Merge branch '2.13.x' into specification-pdf-wkhtmltopdf-katex

CONTRIBUTING.md

@@ -36,7 +36,9 @@ The kind of code we can accept depends on the life cycle for the release you're
 
 #### Bug Fix
 
-At the end of the commit message, include "Fixes scala/bug#NNNN", where https://github.com/scala/bug/issues/NNNN tracks the bug you're fixing. We also recommend naming your branch after the ticket number.
+At the end of the PR description, which is autofilled with the commit message if there is only one commit, add the phrase, "Fixes scala/bug#NNNN", where `https://github.com/scala/bug/issues/NNNN` tracks the bug you're fixing. Github will turn your bug number into a link.
+
+We also recommend naming your branch after the ticket number.
 
 Please make sure the ticket's milestone corresponds to the upcoming milestone for the branch your PR targets. The CI automation will automatically assign the milestone after you open the PR.
 
@@ -79,7 +81,11 @@ root> junit/testQuick
 
 It might take a few minutes the first time you run `junit/testQuick`, but from the second time onwards
 sbt will only run the tests that is affected by the code change since the last run.
-See `test/junit/` for the examples of JUnit tests.
+See `test/junit/` for examples of JUnit tests.
+
+JUnit tests will be compiled with the `starr` compiler, and run against the `quick` library. Some JUnit tests (search for `BytecodeTest`) invoke the compiler programmatically and test its behavior or output, these tests use the `quick` compiler. 
+
+`starr` is the Scala release used to build the compiler and library, usually the last release. `quick` is the result of that compilation. See also ["Build Setup"](https://github.com/scala/scala#build-setup) in the README.
 
 #### ScalaCheck
 
@@ -109,8 +115,14 @@ To run a single negative test from sbt shell:
 root> partest --verbose test/files/neg/delayed-init-ref.scala
 ```
 
-To specify specific flags such as `-deprecation -Xlint -Xfatal-warnings`, you can put them in
-`test/files/neg/<test>.flags`. This could be used to test specific behavior under `-deprecation` flag etc.
+To specify compiler flags such as `-deprecation -Xlint -Xfatal-warnings`, you can add a comment
+at the top of your source file of the form: `// scalac: -deprecation -Xlint -Xfatal-warnings`.
+
+To test that no warnings are emitted, use `-Xfatal-warnings`. That will fail a `pos` test if there
+are warnings. Note that `pos` tests do not have `.check` files.
+
+To test that warnings are correctly emitted, use `-Xfatal-warnings` with a `neg` test and `.check` file.
+The usual way to create a `.check` file is `partest --update-check`.
 
 To run all tests in `neg` categories from sbt shell:
 
@@ -147,8 +159,11 @@ See `--help` for more info:
 root> partest --help
 ```
 
-If you're fixing a bug in the compiler, you would typically start with Partest;
-If you're fixing a bug or implementing new features in the library, consider using JUnit and/or ScalaCheck.
+Partests are compiled by the `quick` compiler (and `run` partests executed with the `quick` library),
+and therefore:
+
+* if you're working on the compiler, you must write a partest, or a `BytecodeTest` JUnit test which invokes the compiler programmatically; however
+* if you're working on the library, a JUnit and/or ScalaCheck is better.
 
 #### exploring with REPL
 
@@ -206,7 +221,9 @@ by the commit on the code base, so use the active voice and the
 present tense.  That also makes the commit subjects easy to reuse in
 release notes.
 
-For a bugfix, the end of the commit message should say "Fixes scala/bug#NNNN".
+For a bugfix, the end of the PR description (that is, the first comment on the PR) should say, "Fixes scala/bug#NNNN", as mentioned above.
+
+NOTE: it's best not to add the issue reference to your commit message, as github will pollute the conversation on the ticket with notifications every time you commit.
 
 If a commit purely refactors and is not intended to change behaviour,
 say so.

build.sbt

@@ -40,9 +40,9 @@ import VersionUtil._
 import scala.tools.nsc.util.ScalaClassLoader.URLClassLoader
 
 // Non-Scala dependencies:
-val junitDep          = "junit"                          % "junit"                            % "4.11"
+val junitDep          = "junit"                          % "junit"                            % "4.12"
 val junitInterfaceDep = "com.novocode"                   % "junit-interface"                  % "0.11"                            % "test"
-val jolDep            = "org.openjdk.jol"                % "jol-core"                         % "0.5"
+val jolDep            = "org.openjdk.jol"                % "jol-core"                         % "0.9"
 val asmDep            = "org.scala-lang.modules"         % "scala-asm"                        % versionProps("scala-asm.version")
 val jlineDep          = "jline"                          % "jline"                            % versionProps("jline.version")
 val testInterfaceDep  = "org.scala-sbt"                  % "test-interface"                   % "1.0"
@@ -151,6 +151,7 @@ lazy val commonSettings = instanceSettings ++ clearSourceAndResourceDirectories
   cleanFiles += (classDirectory in Compile).value,
   cleanFiles += (target in Compile in doc).value,
   fork in run := true,
+  connectInput in run := true,
   //scalacOptions in Compile += "-Xlint:-nullary-override,-inaccessible,-nonlocal-return,_",
   //scalacOptions ++= Seq("-Xmaxerrs", "5", "-Xmaxwarns", "5"),
   scalacOptions in Compile in doc ++= Seq(
@@ -161,7 +162,7 @@ lazy val commonSettings = instanceSettings ++ clearSourceAndResourceDirectories
     "-doc-version", versionProperties.value.canonicalVersion,
     "-doc-title", description.value,
     "-sourcepath", (baseDirectory in ThisBuild).value.toString,
-    "-doc-source-url", s"https://github.com/scala/scala/tree/${versionProperties.value.githubTree}€{FILE_PATH}.scala#L1"
+    "-doc-source-url", s"https://github.com/scala/scala/tree/${versionProperties.value.githubTree}€{FILE_PATH_EXT}#L€{FILE_LINE}"
   ),
   //maxErrors := 10,
   setIncOptions,
@@ -361,8 +362,7 @@ lazy val library = configureAsSubproject(project)
     mimaPreviousArtifacts := mimaReferenceVersion.value.map(organization.value % name.value % _).toSet,
     mimaCheckDirection := "both"
   )
-  .settings(filterDocSources("*.scala" -- (regexFileFilter(".*/runtime/.*\\$\\.scala") ||
-                                           regexFileFilter(".*/runtime/ScalaRunTime\\.scala"))))
+  .settings(filterDocSources("*.scala" -- regexFileFilter(".*/scala/runtime/.*")))
 
 lazy val reflect = configureAsSubproject(project)
   .settings(generatePropertiesFileSettings)
@@ -397,12 +397,12 @@ lazy val compilerOptionsExporter = Project("compilerOptionsExporter", file(".")
   .settings(disablePublishing)
   .settings(
     libraryDependencies ++= Seq(
-      "com.fasterxml.jackson.core" % "jackson-core" % "2.9.5",
-      "com.fasterxml.jackson.core" % "jackson-annotations" % "2.9.5",
-      "com.fasterxml.jackson.core" % "jackson-databind" % "2.9.5",
-      "com.fasterxml.jackson.dataformat" % "jackson-dataformat-yaml" % "2.9.5"
+      "com.fasterxml.jackson.core" % "jackson-core" % "2.9.7",
+      "com.fasterxml.jackson.core" % "jackson-annotations" % "2.9.7",
+      "com.fasterxml.jackson.core" % "jackson-databind" % "2.9.7",
+      "com.fasterxml.jackson.dataformat" % "jackson-dataformat-yaml" % "2.9.7"
       // TODO: implement without Scala dependency. Not available when STARR has a new binary verison.
-      // "com.fasterxml.jackson.module" %% "jackson-module-scala" % "2.9.5"
+      // "com.fasterxml.jackson.module" %% "jackson-module-scala" % "2.9.7"
     )
   )
 
@@ -425,7 +425,7 @@ lazy val compiler = configureAsSubproject(project)
     // (with strings) to deal with mutual recursion
     products in Compile in packageBin :=
       (products in Compile in packageBin).value ++
-        Seq((dependencyClasspath in Compile).value.find(_.get(moduleID.key) == Some(asmDep)).get.data) ++
+        Seq((dependencyClasspath in Compile).value.find(_.get(moduleID.key).map(id => (id.organization, id.name, id.revision)).contains((asmDep.organization, asmDep.name, asmDep.revision))).get.data) ++
         (products in Compile in packageBin in LocalProject("interactive")).value ++
         (products in Compile in packageBin in LocalProject("scaladoc")).value ++
         (products in Compile in packageBin in LocalProject("repl")).value ++

project/GenerateAnyVals.scala

@@ -147,7 +147,7 @@ import scala.language.implicitConversions"""
     def mkCoercions = numeric map (x => "def to%s: %s".format(x, x))
     def mkUnaryOps  = unaryOps map (x => "%s\n  def unary_%s : %s".format(x.doc, x.op, this opType I))
     def mkStringOps = List(
-      """@deprecated("Adding a number and a String is deprecated. Use the string interpolation `s\"$num$str\"`", "2.13.0") def +(x: String): String"""
+      "@deprecated(\"Adding a number and a String is deprecated. Use the string interpolation `s\\\"$num$str\\\"`\", \"2.13.0\")\n  def +(x: String): String"
     )
     def mkShiftOps  = (
       for (op <- shiftOps ; arg <- List(I, L)) yield {

project/ScalaOptionParser.scala

@@ -82,7 +82,7 @@ object ScalaOptionParser {
   }
 
   // TODO retrieve this data programmatically, ala https://github.com/scala/scala-tool-support/blob/master/bash-completion/src/main/scala/BashCompletion.scala
-  private def booleanSettingNames = List("-X", "-Xcheckinit", "-Xdev", "-Xdisable-assertions", "-Xexperimental", "-Xfatal-warnings", "-Xfuture", "-Xlog-free-terms", "-Xlog-free-types", "-Xlog-implicit-conversions", "-Xlog-implicits", "-Xlog-reflective-calls",
+  private def booleanSettingNames = List("-X", "-Xcheckinit", "-Xdev", "-Xdisable-assertions", "-Xexperimental", "-Xfatal-warnings", "-Xlog-free-terms", "-Xlog-free-types", "-Xlog-implicit-conversions", "-Xlog-implicits", "-Xlog-reflective-calls",
     "-Xno-forwarders", "-Xno-patmat-analysis", "-Xno-uescape", "-Xnojline", "-Xprint-pos", "-Xprint-types", "-Xprompt", "-Xresident", "-Xshow-phases", "-Xverify", "-Y",
     "-Ybreak-cycles", "-Ydebug", "-Ycompact-trees", "-YdisableFlatCpCaching", "-Ydoc-debug",
     "-Yide-debug",

project/VersionUtil.scala

@@ -33,7 +33,7 @@ object VersionUtil {
       |    / __/ __// _ | / /  / _ |
       |  __\ \/ /__/ __ |/ /__/ __ |
       | /____/\___/_/ |_/____/_/ | |
-      |                          |/  %s""".stripMargin.linesIterator.drop(1).map(s => s"${ "%n" }${ s }").mkString,
+      |                          |/  %s""".stripMargin.linesIterator.mkString("%n"),
     resourceGenerators in Compile += generateVersionPropertiesFile.map(file => Seq(file)).taskValue,
     generateVersionPropertiesFile := generateVersionPropertiesFileImpl.value
   )

project/build.properties

@@ -1 +1 @@
-sbt.version=1.2.3
+sbt.version=1.2.7

scripts/common

@@ -11,7 +11,7 @@ else
 fi
 
 SBT_CMD=${SBT_CMD-sbt}
-SBT_CMD="$SBT_CMD -sbt-version 1.2.3"
+SBT_CMD="$SBT_CMD -sbt-version 1.2.7"
 
 # repo to publish builds
 integrationRepoUrl=${integrationRepoUrl-"https://scala-ci.typesafe.com/artifactory/scala-integration/"}

spec/01-lexical-syntax.md

@@ -333,14 +333,16 @@ digit           ::=  ‘0’ | nonZeroDigit
 nonZeroDigit    ::=  ‘1’ | … | ‘9’
 ```
 
-Integer literals are usually of type `Int`, or of type
-`Long` when followed by a `L` or
-`l` suffix. Values of type `Int` are all integer
+Values of type `Int` are all integer
 numbers between ´-2\^{31}´ and ´2\^{31}-1´, inclusive.  Values of
 type `Long` are all integer numbers between ´-2\^{63}´ and
 ´2\^{63}-1´, inclusive. A compile-time error occurs if an integer literal
 denotes a number outside these ranges.
 
+Integer literals are usually of type `Int`, or of type
+`Long` when followed by a `L` or `l` suffix.
+(Lowercase `l` is deprecated for reasons of legibility.)
+
 However, if the expected type [_pt_](06-expressions.html#expression-typing) of a literal
 in an expression is either `Byte`, `Short`, or `Char`
 and the integer number fits in the numeric range defined by the type,
@@ -353,8 +355,11 @@ is _pt_. The numeric ranges given by these types are:
 |`Short`         | ´-2\^{15}´ to ´2\^{15}-1´|
 |`Char`          | ´0´ to ´2\^{16}-1´       |
 
+The digits of a numeric literal may be separated by
+arbitrarily many underscores for purposes of legibility.
+
 > ```scala
-> 0          21          0xFFFFFFFF       -42L
+> 0           21_000      0x7F        -42L        0xFFFF_FFFF
 > ```
 
 ### Floating Point Literals

spec/05-classes-and-objects.md

@@ -63,14 +63,15 @@ The _least proper supertype_ of a template is the class type or
 class types.
 
 The statement sequence ´\mathit{stats}´ contains member definitions that
-define new members or overwrite members in the parent classes.  If the
-template forms part of an abstract class or trait definition, the
-statement part ´\mathit{stats}´ may also contain declarations of abstract
-members. If the template forms part of a concrete class definition,
+define new members or override members in the parent classes.  If the
+template forms part of an abstract class or trait definition, then
+´\mathit{stats}´ may also contain declarations of abstract members.
+If the template forms part of a concrete class definition,
 ´\mathit{stats}´ may still contain declarations of abstract type members, but
 not of abstract term members.  Furthermore, ´\mathit{stats}´ may in any case
-also contain expressions; these are executed in the order they are
-given as part of the initialization of a template.
+also contain strictly evaluated expressions: these are executed in the order they are
+given as part of the initialization of a template, even if they appear in
+the definition of overridden members.
 
 The sequence of template statements may be prefixed with a formal
 parameter definition and an arrow, e.g. `´x´ =>`, or

spec/06-expressions.md

@@ -931,7 +931,8 @@ be implemented in different ways for different carrier types.
 
 The translation scheme is as follows.  In a first step, every
 generator `´p´ <- ´e´`, where ´p´ is not [irrefutable](08-pattern-matching.html#patterns)
-for the type of ´e´ is replaced by
+for the type of ´e´, and ´p´ is some pattern other than a simple name
+or a name followed by a colon and a type, is replaced by
 
 ```scala
 ´p´ <- ´e´.withFilter { case ´p´ => true; case _ => false }
@@ -1270,7 +1271,7 @@ include at least the expressions of the following forms:
 
 ```ebnf
 BlockStat    ::=  Import
-               |  {Annotation} [‘implicit’ | ‘lazy’] Def
+               |  {Annotation} [‘implicit’] [‘lazy’] Def
                |  {Annotation} {LocalModifier} TmplDef
                |  Expr1
                |
@@ -1396,16 +1397,16 @@ type ´T´ by evaluating the expression to which ´m´ is bound.
 If the method takes only implicit parameters, implicit
 arguments are passed following the rules [here](07-implicits.html#implicit-parameters).
 
+###### Empty Application
+Otherwise, if ´e´ has method type ´()T´, it is implicitly applied to the empty
+argument list, yielding ´e()´.
+
 ###### Eta Expansion
 Otherwise, if the method is not a constructor,
-and the expected type ´\mathit{pt}´ is a function type
+and the expected type ´\mathit{pt}´ is a function type (potentially after sam conversion)
 ´(\mathit{Ts}') \Rightarrow T'´, [eta-expansion](#eta-expansion)
 is performed on the expression ´e´.
 
-###### Empty Application
-Otherwise, if ´e´ has method type ´()T´, it is implicitly applied to the empty
-argument list, yielding ´e()´.
-
 ### Overloading Resolution
 
 If an identifier or selection ´e´ references several members of a

spec/09-top-level-definitions.md

@@ -123,8 +123,14 @@ Like all other references, package references are relative. That is,
 a package reference starting in a name ´p´ will be looked up in the
 closest enclosing scope that defines a member named ´p´.
 
-The special predefined name `_root_` refers to the
-outermost root package which contains all top-level packages.
+If a package name is shadowed, it's possible to refer to its
+fully-qualified name by prefixing it with
+the special predefined name `_root_`, which refers to the
+outermost root package that contains all top-level packages.
+
+The name `_root_` has this special denotation only when
+used as the first element of a qualifier; it is an ordinary
+identifier otherwise.
 
 ###### Example
 Consider the following program:
@@ -134,11 +140,18 @@ package b {
   class B
 }
 
-package a.b {
-  class A {
-    val x = new _root_.b.B
+package a {
+  package b {
+    class A {
+      val x = new _root_.b.B
+    }
+    class C {
+      import _root_.b._
+      def y = new B
+    }
   }
 }
+
 ```
 
 Here, the reference `_root_.b.B` refers to class `B` in the