Highlights of the release

Error when reading class file with unknown newer jdk version #18618
Add support for xsbti.compile.CompileProgress #18739
Add support for @deprecatedInheritance #19082
Bump JLine 3.19.0 -> 3.24.1 & sbt 1.9.7 -> 1.9.9 #19744
Repl - method signatures in autocomplete #19917
Upgrade Scala 2 to 2.13.14 (was 2.13.12) #20902

Notable changes

Backport of #20463 corrects generic signatures emitted in the JVM bytecode for value classes and aligns it with Scala 2.13 semantics. The previously generated signatures for value classes were invalid - they contained underlying value class type instead of boxed type. This change would lead to MiMa errors when signature checks are enabled and could lead to issues when trying to refer to value class methods using reflection API. It would not affect the normal usage of value classes in Scala code compiled with the previous version of the compiler.

Other changes and fixes

Annotations

Attempt implicit search for old style implicit parameters in Application matchArgs #19737

Artifacts

Add versionLine marker to pom.xml #19986
Avoid duplications of properties in pom.xml #20020

Backend

Parallelise JVM backend - Scala 2 port #15392
Fix Closure span assignment in makeClosure #15841
Count size of parameters for platform limit check #18464
Opt: Get rid of the LiftTry phase; instead handle things in the back-end. #18619
Update asm to 9.6 #18712
Don't emit line number for synthetic unit value #18717
Avoid too eager transform of $outer for lhs & accessor rhs #18949
Make more anonymous functions static #19251
Fix deadlock in initialization of CoreBTypes using Lazy container #19298
Fix(#17255): cannot find Scala companion module from Java #19773
Change isStatic to isStaticOwner in hasLocalInstantiation #19803
Emit switch bytecode when matching unions of a switchable type #20411
Fix EnclosingMethod for lifted anonfun #20558
Fix deterministically adding additional interfaces #20593

Coverage

Correctly prettify names in coverage info #18542
Port coverage filter options for packages and files #19727

Default parameters

Lift all non trivial prefixes for default parameters #19739
Fix default args lookup for given classes #20256
Fix implicit search failure reporting #20261

Derivation

Fix infinite loop in Mirror synthesis of unreducible match type #20133

Desugaring

Make apply proxies work with overloaded ctors #19464
Fix possible crash in Desugar #19567
Add explanation to checkCaseClassInheritanceInvariant error msg #20141

Documentation

[spec] remove implementation details from enum spec #18579
[spec] some fixes to tuples #18582
[spec] Cosmetic changes in the lexical syntax chapter #18608
Spec: Update the list of tokens that can start/end statements. #18611
Update syntax.md #18648
Sync main with language-reference-stable #18718
Completion assert diffs will now show completion source #18890
Fix Export Doc #18952
reference doc: fix incorrect syntax production #19017
State all known limitations of right-associative extension methods #19210
Update explicit-nulls.md #19327
update old issues.scala-lang.org url #19606
Update syntax.md #19670
Clear the not-backported documentation changes queue #19699
remove implementation from asInstanceOf #19753
Port tailrec spec and adjustments to annotations section #19978
Optimize the documentation JS files #20075
Optimize main.js #20093
Improve documentation of implicit conversions #20103
Update Quotes.scala #20174
Supplement structural givens doc #20327
Fix three dead links in spec Types doc chapter #20337
Avoid jpath in example #20775

Erasure

Make eraseInfo work for classes with EmptyScopes #19550
Don't re-balance AndTypes arising from supertypes #20400

Exports

Do not propagate @tailrec to exported methods #19509
Fix retained flags in exports #19636
Add annotations in parameters for exports #20140
Fix isAliasType #20195

GADTs

Only cache base types when gadt state is empty #19562

Implicits

Tweak convertible implicits fix #18727
Run CheckStatic after UncacheGivenAliases #19318
Add tests to verify that crash is fixed elsewhere. Fixes #19328 #19329
Don't search for implicit conversions to NoType #19563
Prefer extensions over conversions for member selection #19717
Adjust owner in Interactive.contextOfPath causing crash in ImplicitSearch #19875
Improve ConstraintHandling of SkolemTypes #20175
Better error diagnostics under -explain-cyclic #20251
Bring back ambiguity filter when we report an implicit not found error #20368
Avoid stacked thisCall contexts #20488

Incremental Compilation

Fix undercompilation upon ctor change #19911
Retain default parameters with export #20167

Inferencing

Adapt toInstantiate in interpolateTypeVars to consider #20399 #20426

Infrastructure

Fix listing release versions for bisect script. #19356
Make tests resilient to exceptions thrown while reporting exceptions #19566
Move CI management from lampepfl/dotty-ci #19697
Switch to Java 17 in the CI #19703
[regression] Publish nightly releases and releases using Java 8 #19722
Bump scalacenter/sbt-dependency-submission from 2 to 3 #20440

Inline

Fix regression: inline match crash when rhs uses private inlined methods #18595
Add structural classes of dynamicApply before inlining #18766
Inline transparent implicit parameters when typing Unapply trees #19646
Specialized retained inline FunctionN apply methods #19801
Restore pre-3.3.2 behavior of inline implicit def #19877
Avoid crash after StopMacroExpansion #19883
Check deprecation of inline methods #19914
Fix by-name parameter in beta-reduction #20096
Type desugared transparent inline def unapply call in the correct mode #20108
Add warning for anonymous inline classes (#16723) #20291
Avoid conversion of Unit type into () term #20295
Fix outerSelect in Inliner #20313
Mark genSJSIR as disabled (rather than non-runnable) when no -scalajs. #20815
Map over refs of ImportTypes in TypeMap #20837

Linting

Implement -Xlint:private-shadow, type-parameter-shadow #17622
Fix false positive in WUnused for renamed path-dependent imports #18468
Fix false positive in WUnused for renamed path-dependent imports (2) #18617
Fix wunused false positive on CanEqual #18641
Fix #20146: attach the original name if there is an import selection for an indent #20163
Use final result type to check selector bound #20989

Match Types

Cover patterns using reflect.TypeTest in isMatchTypeShaped #19923
Do match type reduction atPhaseNoLater than ElimOpaque #20017
Use MirrorSource.reduce result for companionPath #20207

Nullability

Fix #19808: Don't force to compute the owner of a symbol when there is no denotation #19813

Opaque Types

Fix problems with cycle checks #19453
Heal member-select on opaque reference #19730

Parser

Tweak java getlitch not to skip zero #18491
Fix(#18265): crash on extension method without type nor RHS #18743
Simplify parameter handling in Parser #18993
Add support for JEP-409 (sealed classes) + Add javacOpt directive #19080
Parser simple expression error recovery change from null to ??? #19103
Warn when @volatile is used on vals #19462
Fix(#16458): regression in xml syntax parsing #19522
Fix(#16459) xml parse regression #19531
Fix parsing of conditional expressions in parentheses #19985

Pattern Matching

Propagate constant in result of inline match #18455
Fix exhaustivity due to separate TypeVar lambdas #18616
Consider extension methods in Space isSameUnapply #18642
Fix unreachable warning in deeply nested sealed hierarchy #18706
Disable match anaylsis in inlined trees #19190
Warn about unchecked type tests in primitive catch cases #19206
Remove unnecessary and recursive Space decomposition #19216
Fix false unreachable due to opaqueness #19368
Improve recursive decompose prefix fix #19375
Allow constraining a parameter to Nothing #19397
Add a test case, proving i15661 is fixed #19432
Fix #20372: Check pattern match exhaustivity in inlined code #20403

Polyfunctions

Check user defined PolyFunction refinements #18457
Discard poly-functions when trying to resolve overloading #20181

Presentation Compiler

Support completions for extension definition parameter #18331
Fix: Don't collect map, flatMap, withFilter in for-comprehension #18430
Bugfix: Catch exception from the compiler for broken shadowed pickles #18502
Bugfix: highlight for enum type params #18528
Bugfix: No signature help for local methods #18594
Bugfix: add moduleClass imported symbols in IndexedContext #18620
Bugfix: Named args completions with default values #18633
Fix: match completions for type aliases #18667
Bugfix: add multiline comment completion #18703
Bugfix: Backticked named arguments #18704
Bugfix: [metals] Case completions for tuple type #18751
Add missing -Yexplicit-nulls for presentation compiler #18776
Completions should prepend, not replace as it is for Scala 2 #18803
Bugfix: rename end marker #18838
Remove redundant path calculation from Completions in PC #18889
Instantiate Type Vars in completion labels of extension methods #18914
Presentation compiler: Bugfix for semantic tokens and synthetic decorations #18955
Show documentation for value forwarders in completions #19200
Bugfix: Document highlight on class constructors #19209
Improve signature help by more stable position calculation + better named arg support #19214
Bugfix: Completions for extension methods with name conflict #19225
Improvement: Support completions for implicit classes #19314
Chore: Backport changes from Metals #19410
Chore: backport changes from metals #19452
Make order of renames and missing imports deterministic #19468
Make PC more resilient to crashes #19488
Fix goto-def on exported forwarders #19494
Use comma counting for all signature help types #19520
Chore: Backport changes from Metals #19592
Backport pc changes from metals #19617
PC: Replace CC with underlying type in completions #19638
improvement: Replace synthetic decorations with inlay hints #19754
Allow range selection on function parameter to select a parameter list #19777
Weekly backport from metals #19787
add info implementation to pc #19812
Add custom matchers for completions (fuzzy search for presentation compiler) #19850
Weekly metals backport #19921
Stabilise returned completions by improving deduplication + extra completions for constructors #19976
Fix active param index for empty param lists #20142
Delias type members in hover #20173
Interactive: handle context bounds in extension construct workaround #20201
Fix: prefer non-export definition locations #20252
Add pattern completion for unapply contexts #20274
Don't show enum completions in new keyword context #20304
Chore: Backport changes for presentation compiler #20345
Chore: Bump mtags to latest stable #20442
Weekly metals backport #20542
Port pc find references from metals #20544
Bugfix: Exclude newer LSP4j, which is built on JDK 11 #20771

Quotes

Add missing span to synthesized product mirror #18354
Improve non-static macro implementation error message #18405
Fix scala 2 macros in traits with type parameters #18663
Fallback erasing term references #18731
Patch underlyingArgument to avoid mapping into modules #18923
Avoid crashes on missing positions #19250
Only evaluate transparent inline unapply once #19380
Update staging.Compiler.make documentation #19428
Error instead of StaleSymbol crash for certain cyclic macro dependencies #19549
Refine handling of StaleSymbol type errors #19605
Fix module symbol recovery from NoClassDefFoundError #19645
Fix HOAS pattern example and error message #19655
Add regression test and imporve -Xprint-suspension message #19688
Disallow ill-staged references to local classes #19869
Add regression test for #19909 #19915
Avoid spurious val binding in quote pattern #19948
Fix TermRef prefixes not having their type healed #20102
Improve reporting in staging about the possible use of an incorrect class loader #20137
Add regression test for issue 20309 #20387

REPL

Repl truncation copes with null #17336
Catch stackoverflow errors in the highlighter #19836
Fix validity period of derived SingleDenotations #19983
Fix #18383: Never consider top-level imports as unused in the repl. #20310
Only consider methods with 0 parameters in valueOf #20543

Reflection

Allow to beta reduce curried function applications in quotes reflect #18121
Make check flags for newMethod, newVal and newBind in Quotes API less restrictive #18217
Normalise mirrorType for mirror Synthesis #19199
Fix TypeTreeTypeTest to not match TypeBoundsTrees #19485
Improve message when tree cannot be shown as source #19906
Fix #19732: quotes.reflect.Ref incorrectly casting This to RefTree #19930
Set the inlining phase in the Context used for checking macro trees #20087
Fix erasure crash for Inlined rhs of a context function closure #20398
Fix #20458: do not expose ClassInfo in quotes reflect widenTermRefByName #20468

Reporting

Warn if extension receiver already has member #17543
Deprecation of case class elements #17911
Check if a fatal warning issued in typer is silenced, before converting it into an error #18089
Improve error message for inaccessible types #18406
Elide companion defs to a object extending AnyVal #18451
Add regression test for issue i18493 #18497
Add better explanation to error message #18665
Better error message when accessing private members #18690
Improve assertion error message for Apply and TypeApply #18700
Fix import suggestion error logging #18707
Improve message for discarded pure non-Unit values #18723
Better error message when a pattern match extractor is not found. #18725
Shorten traces for TypeMismatch errors under -explain #18742
Give "did you mean ...?" hints also for simple identifiers #18747
Explicitly state empty package in extendedLocationText #18748
Better error for definition followed by keyword #18752
Better explain message for 'pattern expected' #18753
Add hint for nested quotes missing staged Quotes #18755
Support src filter in -WConf (Closes #17635) #18783
Better error messages for missing commas and more #18785
Avoid diagnostic message forcing crashing the compiler #19113
Make sure that the stacktrace is shown with -Ydebug-unpickling #19115
Improve failure message of enum fromOrdinal/valueOf #19182
Improve asExprOf cast error formatting #19195
Fix type mismatch error confusion between types with same simple name #19204
Properly identify empty bounds in error message #19310
Don't explain erroneous bounds #19338
Better error diagnostics for cyclic references #19408
Unify completion pos usage, fix presentation compiler crash in interpolation #19614
Add formatters for Option, Map, Period, and Atoms #19658
Bugfix: Choose correct signature is signatureHelp for overloaded methods #19707
Fix #19402: emit proper error in absence of using in given definitions #19714
Add error code to diagnostics about unused code #19780
Improve error reporting for missing members #19800
Avoid repetitions in name hints #19975
Add note about type mismatch in automatically inserted apply argument #20023
Make error reporting resilient to exception thrown while reporting #20158
Remove duplicate comma from Matchable selector warning #20159
Generalize warnings for top-level calls to Any or AnyRef methods #20312
Make CheckUnused not slow. #20321
Fix error message on setter with wrong type #20444
Explain unresolvable references better #20477
Add a specific error message for local final defs #20557
Add a specific error message for local final defs #20557

Rewrites

Extra check to avoid converting block expressions on the rhs of an in… #20043

Scala-JS

Fix #18658: Handle varargs of generic types in JSExportsGen. #18659
Consider static and non-static methods as non-double def #19400
Fix #19528: Actually remove Dynamic from interfaces of native JS classes. #19536

Scaladoc

Fix link resolving in scaladoc and fix invalid links in docs #18465
Scaladoc - add option for dynamic side menu #19337
Scaladoc: Fix "case case Foo" in enum's cases #19519
Fix(#19377): show inherited abstract members in dedicated section #19552
Fix(#16610): warn ignored Scaladoc on multiple enum cases #19555
Parse search query param in Scaladoc #19669
Fix #19524: Protect use of HeaderIdGenerator with synchronized. #19884
Prevent HTML/XSS Injection in Scala Search #19980
Fix scaladoc crash on Windows - illegal path character #20311
Relax font-weight reset #20348
Fix handling of right associative extension methods across scaladoc and printers #20467

SemanticDB

Bugfix: in semanticdb make synthetic apply disambiguator consistent w/ Scala 2 implicit #17341
Bugfix: Incorrect semanticdb span on Selectable #18576
fix: semanticdb symbol creation when targetName set #20950
Backport "Export diagnostics (including unused warnings) to SemanticDB" #20315

TASTy format

Fix TASTy source position printer #19105
Homogenize TASTy printer formatting #19139
Used derived types to type arguments of dependent function type #19838

Tooling

Bugfix: Completions for named args in wrong order #18702
Don't add explanation twice #18779
Presentation-compiler: Add synthetic decorations #18951
Make sure that patches for 3.0 are also applied in later versions #19018
Bugfix: Auto imports in worksheets in Scala 3 #19793
Adjust the API name entry for nested classes #20279
Improve source positions emited for synthetic unit in if-conditions #20431
Fix declaring product of straight-to-jar compilation #20592

Transform

List(...) optimization to avoid intermediate array #17166
Add missing span to extension method select #18557
Avoid some intermediate Lists #18572
Properly dealias tuple types when specializing #18724
Fix #18816: Transfer the span of rewired This nodes in fullyParameterizedDef. #18840
Fix condition in prefixIsElidable to prevent compiler crash #18924
Fix purity check for val inside of object #19598
Short-circuit isCheckable with classSymbol #19634
Drop special treatment of function types in overloading resolution #19654
Tweak parameter accessor scheme #19719
Refactor hasOnlyLocalInstantiation to use isLocalToCompilationUnit #19886
Avoid eta-reduction of (..., f: T => R, ...) => f.apply(..) into f #19966
Elide unit binding when beta-reducing #20085
Fix handling of AppliedType aliases in outerPrefix #20190
Fix overloaded default methods test in RefChecks #20218
Correct Java signature for value classes appearing in type arguments #20463
Reimplement support for type aliases in SAM types #18317
Allow SAM types to contain match alias refinements #20092
Allow SAM types to contain multiple refinements #20172

Tuples

Handle TupleXXL in match analysis #19212

Typeclass Derivation

Consider all parents when checking access to the children of a sum #19083

Typer

Fix #17115: Try to normalize while computing typeSize. #18386
Fix failing bounds check on default getter #18419
Add default arguments to derived refined type #18435
Use the unwidened type when casting structural calls #18527
Fix #18649: Use loBound of param types when materializing a context function. #18651
Keep qualifier of Ident when selecting setter #18714
Use constructor's default getters in case class synthetic apply methods #18716
Retract SynthesizeExtMethodReceiver mode when when going deeper in overloading resolution #18759
Avoid crash arising from trying to find conversions from polymorphic singleton types #18760
Identify structural trees on Match Type qualifiers #18765
Encode the name of the attribute in Selectable.selectDynamic #18928
Remove linearization requirement for override ref checks from java classes #18953
Fix #19019: Always type self ValDefs in their outer context. #19030
Check @TargetNAME when subtyping Refined Types #19081
Space: Replace showType & make Space Showable #19370
Reject wildcard types in using clauses #19459
Don't leave underspecified SAM types in the code #19461
Fix #19202: Passing NotNullInfos to a mutable field of a Completer #19463
Also compute base classes of wildcardTypes #19465
Fix(#15784): ident rule for pat match was too strict #19501
Heal occurrences of => T between ElimByName and Erasure #19558
Fix Java record problems (#19578) and (#19386) #19583
Improve when deprecation warnings are emitted #19621
Update phrasing for NotClassType explain error message #19635
Fix(#i18645): overload ext method body in braces didn't compile #19651
Remove dead code in Checking #19678
Fix java typer problems with inner class references and raw types #19747
Approximate MatchTypes with lub of case bodies, if non-recursive #19761
Delay hard argument comparisons #20007
Fix #19789: Merge same TypeParamRef in orDominator #20090
Refactor constant folding of applications #20099
Don't dealias when deciding which arguments to defer #20116
Avoid the TypeVar.inst trap #20160
Suppress "extension method will never be selected" for overrides #20164
Avoid crash when superType does not exist after erasure #20188
Retry constraint.replace after constraint.updateEntry #20399
Add special handling for comparisons with Singleton types #20474
Fix isEffectivelySingleton #20486
Add regression test for #20288 fixed in #20527 #20857
Do not propagate TypeErrors of ops from TypeComparer#tryAlso #21070

Contributors

Thank you to all the contributors who made this release possible 🎉

According to git shortlog -sn --no-merges 3.3.3..3.3.4 these are:

   169 Wojciech Mazur
    74 Dale Wijnand
    72 Martin Odersky
    70 Nicolas Stucki
    29 Jamie Thompson
    25 Sébastien Doeraene
    22 Katarzyna Marek
    19 Eugene Flesselle
    19 Hamza REMMAL
    19 i10416
    18 Matt Bovel
    15 Jędrzej Rochala
    14 Jakub Ciesluk
    14 Som Snytt
    13 Szymon Rodziewicz
    12 Paweł Marks
    12 noti0na1
    11 Jan Chyb
    10 Carl
    10 Guillaume Martres
     6 Kacper Korban
     6 Yilin Wei
     5 Tomasz Godzik
     4 Lorenzo Gabriele
     4 Seth Tisue
     3 Aviv Keller
     3 Bersier
     3 Derek Wickern
     3 Florian3k
     3 Hamza Remmal
     3 Natsu Kagami
     3 Stephane Bersier
     3 aherlihy
     3 dependabot[bot]
     2 110416
     2 Brice Jaglin
     2 Eugene Yokota
     2 Jakub Cieśluk
     2 João Costa
     2 Lucas Nouguier
     2 Pascal Weisenburger
     2 Quentin Bernet
     2 Taro L. Saito
     1 Adam Dąbrowski
     1 Aleksander Boruch-Gruszecki
     1 Ausmarton Zarino Fernandes
     1 Decel
     1 Georgi Krastev
     1 Jisoo Park
     1 John Duffell
     1 João Ferreira
     1 Kenji Yoshida
     1 Lucy Martin
     1 Lukas Rytz
     1 Martin Kucera
     1 Mikołaj Fornal
     1 Nikita Gazarov
     1 Ola Flisbäck
     1 Olga Mazhara
     1 Philippus Baalman
     1 Raphael Jolly
     1 Robert Stoll
     1 Shardul Chiplunkar
     1 Valentin Schneeberger
     1 Yoonjae Jeon
     1 danecek
     1 philippus
     1 rochala

scala/scala3 3.3.4 on GitHub

Highlights of the release

Notable changes

Other changes and fixes

Annotations

Artifacts

Backend

Coverage

Default parameters

Derivation

Desugaring

Documentation

Erasure

Exports

GADTs

Implicits

Incremental Compilation

Inferencing

Infrastructure

Inline

Linting

Match Types

Nullability

Opaque Types

Parser

Pattern Matching

Polyfunctions

Presentation Compiler

Quotes

REPL

Reflection

Reporting

Rewrites

Scala-JS

Scaladoc

SemanticDB

TASTy format

Tooling

Transform

Tuples

Typeclass Derivation

Typer

Contributors

scala/scala3 3.3.4
on GitHub