Add VirtualFile / VirtualFileRef / FileConverter

This implements Zinc support for passing source code as a VirtualFile datatype.
This allows build tools to pass source files as in-memory datatype.

Another motivation for doing so is to remove machine dependence from the internal state of incremental compilation (Analysis). By making Analysis free of absolute paths, we should be able to cache the file and resume compilation from another machine.

Author: eed3si9n

.scalafmt.conf

@@ -0,0 +1,21 @@
+version = 2.3.2
+maxColumn = 100
+project.git = true
+project.excludeFilters = [ /sbt-test/, /input_sources/, /contraband-scala/ ]
+
+# http://docs.scala-lang.org/style/scaladoc.html recommends the JavaDoc style.
+# scala/scala is written that way too https://github.com/scala/scala/blob/v2.12.2/src/library/scala/Predef.scala
+docstrings = JavaDoc
+
+# This also seems more idiomatic to include whitespace in import x.{ yyy }
+spaces.inImportCurlyBraces = true
+
+# This is more idiomatic Scala.
+# http://docs.scala-lang.org/style/indentation.html#methods-with-numerous-arguments
+align.openParenCallSite = false
+align.openParenDefnSite = false
+
+# For better code clarity
+danglingParentheses = true
+
+trailingCommas = preserve

.travis.yml

@@ -10,4 +10,4 @@ env:
   - ADOPTOPENJDK=8
   - ADOPTOPENJDK=11
 
-script: sbt -Dfile.encoding=UTF8 compilerInterface/mimaReportBinaryIssues headerCheck packageBin doc
+script: sbt -Dfile.encoding=UTF8 compilerInterface/headerCheck jvmfmtCheck dummyBridge/test doc

build.sbt

@@ -1,9 +1,11 @@
+import Dependencies._
 import Util._
 
 lazy val scala212 = "2.12.10"
 
-ThisBuild / headerLicense  := Some(HeaderLicense.Custom(
-  """Scala compiler interface
+ThisBuild / headerLicense := Some(
+  HeaderLicense.Custom(
+    """Scala compiler interface
     |
     |Copyright Lightbend, Inc. and Mark Harrah
     |
@@ -13,7 +15,8 @@ ThisBuild / headerLicense  := Some(HeaderLicense.Custom(
     |See the NOTICE file distributed with this work for
     |additional information regarding copyright ownership.
     |""".stripMargin
-))
+  )
+)
 
 def commonSettings: Seq[Setting[_]] = Seq(
   Test / publishArtifact := false,
@@ -26,7 +29,7 @@ def commonSettings: Seq[Setting[_]] = Seq(
 )
 
 lazy val compilerInterfaceRoot = (project in file("."))
-  .aggregate(compilerInterface)
+  .aggregate(compilerInterface, dummyBridge)
   .settings(
     publish / skip := true,
     crossScalaVersions := Vector(),
@@ -40,11 +43,11 @@ lazy val compilerInterfaceRoot = (project in file("."))
         |                     /_/
         |welcome to the build for sbt/compiler-interface.
         |""".stripMargin +
-          (if (sys.props("java.specification.version") != "1.8")
-            s"""!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+        (if (sys.props("java.specification.version") != "1.8")
+           s"""!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
                |  Java version is ${sys.props("java.specification.version")}. We recommend 1.8.
                |!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!""".stripMargin
-          else "")
+         else "")
     },
   )
 
@@ -63,13 +66,24 @@ lazy val compilerInterface = (project in file("compiler-interface"))
     crossPaths := false,
     autoScalaLibrary := false,
     mimaPreviousArtifacts := Set(
-      "1.0.0", "1.0.1", "1.0.2", "1.0.3", "1.0.4", "1.0.5",
-      "1.1.0", "1.1.1", "1.1.2", "1.1.3",
-      "1.2.0", "1.2.1", "1.2.2",
-    ) map (version =>
-      organization.value %% moduleName.value % version
-        cross (if (crossPaths.value) CrossVersion.binary else CrossVersion.disabled)
-    ),
+      "1.0.0",
+      "1.0.1",
+      "1.0.2",
+      "1.0.3",
+      "1.0.4",
+      "1.0.5",
+      "1.1.0",
+      "1.1.1",
+      "1.1.2",
+      "1.1.3",
+      "1.2.0",
+      "1.2.1",
+      "1.2.2",
+    ) map (
+        version =>
+          organization.value %% moduleName.value % version
+            cross (if (crossPaths.value) CrossVersion.binary else CrossVersion.disabled)
+      ),
     mimaBinaryIssueFilters ++= {
       import com.typesafe.tools.mima.core._
       import com.typesafe.tools.mima.core.ProblemFilters._
@@ -85,6 +99,33 @@ lazy val compilerInterface = (project in file("compiler-interface"))
     },
   )
 
+lazy val dummyBridge = (project in file("dummy-bridge"))
+  .dependsOn(compilerInterface)
+  .settings(
+    name := "Dummy Compiler Bridge",
+    scalaVersion := "2.13.1",
+    publish / skip := true,
+    exportJars := true,
+    libraryDependencies += "org.scala-lang" % "scala-compiler" % scalaVersion.value,
+    testFrameworks += new TestFramework("verify.runner.Framework"),
+    libraryDependencies ++= Seq(verify % Test, sbtIo % Test),
+    // we need to fork because in unit tests we set usejavacp = true which means
+    // we are expecting all of our dependencies to be on classpath so Scala compiler
+    // can use them while constructing its own classpath for compilation
+    Test / fork := true,
+    // needed because we fork tests and tests are ran in parallel so we have multiple Scala
+    // compiler instances that are memory hungry
+    Test / javaOptions ++= {
+      val si = (Test / scalaInstance).value
+      val bridge = (Compile / packageBin).value
+      List(
+        "-Xmx1G",
+        "-Dtest.bridgejar=" + bridge.toString,
+        "-Dtest.sijars=" + si.allJars.toList.mkString(sys.props("path.separator"))
+      )
+    },
+  )
+
 ThisBuild / organization := "org.scala-sbt"
 ThisBuild / organizationName := "sbt"
 ThisBuild / organizationHomepage := Some(url("https://www.scala-sbt.org/"))
@@ -100,11 +141,15 @@ ThisBuild / developers := List(
 )
 
 ThisBuild / description := "a binary contract between Zinc and Scala compilers"
-ThisBuild / licenses := List("Apache-2.0" -> new URL("http://www.apache.org/licenses/LICENSE-2.0.txt"))
+ThisBuild / licenses := List(
+  "Apache-2.0" -> new URL("http://www.apache.org/licenses/LICENSE-2.0.txt")
+)
 ThisBuild / homepage := Some(url("https://github.com/sbt/compiler-interface"))
 
 // Remove all additional repository other than Maven Central from POM
-ThisBuild / pomIncludeRepository := { _ => false }
+ThisBuild / pomIncludeRepository := { _ =>
+  false
+}
 ThisBuild / publishTo := {
   val nexus = "https://oss.sonatype.org/"
   if (isSnapshot.value) Some("snapshots" at nexus + "content/repositories/snapshots")