This week we only have updates to new type solver and JIT. Both projects
are still in the process of being built out. Neither are ready for
general use yet.
In the new solver, we fixed issues with recursive type aliases.
Duplicated type parameters are once again reported, exported types are
being recorder and function argument names are placed inside function
types.
We also made improvements to restore parts of bidirectional type
tracking.
On native code generation side, namecall instruction lowering was fixed,
we fixed inconsistencies in IR command definitions and added utility
function to help with constant folding.
* Fix a bug where reading a property from an unsealed table caused
inference to improperly infer the existence of that property.
* Fix#827
We have also made a lot of progress on the new solver and the JIT. Both
projects are still in the process of being built out. Neither are ready
for general use yet.
We are mostly working to tighten up how the new solver handles
refinements and updates to unsealed tables to bring it up to the same
level as the old solver.
---------
Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
* Fixed rare use-after-free in analysis during table unification
A lot of work these past months went into two new Luau components:
* A near full rewrite of the typechecker using a new deferred constraint
resolution system
* Native code generation for AoT/JiT compilation of VM bytecode into x64
(avx)/arm64 instructions
Both of these components are far from finished and we don't provide
documentation on building and using them at this point.
However, curious community members expressed interest in learning about
changes that go into these components each week, so we are now listing
them here in the 'sync' pull request descriptions.
---
New typechecker can be enabled by setting
DebugLuauDeferredConstraintResolution flag to 'true'.
It is considered unstable right now, so try it at your own risk.
Even though it already provides better type inference than the current
one in some cases, our main goal right now is to reach feature parity
with current typechecker.
Features which improve over the capabilities of the current typechecker
are marked as '(NEW)'.
Changes to new typechecker:
* Regular for loop index and parameters are now typechecked
* Invalid type annotations on local variables are ignored to improve
autocomplete
* Fixed missing autocomplete type suggestions for function arguments
* Type reduction is now performed to produce simpler types to be
presented to the user (error messages, custom LSPs)
* Internally, complex types like '((number | string) & ~(false?)) |
string' can be produced, which is just 'string | number' when simplified
* Fixed spots where support for unknown and never types was missing
* (NEW) Length operator '#' is now valid to use on top table type, this
type comes up when doing typeof(x) == "table" guards and isn't available
in current typechecker
---
Changes to native code generation:
* Additional math library fast calls are now lowered to x64: math.ldexp,
math.round, math.frexp, math.modf, math.sign and math.clamp
* For autocomplete, additional information is included in Scope for type
alias name locations and names of imported modules
* Improved autocomplete suggestions in 'for' and 'while' loop headers
* String match functions return types are now optional strings and
numbers because match is not guaranteed at runtime
* Fixed build issue on gcc 11 and up (Fixes
https://github.com/Roblox/luau/issues/806)
* Fix autocompletion of if-then-else expressions
* Fix a potential crash surrounding improper use of `%*` in a string
format specifier
* All Python scripts now invoke Python via `python3` rather than
`python`.
* Improved error handling for string interpolation with too many
arguments.
Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
Having the location where the table type is defined is useful for
tracking other info such as documentation comments, or pointing back
through "Go To Definition" functionality etc.
This adds in the required info
Closes#718
We pass an extra `contents` parameter to the string callback function to
provide contextual information for autocomplete.
Because we support both string literals and simple interpolated strings,
we pass it through as a `std::string` value.
This is a breaking change
* Fixed garbage data in module scopes when type graph is not retained
* LOP_MOVE with the same source and target registers is no longer
generated (Fixes https://github.com/Roblox/luau/issues/793)
* Fixed unions of `nil` types displaying as `?`
* Internal normalization now handles class types which can make
previously failing (incorrectly) sub-typing checks to succeed
* The AST JSON encoder will now stringify infinity and NaN according to the JSON5 spec using the tokens `Infinity`, `-Infinity`, and `NaN`.
* Improve autocompletion of table keys if the type of that key is a union of string singletons.
* Type mismatch errors now mention if unification failed in covariant or
invariant context, to explain why sometimes derived class can't be
converted to base class or why `T` can't be converted into `T?` and so
on
* Class type indexing is no longer an error in non-strict mode (still an
error in strict mode)
* Fixed cyclic type packs not being displayed in the type
* Added an error when unrelated types are compared with `==`/`~=`
* Fixed false positive errors involving sub-type tests an `never` type
* Fixed miscompilation of multiple assignment statements (Fixes
https://github.com/Roblox/luau/issues/754)
* Type inference stability improvements
Currently, the metatable of a class type var is not correctly checked to
see if it is callable (i.e. has a `__call` metatable).
We resolve this issue by checking the metatable in `checkCallOverload`
Fixes#756
Co-authored-by: vegorov-rbx <75688451+vegorov-rbx@users.noreply.github.com>
Closes#631
Performs a "two pass" approach, where we first call `prototype` on the
class definition.
The prototype phase checks for errors and creates a base CTV for the
class, which other types can then reference.
The second `check` phase fills it out with all the defined
properties/methods
Co-authored-by: vegorov-rbx <75688451+vegorov-rbx@users.noreply.github.com>
String interpolation autocomplete was not working and was just using
default autocomplete. This fixes it so that inside a string it is
treated as normal, and inside an expression it suggests expression level
autocomplete.
Also fixes the range, which was previously just the first lexeme.
* Type inference of `a and b` and `a or b` has been improved (Fixes
https://github.com/Roblox/luau/issues/730)
* Improved error message when `for ... in x` loop iterates over a value
that could be 'nil'
* Return type of `next` not includes 'nil' (Fixes
https://github.com/Roblox/luau/issues/706)
* Improved type inference of `string` type
* Luau library table type names are now reported as `typeof(string)`/etc
instead of just `string` which was misleading
* Added parsing error when optional type alias type parameter wasn't
provided after `=` token
* Improved tagged union type refinement in conditional expressions, type
in `else` branch should no longer include previously handled union
options
* Reduce the stack utilization of type checking.
* Improve the error message that's reported when a delimiting comma is
missing from a table literal. eg
```lua
local t = {
first = 1
second = 2
}```
* https://github.com/Roblox/luau/pull/719
* Improved `Failed to unify type packs` error message to be reported as
`Type pack 'X' could not be converted into 'Y'`
* https://github.com/Roblox/luau/pull/722
* 1% reduction in executed instruction count by removing a check in fast
call dispatch
* Additional fixes to reported error location of OOM errors in VM
* Improve `math.sqrt`, `math.floor` and `math.ceil` performance on
additional compilers and platforms (1-2% geomean improvement including
8-9% on math-cordic)
* All thrown exceptions by Luau analysis are derived from
`Luau::InternalCompilerError`
* When a call site has fewer arguments than required, error now reports
the location of the function name instead of the argument to the
function
* https://github.com/Roblox/luau/pull/724
* Fixed https://github.com/Roblox/luau/issues/725
Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Right now `getDocumentationSymbol` on an overloaded class method or
table prop just gives the prop name, not prepended with `/overload/ +
toString(overload)`.
This causes the incorrect symbol to be used for `table.insert`,
`BrickColor.new`, `Color3.new` etc. (present in
https://raw.githubusercontent.com/MaximumADHD/Roblox-Client-Tracker/roblox/api-docs/en-us.json)
Co-authored-by: vegorov-rbx <75688451+vegorov-rbx@users.noreply.github.com>
* Support `["prop"]` syntax on class definitions in definition files.
(#704)
* Improve type checking performance for complex overloaded functions
* Fix rare cases of incorrect stack traces for out of memory errors at
runtime
Name the parameters used in `math` lib
This is mainly done to highlight the particular confusion for
`math.atan2`, where `y` comes before `x`, but this might not be
immediately obvious.
And then I added the rest of the names for consistency.
Note: I didn't add names to `math.random` as it's currently typed as
`(number?, number?) -> number`. Naming it `min` and `max` is technically
incorrect for the 1 argument version.
Maybe it should be typed as an intersection instead?
`Frontend.markDirty()` does not correctly mark reverse dependencies that
are not immediate as dirty.
This is because it would keep adding the reverse deps of `name` into the
queue to mark as dirty, instead of the reverse deps of `next`
* Reoptimized math.min/max/bit32 builtins assuming at least 2 arguments are used (1-2% lift on some benchmarks)
* Type errors that mention function types no longer have redundant parenthesis around return type
* Luau REPL now supports --compile=remarks which displays the source code with optimization remarks embedded as comments
* Builtin calls are slightly faster when called with 1-2 arguments (~1% improvement in some benchmarks)
- Fix rare type checking bugs with invalid generic types escaping the
module scope
- Fix type checking of variadic type packs in certain cases
- Implement type normalization, which resolves a large set of various
issues with unions/intersections in type checker
- Improve parse errors for trailing commas in function calls and type
lists
- Reduce profiling skew when using --profile with very high frequencies
- Improve performance of `lua_getinfo` (`debug.info`, `debug.traceback`
and profiling overhead are now 20% faster/smaller)
- Improve performance of polymorphic comparisons (1-2% lift on some
benchmarks)
- Improve performance of closure creation (1-2% lift on some benchmarks)
- Improve string comparison performance (4% lift on string sorting)
- 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
- 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
- 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)
- Improve ComparisonPrecedence lint suggestions for three-way comparisons (X < Y < Z)
- Improve type checking stability
- Improve location information for errors when parsing invalid type annotations
- Compiler now generates bytecode version 3 in all configurations
- Improve performance of comparisons against numeric constants on AArch64
- 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
Implements the string interpolation RFC (#165).
Adds the string interpolation as per the RFC.
```lua
local name = "world"
print(`Hello {name}!`) -- Hello world!
```
Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Co-authored-by: Alexander McCord <11488393+alexmccord@users.noreply.github.com>
Fixes a bug where the environment scope is not passed to the autocomplete typechecker, so environment-related types are not provided.
This caused an issue where `getModuleEnvironment` returns `typeChecker.globalScope` when there is no environment. We pass this through to `typeCheckerForAutocomplete.check()` then environmentscope is no longer nullopt and it will use `typeChecker.globalScope` instead of falling back to `typeCheckerForAutocomplete.globalScope`.
This is solved by passing `forAutocomplete` to `getModuleEnvironment` so it falls back to the autocomplete global scope if none found.
- 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
Closes#599
Not sure if these context definitions are distinct enough, but they work for my use cases.
I repurposed (a majority of) the existing unit tests for this, but if it should live in separate test cases let me know
---
* Add autocomplete context to result
* Update tests
* Remove comments
* Fix expression context issues
* 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
* Respect useLineBreaks for union/intersect toString
* Apply suggestions from code review
Co-authored-by: Andy Friesen <andy.friesen@gmail.com>
Co-authored-by: Andy Friesen <andy.friesen@gmail.com>
Adds an option to hide the `self: type` argument as the first argument in the string representation of a named function type var if the ftv hasSelf.
Also added in a test for the original output (i.e., if the option was disabled)
I didn't apply this option in the normal `Luau::toString()` function, just the `Luau::toStringNamedFunction()` one (for my usecase, that is enough + I felt like a named function would include the method colon `:` to signify self). If this is unintuitive, I can also add it to the general `Luau::toString()` function.
We don't emit type annotations right now for `AstLocal`s in the JSON encoder. This makes it really hard to surface annotations in the Agda implementation. This PR changes it to emit location and type annotations, if present.
- 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
- TableOperations lint now includes a warning for table.create(N, {}) (which is likely a mistake since the table is shared by all entries)
- Type checker now type checks #v when v is a union
- Parser now rejects sources that consists of a single unfinished long comment
- Work around significant MSVC 2022 performance regression, bringing it more or less in line with MSVC 2019
- Compiler now predicts array size for newly allocated tables when the table is filled in a short loop
- Small improvements in compilation throughput (~2% faster)
- Implement paged sweeper for GC which improves sweep throughput 2-3x and reduces memory consumption by 8 bytes per object (once it is stabilized we will see additional 8 bytes per object of savings)
- Improve Repl Tab completion
- Repl now supports -i (interactive mode to run code in context of a script's environment) and -On (to control optimization flags)
- 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
This doesn't contain all changes for 507 yet but we might want to do the
Luau 0.507 release a bit earlier to end the year sooner.
Changes:
- Type ascription (::) now permits casts between related types in both directions, allowing to refine or loosen the type (RFC #56)
- Fix type definition for tonumber to return number? since the input string isn't guaranteed to contain a valid number
- Fix type refinements for field access via []
- Many stability fixes for type checker
- Provide extra information in error messages for type mismatches in more cases
- Improve performance of type checking for large unions when union members are string literals
- Add coverage reporting support to Repl (--coverage command line argument) and lua_getcoverage C API
- Work around code signing issues during Makefile builds on macOS
- Improve performance of truthiness checks in some cases, particularly on Apple M1, resulting in 10-25% perf gains on qsort benchmark depending on the CPU/compiler
- Fix support for little-endian systems; IBM s390x here we go!
- Fix some cases where type checking would overflow the native stack
- Improve autocomplete behavior when assigning a partially written function call (not currently exposed through command line tools)
- Improve autocomplete type inference feedback for some expressions where previously the type would not be known
- Improve quantification performance during type checking for large types
- Improve type checking for table literals when the expected type of the table is known because of a type annotation
- Fix type checking errors in cases where required module has errors in the resulting type
- Fix debug line information for multi-line chained call sequences (Add function name information for "attempt to call a nil value" #255)
- lua_newuserdata now takes 2 arguments to match Lua/LuaJIT APIs better; lua_newuserdatatagged should be used if the third argument was non-0.
- lua_ref can no longer be used with LUA_REGISTRYINDEX to prevent mistakes when migrating Lua FFI (Inconsistency with lua_ref #247)
- Fix assertions and possible crashes when executing script code indirectly via metatable dispatch from lua_equal/lua_lessthan/lua_getfield/etc. (Hitting a crash in an assert after lua_equal is called. #259)
- Fix flamegraph scripts to run under Python 2
- Improve error recovery during type checking
- Initial (not fully complete) implementation for singleton types (RFC RFC: Singleton types #37)
- Implement a C-friendly interface for compiler (luacode.h)
- Remove C++ features from lua.h (removed default arguments from luau_load and lua_pushcfunction)
- Fix lua_breakpoint behavior when enabled=false
- Implement coroutine.close (RFC RFC: coroutine.close #88)
Note, this introduces small breaking changes in lua.h:
- luau_load env argument is now required, pass an extra 0
- lua_pushcfunction now must be called with 3 arguments; if you were calling it with 2 arguments, pass an extra NULL; if you were calling it with 4, use lua_pushcclosure.
These changes are necessary to make sure lua.h can be used from pure C - the future release will make it possible by adding an option to luaconf.h to change function name mangling to be C-compatible. We don't anticipate breaking the FFI interface in the future, but this change was necessary to restore C compatibility.
Closes#121Fixes#213
We keep getting compat reports for warnings in various compiler
versions. While we can keep merging PRs to resolve these warnings, it
would be nice if the users of other compilers or compiler versions weren't
blocked on us fixing this.
As such, this change disables Werror by default and only enables it when
requested, which happens in CI in test builds.
- Type mismatch errors now show detailed information for compound types, highlighting the mismatching component
- Fix string.pack bug on ARM when packing negative numbers using unsigned formats
- Implement bit32.countlz/countrz (RFC RFC: bit32.countlz/countrz #89)
- Minor compiler throughput optimization (~2% faster compilation)
- Improve transpiler behavior for edge cases and better test coverage (not exposed through CLI at the moment)
- Improve error recovery when parsing invalid assignments
- Build fixes for fuzzing targets
- A series of major optimizations to type checking performance on complex
programs/types (up to two orders of magnitude speedup for programs
involving huge tagged unions)
- Fix a few issues encountered by UBSAN (and maybe fix s390x builds)
- Fix gcc-11 test builds
- Fix a rare corner case where luau_load wouldn't wake inactive threads
which could result in a use-after-free due to GC
- Fix CLI crash when error object that's not a string escapes to top level
- Fix Makefile suffixes on macOS
Co-authored-by: Rodactor <rodactor@roblox.com>
Changes:
- Support for time tracing for analysis/compiler (not currently exposed
through CLI)
- Support for type pack arguments in type aliases (#83)
- Basic support for require(path) in luau-analyze
- Add a lint warning for table.move with 0 index as part of
TableOperation lint
- Remove last STL dependency from Luau.VM
- Minor VS2022 performance tuning
Co-authored-by: Rodactor <rodactor@roblox.com>
