From c39f06a84c5aaf17efbaf09f0496d2e8640e4e37 Mon Sep 17 00:00:00 2001
From: Uwe Schindler <uwe@thetaphi.de>
Date: Sat, 24 Sep 2022 13:33:15 +0200
Subject: [PATCH 1/2] Add DEBUG level logging and report classpath and JDK type
 to allow debugging od classpath/JDK related problems. This closes #202

---
 .../de/thetaphi/forbiddenapis/Checker.java    | 19 +++++++++++++++----
 .../de/thetaphi/forbiddenapis/Logger.java     |  1 +
 .../forbiddenapis/RelatedClassLookup.java     |  1 +
 .../de/thetaphi/forbiddenapis/Signatures.java |  6 ++++++
 .../thetaphi/forbiddenapis/StdIoLogger.java   |  5 +++++
 .../thetaphi/forbiddenapis/ant/AntTask.java   |  7 ++++++-
 .../thetaphi/forbiddenapis/cli/CliMain.java   |  8 +++++++-
 .../gradle/CheckForbiddenApis.java            | 12 +++++++++++-
 .../maven/AbstractCheckMojo.java              | 12 +++++++++++-
 .../forbiddenapis/CheckerSetupTest.java       |  4 ++--
 10 files changed, 65 insertions(+), 10 deletions(-)

diff --git a/src/main/java/de/thetaphi/forbiddenapis/Checker.java b/src/main/java/de/thetaphi/forbiddenapis/Checker.java
index 3992c3b2..9204f904 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/Checker.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/Checker.java
@@ -66,6 +66,7 @@ public static enum Option {
   final Logger logger;
   
   final ClassLoader loader;
+  final String humanClasspath;
   final java.lang.reflect.Method method_Class_getModule, method_Module_getName;
   final EnumSet<Option> options;
   
@@ -79,13 +80,14 @@ public static enum Option {
   /** descriptors (not internal names) of all annotations that suppress */
   final Set<String> suppressAnnotations = new LinkedHashSet<>();
     
-  public Checker(Logger logger, ClassLoader loader, Option... options) {
-    this(logger, loader, (options.length == 0) ? EnumSet.noneOf(Option.class) : EnumSet.copyOf(Arrays.asList(options)));
+  public Checker(Logger logger, ClassLoader loader, String humanClasspath, Option... options) {
+    this(logger, loader, humanClasspath, (options.length == 0) ? EnumSet.noneOf(Option.class) : EnumSet.copyOf(Arrays.asList(options)));
   }
   
-  public Checker(Logger logger, ClassLoader loader, EnumSet<Option> options) {
+  public Checker(Logger logger, ClassLoader loader, String humanClasspath, EnumSet<Option> options) {
     this.logger = logger;
     this.loader = loader;
+    this.humanClasspath = (humanClasspath == null || humanClasspath.isEmpty()) ? null : humanClasspath;
     this.options = options;
     this.start = System.currentTimeMillis();
     
@@ -101,6 +103,7 @@ public Checker(Logger logger, ClassLoader loader, EnumSet<Option> options) {
       method_Module_getName = method_Class_getModule
           .getReturnType().getMethod("getName");
       isSupportedJDK = true;
+      logger.debug("Detected Java 9 or later with module system.");
     } catch (NoSuchMethodException e) {
       method_Class_getModule = method_Module_getName = null;
     }
@@ -116,6 +119,7 @@ public Checker(Logger logger, ClassLoader loader, EnumSet<Option> options) {
         if (objectClassURL != null && "jrt".equalsIgnoreCase(objectClassURL.getProtocol())) {
           // this is Java 9+ allowing direct access to .class file resources - we do not need to deal with modules!
           isSupportedJDK = true;
+          logger.debug("Detected Java 9 or later with JRT file system.");
         } else {
           String javaHome = System.getProperty("java.home");
           if (javaHome != null) {
@@ -146,7 +150,9 @@ public Checker(Logger logger, ClassLoader loader, EnumSet<Option> options) {
             }
           }
           isSupportedJDK = !runtimePaths.isEmpty();
-          if (!isSupportedJDK) {
+          if (isSupportedJDK) {
+            logger.debug("Detected classical classpath-based JDK @ " + runtimePaths);
+          } else {
             logger.warn("Boot classpath appears to be empty or ${java.home} not defined; marking runtime as not suppported.");
           }
         }
@@ -317,6 +323,11 @@ public ClassMetadata lookupRelatedClass(String internalName, String internalName
     }
   }
   
+  @Override
+  public String getHumanClasspath() {
+    return humanClasspath;
+  }
+  
   /** Reads a list of bundled API signatures from classpath. */
   public void addBundledSignatures(String name, String jdkTargetVersion) throws IOException,ParseException {
     forbiddenSignatures.addBundledSignatures(name, jdkTargetVersion);
diff --git a/src/main/java/de/thetaphi/forbiddenapis/Logger.java b/src/main/java/de/thetaphi/forbiddenapis/Logger.java
index 0a17468a..40110d5e 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/Logger.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/Logger.java
@@ -20,4 +20,5 @@ public interface Logger {
   void error(String msg);
   void warn(String msg);
   void info(String msg);
+  void debug(String msg);
 }
diff --git a/src/main/java/de/thetaphi/forbiddenapis/RelatedClassLookup.java b/src/main/java/de/thetaphi/forbiddenapis/RelatedClassLookup.java
index d167b055..42e8463a 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/RelatedClassLookup.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/RelatedClassLookup.java
@@ -21,4 +21,5 @@
 public interface RelatedClassLookup {
   ClassMetadata lookupRelatedClass(String internalName, String internalNameOrig);
   ClassMetadata getClassFromClassLoader(String clazz) throws ClassNotFoundException,IOException;
+  String getHumanClasspath();
 }
diff --git a/src/main/java/de/thetaphi/forbiddenapis/Signatures.java b/src/main/java/de/thetaphi/forbiddenapis/Signatures.java
index a98a8c15..f20d573f 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/Signatures.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/Signatures.java
@@ -190,6 +190,9 @@ private void addSignature(final String line, final String defaultMessage, final
           return;
         }
         if (report.reportClassNotFound) {
+          if (report != UnresolvableReporting.SILENT && lookup.getHumanClasspath() != null) {
+            logger.debug("Classpath: " + lookup.getHumanClasspath());
+          }
           report.parseFailed(logger, String.format(Locale.ENGLISH, "Class '%s' not found on classpath", cnfe.getMessage()), signature);
         } else {
           missingClasses.add(clazz);
@@ -231,6 +234,9 @@ private void reportMissingSignatureClasses(Set<String> missingClasses) {
     if (missingClasses.isEmpty()) {
       return;
     }
+    if (lookup.getHumanClasspath() != null) {
+      logger.debug("Classpath: " + lookup.getHumanClasspath());
+    }
     logger.warn("Some signatures were ignored because the following classes were not found on classpath:");
     final StringBuilder sb = new StringBuilder();
     int count = 0;
diff --git a/src/main/java/de/thetaphi/forbiddenapis/StdIoLogger.java b/src/main/java/de/thetaphi/forbiddenapis/StdIoLogger.java
index 7f920c9b..f98d6c8f 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/StdIoLogger.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/StdIoLogger.java
@@ -38,4 +38,9 @@ public void info(String msg) {
     System.out.println(msg);
   }
   
+  @Override
+  public void debug(String msg) {
+    // no reporting of debug messages
+  }
+  
 }
diff --git a/src/main/java/de/thetaphi/forbiddenapis/ant/AntTask.java b/src/main/java/de/thetaphi/forbiddenapis/ant/AntTask.java
index 471ea63e..6c9dd04d 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/ant/AntTask.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/ant/AntTask.java
@@ -91,6 +91,11 @@ public void warn(String msg) {
       public void info(String msg) {
         log(msg, Project.MSG_INFO);
       }
+      
+      @Override
+      public void debug(String msg) {
+        log(msg, Project.MSG_DEBUG);
+      }
     };
     
     AntClassLoader antLoader = null;
@@ -116,7 +121,7 @@ public void info(String msg) {
       }
       if (ignoreSignaturesOfMissingClasses) options.add(IGNORE_SIGNATURES_OF_MISSING_CLASSES);
       if (disableClassloadingCache) options.add(DISABLE_CLASSLOADING_CACHE);
-      final Checker checker = new Checker(log, loader, options);
+      final Checker checker = new Checker(log, loader, (classpath == null) ? null : classpath.toString(), options);
       
       if (!checker.isSupportedJDK) {
         final String msg = String.format(Locale.ENGLISH, 
diff --git a/src/main/java/de/thetaphi/forbiddenapis/cli/CliMain.java b/src/main/java/de/thetaphi/forbiddenapis/cli/CliMain.java
index f4b0f0c3..27e37ce5 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/cli/CliMain.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/cli/CliMain.java
@@ -196,16 +196,22 @@ public void run() throws ExitException {
     // parse classpath given as argument; add -d to classpath, too
     final String[] classpath = cmd.getOptionValues(classpathOpt.getLongOpt());
     final URL[] urls;
+    final CharSequence humanClasspath;
     try {
       if (classpath == null) {
         urls = new URL[] { classesDirectory.toURI().toURL() };
+        humanClasspath = classesDirectory.toString();
       } else {
         urls = new URL[classpath.length + 1];
         int i = 0;
+        final StringBuilder sb = new StringBuilder();
         for (final String cpElement : classpath) {
           urls[i++] = new File(cpElement).toURI().toURL();
+          sb.append(cpElement).append(File.pathSeparatorChar);
         }
         urls[i++] = classesDirectory.toURI().toURL();
+        sb.append(classesDirectory.toString());
+        humanClasspath = sb;
         assert i == urls.length;
       }
     } catch (MalformedURLException mfue) {
@@ -222,7 +228,7 @@ public void run() throws ExitException {
         options.add(FAIL_ON_UNRESOLVABLE_SIGNATURES);
       }
       if (cmd.hasOption(ignoresignaturesofmissingclassesOpt.getLongOpt())) options.add(IGNORE_SIGNATURES_OF_MISSING_CLASSES);
-      final Checker checker = new Checker(LOG, loader, options);
+      final Checker checker = new Checker(LOG, loader, humanClasspath.toString(), options);
       
       if (!checker.isSupportedJDK) {
         throw new ExitException(EXIT_UNSUPPORTED_JDK, String.format(Locale.ENGLISH, 
diff --git a/src/main/java/de/thetaphi/forbiddenapis/gradle/CheckForbiddenApis.java b/src/main/java/de/thetaphi/forbiddenapis/gradle/CheckForbiddenApis.java
index b5cf364b..51a0ef5a 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/gradle/CheckForbiddenApis.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/gradle/CheckForbiddenApis.java
@@ -498,16 +498,26 @@ public void warn(String msg) {
       public void info(String msg) {
         getLogger().info(msg);
       }
+      
+      @Override
+      public void debug(String msg) {
+        getLogger().debug(msg);
+      }
     };
     
     final Set<File> cpElements = new LinkedHashSet<>();
     cpElements.addAll(classpath.getFiles());
     cpElements.addAll(classesDirs.getFiles());
     final URL[] urls = new URL[cpElements.size()];
+    final StringBuilder humanClasspath = new StringBuilder();
     try {
       int i = 0;
       for (final File cpElement : cpElements) {
         urls[i++] = cpElement.toURI().toURL();
+        if (humanClasspath.length() > 0) {
+          humanClasspath.append(File.pathSeparatorChar);
+        }
+        humanClasspath.append(cpElement);
       }
       assert i == urls.length;
     } catch (MalformedURLException mfue) {
@@ -530,7 +540,7 @@ public void info(String msg) {
       }
       if (getIgnoreSignaturesOfMissingClasses()) options.add(IGNORE_SIGNATURES_OF_MISSING_CLASSES);
       if (getDisableClassloadingCache()) options.add(DISABLE_CLASSLOADING_CACHE);
-      final Checker checker = new Checker(log, loader, options);
+      final Checker checker = new Checker(log, loader, humanClasspath.toString(), options);
       
       if (!checker.isSupportedJDK) {
         final String msg = String.format(Locale.ENGLISH, 
diff --git a/src/main/java/de/thetaphi/forbiddenapis/maven/AbstractCheckMojo.java b/src/main/java/de/thetaphi/forbiddenapis/maven/AbstractCheckMojo.java
index 04873559..02aea0e7 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/maven/AbstractCheckMojo.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/maven/AbstractCheckMojo.java
@@ -304,6 +304,11 @@ public void warn(String msg) {
       public void info(String msg) {
         getLog().info(msg);
       }
+      
+      @Override
+      public void debug(String msg) {
+        getLog().debug(msg);
+      }
     };
     
     if (skip) {
@@ -323,10 +328,15 @@ public void info(String msg) {
     
     final List<String> cp = getClassPathElements();
     final URL[] urls = new URL[cp.size()];
+    final StringBuilder humanClasspath = new StringBuilder();
     try {
       int i = 0;
       for (final String cpElement : cp) {
         urls[i++] = new File(cpElement).toURI().toURL();
+        if (humanClasspath.length() > 0) {
+          humanClasspath.append(File.pathSeparatorChar);
+        }
+        humanClasspath.append(cpElement);
       }
       assert i == urls.length;
     } catch (MalformedURLException e) {
@@ -349,7 +359,7 @@ public void info(String msg) {
       }
       if (ignoreSignaturesOfMissingClasses) options.add(IGNORE_SIGNATURES_OF_MISSING_CLASSES);
       if (disableClassloadingCache) options.add(DISABLE_CLASSLOADING_CACHE);
-      final Checker checker = new Checker(log, loader, options);
+      final Checker checker = new Checker(log, loader, humanClasspath.toString(), options);
       
       if (!checker.isSupportedJDK) {
         final String msg = String.format(Locale.ENGLISH, 
diff --git a/src/test/java/de/thetaphi/forbiddenapis/CheckerSetupTest.java b/src/test/java/de/thetaphi/forbiddenapis/CheckerSetupTest.java
index 670082e0..d2bfdd59 100644
--- a/src/test/java/de/thetaphi/forbiddenapis/CheckerSetupTest.java
+++ b/src/test/java/de/thetaphi/forbiddenapis/CheckerSetupTest.java
@@ -35,7 +35,7 @@ public final class CheckerSetupTest {
   
   @Before
   public void setUp() {
-    checker = new Checker(StdIoLogger.INSTANCE, ClassLoader.getSystemClassLoader(), FAIL_ON_MISSING_CLASSES, FAIL_ON_VIOLATION, FAIL_ON_UNRESOLVABLE_SIGNATURES);
+    checker = new Checker(StdIoLogger.INSTANCE, ClassLoader.getSystemClassLoader(), null, FAIL_ON_MISSING_CLASSES, FAIL_ON_VIOLATION, FAIL_ON_UNRESOLVABLE_SIGNATURES);
     assumeTrue("This test only works with a supported JDK (see docs)", checker.isSupportedJDK);
     assertEquals(EnumSet.of(FAIL_ON_MISSING_CLASSES, FAIL_ON_VIOLATION, FAIL_ON_UNRESOLVABLE_SIGNATURES), checker.options);
     forbiddenSignatures = checker.forbiddenSignatures;
@@ -146,7 +146,7 @@ public void testWildcardMethodSignatureNotExist() throws Exception {
   
   @Test
   public void testEmptyCtor() throws Exception {
-    Checker chk = new Checker(StdIoLogger.INSTANCE, ClassLoader.getSystemClassLoader());
+    Checker chk = new Checker(StdIoLogger.INSTANCE, ClassLoader.getSystemClassLoader(), null);
     assertEquals(EnumSet.noneOf(Checker.Option.class), chk.options);
   }
   

From 571ab1e65b863b703ad4d35beef89a1fa8d007c7 Mon Sep 17 00:00:00 2001
From: Uwe Schindler <uwe@thetaphi.de>
Date: Sat, 24 Sep 2022 13:47:11 +0200
Subject: [PATCH 2/2] Just report classpath in all tasks separately and remove
 changes from Checker itsself

---
 .../java/de/thetaphi/forbiddenapis/Checker.java     | 13 +++----------
 .../thetaphi/forbiddenapis/RelatedClassLookup.java  |  1 -
 .../java/de/thetaphi/forbiddenapis/Signatures.java  |  6 ------
 .../java/de/thetaphi/forbiddenapis/ant/AntTask.java |  3 ++-
 .../java/de/thetaphi/forbiddenapis/cli/CliMain.java |  8 +-------
 .../forbiddenapis/gradle/CheckForbiddenApis.java    |  3 ++-
 .../forbiddenapis/maven/AbstractCheckMojo.java      |  3 ++-
 .../de/thetaphi/forbiddenapis/CheckerSetupTest.java |  4 ++--
 8 files changed, 12 insertions(+), 29 deletions(-)

diff --git a/src/main/java/de/thetaphi/forbiddenapis/Checker.java b/src/main/java/de/thetaphi/forbiddenapis/Checker.java
index 9204f904..8819e640 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/Checker.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/Checker.java
@@ -66,7 +66,6 @@ public static enum Option {
   final Logger logger;
   
   final ClassLoader loader;
-  final String humanClasspath;
   final java.lang.reflect.Method method_Class_getModule, method_Module_getName;
   final EnumSet<Option> options;
   
@@ -80,14 +79,13 @@ public static enum Option {
   /** descriptors (not internal names) of all annotations that suppress */
   final Set<String> suppressAnnotations = new LinkedHashSet<>();
     
-  public Checker(Logger logger, ClassLoader loader, String humanClasspath, Option... options) {
-    this(logger, loader, humanClasspath, (options.length == 0) ? EnumSet.noneOf(Option.class) : EnumSet.copyOf(Arrays.asList(options)));
+  public Checker(Logger logger, ClassLoader loader, Option... options) {
+    this(logger, loader, (options.length == 0) ? EnumSet.noneOf(Option.class) : EnumSet.copyOf(Arrays.asList(options)));
   }
   
-  public Checker(Logger logger, ClassLoader loader, String humanClasspath, EnumSet<Option> options) {
+  public Checker(Logger logger, ClassLoader loader, EnumSet<Option> options) {
     this.logger = logger;
     this.loader = loader;
-    this.humanClasspath = (humanClasspath == null || humanClasspath.isEmpty()) ? null : humanClasspath;
     this.options = options;
     this.start = System.currentTimeMillis();
     
@@ -323,11 +321,6 @@ public ClassMetadata lookupRelatedClass(String internalName, String internalName
     }
   }
   
-  @Override
-  public String getHumanClasspath() {
-    return humanClasspath;
-  }
-  
   /** Reads a list of bundled API signatures from classpath. */
   public void addBundledSignatures(String name, String jdkTargetVersion) throws IOException,ParseException {
     forbiddenSignatures.addBundledSignatures(name, jdkTargetVersion);
diff --git a/src/main/java/de/thetaphi/forbiddenapis/RelatedClassLookup.java b/src/main/java/de/thetaphi/forbiddenapis/RelatedClassLookup.java
index 42e8463a..d167b055 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/RelatedClassLookup.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/RelatedClassLookup.java
@@ -21,5 +21,4 @@
 public interface RelatedClassLookup {
   ClassMetadata lookupRelatedClass(String internalName, String internalNameOrig);
   ClassMetadata getClassFromClassLoader(String clazz) throws ClassNotFoundException,IOException;
-  String getHumanClasspath();
 }
diff --git a/src/main/java/de/thetaphi/forbiddenapis/Signatures.java b/src/main/java/de/thetaphi/forbiddenapis/Signatures.java
index f20d573f..a98a8c15 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/Signatures.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/Signatures.java
@@ -190,9 +190,6 @@ private void addSignature(final String line, final String defaultMessage, final
           return;
         }
         if (report.reportClassNotFound) {
-          if (report != UnresolvableReporting.SILENT && lookup.getHumanClasspath() != null) {
-            logger.debug("Classpath: " + lookup.getHumanClasspath());
-          }
           report.parseFailed(logger, String.format(Locale.ENGLISH, "Class '%s' not found on classpath", cnfe.getMessage()), signature);
         } else {
           missingClasses.add(clazz);
@@ -234,9 +231,6 @@ private void reportMissingSignatureClasses(Set<String> missingClasses) {
     if (missingClasses.isEmpty()) {
       return;
     }
-    if (lookup.getHumanClasspath() != null) {
-      logger.debug("Classpath: " + lookup.getHumanClasspath());
-    }
     logger.warn("Some signatures were ignored because the following classes were not found on classpath:");
     final StringBuilder sb = new StringBuilder();
     int count = 0;
diff --git a/src/main/java/de/thetaphi/forbiddenapis/ant/AntTask.java b/src/main/java/de/thetaphi/forbiddenapis/ant/AntTask.java
index 6c9dd04d..b93b1986 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/ant/AntTask.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/ant/AntTask.java
@@ -105,6 +105,7 @@ public void debug(String msg) {
         classpath.setProject(getProject());
         loader = antLoader = getProject().createClassLoader(ClassLoader.getSystemClassLoader(), classpath);
         antLoader.setParentFirst(true); // use default classloader delegation
+        log.debug("Classpath: " + classpath.toString());
       } else {
         loader = ClassLoader.getSystemClassLoader();
       }
@@ -121,7 +122,7 @@ public void debug(String msg) {
       }
       if (ignoreSignaturesOfMissingClasses) options.add(IGNORE_SIGNATURES_OF_MISSING_CLASSES);
       if (disableClassloadingCache) options.add(DISABLE_CLASSLOADING_CACHE);
-      final Checker checker = new Checker(log, loader, (classpath == null) ? null : classpath.toString(), options);
+      final Checker checker = new Checker(log, loader, options);
       
       if (!checker.isSupportedJDK) {
         final String msg = String.format(Locale.ENGLISH, 
diff --git a/src/main/java/de/thetaphi/forbiddenapis/cli/CliMain.java b/src/main/java/de/thetaphi/forbiddenapis/cli/CliMain.java
index 27e37ce5..f4b0f0c3 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/cli/CliMain.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/cli/CliMain.java
@@ -196,22 +196,16 @@ public void run() throws ExitException {
     // parse classpath given as argument; add -d to classpath, too
     final String[] classpath = cmd.getOptionValues(classpathOpt.getLongOpt());
     final URL[] urls;
-    final CharSequence humanClasspath;
     try {
       if (classpath == null) {
         urls = new URL[] { classesDirectory.toURI().toURL() };
-        humanClasspath = classesDirectory.toString();
       } else {
         urls = new URL[classpath.length + 1];
         int i = 0;
-        final StringBuilder sb = new StringBuilder();
         for (final String cpElement : classpath) {
           urls[i++] = new File(cpElement).toURI().toURL();
-          sb.append(cpElement).append(File.pathSeparatorChar);
         }
         urls[i++] = classesDirectory.toURI().toURL();
-        sb.append(classesDirectory.toString());
-        humanClasspath = sb;
         assert i == urls.length;
       }
     } catch (MalformedURLException mfue) {
@@ -228,7 +222,7 @@ public void run() throws ExitException {
         options.add(FAIL_ON_UNRESOLVABLE_SIGNATURES);
       }
       if (cmd.hasOption(ignoresignaturesofmissingclassesOpt.getLongOpt())) options.add(IGNORE_SIGNATURES_OF_MISSING_CLASSES);
-      final Checker checker = new Checker(LOG, loader, humanClasspath.toString(), options);
+      final Checker checker = new Checker(LOG, loader, options);
       
       if (!checker.isSupportedJDK) {
         throw new ExitException(EXIT_UNSUPPORTED_JDK, String.format(Locale.ENGLISH, 
diff --git a/src/main/java/de/thetaphi/forbiddenapis/gradle/CheckForbiddenApis.java b/src/main/java/de/thetaphi/forbiddenapis/gradle/CheckForbiddenApis.java
index 51a0ef5a..8f25927e 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/gradle/CheckForbiddenApis.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/gradle/CheckForbiddenApis.java
@@ -523,6 +523,7 @@ public void debug(String msg) {
     } catch (MalformedURLException mfue) {
       throw new InvalidUserDataException("Failed to build classpath URLs.", mfue);
     }
+    log.debug("Classpath: " + humanClasspath);
 
     URLClassLoader urlLoader = null;
     final ClassLoader loader = (urls.length > 0) ?
@@ -540,7 +541,7 @@ public void debug(String msg) {
       }
       if (getIgnoreSignaturesOfMissingClasses()) options.add(IGNORE_SIGNATURES_OF_MISSING_CLASSES);
       if (getDisableClassloadingCache()) options.add(DISABLE_CLASSLOADING_CACHE);
-      final Checker checker = new Checker(log, loader, humanClasspath.toString(), options);
+      final Checker checker = new Checker(log, loader, options);
       
       if (!checker.isSupportedJDK) {
         final String msg = String.format(Locale.ENGLISH, 
diff --git a/src/main/java/de/thetaphi/forbiddenapis/maven/AbstractCheckMojo.java b/src/main/java/de/thetaphi/forbiddenapis/maven/AbstractCheckMojo.java
index 02aea0e7..de754d0f 100644
--- a/src/main/java/de/thetaphi/forbiddenapis/maven/AbstractCheckMojo.java
+++ b/src/main/java/de/thetaphi/forbiddenapis/maven/AbstractCheckMojo.java
@@ -342,6 +342,7 @@ public void debug(String msg) {
     } catch (MalformedURLException e) {
       throw new MojoExecutionException("Failed to build classpath.", e);
     }
+    log.debug("Classpath: " + humanClasspath);
 
     URLClassLoader urlLoader = null;
     final ClassLoader loader = (urls.length > 0) ?
@@ -359,7 +360,7 @@ public void debug(String msg) {
       }
       if (ignoreSignaturesOfMissingClasses) options.add(IGNORE_SIGNATURES_OF_MISSING_CLASSES);
       if (disableClassloadingCache) options.add(DISABLE_CLASSLOADING_CACHE);
-      final Checker checker = new Checker(log, loader, humanClasspath.toString(), options);
+      final Checker checker = new Checker(log, loader, options);
       
       if (!checker.isSupportedJDK) {
         final String msg = String.format(Locale.ENGLISH, 
diff --git a/src/test/java/de/thetaphi/forbiddenapis/CheckerSetupTest.java b/src/test/java/de/thetaphi/forbiddenapis/CheckerSetupTest.java
index d2bfdd59..670082e0 100644
--- a/src/test/java/de/thetaphi/forbiddenapis/CheckerSetupTest.java
+++ b/src/test/java/de/thetaphi/forbiddenapis/CheckerSetupTest.java
@@ -35,7 +35,7 @@ public final class CheckerSetupTest {
   
   @Before
   public void setUp() {
-    checker = new Checker(StdIoLogger.INSTANCE, ClassLoader.getSystemClassLoader(), null, FAIL_ON_MISSING_CLASSES, FAIL_ON_VIOLATION, FAIL_ON_UNRESOLVABLE_SIGNATURES);
+    checker = new Checker(StdIoLogger.INSTANCE, ClassLoader.getSystemClassLoader(), FAIL_ON_MISSING_CLASSES, FAIL_ON_VIOLATION, FAIL_ON_UNRESOLVABLE_SIGNATURES);
     assumeTrue("This test only works with a supported JDK (see docs)", checker.isSupportedJDK);
     assertEquals(EnumSet.of(FAIL_ON_MISSING_CLASSES, FAIL_ON_VIOLATION, FAIL_ON_UNRESOLVABLE_SIGNATURES), checker.options);
     forbiddenSignatures = checker.forbiddenSignatures;
@@ -146,7 +146,7 @@ public void testWildcardMethodSignatureNotExist() throws Exception {
   
   @Test
   public void testEmptyCtor() throws Exception {
-    Checker chk = new Checker(StdIoLogger.INSTANCE, ClassLoader.getSystemClassLoader(), null);
+    Checker chk = new Checker(StdIoLogger.INSTANCE, ClassLoader.getSystemClassLoader());
     assertEquals(EnumSet.noneOf(Checker.Option.class), chk.options);
   }