Implementation

eed3si9n · Jan 27, 2024 · 87d7d05 · 87d7d05
1 parent 9d0eb03
commit 87d7d05
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Showing 14 changed files with 177 additions and 38 deletions.
diff --git a/core/src/main/scala/com/eed3si9n/jarjar/JJProcessor.scala b/core/src/main/scala/com/eed3si9n/jarjar/JJProcessor.scala
@@ -52,7 +52,7 @@ class JJProcessor(
   processors += new ZapProcessor(zapList.asJava)
   processors += misplacedClassProcessor
   processors += new JarTransformerChain(
-    Array[RemappingClassTransformer](new RemappingClassTransformer(pr))
+    Array[RemappingClassTransformer](new RemappingClassTransformer()), pr
   )
 
   val renamer: String => Option[String] = {

diff --git a/jarjar/src/main/java/com/eed3si9n/jarjar/MainProcessor.java b/jarjar/src/main/java/com/eed3si9n/jarjar/MainProcessor.java
@@ -74,8 +74,8 @@ public MainProcessor(List<PatternElement> patterns, boolean verbose, boolean ski
         processors.add(new ZapProcessor(zapList));
         processors.add(misplacedClassProcessor);
         processors.add(new JarTransformerChain(new RemappingClassTransformer[] {
-            new RemappingClassTransformer(pr)
-        }));
+            new RemappingClassTransformer()
+        }, pr));
         processors.add(new MethodSignatureProcessor(pr));
         processors.add(new ResourceProcessor(pr));
         chain = new JarProcessorChain(processors.toArray(new JarProcessor[processors.size()]));

diff --git a/jarjar/src/main/java/com/eed3si9n/jarjar/MethodSignatureProcessor.java b/jarjar/src/main/java/com/eed3si9n/jarjar/MethodSignatureProcessor.java
@@ -4,6 +4,8 @@
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
+
+import com.eed3si9n.jarjar.util.RemappingJarProcessor;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.ClassWriter;
@@ -20,7 +22,7 @@
  * being renamed. Method signatures are more difficult to detect so this class keeps track of which
  * methods definitely take method signatures and remaps those explicitly.
  */
-public class MethodSignatureProcessor implements JarProcessor {
+public class MethodSignatureProcessor extends RemappingJarProcessor {
 
   /**
    * List of method names which take a method signature as their parameter.
@@ -30,14 +32,12 @@ public class MethodSignatureProcessor implements JarProcessor {
   private static final Set<String> METHOD_NAMES_WITH_PARAMS_TO_REWRITE =
       new HashSet<String>(Arrays.asList("getImplMethodSignature"));
 
-  private final Remapper remapper;
-
-  public MethodSignatureProcessor(Remapper remapper) {
-    this.remapper = remapper;
+  public MethodSignatureProcessor(TracingRemapper remapper) {
+    super(remapper);
   }
 
   @Override
-  public boolean process(final EntryStruct struct) throws IOException {
+  public boolean processImpl(EntryStruct struct, Remapper remapper) throws IOException {
     if (!struct.name.endsWith(".class") || struct.skipTransform) {
       return true;
     }
@@ -50,12 +50,14 @@ public boolean process(final EntryStruct struct) throws IOException {
       e.printStackTrace();
       return true;
     }
-    reader.accept(new MethodSignatureRemapperClassVisitor(classWriter), ClassReader.EXPAND_FRAMES);
+    reader.accept(new MethodSignatureRemapperClassVisitor(classWriter, remapper), ClassReader.EXPAND_FRAMES);
     struct.data = classWriter.toByteArray();
     return true;
   }
 
-  private class MethodSignatureRemapperClassVisitor extends ClassVisitor {
+  private static class MethodSignatureRemapperClassVisitor extends ClassVisitor {
+
+    private final Remapper remapper;
 
     private class MethodSignatureRemapperMethodVisitor extends MethodVisitor {
 
@@ -96,8 +98,9 @@ public void visitLdcInsn(Object value) {
       }
     }
 
-    public MethodSignatureRemapperClassVisitor(ClassVisitor classVisitor) {
+    public MethodSignatureRemapperClassVisitor(ClassVisitor classVisitor, Remapper remapper) {
       super(Opcodes.ASM9, classVisitor);
+      this.remapper = remapper;
     }
 
     @Override

diff --git a/jarjar/src/main/java/com/eed3si9n/jarjar/PackageRemapper.java b/jarjar/src/main/java/com/eed3si9n/jarjar/PackageRemapper.java
@@ -21,24 +21,33 @@
 import java.util.*;
 import java.util.regex.Pattern;
 
-class PackageRemapper extends Remapper
+class PackageRemapper extends TracingRemapper
 {
     private static final String RESOURCE_SUFFIX = "RESOURCE";
 
     private static final Pattern ARRAY_FOR_NAME_PATTERN
         = Pattern.compile("\\[L[\\p{javaJavaIdentifierPart}\\.]+?;");
 
     private final List<Wildcard> wildcards;
+    private final List<Rule> ruleList;
     private final Map<String, String> typeCache = new HashMap<String, String>();
     private final Map<String, String> pathCache = new HashMap<String, String>();
     private final Map<Object, String> valueCache = new HashMap<Object, String>();
     private final boolean verbose;
+    private boolean modified = false;
+
 
     public PackageRemapper(List<Rule> ruleList, boolean verbose) {
         this.verbose = verbose;
+        this.ruleList = ruleList;
         wildcards = PatternElement.createWildcards(ruleList);
     }
 
+    @Override
+    public TracingRemapper copy() {
+        return new PackageRemapper(this.ruleList, this.verbose);
+    }
+
     // also used by KeepProcessor
     static boolean isArrayForName(String value) {
       return ARRAY_FOR_NAME_PATTERN.matcher(value).matches();
@@ -130,9 +139,17 @@ public String mapInnerClassName(
     private String replaceHelper(String value) {
         for (Wildcard wildcard : wildcards) {
             String test = wildcard.replace(value);
-            if (test != null)
+            if (test != null) {
+                if (!test.equals(value))
+                    this.modified = true;
                 return test;
+            }
         }
         return value;
     }
+
+    @Override
+    public boolean hasChanges() {
+        return modified;
+    }
 }
diff --git a/jarjar/src/main/java/com/eed3si9n/jarjar/TracingRemapper.java b/jarjar/src/main/java/com/eed3si9n/jarjar/TracingRemapper.java
@@ -0,0 +1,15 @@
+package com.eed3si9n.jarjar;
+
+import org.objectweb.asm.commons.Remapper;
+
+public abstract class TracingRemapper extends Remapper {
+    /**
+     * Obtain the fresh copy of this object.
+     */
+    public abstract TracingRemapper copy();
+
+    /**
+     * Check if this instance remapped something already.
+     */
+    public abstract boolean hasChanges();
+}
diff --git a/jarjar/src/main/java/com/eed3si9n/jarjar/util/EntryStruct.java b/jarjar/src/main/java/com/eed3si9n/jarjar/util/EntryStruct.java
@@ -21,4 +21,13 @@ public class EntryStruct {
     public String name;
     public long time;
     public boolean skipTransform;
+
+    public EntryStruct copy() {
+        EntryStruct result = new EntryStruct();
+        result.data = data;
+        result.name = name;
+        result.time = time;
+        result.skipTransform = skipTransform;
+        return result;
+    }
 }
diff --git a/jarjar/src/main/java/com/eed3si9n/jarjar/util/JarTransformer.java b/jarjar/src/main/java/com/eed3si9n/jarjar/util/JarTransformer.java
@@ -19,13 +19,20 @@
 import java.io.*;
 
 import static com.eed3si9n.jarjar.misplaced.MisplacedClassProcessor.VERSIONED_CLASS_FOLDER;
+
+import com.eed3si9n.jarjar.TracingRemapper;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.commons.Remapper;
+
+abstract public class JarTransformer extends RemappingJarProcessor {
 
-abstract public class JarTransformer implements JarProcessor {
+    public JarTransformer(TracingRemapper remapper) {
+        super(remapper);
+    }
 
-    public boolean process(EntryStruct struct) throws IOException {
+    public boolean processImpl(EntryStruct struct, Remapper remapper) throws IOException {
         if (struct.name.endsWith(".class") && !struct.skipTransform) {
             ClassReader reader;
             try {
@@ -38,7 +45,7 @@ public boolean process(EntryStruct struct) throws IOException {
 
             GetNameClassWriter w = new GetNameClassWriter(ClassWriter.COMPUTE_MAXS);
             try {
-                reader.accept(transform(w), ClassReader.EXPAND_FRAMES);
+                reader.accept(transform(w, remapper), ClassReader.EXPAND_FRAMES);
             } catch (RuntimeException e) {
                 throw new IOException("Unable to transform " + struct.name, e);
             }
@@ -51,7 +58,7 @@ public boolean process(EntryStruct struct) throws IOException {
         return true;
     }
 
-    abstract protected ClassVisitor transform(ClassVisitor v);
+    abstract protected ClassVisitor transform(ClassVisitor v, Remapper remapper);
 
     private static String pathFromName(String className) {
         return className.replace('.', '/') + ".class";

diff --git a/jarjar/src/main/java/com/eed3si9n/jarjar/util/JarTransformerChain.java b/jarjar/src/main/java/com/eed3si9n/jarjar/util/JarTransformerChain.java
@@ -16,21 +16,24 @@
 
 package com.eed3si9n.jarjar.util;
 
+import com.eed3si9n.jarjar.TracingRemapper;
 import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.commons.Remapper;
 
 public class JarTransformerChain extends JarTransformer
 {
     private final RemappingClassTransformer[] chain;
 
-    public JarTransformerChain(RemappingClassTransformer[] chain) {
+    public JarTransformerChain(RemappingClassTransformer[] chain, TracingRemapper remapper) {
+        super(remapper);
         this.chain = chain.clone();
-        for (int i = chain.length - 1; i > 0; i--) {
-            chain[i - 1].setTarget(chain[i]);
-        }
     }
 
-    protected ClassVisitor transform(ClassVisitor v) {
-        chain[chain.length - 1].setTarget(v);
-        return chain[0];
+    protected ClassVisitor transform(ClassVisitor parent, Remapper remapper) {
+        for (int i = chain.length - 1; i >= 0; i--) {
+            chain[i] = chain[i].update(remapper, parent);
+            parent = chain[i];
+        }
+        return parent;
     }
 }
diff --git a/jarjar/src/main/java/com/eed3si9n/jarjar/util/RemappingClassTransformer.java b/jarjar/src/main/java/com/eed3si9n/jarjar/util/RemappingClassTransformer.java
@@ -24,11 +24,16 @@
 
 public class RemappingClassTransformer extends ClassRemapper
 {
-    public RemappingClassTransformer(Remapper pr) {
+    public RemappingClassTransformer() {
+        this(null, null);
+    }
+
+    public RemappingClassTransformer(Remapper pr, ClassVisitor parent) {
         super(new EmptyClassVisitor(), pr);
+        this.cv = parent;
     }
-        
-    public void setTarget(ClassVisitor target) {
-        cv = target;
+
+    public RemappingClassTransformer update(Remapper pr, ClassVisitor target) {
+        return new RemappingClassTransformer(pr, target);
     }
 }
diff --git a/jarjar/src/main/java/com/eed3si9n/jarjar/util/RemappingJarProcessor.java b/jarjar/src/main/java/com/eed3si9n/jarjar/util/RemappingJarProcessor.java
@@ -0,0 +1,41 @@
+package com.eed3si9n.jarjar.util;
+
+
+import com.eed3si9n.jarjar.TracingRemapper;
+import org.objectweb.asm.commons.Remapper;
+
+import java.io.IOException;
+
+/**
+ * Extension of JarProcessor for building processors around TracingRemapper.
+ *
+ * This class will track if TracingRemapper recorded doing any changes, and if it didn't,
+ * it will make sure that the underlying bytes are unmodified.
+ *
+ * This helps to avoid bytecode modifications when there was no actual changes
+ * to do.
+ */
+public abstract class RemappingJarProcessor implements JarProcessor {
+    private TracingRemapper remapper;
+
+    public RemappingJarProcessor(TracingRemapper remapper) {
+        this.remapper = remapper;
+    }
+
+    public final boolean process(EntryStruct struct) throws IOException {
+        TracingRemapper structRemapper = remapper.copy();
+        EntryStruct origStruct = struct.copy();
+
+        if (!processImpl(struct, structRemapper)) {
+            return false;
+        }
+
+        if (!structRemapper.hasChanges()) {
+            struct.data = origStruct.data;
+        }
+
+        return true;
+    }
+
+    protected abstract boolean processImpl(EntryStruct struct, Remapper remapper) throws IOException;
+}
diff --git a/jarjar/src/test/java/com/eed3si9n/jarjar/GenericsTest.java b/jarjar/src/test/java/com/eed3si9n/jarjar/GenericsTest.java
@@ -32,8 +32,9 @@ public void testTransform() throws Exception {
          Rule rule = new Rule();
          rule.setPattern("java.lang.String");
          rule.setResult("com.tonicsystems.String");
-         RemappingClassTransformer t = new RemappingClassTransformer(new PackageRemapper(Arrays.asList(rule), false));
-         t.setTarget(new EmptyClassVisitor());
+         RemappingClassTransformer t = new RemappingClassTransformer(
+                 new PackageRemapper(Arrays.asList(rule), false), new EmptyClassVisitor()
+         );
          ClassReader reader = new ClassReader(getClass().getResourceAsStream("/Generics.class"));
          reader.accept(t, 0);
     }

diff --git a/jarjar/src/test/java/com/eed3si9n/jarjar/MethodRewriterTest.java b/jarjar/src/test/java/com/eed3si9n/jarjar/MethodRewriterTest.java
@@ -46,7 +46,7 @@ public MethodVisitor visitMethod(
     }
   }
 
-  private static byte[] readInputStream(InputStream inputStream) throws IOException {
+  protected static byte[] readInputStream(InputStream inputStream) throws IOException {
     byte[] buf = new byte[0x2000];
     ByteArrayOutputStream baos = new ByteArrayOutputStream();
     IoUtil.pipe(inputStream, baos, buf);

diff --git a/jarjar/src/test/java/com/eed3si9n/jarjar/UnmodifiedTest.java b/jarjar/src/test/java/com/eed3si9n/jarjar/UnmodifiedTest.java
@@ -0,0 +1,35 @@
+package com.eed3si9n.jarjar;
+
+import com.eed3si9n.jarjar.util.EntryStruct;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static com.eed3si9n.jarjar.MethodRewriterTest.readInputStream;
+
+public class UnmodifiedTest {
+    @Test
+    public void testNotModified() throws Exception {
+        Rule rule = new Rule();
+        rule.setPattern("com.abc");
+        rule.setResult("com.def");
+
+        MainProcessor mp = new MainProcessor(Arrays.asList(rule), false, false, "move");
+
+        EntryStruct entryStruct = new EntryStruct();
+        entryStruct.name = "BigtableIO$Write.class";
+        entryStruct.skipTransform = false;
+        entryStruct.time = 0;
+        entryStruct.data =
+                readInputStream(
+                        getClass().getResourceAsStream("/com/eed3si9n/jarjar/BigtableIO$Write.class"));
+
+        EntryStruct orig = entryStruct.copy();
+
+        mp.process(entryStruct);
+
+        Assert.assertEquals(entryStruct.data, orig.data);
+    }
+}
diff --git a/jarjar/src/test/java/com/eed3si9n/jarjar/VersionedClassTest.java b/jarjar/src/test/java/com/eed3si9n/jarjar/VersionedClassTest.java
@@ -9,6 +9,7 @@
 import org.junit.Test;
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.commons.ClassRemapper;
+import org.objectweb.asm.commons.Remapper;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -37,13 +38,15 @@ public void testVersionPrefixIsPreserved() throws IOException {
         String expectedName = Example.class.getName().replace("jarjar", "jarjarabrams");
         struct.name = MisplacedClassProcessor.VERSIONED_CLASS_FOLDER + "9/" + toClassPath(originalName);
         struct.data = getClassBytes(originalName);
-        JarTransformer transformer = new JarTransformer() {
+
+        Rule rule = new Rule();
+        rule.setPattern(originalName);
+        rule.setResult(expectedName);
+        PackageRemapper remapper = new PackageRemapper(Arrays.asList(rule), false);
+
+        JarTransformer transformer = new JarTransformer(remapper) {
             @Override
-            protected ClassVisitor transform(ClassVisitor v) {
-                Rule rule = new Rule();
-                rule.setPattern(originalName);
-                rule.setResult(expectedName);
-                PackageRemapper remapper = new PackageRemapper(Arrays.asList(rule), false);
+            protected ClassVisitor transform(ClassVisitor v, Remapper remapper) {
                 return new ClassRemapper(v, remapper);
             }
         };