asm-analysis/src/main/java/org/objectweb/asm/tree/analysis/Frame.java

@@ -350,24 +350,9 @@ public class Frame<V extends Value> {
         break;
       case Opcodes.DUP_X2:
         value1 = pop();
-        if (value1.getSize() == 1) {
-          value2 = pop();
-          if (value2.getSize() == 1) {
-            value3 = pop();
-            if (value3.getSize() == 1) {
-              push(interpreter.copyOperation(insn, value1));
-              push(value3);
-              push(value2);
-              push(value1);
-              break;
-            }
-          } else {
-            push(interpreter.copyOperation(insn, value1));
-            push(value2);
-            push(value1);
+        if (value1.getSize() == 1 && executeDupX2(insn, value1, interpreter)) {
           break;
         }
-        }
         throw new AnalyzerException(insn, "Illegal use of DUP_X2");
       case Opcodes.DUP2:
         value1 = pop();
@@ -437,24 +422,9 @@ public class Frame<V extends Value> {
               break;
             }
           }
-        } else {
-          value2 = pop();
-          if (value2.getSize() == 1) {
-            value3 = pop();
-            if (value3.getSize() == 1) {
-              push(interpreter.copyOperation(insn, value1));
-              push(value3);
-              push(value2);
-              push(value1);
-              break;
-            }
-          } else {
-            push(interpreter.copyOperation(insn, value1));
-            push(value2);
-            push(value1);
+        } else if (executeDupX2(insn, value1, interpreter)) {
           break;
         }
-        }
         throw new AnalyzerException(insn, "Illegal use of DUP2_X2");
       case Opcodes.SWAP:
         value2 = pop();
@@ -640,6 +610,28 @@ public class Frame<V extends Value> {
     }
   }
 
+  private boolean executeDupX2(
+      final AbstractInsnNode insn, final V value1, final Interpreter<V> interpreter)
+      throws AnalyzerException {
+    V value2 = pop();
+    if (value2.getSize() == 1) {
+      V value3 = pop();
+      if (value3.getSize() == 1) {
+        push(interpreter.copyOperation(insn, value1));
+        push(value3);
+        push(value2);
+        push(value1);
+        return true;
+      }
+    } else {
+      push(interpreter.copyOperation(insn, value1));
+      push(value2);
+      push(value1);
+      return true;
+    }
+    return false;
+  }
+
   private void executeInvokeInsn(
       final AbstractInsnNode insn, final String methodDescriptor, final Interpreter<V> interpreter)
       throws AnalyzerException {

asm-analysis/src/main/java/org/objectweb/asm/tree/analysis/SimpleVerifier.java

@@ -254,7 +254,7 @@ public class SimpleVerifier extends BasicVerifier {
           type1 = type1.getElementType();
           type2 = type2.getElementType();
         }
-        do {
+        while (true) {
           if (type1 == null || isInterface(type1)) {
             return newArrayValue(Type.getObjectType("java/lang/Object"), numDimensions);
           }
@@ -262,7 +262,7 @@ public class SimpleVerifier extends BasicVerifier {
           if (isAssignableFrom(type1, type2)) {
             return newArrayValue(type1, numDimensions);
           }
-        } while (true);
+        }
       }
       return BasicValue.UNINITIALIZED_VALUE;
     }

asm-analysis/src/main/java/org/objectweb/asm/tree/analysis/Subroutine.java

@@ -72,9 +72,8 @@ final class Subroutine {
    */
   Subroutine(final Subroutine subroutine) {
     this.start = subroutine.start;
-    this.localsUsed = new boolean[subroutine.localsUsed.length];
+    this.localsUsed = subroutine.localsUsed.clone();
     this.callers = new ArrayList<>(subroutine.callers);
-    System.arraycopy(subroutine.localsUsed, 0, this.localsUsed, 0, subroutine.localsUsed.length);
   }
 
   /**

asm-commons/src/main/java/org/objectweb/asm/commons/AdviceAdapter.java

@@ -351,6 +351,8 @@ public abstract class AdviceAdapter extends GeneratorAdapter implements Opcodes
           popValue();
           popValue();
           break;
+        case RET:
+          break;
         default:
           throw new IllegalArgumentException(INVALID_OPCODE + opcode);
       }

asm-commons/src/main/java/org/objectweb/asm/commons/ClassRemapper.java

@@ -41,6 +41,20 @@ import org.objectweb.asm.TypePath;
 /**
  * A {@link ClassVisitor} that remaps types with a {@link Remapper}.
  *
+ * <p><i>This visitor has several limitations</i>. A non-exhaustive list is the following:
+ *
+ * <ul>
+ *   <li>it cannot remap type names in dynamically computed strings (remapping of type names in
+ *       static values is supported).
+ *   <li>it cannot remap values derived from type names at compile time, such as
+ *       <ul>
+ *         <li>type name hashcodes used by some Java compilers to implement the string switch
+ *             statement.
+ *         <li>some compound strings used by some Java compilers to implement lambda
+ *             deserialization.
+ *       </ul>
+ * </ul>
+ *
  * @author Eugene Kuleshov
  */
 public class ClassRemapper extends ClassVisitor {

asm-commons/src/main/java/org/objectweb/asm/commons/GeneratorAdapter.java

@@ -758,48 +758,7 @@ public class GeneratorAdapter extends LocalVariablesSorter {
           || to.getSort() > Type.DOUBLE) {
         throw new IllegalArgumentException("Cannot cast from " + from + " to " + to);
       }
-      if (from == Type.DOUBLE_TYPE) {
-        if (to == Type.FLOAT_TYPE) {
-          mv.visitInsn(Opcodes.D2F);
-        } else if (to == Type.LONG_TYPE) {
-          mv.visitInsn(Opcodes.D2L);
-        } else {
-          mv.visitInsn(Opcodes.D2I);
-          cast(Type.INT_TYPE, to);
-        }
-      } else if (from == Type.FLOAT_TYPE) {
-        if (to == Type.DOUBLE_TYPE) {
-          mv.visitInsn(Opcodes.F2D);
-        } else if (to == Type.LONG_TYPE) {
-          mv.visitInsn(Opcodes.F2L);
-        } else {
-          mv.visitInsn(Opcodes.F2I);
-          cast(Type.INT_TYPE, to);
-        }
-      } else if (from == Type.LONG_TYPE) {
-        if (to == Type.DOUBLE_TYPE) {
-          mv.visitInsn(Opcodes.L2D);
-        } else if (to == Type.FLOAT_TYPE) {
-          mv.visitInsn(Opcodes.L2F);
-        } else {
-          mv.visitInsn(Opcodes.L2I);
-          cast(Type.INT_TYPE, to);
-        }
-      } else {
-        if (to == Type.BYTE_TYPE) {
-          mv.visitInsn(Opcodes.I2B);
-        } else if (to == Type.CHAR_TYPE) {
-          mv.visitInsn(Opcodes.I2C);
-        } else if (to == Type.DOUBLE_TYPE) {
-          mv.visitInsn(Opcodes.I2D);
-        } else if (to == Type.FLOAT_TYPE) {
-          mv.visitInsn(Opcodes.I2F);
-        } else if (to == Type.LONG_TYPE) {
-          mv.visitInsn(Opcodes.I2L);
-        } else if (to == Type.SHORT_TYPE) {
-          mv.visitInsn(Opcodes.I2S);
-        }
-      }
+      InstructionAdapter.cast(mv, from, to);
     }
   }
 
@@ -1316,37 +1275,7 @@ public class GeneratorAdapter extends LocalVariablesSorter {
    * @param type the type of the array elements.
    */
   public void newArray(final Type type) {
-    int arrayType;
-    switch (type.getSort()) {
-      case Type.BOOLEAN:
-        arrayType = Opcodes.T_BOOLEAN;
-        break;
-      case Type.CHAR:
-        arrayType = Opcodes.T_CHAR;
-        break;
-      case Type.BYTE:
-        arrayType = Opcodes.T_BYTE;
-        break;
-      case Type.SHORT:
-        arrayType = Opcodes.T_SHORT;
-        break;
-      case Type.INT:
-        arrayType = Opcodes.T_INT;
-        break;
-      case Type.FLOAT:
-        arrayType = Opcodes.T_FLOAT;
-        break;
-      case Type.LONG:
-        arrayType = Opcodes.T_LONG;
-        break;
-      case Type.DOUBLE:
-        arrayType = Opcodes.T_DOUBLE;
-        break;
-      default:
-        typeInsn(Opcodes.ANEWARRAY, type);
-        return;
-    }
-    mv.visitIntInsn(Opcodes.NEWARRAY, arrayType);
+    InstructionAdapter.newarray(mv, type);
   }
 
   // -----------------------------------------------------------------------------------------------

asm-commons/src/main/java/org/objectweb/asm/commons/InstructionAdapter.java

@@ -895,47 +895,58 @@ public class InstructionAdapter extends MethodVisitor {
    * @param to a Type.
    */
   public void cast(final Type from, final Type to) {
+    cast(mv, from, to);
+  }
+
+  /**
+   * Generates the instruction to cast from the first given type to the other.
+   *
+   * @param methodVisitor the method visitor to use to generate the instruction.
+   * @param from a Type.
+   * @param to a Type.
+   */
+  static void cast(final MethodVisitor methodVisitor, final Type from, final Type to) {
     if (from != to) {
       if (from == Type.DOUBLE_TYPE) {
         if (to == Type.FLOAT_TYPE) {
-          mv.visitInsn(Opcodes.D2F);
+          methodVisitor.visitInsn(Opcodes.D2F);
         } else if (to == Type.LONG_TYPE) {
-          mv.visitInsn(Opcodes.D2L);
+          methodVisitor.visitInsn(Opcodes.D2L);
         } else {
-          mv.visitInsn(Opcodes.D2I);
-          cast(Type.INT_TYPE, to);
+          methodVisitor.visitInsn(Opcodes.D2I);
+          cast(methodVisitor, Type.INT_TYPE, to);
         }
       } else if (from == Type.FLOAT_TYPE) {
         if (to == Type.DOUBLE_TYPE) {
-          mv.visitInsn(Opcodes.F2D);
+          methodVisitor.visitInsn(Opcodes.F2D);
         } else if (to == Type.LONG_TYPE) {
-          mv.visitInsn(Opcodes.F2L);
+          methodVisitor.visitInsn(Opcodes.F2L);
         } else {
-          mv.visitInsn(Opcodes.F2I);
-          cast(Type.INT_TYPE, to);
+          methodVisitor.visitInsn(Opcodes.F2I);
+          cast(methodVisitor, Type.INT_TYPE, to);
         }
       } else if (from == Type.LONG_TYPE) {
         if (to == Type.DOUBLE_TYPE) {
-          mv.visitInsn(Opcodes.L2D);
+          methodVisitor.visitInsn(Opcodes.L2D);
         } else if (to == Type.FLOAT_TYPE) {
-          mv.visitInsn(Opcodes.L2F);
+          methodVisitor.visitInsn(Opcodes.L2F);
         } else {
-          mv.visitInsn(Opcodes.L2I);
-          cast(Type.INT_TYPE, to);
+          methodVisitor.visitInsn(Opcodes.L2I);
+          cast(methodVisitor, Type.INT_TYPE, to);
         }
       } else {
         if (to == Type.BYTE_TYPE) {
-          mv.visitInsn(Opcodes.I2B);
+          methodVisitor.visitInsn(Opcodes.I2B);
         } else if (to == Type.CHAR_TYPE) {
-          mv.visitInsn(Opcodes.I2C);
+          methodVisitor.visitInsn(Opcodes.I2C);
         } else if (to == Type.DOUBLE_TYPE) {
-          mv.visitInsn(Opcodes.I2D);
+          methodVisitor.visitInsn(Opcodes.I2D);
         } else if (to == Type.FLOAT_TYPE) {
-          mv.visitInsn(Opcodes.I2F);
+          methodVisitor.visitInsn(Opcodes.I2F);
         } else if (to == Type.LONG_TYPE) {
-          mv.visitInsn(Opcodes.I2L);
+          methodVisitor.visitInsn(Opcodes.I2L);
         } else if (to == Type.SHORT_TYPE) {
-          mv.visitInsn(Opcodes.I2S);
+          methodVisitor.visitInsn(Opcodes.I2S);
         }
       }
     }
@@ -1204,6 +1215,16 @@ public class InstructionAdapter extends MethodVisitor {
    * @param type an array Type.
    */
   public void newarray(final Type type) {
+    newarray(mv, type);
+  }
+
+  /**
+   * Generates the instruction to create and push on the stack an array of the given type.
+   *
+   * @param methodVisitor the method visitor to use to generate the instruction.
+   * @param type an array Type.
+   */
+  static void newarray(final MethodVisitor methodVisitor, final Type type) {
     int arrayType;
     switch (type.getSort()) {
       case Type.BOOLEAN:
@@ -1231,10 +1252,10 @@ public class InstructionAdapter extends MethodVisitor {
         arrayType = Opcodes.T_DOUBLE;
         break;
       default:
-        mv.visitTypeInsn(Opcodes.ANEWARRAY, type.getInternalName());
+        methodVisitor.visitTypeInsn(Opcodes.ANEWARRAY, type.getInternalName());
         return;
     }
-    mv.visitIntInsn(Opcodes.NEWARRAY, arrayType);
+    methodVisitor.visitIntInsn(Opcodes.NEWARRAY, arrayType);
   }
 
   public void arraylength() {

asm-commons/src/main/java/org/objectweb/asm/commons/Remapper.java

@@ -110,8 +110,7 @@ public abstract class Remapper {
       String remappedInternalName = mapType(internalName);
       if (remappedInternalName != null) {
         if (remappedInternalNames == null) {
-          remappedInternalNames = new String[internalNames.length];
-          System.arraycopy(internalNames, 0, remappedInternalNames, 0, internalNames.length);
+          remappedInternalNames = internalNames.clone();
         }
         remappedInternalNames[i] = remappedInternalName;
       }

asm-commons/src/main/java/org/objectweb/asm/commons/SerialVersionUIDAdder.java

@@ -186,11 +186,10 @@ public class SerialVersionUIDAdder extends ClassVisitor {
     if (computeSvuid) {
       this.name = name;
       this.access = access;
-      this.interfaces = new String[interfaces.length];
+      this.interfaces = interfaces.clone();
       this.svuidFields = new ArrayList<>();
       this.svuidConstructors = new ArrayList<>();
       this.svuidMethods = new ArrayList<>();
-      System.arraycopy(interfaces, 0, this.interfaces, 0, interfaces.length);
     }
 
     super.visit(version, access, name, signature, superName, interfaces);

asm-commons/src/test/java/org/objectweb/asm/commons/AdviceAdapterTest.java

@@ -405,6 +405,44 @@ public class AdviceAdapterTest extends AsmTest {
     assertDoesNotThrow(() -> buildClassWithMethod(outputMethod).newInstance());
   }
 
+  @Test
+  public void testAllMethods_constructorWithJsrRet() {
+    Label label0 = new Label();
+    Label label1 = new Label();
+    Label label2 = new Label();
+    Label label3 = new Label();
+    MethodNode inputMethod =
+        new MethodNodeBuilder("<init>", "(I)V", 3, 3)
+            .trycatch(label0, label1, label1)
+            .label(label0)
+            .aload(0)
+            .methodInsn(Opcodes.INVOKESPECIAL, "C", "<init>", "()V", false)
+            // After instrumentation, expect a before advice here, before instruction #3.
+            .go(label3)
+            .label(label1)
+            .jsr(label2)
+            // After instrumentation, expect an after advice here, before instruction #6.
+            .athrow()
+            .label(label2)
+            .astore(2)
+            .ret(2)
+            .label(label3)
+            // After instrumentation, expect an after advice here, before instruction #11.
+            .vreturn()
+            .build();
+
+    MethodNode outputMethod = new MethodNode(Opcodes.ACC_PUBLIC, "<init>", "(I)V", null, null);
+    inputMethod.accept(new BasicAdviceAdapter(outputMethod));
+
+    MethodNode expectedMethod =
+        new ExpectedMethodBuilder(inputMethod)
+            .withBeforeAdviceAt(3)
+            .withAfterAdviceAt(6, 11)
+            .build();
+    assertEquals(toText(expectedMethod), toText(outputMethod));
+    assertDoesNotThrow(() -> buildClassWithMethod(outputMethod).newInstance());
+  }
+
   @Test
   public void testAllMethods_constructorWithLongsAndArrays() {
     MethodNode inputMethod =

asm-commons/src/test/java/org/objectweb/asm/commons/AnalyzerAdapterTest.java

@@ -218,10 +218,14 @@ public class AnalyzerAdapterTest extends AsmTest {
      */
     private ArrayList<Object> toFrameTypes(final List<Object> analyzerTypes) {
       ArrayList<Object> frameTypes = new ArrayList<>();
-      for (int i = 0; i < analyzerTypes.size(); ) {
+      for (int i = 0; i < analyzerTypes.size(); ++i) {
+        if (i > 0
+            && (analyzerTypes.get(i - 1) == Opcodes.LONG
+                || analyzerTypes.get(i - 1) == Opcodes.DOUBLE)) {
+          continue;
+        }
         Object value = analyzerTypes.get(i);
         frameTypes.add(value);
-        i += (value == Opcodes.LONG || value == Opcodes.DOUBLE) ? 2 : 1;
       }
       return frameTypes;
     }

asm-test/src/main/java/org/objectweb/asm/test/ClassFile.java

@@ -288,7 +288,7 @@ public class ClassFile {
     builder.add("magic: ", parser.u4());
     builder.add("minor_version: ", parser.u2());
     int majorVersion = parser.u2();
-    if (majorVersion > /* V12 = */ 56) {
+    if (majorVersion > /* V14 = */ 58) {
       throw new ClassFormatException("Unsupported class version");
     }
     builder.add("major_version: ", majorVersion);
@@ -1747,6 +1747,8 @@ public class ClassFile {
     }
 
     /**
+     * Returns the constant pool item with the given index.
+     *
      * @param <C> a CpInfo subclass.
      * @param cpIndex a constant pool entry index.
      * @param cpInfoType the expected type of the constant pool entry.
@@ -2335,7 +2337,7 @@ public class ClassFile {
   private abstract static class AbstractBuilder<T> implements ClassContext, MethodContext {
     /** Flag used to distinguish CpInfo keys in {@link #context}. */
     private static final int CP_INFO_KEY = 0xF0000000;
-    /** The parent node of this node. May be null. */
+    /** The parent node of this node. May be {@literal null}. */
     private final AbstractBuilder<?> parent;
     /** The children of this builder. */
     final ArrayList<T> children;

asm-tree/src/main/java/org/objectweb/asm/tree/ClassNode.java

@@ -207,15 +207,9 @@ public class ClassNode extends ClassVisitor {
   public AnnotationVisitor visitAnnotation(final String descriptor, final boolean visible) {
     AnnotationNode annotation = new AnnotationNode(descriptor);
     if (visible) {
-      if (visibleAnnotations == null) {
-        visibleAnnotations = new ArrayList<>(1);
-      }
-      visibleAnnotations.add(annotation);
+      visibleAnnotations = Util.add(visibleAnnotations, annotation);
     } else {
-      if (invisibleAnnotations == null) {
-        invisibleAnnotations = new ArrayList<>(1);
-      }
-      invisibleAnnotations.add(annotation);
+      invisibleAnnotations = Util.add(invisibleAnnotations, annotation);
     }
     return annotation;
   }
@@ -225,33 +219,21 @@ public class ClassNode extends ClassVisitor {
       final int typeRef, final TypePath typePath, final String descriptor, final boolean visible) {
     TypeAnnotationNode typeAnnotation = new TypeAnnotationNode(typeRef, typePath, descriptor);
     if (visible) {
-      if (visibleTypeAnnotations == null) {
-        visibleTypeAnnotations = new ArrayList<>(1);
-      }
-      visibleTypeAnnotations.add(typeAnnotation);
+      visibleTypeAnnotations = Util.add(visibleTypeAnnotations, typeAnnotation);
     } else {
-      if (invisibleTypeAnnotations == null) {
-        invisibleTypeAnnotations = new ArrayList<>(1);
-      }
-      invisibleTypeAnnotations.add(typeAnnotation);
+      invisibleTypeAnnotations = Util.add(invisibleTypeAnnotations, typeAnnotation);
     }
     return typeAnnotation;
   }
 
   @Override
   public void visitAttribute(final Attribute attribute) {
-    if (attrs == null) {
-      attrs = new ArrayList<>(1);
-    }
-    attrs.add(attribute);
+    attrs = Util.add(attrs, attribute);
   }
 
   @Override
   public void visitNestMember(final String nestMember) {
-    if (nestMembers == null) {
-      nestMembers = new ArrayList<>();
-    }
-    nestMembers.add(nestMember);
+    nestMembers = Util.add(nestMembers, nestMember);
   }
 
   @Override

asm-tree/src/main/java/org/objectweb/asm/tree/FieldNode.java

@@ -27,7 +27,6 @@
 // THE POSSIBILITY OF SUCH DAMAGE.
 package org.objectweb.asm.tree;
 
-import java.util.ArrayList;
 import java.util.List;
 import org.objectweb.asm.AnnotationVisitor;
 import org.objectweb.asm.Attribute;
@@ -143,15 +142,9 @@ public class FieldNode extends FieldVisitor {
   public AnnotationVisitor visitAnnotation(final String descriptor, final boolean visible) {
     AnnotationNode annotation = new AnnotationNode(descriptor);
     if (visible) {
-      if (visibleAnnotations == null) {
-        visibleAnnotations = new ArrayList<>(1);
-      }
-      visibleAnnotations.add(annotation);
+      visibleAnnotations = Util.add(visibleAnnotations, annotation);
     } else {
-      if (invisibleAnnotations == null) {
-        invisibleAnnotations = new ArrayList<>(1);
-      }
-      invisibleAnnotations.add(annotation);
+      invisibleAnnotations = Util.add(invisibleAnnotations, annotation);
     }
     return annotation;
   }
@@ -161,25 +154,16 @@ public class FieldNode extends FieldVisitor {
       final int typeRef, final TypePath typePath, final String descriptor, final boolean visible) {
     TypeAnnotationNode typeAnnotation = new TypeAnnotationNode(typeRef, typePath, descriptor);
     if (visible) {
-      if (visibleTypeAnnotations == null) {
-        visibleTypeAnnotations = new ArrayList<>(1);
-      }
-      visibleTypeAnnotations.add(typeAnnotation);
+      visibleTypeAnnotations = Util.add(visibleTypeAnnotations, typeAnnotation);
     } else {
-      if (invisibleTypeAnnotations == null) {
-        invisibleTypeAnnotations = new ArrayList<>(1);
-      }
-      invisibleTypeAnnotations.add(typeAnnotation);
+      invisibleTypeAnnotations = Util.add(invisibleTypeAnnotations, typeAnnotation);
     }
     return typeAnnotation;
   }
 
   @Override
   public void visitAttribute(final Attribute attribute) {
-    if (attrs == null) {
-      attrs = new ArrayList<>(1);
-    }
-    attrs.add(attribute);
+    attrs = Util.add(attrs, attribute);
   }
 
   @Override

asm-tree/src/main/java/org/objectweb/asm/tree/InsnList.java

@@ -35,7 +35,7 @@ import org.objectweb.asm.MethodVisitor;
  * A doubly linked list of {@link AbstractInsnNode} objects. <i>This implementation is not thread
  * safe</i>.
  */
-public class InsnList {
+public class InsnList implements Iterable<AbstractInsnNode> {
 
   /** The number of instructions in this list. */
   private int size;
@@ -151,6 +151,7 @@ public class InsnList {
    *
    * @return an iterator over the instructions in this list.
    */
+  @Override
   public ListIterator<AbstractInsnNode> iterator() {
     return iterator(0);
   }

asm-tree/src/main/java/org/objectweb/asm/tree/MethodNode.java

@@ -259,15 +259,9 @@ public class MethodNode extends MethodVisitor {
   public AnnotationVisitor visitAnnotation(final String descriptor, final boolean visible) {
     AnnotationNode annotation = new AnnotationNode(descriptor);
     if (visible) {
-      if (visibleAnnotations == null) {
-        visibleAnnotations = new ArrayList<>(1);
-      }
-      visibleAnnotations.add(annotation);
+      visibleAnnotations = Util.add(visibleAnnotations, annotation);
     } else {
-      if (invisibleAnnotations == null) {
-        invisibleAnnotations = new ArrayList<>(1);
-      }
-      invisibleAnnotations.add(annotation);
+      invisibleAnnotations = Util.add(invisibleAnnotations, annotation);
     }
     return annotation;
   }
@@ -277,15 +271,9 @@ public class MethodNode extends MethodVisitor {
       final int typeRef, final TypePath typePath, final String descriptor, final boolean visible) {
     TypeAnnotationNode typeAnnotation = new TypeAnnotationNode(typeRef, typePath, descriptor);
     if (visible) {
-      if (visibleTypeAnnotations == null) {
-        visibleTypeAnnotations = new ArrayList<>(1);
-      }
-      visibleTypeAnnotations.add(typeAnnotation);
+      visibleTypeAnnotations = Util.add(visibleTypeAnnotations, typeAnnotation);
     } else {
-      if (invisibleTypeAnnotations == null) {
-        invisibleTypeAnnotations = new ArrayList<>(1);
-      }
-      invisibleTypeAnnotations.add(typeAnnotation);
+      invisibleTypeAnnotations = Util.add(invisibleTypeAnnotations, typeAnnotation);
     }
     return typeAnnotation;
   }
@@ -309,29 +297,22 @@ public class MethodNode extends MethodVisitor {
         int params = Type.getArgumentTypes(desc).length;
         visibleParameterAnnotations = (List<AnnotationNode>[]) new List<?>[params];
       }
-      if (visibleParameterAnnotations[parameter] == null) {
-        visibleParameterAnnotations[parameter] = new ArrayList<>(1);
-      }
-      visibleParameterAnnotations[parameter].add(annotation);
+      visibleParameterAnnotations[parameter] =
+          Util.add(visibleParameterAnnotations[parameter], annotation);
     } else {
       if (invisibleParameterAnnotations == null) {
         int params = Type.getArgumentTypes(desc).length;
         invisibleParameterAnnotations = (List<AnnotationNode>[]) new List<?>[params];
       }
-      if (invisibleParameterAnnotations[parameter] == null) {
-        invisibleParameterAnnotations[parameter] = new ArrayList<>(1);
-      }
-      invisibleParameterAnnotations[parameter].add(annotation);
+      invisibleParameterAnnotations[parameter] =
+          Util.add(invisibleParameterAnnotations[parameter], annotation);
     }
     return annotation;
   }
 
   @Override
   public void visitAttribute(final Attribute attribute) {
-    if (attrs == null) {
-      attrs = new ArrayList<>(1);
-    }
-    attrs.add(attribute);
+    attrs = Util.add(attrs, attribute);
   }
 
   @Override
@@ -456,15 +437,11 @@ public class MethodNode extends MethodVisitor {
     // Add the annotation to this instruction.
     TypeAnnotationNode typeAnnotation = new TypeAnnotationNode(typeRef, typePath, descriptor);
     if (visible) {
-      if (currentInsn.visibleTypeAnnotations == null) {
-        currentInsn.visibleTypeAnnotations = new ArrayList<>(1);
-      }
-      currentInsn.visibleTypeAnnotations.add(typeAnnotation);
+      currentInsn.visibleTypeAnnotations =
+          Util.add(currentInsn.visibleTypeAnnotations, typeAnnotation);
     } else {
-      if (currentInsn.invisibleTypeAnnotations == null) {
-        currentInsn.invisibleTypeAnnotations = new ArrayList<>(1);
-      }
-      currentInsn.invisibleTypeAnnotations.add(typeAnnotation);
+      currentInsn.invisibleTypeAnnotations =
+          Util.add(currentInsn.invisibleTypeAnnotations, typeAnnotation);
     }
     return typeAnnotation;
   }
@@ -472,11 +449,9 @@ public class MethodNode extends MethodVisitor {
   @Override
   public void visitTryCatchBlock(
       final Label start, final Label end, final Label handler, final String type) {
-    if (tryCatchBlocks == null) {
-      tryCatchBlocks = new ArrayList<>(1);
-    }
-    tryCatchBlocks.add(
-        new TryCatchBlockNode(getLabelNode(start), getLabelNode(end), getLabelNode(handler), type));
+    TryCatchBlockNode tryCatchBlock =
+        new TryCatchBlockNode(getLabelNode(start), getLabelNode(end), getLabelNode(handler), type);
+    tryCatchBlocks = Util.add(tryCatchBlocks, tryCatchBlock);
   }
 
   @Override
@@ -485,15 +460,11 @@ public class MethodNode extends MethodVisitor {
     TryCatchBlockNode tryCatchBlock = tryCatchBlocks.get((typeRef & 0x00FFFF00) >> 8);
     TypeAnnotationNode typeAnnotation = new TypeAnnotationNode(typeRef, typePath, descriptor);
     if (visible) {
-      if (tryCatchBlock.visibleTypeAnnotations == null) {
-        tryCatchBlock.visibleTypeAnnotations = new ArrayList<>(1);
-      }
-      tryCatchBlock.visibleTypeAnnotations.add(typeAnnotation);
+      tryCatchBlock.visibleTypeAnnotations =
+          Util.add(tryCatchBlock.visibleTypeAnnotations, typeAnnotation);
     } else {
-      if (tryCatchBlock.invisibleTypeAnnotations == null) {
-        tryCatchBlock.invisibleTypeAnnotations = new ArrayList<>(1);
-      }
-      tryCatchBlock.invisibleTypeAnnotations.add(typeAnnotation);
+      tryCatchBlock.invisibleTypeAnnotations =
+          Util.add(tryCatchBlock.invisibleTypeAnnotations, typeAnnotation);
     }
     return typeAnnotation;
   }
@@ -506,12 +477,10 @@ public class MethodNode extends MethodVisitor {
       final Label start,
       final Label end,
       final int index) {
-    if (localVariables == null) {
-      localVariables = new ArrayList<>(1);
-    }
-    localVariables.add(
+    LocalVariableNode localVariable =
         new LocalVariableNode(
-            name, descriptor, signature, getLabelNode(start), getLabelNode(end), index));
+            name, descriptor, signature, getLabelNode(start), getLabelNode(end), index);
+    localVariables = Util.add(localVariables, localVariable);
   }
 
   @Override
@@ -527,15 +496,11 @@ public class MethodNode extends MethodVisitor {
         new LocalVariableAnnotationNode(
             typeRef, typePath, getLabelNodes(start), getLabelNodes(end), index, descriptor);
     if (visible) {
-      if (visibleLocalVariableAnnotations == null) {
-        visibleLocalVariableAnnotations = new ArrayList<>(1);
-      }
-      visibleLocalVariableAnnotations.add(localVariableAnnotation);
+      visibleLocalVariableAnnotations =
+          Util.add(visibleLocalVariableAnnotations, localVariableAnnotation);
     } else {
-      if (invisibleLocalVariableAnnotations == null) {
-        invisibleLocalVariableAnnotations = new ArrayList<>(1);
-      }
-      invisibleLocalVariableAnnotations.add(localVariableAnnotation);
+      invisibleLocalVariableAnnotations =
+          Util.add(invisibleLocalVariableAnnotations, localVariableAnnotation);
     }
     return localVariableAnnotation;
   }

asm-tree/src/main/java/org/objectweb/asm/tree/Util.java

@@ -40,6 +40,12 @@ final class Util {
 
   private Util() {}
 
+  static <T> List<T> add(final List<T> list, final T element) {
+    List<T> newList = list == null ? new ArrayList<>(1) : list;
+    newList.add(element);
+    return newList;
+  }
+
   static <T> List<T> asArrayList(final int length) {
     List<T> list = new ArrayList<>(length);
     for (int i = 0; i < length; ++i) {

asm-util/src/main/java/org/objectweb/asm/util/ASMifiable.java

-/**
- * ASM: a very small and fast Java bytecode manipulation framework Copyright (c) 2000-2011 INRIA,
- * France Telecom All rights reserved.
- *
- * <p>Redistribution and use in source and binary forms, with or without modification, are permitted
- * provided that the following conditions are met: 1. Redistributions of source code must retain the
- * above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions
- * in binary form must reproduce the above copyright notice, this list of conditions and the
- * following disclaimer in the documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the copyright holders nor the names of its contributors may be used to
- * endorse or promote products derived from this software without specific prior written permission.
- *
- * <p>THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
- * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
- * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-package org.objectweb.asm.util;
-
-import java.util.Map;
-import org.objectweb.asm.Label;
-
-/**
- * An {@link org.objectweb.asm.Attribute} that can generate the ASM code to create an equivalent
- * attribute.
- *
- * @author Eugene Kuleshov
- * @deprecated This interface is no longer supported (since ASM 7.1), because it uses a StringBuffer
- *     instead of a StringBuilder. Use {@link ASMifierSupport} instead.
- */
-@Deprecated
-// DontCheck(AbbreviationAsWordInName): can't be renamed (for backward binary compatibility).
-public interface ASMifiable {
-
-  /**
-   * Generates the ASM code to create an attribute equal to this attribute.
-   *
-   * @param outputBuffer where the generated code must be appended.
-   * @param visitorVariableName the name of the visitor variable in the produced code.
-   * @param labelNames the names of the labels in the generated code.
-   */
-  void asmify(StringBuffer outputBuffer, String visitorVariableName, Map<Label, String> labelNames);
-}