## What's Changed?
This week we have an update with an implementation for one of the RFCs
we had approved before, an improvement of the new type solver and a
small Lua 5.1 C API compatibility improvement.
* `@deprecated` attribute can now have a custom suggestion for a
replacement and a reason message as described in [deprecated attribute
parameters
RFC](https://rfcs.luau.org/syntax-attribute-functions-deprecated.html)
For example:
```luau
@[deprecated {reason = "foo suffers from performance issues", use = "bar"}]
local function foo()
...
end
-- Function 'foo' is deprecated, use 'bar' instead. foo suffers from performance issues
foo()
```
* `lua_cpcall` C API function has been restored both for compatibility
with Lua 5.1 and as a safe way to enter protected call environment to
work with Luau C API functions that may error
Instead of
```
if (!lua_checkstack(L, 2))
return -1;
lua_pushcfunction(L, test, nullptr);
lua_pushlightuserdata(L, context);
int status = lua_pcall(L, 1, 0, 0);
```
you can simply do
```
int status = lua_cpcall(L, test, context);
```
* In Luau CLI, required module return values can now have any type
## New Type Solver
- Additional improvements on type refinements used with external types
should fix some reported false positive errors where types refined to
`never`
- Fixed an issue in recursive refinement types in a form of `t1 where t1
= refine<t1, _>` getting 'stuck'
- Fixed an issue in subtyping of generic functions, it is now possible
to assign `<T>(T, (T) -> T) -> T` to `(number, <X>(X) -> X) -> number`
- Fixed an ICE caused by recursive types (Fixes#1686)
- Added additional iteration and recursion limits to stop the type
solver before system resources are used up
## Internal Contributors
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Annie Tang <annietang@roblox.com>
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Ilya Rezvov <irezvov@roblox.com>
Co-authored-by: Sora Kanosue <skanosue@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
## General
- Support AstStatDeclareGlobal output as a source string (via
@karl-police in #1889)
- Luau heap dump correctly reports the size of a string, now including
overhead for the string type
- Prevent yields from Luau `xpcall` error handling function.
## Analysis
- Avoid exponential blowup when normalizing union of normalized free
variables.
- Fix type pack-related bugs that caused infinite recursion when:
- A generic type pack was bound to itself during subtyping.
- In type pack flattening, when that same generic type pack was now
being bound another generic type pack which contained it.
- Properly simplify `any & (*error-type* | string)` to `*error-type* |
*error-type* | string` instead of hanging due to creating a huge union
type.
---
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Sora Kanosue <skanosue@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: Menarul Alam <malam@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Another week, another release!
## Analysis
- Hide errors in all solver modes (not just strict mode) if the only
error is that type inference failed to complete.
- Make various analysis components solver-agnostic (`setType`, `visit`,
`Scope` methods).
- Fix an issue where type inference may fail to complete when assigning
a table's member to the table itself.
- Fix a bug when accessing a table member on a local after the local is
assigned to in an if-else block, loop, or other similar language
construct.
- Fixes#1914.
- Fix type-checking of if-then-else expressions.
- Fixes#1815.
---
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
We're back on track after the long weekend!
## General
- `clang-format`ed new code. Keep your code tidy!
- Disable some Luau tests that are broken currently.
- Enable fragment autocomplete to do tagged union completion for modules
typechecked in the old solver.
## New Type Solver
- Fix false positives on generic type packs in non-strict mode.
- Update type signature of `setmetatable` to be `<T, MT>(T, MT) ->
setmetatable<T, MT>`.
- Make local type aliases available in type functions. For example:
```
type Foo = number
type Array<T> = {T}
type function Bar(t)
return types.unionof(Foo, Array(t))
end
```
## VM/Runtime
- Make sure `lua_unref` doesn't accept refs which did not exist in the
table.
---
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Sora Kanosue <skanosue@roblox.com>
Co-authored-by: Talha Pathan <tpathan@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: Menarul Alam <malam@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
# General
* Expose an optional `get_alias` API as an alternative to `get_config`
in Luau.Require and Luau.RequireNavigator.
* Improve the Luau CLI's virtual filesystem implementation to fix bugs
related to `init.luau`. Fixes
https://github.com/luau-lang/luau/issues/1816
# New Type Solver
* Avoid double reporting errors when erroneous arguments are provided to
type functions.
* Fix some instances of unresovable cyclic type functions in loops by
only considering the first loop cycles. This results in some type
inference inaccuracies when the type of a variable in loop through
multiple iterations. Fixes
https://github.com/luau-lang/luau/issues/1413.
* Better generalize free types that have meaningful lower and upper
bounds, especially for table indexers.
* Report more specific errors when assigning or returning table literal
types, instead of citing the *entire* table type.
* Inference for functions with generic type packs is greatly improved.
* Fix some internal compiler exceptions when using type-stating
functions like `table.freeze` in `if _ then _ else _` expressions and
short circuiting binary operations.
* More consistently simplify unions of primitive types, especially in
array-like and dictionary-like tables.
* Fix a crash when type checking an erroneous type alias containing
`typeof` with a type assertion expression, as in:
```
type MyTable = {}
-- This will error at type checking time as it's a duplicate
type MyTable = typeof(setmetatable(SomeTable :: {}, SomeMetaTable));
```
* Fix a crash when inferring the type of an index expression where the
indexee is invalid (e.g. `nil`).
# Runtime
* Avoid throwing an exception from `luau_load` if we run out of memory.
* Type functions are no longer compiled and included in bytecode. Fixes
#1817.
* Fix some instances of Luau C API functions reading invalid debug
information (generally when the first or last instruction of a block was
being inspected). Fixes#1369.
* Avoid potential signed integer overflow when doing bounds checks on
tables.
* Support 16 byte aligned userdata objects when system allocation
alignment is also 16 bytes.
* Fix memory leaks in `Luau.Require` when using VM build with no
exceptions. Fixes#1827.
---------
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: James McNellis <jmcnellis@roblox.com>
Co-authored-by: Sora Kanosue <skanosue@roblox.com>
Co-authored-by: Talha Pathan <tpathan@roblox.com>
Co-authored-by: Varun Saini <vsaini@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Hello all! Another week, another Luau release!
# Change to `lua_setuserdatametatable`
This release fixes#1710: `lua_setuserdatametatable` is being changed so
that it _only_ operates on the top of the stack: the `idx` parameter is
being removed. Prior to this, `lua_setuserdatametable` would set the
metatable of the value in the stack at `idx`, but _always_ pop the top
of the stack. The old behavior is available in this release as
`lua_setuserdatametatable_DEPRECATED`.
# General
This release exposes a generalized implementation of require-by-string's
autocomplete logic. `FileResolver` can now be optionally constructed
with a `RequireSuggester`, which provides an interface for converting a
given module to a `RequireNode`. Consumers of this new API implement a
`RequireNode` to define how modules are represented in their embedded
context, and the new API manages the logic specific to
require-by-string, including providing suggestions for require aliases.
This enhancement moves toward integrating require-by-string's semantics
into the language itself, rather than merely providing a specification
for community members to implement themselves.
# New Type Solver
* Fixed a source of potential `Luau::follow detected a Type cycle`
internal compiler exceptions when assigning a global to itself.
* Fixed an issue whereby `*no-refine*` (a type which should not be
visible at the end of type checking) was not being properly elided,
causing inference of class-like tables to become unreadable / induce
crashes in autocomplete.
* Fixed a case of incomplete constraint solving when performing basic
math in a loop
# Fragment Autocomplete
* Fixed several crashes related to not properly filling in scope
information for the fragments
* Fixed a source of memory corruption by isolating the return type of a
fragment when it is type checked.
* Improved performance by opting not to clone persistent types for the
fragment (e.g.: built in types)
# Internal Contributors
Co-authored-by: Andy Friesen <afriesen@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: 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>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Co-authored-by: Ariel Weiss <aaronweiss@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
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
## What's Changed
### General
- Allow types of tables to diverge after using `table.clone` (fixes
#1617).
- Allow 2-argument vector.create in Luau.
- Fix a crash when suggesting autocomplete after encountering parsing
errors.
- Add lua_tolstringatom C API which returns the string length (whether
or not the atom exists) and which extends the existing lua_tostringatom
function the same way lua_tolstring/lua_tostring do.
- Luau now retains the DFGs of typechecked modules.
### Magic Functions Migration Note
We've made a change to the API used to define magic functions.
Previously, we had a set of function pointers on each `FunctionType`
that would be invoked by the type inference engine at the correct point.
The problem we'd run into is that they were all `std::function`s, we'd
grown quite a few of them, and Luau allocates tens of thousands of types
as it performs type inference. This adds up to a large amount of memory
for data that isn't used by 99% of types.
To slim things down a bit, we've replaced all of those `std::function`s
with a single `shared_ptr` to a new interface called `MagicFunction`.
This slims down the memory footprint of each type by about 50 bytes.
The virtual methods of `MagicFunction` have roughly 1:1 correspondence
with the old interface, so updating things should not be too difficult:
* `FunctionType::magicFunction` is now `MagicFunction::handleOldSolver`
* `FunctionType::dcrMagicFunction` is now `MagicFunction::infer`
* `FunctionType::dcrMagicRefinement` is now `MagicFunction::refine`
* `FunctionType::dcrMagicTypeCheck` is now `MagicFunction::typeCheck`
**Full Changelog**:
https://github.com/luau-lang/luau/compare/0.657...0.658
---
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Aviral Goel <agoel@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>
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
## 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>
### What's New?
* Fragment Autocomplete: a new API allows for type checking a small
fragment of code against an existing file, significantly speeding up
autocomplete performance in large files.
### New Solver
* E-Graphs have landed: this is an ongoing approach to make the new type
solver simplify types in a more consistent and principled manner, based
on similar work (see: https://egraphs-good.github.io/).
* Adds support for exporting / local user type functions (previously
they were always exported).
* Fixes a set of bugs in which the new solver will fail to complete
inference for simple expressions with just literals and operators.
### General Updates
* Requiring a path with a ".lua" or ".luau" extension will now have a
bespoke error suggesting to remove said extension.
* Fixes a bug in which whether two `Luau::Symbol`s are equal depends on
whether the new solver is enabled.
---
Internal Contributors:
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: David Cope <dcope@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>
* 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
* Implemented parsing logic for attributes
* Added `lua_setuserdatametatable` and `lua_getuserdatametatable` C API
methods for a faster userdata metatable fetch compared to
`luaL_getmetatable`. Note that metatable reference has to still be
pinned in memory!
### New Solver
* Further improvement to the assignment inference logic
* Fix many bugs surrounding constraint dispatch order
### Native Codegen
* Add IR lowering hooks for custom host userdata types
* Add IR to create new tagged userdata objects
* Remove outdated NativeState
---
### 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: Aviral Goel <agoel@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
This change adds support for tagged lightuserdata and optional custom
typenames for lightuserdata.
Background: Lightuserdata is an efficient representation for many kinds
of unmanaged handles and resources in a game engine. However, currently
the VM only supports one kind of lightuserdata, which makes it
problematic in practice. For example, it's not possible to distinguish
between different kinds of lightuserdata in Lua bindings, which can lead
to unsafe practices and even crashes when a wrong kind of lightuserdata
is passed to a binding function. Tagged lightuserdata work similarly to
tagged userdata, i.e. they allow checking the tag quickly using
lua_tolightuserdatatagged (or lua_lightuserdatatag).
The tag is stored in the 'extra' field of TValue so it will add no cost
to the (untagged) lightuserdata type.
Alternatives would be to use full userdata values or use bitpacking to
embed type information into lightuserdata on application level.
Unfortunately these options are not that great in practice: full
userdata have major performance implications and bitpacking fails in
cases where full 64 bits are already used (e.g. pointers or 64-bit
hashes).
Lightuserdata names are not strictly necessary but they are rather
convenient when debugging Lua code. More precise error messages and
tostring returning more specific typename are useful to have in practice
(e.g. "resource" or "entity" instead of the more generic "userdata").
Impl note: I did not add support for renaming tags in
lua_setlightuserdataname as I'm not sure if it's possible to free fixed
strings. If it's simple enough, maybe we should allow renaming (although
I can't think of a specific need for it)?
---------
Co-authored-by: Petri Häkkinen <petrih@rmd.remedy.fi>
### What's Changed
- Improve readability of unions and intersections by limiting the number
of elements of those types that can be presented on a single line (gated
under `FFlag::LuauToStringSimpleCompositeTypesSingleLine`)
- Adds a new option to the compiler `--record-stats` to record and
output compilation statistics
- `if...then...else` expressions are now optimized into `AND/OR` form
when possible.
### VM
- Add a new `buffer` type to Luau based on the [buffer
RFC](https://github.com/Roblox/luau/pull/739) and additional C API
functions to work with it; this release does not include the library.
- Internal C API to work with string buffers has been updated to align
with Lua version more closely
### Native Codegen
- Added support for new X64 instruction (rev) and new A64 instruction
(bswap) in the assembler
- Simplified the way numerical loop condition is translated to IR
### New Type Solver
- Operator inference now handled by type families
- Created a new system called `Type Paths` to explain why subtyping
tests fail in order to improve the quality of error messages.
- Systematic changes to implement Data Flow analysis in the new solver
(`Breadcrumb` removed and replaced with `RefinementKey`)
---
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: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
---------
Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
- Updated Roblox copyright to 2023
- Floor division operator `//` (implements #832)
- Autocomplete now shows `end` within `do` blocks
- Restore BraceType when using `Lexer::lookahead` (fixes#1019)
# New typechecker
- Subtyping tests between metatables and tables
- Subtyping tests between string singletons and tables
- Subtyping tests for class types
# Native codegen
- Fixed macOS test failure (wrong spill restore offset)
- Fixed clobbering of non-volatile xmm registers on Windows
- Fixed wrong storage location of SSA reg spills
- Implemented A64 support for add/sub extended
- Eliminated zextReg from A64 lowering
- Remove identical table slot lookups
- Propagate values from predecessor into the linear block
- Disabled reuse slot optimization
- Keep `LuaNode::val` check for nil when optimizing `CHECK_SLOT_MATCH`
- Implemented IR translation of `table.insert` builtin
- Fixed mmap error handling on macOS/Linux
# Tooling
- Used `|` as a column separator instead of `+` in `bench.py`
- Added a `table.sort` micro-benchmark
- Switched `libprotobuf-mutator` to a less problematic version
* Fixed exported types not being suggested in autocomplete
* `T...` is now convertible to `...any` (Fixes
https://github.com/Roblox/luau/issues/767)
* Fixed issue with `T?` not being convertible to `T | T` or `T?`
(sometimes when internal pointer identity is different)
* Fixed potential crash in missing table key error suggestion to use a
similar existing key
* `lua_topointer` now returns a pointer for strings
C++ API Changes:
* `prepareModuleScope` callback has moved from TypeChecker to Frontend
* For LSPs, AstQuery functions (and `isWithinComment`) can be used
without full Frontend data
A lot of changes in our two experimental components as well.
In our work on the new type-solver, the following issues were fixed:
* Fixed table union and intersection indexing
* Correct custom type environments are now used
* Fixed issue with values of `free & number` type not accepted in
numeric operations
And these are the changes in native code generation (JIT):
* arm64 lowering is almost complete with support for 99% of IR commands
and all fastcalls
* Fixed x64 assembly encoding for extended byte registers
* More external x64 calls are aware of register allocator
* `math.min`/`math.max` with more than 2 arguments are now lowered to IR
as well
* Fixed correctness issues with `math` library calls with multiple
results in variadic context and with x64 register conflicts
* x64 register allocator learnt to restore values from VM memory instead
of always using stack spills
* x64 exception unwind information now supports multiple functions and
fixes function start offset in Dwarf2 info
Some userdata objects may need to support manual destruction in addition
to automatic GC. For example, files, threads, GPU resources and objects
with large external allocations.
With Lua, a finalizer can be _generically_ called by invoking the __gc
metamethod manually, but this is currently not possible with tagged
userdata in Luau because it's not possible to query the destructor
associated with an userdata. While it is possible to workaround this by
duplicating the destructor table locally on client side (*), it's more
convenient to deduplicate the data and get the destructor using the API
instead.
(*) Note: a separate destructor table for each VM may be required if the
VMs use different set of tags.
Implementation notes:
1. I first considered adding a typedef for lua_Destructor but
unfortunately there are two kinds of destructors, one with and one
without the lua_State* argument, so I decided against it at this point.
Maybe it should be added later if the destructor API is unified (by
dropping the Lua state pointer argument?).
2. For some reason the conformance test produced warning "qualifier
applied to function type has no meaning; ignored" on VS2017 (possibly
because the test framework does not like function pointers for some
reason?). I silenced this by pulling out the test expressions from those
CHECKs.
`lua_getupvalue()` and `lua_setupvalue()` don't behave as expected when
working with Lua closure whose `Proto` has no debug info. The code
currently uses `sizeupvalues` to do bounds checking of upvalue indices,
but that's the size of the upvalue _names_ array. It will always be `0`
if the `Proto` doesn't have debug info.
This uses `nups` instead, and just returns `""` as the upvalue name if
we don't have one, same as for C closures.
Co-authored-by: Harold Cindy <HaroldCindy@users.noreply.github.com>
- Type aliases can no longer override primitive types; attempts to do
that will result in a type error
- Fix misleading type error messages for mismatches in expression list
length during assignment
- Fix incorrect type name display in certain cases
- setmetatable/getmetatable are now ~2x faster
- tools/perfstat.py can be used to display statistics about profiles
captured via --profile switch
To my understanding lua_cleartable does not need GC barriers because
it's only removing elements and not modifying the stack. But I'm not a
GC expert so please correct if I'm wrong.
resolves#672
Co-authored-by: Petri Häkkinen <petrih@rmd.remedy.fi>
- Improve type error messages for argument count mismatch in certain
cases
- Fix type checking variadic returns when the type is incompatible which
type checked in certain cases
- Reduce size of upvalue objects by 8 bytes on 64-bit platforms
- Reduce I$ footprint of interpreter by 1.5KB
- Reduce GC pause during atomic stage for programs with a lot of threads
- Remove support for bytecode v2
Luau currently has the following functions in the C API for dealing with
tables without invoking metamethods:
lua_rawgetfield
lua_rawget
lua_rawgeti
lua_rawset
lua_rawseti
This change adds the missing function lua_rawsetfield for consistency
and because it's more efficient to use it in place of plain lua_rawset
which requires pushing the key and value separately.
Co-authored-by: Petri Häkkinen <petrih@rmd.remedy.fi>
- Remove type definitions of
`utf8.nfcnormalize`/`nfdnormalize`/`graphemes` that aren't supported by
standalone Luau library
- Add `lua_costatus` to retrieve extended thread status (similar to
`coroutine.status`)
- Improve GC sweeping performance (2-10% improvement on allocation-heavy
benchmarks)
- Fix DeprecatedGlobal warning text in cases when the global is deprecated without a suggested alternative
- Fix an off-by-one error in type error text for incorrect use of string.format
- Reduce stack consumption further during parsing, hopefully eliminating stack overflows during parsing/compilation for good
- Mark interpolated string support as experimental (requires --fflags=LuauInterpolatedStringBaseSupport to enable)
- Simplify garbage collection treatment of upvalues, reducing cache misses during sweeping stage and reducing the cost of upvalue assignment (SETUPVAL); supersedes #643
- Simplify garbage collection treatment of sleeping threads
- Simplify sweeping of alive threads, reducing cache misses during sweeping stage
- Simplify management of string buffers, removing redundant linked list operations
- Fix autocomplete not suggesting globals defined after the cursor (fixes#622)
- Improve type checker stability
- Reduce parser C stack consumption which fixes some stack overflow crashes on deeply nested sources
- Improve performance of bit32.extract/replace when width is implied (~3% faster chess)
- Improve performance of bit32.extract when field/width are constants (~10% faster base64)
- Heap dump now annotates thread stacks with local variable/function names
In case a large userdata size is passed to lua_newuserdatadtor it might overflow the size resulting in luaU_newudata actually allocating the object without a memory error. This will then result in overwriting part of the metatable pointer of the userdata.
This PR fixes this issue by checking for the overflow and in such cases pass a size value which will cause a memory error in luaU_newudata.
* Fix free Luau type being fully overwritten by 'any' and causing UAF
* Fix lua_clonefunction implementation replacing top instead of pushing
* Falsey values other than false can now narrow refinements
* Fix lua_getmetatable, lua_getfenv not waking thread up
* FIx a case where lua_objlen could push a new string without thread wakeup or GC
* Moved Luau math and bit32 definitions to definition file
* Improve Luau parse recovery of incorrect return type token
* Run clang-format
* Contains a preliminary implementation of deferred constraint resolution
* Reduce stack usage by some recursive functions
* Fix a bug when smartCloning a BoundTypeVar
* Remove some GC related flags from VM
* Adds a currently unused x86-64 assembler as a prerequisite for possible future JIT compilation
* Fix a bug in table iteration (closes Possible table iteration bug #504)
* Improved warning method when function is used as a type
* Fix a bug with unsandboxed iteration with pairs()
* Type of coroutine.status() is now a union of value types
* Bytecode output for tests/debugging now has labels
* Improvements to loop unrolling cost estimation
* Report errors when the key obviously doesn't exist in the table
- Improve refinement support for unions, in particular it's now possible to implement tagged unions as a union of tables where individual branches use a string literal type for one of the fields.
- Fix `string.split` type information
- Optimize `select(_, ...)` to run in constant time (~2.7x faster on VariadicSelect benchmark)
- Improve debug line information for multi-line assignments
- Improve compilation of table literals when table keys are constant expressions/variables
- Use forward GC barrier for `setmetatable` which slightly accelerates GC progress
- Rework transaction log used for type checking which should result in more robust type checking internals with fewer bugs
- Reduce the amount of memory consumed by type checker on large module graphs
- Type checker now errors on attempts to change the type of imported module fields
- The return type of newproxy is now any (fixes#296)
- Implement new number printing algorithm (Schubfach) which makes tostring() produce precise (round-trippable) and short decimal output up to 10x faster
- Fix lua_Debug::linedefined to point to the line with the function definition instead of the first statement (fixes#265)
- Fix minor bugs in Tab completion in Repl
- Repl now saves/restores command history in ~/.luau_history
