here: just follow the spec that says that for (X ; e1 ; e2) s is actually syntactic sugar for { X; for(; e1 ; e2) s } This should be very easy to do in the parser, would simplify all code that touches for loops (since there is no more initializer to deal with), and the parser can either put the VariableDeclarationsStatement directly into the block, or if it is an expression wrap it in EffectfulExpressionStatement. 1553307 2 rmorisset 2019-07-16 14:00:39 -0700 Was fixed in 199726. *** This bug has been marked as a duplicate of bug 199726 ***