Make compiler sources invariant under syntax rewritings

compiler/src/dotty/tools/dotc/Driver.scala

@@ -59,16 +59,15 @@ class Driver {
     MacroClassLoader.init(ctx)
     Positioned.updateDebugPos(ctx)
 
-    if (!ctx.settings.YdropComments.value(ctx) || ctx.mode.is(Mode.ReadComments)) {
+    if (!ctx.settings.YdropComments.value(ctx) || ctx.mode.is(Mode.ReadComments))
       ctx.setProperty(ContextDoc, new ContextDocstrings)
-    }
 
     val fileNames = CompilerCommand.checkUsage(summary, sourcesRequired)(ctx)
     fromTastySetup(fileNames, ctx)
   }
 
   /** Setup extra classpath and figure out class names for tasty file inputs */
-  protected def fromTastySetup(fileNames0: List[String], ctx0: Context): (List[String], Context) = {
+  protected def fromTastySetup(fileNames0: List[String], ctx0: Context): (List[String], Context) =
     if (ctx0.settings.fromTasty.value(ctx0)) {
       // Resolve classpath and class names of tasty files
       val (classPaths, classNames) = fileNames0.flatMap { name =>
@@ -98,8 +97,8 @@ class Driver {
       val fullClassPath = (classPaths1 :+ ctx1.settings.classpath.value(ctx1)).mkString(java.io.File.pathSeparator)
       ctx1.setSetting(ctx1.settings.classpath, fullClassPath)
       (classNames, ctx1)
-    } else (fileNames0, ctx0)
-  }
+    }
+    else (fileNames0, ctx0)
 
   /** Entry point to the compiler that can be conveniently used with Java reflection.
    *

compiler/src/dotty/tools/dotc/Run.scala

@@ -102,7 +102,8 @@ class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with Constraint
   def compile(fileNames: List[String]): Unit = try {
     val sources = fileNames.map(ctx.getSource(_))
     compileSources(sources)
-  } catch {
+  }
+  catch {
     case NonFatal(ex) =>
       ctx.echo(i"exception occurred while compiling $units%, %")
       throw ex
@@ -114,11 +115,12 @@ class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with Constraint
    *  or we need to assemble phases on each run, and take -Yskip, -Ystop into
    *  account. I think the latter would be preferable.
    */
-  def compileSources(sources: List[SourceFile]): Unit =
+  def compileSources(sources: List[SourceFile]): Unit = {
     if (sources forall (_.exists)) {
       units = sources.map(CompilationUnit(_))
       compileUnits()
     }
+  }
 
   def compileUnits(us: List[CompilationUnit]): Unit = {
     units = us
@@ -150,24 +152,23 @@ class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with Constraint
       var lastPrintedTree: PrintedTree = NoPrintedTree
       val profiler = ctx.profiler
 
-      for (phase <- ctx.base.allPhases)
+      for (phase <- ctx.base.allPhases) {
         if (phase.isRunnable)
           Stats.trackTime(s"$phase ms ") {
             val start = System.currentTimeMillis
             val profileBefore = profiler.beforePhase(phase)
             units = phase.runOn(units)
             profiler.afterPhase(phase, profileBefore)
-            if (ctx.settings.Xprint.value.containsPhase(phase)) {
-              for (unit <- units) {
+            if (ctx.settings.Xprint.value.containsPhase(phase))
+              for (unit <- units)
                 lastPrintedTree =
                   printTree(lastPrintedTree)(ctx.fresh.setPhase(phase.next).setCompilationUnit(unit))
-              }
-            }
             ctx.informTime(s"$phase ", start)
             Stats.record(s"total trees at end of $phase", ast.Trees.ntrees)
             for (unit <- units)
               Stats.record(s"retained typed trees at end of $phase", unit.tpdTree.treeSize)
           }
+      }
 
       profiler.finished()
     }
@@ -189,7 +190,7 @@ class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with Constraint
    *  If `typeCheck = true`, also run typer on the compilation unit, and set
    *  `rootTreeOrProvider`.
    */
-  def lateCompile(file: AbstractFile, typeCheck: Boolean)(implicit ctx: Context): Unit =
+  def lateCompile(file: AbstractFile, typeCheck: Boolean)(implicit ctx: Context): Unit = {
     if (!files.contains(file) && !lateFiles.contains(file)) {
       lateFiles += file
       val unit = CompilationUnit(ctx.getSource(file.path))
@@ -208,6 +209,7 @@ class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with Constraint
       }
       process()(runContext.fresh.setCompilationUnit(unit))
     }
+  }
 
   private sealed trait PrintedTree
   private /*final*/ case class SomePrintedTree(phase: String, tree: String) extends PrintedTree

compiler/src/dotty/tools/dotc/ast/Desugar.scala

@@ -308,12 +308,12 @@ object desugar {
    *    case '{ @patternBindHole def `$a`(...) = ...; ... `$a`() ... } => a
    *  ```
    */
-  def transformQuotedPatternName(tree: ValOrDefDef)(implicit ctx: Context): ValOrDefDef = {
+  def transformQuotedPatternName(tree: ValOrDefDef)(implicit ctx: Context): ValOrDefDef =
     if (ctx.mode.is(Mode.QuotedPattern) && !isBackquoted(tree) && tree.name != nme.ANON_FUN && tree.name.startsWith("$")) {
       val mods = tree.mods.withAddedAnnotation(New(ref(defn.InternalQuoted_patternBindHoleAnnot.typeRef)).withSpan(tree.span))
       tree.withMods(mods)
-    } else tree
-  }
+    }
+    else tree
 
   /** Add an explicit ascription to the `expectedTpt` to every tail splice.
    *
@@ -926,7 +926,8 @@ object desugar {
       val patternBindHoleAnnot = New(ref(defn.InternalQuoted_patternBindHoleAnnot.typeRef)).withSpan(tree.span)
       val mods = tree.mods.withAddedAnnotation(patternBindHoleAnnot)
       tree.withMods(mods)
-    } else tree
+    }
+    else tree
   }
 
   /** The normalized name of `mdef`. This means
@@ -953,7 +954,8 @@ object desugar {
         impl.body.find {
           case dd: DefDef if dd.mods.is(Extension) => true
           case _ => false
-        } match {
+        }
+        match {
           case Some(DefDef(name, _, (vparam :: _) :: _, _, _)) =>
             s"${name}_of_${inventTypeName(vparam.tpt)}"
           case _ =>
@@ -1007,7 +1009,7 @@ object desugar {
         case id: Ident =>
           expandSimpleEnumCase(id.name.asTermName, mods,
             Span(id.span.start, id.span.end, id.span.start))
-    }
+      }
     else {
       val pats1 = if (tpt.isEmpty) pats else pats map (Typed(_, tpt))
       pats1 map (makePatDef(pdef, mods, _, rhs))
@@ -1068,7 +1070,7 @@ object desugar {
         if (tupleOptimizable) // include `_`
           pat match {
             case Tuple(pats) =>
-            pats.map { case id: Ident => id -> TypeTree() }
+              pats.map { case id: Ident => id -> TypeTree() }
           }
         else getVariables(pat)  // no `_`
 
@@ -1127,11 +1129,12 @@ object desugar {
     case tree: MemberDef =>
       var tested: MemberDef = tree
       def fail(msg: String) = ctx.error(msg, tree.sourcePos)
-      def checkApplicable(flag: Flag, test: MemberDefTest): Unit =
+      def checkApplicable(flag: Flag, test: MemberDefTest): Unit = {
         if (tested.mods.is(flag) && !test.applyOrElse(tree, (md: MemberDef) => false)) {
           fail(i"modifier `${flag.flagsString}` is not allowed for this definition")
           tested = tested.withMods(tested.mods.withoutFlags(flag))
         }
+      }
       checkApplicable(Opaque, legalOpaque)
       tested
     case _ =>
@@ -1296,7 +1299,7 @@ object desugar {
       if (isGenericTuple) Apply(Select(refOfDef(param), nme.apply), Literal(Constant(n)))
       else Select(refOfDef(param), nme.selectorName(n))
     val vdefs =
-      params.zipWithIndex.map{
+      params.zipWithIndex.map {
         case (param, idx) =>
           DefDef(param.name, Nil, Nil, TypeTree(), selector(idx)).withSpan(param.span)
       }
@@ -1338,7 +1341,7 @@ object desugar {
       .withSpan(original.span.withPoint(named.span.start))
     val mayNeedSetter = valDef(vdef)
     mayNeedSetter
-   }
+  }
 
   private def derivedDefDef(original: Tree, named: NameTree, tpt: Tree, rhs: Tree, mods: Modifiers)(implicit src: SourceFile) =
     DefDef(named.name.asTermName, Nil, Nil, tpt, rhs)
@@ -1551,7 +1554,8 @@ object desugar {
           RefinedTypeTree(polyFunctionTpt, List(
             DefDef(nme.apply, applyTParams, List(applyVParams), res, EmptyTree)
           ))
-        } else {
+        }
+        else {
           // Desugar [T_1, ..., T_M] -> (x_1: P_1, ..., x_N: P_N) => body
           // Into    new scala.PolyFunction { def apply[T_1, ..., T_M](x_1: P_1, ..., x_N: P_N) = body }
 
@@ -1606,7 +1610,8 @@ object desugar {
           Annotated(
             AppliedTypeTree(ref(seqType), t),
             New(ref(defn.RepeatedAnnot.typeRef), Nil :: Nil))
-        } else {
+        }
+        else {
           assert(ctx.mode.isExpr || ctx.reporter.errorsReported || ctx.mode.is(Mode.Interactive), ctx.mode)
           Select(t, op.name)
         }
@@ -1692,8 +1697,9 @@ object desugar {
   private def getVariables(tree: Tree)(implicit ctx: Context): List[VarInfo] = {
     val buf = ListBuffer[VarInfo]()
     def seenName(name: Name) = buf exists (_._1.name == name)
-    def add(named: NameTree, t: Tree): Unit =
+    def add(named: NameTree, t: Tree): Unit = {
       if (!seenName(named.name) && named.name.isTermName) buf += ((named, t))
+    }
     def collect(tree: Tree): Unit = tree match {
       case Bind(nme.WILDCARD, tree1) =>
         collect(tree1)

compiler/src/dotty/tools/dotc/ast/MainProxies.scala

@@ -45,7 +45,7 @@ object MainProxies {
     def pos = mainFun.sourcePos
     val argsRef = Ident(nme.args)
 
-    def addArgs(call: untpd.Tree, mt: MethodType, idx: Int): untpd.Tree = {
+    def addArgs(call: untpd.Tree, mt: MethodType, idx: Int): untpd.Tree =
       if (mt.isImplicitMethod) {
         ctx.error(s"@main method cannot have implicit parameters", pos)
         call
@@ -71,7 +71,6 @@ object MainProxies {
             call1
         }
       }
-    }
 
     var result: List[TypeDef] = Nil
     if (!mainFun.owner.isStaticOwner)

compiler/src/dotty/tools/dotc/ast/NavigateAST.scala

@@ -97,7 +97,8 @@ object NavigateAST {
           case _ =>
         }
         childPath(p.productIterator, p :: path)
-      } else path
+      }
+      else path
     singlePath(from, Nil)
   }
 }

compiler/src/dotty/tools/dotc/ast/Positioned.scala

@@ -38,9 +38,8 @@ abstract class Positioned(implicit @constructorOnly src: SourceFile) extends Pro
   /** The span part of the item's position */
   def span: Span = mySpan
 
-  def span_=(span: Span): Unit = {
+  def span_=(span: Span): Unit =
     mySpan = span
-  }
 
   uniqueId = src.nextId
   span = envelope(src)
@@ -58,9 +57,8 @@ abstract class Positioned(implicit @constructorOnly src: SourceFile) extends Pro
     else {
       val newpd: this.type =
         if (mySpan.isSynthetic) {
-          if (!mySpan.exists && span.exists) {
+          if (!mySpan.exists && span.exists)
             envelope(source, span.startPos) // fill in children spans
-          }
           this
         }
         else cloneIn(source)
@@ -109,12 +107,11 @@ abstract class Positioned(implicit @constructorOnly src: SourceFile) extends Pro
         else if (span1.start == MaxOffset)
           // No positioned child was found
           NoSpan
-        else {
+        else
           ///println(s"revisit $uniqueId with $span1")
           // We have some children left whose span could not be assigned.
           // Go through it again with the known start position.
           includeChildren(span1.startPos, 0)
-        }
       span2.toSynthetic
   }
 
@@ -145,7 +142,7 @@ abstract class Positioned(implicit @constructorOnly src: SourceFile) extends Pro
           found = isParent(productElement(n))
         }
         found
-      }
+    }
   }
 
   /** A hook that can be overridden if overlap checking in `checkPos` should be
@@ -232,7 +229,8 @@ abstract class Positioned(implicit @constructorOnly src: SourceFile) extends Pro
           n += 1
         }
     }
-  } catch {
+  }
+  catch {
     case ex: AssertionError =>
       println(i"error while checking $this")
       throw ex
@@ -242,7 +240,6 @@ abstract class Positioned(implicit @constructorOnly src: SourceFile) extends Pro
 object Positioned {
   @sharable private[Positioned] var debugId = Int.MinValue
 
-  def updateDebugPos(implicit ctx: Context): Unit = {
+  def updateDebugPos(implicit ctx: Context): Unit =
     debugId = ctx.settings.YdebugTreeWithId.value
-  }
 }

compiler/src/dotty/tools/dotc/ast/TreeInfo.scala

@@ -401,7 +401,7 @@ trait TypedTreeInfo extends TreeInfo[Type] { self: Trees.Instance[Type] =>
           || fn.symbol.isPrimaryConstructor && fn.symbol.owner.isNoInitsClass) // TODO: include in isStable?
         minOf(exprPurity(fn), args.map(exprPurity)) `min` Pure
       else if (fn.symbol.is(Erased)) Pure
-      else if (fn.symbol.isStableMember /* && fn.symbol.is(Lazy) */)
+      else if (fn.symbol.isStableMember) /* && fn.symbol.is(Lazy) */
         minOf(exprPurity(fn), args.map(exprPurity)) `min` Idempotent
       else Impure
     case Typed(expr, _) =>
@@ -686,15 +686,14 @@ trait TypedTreeInfo extends TreeInfo[Type] { self: Trees.Instance[Type] =>
   def defPath(sym: Symbol, root: Tree)(implicit ctx: Context): List[Tree] = trace.onDebug(s"defpath($sym with position ${sym.span}, ${root.show})") {
     require(sym.span.exists, sym)
     object accum extends TreeAccumulator[List[Tree]] {
-      def apply(x: List[Tree], tree: Tree)(implicit ctx: Context): List[Tree] = {
+      def apply(x: List[Tree], tree: Tree)(implicit ctx: Context): List[Tree] =
         if (tree.span.contains(sym.span))
           if (definedSym(tree) == sym) tree :: x
           else {
             val x1 = foldOver(x, tree)
             if (x1 ne x) tree :: x1 else x1
           }
         else x
-      }
     }
     accum(Nil, root)
   }

compiler/src/dotty/tools/dotc/ast/TreeMapWithImplicits.scala

@@ -28,7 +28,7 @@ class TreeMapWithImplicits extends tpd.TreeMap {
 
     @tailrec def traverse(curStats: List[Tree])(implicit ctx: Context): List[Tree] = {
 
-      def recur(stats: List[Tree], changed: Tree, rest: List[Tree])(implicit ctx: Context): List[Tree] = {
+      def recur(stats: List[Tree], changed: Tree, rest: List[Tree])(implicit ctx: Context): List[Tree] =
         if (stats eq curStats) {
           val rest1 = transformStats(rest, exprOwner)
           changed match {
@@ -37,7 +37,6 @@ class TreeMapWithImplicits extends tpd.TreeMap {
           }
         }
         else stats.head :: recur(stats.tail, changed, rest)
-      }
 
       curStats match {
         case stat :: rest =>
@@ -123,5 +122,5 @@ class TreeMapWithImplicits extends tpd.TreeMap {
         tree
     }
   }
-
 }
+

compiler/src/dotty/tools/dotc/ast/TreeTypeMap.scala

@@ -189,9 +189,8 @@ class TreeTypeMap(
       val origDcls = cls.info.decls.toList
       val mappedDcls = ctx.mapSymbols(origDcls, tmap)
       val tmap1 = tmap.withMappedSyms(origDcls, mappedDcls)
-      if (symsChanged) {
+      if (symsChanged)
         origDcls.lazyZip(mappedDcls).foreach(cls.asClass.replace)
-      }
       tmap1
     }
     if (symsChanged || (fullMap eq substMap)) fullMap