# General
- Additional logging enabled for fragment autocomplete.
## Roundtrippable AST
- Add a new `AstNode`, `AstGenericType`
- Retain source information for `AstExprTypeAssertion`
## New Type Solver
- New non-strict mode will report unknown symbol errors, e.g
```
foo = 5
local wrong1 = foob <- issue warning
```
- Fixed a bug where new non-strict mode failed to visit large parts of
the program.
- We now infer the types of unnanotated local variables in statements
with multiple assignments, e.g. `local x: "a", y, z = "a", f()`
- Fixed bugs in constraint dispatch ordering.
- Fixed a bug that caused an infinite loop between `Subtyping`,
`OverloadResolution`, and `Type Function Reduction`, by preventing calls
to `Type Function Reduction` being re-entrant.
- Fixed a crash in bidirectional type inference caused by asserting read
and write properties on a type that was readonly.
## Runtime
- Fix a stack overflow caused by `luaL_checkstack` consuming stack space
even if the function fails to reserve memory.
- Using '%c' with a 0 value in Luau string.format will append a '\0'.
Resolves https://github.com/luau-lang/luau/issues/1650
## Miscellaneous
- Miscellaneous small bugfixes for the new solver.
**Full Changelog**:
https://github.com/luau-lang/luau/compare/0.660...0.661
----
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Talha Pathan <tpathan@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>
---------
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Varun Saini <61795485+vrn-sn@users.noreply.github.com>
Co-authored-by: Alexander Youngblood <ayoungblood@roblox.com>
Co-authored-by: Menarul Alam <malam@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
## What's Changed
General performance improvements and bug fixes. `lua_clonetable` was
added too.
### General
## Runtime
- Improvements were made to Luau's performance, including a
`lua_clonetable` function and optimizations to string caching. Buffer
read/write operations were optimized for big-endian machines.
## New Solver
- Crashes related to duplicate keys in table literals, fragment AC
crashes, and potential hash collisions in the StringCache.
- We now handle user-defined type functions as opaque and track interior
free table types.
## Require By String
- Require-by-string path resolution was simplified.
**Full Changelog**:
https://github.com/luau-lang/luau/compare/0.658...0.659
---
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Co-authored-by: Varun Saini <vsaini@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Yohoo Lin <yohoo@roblox.com>
---------
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Varun Saini <61795485+vrn-sn@users.noreply.github.com>
Co-authored-by: Alexander Youngblood <ayoungblood@roblox.com>
benchmark / callgrind (map[branch:main name:luau-lang/benchmark-data], ubuntu-22.04) (push) Has been cancelled
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## General
- Fix a parsing bug related to the starting position of function names.
- Rename Luau's `Table` struct to `LuaTable`.
## New Solver
- Add support for generics in user-defined type functions
([RFC](https://rfcs.luau.org/support-for-generic-function-types-in-user-defined-type-functions.html)).
- Provide a definition of `math.lerp` to the typechecker.
- Implement error suppression in `string.format`.
- Fixes#1587.
- Ensure function call discriminant types are always filled when
resolving `FunctionCallConstraint`.
---
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Talha Pathan <tpathan@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
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# General
All code has been re-formatted by `clang-format`; this is not
mechanically enforced, so Luau may go out-of-sync over the course of the
year.
# New Solver
* Track free types interior to a block of code on `Scope`, which should
reduce the number of free types that remain un-generalized after type
checking is complete (e.g.: less errors like `'a <: number is
incompatible with number`).
# Autocomplete
* Fragment autocomplete now does *not* provide suggestions within
comments (matching non-fragment autocomplete behavior).
* Autocomplete now respects iteration and recursion limits (some hangs
will now early exit with a "unification too complex error," some crashes
will now become internal complier exceptions).
# Runtime
* Add a limit to how many Luau codegen slot nodes addresses can be in
use at the same time (fixes#1605, fixes#1558).
* Added constant folding for vector arithmetic (fixes#1553).
* Added support for `buffer.readbits` and `buffer.writebits` (see:
https://github.com/luau-lang/rfcs/pull/18).
---
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
benchmark / callgrind (map[branch:main name:luau-lang/benchmark-data], ubuntu-22.04) (push) Has been cancelled
build / macos (push) Has been cancelled
build / macos-arm (push) Has been cancelled
build / ubuntu (push) Has been cancelled
build / windows (Win32) (push) Has been cancelled
build / windows (x64) (push) Has been cancelled
build / coverage (push) Has been cancelled
build / web (push) Has been cancelled
release / macos (push) Has been cancelled
release / ubuntu (push) Has been cancelled
release / windows (push) Has been cancelled
release / web (push) Has been cancelled
## New Solver
* Type functions should be able to signal whether or not irreducibility
is due to an error
* Do not generate extra expansion constraint for uninvoked user-defined
type functions
* Print in a user-defined type function reports as an error instead of
logging to stdout
* Many e-graphs bugfixes and performance improvements
* Many general bugfixes and improvements to the new solver as a whole
* Fixed issue with used-defined type functions not being able to call
each other
* Infer types of globals under new type solver
## Fragment Autocomplete
* Miscellaneous fixes to make interop with the old solver better
## Runtime
* Support disabling specific built-in functions from being fast-called
or constant-evaluated (Closes#1538)
* New compiler option `disabledBuiltins` accepts a list of library
function names like "tonumber" or "math.cos"
* Added constant folding for vector arithmetic
* Added constant propagation and type inference for vector globals
(Fixes#1511)
* New compiler option `librariesWithKnownMembers` accepts a list of
libraries for members of which a request for constant value and/or type
will be made
* `libraryMemberTypeCb` callback is called to get the type of a global,
return one of the `LuauBytecodeType` values. 'boolean', 'number',
'string' and 'vector' type are supported.
* `libraryMemberConstantCb` callback is called to setup the constant
value of a global. To set a value, C API `luau_set_compile_constant_*`
or C++ API `setCompileConstant*` functions should be used.
---
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: Daniel Angel <danielangel@roblox.com>
Co-authored-by: Jonathan Kelaty <jkelaty@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>
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>
Co-authored-by: Junseo Yoo <jyoo@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Varun Saini <61795485+vrn-sn@users.noreply.github.com>
Co-authored-by: Alexander Youngblood <ayoungblood@roblox.com>
Co-authored-by: Varun Saini <vsaini@roblox.com>
Co-authored-by: Andrew Miranti <amiranti@roblox.com>
Co-authored-by: Shiqi Ai <sai@roblox.com>
Co-authored-by: Yohoo Lin <yohoo@roblox.com>
Co-authored-by: Daniel Angel <danielangel@roblox.com>
Co-authored-by: Jonathan Kelaty <jkelaty@roblox.com>
# What's Changed
* Support dead store elimination for `STORE_VECTOR` instruction
* Fix parser hang when a separator is used between Luau class
declaration properties
* Provide properties and metatable for built-in vector type definition
to fix type errors
* Fix Fragment Autocomplete to ensure correct parentheses insertion
behavior.
* Add support for 'thread' and 'buffer' primitive types in user-defined
type functions
---------
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@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>
In this update, we continue to improve the overall stability of the new
type solver. We're also shipping some early bits of two new features,
one of the language and one of the analysis API: user-defined type
functions and an incremental typechecking API.
If you use the new solver and want to use all new fixes included in this
release, you have to reference an additional Luau flag:
```c++
LUAU_DYNAMIC_FASTINT(LuauTypeSolverRelease)
```
And set its value to `645`:
```c++
DFInt::LuauTypeSolverRelease.value = 645; // Or a higher value for future updates
```
## New Solver
* Fix a crash where scopes are incorrectly accessed cross-module after
they've been deallocated by appropriately zeroing out associated scope
pointers for free types, generic types, table types, etc.
* Fix a crash where we were incorrectly caching results for bound types
in generalization.
* Eliminated some unnecessary intermediate allocations in the constraint
solver and type function infrastructure.
* Built some initial groundwork for an incremental typecheck API for use
by language servers.
* Built an initial technical preview for [user-defined type
functions](https://rfcs.luau-lang.org/user-defined-type-functions.html),
more work still to come (including calling type functions from other
type functions), but adventurous folks wanting to experiment with it can
try it out by enabling `FFlag::LuauUserDefinedTypeFunctionsSyntax` and
`FFlag::LuauUserDefinedTypeFunction` in their local environment. Special
thanks to @joonyoo181 who built up all the initial infrastructure for
this during his internship!
## Miscellaneous changes
* Fix a compilation error on Ubuntu (fixes#1437)
---
Internal Contributors:
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@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: 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>
