moved getProjectRootOrCwd to Simulation object and used it in TestingDirectory

+ added CHISEL_PROJECT_ROOT as an alternative for detectig project root
+ fixed tests to work with with both relative and absolute HasTestingDirectory.getDirectory path

Author: kammoh

src/main/scala/chisel3/testing/FileCheck.scala

@@ -89,8 +89,8 @@ trait FileCheck {
       // Filecheck needs to have the thing to check in a file.
       //
       // TODO: This could be made ephemeral or use a named pipe?
-      // os.makeDir(os.RelPath(testingDirectory.getDirectory))
-      val dir = os.pwd / os.RelPath(testingDirectory.getDirectory)
+      val testingDir = os.FilePath(testingDirectory.getDirectory)
+      val dir = testingDir.resolveFrom(os.pwd)
       os.makeDir.all(dir)
       val tempDir = os.temp.dir(dir = dir, deleteOnExit = false)
       val checkFile = tempDir / "check"

src/main/scala/chisel3/testing/scalatest/WithTestingDirectory.scala

@@ -3,6 +3,7 @@
 package chisel3.testing.scalatest
 
 import chisel3.testing.HasTestingDirectory
+import svsim.Simulation
 import java.nio.file.{FileSystems, Path, Paths}
 import org.scalatest.{TestSuite, TestSuiteMixin}
 import scala.util.DynamicVariable
@@ -32,7 +33,7 @@ trait TestingDirectory extends TestSuiteMixin { self: TestSuite =>
     *
     * For different behavior, please override this in your test suite.
     */
-  def buildDir: Path = Paths.get("build", "chiselsim")
+  def buildDir: Path = Simulation.getProjectRootOrCwd.resolve("build").resolve("chiselsim")
 
   // Assemble all the directories that should be created for this test.  This is
   // done by examining the test (via a fixture) and then setting a dynamic

src/test/scala-2/chiselTests/experimental/TraceSpec.scala

@@ -26,7 +26,7 @@ class TraceSpec extends AnyFlatSpec with Matchers with TestingDirectory {
   def compile(testName: String, gen: () => Module)(
     implicit testingDirectory: HasTestingDirectory
   ): (os.Path, AnnotationSeq) = {
-    val testDir = os.pwd / os.RelPath(testingDirectory.getDirectory)
+    val testDir = os.FilePath(testingDirectory.getDirectory).resolveFrom(os.pwd)
     val annos = (new ChiselStage).execute(
       Array("--target-dir", s"$testDir", "--target", "systemverilog", "--split-verilog"),
       Seq(

src/test/scala-2/chiselTests/stage/WarningConfigurationSpec.scala

@@ -92,7 +92,7 @@ class WarningConfigurationSpec extends AnyFunSpec with Matchers with chiselTests
   }
 
   private def makeFile(name: String)(contents: String)(implicit testingDirectory: HasTestingDirectory): java.io.File = {
-    val dir = os.pwd / os.RelPath(testingDirectory.getDirectory)
+    val dir = os.FilePath(testingDirectory.getDirectory).resolveFrom(os.pwd)
     os.makeDir.all(dir)
     val file = dir / name
     os.write.over(file, contents)

svsim/src/main/scala/Simulation.scala

@@ -15,21 +15,12 @@ final class Simulation private[svsim] (
 ) {
   private val executionScriptPath = s"$workingDirectory/execution-script.txt"
 
-  protected final def getProjectRootOrCwd: Path =
-    sys.props
-      .get("chisel.project.root")
-      .orElse(sys.env.get("MILL_WORKSPACE_ROOT"))
-      .orElse(sys.env.get("PWD"))
-      .map(Paths.get("").toAbsolutePath.resolve(_))
-      .getOrElse(Paths.get(""))
-      .toAbsolutePath
-
   def workingDirectory: Path = {
     val path = Paths.get(workingDirectoryPath)
     if (path.isAbsolute) {
       path
     } else {
-      getProjectRootOrCwd.resolve(path)
+      Simulation.getProjectRootOrCwd.resolve(path)
     }
   }
 
@@ -460,4 +451,21 @@ object Simulation {
       }
     }
   }
+
+  /**
+    * Tries to detect the project root (workspace) directory based on "chisel.project.root" Java system property
+    *  as well as CHISEL_PROJECT_ROOT, MILL_WORKSPACE_ROOT (set by mill), and PWD environment variables (tried in that order).
+    * If none of those work, returns the current working directory.
+    *
+    * @return the absolute path to the project root or current working directory
+    */
+  def getProjectRootOrCwd: Path =
+    sys.props
+      .get("chisel.project.root")
+      .orElse(sys.env.get("CHISEL_PROJECT_ROOT"))
+      .orElse(sys.env.get("MILL_WORKSPACE_ROOT"))
+      .orElse(sys.env.get("PWD"))
+      .map(Paths.get("").toAbsolutePath.resolve(_))
+      .getOrElse(Paths.get(""))
+      .toAbsolutePath
 }