Upgrade to scalameta 3.7.0 with default settings.

build.sbt

@@ -1,4 +1,3 @@
-import sbt.ScriptedPlugin
 import sbt.ScriptedPlugin._
 import Dependencies._
 
@@ -147,6 +146,7 @@ val cli = MultiScalaProject(
     mainClass in assembly := Some("scalafix.cli.Cli"),
     assemblyJarName in assembly := "scalafix.jar",
     libraryDependencies ++= Seq(
+      metacp,
       "com.github.alexarchambault" %% "case-app" % "1.2.0",
       "org.typelevel" %% "paiges-core" % "0.2.0",
       "com.martiansoftware" % "nailgun-server" % "0.9.1",
@@ -207,10 +207,18 @@ val scalafixSbt = MultiSbtProject(
   ).enablePlugins(BuildInfoPlugin)
     .disablePlugins(ScalafixPlugin)
 )
-lazy val scalafixSbt1 =
-  scalafixSbt(scala212, sbt1, _.dependsOn(testUtils212 % Test))
-lazy val scalafixSbt013 =
-  scalafixSbt(scala210, sbt013, _.dependsOn(testUtils210 % Test))
+lazy val scalafixSbt1 = scalafixSbt(
+  scala212,
+  sbt1,
+  _.dependsOn(testUtils212 % Test)
+)
+lazy val scalafixSbt013 = scalafixSbt(
+  scala210,
+  sbt013,
+  _.settings(
+    scalacOptions -= warnUnusedImports
+  ).dependsOn(testUtils210 % Test)
+)
 
 val testUtils = MultiScalaProject(
   "test-utils",
@@ -221,7 +229,12 @@ val testUtils = MultiScalaProject(
     )
   )
 )
-lazy val testUtils210 = testUtils(scala210)
+lazy val testUtils210 = testUtils(
+  scala210,
+  _.settings(
+    scalacOptions -= warnUnusedImports
+  )
+)
 lazy val testUtils211 = testUtils(scala211)
 lazy val testUtils212 = testUtils(scala212)
 
@@ -259,10 +272,13 @@ val testsInput = TestProject(
     project.settings(
       noPublish,
       semanticdbSettings,
-      scalacOptions += {
-        val sourceroot = baseDirectory.in(ThisBuild).value / srcMain
-        s"-P:semanticdb:sourceroot:$sourceroot"
-      },
+      scalacOptions ++= List(
+        {
+          val sourceroot = baseDirectory.in(ThisBuild).value / srcMain
+          s"-P:semanticdb:sourceroot:$sourceroot"
+        },
+        s"-P:semanticdb:denotations:all"
+      ),
       scalacOptions ~= (_.filterNot(_ == "-Yno-adapted-args")),
       scalacOptions += "-Ywarn-adapted-args", // For NoAutoTupling
       scalacOptions += "-Ywarn-unused-import", // For RemoveUnusedImports
@@ -325,8 +341,8 @@ def unit(
         javaOptions := Nil,
         buildInfoPackage := "scalafix.tests",
         buildInfoObject := "BuildInfo",
-        sources.in(Test) += (baseDirectory
-          .in(ThisBuild))
+        sources.in(Test) += baseDirectory
+          .in(ThisBuild)
           .value / "scalafix-sbt" / "src" / "main" / "scala" / "scalafix" / "internal" / "sbt" / "ScalafixJarFetcher.scala",
         libraryDependencies ++= coursierDeps ++ testsDeps
       ).enablePlugins(BuildInfoPlugin)

project/Dependencies.scala

@@ -3,7 +3,7 @@ import org.scalajs.sbtplugin.ScalaJSPlugin.autoImport._
 /* scalafmt: { maxColumn = 120 }*/
 
 object Dependencies {
-  val scalametaV = "3.3.1"
+  val scalametaV = "3.7.0"
   val metaconfigV = "0.6.0-RC1"
   def dotty = "0.1.1-bin-20170530-f8f52cc-NIGHTLY"
   def scala210 = "2.10.6"
@@ -26,6 +26,7 @@ object Dependencies {
   def ammonite = "com.lihaoyi" %% "ammonite-ops" % "0.9.0"
   def googleDiff = "com.googlecode.java-diff-utils" % "diffutils" % "1.3.0"
 
+  def metacp = "org.scalameta" %% "metacp" % scalametaV
   def scalameta = Def.setting("org.scalameta" %%% "contrib" % scalametaV)
   val scalatest = "org.scalatest" %% "scalatest" % "3.0.0"
 

project/ScalafixBuild.scala

@@ -39,7 +39,7 @@ object ScalafixBuild extends AutoPlugin with GhpagesKeys {
     )
     lazy val warnUnusedImports = "-Ywarn-unused-import"
     lazy val compilerOptions = Seq(
-      "-Xlint",
+      warnUnusedImports,
       "-deprecation",
       "-encoding",
       "UTF-8",

scalafix-cli/src/main/scala/scalafix/cli/CliRunner.scala

@@ -13,7 +13,6 @@ import java.util.concurrent.atomic.AtomicReference
 import java.util.function.UnaryOperator
 import java.util.regex.Pattern
 import java.util.regex.PatternSyntaxException
-
 import scala.meta._
 import scala.meta.inputs.Input
 import scala.meta.internal.inputs._
@@ -42,6 +41,7 @@ import scalafix.syntax._
 import metaconfig.Configured.Ok
 import metaconfig._
 import metaconfig.ConfError
+import scalafix.internal.cli.ClasspathOps
 
 sealed abstract case class CliRunner(
     sourceroot: AbsolutePath,
@@ -89,7 +89,11 @@ sealed abstract case class CliRunner(
       val code = exitCode.get()
       if (config.lint.reporter.hasErrors) {
         ExitStatus.merge(ExitStatus.LinterError, code)
-      } else code
+      } else if (config.reporter.hasErrors) {
+        ExitStatus.merge(ExitStatus.UnexpectedError, code)
+      } else {
+        code
+      }
     }
     display.completedTask(msg, exit == ExitStatus.Ok)
     display.stop()
@@ -315,8 +319,8 @@ object CliRunner {
         .map(path => AbsolutePath(path)(common.workingPath))
         .toList
 
-    def resolveClasspath: Configured[Classpath] =
-      classpath match {
+    def resolveClasspath: Configured[Classpath] = {
+      classDirectory match {
         case Some(cp) =>
           val paths = toClasspath(cp)
           Ok(Classpath(paths))
@@ -336,6 +340,7 @@ object CliRunner {
               .notOk
           }
       }
+    }
 
     val resolvedSourceroot: Configured[AbsolutePath] = {
       val result = sourceroot
@@ -357,9 +362,17 @@ object CliRunner {
       val result: Configured[SemanticdbIndex] = cachedDatabase.getOrElse {
         (resolveClasspath |@| resolvedSourceroot).andThen {
           case (classpath, root) =>
-            val patched = Database.load(classpath, Sourcepath(root))
-            val db =
-              EagerInMemorySemanticdbIndex(patched, Sourcepath(root), classpath)
+            val index = Database.load(classpath, Sourcepath(root))
+            val deps = dependencyClasspath.map(toClasspath).getOrElse(Nil)
+            val symbolTable = ClasspathOps.newSymbolTable(
+              Classpath(classpath.shallow ++ deps),
+              common.out)
+            val db = EagerInMemorySemanticdbIndex(
+              index,
+              Sourcepath(root),
+              classpath,
+              symbolTable
+            )
             if (verbose) {
               common.err.println(
                 s"Loaded database with ${db.documents.length} documents.")

scalafix-cli/src/main/scala/scalafix/internal/cli/ClasspathOps.scala

@@ -1,8 +1,41 @@
 package scalafix.internal.cli
 
 import java.io.File
+import java.io.PrintStream
+import scala.meta.Classpath
+import scala.meta.metacp
+import scalafix.internal.util.LazySymbolTable
+import scalafix.internal.util.SymbolTable
 
 object ClasspathOps {
+
+  def bootClasspath: Option[Classpath] = sys.props.collectFirst {
+    case (k, v) if k.endsWith(".boot.class.path") => Classpath(v)
+  }
+
+  /**
+    * Process classpath with metacp to build semanticdbs of global symbols.
+    *
+    * @param sclasspath Regular classpath to process.
+    * @param out The output stream to print out error messages.
+    */
+  def toMetaClasspath(sclasspath: Classpath, out: PrintStream): Classpath = {
+    val withJDK = Classpath(
+      bootClasspath.fold(sclasspath.shallow)(_.shallow ::: sclasspath.shallow))
+    val settings = metacp
+      .Settings()
+      .withClasspath(withJDK)
+      .withScalaLibrarySynthetics(true)
+    val reporter = metacp.Reporter().withOut(out)
+    val mclasspath = scala.meta.cli.Metacp.process(settings, reporter).get
+    mclasspath
+  }
+
+  def newSymbolTable(classpath: Classpath, out: PrintStream): SymbolTable = {
+    val mclasspath = toMetaClasspath(classpath, out)
+    new LazySymbolTable(mclasspath)
+  }
+
   def getCurrentClasspath: String = {
     Thread.currentThread.getContextClassLoader match {
       case url: java.net.URLClassLoader =>

scalafix-cli/src/main/scala/scalafix/internal/cli/ScalafixOptions.scala

@@ -55,12 +55,20 @@ case class ScalafixOptions(
     sourceroot: Option[String] = None,
     @HelpMessage(
       "java.io.File.pathSeparator separated list of directories or jars containing " +
-        "'.semanticdb' files. The 'semanticdb' files are emitted by the " +
+        "'.semanticdb' files. SemanticDB files are emitted by the " +
         "semanticdb-scalac compiler plugin and are necessary for semantic rules " +
         "like ExplicitResultTypes to function."
     )
     @ValueDescription("entry1.jar:entry2.jar:target/scala-2.12/classes/")
-    classpath: Option[String] = None,
+    @ExtraName("classpath")
+    classDirectory: Option[String] = None,
+    @HelpMessage(
+      "java.io.File.pathSeparator separated list of directories or jars for dependencies. " +
+        "Does not need to contain SemanticDB files. " +
+        "Required for semantic rules like ExplicitResultTypes to work."
+    )
+    @ValueDescription("entry1.jar:entry2.jar:target/scala-2.12/classes/")
+    dependencyClasspath: Option[String] = None,
     @HelpMessage(
       "Automatically infer --classpath starting from these directories. " +
         "Ignored if --classpath is provided.")

scalafix-core/shared/src/main/scala/scala/meta/internal/scalafix/ScalafixScalametaHacks.scala

@@ -3,8 +3,12 @@ package scala.meta.internal.scalafix
 import scala.meta.Dialect
 import scala.meta.Tree
 import scala.meta.internal.trees.Origin
+import scala.meta.dialects
 
 object ScalafixScalametaHacks {
-  def dialect(language: String): Dialect = Dialect.standards(language)
+  def dialect(language: String): Dialect =
+    if (language == "Scala") dialects.Scala212
+    else if (language.isEmpty) dialects.Scala212
+    else Dialect.standards(language)
   def resetOrigin(tree: Tree): Tree = tree.withOrigin(Origin.None)
 }

scalafix-core/shared/src/main/scala/scalafix/internal/rule/ExplicitResultTypes.scala

@@ -17,6 +17,7 @@ import scalafix.syntax._
 import scalafix.util.TokenOps
 import metaconfig.Conf
 import metaconfig.Configured
+import org.langmeta.internal.semanticdb.XtensionDenotationsInternal
 
 case class ExplicitResultTypes(
     index: SemanticdbIndex,
@@ -74,9 +75,16 @@ case class ExplicitResultTypes(
     def defnType(defn: Defn): Option[(Type, Patch)] =
       for {
         name <- defnName(defn)
-        symbol <- name.symbol
-        typ <- symbol.resultType
-      } yield TypeSyntax.prettify(typ, ctx, config.unsafeShortenNames)
+        denot <- name.denotation
+        tpe <- denot.tpeInternal
+        // Skip existential types for now since they cause problems.
+        if !tpe.tag.isExistentialType
+        result <- TypeSyntax.prettify(
+          tpe,
+          ctx,
+          config.unsafeShortenNames,
+          name.pos)
+      } yield result
     import scala.meta._
     def fix(defn: Defn, body: Term): Patch = {
       val lst = ctx.tokenList

scalafix-core/shared/src/main/scala/scalafix/internal/util/CombinedSymbolTable.scala

@@ -0,0 +1,37 @@
+package scalafix.internal.util
+
+import org.langmeta.semanticdb.Symbol
+import scala.meta.Denotation
+import scalafix.SemanticdbIndex
+import org.langmeta.internal.semanticdb._
+import scala.meta.internal.{semanticdb3 => s}
+
+/**
+  * Combination of a SymbolTable and SemanticdbIndex.
+  *
+  * This utility is necessary because SymbolTable contains only global symbols and
+  * SemanticdbIndex has local symbols.
+  */
+class CombinedSymbolTable(index: SemanticdbIndex, table: SymbolTable) {
+  private def denotationToSymbolInformation(
+      symbol: String,
+      denot: Denotation): s.SymbolInformation = {
+    s.SymbolInformation(
+      symbol = symbol,
+      language = s.Language.SCALA,
+      kind = s.SymbolInformation.Kind.fromValue(denot.skind.value),
+      properties = denot.sproperties,
+      name = denot.name,
+      tpe = denot.tpeInternal
+    )
+  }
+  def info(symbol: String): s.SymbolInformation =
+    table.info(symbol).getOrElse {
+      denotationToSymbolInformation(
+        symbol,
+        index
+          .denotation(Symbol(symbol))
+          .getOrElse(throw new NoSuchElementException(symbol))
+      )
+    }
+}

scalafix-core/shared/src/main/scala/scalafix/internal/util/EagerInMemorySemanticdbIndex.scala

@@ -1,25 +1,40 @@
 package scalafix
 package internal.util
 
+import scala.collection.mutable
 import scala.meta._
+import scala.{meta => m}
 
 case class EagerInMemorySemanticdbIndex(
     database: Database,
     sourcepath: Sourcepath,
-    classpath: Classpath)
-    extends SemanticdbIndex {
+    classpath: Classpath,
+    table: SymbolTable = SymbolTable.empty
+) extends SemanticdbIndex {
   override def toString: String =
     s"$productPrefix($sourcepath, $classpath, database.size=${database.documents.length})"
   override def hashCode(): Int = database.hashCode()
-  private lazy val _denots: Map[Symbol, Denotation] = {
-    val builder = Map.newBuilder[Symbol, Denotation]
+  private lazy val _denots: mutable.Map[Symbol, Denotation] = {
+    val builder = mutable.Map.empty[Symbol, Denotation]
     database.symbols.foreach(r => builder += (r.symbol -> r.denotation))
     builder.result()
   }
-  private lazy val _names: Map[Position, ResolvedName] = {
-    val builder = Map.newBuilder[Position, ResolvedName]
-    def add(r: ResolvedName) = {
-      builder += (r.position -> r)
+  private lazy val _names: mutable.Map[Position, ResolvedName] = {
+    val builder = mutable.Map.empty[Position, ResolvedName]
+    def add(r: ResolvedName): Unit = {
+      builder.get(r.position) match {
+        case Some(conflict) =>
+          conflict.symbol match {
+            case m.Symbol.Multi(syms) =>
+              builder(r.position) =
+                conflict.copy(symbol = m.Symbol.Multi(r.symbol :: syms))
+            case sym =>
+              builder(r.position) =
+                conflict.copy(symbol = m.Symbol.Multi(r.symbol :: sym :: Nil))
+          }
+        case _ =>
+          builder(r.position) = r
+      }
     }
     database.documents.foreach { entry =>
       entry.names.foreach(add)