modernize build.sbt

With lots of inspiration from the firrtl build.sbt.

build.sbt

@@ -1,90 +1,78 @@
 // SPDX-License-Identifier: Apache-2.0
 
-organization := "edu.berkeley.cs"
-name := "chiseltest"
 
-// we keep in sync with chisel version names
-version := "6.0-SNAPSHOT"
-
-scalaVersion := "2.13.10"
-
-crossScalaVersions := Seq("2.13.10")
-
-resolvers ++= Resolver.sonatypeOssRepos("snapshots")
-resolvers ++= Resolver.sonatypeOssRepos("releases")
-
-testFrameworks += new TestFramework("utest.runner.Framework")
-
-publishMavenStyle := true
-
-Test / publishArtifact := false
-pomIncludeRepository := { x => false }
-
-// scm is set by sbt-ci-release
-pomExtra := (
-  <url>http://chisel.eecs.berkeley.edu/</url>
-  <licenses>
-    <license>
-      <name>apache_v2</name>
-      <url>https://opensource.org/licenses/Apache-2.0</url>
-      <distribution>repo</distribution>
-    </license>
-  </licenses>
-<developers>
-  <developer>
-    <id>ducky64</id>
-    <name>Richard Lin</name>
-  </developer>
-</developers>
+lazy val commonSettings = Seq(
+  organization := "edu.berkeley.cs",
+  scalaVersion := "2.13.10",
+  crossScalaVersions := Seq("2.13.10"),
 )
 
-publishTo := {
-  val v = version.value
-  val nexus = "https://oss.sonatype.org/"
-  if (v.trim.endsWith("SNAPSHOT")) {
-    Some("snapshots".at(nexus + "content/repositories/snapshots"))
-  } else {
-    Some("releases".at(nexus + "service/local/staging/deploy/maven2"))
-  }
-}
+val chiselVersion = "6.0.0-M3"
+val firrtlVersion = "6.0-SNAPSHOT"
 
-// Provide a managed dependency on X if -DXVersion="" is supplied on the command line.
-val defaultVersions = Map(
-  "chisel3" -> "6.0.0-M3",
-  "firrtl" -> "6.0-SNAPSHOT"
+lazy val chiseltestSettings = Seq(
+  name := "chiseltest",
+  // we keep in sync with chisel version names
+  version := "6.0-SNAPSHOT",
+  scalacOptions := Seq(
+    "-deprecation",
+    "-feature",
+    "-language:reflectiveCalls",
+    // do not warn about firrtl imports, once the firrtl repo is removed, we will need to import the code
+    "-Wconf:cat=deprecation&msg=Importing from firrtl is deprecated:s",
+    // do not warn about firrtl deprecations
+    "-Wconf:cat=deprecation&msg=will not be supported as part of the migration to the MLIR-based FIRRTL Compiler:s"
+  ),
+  // Always target Java8 for maximum compatibility
+  javacOptions ++= Seq("-source", "1.8", "-target", "1.8"),
+  libraryDependencies ++= Seq(
+    "org.chipsalliance" %% "chisel" % chiselVersion,
+    "edu.berkeley.cs" %% "firrtl2" % firrtlVersion,
+    "org.scalatest" %% "scalatest" % "3.2.17",
+    "com.lihaoyi" %% "utest" % "0.8.1",
+    "net.java.dev.jna" % "jna" % "5.13.0",
+    "org.scala-lang" % "scala-reflect" % scalaVersion.value,
+    "com.lihaoyi" %% "os-lib" % "0.8.1",
+    compilerPlugin(("org.chipsalliance" % "chisel-plugin" % chiselVersion).cross(CrossVersion.full))
+  ),
+  resolvers ++= Resolver.sonatypeOssRepos("snapshots"),
+  resolvers ++= Resolver.sonatypeOssRepos("releases"),
+  testFrameworks += new TestFramework("utest.runner.Framework"),
 )
 
-scalacOptions ++= Seq(
-  "-language:reflectiveCalls",
-  "-deprecation",
-  "-feature",
-  "-Xcheckinit",
-  // do not warn about firrtl imports, once the firrtl repo is removed, we will need to import the code
-  "-Wconf:cat=deprecation&msg=Importing from firrtl is deprecated:s",
-  // do not warn about firrtl deprecations
-  "-Wconf:cat=deprecation&msg=will not be supported as part of the migration to the MLIR-based FIRRTL Compiler:s"
-) ++ {
-  CrossVersion.partialVersion(scalaVersion.value) match {
-    case Some((2, n)) if n >= 13 => Seq("-Ymacro-annotations")
-    case _                       => Nil
-  }
-}
+lazy val publishSettings = Seq(
+  publishMavenStyle := true,
+  Test / publishArtifact := false,
+  pomIncludeRepository := { x => false },
+  // scm is set by sbt-ci-release
+  pomExtra := (
+    <url>http://chisel.eecs.berkeley.edu/</url>
+      <licenses>
+        <license>
+          <name>apache_v2</name>
+          <url>https://opensource.org/licenses/Apache-2.0</url>
+          <distribution>repo</distribution>
+        </license>
+      </licenses>
+      <developers>
+        <developer>
+          <id>ducky64</id>
+          <name>Richard Lin</name>
+        </developer>
+      </developers>
+    ),
+  publishTo := {
+    val v = version.value
+    val nexus = "https://oss.sonatype.org/"
+    if (v.trim.endsWith("SNAPSHOT")) {
+      Some("snapshots".at(nexus + "content/repositories/snapshots"))
+    } else {
+      Some("releases".at(nexus + "service/local/staging/deploy/maven2"))
+    }
+  },
+)
 
-libraryDependencies ++= Seq(
-  "org.chipsalliance" %% "chisel" % defaultVersions("chisel3"),
-  "edu.berkeley.cs" %% "firrtl2" % defaultVersions("firrtl"),
-  "org.scalatest" %% "scalatest" % "3.2.17",
-  "com.lihaoyi" %% "utest" % "0.8.1",
-  "net.java.dev.jna" % "jna" % "5.13.0",
-  "org.scala-lang" % "scala-reflect" % scalaVersion.value,
-  "com.lihaoyi" %% "os-lib" % "0.8.1",
-  compilerPlugin(("org.chipsalliance" % "chisel-plugin" % defaultVersions("chisel3")).cross(CrossVersion.full))
-) ++ {
-  CrossVersion.partialVersion(scalaVersion.value) match {
-    case Some((2, n)) if n >= 13 => Nil
-    case _ =>
-      Seq(
-        compilerPlugin(("org.scalamacros" % "paradise" % "2.1.1").cross(CrossVersion.full))
-      )
-  }
-}
+lazy val chiseltest = (project in file("."))
+  .settings(commonSettings)
+  .settings(chiseltestSettings)
+  .settings(publishSettings)