Luau Files

Ding, dong, 🚪 🔔 , what's that, another Luau release???

What's Changed

• Hash TypeId, TypePackId, void and Constraint by address by @Pyseph in https://github.com/luau-lang/luau/pull/3007
• Improve UDTF chunk names in error messages by @PhoenixWhitefire in https://github.com/luau-lang/luau/pull/2434
• Remove loadstring from built-in type definitions by @PhoenixWhitefire in https://github.com/luau-lang/luau/pull/2367
• Optimize string.gsub for patterns without special characters by @gemtool in https://github.com/luau-lang/luau/pull/2988
• Fix grouped error calls in control flow analysis by @Companion in https://github.com/luau-lang/luau/pull/2694
• Update copyright year in LICENSE.txt by @Alexanderfem in https://github.com/luau-lang/luau/pull/2446
• Add link to C API in README by @PhoenixWhitefire in https://github.com/luau-lang/luau/pull/3033
• Fix ~nil refinements of blocked types never simplifying by @haziscool in https://github.com/luau-lang/luau/pull/3027
• Fix assertion in IrAssemblyTest for Windows by @skberkeley in https://github.com/luau-lang/luau/pull/3040

New Contributors

• @Alexanderfem made their first contribution in https://github.com/luau-lang/luau/pull/2446

Analysis

• Stop sharing internal error reporters between threads to avoid data races. Fixes [#3020].
• Implement MLStruct-style unifier rewrite rules. Fixes [#3001], [#3002].
• Cache the absence of type functions for all types involved in InstanceCollector.
• Improve scope handling for strict mode type checker. Fixes [#2991].
• Implement autocomplete for function statements.
• Fix bug in fragment autocomplete and union discriminant recommendation.
• More end-to-end golden tests.

Compiler / NCG

• Mark table as mutable for constant propagation if metamethods are involved.
• Correctly remap CALLFB slot instruction targets in expandJumps.
• Fix LuauCompileMoveElision when current argument target still needs evaluation.
• Fix fuzzer crash where CALLFB Protos were stale.
• NCG: Continue applying possible optimizations when ConstPropState hits a limit.
• NCG: Fix bug in Proto counter logic.
• NCG: Do not mark lazy restore locations as materialized under a conditional spill block.
• NCG: Exit sync anti-clobber restores have to be delayed until after the state synchronization is complete.
• NCG: Do not let buffer offset scale go down to zero.
• NCG: In exit sync, restore registers in rematerializable locations that can be clobbered.

Runtime / C API

• Stop gating coroutine.finally behind a debug flag.
• Allow the Luau finalizer function to only be called once.
• Resume protected calls started by error continuations in Luau.
• Support cancellation in lua_pushfinalizerfunction and fix coroutine.close issues.

Full Changelog: https://github.com/luau-lang/luau/compare/0.741...0.742

Co-authored-by: Alexander Youngblood ayoungblood@roblox.com Co-authored-by: Ariel Weiss arielweiss@roblox.com Co-authored-by: Hunter Goldstein hgoldstein@roblox.com Co-authored-by: Ilya Rezvov irezvov@roblox.com Co-authored-by: Thomas Schollenberger tschollenberger@roblox.com Co-authored-by: Varun Saini vsaini@roblox.com Co-authored-by: Vighnesh Vijay vvijay@roblox.com Co-authored-by: Vyacheslav Egorov vegorov@roblox.com