Upgrade to ASM 9.7.1

Closes gh-33821

Author: jhoeller

spring-core/src/main/java/org/springframework/asm/Attribute.java

@@ -44,11 +44,11 @@ public class Attribute {
   public final String type;
 
   /**
-   * The raw content of this attribute, only used for unknown attributes (see {@link #isUnknown()}).
-   * The 6 header bytes of the attribute (attribute_name_index and attribute_length) are <i>not</i>
-   * included.
+   * The raw content of this attribute, as returned by {@link
+   * #write(ClassWriter,byte[],int,int,int)}. The 6 header bytes of the attribute
+   * (attribute_name_index and attribute_length) are <i>not</i> included.
    */
-  private byte[] content;
+  private ByteVector cachedContent;
 
   /**
    * The next attribute in this attribute list (Attribute instances can be linked via this field to
@@ -93,7 +93,9 @@ public boolean isCodeAttribute() {
    *
    * @return the labels corresponding to this attribute, or {@literal null} if this attribute is not
    *     a Code attribute that contains labels.
+   * @deprecated no longer used by ASM.
    */
+  @Deprecated
   protected Label[] getLabels() {
     return new Label[0];
   }
@@ -115,7 +117,9 @@ protected Label[] getLabels() {
    *     attribute header bytes (attribute_name_index and attribute_length) are not taken into
    *     account here.
    * @param labels the labels of the method's code, or {@literal null} if the attribute to be read
-   *     is not a Code attribute.
+   *     is not a Code attribute. Labels defined in the attribute must be created and added to this
+   *     array, if not already present, by calling the {@link #readLabel} method (do not create
+   *     {@link Label} instances directly).
    * @return a <i>new</i> {@link Attribute} object corresponding to the specified bytes.
    */
   protected Attribute read(
@@ -126,16 +130,99 @@ protected Attribute read(
       final int codeAttributeOffset,
       final Label[] labels) {
     Attribute attribute = new Attribute(type);
-    attribute.content = new byte[length];
-    System.arraycopy(classReader.classFileBuffer, offset, attribute.content, 0, length);
+    attribute.cachedContent = new ByteVector(classReader.readBytes(offset, length));
     return attribute;
   }
 
+  /**
+   * Reads an attribute with the same {@link #type} as the given attribute. This method returns a
+   * new {@link Attribute} object, corresponding to the 'length' bytes starting at 'offset', in the
+   * given ClassReader.
+   *
+   * @param attribute The attribute prototype that is used for reading.
+   * @param classReader the class that contains the attribute to be read.
+   * @param offset index of the first byte of the attribute's content in {@link ClassReader}. The 6
+   *     attribute header bytes (attribute_name_index and attribute_length) are not taken into
+   *     account here.
+   * @param length the length of the attribute's content (excluding the 6 attribute header bytes).
+   * @param charBuffer the buffer to be used to call the ClassReader methods requiring a
+   *     'charBuffer' parameter.
+   * @param codeAttributeOffset index of the first byte of content of the enclosing Code attribute
+   *     in {@link ClassReader}, or -1 if the attribute to be read is not a Code attribute. The 6
+   *     attribute header bytes (attribute_name_index and attribute_length) are not taken into
+   *     account here.
+   * @param labels the labels of the method's code, or {@literal null} if the attribute to be read
+   *     is not a Code attribute. Labels defined in the attribute are added to this array, if not
+   *     already present.
+   * @return a new {@link Attribute} object corresponding to the specified bytes.
+   */
+  public static Attribute read(
+      final Attribute attribute,
+      final ClassReader classReader,
+      final int offset,
+      final int length,
+      final char[] charBuffer,
+      final int codeAttributeOffset,
+      final Label[] labels) {
+    return attribute.read(classReader, offset, length, charBuffer, codeAttributeOffset, labels);
+  }
+
+  /**
+   * Returns the label corresponding to the given bytecode offset by calling {@link
+   * ClassReader#readLabel}. This creates and adds the label to the given array if it is not already
+   * present. Note that this created label may be a {@link Label} subclass instance, if the given
+   * ClassReader overrides {@link ClassReader#readLabel}. Hence {@link #read(ClassReader, int, int,
+   * char[], int, Label[])} must not manually create {@link Label} instances.
+   *
+   * @param bytecodeOffset a bytecode offset in a method.
+   * @param labels the already created labels, indexed by their offset. If a label already exists
+   *     for bytecodeOffset this method does not create a new one. Otherwise it stores the new label
+   *     in this array.
+   * @return a label for the given bytecode offset.
+   */
+  public static Label readLabel(
+      final ClassReader classReader, final int bytecodeOffset, final Label[] labels) {
+    return classReader.readLabel(bytecodeOffset, labels);
+  }
+
+  /**
+   * Calls {@link #write(ClassWriter,byte[],int,int,int)} if it has not already been called and
+   * returns its result or its (cached) previous result.
+   *
+   * @param classWriter the class to which this attribute must be added. This parameter can be used
+   *     to add the items that corresponds to this attribute to the constant pool of this class.
+   * @param code the bytecode of the method corresponding to this Code attribute, or {@literal null}
+   *     if this attribute is not a Code attribute. Corresponds to the 'code' field of the Code
+   *     attribute.
+   * @param codeLength the length of the bytecode of the method corresponding to this code
+   *     attribute, or 0 if this attribute is not a Code attribute. Corresponds to the 'code_length'
+   *     field of the Code attribute.
+   * @param maxStack the maximum stack size of the method corresponding to this Code attribute, or
+   *     -1 if this attribute is not a Code attribute.
+   * @param maxLocals the maximum number of local variables of the method corresponding to this code
+   *     attribute, or -1 if this attribute is not a Code attribute.
+   * @return the byte array form of this attribute.
+   */
+  private ByteVector maybeWrite(
+      final ClassWriter classWriter,
+      final byte[] code,
+      final int codeLength,
+      final int maxStack,
+      final int maxLocals) {
+    if (cachedContent == null) {
+      cachedContent = write(classWriter, code, codeLength, maxStack, maxLocals);
+    }
+    return cachedContent;
+  }
+
   /**
    * Returns the byte array form of the content of this attribute. The 6 header bytes
    * (attribute_name_index and attribute_length) must <i>not</i> be added in the returned
    * ByteVector.
    *
+   * <p>This method is only invoked once to compute the binary form of this attribute. Subsequent
+   * changes to the attribute after it was written for the first time will not be considered.
+   *
    * @param classWriter the class to which this attribute must be added. This parameter can be used
    *     to add the items that corresponds to this attribute to the constant pool of this class.
    * @param code the bytecode of the method corresponding to this Code attribute, or {@literal null}
@@ -156,7 +243,39 @@ protected ByteVector write(
       final int codeLength,
       final int maxStack,
       final int maxLocals) {
-    return new ByteVector(content);
+    return cachedContent;
+  }
+
+  /**
+   * Returns the byte array form of the content of the given attribute. The 6 header bytes
+   * (attribute_name_index and attribute_length) are <i>not</i> added in the returned byte array.
+   *
+   * @param attribute The attribute that should be written.
+   * @param classWriter the class to which this attribute must be added. This parameter can be used
+   *     to add the items that corresponds to this attribute to the constant pool of this class.
+   * @param code the bytecode of the method corresponding to this Code attribute, or {@literal null}
+   *     if this attribute is not a Code attribute. Corresponds to the 'code' field of the Code
+   *     attribute.
+   * @param codeLength the length of the bytecode of the method corresponding to this code
+   *     attribute, or 0 if this attribute is not a Code attribute. Corresponds to the 'code_length'
+   *     field of the Code attribute.
+   * @param maxStack the maximum stack size of the method corresponding to this Code attribute, or
+   *     -1 if this attribute is not a Code attribute.
+   * @param maxLocals the maximum number of local variables of the method corresponding to this code
+   *     attribute, or -1 if this attribute is not a Code attribute.
+   * @return the byte array form of this attribute.
+   */
+  public static byte[] write(
+      final Attribute attribute,
+      final ClassWriter classWriter,
+      final byte[] code,
+      final int codeLength,
+      final int maxStack,
+      final int maxLocals) {
+    ByteVector content = attribute.maybeWrite(classWriter, code, codeLength, maxStack, maxLocals);
+    byte[] result = new byte[content.length];
+    System.arraycopy(content.data, 0, result, 0, content.length);
+    return result;
   }
 
   /**
@@ -221,7 +340,7 @@ final int computeAttributesSize(
     Attribute attribute = this;
     while (attribute != null) {
       symbolTable.addConstantUtf8(attribute.type);
-      size += 6 + attribute.write(classWriter, code, codeLength, maxStack, maxLocals).length;
+      size += 6 + attribute.maybeWrite(classWriter, code, codeLength, maxStack, maxLocals).length;
       attribute = attribute.nextAttribute;
     }
     return size;
@@ -308,7 +427,7 @@ final void putAttributes(
     Attribute attribute = this;
     while (attribute != null) {
       ByteVector attributeContent =
-          attribute.write(classWriter, code, codeLength, maxStack, maxLocals);
+          attribute.maybeWrite(classWriter, code, codeLength, maxStack, maxLocals);
       // Put attribute_name_index and attribute_length.
       output.putShort(symbolTable.addConstantUtf8(attribute.type)).putInt(attributeContent.length);
       output.putByteArray(attributeContent.data, 0, attributeContent.length);

spring-core/src/main/java/org/springframework/asm/ClassReader.java

@@ -188,13 +188,14 @@ public ClassReader(
    * @param classFileOffset the offset in byteBuffer of the first byte of the ClassFile to be read.
    * @param checkClassVersion whether to check the class version or not.
    */
+  @SuppressWarnings("PMD.ConstructorCallsOverridableMethod")
   ClassReader(
       final byte[] classFileBuffer, final int classFileOffset, final boolean checkClassVersion) {
     this.classFileBuffer = classFileBuffer;
     this.b = classFileBuffer;
     // Check the class' major_version. This field is after the magic and minor_version fields, which
     // use 4 and 2 bytes respectively.
-    if (checkClassVersion && readShort(classFileOffset + 6) > Opcodes.V23) {
+    if (checkClassVersion && readShort(classFileOffset + 6) > Opcodes.V24) {
       throw new IllegalArgumentException(
           "Unsupported class file major version " + readShort(classFileOffset + 6));
     }
@@ -340,7 +341,7 @@ private static byte[] readStream(final InputStream inputStream, final boolean cl
   private static int computeBufferSize(final InputStream inputStream) throws IOException {
     int expectedLength = inputStream.available();
     /*
-     * Some implementations can return 0 while holding available data (for example, new
+     * Some implementations can return 0 while holding available data (e.g. new
      * FileInputStream("/proc/a_file")). Also in some pathological cases a very small number might
      * be returned, and in this case we use a default size.
      */
@@ -2311,7 +2312,7 @@ private void readCode(
           {
             // A forward jump with an offset > 32767. In this case we automatically replace ASM_GOTO
             // with GOTO_W, ASM_JSR with JSR_W and ASM_IFxxx <l> with IFNOTxxx <L> GOTO_W <l> L:...,
-            // where IFNOTxxx is the "opposite" opcode of ASMS_IFxxx (for example, IFNE for ASM_IFEQ) and
+            // where IFNOTxxx is the "opposite" opcode of ASMS_IFxxx (e.g. IFNE for ASM_IFEQ) and
             // where <L> designates the instruction just after the GOTO_W.
             // First, change the ASM specific opcodes ASM_IFEQ ... ASM_JSR, ASM_IFNULL and
             // ASM_IFNONNULL to IFEQ ... JSR, IFNULL and IFNONNULL.
@@ -3603,6 +3604,20 @@ public int readByte(final int offset) {
     return classFileBuffer[offset] & 0xFF;
   }
 
+  /**
+   * Reads several bytes in this {@link ClassReader}. <i>This method is intended for {@link
+   * Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
+   *
+   * @param offset the start offset of the bytes to be read in this {@link ClassReader}.
+   * @param length the number of bytes to read.
+   * @return the read bytes.
+   */
+  public byte[] readBytes(final int offset, final int length) {
+    byte[] result = new byte[length];
+    System.arraycopy(classFileBuffer, offset, result, 0, length);
+    return result;
+  }
+
   /**
    * Reads an unsigned short value in this {@link ClassReader}. <i>This method is intended for
    * {@link Attribute} sub classes, and is normally not needed by class generators or adapters.</i>

spring-core/src/main/java/org/springframework/asm/ClassWriter.java

@@ -264,13 +264,7 @@ public ClassWriter(final ClassReader classReader, final int flags) {
     super(/* latest api = */ Opcodes.ASM9);
     this.flags = flags;
     symbolTable = classReader == null ? new SymbolTable(this) : new SymbolTable(this, classReader);
-    if ((flags & COMPUTE_FRAMES) != 0) {
-      compute = MethodWriter.COMPUTE_ALL_FRAMES;
-    } else if ((flags & COMPUTE_MAXS) != 0) {
-      compute = MethodWriter.COMPUTE_MAX_STACK_AND_LOCAL;
-    } else {
-      compute = MethodWriter.COMPUTE_NOTHING;
-    }
+    setFlags(flags);
   }
 
   // -----------------------------------------------------------------------------------------------
@@ -1020,6 +1014,28 @@ public int newNameType(final String name, final String descriptor) {
     return symbolTable.addConstantNameAndType(name, descriptor);
   }
 
+  /**
+   * Changes the computation strategy of method properties like max stack size, max number of local
+   * variables, and frames.
+   *
+   * <p><b>WARNING</b>: {@link #setFlags(int)} method changes the behavior of new method visitors
+   * returned from {@link #visitMethod(int, String, String, String, String[])}. The behavior will be
+   * changed only after the next method visitor is returned. All the previously returned method
+   * visitors keep their previous behavior.
+   *
+   * @param flags option flags that can be used to modify the default behavior of this class. Must
+   *     be zero or more of {@link #COMPUTE_MAXS} and {@link #COMPUTE_FRAMES}.
+   */
+  public final void setFlags(final int flags) {
+    if ((flags & ClassWriter.COMPUTE_FRAMES) != 0) {
+      compute = MethodWriter.COMPUTE_ALL_FRAMES;
+    } else if ((flags & ClassWriter.COMPUTE_MAXS) != 0) {
+      compute = MethodWriter.COMPUTE_MAX_STACK_AND_LOCAL;
+    } else {
+      compute = MethodWriter.COMPUTE_NOTHING;
+    }
+  }
+
   // -----------------------------------------------------------------------------------------------
   // Default method to compute common super classes when computing stack map frames
   // -----------------------------------------------------------------------------------------------

spring-core/src/main/java/org/springframework/asm/MethodVisitor.java

@@ -30,19 +30,20 @@
 /**
  * A visitor to visit a Java method. The methods of this class must be called in the following
  * order: ( {@code visitParameter} )* [ {@code visitAnnotationDefault} ] ( {@code visitAnnotation} |
- * {@code visitAnnotableParameterCount} | {@code visitParameterAnnotation} {@code
+ * {@code visitAnnotableParameterCount} | {@code visitParameterAnnotation} | {@code
  * visitTypeAnnotation} | {@code visitAttribute} )* [ {@code visitCode} ( {@code visitFrame} |
  * {@code visit<i>X</i>Insn} | {@code visitLabel} | {@code visitInsnAnnotation} | {@code
  * visitTryCatchBlock} | {@code visitTryCatchAnnotation} | {@code visitLocalVariable} | {@code
- * visitLocalVariableAnnotation} | {@code visitLineNumber} )* {@code visitMaxs} ] {@code visitEnd}.
- * In addition, the {@code visit<i>X</i>Insn} and {@code visitLabel} methods must be called in the
- * sequential order of the bytecode instructions of the visited code, {@code visitInsnAnnotation}
- * must be called <i>after</i> the annotated instruction, {@code visitTryCatchBlock} must be called
- * <i>before</i> the labels passed as arguments have been visited, {@code
- * visitTryCatchBlockAnnotation} must be called <i>after</i> the corresponding try catch block has
- * been visited, and the {@code visitLocalVariable}, {@code visitLocalVariableAnnotation} and {@code
- * visitLineNumber} methods must be called <i>after</i> the labels passed as arguments have been
- * visited.
+ * visitLocalVariableAnnotation} | {@code visitLineNumber} | {@code visitAttribute} )* {@code
+ * visitMaxs} ] {@code visitEnd}. In addition, the {@code visit<i>X</i>Insn} and {@code visitLabel}
+ * methods must be called in the sequential order of the bytecode instructions of the visited code,
+ * {@code visitInsnAnnotation} must be called <i>after</i> the annotated instruction, {@code
+ * visitTryCatchBlock} must be called <i>before</i> the labels passed as arguments have been
+ * visited, {@code visitTryCatchBlockAnnotation} must be called <i>after</i> the corresponding try
+ * catch block has been visited, and the {@code visitLocalVariable}, {@code
+ * visitLocalVariableAnnotation} and {@code visitLineNumber} methods must be called <i>after</i> the
+ * labels passed as arguments have been visited. Finally, the {@code visitAttribute} method must be
+ * called before {@code visitCode} for non-code attributes, and after it for code attributes.
  *
  * @author Eric Bruneton
  */

spring-core/src/main/java/org/springframework/asm/Opcodes.java

@@ -288,6 +288,7 @@ public interface Opcodes {
   int V21 = 0 << 16 | 65;
   int V22 = 0 << 16 | 66;
   int V23 = 0 << 16 | 67;
+  int V24 = 0 << 16 | 68;
 
   /**
    * Version flag indicating that the class is using 'preview' features.

spring-core/src/main/java/org/springframework/asm/Symbol.java

@@ -178,7 +178,9 @@ abstract class Symbol {
    *   <li>the symbol's value for {@link #CONSTANT_INTEGER_TAG},{@link #CONSTANT_FLOAT_TAG}, {@link
    *       #CONSTANT_LONG_TAG}, {@link #CONSTANT_DOUBLE_TAG},
    *   <li>the CONSTANT_MethodHandle_info reference_kind field value for {@link
-   *       #CONSTANT_METHOD_HANDLE_TAG} symbols,
+   *       #CONSTANT_METHOD_HANDLE_TAG} symbols (or this value left shifted by 8 bits for
+   *       reference_kind values larger than or equal to H_INVOKEVIRTUAL and if the method owner is
+   *       an interface),
    *   <li>the CONSTANT_InvokeDynamic_info bootstrap_method_attr_index field value for {@link
    *       #CONSTANT_INVOKE_DYNAMIC_TAG} symbols,
    *   <li>the offset of a bootstrap method in the BootstrapMethods boostrap_methods array, for