8296645: org.openjdk.bench.javax.tools.Javac leaves class files in current directory

Reviewed-by: redestad, jpai

test/micro/org/openjdk/bench/javax/tools/Javac.java

@@ -29,13 +29,19 @@ import org.openjdk.jmh.annotations.OutputTimeUnit;
 import org.openjdk.jmh.annotations.Scope;
 import org.openjdk.jmh.annotations.Setup;
 import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.TearDown;
 
 import javax.tools.JavaCompiler;
 import javax.tools.SimpleJavaFileObject;
 import javax.tools.StandardJavaFileManager;
+import javax.tools.StandardLocation;
 import javax.tools.ToolProvider;
+import java.io.IOException;
+import java.io.File;
 import java.net.URI;
+import java.nio.file.Files;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 
@@ -46,18 +52,35 @@ public class Javac {
     private List<JavaSourceFromString> compilationUnits;
     private JavaCompiler compiler;
     private StandardJavaFileManager fileManager;
+    private File classOutputDir;
 
     @Setup
-    public void prepare() {
+    public void prepare() throws IOException {
         String helloWorld = "class Apan {   \n" + "  public static void main(String args[]) {\n"
                 + "     System.out.println(\"hej apa\");\n" + "  }\n" + "}\n";
 
         compiler = ToolProvider.getSystemJavaCompiler();
+
         fileManager = compiler.getStandardFileManager(null, null, null);
+        classOutputDir = Files.createTempDirectory(Javac.class.getName()).toFile();
+        fileManager.setLocation(StandardLocation.CLASS_OUTPUT, Collections.singleton(classOutputDir));
+
         compilationUnits = new ArrayList<>();
         compilationUnits.add(new JavaSourceFromString("Apan", helloWorld));
     }
 
+    @TearDown
+    public void tearDown() {
+        for (File f : classOutputDir.listFiles()) {
+            if (f.isFile()) {
+                f.delete();
+            } else {
+                throw new IllegalStateException("Unexpected non-file: " + f);
+            }
+        }
+        classOutputDir.delete();
+    }
+
     @Benchmark
     public Boolean testCompile() throws Exception {
         JavaCompiler.CompilationTask task = compiler.getTask(null, fileManager, null, null, null, compilationUnits);