Merge pull request #9304 from NthPortal/topic/werror-4/PR

build.sbt

@@ -512,15 +512,15 @@ lazy val interactive = configureAsSubproject(project)
   .settings(
     name := "scala-compiler-interactive",
     description := "Scala Interactive Compiler",
-    Compile / scalacOptions ++= Seq("-Xlint", "-Wconf:cat=deprecation:msg=early.initializers:s"),
+    Compile / scalacOptions ++= Seq("-Xlint", "-Wconf:cat=deprecation&msg=early initializers:s"),
   )
   .dependsOn(compiler)
 
 lazy val repl = configureAsSubproject(project)
   .settings(disableDocs)
   .settings(fatalWarningsSettings)
   .settings(publish / skip := true)
-  .settings(Compile / scalacOptions ++= Seq("-Xlint", "-Wconf:cat=deprecation:msg=early.initializers:s"))
+  .settings(Compile / scalacOptions ++= Seq("-Xlint", "-Wconf:cat=deprecation&msg=early initializers:s"))
   .dependsOn(compiler, interactive)
 
 lazy val replFrontend = configureAsSubproject(Project("repl-frontend", file(".") / "src" / "repl-frontend"))
@@ -540,17 +540,24 @@ lazy val replFrontend = configureAsSubproject(Project("repl-frontend", file(".")
 
 lazy val scaladoc = configureAsSubproject(project)
   .settings(disableDocs)
+  .settings(fatalWarningsSettings)
   .settings(publish / skip := true)
   .settings(
     name := "scala-compiler-doc",
     description := "Scala Documentation Generator",
     Compile / unmanagedResources / includeFilter := "*.html" | "*.css" | "*.gif" | "*.png" | "*.js" | "*.txt" | "*.svg" | "*.eot" | "*.woff" | "*.ttf",
     libraryDependencies ++= ScaladocSettings.webjarResources,
-    Compile / resourceGenerators += ScaladocSettings.extractResourcesFromWebjar
+    Compile / resourceGenerators += ScaladocSettings.extractResourcesFromWebjar,
+    Compile / scalacOptions ++= Seq(
+      "-Xlint",
+      "-feature",
+      "-Wconf:cat=deprecation&msg=early initializers:s",
+    ),
   )
   .dependsOn(compiler)
 
 lazy val scalap = configureAsSubproject(project)
+  .settings(fatalWarningsSettings)
   .settings(
     description := "Scala Bytecode Parser",
     // Include decoder.properties
@@ -575,7 +582,8 @@ lazy val scalap = configureAsSubproject(project)
       val excluded = Set("Memoisable.scala", "Result.scala", "Rule.scala", "Rules.scala", "SeqRule.scala")
       xs filter { x => !excluded(x.getName) }
     },
-    Compile / headerResources := Nil
+    Compile / headerResources := Nil,
+    Compile / scalacOptions ++= Seq("-Xlint", "-feature"),
   )
   .dependsOn(compiler)
 

src/compiler/scala/reflect/quasiquotes/Reifiers.scala

@@ -13,7 +13,6 @@
 package scala.reflect
 package quasiquotes
 
-import scala.annotation.nowarn
 import scala.reflect.reify.{Reifier => ReflectReifier}
 import scala.reflect.internal.Flags._
 
@@ -86,7 +85,7 @@ trait Reifiers { self: Quasiquotes =>
         val isVarPattern = tree match { case Bind(name, Ident(nme.WILDCARD)) => true case _ => false }
         val cases =
           if(isVarPattern) {
-            val Ident(name) :: Nil = freevars: @nowarn("msg=match may not be exhaustive")
+            val Ident(name) :: Nil = freevars: @unchecked
             // cq"$name: $treeType => $SomeModule($name)" :: Nil
             CaseDef(Bind(name, Typed(Ident(nme.WILDCARD), TypeTree(treeType))),
               EmptyTree, Apply(Ident(SomeModule), List(Ident(name)))) :: Nil
@@ -422,7 +421,7 @@ trait Reifiers { self: Quasiquotes =>
           case List(elem) if fill.isDefinedAt(elem) => fill(elem)
           case elems => mkList(elems.map(fallback))
         }
-        val head :: tail = group(xs) { (a, b) => !fill.isDefinedAt(a) && !fill.isDefinedAt(b) }: @nowarn("msg=match may not be exhaustive")
+        val head :: tail = group(xs) { (a, b) => !fill.isDefinedAt(a) && !fill.isDefinedAt(b) }: @unchecked
         tail.foldLeft[Tree](reifyGroup(head)) { (tree, lst) => Apply(Select(tree, nme.PLUSPLUS), List(reifyGroup(lst))) }
       }
 

src/compiler/scala/tools/nsc/ast/Trees.scala

@@ -171,7 +171,8 @@ trait Trees extends scala.reflect.internal.Trees { self: Global =>
 
   type ApiTransformer = super.Transformer
 
-  @nowarn("""cat=deprecation&origin=scala\.tools\.nsc\.ast\.Trees\.Transformer""")
+  // TODO: uncomment when deprecating the below
+  // @nowarn("""cat=deprecation&origin=scala\.tools\.nsc\.ast\.Trees\.Transformer""")
   final type AstTransformer = Transformer
 
   // TODO: deprecate when we can cleanly cross-compile without warnings

src/compiler/scala/tools/nsc/backend/jvm/opt/CopyProp.scala

@@ -14,7 +14,7 @@ package scala.tools.nsc
 package backend.jvm
 package opt
 
-import scala.annotation.{nowarn, switch, tailrec}
+import scala.annotation.{switch, tailrec}
 import scala.collection.mutable
 import scala.jdk.CollectionConverters._
 import scala.tools.asm.Opcodes._
@@ -660,7 +660,7 @@ abstract class CopyProp {
 
       @tailrec def tryPairing(): Unit = {
         if (completesStackTop(insn)) {
-          val (store: VarInsnNode, depends) = pairStartStack.pop(): @nowarn("msg=match may not be exhaustive")
+          val (store: VarInsnNode, depends) = pairStartStack.pop(): @unchecked
           addDepends(mkRemovePair(store, insn, depends.toList))
         } else if (pairStartStack.nonEmpty) {
           val (top, topDepends) = pairStartStack.pop()

src/compiler/scala/tools/nsc/tasty/TastyUnpickler.scala

@@ -17,7 +17,6 @@ import scala.tools.tasty.{ErasedTypeRef, Signature, TastyFormat, TastyHeaderUnpi
 import TastyFormat.NameTags._
 import TastyRefs.NameRef
 import TastyName._
-import scala.annotation.nowarn
 import scala.reflect.io.AbstractFile
 
 /**The entry point to TASTy unpickling for nsc, initialises a `TastyUniverse#Context` with the root symbols of a
@@ -42,7 +41,7 @@ object TastyUnpickler {
     val unpickler = new TastyUnpickler[tasty.type](new TastyReader(bytes))(tasty)
     unpickler.readHeader()
     unpickler.readNames()
-    val Some(astReader) = unpickler.readSection("ASTs"): @nowarn("msg=match may not be exhaustive")
+    val Some(astReader) = unpickler.readSection("ASTs"): @unchecked
     val treeUnpickler = new TreeUnpickler[tasty.type](astReader, unpickler.nameAtRef)(tasty)
     treeUnpickler.enterTopLevel(classRoot, objectRoot)
   }

src/compiler/scala/tools/nsc/transform/Erasure.scala

@@ -13,7 +13,7 @@
 package scala.tools.nsc
 package transform
 
-import scala.annotation.{nowarn, tailrec}
+import scala.annotation.tailrec
 import scala.reflect.internal.ClassfileConstants._
 import scala.collection.{immutable, mutable}
 import symtab._
@@ -446,7 +446,7 @@ abstract class Erasure extends InfoTransform
 
       case Block(stats, expr) =>
         // needs `hasSymbolField` check because `supercall` could be a block (named / default args)
-        val (presuper, supercall :: rest) = stats span (t => t.hasSymbolWhich(_ hasFlag PRESUPER)): @nowarn("msg=match may not be exhaustive")
+        val (presuper, supercall :: rest) = stats span (t => t.hasSymbolWhich(_ hasFlag PRESUPER)): @unchecked
         treeCopy.Block(tree, presuper ::: (supercall :: mixinConstructorCalls ::: rest), expr)
 
       case x => throw new MatchError(x)

src/compiler/scala/tools/nsc/transform/OverridingPairs.scala

@@ -25,7 +25,8 @@ import scala.reflect.internal.SymbolPairs
 abstract class OverridingPairs extends SymbolPairs {
   import global._
 
-  @nowarn("""cat=deprecation&origin=scala\.tools\.nsc\.transform\.OverridingPairs\.Cursor""")
+  // TODO: uncomment when deprecating the below
+  // @nowarn("""cat=deprecation&origin=scala\.tools\.nsc\.transform\.OverridingPairs\.Cursor""")
   final type PairsCursor = Cursor
 
   // TODO: deprecate when we can cleanly cross-compile without warnings

src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala

@@ -1901,7 +1901,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers {
     private def addBody(tree: DefDef, source: Symbol): DefDef = {
       val symbol = tree.symbol
       debuglog("specializing body of" + symbol.defString)
-      val DefDef(_, _, tparams, vparams :: Nil, tpt, _) = tree: @nowarn("msg=match may not be exhaustive")
+      val DefDef(_, _, tparams, vparams :: Nil, tpt, _) = tree: @unchecked
       val env = typeEnv(symbol)
       val origtparams = source.typeParams.filter(tparam => !env.contains(tparam) || !isPrimitiveValueType(env(tparam)))
       if (origtparams.nonEmpty || symbol.typeParams.nonEmpty)

src/compiler/scala/tools/nsc/transform/async/ExprBuilder.scala

@@ -12,7 +12,6 @@
 
 package scala.tools.nsc.transform.async
 
-import scala.annotation.nowarn
 import scala.collection.mutable
 import scala.collection.mutable.ListBuffer
 
@@ -329,7 +328,7 @@ trait ExprBuilder extends TransformUtils with AsyncAnalysis {
     private def buildNestedStatesFirstForInlining(nestedTree: Tree, endState: Int): (AsyncState, List[AsyncState]) = {
       val (nestedStats, nestedExpr) = statsAndExpr(nestedTree)
       val nestedBuilder = new AsyncBlockBuilder(nestedStats, nestedExpr, currState, endState, StateTransitionStyle.None, Some(this))
-      val (inlinedState :: Nil, nestedStates) = nestedBuilder.build.partition(_.state == currState): @nowarn("msg=match may not be exhaustive")
+      val (inlinedState :: Nil, nestedStates) = nestedBuilder.build.partition(_.state == currState): @unchecked
       inlinedState.nextStates.foreach(stateBuilder.nextStates += _)
       (inlinedState, nestedStates)
     }
@@ -476,7 +475,7 @@ trait ExprBuilder extends TransformUtils with AsyncAnalysis {
 
       // Filter out dead or trivial states.
       private def filterStates(all: List[AsyncState]): List[AsyncState] = if (compactStates) {
-        val (initial :: Nil, rest) = all.partition(_.state == blockBuilder.startState): @nowarn("msg=match may not be exhaustive")
+        val (initial :: Nil, rest) = all.partition(_.state == blockBuilder.startState): @unchecked
         val map = all.iterator.map(x => (x.state, x)).toMap
         val seen = mutable.HashSet[Int]()
         seen.add(all.last.state)

src/compiler/scala/tools/nsc/transform/patmat/Logic.scala

@@ -13,7 +13,6 @@
 package scala
 package tools.nsc.transform.patmat
 
-import scala.annotation.nowarn
 import scala.collection.mutable
 import scala.collection.immutable.ArraySeq
 import scala.reflect.internal.util.Collections._
@@ -487,7 +486,7 @@ trait Logic extends Debugging  {
     type Solvable
 
     def propToSolvable(p: Prop): Solvable = {
-      val (eqAxiom, pure :: Nil) = removeVarEq(List(p), modelNull = false): @nowarn("msg=match may not be exhaustive")
+      val (eqAxiom, pure :: Nil) = removeVarEq(List(p), modelNull = false): @unchecked
       eqFreePropToSolvable(And(eqAxiom, pure))
     }
 

src/compiler/scala/tools/nsc/transform/patmat/Solving.scala

@@ -14,7 +14,7 @@ package scala.tools.nsc.transform.patmat
 
 import java.util
 
-import scala.annotation.{nowarn, tailrec}
+import scala.annotation.tailrec
 import scala.collection.mutable.ArrayBuffer
 import scala.collection.{immutable, mutable}
 import scala.reflect.internal.util.StatisticsStatics
@@ -249,7 +249,7 @@ trait Solving extends Logic {
                 @inline
                 def /\(a: Lit, b: Lit) = addClauseProcessed(clause(a, b))
 
-                val (mid, xn :: Nil) = tail.splitAt(tail.size - 1): @nowarn("msg=match may not be exhaustive")
+                val (mid, xn :: Nil) = tail.splitAt(tail.size - 1): @unchecked
 
                 // 1 <= x1,...,xn <==>
                 //

src/compiler/scala/tools/nsc/typechecker/NamesDefaults.scala

@@ -17,7 +17,6 @@ import symtab.Flags._
 import scala.collection.mutable
 import scala.reflect.ClassTag
 import PartialFunction.{cond => when}
-import scala.annotation.nowarn
 
 /**
  *  @author Lukas Rytz
@@ -529,7 +528,7 @@ trait NamesDefaults { self: Analyzer =>
     val namelessArgs = {
       var positionalAllowed = true
       def stripNamedArg(arg: NamedArg, argIndex: Int): Tree = {
-        val NamedArg(Ident(name), rhs) = arg: @nowarn("msg=match may not be exhaustive")
+        val NamedArg(Ident(name), rhs) = arg: @unchecked
         params indexWhere (p => matchesName(p, name, argIndex)) match {
           case -1 =>
             val warnVariableInScope = !currentRun.isScala3 && context0.lookupSymbol(name, _.isVariable).isSuccess

src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala

@@ -21,7 +21,6 @@ package typechecker
 
 import scala.collection.{immutable, mutable}
 import mutable.ListBuffer
-import scala.annotation.nowarn
 import scala.tools.nsc.Reporting.WarningCategory
 import symtab.Flags._
 
@@ -144,7 +143,7 @@ abstract class SuperAccessors extends transform.Transform with transform.TypingT
       }
 
     private def transformSuperSelect(sel: Select): Tree = {
-      val Select(sup @ Super(_, mix), name) = sel: @nowarn("msg=match may not be exhaustive")
+      val Select(sup @ Super(_, mix), name) = sel: @unchecked
       val sym   = sel.symbol
       val clazz = sup.symbol
 
@@ -485,7 +484,7 @@ abstract class SuperAccessors extends transform.Transform with transform.TypingT
         newAcc setInfoAndEnter accType(newAcc)
 
         val code = DefDef(newAcc, {
-          val (receiver :: _) :: tail = newAcc.paramss: @nowarn("msg=match may not be exhaustive")
+          val (receiver :: _) :: tail = newAcc.paramss: @unchecked
           val base: Tree              = Select(Ident(receiver), sym)
           foldLeft2(tail, sym.info.paramss)(base){ (acc, params, pps) =>
             val y = map2(params, pps)( (param, pp) =>  makeArg(param, receiver, pp.tpe))
@@ -550,7 +549,7 @@ abstract class SuperAccessors extends transform.Transform with transform.TypingT
         val accessorType = MethodType(params, UnitTpe)
 
         protAcc setInfoAndEnter accessorType
-        val obj :: value :: Nil = params: @nowarn("msg=match may not be exhaustive")
+        val obj :: value :: Nil = params: @unchecked
         storeAccessorDefinition(clazz, DefDef(protAcc, Assign(Select(Ident(obj), field.name), Ident(value))))
 
         protAcc

src/compiler/scala/tools/nsc/typechecker/Typers.scala

@@ -1695,7 +1695,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper
     private def normalizeFirstParent(parents: List[Tree]): List[Tree] = {
       @annotation.tailrec
       def explode0(parents: List[Tree]): List[Tree] = {
-        val supertpt :: rest = parents: @nowarn("msg=match may not be exhaustive") // parents is always non-empty here - it only grows
+        val supertpt :: rest = parents: @unchecked // parents is always non-empty here - it only grows
         if (supertpt.tpe.typeSymbol == AnyClass) {
           supertpt setType AnyRefTpe
           parents

src/scaladoc/scala/tools/nsc/doc/Index.scala

@@ -12,7 +12,7 @@
 
 package scala.tools.nsc.doc
 
-import scala.collection._
+import scala.collection.immutable.{SortedMap, SortedSet}
 
 trait Index {
   type SymbolMap = SortedMap[String, SortedSet[model.MemberEntity]]

src/scaladoc/scala/tools/nsc/doc/ScaladocAnalyzer.scala

@@ -163,7 +163,7 @@ abstract class ScaladocSyntaxAnalyzer[G <: Global](val global: G) extends Syntax
      */
     override def discardDocBuffer() = {
       import scala.tools.nsc.doc.base.comment.Comment
-      val doc = flushDoc
+      val doc = flushDoc()
       // tags that make a local double-star comment look unclean, as though it were API
       def unclean(comment: Comment): Boolean = {
         import comment._
@@ -182,7 +182,7 @@ abstract class ScaladocSyntaxAnalyzer[G <: Global](val global: G) extends Syntax
     override def withPatches(patches: List[BracePatch]) = new ScaladocUnitParser(unit, patches)
 
     override def joinComment(trees: => List[Tree]): List[Tree] = {
-      val doc = in.flushDoc
+      val doc = in.flushDoc()
       if ((doc ne null) && doc.raw.length > 0) {
         log(s"joinComment(doc=$doc)")
         val joined = trees map {

src/scaladoc/scala/tools/nsc/doc/Settings.scala

@@ -15,6 +15,7 @@ package doc
 
 import java.io.File
 
+import scala.annotation.nowarn
 import scala.tools.nsc.settings.{DefaultPathFactory, PathFactory}
 
 /** An extended version of compiler settings, with additional Scaladoc-specific options.
@@ -349,6 +350,7 @@ class Settings(error: String => Unit, val printMsg: String => Unit = println(_),
     /** Dirty, dirty, dirty hack: the value params conversions can all kick in -- and they are disambiguated by priority
      *  but showing priority in scaladoc would make no sense -- so we have to manually remove the conversions that we
      *  know will never get a chance to kick in. Anyway, DIRTY DIRTY DIRTY! */
+    @nowarn("cat=lint-nonlocal-return")
     def valueClassFilter(value: String, conversionName: String): Boolean = {
       val valueName = value.toLowerCase
       val otherValues = valueClassList.filterNot(_ == valueName)

src/scaladoc/scala/tools/nsc/doc/base/CommentFactoryBase.scala

@@ -15,7 +15,7 @@ package doc
 package base
 
 import base.comment._
-import scala.annotation.tailrec
+import scala.annotation.{nowarn, tailrec}
 import scala.collection._
 import scala.util.matching.Regex
 import scala.reflect.internal.util.Position
@@ -183,11 +183,11 @@ trait CommentFactoryBase { this: MemberLookupBase =>
 
   /** The start of a Scaladoc code block */
   private val CodeBlockStartRegex =
-    new Regex("""(.*?)((?:\{\{\{)|(?:\u000E<pre(?: [^>]*)?>\u000E))(.*)""")
+    new Regex("""(.*?)((?:\{\{\{)|(?:<pre(?: [^>]*)?>))(.*)""")
 
   /** The end of a Scaladoc code block */
   private val CodeBlockEndRegex =
-    new Regex("""(.*?)((?:\}\}\})|(?:\u000E</pre>\u000E))(.*)""")
+    new Regex("""(.*?)((?:\}\}\})|(?:</pre>))(.*)""")
 
   /** A key used for a tag map. The key is built from the name of the tag and
     * from the linked symbol if the tag has one.
@@ -771,12 +771,13 @@ trait CommentFactoryBase { this: MemberLookupBase =>
       }
 
       // TODO: Abandon table parsing when the delimiter is missing instead of fixing and continuing.
-      val delimiterRow :: dataRows = if (rows.nonEmpty)
-        rows.toList
-      else {
-        reportError(pos, "Fixing missing delimiter row", site)
-        Row(Cell(Paragraph(Text("-")) :: Nil) :: Nil) :: Nil
-      }
+      val delimiterRow :: dataRows = {
+        if (rows.nonEmpty) rows.toList
+        else {
+          reportError(pos, "Fixing missing delimiter row", site)
+          Row(Cell(Paragraph(Text("-")) :: Nil) :: Nil) :: Nil
+        }
+      }: @nowarn("msg=match may not be exhaustive")
 
       if (delimiterRow.cells.isEmpty) sys.error("TODO: Handle table with empty delimiter row")
 
@@ -893,15 +894,26 @@ trait CommentFactoryBase { this: MemberLookupBase =>
         else if (check(",,")) subscript()
         else if (check("[[")) link()
         else {
-          val str = readUntil { char == safeTagMarker || check("''") || char == '`' || check("__") || char == '^' || check(",,") || check("[[") || isInlineEnd || checkParaEnded || char == endOfLine }
+          val str = readUntil {
+            char == safeTagMarker ||
+              check("''") ||
+              char == '`' ||
+              check("__") ||
+              char == '^' ||
+              check(",,") ||
+              check("[[") ||
+              isInlineEnd ||
+              checkParaEnded() ||
+              char == endOfLine
+          }
           Text(textTransform(str))
         }
       }
 
       val inlines: List[Inline] = {
         val iss = mutable.ListBuffer.empty[Inline]
         iss += inline0()
-        while (!isInlineEnd && !checkParaEnded) {
+        while (!isInlineEnd && !checkParaEnded()) {
           val skipEndOfLine = if (char == endOfLine) {
             nextChar()
             true