d9d6469422
The debuginfo analyses are written with the assumption that the order of instructions in the VCode is the order of instructions in the final machine ocde. This was previously a strong invariant, until we introduced support for cold blocks. Cold blocks are implemented by reordering during emission, because the VCode ordering has other requirements related to lowering (respecting def-use dependencies in the reverse pass), so it is much simpler to reorder instructions at the last moment. Unfortunately, this causes the breakage we now see. This commit fixes the issue by skipping all cold instructions when emitting value-label ranges (which are translated into debuginfo). This means that variables defined in cold blocks will not have DWARF metadata. But cold blocks are usually compiler-inserted slowpaths, not user code, so this is probably OK. Debuginfo is always best-effort, so in any case this does not violate any correctness constraints.
This crate contains the core Cranelift code generator. It translates code from an intermediate representation into executable machine code.