Improve RuleTst performance

Reuse the classloader for auxclasspath
instead of creating a new one for every
single rule test case.

pmd-java/src/test/java/net/sourceforge/pmd/lang/java/JavaParsingHelper.java

@@ -6,16 +6,8 @@ package net.sourceforge.pmd.lang.java;
 
 import static net.sourceforge.pmd.lang.ast.Parser.ParserTask;
 
-import java.io.ByteArrayInputStream;
 import java.io.IOException;
-import java.io.InputStream;
 import java.io.PrintStream;
-import java.io.UncheckedIOException;
-import java.net.URI;
-import java.nio.file.FileSystem;
-import java.nio.file.FileSystems;
-import java.nio.file.Files;
-import java.nio.file.Path;
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -29,6 +21,7 @@ import org.jetbrains.annotations.NotNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import net.sourceforge.pmd.internal.util.ClasspathClassLoader;
 import net.sourceforge.pmd.lang.LanguageProcessor;
 import net.sourceforge.pmd.lang.ast.Node;
 import net.sourceforge.pmd.lang.ast.SemanticErrorReporter;
@@ -54,32 +47,15 @@ public class JavaParsingHelper extends BaseParsingHelper<JavaParsingHelper, ASTC
      * default options of JavaParsingHelper. This allows constants like
      * the null type to be compared.
      */
-    public static final TypeSystem TEST_TYPE_SYSTEM = TypeSystem.usingClasspath(name -> {
+    public static final TypeSystem TEST_TYPE_SYSTEM;
-        ClassLoader classLoader = JavaParsingHelper.class.getClassLoader();
 
-        if (name.endsWith("/module-info.class")) {
+    static {
-            String moduleName = name.substring(0, name.length() - "/module-info.class".length());
+        try {
-
+            TEST_TYPE_SYSTEM = TypeSystem.usingClassLoaderClasspath(new ClasspathClassLoader("", JavaParsingHelper.class.getClassLoader()));
-            InputStream inputStream = null;
+        } catch (IOException e) {
-            @SuppressWarnings("PMD.CloseResource")
+            throw new RuntimeException(e);
-            // this JrtFileSystem instance can't be closed (UnsupportedOperationException),
-            // because it used by the current running JVM
-            FileSystem fs = FileSystems.getFileSystem(URI.create("jrt:/"));
-            try {
-                Path moduleInfoPath = fs.getPath("modules", moduleName, "module-info.class");
-                if (Files.exists(moduleInfoPath)) {
-                    inputStream = new ByteArrayInputStream(Files.readAllBytes(moduleInfoPath));
-                }
-            } catch (IOException e) {
-                throw new UncheckedIOException(e);
-            }
-            if (inputStream != null) {
-                return inputStream;
-            }
         }
-
+    }
-        return classLoader.getResourceAsStream(name);
-    });
 
     /** This runs all processing stages when parsing. */
     public static final JavaParsingHelper DEFAULT = new JavaParsingHelper(

pmd-test/src/main/java/net/sourceforge/pmd/test/RuleTst.java

@@ -31,6 +31,7 @@ import org.xml.sax.InputSource;
 
 import net.sourceforge.pmd.PMDConfiguration;
 import net.sourceforge.pmd.PmdAnalysis;
+import net.sourceforge.pmd.internal.util.ClasspathClassLoader;
 import net.sourceforge.pmd.lang.LanguageVersion;
 import net.sourceforge.pmd.lang.document.FileId;
 import net.sourceforge.pmd.lang.document.TextFile;
@@ -225,9 +226,10 @@ public abstract class RuleTst {
         return runTestFromString(test.getCode(), rule, test.getLanguageVersion());
     }
 
-    private static final Path PATH_TO_JRT_FS_JAR;
+    private static final ClassLoader TEST_AUXCLASSPATH_CLASSLOADER;
 
     static {
+        final Path PATH_TO_JRT_FS_JAR;
         // find jrt-fs.jar to be added to auxclasspath
         // Similar logic like jdk.internal.jrtfs.SystemImage
         CodeSource codeSource = Object.class.getProtectionDomain().getCodeSource();
@@ -244,6 +246,12 @@ public abstract class RuleTst {
                 throw new IllegalStateException(e);
             }
         }
+
+        try {
+            TEST_AUXCLASSPATH_CLASSLOADER = new ClasspathClassLoader(PATH_TO_JRT_FS_JAR.toString(), PMDConfiguration.class.getClassLoader());
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
     }
 
     /**
@@ -254,9 +262,7 @@ public abstract class RuleTst {
         configuration.setIgnoreIncrementalAnalysis(true);
         configuration.setDefaultLanguageVersion(languageVersion);
         configuration.setThreads(0); // don't use separate threads
-        configuration.prependAuxClasspath(".");
+        configuration.setClassLoader(TEST_AUXCLASSPATH_CLASSLOADER);
-        configuration.prependAuxClasspath(PATH_TO_JRT_FS_JAR.toString());
-
 
         try (PmdAnalysis pmd = PmdAnalysis.create(configuration)) {
             pmd.files().addFile(TextFile.forCharSeq(code, FileId.fromPathLikeString("file"), languageVersion));