tests: Read tool args in test files

Author: dwijnand

compiler/test/dotty/tools/vulpix/ParallelTesting.scala

@@ -441,15 +441,17 @@ trait ParallelTesting extends RunnerOrchestration { self =>
           throw e
 
     protected def compile(files0: Array[JFile], flags0: TestFlags, suppressErrors: Boolean, targetDir: JFile): TestReporter = {
-      val flags = flags0.and("-d", targetDir.getPath)
-        .withClasspath(targetDir.getPath)
-
       def flattenFiles(f: JFile): Array[JFile] =
         if (f.isDirectory) f.listFiles.flatMap(flattenFiles)
         else Array(f)
 
       val files: Array[JFile] = files0.flatMap(flattenFiles)
 
+      val flags = flags0
+        .and(toolArgsFor(files.toList.map(_.toPath))(using getCodecFromEncodingOpt(flags0)): _*)
+        .and("-d", targetDir.getPath)
+        .withClasspath(targetDir.getPath)
+
       def compileWithJavac(fs: Array[String]) = if (fs.nonEmpty) {
         val fullArgs = Array(
           "javac",
@@ -1358,6 +1360,11 @@ trait ParallelTesting extends RunnerOrchestration { self =>
     // Create a CompilationTest and let the user decide whether to execute a pos or a neg test
     new CompilationTest(targets)
   }
+
+  private def getCodecFromEncodingOpt(flags: TestFlags) =
+    flags.options.sliding(2).collectFirst {
+      case Array("-encoding", encoding) => scala.io.Codec(encoding)
+    }.getOrElse(scala.io.Codec.UTF8)
 }
 
 object ParallelTesting {

tests/neg/literals.scala

@@ -2,7 +2,7 @@ trait RejectedLiterals {
   def missingHex: Int    = { 0x }        // error: invalid literal number
 }
 /*
-// scalac: -Ywarn-octal-literal -Xfatal-warnings -deprecation
+// nsc: -Ywarn-octal-literal -Xfatal-warnings -deprecation
 trait RejectedLiterals {
 
   def missingHex: Int    = { 0x }        // line 4: was: not reported, taken as zero

tests/run/1938-2.scala

@@ -1,6 +1,6 @@
 object ProdNonEmpty {
   def _1: Int = 0
-  def _2: String = "???" // Slight variation with scalac: this test passes
+  def _2: String = "???" // Slight variation with nsc: this test passes
                          // with ??? here. I think dotty behavior is fine
                          // according to the spec given that methods involved
                          // in pattern matching should be pure.