Highlights of the release

Support records in JavaParsers #16762
Port JVM backend refactor from Scala 2 #15322

Other changes and fixes

Backend

Disallow mixins where super calls bind to vals #16908
Fix #15107: Avoid re-emitting a LineNumber after only LabelNodes. #16813

Coverage

Fix #17042: Preserve the shape of secondary ctors in instrumentCoverage. #17111

Default parameters

Dupe fix when finding default arg getters #17058

Documentation

Fix: ensure syntax blocks for ebnf are marked as such #16837

Erasure

Handle @companionClass and @companionMethod meta-annotations #17091

Extension Methods

Support extension methods imported from different objects #17050

GADTs

Fix tuple member selection so it works with GADT healing #16766
Fix upper bound constraints, that are higher-kinded #16744
Split out immutable GadtConstraint #16602

Implicits

Improve subtyping check for not yet eta-expanded higher kinded types #17139
Harden tpd.Apply/TypeApply in case of errors #16887
Try to be more subtle when inferring type parameters of class parents #16896
Include P in the implicit scope of P.this.type #17088
Do not compute protoFormal if param.tpt is empty #18288

Incremental Compilation

Fix under-compilation when the method type in a SAM changes #16996

Infrastructure

Set reference version to 3.3.0-RC6 #17504
Fix #17119: Download Coursier from GitHub directly #17141

Inline

Remove NamedArg from inlined arguments #17228
Don't generate a Select for a TermRef with NoPrefix #16754
Prepare bodies of inline forwarders eagerly #16757
Do not remove inline method implementations until PruneErasedDefs #17408

Java Interop

ClassfileParser: allow missing param names (for JDK 21) #17536

Linting

Improve -Wunused: locals, privates with unset vars warning #16639 #17160
Fix wunused false positive when deriving alias type #17157
Port -Wnonunit-statement setting for dotty #16936

Match Types

Fix #13757: Explicitly disallow higher-kinded scrutinees of match types. #17322
Fix match type reduction with wildcard type arguments #17065
Fix check whether classtag can be generated for match types #16708

Parser

Allow lines starting with . to fall outside previous indentation widths #17056

Pattern Matching

Fix #11541: Specialize ClassTag[T] in exhaustivity check #17385
Check outer class prefixes in type projections when pattern matching #17136
Make unchecked cases non-@unchecked and non-unreachable #16958
Fix #16899: Better handle X instanceOf P where X is T1 | T2 #17382
Fix regression in exhaustivity of HK types #18303

Pickling

ClassfileParser: Avoid cycle when accessing companion in inner class lookup #16882

Polyfunctions

Fix type aliases in beta-reduction of polyfunctions #17054

Quotes

Register paramProxy and thisProxy in Quote type #17541
Only check newVal/newMethod privateWithin on -Xcheck-macros #17437
Unencode quote and splice trees #17342
Correctly type Expr.ofTupleFromSeq for arity > 22 #17261
Use TermRef to distinguish distinct Type[T] instances #17205
Check level consistency of SingletonTypeTree as a type #17209
Fix splice type variable pattern detection #17048
Avoid creation of @SplicedType quote local refrences #17051
Dealias type references when healing types in quotes #17049
Replace quoted type variables in signature of HOAS pattern result #16951
Beta-reduce directly applied PolymorphicFunction #16623
Use Object.toString for quoted.{Expr, Type} #16663
Fix Splicer.isEscapedVariable #16838
Fix references to class members defined in quotes #17107
Handle pickled forward references in pickled expressions #16855
Fix #16615 - crashes of path dependent types in spliced Type.of #16773
Disallow local term references in staged types #16362
Refactor level checking / type healing logic #17082
Dealias quoted types when staging #17059
Fix quotes with references to path dependent types #17081
Make arguments order in quote hole deterministic #17405
Only transform the body of the quote with QuoteTransformer #17451
Place staged type captures in Quote AST #17424
Add SplicePattern AST to parse and type quote pattern splices #17396
Dealias types in `New`` before matching quotes #17615

Reflection

-Xcheck-macros: add hint when a symbol in created twice #16733
Assert that symbols created using reflect API have correct privateWithin symbols #17352
Fix reflect.LambdaType type test #16972
Improve New/Select -Ycheck message #16746
Improve error message for CyclicReference in macros #16749

REPL

Always load REPL classes in macros including the output directory #16866

Reporting

Improve missing argument list error #17126
Improve implicit parameter error message with aliases #17125
Improve "constructor proxy shadows outer" handling #17154
Clarify ambiguous reference error message #16137
Hint about forbidden combination of implicit values and conversions #16735
Attach explanation message to diagnostic message #16787
Propagate implicit search errors from implicit macros #16840
Detail UnapplyInvalidReturnType error message #17167
Add way to debug -Xcheck-macros tree checking #16973
Enrich and finesse compiler crash reporting #17031
Allow @implicitNotFound messages as explanations #16893
Include top-level symbols from same file in outer ambiguity error #17033
Do not issue deprecation warnings when declaring deprecated case classes #17165

Scala-JS

Fix #17344: Make implicit references to this above dynamic imports explicit. #17357
Fix #12621: Better error message for JS trait ctor param. #16811
Fix #16801: Handle Closure's of s.r.FunctionXXL. #16809
Fix #17549: Unify how Memoize and Constructors decide what fields need storing. #17560

Scaladoc

Feat: Add a blog configuration with yaml #17214
Don't render the "$" for module #17302
Fix: Add scrollbar to the sidebar #17203
Scaladoc: fix crash when processing extends call #17260
Fix: Modify the CSS so that the logo of the generated documentation is adaptive #17172
Fix: Remove the duplicate parameter when generating the scaladoc. #17097
Fix: padding top in mobile version #17019
Fix: tap target of the menu in Mobile version #17018
Scaladoc: Fix expand icon not changing on anchor link #17053
Scaladoc: fix inkuire generation for PolyTypes #17129
Re port scroll bar #17463
Handle empty files and truncated YAML front matter #17527

SemanticDB

Make sure symbol exists before calling owner #16860
Support LambdaType (convert from HKTypeLambda) #16056

Specification

Apply class-shadowing.md to the Spec #16839
Adding base for future Spec into the compiler repo #16825

Standard Library

Optimization: avoid NotGiven allocations #17090

Tooling

Disable ExtractSemanticDB phase when writing to output directory defined as JAR. #16790
Print owner of bind symbol with -Yprint-debug-owners #16854
Small fixes to allow using Metals with scaladoc with sbt #16816

Transform

Move CrossVersionChecks before FirstTransform #17301
Fix needsOuterIfReferenced #17159
Drop incorrect super accessor in trait subclass #17062
Generate toString only for synthetic companions of case classes #16890
Check trait constructor for accessibility even if not called at Typer #17094
Fix #17435: A simpler fix #17436

Typer

Preserve type bounds for inlined definitions in posttyper #17190
Change logic to find members of recursive types #17386
Recognize named arguments in isFunctionWithUnknownParamType #17161
Better comparisons for type projections #17092
Allow selectDynamic and applyDynamic to be extension methods #17106
Fix use of accessibleFrom when finding default arg getters #16977
Map class literal constant types #16988
Always use adapted type in withDenotation #16901
Restrict captureWildcards to only be used if needed #16799
Don't capture wildcards if in closure or by-name #16732
Infer: Don't minimise to Nothing if there's an upper bound #16786
Perform Matchable check only if type test is needed #16824
Don't eta expand unary varargs methods #16892
Fix beta-reduction with Nothing and null args #16938
Generate kind-correct wildcards when selecting from a wildcard #17025
Fix #16405 ctd - wildcards prematurely resolving to Nothing #16764
Test: add regression test for #7790 #17473
Properly handle AnyVals as refinement members of Selectables #16286
Fix accessibleType for package object prefixes #18057
Add clause for protected visibility from package objects #18134
Revert "Include top-level symbols from same file in outer ambiguity error" #17438
Heal stage inconsistent prefixes of type projections #18239
Fix regression #17245: Overloaded methods with ClassTags #18286
Disallow taking singleton types of packages again #18232
A slightly more conservative version of #14218 #18352
Record failures to adapt application arguments #18269
Refine infoDependsOnPrefix #18204
Tweak selection from self types #18467

Contributors

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

According to git shortlog -sn --no-merges 3.3.0..3.3.1-RC1 these are:

   148 Nicolas Stucki
    65 Martin Odersky
    51 Szymon Rodziewicz
    49 Dale Wijnand
    49 Quentin Bernet
    38 Chris Kipp
    19 David Hua
    18 Lucas
    18 ysthakur
    15 Fengyun Liu
    15 Paweł Marks
    14 Guillaume Martres
    14 Jamie Thompson
    11 Sébastien Doeraene
     9 Timothée Andres
     8 Kacper Korban
     7 Matt Bovel
     7 Som Snytt
     6 Julien Richard-Foy
     6 Lucas Leblanc
     5 Michał Pałka
     4 Anatolii Kmetiuk
     4 Guillaume Raffin
     4 Paul Coral
     4 Wojciech Mazur
     4 Yichen Xu
     3 Decel
     3 Jan Chyb
     2 Adrien Piquerez
     2 Arman Bilge
     2 Carl
     2 Florian3k
     2 Kenji Yoshida
     2 Michael Pilquist
     2 Natsu Kagami
     2 Seth Tisue
     2 Tomasz Godzik
     2 Vasil Vasilev
     2 Yadu Krishnan
     1 Bersier
     1 Flavio Brasil
     1 Jan-Pieter van den Heuvel
     1 Lukas Rytz
     1 Miles Yucht
     1 Mohammad Yousuf Minhaj Zia
     1 Ondra Pelech
     1 Philippus
     1 Rikito Taniguchi
     1 Simon R
     1 brandonspark
     1 github-actions[bot]
     1 liang3zy22
     1 s.bazarsadaev
     1 Łukasz Wroński