## What's new?
* Add support for mixed-mode type checking, which allows modules checked
in the old type solver to be checked and autocompleted by the new one.
* Generalize `RequireResolver` to support require-by-string semantics in
`luau-analyze`.
* Fix a bug in incremental autocomplete where `DefId`s associated with
index expressions were not correctly picked up.
* Fix a bug that prevented "complex" types in generic parameters (for
example, `local x: X<(() -> ())?>`).
### Issues fixed
* #1507
* #1518
---
Internal Contributors:
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Varun Saini <vsaini@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
* New `vector` library! See https://rfcs.luau.org/vector-library.html
for details
* Replace the use of non-portable `strnlen` with `memchr`. `strnlen` is
not part of any C or C++ standard.
* Introduce `lua_newuserdatataggedwithmetatable` for faster tagged
userdata creation of userdata with metatables registered with
`lua_setuserdatametatable`
Old Solver
* It used to be the case that a module's result type would
unconditionally be inferred to be `any` if it imported any module that
participates in any import cycle. This is now fixed.
New Solver
* Improve inference of `table.freeze`: We now infer read-only properties
on tables after they have been frozen.
* We now correctly flag cases where `string.format` is called with 0
arguments.
* Fix a bug in user-defined type functions where table properties could
be lost if the table had a metatable
* Reset the random number seed for each evaluation of a type function
* We now retry subtyping arguments if it failed due to hidden variadics.
---------
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Co-authored-by: Junseo Yoo <jyoo@roblox.com>
### What's new
* Light update this week, mostly fast flag cleanups.
### New Solver
* Rename flag to enable new solver from
`DebugLuauDeferredConstraintResolution` to `LuauSolverV2`
* Added support for magic functions for the new type checker (as opposed
to the type inference component)
* Improved handling of `string.format` with magic function improvements
* Cleaning up some of the reported errors by the new type checker
* Minor refactoring of `TypeChecker2.cpp` that happens to make the diff
very hard to read.
---
### Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
---------
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Co-authored-by: Junseo Yoo <jyoo@roblox.com>
New Solver
* Fix some type inference issues surrounding updates to upvalues eg
```luau
local x = 0
function f()
x = x + 1
end
```
* User-defined type function progress
* Bugfixes for normalization of negated class types. eg `SomeClass &
(class & ~SomeClass)`
* Fixes to subtyping between tables and the top `table` type.
---------
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Co-authored-by: Junseo Yoo <jyoo@roblox.com>
# What's Changed?
- Code refactoring with a new clang-format
- More bug fixes / test case fixes in the new solver
## New Solver
- More precise telemetry collection of `any` types
- Simplification of two completely disjoint tables combines them into a
single table that inherits all properties / indexers
- Refining a `never & <anything>` does not produce type family types nor
constraints
- Silence "inference failed to complete" error when it is the only error
reported
---
### Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Dibri Nsofor <dnsofor@roblox.com>
Co-authored-by: Jeremy Yoo <jyoo@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
---------
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
### What's new?
* Remove a case of unsound `table.move` optimization
* Add Luau stack slot reservations that were missing in REPL (fixes
#1273)
### New Type Solver
* Assignments have been completely reworked to fix a case of cyclic
constraint dependency
* When indexing, if the fresh type's upper bound already contains a
compatible indexer, do not add another upper bound
* Distribute type arguments over all type families sans `eq`, `keyof`,
`rawkeyof`, and other internal type families
* Fix a case where `buffers` component weren't read in two places (fixes
#1267)
* Fix a case where things that constitutes a strong ref were slightly
incorrect
* Fix a case where constraint dependencies weren't setup wrt `for ...
in` statement
### Native Codegen
* Fix an optimization that splits TValue store only when its value and
its tag are compatible
* Implement a system to plug additional type information for custom host
userdata types
---
### Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
---------
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
### What's new?
* Removed new `table.move` optimization because of correctness problems.
### New Type Solver
* Improved error messages for type families to describe what's wrong in
more detail, and ideally without using the term `type family` at all.
* Change `boolean` and `string` singletons in type checking to report
errors to the user when they've gotten an impossible type (indicating a
type error from their context).
* Split debugging flags for type family reduction
(`DebugLuauLogTypeFamilies`) from general solver logging
(`DebugLuauLogSolver`).
* Improve type simplification to support patterns like `(number |
string) | (string | number)` becoming `number | string`.
### Native Code Generation
* Use templated `luaV_doarith` to speedup vector operation fallbacks.
* Various small changes to better support arm64 on Windows.
### Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: James McNellis <jmcnellis@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
---------
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
# What's changed?
* Support for new 'require by string' RFC with relative paths and
aliases in now enabled in Luau REPL application
### New Type Solver
* Fixed assertion failure on generic table keys (`[expr] = value`)
* Fixed an issue with type substitution traversing into the substituted
parts during type instantiation
* Fixed crash in union simplification when that union contained
uninhabited unions and other types inside
* Union types in binary type families like `add<a | b, c>` are expanded
into `add<a, c> | add<b, c>` to handle
* Added handling for type family solving creating new type families
* Fixed a bug with normalization operation caching types with unsolved
parts
* Tables with uninhabited properties are now simplified to `never`
* Fixed failures found by fuzzer
### Native Code Generation
* Added support for shared code generation between multiple Luau VM
instances
* Fixed issue in load-store propagation and new tagged LOAD_TVALUE
instructions
* Fixed issues with partial register dead store elimination causing
failures in GC assists
---
### Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: James McNellis <jmcnellis@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
# What's changed
### Debugger
* Values after a 'continue' statement should not be accessible by
debugger in the 'until' condition
### New Type Solver
* Many fixes to crashes and hangs
* Better bidirectional inference of table literal expressions
### Native Code Generation
* Initial steps toward a shared code allocator
---
### Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
# What's Changed
* Fix a case where the stack wasn't completely cleaned up where
`debug.info` errored when passed `"f"` option and a thread.
* Fix a case of uninitialized field in `luaF_newproto`.
### New Type Solver
* When a local is captured in a function, don't add a new entry to the
`DfgScope::bindings` if the capture occurs within a loop.
* Fix a poor performance characteristic during unification by not trying
to simplify an intersection.
* Fix a case of multiple constraints mutating the same blocked type
causing incorrect inferences.
* Fix a case of assertion failure when overload resolution encounters a
return typepack mismatch.
* When refining a property of the top `table` type, we no longer signal
an unknown property error.
* Fix a misuse of free types when trying to infer the type of a
subscript expression.
* Fix a case of assertion failure when trying to resolve an overload
from `never`.
### Native Code Generation
* Fix dead store optimization issues caused by partial stores.
---
### Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
---------
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
# What's Changed
* Add a compiler hint to improve Luau memory allocation inlining
### New Type Solver
* Added a system for recommending explicit type annotations to users in
cases where we've inferred complex generic types with type families.
* Marked string library functions as `@checked` for use in new
non-strict mode.
* Fixed a bug with new non-strict mode where we would incorrectly report
arity mismatches when missing optional arguments.
* Implement an occurs check for unifications that would produce
self-recursive types.
* Fix bug where overload resolution would fail when applied to
non-overloaded functions.
* Fix bug that caused the subtyping to report an error whenever a
generic was instantiated in an invariant context.
* Fix crash caused by `SetPropConstraint` not blocking properly.
### Native Code Generation
* Implement optimization to eliminate dead stores
* Optimize vector ops for X64 when the source is computed (thanks,
@zeux!)
* Use more efficient lowering for UNM_* (thanks, @zeux!)
---
### Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
---------
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
# What's changed?
* Luau allocation scheme was changed to handle allocations in 513-1024
byte range internally without falling back to global allocator
* coroutine/thread creation no longer requires any global allocations,
making it up to 15% faster (vs libc malloc)
* table construction for 17-32 keys or 33-64 array elements is up to 30%
faster (vs libc malloc)
### New Type Solver
* Cyclic unary negation type families are reduced to `number` when
possible
* Class types are skipped when searching for free types in unifier to
improve performance
* Fixed issues with table type inference when metatables are present
* Improved inference of iteration loop types
* Fixed an issue with bidirectional inference of method calls
* Type simplification will now preserve error suppression markers
### Native Code Generation
* Fixed TAG_VECTOR skip optimization to not break instruction use counts
(broken optimization wasn't included in 614)
* Fixed missing side-effect when optimizing generic loop preparation
instruction
---
### Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
---------
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
# What's changed?
Add program argument passing to scripts run using the Luau REPL! You can
now pass `--program-args` (or shorthand `-a`) to the REPL which will
treat all remaining arguments as arguments to pass to executed scripts.
These values can be accessed through variadic argument expansion. You
can read these values like so:
```
local args = {...} -- gets you an array of all the arguments
```
For example if we run the following script like `luau test.lua -a test1
test2 test3`:
```
-- test.lua
print(...)
```
you should get the output:
```
test1 test2 test3
```
### Native Code Generation
* Improve A64 lowering for vector operations by using vector
instructions
* Fix lowering issue in IR value location tracking!
- A developer reported a divergence between code run in the VM and
Native Code Generation which we have now fixed
### New Type Solver
* Apply substitution to type families, and emit new constraints to
reduce those further
* More progress on reducing comparison (`lt/le`)type families
* Resolve two major sources of cyclic types in the new solver
### Miscellaneous
* Turned internal compiler errors (ICE's) into warnings and errors
-------
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
---------
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
# What's changed?
- Record the location of properties for table types (closes#802)
- Implement stricter UTF-8 validations as per the RFC
(https://github.com/luau-lang/rfcs/pull/1)
- Implement `buffer` as a new type in both the old and new solvers.
- Changed errors produced by some `buffer` builtins to be a bit more
generic to avoid platform-dependent error messages.
- Fixed a bug where `Unifier` would copy some persistent types, tripping
some internal assertions.
- Type checking rules on relational operators is now a little bit more
lax.
- Improve dead code elimination for some `if` statements with complex
always-false conditions
## New type solver
- Dataflow analysis now generates phi nodes on exit of branches.
- Dataflow analysis avoids producing a new definition for locals or
properties that are not owned by that loop.
- If a function parameter has been constrained to `never`, report errors
at all uses of that parameter within that function.
- Switch to using the new `Luau::Set` to replace `std::unordered_set` to
alleviate some poor allocation characteristics which was negatively
affecting overall performance.
- Subtyping can now report many failing reasons instead of just the
first one that we happened to find during the test.
- Subtyping now also report reasons for type pack mismatches.
- When visiting `if` statements or expressions, the resulting context
are the common terms in both branches.
## Native codegen
- Implement support for `buffer` builtins to its IR for x64 and A64.
- Optimized `table.insert` by not inserting a table barrier if it is
fastcalled with a constant.
## Internal Contributors
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Arseny Kapoulkine <arseny@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
* Fix a use-after-free bug in the new type cloning algorithm
* Tighten up the type of `coroutine.wrap`. It is now `<A..., R...>(f:
(A...) -> R...) -> ((A...) -> R...)`
* Break `.luaurc` out into a separate library target `Luau.Config`. This
makes it easier for applications to reason about config files without
also depending on the type inference engine.
* Move typechecking limits into `FrontendOptions`. This allows embedders
more finely-grained control over autocomplete's internal time limits.
* Fix stability issue with debugger onprotectederror callback allowing
break in non-yieldable contexts
New solver:
* Initial work toward [Local Type
Inference](0e1082108f/rfcs/local-type-inference.md)
* Introduce a new subtyping test. This will be much nicer than the old
test because it is completely separate both from actual type inference
and from error reporting.
Native code generation:
* Added function to compute iterated dominance frontier
* Optimize barriers in SET_UPVALUE when tag is known
* Cache lua_State::global in a register on A64
* Optimize constant stores in A64 lowering
* Track table array size state to optimize array size checks
* Add split tag/value store into a VM register
* Check that spills can outlive the block only in specific conditions
---------
Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
* Progress toward a diffing algorithm for types. We hope that this will
be useful for writing clearer error messages.
* Add a missing recursion limiter in `Unifier::tryUnifyTables`. This was
causing a crash in certain situations.
* Luau heap graph enumeration improvements:
* Weak references are not reported
* Added tag as a fallback name of non-string table links
* Included top Luau function information in thread name to understand
where thread might be suspended
* Constant folding for `math.pi` and `math.huge` at -O2
* Optimize `string.format` and `%*`
* This change makes string interpolation 1.5x-2x faster depending on the
number and type of formatted components, assuming a few are using
primitive types, and reduces associated GC pressure.
New type checker:
* Initial work toward tracking the upper and lower bounds of types
accurately.
Native code generation (JIT):
* Add IrCmd::CHECK_TRUTHY for improved assert fast-calls
* Do not compute type map for modules without types
* Capture metatable+readonly state for NEW_TABLE IR instructions
* Replace JUMP_CMP_ANY with CMP_ANY and existing JUMP_EQ_INT
* Add support for exits to VM with reentry lock in VmExit
---------
Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Type checker/autocomplete:
* `Luau::autocomplete` no longer performs typechecking internally, make
sure to run `Frontend::check` before performing autocomplete requests
* Autocomplete string suggestions without "" are now only suggested
inside the ""
* Autocomplete suggestions now include `function (anonymous autofilled)`
key with a full suggestion for the function expression (with arguments
included) stored in `AutocompleteEntry::insertText`
* `AutocompleteEntry::indexedWithSelf` is provided for function call
suggestions made with `:`
* Cyclic modules now see each other type exports as `any` to prevent
memory use-after-free (similar to module return type)
Runtime:
* Updated inline/loop unroll cost model to better handle assignments
(Fixes https://github.com/Roblox/luau/issues/978)
* `math.noise` speed was improved by ~30%
* `table.concat` speed was improved by ~5-7%
* `tonumber` and `tostring` now have fastcall paths that execute ~1.5x
and ~2.5x faster respectively (fixes#777)
* Fixed crash in `luaL_typename` when index refers to a non-existing
value
* Fixed potential out of memory scenario when using `string.sub` or
`string.char` in a loop
* Fixed behavior of some fastcall builtins when called without arguments
under -O2 to match original functions
* Support for native code execution in VM is now enabled by default
(note: native code still has to be generated explicitly)
* `Codegen::compile` now accepts `CodeGen_OnlyNativeModules` flag. When
set, only modules that have a `--!native` hot-comment at the top will be
compiled to native code
In our new typechecker:
* Generic type packs are no longer considered to be variadic during
unification
* Timeout and cancellation now works in new solver
* Fixed false positive errors around 'table' and 'function' type
refinements
* Table literals now use covariant unification rules. This is sound
since literal has no type specified and has no aliases
* Fixed issues with blocked types escaping the constraint solver
* Fixed more places where error messages that should've been suppressed
were still reported
* Fixed errors when iterating over a top table type
In our native code generation (jit):
* 'DebugLuauAbortingChecks' flag is now supported on A64
* LOP_NEWCLOSURE has been translated to IR
* Definition files can now ascribe indexers to class types.
(https://github.com/Roblox/luau/pull/949)
* Remove --compile support from the REPL. You can just use luau-compile
instead.
* When an exception is thrown during parallel typechecking (usually an
ICE), we now gracefully stop typechecking and drain active workers
before rethrowing the exception.
New solver
* Include more source location information when we hit an internal
compiler error
* Improve the logic that simplifies intersections of tables
JIT
* Save testable type annotations to bytecode
* Improve block placement for linearized blocks
* Add support for lea reg, [rip+offset] for labels
* Unify X64 and A64 codegen for RETURN
* Outline interrupt handlers for X64
* Remove global rArgN in favor of build.abi
* Change A64 INTERRUPT lowering to match X64
---------
Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Lots of things going on this week:
* Fix a crash that could occur in the presence of a cyclic union. We
shouldn't be creating cyclic unions, but we shouldn't be crashing when
they arise either.
* Minor cleanup of `luau_precall`
* Internal change to make L->top handling slightly more uniform
* Optimize SETGLOBAL & GETGLOBAL fallback C functions.
* https://github.com/Roblox/luau/pull/929
* The syntax to the `luau-reduce` commandline tool has changed. It now
accepts a script, a command to execute, and an error to search for. It
no longer automatically passes the script to the command which makes it
a lot more flexible. Also be warned that it edits the script it is
passed **in place**. Do not point it at something that is not in source
control!
New solver
* Switch to a greedier but more fallible algorithm for simplifying union
and intersection types that are created as part of refinement
calculation. This has much better and more predictable performance.
* Fix a constraint cycle in recursive function calls.
* Much improved inference of binary addition. Functions like `function
add(x, y) return x + y end` can now be inferred without annotations. We
also accurately typecheck calls to functions like this.
* Many small bugfixes surrounding things like table indexers
* Add support for indexers on class types. This was previously added to
the old solver; we now add it to the new one for feature parity.
JIT
* https://github.com/Roblox/luau/pull/931
* Fuse key.value and key.tt loads for CEHCK_SLOT_MATCH in A64
* Implement remaining aliases of BFM for A64
* Implement new callinfo flag for A64
* Add instruction simplification for int->num->int conversion chains
* Don't even load execdata for X64 calls
* Treat opcode fallbacks the same as manually written fallbacks
---------
Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
